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Athens, Greece

The National and Kapodistrian University of Athens , usually referred to simply as the University of Athens, has been in continuous operation since its establishment in 1837. It is the oldest higher education institution in the modern Greek state. Wikipedia.

Sfetsos K.,National and Kapodistrian University of Athens | Siampos K.,University of Bern
Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics | Year: 2015

The all-loop anisotropic Thirring model interpolates between the WZW model and the non-Abelian T-dual of the anisotropic principal chiral model. We focus on the SU(2) case and we prove that it is classically integrable by providing its Lax pair formulation. We derive its underlying symmetry current algebra and use it to show that the Poisson brackets of the spatial part of the Lax pair, assume the Maillet form. In this way we procure the corresponding r and s matrices which provide non-trivial solutions to the modified Yang-Baxter equation. © 2015 The Authors.

Duntas L.H.,National and Kapodistrian University of Athens
Hormone and Metabolic Research | Year: 2015

Iodine and selenium (Se) are both essential elements to thyroid hormone economy, while they represent key players in the development of autoimmune thyroiditis. Chronic high iodine intake has been associated in various studies with increased frequency of autoimmune thyroiditis. In susceptible individuals, iodine excess increases intra-thyroid infiltrating Th17 cells and inhibits T regulatory (TREG) cells development, while it triggers an abnormal expression of tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) in thyrocytes, thus inducing apoptosis and parenchymal destruction. As was shown in a mouse model, high iodine supply leads to changes in the immunogenicity of the thyroglobulin molecule, upregulation of vascular intercellular adhesion molecule-1 (ICAM-1), and reactive oxygen species (ROS) generation in the thyrocytes. Serum Se levels were found decreased in Hashimoto thyroiditis and especially in Graves' disease as well as in thyroid-associated ophthalmopathy patients, the levels being related to the pathogenesis and outcome. Selenium is strongly involved, via the variable selenoproteins, in antioxidant, redox, and anti-inflammatory processes. Selenium enhances CD4+/CD25 FOXP3 and T regulatory cells activity while suppressing cytokine secretion, thus preventing apoptosis of the follicular cells and providing protection from thyroiditis. Selenium supplementation may be useful in autoimmune thyroid diseases, though, while usually well-tolerated, it should not be universally recommended, and it is also likely to be helpful for those with low Se status and autoimmunity. Broadly speaking, the achievement and maintenance of selenostasis as well as adequate urinary iodine excretion are mandatory to control disease, while, putatively, they may additionally be critical to preventing disease. © Georg Thieme Verlag KG Stuttgart New York.

Tsiodras S.,National and Kapodistrian University of Athens
BMC infectious diseases | Year: 2014

Patients with severe viral infections are often hospitalized in intensive care units (ICUs) and recent studies underline the frequency of viral detection in ICU patients. Viral infections in the ICU often involve the respiratory or the central nervous system and can cause significant morbidity and mortality especially in immunocompromised patients. The mainstay of therapy of viral infections is supportive care and antiviral therapy when available. Increased understanding of the molecular mechanisms of viral infection has provided great potential for the discovery of new antiviral agents that target viral proteins or host proteins that regulate immunity and are involved in the viral life cycle. These novel treatments need to be further validated in animal and human randomized controlled studies.

Rahiotis C.,National and Kapodistrian University of Athens
Journal of oral science | Year: 2010

We evaluated the curing efficiency of 4 high-intensity light-emitting diode (LED) devices by assessing percentage of residual C=C (%RDB), surface microhardness (SM), depth of cure (DC), percentage of linear shrinkage-strain (%LS), and percentage of wall-to-wall contraction (%WWC). The light-curing units tested were a QTH light, the Elipar TriLight (3M/ESPE), and 4 LED devices - the Allegro (Denmat), the Bluephase (Ivoclar/Vivadent), the FreeLight2 (3M/ESPE), and The Cure TC-01 (Spring Health Products). The %RDB was measured by microFTIR spectroscopy. Microhardness measurements (Vickers) were performed at the surface (H0) and at depths of 3 mm (H3) and 5 mm (H5) of cylindrical specimens. Depth of cure was expressed as the ratio of microhardness at each depth, relative to the corresponding surface value (H3/H0 and H5/H0). The bonded disc method was used to evaluate %LS. For the %WWC evaluation, cylindrical resin restorations were imaged by high resolution micro-CT and the %WWC was calculated at depths of 0 mm and 2 mm. There were no statistical differences among the LEDs in %RDB or %LS. The Bluephase and Allegro had the highest SM values. As compared with the other LEDs, the Bluephase and The Cure TC-01 had lower values for depth of cure at depths of 3 mm and 5 mm. There were no significant differences in %WWC among the LEDs at either depth, and the QTH had the lowest %WWC at both depths.

Christodoulou N.G.,University of Nottingham | Christodoulou G.N.,National and Kapodistrian University of Athens
Psychotherapy and Psychosomatics | Year: 2013

Economic crises are chronic stress situations and as such are likely to have psychological and psychopathological consequences. Indeed, they produce adaptive responses (normal sadness) and dysfunctional responses (mainly depression and suicidal potential). Managing the psychological consequences of financial crises is a complex undertaking, which may include political intervention. Diagnosing depression and suicide potential is important anyway but acquires greater importance during periods of economic crisis. The financial crisis in Greece has adversely affected the physical and mental health of the population. Reports from Greece are particularly relevant because on the basis of them one may predict what is likely to happen in other countries ('contagion' of the mental health effects of the crisis), especially those with similar cultural and societal characteristics. Unemployment, poverty and debt have been associated with psychiatric morbidity and suicide, and therefore measures to counter them may reduce harm. Welfare provision can limit psychiatric morbidity during periods of economic crisis, and active labour market programmes and family support programmes have been found to be effective and cost-effective. The measures to limit crisisprovoked morbidity should be culture specific. Psychiatry can respond to the challenges posed by economic crises through its holistic, biopsychosocial and person-centred ethos. Important steps include promoting advocacy and empowerment on a personal level and solidarity and social cohesion on a societal level. Furthermore, mental health professionals can help enhance resilience and mental capital for those suffering from economic crises. Mental illness prevention and mental health promotion should be integral parts of clinical management and service planning in times of financial crisis. Mental health professionals should highlight the cost-effectiveness of mental health investments. © 2013 S. Karger AG, Basel.

Heikkinen T.,University of Turku | Tsolia M.,National and Kapodistrian University of Athens | Finn A.,University of Bristol
Pediatric Infectious Disease Journal | Year: 2013

Despite ample evidence for the great burden that annual influenza epidemics place on children and society in general, few European countries currently recommend influenza vaccination of healthy children of any age. The most frequently cited reasons for reluctance to extend general vaccine recommendations to children include the view that influenza is a mild illness of limited clinical importance, lack of country-specific data on disease burden, uncertainty about the efficacy and safety of influenza vaccines in children and inadequate evidence of cost-effectiveness of vaccinating children. In recent years, several clinical studies have provided new and important information that help address many of these areas of question and concern. In light of this newly available scientific evidence, influenza vaccine recommendations for children should be properly reevaluated in all European countries. Furthermore, to allow for variation in costs and patterns of healthcare delivery between different countries, cost-effectiveness analyses of influenza vaccination of healthy children should be performed in each country or region. Finally, increased efforts should be made to educate both healthcare professionals and the great public about recent findings and advances in the field of pediatric influenza. Copyright © 2013 Lippincott Williams &Wilkins.

Pournaras S.,University of Thessaly | Poulou A.,Serres General Hospital | Tsakris A.,National and Kapodistrian University of Athens
Journal of Antimicrobial Chemotherapy | Year: 2010

Enterobacteriaceae clinical strains that produce the class A carbapenem-hydrolysing enzyme KPC (Klebsiella pneumoniae carbapenemase) are increasingly reported worldwide, and are already endemic in North and South America, China, Israel and Greece. The accurate detection of KPC enzymes is of utmost importance for containing the global spread of KPC producers. Currently, the detection of putative carbapenemase production is based on an initial phenotypic screen for carbapenem resistance followed by the modified Hodge test (MHT) as a confirmatory test. However, the MHT is often difficult to interpret, is not specific for carbapenemase activity due to KPC and there are reports of false-positive results with CTX-M-positive or AmpC-hyper-producing Enterobacteriaceae. Boronic acid compounds are serine-type β-lactamase inhibitors that were employed originally for the detection of class C plasmidic AmpCs in Enterobacteriaceae. Recently, they have also been evaluated for the differentiation of KPC-producing Enterobacteriaceae. In that respect, combined-disc tests using carbapenems with and without phenylboronic acid (PBA) have been proposed as the most accurate phenotypic tests for detecting KPC production. When these disc tests are extended to include carbapenem discs with EDTA or both PBA and EDTA on the same plate, the production of metallo-β-lactamase (MBL) or both KPC and MBL, respectively, can also be accurately detected. Phenotypic tests based on the inhibitory activity of boronic acid compounds are very easy to perform and interpret, and may be applied from the first day of isolation of the suspected resistant Enterobacteriaceae. We think that they could effectively replace MHT for the convenient and early detection of KPC carbapenemases in regions where these enzymes are common. © The Author 2010.

Dunjko V.,University of Edinburgh | Dunjko V.,Ruder Boskovic Institute | Dunjko V.,Heriot - Watt University | Wallden P.,Heriot - Watt University | And 2 more authors.
Physical Review Letters | Year: 2014

Quantum digital signatures (QDSs) allow the sending of messages from one sender to multiple recipients, with the guarantee that messages cannot be forged or tampered with. Additionally, messages cannot be repudiated - if one recipient accepts a message, she is guaranteed that others will accept the same message as well. While messaging with these types of security guarantees are routinely performed in the modern digital world, current technologies only offer security under computational assumptions. QDSs, on the other hand, offer security guaranteed by quantum mechanics. All thus far proposed variants of QDSs require long-term, high quality quantum memory, making them unfeasible in the foreseeable future. Here, we present a QDS scheme where no quantum memory is required, which also needs just linear optics. This makes QDSs feasible with current technology. © Published by American Physical Society.

Duntas L.H.,National and Kapodistrian University of Athens
Annales d'Endocrinologie | Year: 2011

Thyroid autoimmune disease, a multifactorial organ-specific autoimmune disorder, is marking a constant increase worldwide. It is thought to be caused by multiple environmental factors triggering autoimmune response in genetically susceptible individuals, though the exact mechanisms linking environmental factors to thyroid autoimmunity are not as yet well understood. Nevertheless, there is increasing evidence that mainly nutritive factors and environmental pollution by metals and chemicals (e.g. organochlorines, pesticides) are the main factors in the present-day spread of this disease. This review presents an overview of the current knowledge regarding environmental factors, their association with genetics and their impact on the immune system. © 2011 Elsevier Masson SAS.

Patokos T.,National and Kapodistrian University of Athens
Theoretical Medicine and Bioethics | Year: 2011

In game theory, the word 'game' is used to describe any interdependence between interacting parties, and the Nash equilibrium is a prominent tool for analysing such interactions. I argue that the concept of the Nash equilibrium may also be used in non-gaming contexts. An individual is in a Nash equilibrium if his or her beliefs are consistent with his or her actions. Given that discordance between beliefs and behaviour is a typical cause of psychiatric disorders, individuals who are not in a Nash equilibrium are likely to be affected by such disorders. In this regard, the concept of the Nash equilibrium could aptly be introduced into the medical practitioner's vocabulary for describing a patient's mental health status. © 2011 Springer Science+Business Media B.V.

Nassis G.P.,National and Kapodistrian University of Athens
Journal of Strength and Conditioning Research | Year: 2013

Nassis, GP. Effect of altitude on football performance: Analysis of the 2010 FIFA World Cup data. J Strength Cond Res 27(3): 703-707, 2013-Laboratory studies show that altitude ascent impairs endurance performance. Limited data exist on football, and information from official matches is very scarce even for other team sports. The aim of this study was to examine the effect of altitude on football performance during the 2010 World Cup in South Africa. It was hypothesized that (a) total distance covered, an index of endurance, would be reduced above the altitude of 580 m, and (b) technical skills would be affected because altitude alters ball flight characteristics. Physical performance, goals scored, and goalkeepers' errors that resulted in goals conceded were recorded from the official game statistics of Fédération Internationale de Football Association during the South Africa 2010 World Cup. Matches were played at sea level (altitude: 0 m), 660, 1200-1400, and 1401-1753 m. After testing for data normality, mean differences were checked with a one-way analysis of variance. Results show a 3.1% lower total distance that was covered by the teams during the matches played at 1200-1400 and 1401-1753 m (p < 0.05) compared with sea level. Indices of technical skills, including number of goals scored per game and errors made by the goalkeepers that resulted in goals conceded, did not differ with altitude. It is concluded that playing football above 1200 m had negative effects on endurance but not on technical skills during World Cup 2010 matches. It seems that teams should follow several days of acclimatization before playing at altitude as low as 1200 m, to ameliorate the negative effects of altitude on physical performance. © 2013 National Strength and Conditioning Association.

Bamias A.,National and Kapodistrian University of Athens | Pignata S.,Italian National Cancer Institute | Pujade-Lauraine E.,University of Paris Descartes
Critical Reviews in Oncology/Hematology | Year: 2012

Ovarian cancer is the leading cause of death from gynecological cancers. Primary treatment of advanced ovarian cancer (FIGO stages III and IV) until recently consisted of cytoreductive surgery and paclitaxel/carboplatin chemotherapy. The results of two randomized studies, showing prolongation of progression-free survival (PFS) by the addition of the anti-VEGF monoclonal antibody, bevacizumab, led to the approval of this agent for first-line treatment of this disease and indicate that angiogenesis is a promising therapeutic target. Angiogenesis is essential for oncogenesis but also the viability and expansion of ovarian cancer. Specifically, VEGF is involved in the formation of ascites and has a direct effect on ascites tumor cells as well as an immunosuppressive function. Apart from VEGF, PDGF, FGF and angiopoietins present a therapeutic interest. We are reviewing the results of published clinical studies using anti-angiogenic factors in advanced ovarian cancer. © 2012 Elsevier Ireland Ltd.

Vitoratos N.,National and Kapodistrian University of Athens
Journal of pregnancy | Year: 2012

Preeclampsia is one of the leading causes of maternal morbidity/mortality. The pathogenesis of preeclampsia is still under investigation. The aim of this paper is to present the molecular mechanisms implicating in the pathway leading to preeclampsia.

Kapsalaki M.,University of Porto | Leal V.,University of Porto | Santamouris M.,National and Kapodistrian University of Athens
Energy and Buildings | Year: 2012

This work developed a methodology and an associated calculation platform in order to identify the economic efficient design solutions for residential Net Zero Energy Building (NZEB) design considering the influence of the local climate, the endogenous energy resources and the local economic conditions. One case study of a detached house for 3 climates was analyzed with the tool developed in order to gain insights on the economic space of NZEB solutions and the influence of the climatic context. A methodology for assisting the choice of economically efficient NZEB solutions from the early design stage is now available. Its use in practice may be of great relevance as the results showed that the differences between an economically efficient and economically inefficient NZEB can be over three times both in terms of initial and life cycle cost. © 2012 Elsevier B.V. All rights reserved.

Kontzoglou K.,National and Kapodistrian University of Athens
Chirurgia (Bucharest, Romania : 1990) | Year: 2011

Dermatofibrosarcoma protuberans (DFSP) is an uncommon soft tissue tumor of cutaneous origin of intermediate grade malignant potential. The incidence of DFSP is 0.1% of all cancers and 1% of all soft tissue sarcomas. We present the case of a 65years old female with a palpable, painful mass on the right thigh. A surgical excision of the lesion was done and the histopathology, as well as the immunohistochemical analysis with CD-34, confirmed the diagnosis of DFSP. Two years later, the patient is free of disease and no local recurrences or metastases have been found. Wide radical excision is the preferred surgical method for therapy of DFSP without distant metastasis. Furthermore, DFSP resists to conventional chemotherapy and radiation therapy, while, in cases of metastasis, therapy depends on cytogenesis and molecular biology of the tumor, so new therapeutic strategies are under research.

Stavropoulou M.,National and Kapodistrian University of Athens
International Journal of Rock Mechanics and Mining Sciences | Year: 2014

The discontinuity spacing density function is theoretically found by applying the first principles of the Maximum Entropy Theory. It is shown that this function is the negative exponential probability density function. Then, the analytical relation between RQD and discontinuity frequency that may be derived, provided that discontinuity sets follow the negative exponential model, is validated against simulation data. It is also found that if the discontinuity spacings follow the negative exponential distribution, then the number of fractures per length measured along scanlines or drilled cores follow quite well the two-parameter Weibull distribution function. Subsequently, following the methodology proposed originally by Hudson and Priest, the closed-form expression of block volume distribution in a rock mass transected by three mutually orthogonal discontinuity sets is found. Also, the left-truncated block volume proportion above a certain block volume size is found analytically. The theoretical results referring to discontinuity frequency and block volume distributions are finally successfully validated against measurements carried out on drill cores and exposed walls, in a dolomitic marble quarry. The methodology presented herein can be applied to rock engineering applications that necessitate the characterization of rock mass discontinuities and discontinuity spacings are reasonably well represented by the negative exponential probability density function. The proposed method for the prediction of marble block volume distribution was applied to data from a quarry from drill cores and scanlines on exposed quarry walls.© 2013 .

Vassilopoulos D.,National and Kapodistrian University of Athens
European Journal of Internal Medicine | Year: 2011

It is well established that hepatitis B virus (HBV) reactivation is common among patients with various hematological or neoplastic diseases who receive chemotherapeutic agents without appropriate antiviral prophylaxis and is associated with significant morbidity and mortality. A number of recent studies have indicated that treatment with anti-tumor necrosis factor (TNF) agents in patients with autoimmune/rheumatic diseases carries a similar risk. Furthermore, appropriate pre-emptive treatment with oral antivirals appears to significantly reduce that risk and should be routinely implemented in clinical practice. Similar data are available for B-cell depleting agents like rituximab from the hematology literature, indicating the need for a similar approach in patients with autoimmune diseases receiving such agents. © 2011 European Federation of Internal Medicine. Published by Elsevier B.V. All rights reserved.

Diakakis M.,National and Kapodistrian University of Athens
Journal of Flood Risk Management | Year: 2014

This work focuses on flooding phenomena in Athens metropolitan area in Greece. To this end, based on a flood-event database aggregated with civil protection and documentary spatial evidence, an exhaustive inventory of floods in the area is developed, including events not previously studied. Fifty-two floods are identified between 1880 and 2010, in various locations around Athens basin, which caused 182 casualties and substantial damage. Analysis of the inventory shows an increase in flood occurrence during autumn, especially November, and a rise in flood frequency in recent decades. Spatial information is used to identify the segments of the drainage network that overflowed in each of these flooding episodes. Geographic information system-based spatial analysis of all the events indicates that certain sections of the drainage network, particularly in the central and north-western parts of the study area, are the most vulnerable to flood phenomena. © 2013 The Chartered Institution of Water and Environmental Management (CIWEM) and John Wiley & Sons Ltd.

Fleming P.S.,Queen Mary, University of London | Koletsi D.,National and Kapodistrian University of Athens | Seehra J.,GKT Dental Institute | Pandis N.,University of Bern
Journal of Clinical Epidemiology | Year: 2014

Objectives To compare the methodological quality of systematic reviews (SRs) published in high- and low-impact factor (IF) Core Clinical Journals. In addition, we aimed to record the implementation of aspects of reporting, including Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) flow diagram, reasons for study exclusion, and use of recommendations for interventions such as Grading of Recommendations Assessment, Development and Evaluation (GRADE). Study Design and Setting We searched PubMed for systematic reviews published in Core Clinical Journals between July 1 and December 31, 2012. We evaluated the methodological quality using the Assessment of Multiple Systematic Reviews (AMSTAR) tool. Results Over the 6-month period, 327 interventional systematic reviews were identified with a mean AMSTAR score of 63.3% (standard deviation, 17.1%), when converted to a percentage scale. We identified deficiencies in relation to a number of quality criteria including delineation of excluded studies and assessment of publication bias. We found that SRs published in higher impact journals were undertaken more rigorously with higher percentage AMSTAR scores (per IF unit: β = 0.68%; 95% confidence interval: 0.32, 1.04; P < 0.001), a discrepancy likely to be particularly relevant when differences in IF are large. Conclusion Methodological quality of SRs appears to be better in higher impact journals. The overall quality of SRs published in many Core Clinical Journals remains suboptimal. © 2014 The Authors. Published by Elsevier Inc. All rights reserved.

Xanthoulis A.,Section of Gastroenterological Surgery | Tiniakos D.G.,National and Kapodistrian University of Athens
World Journal of Gastroenterology | Year: 2013

E2F family of transcription factors regulates various cellular functions related to cell cycle and apoptosis. Its individual members have traditionally been classified into activators and repressors, based on in vitro studies. However their contribution in human cancer is more complicated and difficult to predict. We review current knowledge on the expression of E2Fs in digestive system malignancies and its clinical implications for patient prognosis and treatment. E2F1, the most extensively studied member and the only one with prognostic value, exhibits a tumor-suppressing activity in esophageal, gastric and colorectal adenocarcinoma, and in hepatocellular carcinoma (HCC), whereas in pancreatic ductal adenocarcinoma and esophageal squamous cell carcinoma may function as a tumorpromoter. In the latter malignancies, E2F1 immunohistochemical expression has been correlated with higher tumor grade and worse patient survival, whereas in esophageal, gastric and colorectal adenocarcinomas is a marker of increased patient survival. E2F2 has only been studied in colorectal cancer, where its role is not considered significant. E2F4's role in colorectal, gastric and hepatic carcinogenesis is tumor-promoting. E2F8 is strongly upregulated in human HCC, thus possibly contributing to hepatocarcinogenesis. Adenoviral transfer of E2F as gene therapy to sensitize pancreatic cancer cells for chemotherapeutic agents has been used in experimental studies. Other therapeutic strategies are yet to be developed, but it appears that targeted approaches using E2F-agonists or antagonists should take into account the tissue-dependent function of each E2F member. Further understanding of E2Fs' contribution in cellular functions in vivo would help clarify their role in carcinogenesis. © 2013 Baishideng. All rights reserved.

Piagkou M.,National and Kapodistrian University of Athens
International journal of oral science | Year: 2010

Running through the infratemporal fossa is the lingual nerve (i.e. the third branch of the posterior trunk of the mandibular nerve). Due to its location, there are various anatomic structures that might entrap and potentially compress the lingual nerve. These anatomical sites of entrapment are: (a) the partially or completely ossified pterygospinous or pterygoalar ligaments; (b) the large lamina of the lateral plate of the pterygoid process; and (c) the medial fibers of the anterior region of the lateral pterygoid muscle. Due to the connection between these nerve and anatomic structures, a contraction of the lateral pterygoid muscle, for example, might cause a compression of the lingual nerve. Any variations in the course of the lingual nerve can be of clinical significance to surgeons and neurologists because of the significant complications that might occur. To name a few of such complications, lingual nerve entrapment can lead to: (a) numbness, hypoesthesia or even anesthesia of the tongue's mucous glands; (b) anesthesia and loss of taste in the anterior two-thirds of the tongue; (c) anesthesia of the lingual gums; and (d) pain related to speech articulation disorder. Dentists should, therefore, be alert to possible signs of neurovascular compression in regions where the lingual nerve is distributed.

Stamatakos M.,National and Kapodistrian University of Athens
Chirurgia (Bucharest, Romania : 1990) | Year: 2010

Carcinoid tumors are malignancies originating from neuroendocrine cells, most commonly encountered in the gastrointestinal tract, in a rate of 64%, with the majority affecting the ileum. Certain genetic syndromes sometimes include carcinoid tumors in their phenotype. These malignancies may be rather asymptomatic, although occasionally they behave aggressively. They are typically diagnosed due to the effects of a locally advanced disease, or when producing symptoms because of hormone secretion (carcinoid syndrome). A better understanding of their molecular biology and behavior is demanded so that these tumors to be diagnosed precociously and managed effectively.

Nathanail A.,Academy of Athens | Nathanail A.,National and Kapodistrian University of Athens | Contopoulos I.,Academy of Athens
Astrophysical Journal | Year: 2014

We investigate the structure of the steady-state force-free magnetosphere around a Kerr black hole in various astrophysical settings. The solution Ψ(r, θ) depends on the distributions of the magnetic field line angular velocity ω(Ψ) and the poloidal electric current I(Ψ). These are obtained self-consistently as eigenfunctions that allow the solution to smoothly cross the two singular surfaces of the problem, the inner light surface inside the ergosphere, and the outer light surface, which is the generalization of the pulsar light cylinder. Magnetic field configurations that cross both singular surfaces (e.g., monopole, paraboloidal) are uniquely determined. Configurations that cross only one light surface (e.g., the artificial case of a rotating black hole embedded in a vertical magnetic field) are degenerate. We show that, similar to pulsars, black hole magnetospheres naturally develop an electric current sheet that potentially plays a very important role in the dissipation of black hole rotational energy and in the emission of high-energy radiation. © 2014. The American Astronomical Society. All rights reserved.

Skiada A.,National and Kapodistrian University of Athens
Skinmed | Year: 2013

Mucormycosis is an invasive fungal infection caused by fungi of the order Mucorales, mainly affecting immunocompromised patients. Cutaneous mucormycosis is the third most common clinical form of the disease, after pulmonary and rhino-cerebral. The usual factors predisposing to this infection are hematological malignancies and diabetes mellitus, but a significant proportion of patients are immunocompetent. The agents of mucormycosis are ubiquitous in nature and are transmitted to the skin by direct inoculation, as a result of various types of trauma. These include needle sticks, stings and bites by animals, motor vehicle accidents, natural disasters, and burn injuries. The typical presentation of mucormycosis is the necrotic eschar, but it can present with various other signs. The infection can be locally invasive and penetrate into the adjacent fat, muscle, fascia, and bone, or become disseminated. Diagnosis is difficult because of the nonspecific findings of mucormycosis. Biopsy and culture should be performed. The treatment of mucormycosis is multimodal and consists of surgical debridement, use of antifungal drugs (amphotericin B and posaconazole), and reversal of underlying risk factors, when possible. Mortality rates, although lower than in other forms of the disease, are significant, ranging from 4% to 10% when the infection is localized.

Dalakas M.C.,Thomas Jefferson University | Dalakas M.C.,National and Kapodistrian University of Athens
Autoimmunity Reviews | Year: 2012

The most common autoimmune muscle disorders include dermatomyositis (DM), polymyositis (PM), necrotizing autoimmune myositis (NAM) and sporadic inclusion body myositis (sIBM). DM is a complement-mediated microangiopathy leading to destruction of capillaries, hypoperfusion and inflammatory cell stress on the perifascicular regions. NAM is an increasingly recognized subacute myopathy triggered by statins, viral infections, cancer or autoimmunity with macrophages as the final effector cells causing fiber injury. PM and IBM are T cell-mediated disorders where cytotoxic CD8 + T cells clonally expand in situ and invade major histocompatibility complex class I expressing muscle fibers. In sIBM, in addition to autoreactive T cells, there are degenerative features characterized by vacuolization and accumulation of stressor or amyloid-related misfolded proteins; an interrelationship between inflammatory and degeneration-associated molecules is prominent and enhances the cascade of pathogenic factors. These disorders are treatable, hence the need to make the correct diagnosis from the outset. The applied therapeutic strategies are outlined and the promising new agents are reviewed. © 2011.

Chatziralli I.P.,Veroia General Hospital | Sergentanis T.N.,National and Kapodistrian University of Athens
Ophthalmology | Year: 2011

Purpose: To evaluate risk factors (hypertension, diabetes mellitus, and current tamsulosin, alfuzosin, terazosin, or doxazosin use) for intraoperative floppy iris syndrome (IFIS) in patients undergoing phacoemulsification cataract surgery. Design: Systematic review and meta-analysis of the literature. Participants: Seventeen eligible studies (17 588 eyes) examining the association between IFIS and risk factors. Methods: Pertinent publications were identified through a systematic search of PubMed. All references of relevant reviews and eligible articles were also screened. Language restrictions were not used, and data were extracted from each eligible study by 2 investigators working independently. For medications, 2 separate analyses were performed: an analysis using a dichotomous criterion (use/non-use of the examined agent) and an alternative analysis performing comparisons with patients not receiving any α1-blocker. The fixed-effects model (Mantel-Haenszel method) or the random-effects (DerSimonian Laird) model was appropriately used to calculate the pooled odds ratio (OR). Publication bias was appropriately assessed. Main Outcome Measures: Pooled OR for the incidence of IFIS. Results: The pooled OR for IFIS after tamsulosin use was approximately 40-fold greater (or 16.5 at the alternative analysis) than that after alfuzosin use, that is, the second α1-blocker in order of effect size. Alfuzosin and terazosin were also associated with IFIS with comparable ORs; the effect of doxazosin reached formal statistical significance at the alternative analysis. Intraoperative floppy iris syndrome was positively associated with hypertension (pooled OR = 2.2, 95% confidence interval [CI], 1.2-4.2, fixed effects) but not with diabetes mellitus (pooled OR = 1.3, 95% CI, 0.7-2.2, fixed effects). Conclusions: This meta-analysis has highlighted a hierarchy concerning the role of α1-blockers in IFIS, indicating an extremely sizeable effect size of tamsulosin; this may entail important physiologic implications. Alfuzosin, terazosin, and doxazosin presented with comparable effect sizes. Hypertension, but not diabetes mellitus, emerged as a risk factor for IFIS. Financial Disclosure(s): The author(s) have no proprietary or commercial interest in any materials discussed in this article. © 2011 American Academy of Ophthalmology.

Souras N.,National and Kapodistrian University of Athens
International Orthopaedics | Year: 2013

Osteochondral lesion of the talus (OLT) is a broad term used to describe an injury or abnormality of the talar articular cartilage and adjacent bone. A variety of terms have been used to refer to this clinical entity, including osteochondritis dissecans (OCD), osteochondral fracture and osteochondral defect. Whether OLT is a precursor to more generalised arthrosis of the ankle remains unclear, but the condition is often symptomatic enough to warrant treatment. In more than one third of cases, conservative treatment is unsuccessful, and surgery is indicated. There is a wide variety of treatment strategies for osteochondral defects of the ankle, with new techniques that have substantially increased over the last decade. The common treatment strategies of symptomatic osteochondral lesions include nonsurgical treatment, with rest, cast immobilisation and use of nonsteroidal anti-inflammatory drugs (NSAIDs). Surgical options are lesion excision, excision and curettage, excision combined with curettage and microfracturing, filling the defect with autogenous cancellous bone graft, antegrade (transmalleolar) drilling, retrograde drilling, fixation and techniques such as osteochondral transplantation [osteochondral autograft transfer system (OATS)] and autologous chondrocyte implantation (ACI). Furthermore, smaller lesions are symptomatic and when left untreated, OCDs can progress; current treatment strategies have not solved this problem. The target of these treatment strategies is to relieve symptoms and improve function. Publications on the efficacy of these treatment strategies vary. In most cases, several treatment options are viable, and the choice of treatment is based on defect type and size and preferences of the treating clinician. © 2013 Springer-Verlag Berlin Heidelberg.

Hadziyannis S.J.,National and Kapodistrian University of Athens
Liver International | Year: 2011

There have been numerous research milestones since the discovery of the hepatitis B virus (HBV) in the 1960s. These mark major advances in the serology and epidemiology of HBV infection, in indentifying the wide clinical spectrum of acute and chronic hepatic diseases as well as the extrahepatic conditions induced by this virus, the molecular biology of the virus including its variants and mutants, its molecular diagnosis and monitoring, the host immune responses to the infecting virus, the pathogenesis and immunopathogenesis of liver disease as well as its natural course and outcome. These landmark discoveries are the firm background for current and future developments in treatment. There are three consecutive and partly overlapping chronological periods to treatment milestones beginning with recombinant standard interferon-alpha (IFN-α) in the 1980s, then oral antivirals from 1998 to the present and in 2005 pegylated IFN-α (PEG-IFN). The renewed interest in PEG-IFN-α treatment is now focused on both HBeAg-positive and HBeAg-negative chronic hepatitis B and it now also aims at HBsAg loss when associated with on-treatment monitoring of serum HBV DNA and HBsAg levels, resulting in the closest thing to a cure of hepatitis B. The impressive progress made in all aspects of hepatitis B research suggests that curative therapy may be developed for all patients and for all phases of HBV infection in the foreseeable future. However for the moment, realistic efforts should be made to make treatment as widely available and affordable as possible and to apply current therapies to significantly reduce HBV morbidity and mortality. © 2011 John Wiley & Sons A/S.

Papatheodoridis G.V.,National and Kapodistrian University of Athens
Liver International | Year: 2011

Current agents used in the treatment of chronic hepatitis B (CHB) can be classified into interferons-α (IFN-α: standard or pegylated) and nucleos(t)ide analogues (NUCs). NUCs are now used in most CHB patients for several reasons. They can be given to all CHB patients, even those with contraindications to IFN-α. NUCs are more convenient to use (one oral tablet daily) than IFN-α (subcutaneous injections) and are well tolerated with a good safety profile, while IFN-α has frequent and potentially severe side effects and worsens the patient's quality of life. All NUCs are potent anti-hepatitis B virus agents (all except adefovir are more potent than IFN-α) with entecavir and tenofovir being the most potent. Most importantly NUCs all have minimal risk of resistance during long-term monotherapy. Prolongation of entecavir or tenofovir monotherapy maintains and slightly increases the initially high virological remission rates (67-76% of HBeAg-positive and 90-93% of HBeAg-negative patients) and this is expected to result in improved long-term outcomes. The need for long-term, perhaps indefinite, treatment is the main limitation of NUCs and the finite duration (48 weeks) the main advantage of IFN-α. However, only a minority of IFN-α-treated patients achieve durable sustained off-treatment responses (HBeAg-positive: 30-35%, HBeAg-negative: 20-25%), while NUCs may be safely discontinued in HBeAg-positive patients with stable HBeAg seroconversion. Because there will always be concerns for safety and family planning issues with long-term therapy, NUCs should be used judiciously and should not be prescribed in young CHB patients with mild liver disease. © 2011 John Wiley & Sons A/S.

Emmanouilidou E.,Biomedical Research Foundation of the Academy of Athens BRFAA | Stefanis L.,Biomedical Research Foundation of the Academy of Athens BRFAA | Stefanis L.,National and Kapodistrian University of Athens | Vekrellis K.,Biomedical Research Foundation of the Academy of Athens BRFAA
Neurobiology of Aging | Year: 2010

Proteasomal dysfunction may play a role in neurodegenerative conditions and protein aggregation. Overexpression in neuronal cells of α-synuclein, a molecule linked to Parkinson's Disease, may lead to proteasomal dysfunction. Using PC12 cells stably expressing wild-type or mutant α-synuclein and gel filtration, we demonstrate that soluble, intermediate size oligomers of α-synuclein co-elute with the 26S proteasome. These soluble oligomers associate with the 26S proteasome and are significantly increased following treatment with proteasomal, but not lysosomal, inhibitors, indicating specific degradation of these particular species by the 26S proteasome. Importantly, expression of α-synuclein resulted in a significant inhibition of all proteasomal activities without affecting the levels or assembly of the 26S proteasome. Pharmacological dissociation of α-synuclein oligomers restored proteasomal function and reduced polyubiquitinated protein load in intact cells. Our findings suggest a model where only a subset of specific soluble cell-derived α-synuclein oligomers is targeted to the 26S proteasome for degradation, and simultaneously inhibit its function, likely by impeding access of other proteasomal substrates. © 2008 Elsevier Inc.

Sarris A.,National and Kapodistrian University of Athens
Agricultural Economics (United Kingdom) | Year: 2013

This introductory paper highlights the key attributes of weather index insurance, and summarizes the major points and conclusions of the three subsequent papers included in the special issue. © 2013 International Association of Agricultural Economists.

Vassilatou E.,National and Kapodistrian University of Athens
World Journal of Gastroenterology | Year: 2014

Nonalcoholic fatty liver disease (NAFLD) is the most common cause of chronic liver disease in the Western world comprising a spectrum of liver damage from fatty liver infiltration to end-stage liver disease, in patients without significant alcohol consumption. Increased prevalence of NAFLD has been reported in patients with polycystic ovary syndrome (PCOS), one of the most common endocrinopathies in premenopausal women, which has been redefined as a reproductive and metabolic disorder after the recognition of the important role of insulin resistance in the pathophysiology of the syndrome. Obesity, in particular central adiposity and insulin resistance are considered as the main factors related to NAFLD in PCOS. Moreover, existing data support that androgen excess, which is the main feature of PCOS and is interrelated to insulin resistance, may be an additional contributing factor to the development of NAFLD. Although the natural history of NAFLD remains unclear and hepatic steatosis seems to be a relatively benign condition in most patients, limited data imply that advanced stage of liver disease is possibly more frequent in obese PCOS patients with NAFLD. PCOS patients, particularly obese patients with features of the metabolic syndrome, should be submitted to screening for NAFLD comprising assessment of serum amino-transferase levels and of hepatic steatosis by abdominal ultrasound. Lifestyle modifications including diet, weight loss and exercise are the most appropriate initial therapeutic interventions for PCOS patients with NAFLD. When pharmacologic therapy is considered, metformin may be used, although currently there is no medical therapy of proven benefit for NAFLD. Long-term follow up studies are needed to clarify clinical implications and guide appropriate diagnostic evaluation, follow-up protocol and optimal treatment for PCOS patients with NAFLD. © 2014 Baishideng Publishing Group Inc. All rights reserved.

Rideout H.J.,Biomedical Research Foundation of the Academy of Athens | Stefanis L.,Biomedical Research Foundation of the Academy of Athens | Stefanis L.,National and Kapodistrian University of Athens
Neurochemical Research | Year: 2014

Leucine-rich repeat kinase 2 (LRRK2) is a large, widely expressed protein of largely unknown function. Mutations in the gene encoding LRRK2 have been linked to multiple diseases, including a prominent association with familial and sporadic Parkinson's disease (PD), as well as inflammatory bowel disorders such as Crohn's disease. The LRRK2 protein possesses both kinase and GTPase signaling domains, as well as multiple protein interaction domains. Experimental studies in both cellular and in vivo models of mutant LRRK2-induced neurodegeneration have given clues to potential function(s) of LRRK2, yet much remains unknown. For example, while it is known that intact kinase and GTPase activity are required for mutant forms of the protein to trigger cell death, the specific targets of these enzymatic activities that mediate the death of neurons are not known. In this review, we discuss the evidence linking LRRK2 to various cellular/neuronal activities such as extrinsic death and inflammatory signaling, lysosomal protein degradation, the cytoskeletal system and neurite outgrowth, vesicle trafficking, mitochondrial dysfunction, as well as multiple points of interaction with several other genes linked to the pathogenesis of PD. In order for more effective therapeutic strategies to be envisioned and implemented, the mechanisms underlying LRRK2-mediated neurodegeneration need to be better characterized. Furthermore, insights into LRRK2-associated PD pathogenesis can potentially advance our understanding of the more common sporadic forms of PD. © 2013 Springer Science+Business Media.

Duntas L.H.,National and Kapodistrian University of Athens | Bernardini R.,University of Catania
Thyroid | Year: 2010

Background: Sorafenib (BAY 43-9006) is an inhibitor of multiple-receptor tyrosine kinases involved in tumor growth and angiogenesis, which can be advantageously administered orally. Initially used as monotherapy in advanced renal cell carcinoma, sorafenib was proven to increase progression-free survival while enhancing disease control. Clinical trials on sorafenib are at present ongoing for the treatment of various malignancies, including thyroid cancer (TC). Summary: Specifically, in two phase II studies recently conducted on papillary TC, although the respective results were not entirely compatible as regard partial response rate and progression-free survival, sorafenib demonstrated a relatively favorable benefit/risk profile. In another more recent phase II study, whose primary endpoint was the reinduction of radioactive iodine uptake at 26 weeks, although no reinduction of radioactive iodine uptake was observed, 59% had a beneficial response and 34% had stable disease. Sorafenib hence appears to be a valid alternative to conventional treatment of metastatic papillary TC refractory to radioiodine therapy. Conclusions: Further prospective investigations are required to define the characteristics of tumor response to the drug and the factors inducing resistance to treatment. A major issue demanding immediate attention involves optimization of sorafenib treatment: this concerns multidrug combination with different tyrosine kinase inhibitors or immunomodulating agents with the aim of reducing doses and thereby improving drug tolerability and antineoplastic capability. © 2010, Mary Ann Liebert, Inc.

Florou D.,National and Kapodistrian University of Athens
Tumour biology : the journal of the International Society for Oncodevelopmental Biology and Medicine | Year: 2012

Gastric cancer constitutes one of the most common neoplasms globally. Kallikrein-related peptidases have attracted interest as potential tumor markers and future targets for novel cancer therapeutics. We have recently reported KLK13 clinical importance as a favorable prognostic biomarker for gastric cancer patients' survival. By aiming to explore how the molecular profile of KLK13 is modified in stomach cancer cells treated with antineoplastic drugs, we examined, for the first time, the mRNA alterations of this gene following gastric cancer cells' exposure to the prominent chemotherapeutic substances epirubicin, oxaliplatin, or methotrexate. The antiproliferative effects of these agents, on AGS cells' growth, were determined by the 3-(4,5-dimethyl thiazol-2-yl)-2,5-diphenyl tetrazolium bromide and trypan blue assays. Total RNA, isolated from the harvested cells, was reverse-transcribed to cDNA. KLK13 levels were quantified via real-time PCR using the SYBR Green chemistry. The relative changes of KLK13 expression were calculated with the comparative C (t) (2(-ddCt)) method. Distinct KLK13 profiles resulted from AGS cells' incubation with epirubicin or methotrexate for 24, 36, and 48 h. KLK13 expression increased in a time-dependent manner up to 5.70 times (for epirubicin) or 5.76 times (for methotrexate) at 48 h compared with the corresponding untreated cells. According to our results, KLK13 expression is implicated in the molecular pathways that are triggered after administration of anticancer agents on gastric cancer cells. Moreover, our data support the possibility that KLK13 may be exploited as a future molecular predictor of gastric cancer cells' response to chemotherapy.

Giamarellos-Bourboulis E.J.,National and Kapodistrian University of Athens
International Journal of Antimicrobial Agents | Year: 2010

The enormous case-fatality rate of severe sepsis and septic shock has resulted in considerable efforts being made towards understanding their complex mechanisms of pathogenesis. This has been done with the hope that agents that interfere with the pathways of pathogenesis and modulate the immune response of the host may be candidates for therapy. Disappointing results from most trials of immunomodulators in sepsis have led to understanding that the progression of patients to multiple organ dysfunction syndrome involves blunting of the pro-inflammatory cytokine storm. Instead, the compensatory anti-inflammatory response syndrome (CARS) develops, which is characterised by immunoparalysis. Components of this syndrome are impaired phagocytosis by neutrophils, decreased expression of HLA-DR on monocytes, impairment of ex vivo cytokine stimulation of monocytes, CD4 lymphopenia due to apoptosis of lymphocytes and predominance of anti-inflammatory T h2 and regulatory T-cell responses over pro-inflammatory T h1 and T 17 responses. CARS is not the sole explanation for the failure of trials of immunomodulators in sepsis. Recent data from the Hellenic Sepsis Study Group demonstrate that components of CARS upon transition from sepsis to severe sepsis/shock differ in relation to the underlying type of infection. These data underscore that the pathogenesis of sepsis presents considerable heterogeneity from one patient to another. That heterogeneity should be taken into consideration when deciding to administer an immunomodulator. © 2010 Elsevier B.V. and the International Society of Chemotherapy.

Schmidt J.,University of Gottingen | Dalakas M.C.,National and Kapodistrian University of Athens
Expert Review of Clinical Immunology | Year: 2013

Inclusion body myositis is the most common inflammatory myopathy above the age of 50. It becomes clinically apparent around the fourth decade and leads to a slowly, but relentlessly progressive decline in muscular wasting and weakness. The pathology consists of a complex network of inflammatory and degenerative mechanisms, which lead to an attack of muscle fibers by auto-reactive T cells and possibly antibodies. At the same time, various aberrant proteins accumulate within the muscle fibers, including β-amyloid, tau and α-synuclein. Several key components of proinflammatory cell stress mechanisms such as nitric oxide production and macroautophagic processing contribute to the muscle fiber damage. So far, none of the anti-inflammatory or immunomodulatory treatment efforts have been able to halt the disease progression and help the patients. In this summary, the current concept of the complex disease pathology of IBM is reviewed with a focus on recent findings as well as future treatment perspectives. © 2013 Informa UK Ltd.

Fingerhut A.,National and Kapodistrian University of Athens
Surgical Innovation | Year: 2012

The adequate number of lymph nodes that should be examined to correctly stage colorectal cancer is still debated. Even though the guidelines state that 12 should be the minimum, there is ongoing concern that this might not be enough. Moreover, many studies have shown that this cut-off is far from universally obtained in many surgical series, whether via laparotomy or via laparoscopy. Arguments in favor of sticking to the cutoff value of 12 are weak: certainly, culling and examining as many lymph nodes as possible should increase the chances of correct staging and the consequent therapeutic consequences, decrease local recurrence and, perhaps, also increase survival (although this is not the direct consequence of gathering and examining as many lymph nodes as possible). Laparoscopy should be no different from open surgery: the same rational prevails for laparoscopic oncologic clearance to increase patient well-being and ensure good practice. What is most important, however, is to make surgeons and pathologists realize that this issue is important and that all of us should strive, in close collaboration, to achieve these goals, for the good of the patient, the person for whom the lymph node count counts most. © The Author(s) 2012.

Nikolopoulos T.P.,National and Kapodistrian University of Athens
Otology & neurotology : official publication of the American Otological Society, American Neurotology Society [and] European Academy of Otology and Neurotology | Year: 2010

AIM: To undertake a systematic review of the literature on acoustic neuroma growth. Predictors of growth were also explored. MATERIALS AND METHODS: A comprehensive search was conducted to identify the relevant literature. The search yielded 2,455 papers. All titles were reviewed by 2 of the authors, and finally, 41 papers were found reporting data pertinent to growth. RESULTS: The percentage of acoustic neuromas exhibiting growth ranges widely from 18 to 73%. The percentage of tumors reported not to grow for some years after diagnosis ranges from 9 to 75%. Some (usually less than 10%, but up to 22%) may get smaller. No reliable predictors of growth have been identified. The mean growth rate for all tumors varies between 1 and 2 mm/yr, and for only those that grow, between 2 and 4 mm/yr. However, there are cases with significant regression or exceptional growth (exceeding 18 mm/yr). There are various patterns of growth, and a tumor that shows growth may stop doing so and vice versa. Finally, some tumors that have been stable for many years can exhibit tumor growth. CONCLUSION: The growth pattern of acoustic neuromas is variable and incompletely understood. As much as 75% of tumors have been reported to show no growth, supporting a "wait and rescan" policy in many patients, although there are no reliable predictors of tumor behavior, and some tumors may grow rapidly. Primary longitudinal studies are needed to better define the natural history and limit unnecessary interventions.

Sakellis I.,National and Kapodistrian University of Athens
Applied Physics Letters | Year: 2011

In this paper by employing various experimental facts for different classes of materials, two critical conditions are derived, which lead to the empirically used scaling relations describing the ac response of disordered nonmetals. In parallel the origin of time-temperature superposition is explored while the scenario of time-pressure (or/temperature) superposition is introduced. Moreover, a unified equation for the entire frequency range of ac conductivity is proposed. The results are physically visualized within the frame of percolation theory, attempting to establish a link to the dominant approaches of Hunt [Philos. Mag. B 81, 875 (2001)] and Dyre [J. Appl. Phys. 64, 2456 (1988)]. © 2011 American Institute of Physics.

Gkouvatsos K.,Lady Davis Institute for Medical Research | Gkouvatsos K.,McGill University | Papanikolaou G.,National and Kapodistrian University of Athens | Pantopoulos K.,Lady Davis Institute for Medical Research | Pantopoulos K.,McGill University
Biochimica et Biophysica Acta - General Subjects | Year: 2012

Background: Iron is utilized by several proteins as cofactor for major biological processes. However, iron may also harm cells by catalyzing the generation of free radicals and promoting oxidative stress. Acquisition, transport, utilization and storage of iron are tightly controlled to meet physiological needs and prevent excessive accumulation of the metal within cells. Plasma transferrin has been known for years as a central player in iron metabolism, assigned to circulate iron in a soluble, non-toxic form and deliver it to the erythron and other tissues. Recent data uncovered an additional role of transferrin as an upstream regulator of hepcidin, a liver-derived peptide hormone that controls systemic iron traffic. Scope of review: Here, we review basic features of iron metabolism, highlighting the function of transferrin in iron transport and cellular iron uptake. We further discuss the role of hepcidin as an orchestrator of systemic iron homeostasis, and the mechanisms underlying hepcidin regulation in response to various physiological cues. Emphasis is given on the role of transferrin on iron-dependent hepcidin regulation. Major conclusions: Transferrin exerts a crucial function in the maintenance of systemic iron homeostasis as component of a plasma iron sensing system that modulates hepcidin expression. General significance: Proper expression of transferrin and hepcidin are essential for health, and disruption of their regulatory circuits is associated with iron-related disorders. This article is part of a Special Issue entitled Transferrins: Molecular mechanisms of iron transport and disorders. © 2011 Elsevier B.V. All rights reserved.

Panagopoulos D.J.,National and Kapodistrian University of Athens | Panagopoulos D.J.,Radiation and Environmental Biophysics Research Center
Cell Biochemistry and Biophysics | Year: 2012

In the present experiments the effect of GSM radiation on ovarian development of virgin Drosophila melanogaster female insects was studied. Newly emerged adult female flies were collected and divided into separate identical groups. After the a lapse of certain number of hours-different for each group-the insects (exposed and sham-exposed) were dissected and their intact ovaries were collected and photographed under an optical microscope with the same magnification. The size of the ovaries was compared between exposed and sham-exposed virgin female insects, during the time needed for the completion of oogenesis and maturation of the first eggs in the ovarioles. Immediately after the intact ovaries were photographed, they were further dissected into individual ovarioles and treated for TUNEL and acridine-orange assays to determine the degree of DNA damage in the egg chamber cells. The study showed that the ovarian size of the exposed insects is significantly smaller than that of the corresponding sham-exposed insects, due to destruction of egg chambers by the GSM radiation, after DNA damage and consequent cell death induction in the egg chamber cells of the virgin females as shown in previous experiments on inseminated females. The difference in ovarian size between sham-exposed and exposed virgin female flies becomes most evident 39-45 h after eclosion when the first eggs within the ovaries are at the late vitellogenic and post-vitellogenic stages (mid-late oogenesis). More than 45 h after eclosion, the difference in ovarian size decreases, as the first mature eggs of the sham-exposed insects are leaving the ovaries and are laid. © 2012 Springer Science+Business Media, LLC.

Saridakis E.N.,National and Kapodistrian University of Athens
Nuclear Physics B | Year: 2010

We investigate quintom evolution in power-law potentials. We extract the early-time, tracker solutions, under the assumption of matter domination. Additionally, we derive analytical solutions at intermediate times, that is at low redshifts, which is the period during the transition from matter to dark-energy domination. A comparison with exact evolution reveals that the tracker solutions are valid within 98% for z ≳ 1.5, while the intermediate ones are accurate within 98% up to z ≈ 0.5. Using these expressions we extract two new w-parametrizations, one in terms of the redshift and one in terms of the dark-energy density-parameter, and we present various quintom evolution sub-classes, including quintessence-like or phantom-like cases, realization of the -1-crossing, and non-monotonic w-evolution. © 2010 Elsevier B.V. All rights reserved.

Cholongitas E.,Aristotle University of Thessaloniki | Papatheodoridis G.V.,National and Kapodistrian University of Athens
World Journal of Gastroenterology | Year: 2013

The progress in treatment against hepatitis B virus (HBV) with the development of effective and well tolerated nucleotide analogues (NAs) has improved the outcome of patients with HBV decompensated cirrhosis and has prevented post-transplant HBV recurrence. This review summarizes updated issues related to the management of patients with HBV infection before and after liver transplantation (LT). A literature search using the PubMed/Medline databases and consensus documents was performed. Pre-transplant therapy has been initially based on lamivudine, but entecavir and tenofovir represent the currently recommended first-line NAs for the treatment of patients with HBV decompensated cirrhosis. After LT, the combination of HBV immunoglobulin (HBIG) and NA is considered as the standard of care for prophylaxis against HBV recurrence. The combination of HBIG and lamivudine is related to higher rates of HBV recurrence, compared to the HBIG and entecavir or tenofovir combination. In HBIG-free prophylactic regimens, entecavir and tenofovir should be the first-line options. The choice of treatment for HBV recurrence depends on prior prophylactic therapy, but entecavir and tenofovir seem to be the most attractive options. Finally, liver grafts from hepatitis B core antibody (anti-HBc) positive donors can be safely used in hepatitis B surface antigen negative, preferentially anti-HBc/anti-hepatitis B surface antibody positive recipients. © 2013 Baishideng Publishing Group Co., Limited. All rights reserved.

Varotsos C.A.,National and Kapodistrian University of Athens
Theoretical and Applied Climatology | Year: 2013

The El Niño-Southern Oscillation (ENSO)-like variability of various parameters and indices (e.g. sea surface temperature (SST)) is explored, by employing the last six decades of data on a global scale. We found that the ENSO signal in the SST field extends over tropics and subtropics, becoming maximum around 30° N and 30° S. The pronounced ENSO signal in the SST is observed over the southern tropics and subtropics. Additionally, the investigation of regional links between the Pacific Decadal Oscillation and SST revealed a new regional link, which extends in the tropical southern Pacific Ocean, where the effects of a long-lived pattern of SST are taking place. Furthermore, very strong SST-like surface temperature behaviour is observed over the equatorial Indian Ocean, being a new input to the assessment of "dangerous anthropogenic interference". The above-mentioned findings could be employed to the advanced modelling development to improve climate change projections. © 2012 Springer-Verlag Wien.

Alevizaki M.,National and Kapodistrian University of Athens
Thyroid Research | Year: 2013

Hyperparathyroidism occurs in 20-30% of MEN2A syndrome patients. It is usually associated with mild disease and is frequently asymptomatic, especially in younger age. There is genotype/phenotype association and PHP is usually associated with codon 634 mutations; however association with more rare mutations has also been reported. The pathology of the parathyroid glands includes hyperplasia, adenoma or a combination of the two. The optimal surgical management of this entity has not been defined yet. © 2013Alevizaki; licensee BioMed Central Ltd.

Duntas L.H.,National and Kapodistrian University of Athens
Thyroid Research | Year: 2013

Background: The American Thyroid Association (ATA) and more recently the European Thyroid Association (ETA) Guidelines on diagnosis and treatment of medullary thyroid carcinoma (MTC) have provided an excellent tool which was formerly lacking in the field of management of MTC. However, some relevant clinical questions, as the use of somatostatin analogues in the treatment of MTC and the management of pregnant patients with MTC, which were recommended in the guidelines, have been lately extensively revised. Moreover the current issue whether GLP-1 (a glucagon-like peptide-1) analogue is associated with MTC has only superficially been analyzed. Methods. Publications have been retrieved in MEDLINE at Pubmed (there is no fix date retrospectively) up to October 2012 using the terms medullary thyroid carcinoma, somatostatin, pregnancy and incretins. The recommendations made by ATA and ETA were considered. Conclusions: There are no data supporting the application of somatostatin analogues in the treatment of MTC, while thyroid cancer during or after pregnancy has no impact on the prognosis of disease or on the outcome of pregnancy. However, women with MEN 2 should be carefully controlled before any planned or during any unplanned pregnancy. In contrast to animal studies, there are no consistent human data supporting a stimulatory effect of GLP-1 receptor activation by liraglutide, an incretin mimetic, on calcitonin levels, though establishment of a registry and further studies are required to exclude any association between GLP-1 analogue and MTC. © 2013 Duntas; licensee BioMed Central Ltd.

Oikonomou K.,Ionian University | Stavrakakis I.,National and Kapodistrian University of Athens
IEEE Journal on Selected Areas in Communications | Year: 2010

Service placement is a key problem in communication networks as it determines how efficiently the user service demands are supported. This problem has been traditionally approached through the formulation and resolution of large optimization problems requiring global knowledge and a continuous recalculation of the solution in case of network changes. Such approaches are not suitable for large-scale and dynamic network environments. In this paper, the problem of determining the optimal location of a service facility is revisited and addressed in a way that is both scalable and deals inherently with network dynamicity. In particular, service migration which enables service facilities to move between neighbor nodes towards more communication cost-effective positions, is based on local information. The migration policies proposed in this work are analytically shown to be capable of moving a service facility between neighbor nodes in a way that the cost of service provision is reduced and - under certain conditions - the service facility reaches the optimal (cost minimizing) location, and locks in there as long as the environment does not change; as network conditions change, the migration process is automatically resumed, thus, naturally responding to network dynamicity under certain conditions. The analytical findings of this work are also supported by simulation results that shed some additional light on the behavior and effectiveness of the proposed policies. © 2010 IEEE.

Vlachantoni I.T.,National and Kapodistrian University of Athens
Sleep medicine reviews | Year: 2013

Obstructive sleep apnea (OSA) is associated with increased arterial stiffness, a cumulative indicator of arterial health. Continuous positive airway pressure (CPAP) is the gold standard treatment for OSA. We conducted a meta-analysis of the available literature investigating the effect of CPAP on arterial stiffness in patients with OSA. Fifteen articles (n = 615 patients) assessing indices of arterial stiffness were identified. Five different meta-analyses were performed assessing: a) all indices of arterial stiffness, b) augmentation index (AIx), c) all pulse wave velocities (PWV), d) brachial-ankle PWV and e) carotid-femoral PWV. Pooled standardized mean differences (SMDs) and weighted mean differences (WMDs) were appropriately calculated through fixed or random effects models after assessing between-study heterogeneity. A significant improvement of all indices of arterial stiffness was observed after CPAP treatment (SMD = -0.74; 95%CI: -1.08 to -0.41). AIx and PWVs were also significantly improved (WMD = -4.86; 95%CI: -7.31 to -2.41 and WMD = -0.87; 95%CI: -0.98 to -0.77, respectively), as well as brachial-ankle PWV and carotid-femoral PWV (WMD = -0.86; 95%CI: -0.97 to -0.75 and WMD = -1.21; 95%CI:-1.92 to -0.50, respectively). Neither the proportion of compliant patients nor the duration of CPAP use altered the effect of arterial stiffness reduction after CPAP treatment. In conclusion, our meta-analyses showed significant improvements in all indices of arterial stiffness after CPAP treatment in patients with OSA. As clinical use of arterial stiffness is growing in popularity, the efficacy of this useful tool in assessing cardiovascular risk reduction among patients with OSA treated with CPAP needs to be further explored. Copyright © 2012 Elsevier Ltd. All rights reserved.

Terrovitis J.V.,National and Kapodistrian University of Athens | Smith R.R.,Cedars Sinai Medical Center | Marban E.,Cedars Sinai Medical Center
Circulation Research | Year: 2010

Myocardial regeneration using stem and progenitor cell transplantation in the injured heart has recently become a major goal in the treatment of cardiac disease. Experimental studies and clinical applications have generally been encouraging, although the functional benefits that have been attained clinically are modest and inconsistent. Low cell retention and engraftment after myocardial delivery is a key factor limiting the successful application of cell therapy, irrespective of the type of cell or the delivery method. To improve engraftment, accurate methods for tracking cell fate and quantifying cell survival need to be applied. Several laboratory techniques (histological methods, real-time quantitative polymerase chain reaction, radiolabeling) have provided invaluable information about cell engraftment. In vivo imaging (nuclear medicine modalities, bioluminescence, and MRI) has the potential to provide quantitative information noninvasively, enabling longitudinal assessment of cell fate. In the present review, we present several available methods for assessing cell engraftment, and we critically discuss their strengths and limitations. In addition to providing insights about the mechanisms mediating cell loss after transplantation, these methods can evaluate techniques for augmenting engraftment, such as tissue engineering approaches, preconditioning, and genetic modification, allowing optimization of cell therapies. © 2010 American Heart Association, Inc.

Sfetsos K.,University of Surrey | Sfetsos K.,National and Kapodistrian University of Athens
Nuclear Physics B | Year: 2014

We derive two new classes of integrable theories interpolating between exact CFT WZW or gauged WZW models and non-Abelian T-duals of principal chiral models or geometric coset models. They are naturally constructed by gauging symmetries of integrable models. Our analysis implies that non-Abelian T-duality preserves integrability and suggests a novel way to understand the global properties of the corresponding backgrounds. © 2014 The Author.

Malecki P.H.,Polish Academy of Sciences | Vorgias C.E.,National and Kapodistrian University of Athens | Petoukhov M.V.,German Electron Synchrotron | Svergun D.I.,German Electron Synchrotron | Rypniewski W.,Polish Academy of Sciences
Acta Crystallographica Section D: Biological Crystallography | Year: 2014

The four-domain structure of chitinase 60 from Moritella marina (MmChi60) is outstanding in its complexity. Many glycoside hydrolases, such as chitinases and cellulases, have multi-domain structures, but only a few have been solved. The flexibility of the hinge regions between the domains apparently makes these proteins difficult to crystallize. The analysis of an active-site mutant of MmChi60 in an unliganded form and in complex with the substrates NAG4 and NAG5 revealed significant differences in the substrate-binding site compared with the previously determined complexes of most studied chitinases. A SAXS experiment demonstrated that in addition to the elongated state found in the crystal, the protein can adapt other conformations in solution ranging from fully extended to compact. © 2014 International Union of Crystallography.

Papatheodoridis G.V.,National and Kapodistrian University of Athens | Tsochatzis E.,University College London | Hardtke S.,Hannover Medical School | Wedemeyer H.,Hannover Medical School
Liver International | Year: 2014

Background & Aims: Despite the availability of effective therapies for hepatitis B (HBV) and C virus (HCV), only a minority of these patients receive treatment. We systematically reviewed published data on barriers to management for chronic HBV/HCV patients in Europe. Methods: Literature search to identify studies including adult patients with chronic HBV/HCV infection from European countries and data on barriers to treatment. Results: Twenty-five studies including 6253 chronic HBV and 19 014 HCV patients were identified, of which only two were from Eastern Europe. The mean rate of no treatment in HBV patients was 42% being higher in North-Western European countries than Italy (56% vs. 39%, P < 0.001). Immigrants represented the most common barrier to HBV treatment. The mean rate of no treatment in HCV RNA-positive patients was 57%, being highest in Romania (89%), intermediate in France (79%) and lower though still high in other European countries (52%, P < 0.001). The predominant barriers to HCV treatment were lack of financial resources in Romania and direct/indirect limitations of interferon-alfa and/or parenteral drug and alcohol abuse in other countries. The mean rate of no treatment was highest in HCV RNA-positive parenteral drug users (72%) and intermediate in those with HCV-HIV co-infection (64%). Conclusions: A substantial proportion of diagnosed chronic HBV and the majority of diagnosed HCV patients remain untreated. The rates and most importantly the reasons of barriers to treatment in chronic HBV/HCV patients vary widely among European countries supporting the need for country-specific national strategies, resource allocation and implementation of global management policies. © 2014 John Wiley & Sons A/S.

Stepien K.,University of Warsaw | Gazeas K.,National and Kapodistrian University of Athens | Gazeas K.,European Space Agency
Acta Astronomica | Year: 2012

We present a study on low-mass contact binaries (LMCB) with orbital periods shorter than 0.3 days and total mass lower than about 1.4 M ⊙. We show that such systems have a long pre-contact phase, which lasts for 8-9 Gyrs, while the contact phase takes only about 0.8 Gyr, which is rather a short fraction of the total life. With low mass transfer rate during contact, moderate mass ratios prevail in LMCBs since they do not have enough time to reach extreme mass ratios often observed in higher mass binaries. During the whole evolution both components of LMCBs remain within the MS band. The evolution of cool contact binaries toward merging is controlled by the interplay between the evolutionary expansion of the less massive component resulting in the mass transfer to the more massive component and the angular momentum loss from the system by the magnetized wind. In LMCB the angular momentum loss prevails. As a result, the orbital period systematically decreases until the binary overflows the outer critical Roche surface and the components merge into a single fast rotating star of a solar type surrounded by a remnant disk carrying excess angular momentum. The disk can be a place of planet formation with the age substantially lower than the age of a host star. The calculated theoretical tracks show good agreement with the physical properties of LMCB from the available observations. Estimates of the frequency of occurrence of LMCB and the merger formation rate indicate that about 40 LMCBs and about 100 low mass merger products is expected to exist within 100 pc from the Sun.

Alexopoulou A.,National and Kapodistrian University of Athens | Karayiannis P.,University of Nicosia
Annals of Gastroenterology | Year: 2015

The development of protease inhibitors (PIs) such as telaprevir and boceprevir constitutes a milestone in chronic hepatitis C antiviral treatment since it has achieved sustained virological response (SVR) rates of up to 75% in naïve and 29-88% in treatment-experienced patients with genotype 1 infection. Both require combination treatment with pegylated interferon (PEG-IFN) plus ribavirin (RBV) as PI monotherapy results in resistant mutations. New direct acting antiviral agents (DAAs) have recently been approved or their approval is imminent. Simeprevir administered orally as one pill per day in combination with PEG-IFN/RBV will be the next PI to be approved. The SVR rates at about 72-80% for treatment-naïve patients are not a major improvement over telaprevir or boceprevir. However, this treble combination has fewer side effects and drug-drug interactions and most patients undergo shorter treatment duration (24 months) due to earlier treatment responses. Sofosbuvir is the first available once-daily NS5B polymerase inhibitor which has been approved in combination with PEG-IFN/RBV for just 12 weeks with 89% SVR in treatment-naïve patients with genotype 1 infection and 83-100% in treatment-experienced patients with genotypes 2/3. The current review focuses on the recent rapid and continuous developments in the management of chronic HCV infection with DAAs in combination with PEG-IFN/RBV. © 2015 Hellenic Society of Gastroenterology.

Kaditis A.,National and Kapodistrian University of Athens | Kheirandish-Gozal L.,University of Chicago | Gozal D.,University of Chicago
Sleep Medicine Reviews | Year: 2016

Overnight polysomnography is the gold standard tool for the diagnosis of obstructive sleep apnea syndrome (OSAS) in habitually snoring children, but it is expensive and not always available. Nocturnal oximetry has been proposed as an abbreviated and low-cost testing modality for the diagnosis of OSAS. In this systematic review, 25 original articles were evaluated to: (i) summarize reference values of nocturnal oximetry parameters in healthy children; (ii) identify abnormal oximetry patterns that predict OSAS in habitually snoring children; (iii) delineate abnormalities in oximetry that can predict responses to treatment interventions for OSAS and potential complications. Nocturnal SpO2 drops <90%, more than two clusters of desaturation events (≥4%) and oxyhemoglobin desaturation (≥4%) index (ODI4) >2.2 episodes/h are unusual in children without OSAS. At least three clusters of desaturation events, and at least three SpO2 drops below 90% in a nocturnal oximetry recording are indicative of moderate-to-severe OSAS. An ODI4 >2 episodes/h combined with OSAS symptoms also exhibits high positive predictive value for apnea-hypopnea index >1 episode/h. Children without clusters of desaturation events have low risk of major respiratory complications following adenotonsillectomy. Thus, nocturnal oximetry emerges as a valuable tool that can facilitate treatment decisions when polysomnography is not available. © 2015 Elsevier Ltd.

Vassilopoulos D.,National and Kapodistrian University of Athens | Calabrese L.H.,Cleveland Clinic
Nature Reviews Rheumatology | Year: 2012

Despite the major advances towards better prevention and treatment of hepatitis B virus (HBV) and hepatitis C virus (HCV) infections, these two chronic infections still account for ĝ̂1/4500 million infected people and 1 million deaths per year worldwide. Rheumatologists are frequently encountering patients with rheumatic disease who have co-existing HBV or HCV infection in daily clinical practice. Moreover, over the past decade, a number of studies have shown an increased risk of HBV reactivation and liver-related complications in HBV-infected patients treated with biologic agents (especially anti-TNF therapies). In this Review, the basic viral characteristics of HBV and HCV, as well as the natural course of chronic HBV and HCV infection, are outlined. Furthermore, a rational clinical approach for diagnosis and treatment of these comorbid conditions in the context of rheumatic disease is presented. © 2012 Macmillan Publishers Limited.

Mitropoulos D.,National and Kapodistrian University of Athens | Artibani W.,University of Verona | Graefen M.,University of Hamburg | Remzi M.,Landesklinikum Korneuburg | And 2 more authors.
European Urology | Year: 2012

Context: The incidence of postoperative complications is still the most frequently used surrogate marker of quality in surgery, but no standard guidelines or criteria exist for reporting surgical complications in the area of urology. Objective: To review the available reporting systems used for urologic surgical complications, to establish a possible change in attitude towards reporting of complications using standardised systems, to assess systematically the Clavien-Dindo system when used for the reporting of complications related to urologic surgical procedures, to identify shortcomings in reporting complications, and to propose recommendations for the development and implementation of future reporting systems that are focused on patient-centred outcomes. Evidence acquisition: Standardised systems for reporting and classification of surgical complications were identified through a systematic review of the literature. To establish a possible change in attitude towards reporting of complications related to urologic procedures, we performed a systematic literature search of all papers reporting complications after urologic surgery published in European Urology, Journal of Urology, Urology, BJU International, and World Journal of Urology in 1999-2000 and 2009-2010. Data identification for the systematic assessment of the Clavien-Dindo system currently used for the reporting of complications related to urologic surgical interventions involved a Medline/Embase search and the search engines of individual urologic journals and publishers using Clavien, urology, and complications as keywords. All selected papers were full-text retrieved and assessed; analysis was done based on structured forms. Evidence synthesis: The systematic review of the literature for standardised systems used for reporting and classification of surgical complications revealed five such systems. As far as the attitude of urologists towards reporting of complications, a shift could be seen in the number of studies using most of the Martin criteria, as well as in the number of studies using either standardised criteria or the Clavien-Dindo system. The latter system was not properly used in 72 papers (35.3%). Conclusions: Uniformed reporting of complications after urologic procedures will aid all those involved in patient care and scientific publishing (authors, reviewers, and editors). It will also contribute to the improvement of the scientific quality of papers published in the field of urologic surgery. When reporting the outcomes of urologic procedures, the committee proposes a series of quality criteria. © 2011 European Association of Urology. Published by Elsevier B.V. All rights reserved.

Lambrinoudaki I.,National and Kapodistrian University of Athens
Current diabetes reviews | Year: 2010

Constant advances in gene mapping technology have allowed research to focus from rare monogenic disorders on common complex diseases involving multiple susceptibility genes-environment interactions. Gestational diabetes mellitus (GDM) is a heterogeneous pathogenic condition affecting 2-5% of all pregnant women during pregnancy. GDM is considered to result when genetic predisposition is triggered by increased insulin resistance during pregnancy leading to what seems to be one of the primary characteristics of GDM, the pancreatic b-cell impairment. Genetic predisposition to GDM has been suggested given the occurrence of the disease within family members. Furthermore, GDM is reported to be often present in women with maturity onset diabetes of the young (MODY) gene mutations. In addition, candidate susceptibility gene variants have been suggested to increase the risk of GDM. These genes include glucokinase (GCK), HLA antigens, insulin receptor (INSR), insulin-like growth factor-2 (IGF2), HNF4A, insulin gene (INS-VNTR), plasminogen activator inhibitor 1 (PAI-1), potassium inwardly rectifying channel subfamily J, member 11 (KCNJ11), hepatocyte nuclear factor-4a (HNF4A). Identification of the possible underlying genetic factors of GDM would eventually enrich our knowledge on the pathophysiologic mechanism of the disease and contribute to the individualization of both prevention and treatment of complications for the mother and fetus. However, so far, little is known about the genetic basis of GDM and its potential clinical significance. This review focuses on possible gestational diabetes mellitus susceptibility genes and their association with the disease incidence and severity as well as the pregnancy outcome and the response to treatment.

Duntas L.H.,National and Kapodistrian University of Athens | Benvenga S.,Messina University
Endocrine | Year: 2015

This review aims to illustrate the importance of selenium (Se) for maintenance of overall health, especially for the thyroid, immunity, and homeostasis. Furthermore, it outlines the role of Se in reproduction and in virology and discusses the effects of Se supplementation in critical illness. The multifaceted aspects of this essential nutrient have attracted worldwide clinical and research interest in the last few decades. Se exerts its activity in the form of the aminoacid selenocysteine incorporated in selenoproteins. The impact of Se administration should be considered in relation to its apparent U shaped effects, i.e., exhibiting major advantages in Se-deficient individuals but specific health risks in those with Se excess. Addition of selenium to the administration of levothyroxine may be useful in patients with low Se intake and with mild-form or early-stage Hashimoto’s thyroiditis (HT). Serum Se concentration (possibly also at tissue level) decreases in inflammatory conditions and may vary with the severity and duration of the inflammatory process. In such cases, the effect of Se supplementation seems to be useful and rational. Meanwhile, Se’s ability to improve the activity of T cells and the cytotoxicity of natural killer cells could render it effective in viral disease. However, the evidence, and this should be stressed, is at present conflicting as to whether Se supplementation is of benefit in patients with HT, though there are indications that it is advantageous in cases of mild/moderate Graves’ Orbitopathy. The role of Se in type 2 diabetes mellitus (T2DM) is ambiguous, driven by both Se intake and serum levels. The evidence that insulin and glycaemia influence the transport and activity of Se, via regulatory activity on selenoproteins, and that high serum Se may have a diabetogenic effect suggests a ‘Janus-effect’ of Se in T2DM. Though the evidence is not as yet clear-cut, the organic form (selenomethionine), due to its pharmacokinetics, is likely to be more advantageous in long-term prevention, and supplementation efforts, while the inorganic form (sodium selenite) has proven effective in an acute, e.g., sepsis, clinical setting. Recent data indicate that functional selenoprotein single-nucleotide polymorphisms (SNPs) may interfere with Se utilization and effectiveness. © 2014, Springer Science+Business Media New York.

Motti-Stefanidi F.,National and Kapodistrian University of Athens | Asendorpf J.B.,Humboldt University of Berlin | Masten A.S.,University of Minnesota
Development and Psychopathology | Year: 2012

This study examined growth patterns in adaptation of immigrant youth from a risk and resilience perspective. Students from first- and second-generation immigrant families living in Greece and their nonimmigrant classmates (N = 1,057) were assessed over the first 3 years of secondary school (ages 13-15). Three-level hierarchical linear models were used to disentangle individual and classroom-level effects on initial level and change in academic achievement, conduct, peer popularity, and psychological well-being. At the individual level, adaptation was more related to self-efficacy and parental school involvement (resources) than immigrant status and social adversity (risks). Only for academic achievement did risks explain variance when resources were controlled. Parental school involvement moderated the effect of immigrant status for initial level and growth in achievement. For all students, achievement and conduct worsened over time. At the classroom level, socioeconomic and ethnic composition of the classroom moderated the effects of self-efficacy and immigrant status on academic achievement and peer popularity, respectively. Second-generation immigrants were more popular than first-generation immigrants, but showed a larger decrease over time in school achievement. Results support a developmental, differentiated, and contextualized approach to the study of immigrant youth adaptation. © 2012 Cambridge University Press.

Simserides C.,National and Kapodistrian University of Athens
Chemical Physics | Year: 2014

A systematic study of carrier transfer along DNA dimers, trimers and polymers including poly(dG)-poly(dC), poly(dA)-poly(dT), GCGCGC..., ATATAT... is presented allowing to determine the spatiotemporal evolution of electrons or holes along a N base-pair DNA segment. Physical quantities are defined including maximum transfer percentage p and pure maximum transfer rate pT when a period T is defined; pure mean transfer rate k and speed u=kd, where d is the charge transfer distance. The inverse decay length β for the exponential fit k=k0exp(-βd) and the exponent η for the power-law fit k=k0′N-η are computed. β≈ 0.2-2 Å-1, k0 is usually 10-2-10-1 PHz, generally ≈10-4-10 PHz. η≈1.7-17, k0′ is usually 10-2-10-1 PHz, generally ≈10-4-10 3 PHz. The results are compared with theoretical and experimental works. This method allows to assess the extent at which a specific DNA segment can serve for charge transfer. © 2014 Elsevier B.V. All rights reserved.

Meinhold G.,University of Gottingen | Kostopoulos D.K.,National and Kapodistrian University of Athens
Tectonophysics | Year: 2013

The Circum-Rhodope Belt (CRB) sensu stricto comprises low-grade metamorphosed Triassic and Jurassic sedimentary rocks fringing the high-grade metamorphic rocks of the Serbo-Macedonian and Rhodope massifs in northern Greece. Main outcrops occur in the easternmost part of the Vardar suture zone in the Chalkidiki peninsula (Melissochori Formation; formerly Svoula flysch) and in Thrace (Makri unit and Melia Formation). The tectonostratigraphic relationship between the CRB and the high-grade metamorphics has been the subject of long discussions. Older interpretations maintain that the CRB represents the original Mesozoic stratigraphic cover of the Serbo-Macedonian crystalline basement, whereas later revisions propose the existence of two distinct greenschist-facies Mesozoic metasedimentary units: an eastern unit related to the development of a Jurassic black shale basin north of the Rhodope, and a western unit related to the development of an olistostromic flysch in the Cretaceous. Here we present a critical re-evaluation of the CRB with regard to its age, provenance, and tectonic setting based on novel geochemical and isotopic data.The Makri unit and the Melissochori Formation belong to the CRB proper and were deposited in proximity to Carboniferous-Early Permian igneous basement rocks (Pelagonia / Strandja / Thracia Terrane) in latest Triassic and Jurassic times, as shown by a prominent detrital zircon age population of 350-290. Ma. By contrast, the Melia Formation is unrelated to the CRB and was deposited in a foreland basin in front of a metamorphic nappe pile with Rhodopean affinities in the early Cretaceous, as shown by a prominent detrital zircon age population of 315-285. Ma and xenocrysts of ~. 550. Ma and ~. 450. Ma. Thus, the commonly accepted CRB concepts have to be revisited. All units have been tectonically juxtaposed to their present location during Balkan and Alpine orogenic processes. © 2012 Elsevier B.V.

Nitrate (NO3) is one of the most common contaminants in aquatic environments and groundwater. Nitrate concentrations and environmental isotope data (d15N-NO3 and d18O-NO3) from groundwater of Asopos basin, which has different land-use types, i.e., a large number of industries (e.g., textile, metal processing, food, fertilizers, paint), urban and agricultural areas and livestock breeding facilities, were analyzed to identify the nitrate sources of water contamination and N-biogeochemical transformations. A Bayesian isotope mixing model (SIAR) and multivariate statistical analysis of hydrochemical data were used to estimate the proportional contribution of different NO3 sources and to identify the dominant factors controlling the nitrate content of the groundwater in the region. The comparison of SIAR and Principal Component Analysis showed that wastes originating from urban and industrial zones of the basin are mainly responsible for nitrate contamination of groundwater in these areas. Agricultural fertilizers and manure likely contribute to groundwater contamination away from urban fabric and industrial land-use areas. Soil contribution to nitrate contamination due to organic matter is higher in the south-western part of the area far from the industries and the urban settlements. The present study aims to highlight the use of environmental isotopes combined with multivariate statistical analysis in locating sources of nitrate contamination in groundwater leading to a more effective planning of environmental measures and remediation strategies in river basins and water bodies as defined by the European Water Frame Directive (Directive 2000/60/EC). © 2015 Elsevier B.V.

Duntas L.H.,National and Kapodistrian University of Athens
Journal of Thyroid Research | Year: 2012

Graves' disease (GD) and ophthalmopathy (GO) are organ-specific autoimmune-inflammatory disorders characterized by a complex pathogenesis. The inflammatory process is dominated by an imbalance of the antioxidant-oxidant mechanism, increased production of radical oxygen species (ROS), and cytokines which sustain the autoimmune process and perpetuate the disease. Recently, selenium, which is a powerful antioxidant, has been successfully applied in patients with mild GO, slowing the progression of disease, decreasing the clinical activity score, and appreciably improving the quality of life. The mechanisms of selenium action are variable. The aim of this review is to summarize the actions of selenium in GD and GO. Selenium as selenocysteine is incorporated in selenoproteins, such as glutathione peroxidase which catalyzes the degradation of hydrogen peroxide and lipid hydroperoxide that are increasingly produced in hyperthyroidism. Moreover, selenium decreases the formation of proinflammatory cytokines, while it contributes, in synergy with antithyroid drugs, to stabilization of the autoimmune process in GD and alleviation of GO. It is now to be clarified whether enforced nutritional supplementation has the same results and whether prolonging selenium administration may have an impact on the prevention of disease. © 2012 Leonidas H. Duntas.

Bonovas S.,National and Kapodistrian University of Athens
Drugs | Year: 2014

3-Hydroxy-3-methylglutaryl-coenzyme A reductase inhibitors (statins) are currently among the most commonly prescribed pharmaceutical agents worldwide. Apart from their well-established therapeutic value in cardiovascular disease, there is a long-standing debate on their potential association with cancer. To obtain and discuss the existing clinical evidence, an overview of meta-analysis articles addressing this issue was carried out. As of today, the accumulated evidence does not support the hypothesis that statins affect the risk of developing cancer, when they are taken at low doses for managing hypercholesterolaemia. However, current data cannot exclude an increased cancer risk in elderly patients associated with hydrophilic statin use, or decreases in the risks of certain cancers, such as gastric, oesophageal, liver, colorectal and advanced/aggressive prostate cancer. On the other hand, some recent observational studies have provided evidence that statins might be useful in modifying the prognosis of patients diagnosed with malignancy. Until a definitive benefit is demonstrated in randomized controlled trials, statins cannot be recommended either for cancer prevention or for modifying cancer-related outcomes. Further research is warranted to clarify the potential role(s) of statins in the prevention and treatment of cancer. © 2014 Springer International Publishing Switzerland.

Obeso J.A.,University of Navarra | Obeso J.A.,CIBER ISCIII | Rodriguez-Oroz M.C.,CIBER ISCIII | Rodriguez-Oroz M.C.,University Hospital Donostia | And 4 more authors.
The Lancet | Year: 2014

Summary The basal ganglia were originally thought to be associated purely with motor control. However, dysfunction and pathology of different regions and circuits are now known to give rise to many clinical manifestations beyond the association of basal ganglia dysfunction with movement disorders. Moreover, disorders that were thought to be caused by dysfunction of the basal ganglia only, such as Parkinson's disease and Huntington's disease, have diverse abnormalities distributed not only in the brain but also in the peripheral and autonomic nervous systems; this knowledge poses new questions and challenges. We discuss advances and the unanswered questions, and ways in which progress might be made. © 2014 Elsevier Ltd.

Papadogeorgakis N.,National and Kapodistrian University of Athens
British Journal of Oral and Maxillofacial Surgery | Year: 2011

We present our experience of 156 patients with parotid pleomorphic adenomas who were treated from 1995 to 2009 by partial superficial parotidectomy. In each case the main trunk of the facial nerve was identified and dissected. Only the division of the nerve adjacent to the tumour was dissected, and only the parotid tissue surrounding the tumour was excised. The results were satisfactory, as no patient developed permanent partial or total facial nerve paralysis, and transient paresis was noticed in only 23 patients (15%). Only one tumour recurred, and Frey syndrome developed in only 6 patients (4%). Enucleation was required in 55 patients (35%) because the tumour was so close to the branches of the facial nerve. Partial superficial parotidectomy is a safe treatment for parotid pleomorphic adenomas with relatively few postoperative complications. When it is done by experienced surgeons no permanent deficits are likely, it has low rates of recurrence, and gives excellent aesthetic results. © 2010 British Association of Oral and Maxillofacial Surgeons.

This paper investigates the politeness strategies and mitigation devices used by native and non-native speakers (advanced learners) of Greek when refusing an invitation from an intimate and their consequences for the expression of politeness. Furthermore, it examines whether length of residence or intensity of interaction with native speakers affect non-native speakers' performance. The data are drawn from role plays performed by native speakers and non-native speakers of two different groups: one with extended length of residence but limited opportunities for social interaction with native speakers and one with less extended length of residence but considerably more frequent opportunities for social interaction. On the basis of these data, it is argued that with regard to the speech act of declining an invitation from a friend, length of residence can be an insufficient measure whereas intensity of interaction can guarantee better results as regards pragmatic appropriateness and politeness. The significant deviations observed between native speakers and non-native speakers with limited opportunities for intimate interaction are attributed to the fact that the latter being economic migrants, who suffer from social seclusion, cannot rely on length of residence alone, in order to acquire sociocultural norms and develop pragmatic ability in the use of speech acts like the one investigated here. This fact combined with the finding that both groups of non-native speakers displayed an underdeveloped pragmatic ability in relation to mitigation devices, such as lexical/phrasal downgraders highlights the need for pedagogical intervention which aims at providing learners with metapragmatic information and meaningful opportunities for interaction that may promote their pragmatic development. © 2010 Elsevier B.V.

Royden L.H.,Massachusetts Institute of Technology | Papanikolaou D.J.,National and Kapodistrian University of Athens
Geochemistry, Geophysics, Geosystems | Year: 2011

The Hellenic subduction zone displays well-defined temporal and spatial variations in subduction rate and offers an excellent natural laboratory for studying the interaction among slab buoyancy, subduction rate, and tectonic deformation. In space, the active Hellenic subduction front is dextrally offset by 100-120 km across the Kephalonia Transform Zone, coinciding with the junction of a slowly subducting Adriatic continental lithosphere in the north (5-10 mm/yr) and a rapidly subducting Ionian oceanic lithosphere in the south (∼35 mm/yr). Subduction rates can be shown to have decreased from late Eocene time onward, reaching 5-12 mm/yr by late Miocene time, before increasing again along the southern portion of the subduction system. Geodynamic modeling demonstrates that the differing rates of subduction and the resultant trench offset arise naturally from subduction of oceanic (Pindos) lithosphere until late Eocene time, followed by subduction of a broad tract of continental or transitional lithosphere (Hellenic external carbonate platform) and then by Miocene entry of high-density oceanic (Ionian) lithosphere into the southern Hellenic trench. Model results yield an initiation age for the Kephalonia Transform of 6-8 Ma, in good agreement with observations. Consistency between geodynamic model results and geologic observations suggest that the middle Miocene and younger deformation of the Hellenic upper plate, including formation of the Central Hellenic Shear Zone, can be quantitatively understood as the result of spatial variations in the buoyancy of the subducting slab. Using this assumption, we make late Eocene, middle Miocene, and Pliocene reconstructions of the Hellenic system that include quantitative constraints from subduction modeling and geologic constraints on the timing and mode of upper plate deformation. Copyright 2011 by the American Geophysical Union.

Downey R.G.,The New School | Thilikos D.M.,National and Kapodistrian University of Athens
Computer Science Review | Year: 2011

One approach to confronting computational hardness is to try to understand the contribution of various parameters to the running time of algorithms and the complexity of computational tasks. Almost no computational tasks in real life are specified by their size alone. It is not hard to imagine that some parameters contribute more intractability than others and it seems reasonable to develop a theory of computational complexity which seeks to exploit this fact. Such a theory should be able to address the needs of practitioners in algorithmics. The last twenty years have seen the development of such a theory. This theory has a large number of successes in terms of a rich collection of algorithmic techniques, both practical and theoretical, and a fine-grained intractability theory. Whilst the theory has been widely used in a number of areas of applications including computational biology, linguistics, VLSI design, learning theory and many others, knowledge of the area is highly varied. We hope that this article will show the basic theory and point at the wide array of techniques available. Naturally the treatment is condensed, and the reader who wants more should go to the texts of Downey and Fellows (1999) [2], Flum and Grohe (2006) [59], Niedermeier (2006) [28], and the upcoming undergraduate text (Downey and Fellows 2012) [278]. © 2011 Elsevier Inc.

Sfetsos K.,National and Kapodistrian University of Athens | Siampos K.,University of Mons
Nuclear Physics B | Year: 2014

We study what we call the all-loop anisotropic bosonized Thirring σ-model. This interpolates between the WZW model and the non-Abelian T-dual of the principal chiral model for a simple group. It has an invariance involving the inversion of the matrix parameterizing the coupling constants. We compute the general renormalization group flow equations which assume a remarkably simple form and derive its properties. For symmetric couplings, they consistently truncate to previous results in the literature. One of the examples we provide gives rise to a first order system of differential equations interpolating between the Lagrange and the Darboux-Halphen integrable systems. © 2014 The Authors.

Chadio S.,National and Kapodistrian University of Athens | Kotsampasi B.,Animal Research Institute
Journal of Developmental Origins of Health and Disease | Year: 2014

Accumulating evidence suggest that the concept of programming can also be applied to reproductive development and function, representing an ever expanding research area. Recently issues such as peri-or even preconceptional nutrition, transgenerational effects and underlying mechanisms have received considerable attention. The present chapter presents the existed evidence and reviews the available data from numerous animal and human studies on the effects of early life nutritional environment on adult reproductive function. Specific outcomes depend on the severity, duration and stage of development when nutritional perturbations are imposed, while sex-specific effects are also manifested. Apart from undernutrition, effects of relative overnutrition as well as the complex interactions between pre-and postnatal nutrition is of high importance, especially in the context of our days obesity epidemic. Mechanisms underlying reproductive programming are yet unclear, but may include a role for epigenetic modifications. Epigenetic modulation of critical genes involved in the control of reproductive function and potential intergenerational effects represent an exciting area of interdisciplinary research toward the development of new nutritional approaches during pre-and postnatal periods to ensure reproductive health in later life.

Mavragani C.P.,National and Kapodistrian University of Athens | Crow M.K.,Mary Kirkland Center for Lupus Research
Journal of Autoimmunity | Year: 2010

Sjogren's syndrome (SS), a chronic autoimmune systemic disease affecting middle aged women, is characterized by lymphocytic infiltration of the salivary and lachrymal glands resulting in dry eyes and dry mouth. Recent advances have revealed a major role for activation of the type I interferon (IFN) pathway in the pathogenesis of the syndrome, as evidenced by the increased circulating type I IFN activity and an IFN "signature" in peripheral blood mononuclear cells (PBMC) and minor salivary gland (MSG) biopsies from these patients. Polymorphisms in genes involved in the IFNα pathway, such as IRF5 and STAT4, have been found to be associated with disease susceptibility. While the initial triggers of the innate immune response in SS remain elusive, preliminary evidence supports the role of inappropriately expressed endogenous LINE-1 (L1) retroelements as potential triggers of type I IFN activation in SS, possibly through Toll-like receptor (TLR) dependent or independent pathways. Proteins of the methylation machinery and the APOBEC family of cytidine deaminases are coordinately overexpressed, suggesting that those proteins might contribute to regulation of the inappropriately expressed L1 endogenous retroelements in SS. Given the apparent central role of IFNα in the pathogenesis of SS, blockade of this cytokine may be a rational therapeutic approach. In the current review we summarize the current evidence regarding the potential triggers of type I IFN activation as well as the data supporting genetic and epigenetic regulation of the type I IFN system in SS. © 2010 Elsevier Ltd.

Itsios G.,University of Patras | Sfetsos K.,National and Kapodistrian University of Athens | Siampos K.,University of Mons
Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics | Year: 2014

We analyze the renormalization group flow in a recently constructed class of integrable σ-models which interpolate between WZW current algebra models and the non-Abelian T-duals of PCM for a simple group G. They are characterized by the integer level k of the current algebra, a deformation parameter λ and they exhibit a remarkable invariance involving the inversion of λ. We compute the β-function for λ to leading order in 1k. Based on agreement with previous results for the exact β-function of the non-Abelian bosonized Thirring model and matching global symmetries, we state that our integrable models are the resummed version (capturing all counterterms in perturbation theory) of the non-Abelian bosonized Thirring model for a simple group G. Finally, we present an analogous treatment in a simple example of a closely related class of models interpolating between gauged WZW coset CFTs and the non-Abelian T-duals of PCM for the coset G/H. © 2014 The Authors.

Eleftheriadis E.,National and Kapodistrian University of Athens
Journal of oral science | Year: 2010

Currently, in oral and maxillofacial surgery, there is a clinical need for efficient bone grafting materials, and various efforts are being made to improve materials used as bone substitutes to facilitate faster and denser bone regeneration. The purpose of this study was to evaluate in vivo the osteogenic potential of synthetic β-tricalcium phosphate in a hydroxyl sulphate matrix (β-TCP/HS) and human demineralized bone matrix (DBM) putty. Sixteen New Zealand White rabbits were used. In each animal, two bone defects (8 mm length × 3 mm width × 3 mm depth) were created in the left and right regions of the mandible, respectively. The defect on one side, chosen randomly, was filled with β-TCP/HS (group A) or DBM putty (group B), while the defect on the opposite side was left unfilled in order to serve as a control site. Two animals in each group were sacrificed at the end of the 1st, 3rd, 5th and 6th week after surgery, respectively, and the osteotomy sites were processed for histological evaluation. Our findings confirmed that β-TCP/HS and human DBM putty possess osteogenic activity and can support new bone formation, although at a slower rate than the spontaneous healing response, in rabbit mandibular osseous defects.

Oulis P.,National and Kapodistrian University of Athens
Philosophy, Ethics, and Humanities in Medicine | Year: 2014

Introduction: In his classic essay " The phenomenological approach to psychopathology", Karl Jaspers defended the irreducible reality of the " subjective" mental symptoms and stressed the pivotal role of empathy in their diagnostic assessment. However, Jaspers' account of the epistemological role of empathy in psychopathological diagnosis was far from clear: whereas at several places Jaspers claimed that empathy provides a direct access to patients' abnormal mental experiences, at other places he stressed that it did so only indirectly, through a whole battery of their observable clinical indicators. The aim of this paper is to reassess Jaspers' account of the epistemological role of empathy in psychopathological diagnosis .Methods: I examine thoroughly Jaspers' assertions on in the role of empathy in the diagnosis of " subjective" symptoms. Moreover, I explicate briefly the epistemological status of psychopathological diagnostic examination with the aid of the distinction between direct and indirect observation. Results: Diagnostic assessment of " subjective" mental symptoms involves necessarily indirect psychopathological observation. Jaspers' ambiguity is traced to his failure to distinguish clearly between direct and indirect psychopathological observation along with his excessive reliance on empathy. Relatedly, Jaspers' ambiguity is also traced to his conflation of the semantics with the epistemology of psychopathological concepts representing patients' " subjective" mental symptoms. These results apply also to contemporary phenomenological approaches to psychopathological diagnostic examination which maintain that patients' abnormal mental experiences are invariably expressed in their overt behavior. Conclusions: Jaspers was right in stressing that psychopathological concepts of subjective mental symptoms represent patients' genuine abnormal experiences irreducible to concepts representing their associated behavioral manifestations. Moreover, he was right in stressing the importance of the empathic 'second person' approach to patients' mental experiences. However, he failed to recognize unambiguously that the epistemological access to patients' mental symptoms, though enormously aided by empathy, remains mainly indirect and thus requires also a 'third person' approach to them. Overall then, clinical psychopathological examination requires both a 'second' and a 'third' person approach, as well as their judicious alternation during the diagnostic interview. Although focused on Jaspers' essay, my critical analysis is also highly relevant to contemporary psychopathological approaches aiming to overcome the serious limitations of currently prevailing systems of diagnostic criteria of mental disorders. © 2014 Oulis; licensee BioMed Central Ltd.

Iatrou I.,National and Kapodistrian University of Athens
Journal of oral science | Year: 2010

Odontomas represent the most common type of odontogenic jaw tumors among patients younger than 20 years of age. Clinically, they are often associated with eruption failure of adjacent permanent teeth, and are classified as compound and complex. The aim of the present retrospective study was to present the characteristics, treatment approach and outcome of odontomas in Greek children, over a ten-year period. Twenty six patients, 2 to 14 years of age (mean 9.3 years), with odontomas treated during the years 1999-2008 at the Department of Oral & Maxillofacial Surgery of a Children's Hospital, were included in the study. Data from patients' files were retrieved and they were recalled for review. Odontomas were equally distributed in the maxilla and mandible and 42.3% of them were located in the anterior maxilla. Of the odontomas, 80.7% were related to disturbances in tooth eruption. Bone expansion was observed in 65.3% of the cases. All odontomas were surgically removed, and related impacted permanent teeth were either left to erupt spontaneously, orthodontically guided into occlusion or were removed. Orthodontic intervention appeared to be necessary in older children, while in younger children spontaneous eruption was frequent. In the present study, odontomas were associated with unerupted or impacted teeth. Radiographic examination was essential to verify the presence of the tumor and early removal prevented tooth eruption failure and disturbances in a majority of the cases.

Locarnini S.,Research and Molecular Development | Hatzakis A.,National and Kapodistrian University of Athens | Chen D.-S.,National Taiwan University Hospital | Lok A.,University of Michigan
Journal of Hepatology | Year: 2015

The last 50 years of hepatitis B research has resulted in the development of effective screening assays for surveillance, vaccines for prevention and antiviral drugs that significantly improve patient clinical outcomes. Not surprisingly then, the global epidemiology of hepatitis B virus (HBV) is set to change dramatically over the next decade. For example, the success and the high coverage of universal HBV vaccination and the ageing cohorts of patients with chronic hepatitis B (CHB) will result in reductions of incidence and prevalence of chronic hepatitis, cirrhosis and probably hepatocellular carcinoma. This will be further accelerated by the impressive progress in the treatment outcomes for patients with CHB. In spite of this success, challenges remain, such as planning for the impact of migration from countries with high prevalence rates to those countries with low rates of HBV infection. The recent establishment of the World Health Organisation Global Hepatitis Program with the provision of a framework for global action has become the cornerstone for all countries to now frame their own particular national responses to control hepatitis B. An effective policy framework can prevent new infections, ensure people can access clinical care, and in doing so reduce the burden of infection at an individual, country and regional level. These developments present a real opportunity to reduce the significant, social and economic burden of global hepatitis B, ultimately the critical next steps to render the world hepatitis B free. © 2015 European Association for the Study of the Liver. Published by Elsevier B.V. All rights reserved.

Giamarellou H.,National and Kapodistrian University of Athens
International Journal of Antimicrobial Agents | Year: 2010

The emergence of multidrug-resistant (MDR) Gram-negative bacilli creates a big problem for the treatment of nosocomial infections. As the pharmaceutical pipeline wanes, the only therapeutic options are two revived antibacterials (colistin and fosfomycin), a newer one (tigecycline) and an early-phase neoglycoside (ACHN-490). Polymyxins, known since 1947, are mostly represented by polymyxin E (colistin), which has recently gained a principal position in the management of the most difficult-to-treat MDR Gram-negative pathogens - Pseudomonas aeruginosa, Acinetobacter baumannii and Klebsiella pneumoniae. However, despite promising therapeutic results in 59-75% of cases, the reported studies share common drawbacks, i.e. the absence of a control group, their retrospective nature, variable dosing and duration of therapy, simultaneous administration of other antibiotics in >70% and a lack of resistance development monitoring. The necessity for well-designed prospective clinical trials is therefore urgent. Fosfomycin is active in vitro against MDR Enterobacteriaceae, including a high proportion of P. aeruginosa; however, clinical experience is lacking with the parenteral formulation in MDR infection and on the best combinations to prevent resistance development. Tigecycline, which is active against MDR Enterobacteriaceae and A. baumannii, has shown satisfactory clinical experience. However, dosage adjustment is required because of low blood levels. ACHN-490, which has promising in vitro activity against MDR K. pneumoniae, is still in early phase II trials in urinary tract infections. Meanwhile, the strict application of infection control measures is the cornerstone of nosocomial infection prevention, and antibiotic stewardship, exemplified by appropriate duration of therapy and de-escalation policies, should not be overlooked. © 2010 Elsevier B.V. and the International Society of Chemotherapy.

Gagari E.,National and Kapodistrian University of Athens
JDDG - Journal of the German Society of Dermatology | Year: 2011

Desquamative gingivitis (DG) is a clinical descriptive term indicating "peeling gums". DG is usually the result of a disease process that causes separation of the epithelium from the underlying connective tissue in the oral masticatory mucosa. DG may be a manifestation of several mucocutaneous diseases, most commonly cicatricial pemphigoid, pemphigus vulgaris and lichen planus. Correct diagnosis of the underlying disease in DG patients requires careful clinical observation, detailed examination of medical history, biopsy and histopathological examination of the lesions as well as more specialized tests such as direct and indirect immunofluorescence. Treatment of DG consists of treating the underlying disease and often requires the use of immunosuppressive agents, such as corticosteroids. Elimination of local gingival irritants, such as dental plaque and calculus, can significantly improve the treatment outcome. © The Authors • Journal compilation © Blackwell Verlag GmbH.

Archontis V.,National and Kapodistrian University of Athens | Archontis V.,University of St. Andrews | Hood A.W.,University of St. Andrews | Tsinganos K.,National Observatory of Athens
Astrophysical Journal Letters | Year: 2014

We report on three-dimensional MHD simulations of recurrent mini coronal mass ejection (CME)-like eruptions in a small active region (AR), which is formed by the dynamical emergence of a twisted (not kink unstable) flux tube from the solar interior. The eruptions develop as a result of the repeated formation and expulsion of new flux ropes due to continuous emergence and reconnection of sheared field lines along the polarity inversion line of the AR. The acceleration of the eruptions is triggered by tether-cutting reconnection at the current sheet underneath the erupting field. We find that each explosive eruption is followed by reformation of a sigmoidal structure and a subsequent "sigmoid-to-flare arcade" transformation in the AR. These results might have implications for recurrent CMEs and eruptive sigmoids/flares observations and theoretical studies. © 2014. The American Astronomical Society. All rights reserved.

Vasileiadis G.I.,National and Kapodistrian University of Athens
Orthopedics | Year: 2011

Nonsteroidal anti-inflammatory drugs (NSAIDs) may prevent heterotopic ossification after total hip arthroplasty (THA). Cyclooxygenase 2 (COX-2) inhibitors may minimize side effects. The goal of this review was to compare the effectiveness and side effects of the perioperative use of selective COX-2 inhibitors with those of conventional NSAIDs in patients undergoing THA. We followed the systematic reviews' updated methods of the Cochrane Collaboration Back Review Group and searched MEDLINE, EMBASE, and Cochrane Central Register of Controlled Trials. We identified all randomized controlled trials until April 2009 enrolling THA patients and comparing COX-2 inhibitors to NSAIDs. We assessed their methodological quality and extracted data. Five randomized controlled trials were included. Prevention of heterotopic ossification and side effects with COX-2 inhibitors were significant in 2 studies. Discontinuation for side effects was not significant. COX-2 inhibitors do not prevent heterotopic ossification after THA significantly better than conventional NSAIDs, while they are advantageous regarding side effects. Copyright 2011, SLACK Incorporated.

Bogdanis G.C.,National and Kapodistrian University of Athens
Frontiers in Physiology | Year: 2012

The aim of this review was to examine the mechanisms by which physical activity and inactivity modify muscle fatigue. It is well known that acute or chronic increases in physical activity result in structural, metabolic, hormonal, neural, and molecular adaptations that increase the level of force or power that can be sustained by a muscle. These adaptations depend on the type, intensity, and volume of the exercise stimulus, but recent studies have highlighted the role of high intensity, short-duration exercise as a time-efficient method to achieve both anaerobic and aerobic/endurance type adaptations.The factors that determine the fatigue profile of a muscle during intense exercise include muscle fiber composition, neuromuscular characteristics, high energy metabolite stores, buffering capacity, ionic regulation, capillarization, and mitochondrial density. Muscle fiber-type transformation during exercise training is usually toward the intermediate type IIA at the expense of both type I and IIx myosin heavy-chain isoforms. High-intensity training results in increases of both glycolytic and oxidative enzymes, muscle capillarization, improved phosphocreatine resynthesis and regulation of K +, H +, and lactate ions. Decreases of the habitual activity level due to injury or sedentary lifestyle result in partial or even compete reversal of the adaptations due to previous training, manifested by reductions in fiber cross-sectional area, decreased oxidative capacity, and capillarization. Complete immobilization due to injury results in markedly decreased force output and fatigue resistance. Muscle unloading reduces electromyographic activity and causes muscle atrophy and significant decreases in capillarization and oxidative enzymes activity. The last part of the review discusses the beneficial effects of intermittent high-intensity exercise training in patients with different health conditions to demonstrate the powerful effect of exercise on health and well being. © 2012 Bogdanis.

Panagiotopoulos D.P.,National and Kapodistrian University of Athens
Open Sports Sciences Journal | Year: 2016

The physical movement and the athletic movement and, furthermore, the whole of the physical activity, are distinct from other activities due to the organization on the basis of which it is practiced, to the way it is conducted and implemented and to the objectives which it involves. The legal entities in general and the ones of the sports sector in particular have been constituted so as to cover specific social needs, in accordance with the provisions of the applicable regulations and the ones of the Constitution. In Physical Education and Sport there are many interesting legal entities, some governed by Private Law and some by Public Law. This athletic action and particularly the sports contest can be achieved only within a specific framework of rules governing the contest and of rules of law, so as for all the above mentioned issues to be regulated. The physical and the athletic activity, as sports’ manifestations, regulated by legal rules, constitute a specific cognitive field for both the sports science and the legal one. Sports rules are established in order to cover public and private interest in sport in the context of national and international sport activity. Sports rules, as the rules of the game, prevail over ordinary rules of law since they have been specially enacted for specific sports activities. The rules of ordinary law apply in sports for many issues. They may apply directly due to the lack of special sports rules or indirectly by absorption with analogous adaptation and implementation where appropriate. © Dimitrios P. Panagiotopoulos; Licensee Bentham Open.

Stathopoulos G.T.,University of Patras | Kalomenidis I.,National and Kapodistrian University of Athens
American Journal of Respiratory and Critical Care Medicine | Year: 2012

Malignant pleural effusion (MPE) poses a significant clinical problem. Current nonetiologic management is suboptimal in terms of efficacy and safety. In light of recent research progress, we propose herein a new view of MPE development, which may rapidly translate into meaningful changes in therapeutics. In addition to tumor-induced impairment of pleural fluid drainage, pertinent findings point toward another pathway to MPE formation: a vicious loop of interactions between pleural-based tumor cells and the host vasculature and immune system that results in increased net fluid production via enhanced plasma extravasation into the pleural space. The ability of tumor cells to trigger this cascade likely rests on a specific and distinct transcriptional repertoire, which results in important vasoactive events in the pleural space. Although the characterization of tumor-derived factors responsible for MPE development is in the making, an additional, indirect path to MPE was recently demonstrated: tumor cells recruit and co-opt host cells and mediators, which, in turn, amplify tumor cell-primed fluid leakage and impact tumor cell functions. Importantly, recent evidence suggests that the biologic events that culminate in clinical MPE are likely amenable to therapeutic inhibition and even prevention. In this perspective, the scientific basis for an update of current concepts of MPE formation is highlighted. Key questions for future research are posed. Finally, a vision for novel, effective, safe, and convenient treatment modalities that can be offered to outpatients with MPE is set forth. Copyright © 2012 by the American Thoracic Society.

Markopoulos C.,National and Kapodistrian University of Athens
Expert Review of Anticancer Therapy | Year: 2013

Oncotype DX® is a multigene assay that provides prognostic information in terms of 10-year distant recurrence and predicts the likelihood of adjuvant chemotherapy benefit in estrogen receptor positive breast cancer patients, based on the expression of a panel of 21 genes (16 cancer-related and five reference genes) from a tumor specimen (core biopsy or surgical resection). It has been validated using multiple prospectively designed studies of archived tumor specimens from well-controlled clinical studies. In different countries with varying therapeutic approaches, using Oncotype DX has consistently resulted in a significant reduction in the number of patients who are prescribed chemotherapy, and in addition, it can identify a smaller subset of patients who would benefit from chemotherapy among patients who would otherwise receive endocrine therapy alone. © 2013 Expert Reviews Ltd.

Safiruddin F.,Sint Lucas Andreas Hospital Amsterdam | Koutsourelakis I.,National and Kapodistrian University of Athens | De Vries N.,Sint Lucas Andreas Hospital Amsterdam
Laryngoscope | Year: 2014

Objectives/Hypothesis Currently, drug-induced sleep endoscopy (DISE) in obstructive sleep apnea (OSA) is predominantly performed in supine position. When positional therapy (avoidance of supine sleeping position in positional OSA (POSA) is implemented as (part of the) treatment, one should assess levels of obstruction in the other sleeping positions. Therefore, the current study examined the influence of difference head positions during DISE in patients with OSA and POSA. Study Design Consecutive prospective study. Methods DISE was performed in patients with an apnea hypopnea index at baseline polysomnography greater than 5 events/h. The upper airway was assessed at velum, oropharynx, tongue base, and epiglottis level in supine position. The patients head were then tilted to the left and the right side and the DISE findings were recorded. Results One hundred consecutive patients were included. In positional apneics (n = 67), lateral position was associated with decreased frequency of complete anteroposterior collapse at velum (P < 0.01), tongue base (P < 0.01), and epiglottis (P < 0.01) level - and increased frequency of partial anteroposterior collapse at velum (P < 0.01), tongue base (P < 0.01), and epiglottis (P <0.05) level in comparison with supine position. DISE findings showed no difference between the right and left position, whereas findings after head rotation were significantly different in comparison with the supine position. Conclusions Head rotation improves upper airway collapse during DISE in supine position. This improvement of upper airway patency is more predominant in POSA patients. Level of Evidence 4. © 2014 The American Laryngological, Rhinological and Otological Society, Inc.

Laoutidis Z.G.,Heinrich Heine University Dusseldorf | Kioulos K.T.,National and Kapodistrian University of Athens
Psychopharmacology | Year: 2014

Rationale: The primary antipsychotic-induced creatine kinase elevation (i.e., not due to neuroleptic malignant syndrome, extrapyramidal symptoms, etc.) is a poorly studied condition. Objectives: The aims of the present study were to provide an overview of published cases with antipsychotic-induced creatine kinase elevation and give recommendations for the clinical practice. Methods: PubMed and EMBASE were searched for eligible trials, case series, and case reports. We set a threshold at ten times the upper normal limit of the creatine kinase value in order to define an elevation as significant. Results: The prevalence of significant creatine kinase elevation ranged between 2 and 7 %. We found a total of 42 eligible cases. Men were overrepresented in our sample (81 %). Patients with myoglobinuria were more likely to be symptomatic (Fisher's exact test, p∈=∈0.006), whereas neither myoglobinuria (Mann-Whitney test, p∈>∈0.10) nor symptoms (Mann-Whitney test, p∈=∈0.64) were related to the magnitude of the creatine kinase (CK) elevation. In the majority of the cases, the antipsychotic medication was discontinued (86 %). Forced diuresis was given in 36 % of the patients. Eighty-three percent of the patients had no further complications. Only one case was found with a de novo acute renal failure. Conclusions: The discontinuation of the antipsychotic medication was a sufficient measure for the CK elevation to subside in the majority of the cases. Cases with myoglobinuria should eventually be treated more aggressively. Further recommendations for the clinical practice are presented. © 2014 Springer-Verlag Berlin Heidelberg.

Papadakis P.,Institute of Informatics and Telecommunications | Pratikakis I.,Institute of Informatics and Telecommunications | Theoharis T.,National and Kapodistrian University of Athens | Perantonis S.,Institute of Informatics and Telecommunications
International Journal of Computer Vision | Year: 2010

We present a novel 3D shape descriptor that uses a set of panoramic views of a 3D object which describe the position and orientation of the object's surface in 3D space. We obtain a panoramic view of a 3D object by projecting it to the lateral surface of a cylinder parallel to one of its three principal axes and centered at the centroid of the object. The object is projected to three perpendicular cylinders, each one aligned with one of its principal axes in order to capture the global shape of the object. For each projection we compute the corresponding 2D Discrete Fourier Transform as well as 2D Discrete Wavelet Transform. We further increase the retrieval performance by employing a local (unsupervised) relevance feedback technique that shifts the descriptor of an object closer to its cluster centroid in feature space. The effectiveness of the proposed 3D object retrieval methodology is demonstrated via an extensive consistent evaluation in standard benchmarks that clearly shows better performance against state-of-the-art 3D object retrieval methods. © 2009 Springer Science+Business Media, LLC.

Dimopoulos M.A.,National and Kapodistrian University of Athens
American Journal of Hematology | Year: 2011

The treatment of Waldenström's macroglobulinemia (WM) has changed over the last decades, mainly because of the introduction of nucleoside analogues and of rituximab while novel agents such as bortezomib have been recently introduced. We performed an analysis to investigate whether the outcome of patients with WM has improved over the last years, compared to that of patients who started treatment before new drugs became widely available, especially as part of the frontline treatment. We analyzed 345 symptomatic patients with WM: 130 who initiated treatment before and 215 who started treatment after January 1, 2000. Patients who started treatment in the latter group were older and had more often elevated beta2-microglobulin but the other characteristics were similar between the two groups. Most patients who started treatment before January 1, 2000 were treated upfront with alkylating agent-based regimens and most patients who started treatment after January 1, 2000 received rituximab-based regimens as initial treatment. Objective response (63 and 59%, respectively) and median overall survival, OS, (106.5 months for Group A and is estimated at 94 months for Group B, P = 0.327) were similar. There was also no difference regarding OS or cause specific survival (CSS) in each risk group according to IPSSWM. Our observation may be explained by the indolent course of WM in several patients and by the lack of profound cytoreduction in patients with high-risk disease. Possible differences in the 15- or 20-year survival rate between the two groups may be detected with further follow-up of these patients. © 2011 Wiley-Liss, Inc.

Kino T.,U.S. National Institutes of Health | Hurt D.E.,U.S. National Institutes of Health | Ichijo T.,U.S. National Institutes of Health | Nader N.,U.S. National Institutes of Health | Chrousos G.P.,National and Kapodistrian University of Athens
Science Signaling | Year: 2010

The availability of nutrients influences cellular growth and survival by affecting gene transcription. Glucocorticoids also influence gene transcription and have diverse activities on cell growth, energy expenditure, and survival. We found that the growth arrest-specific 5 (Gas5) noncoding RNA, which is abundant in cells whose growth has been arrested because of lack of nutrients or growth factors, sensitized cells to apoptosis by suppressing glucocorticoid-mediated induction of several responsive genes, including the one encoding cellular inhibitor of apoptosis 2. Gas5 bound to the DNA-binding domain of the glucocorticoid receptor (GR) by acting as a decoy glucocorticoid response element (GRE), thus competing with DNA GREs for binding to the GR. We conclude that Gas5 is a "riborepressor" of the GR, influencing cell survival and metabolic activities during starvation by modulating the transcriptional activity of the GR. Copyright 2008 the American Association for the Advancement of Science; all rights reserved.

Grammatikakis I.E.,National and Kapodistrian University of Athens
Journal of Maternal-Fetal and Neonatal Medicine | Year: 2011

Minoan Civilization (3000-1150 BC) was the first European civilization on the GREEK island of Crete. Fabulous architectonical constructions like great palaces, wonderful frescoes, and pottery as well as jewellery characterize this amazing civilization. According to all existing descriptions from ancient Greek historians and philosophers like Plato, Thucydides, Strabon but also from all the archaeological findings men and women lived freely and peacefully participating equal in all daily activities, sports, and games. The women were predominating. Minoan women enjoyed a higher social status than other women in later civilizations. Methods. Investigation of all the existing data concerning the Minoan culture. Archaeological databases, as well as data from the National University of Athens and other Greek historical institutions were collected and analyzed in order to present the Minoan culture. Conclusion. The Minoic civilization represents a paradigm of a well being society in which the woman played a dominant role. She was the 'mother' but also the 'active woman', who participated in all city activities. Four thousand years later a prototype of a society in which the role of the mother was recognized in an admirably way remains a magnificent paradigm. © 2011 Informa UK, Ltd.

Duntas L.H.,National and Kapodistrian University of Athens | Biondi B.,University of Naples Federico II
Seminars in Thrombosis and Hemostasis | Year: 2011

Subclinical hypothyroidism (SH) is a frequent condition affecting millions of people around the world. Defined by increased thyrotropin-stimulating hormone (TSH) and accompanied by normal thyroid hormone levels, SH reflects a mild tissue hypothyroidism that has been associated with metabolic derangements andalthough this issue is still contentiouspossibly with increased cardiovascular risk. Depending on the degree of TSH elevation, SH has accordingly been associated with hyperlipidemia, arterial hypertension, and cardiovascular disease (CVD), as well as, increasingly, newly emerging CVD risk factors such as serum C-reactive protein and retinol binding protein 4 levels. There have also been reports of abnormalities in glucose metabolism and of hemostatic parameters, mainly underscored by the increased activity of factor VII. This review discusses the results of the latest studies on the various parameters affected by SH while highlighting the need for timely treatment with levothyroxine. © 2011 by Thieme Medical Publishers, Inc.

Rampias T.,Yale University | Sasaki C.,Yale University | Psyrri A.,National and Kapodistrian University of Athens
Oral Oncology | Year: 2014

A growing subgroup of oropharyngeal cancers is initiated by infection with high-risk human papillomaviruses (HPVs). In parallel to mounting epidemiological evidence, solid experimental data support a causal association between HPV and a subset of oropharyngeal cancers. This Review summarizes the main events of the HPV life cycle, the functions of the viral oncoproteins, and the implications of HPV infection on their hosts, with an emphasis on carcinogenic mechanisms in oropharyngeal cancer. The demonstration that HPVs have a role in head and neck carcinogenesis has fuelled the expectation that HPV-targeted therapeutic strategies may prove curative in these cancers. © 2014 Elsevier Ltd. All rights reserved.

Tong Z.,Chalmers University of Technology | Bogris A.,National and Kapodistrian University of Athens | Karlsson M.,Chalmers University of Technology | Andrekson P.A.,Chalmers University of Technology
Optics Express | Year: 2010

For the first time, four different noise sources, which are amplified quantum noise, Raman phonon seeded excess noise, pump transferred noise (PTN), and pump residual noise, are considered simultaneously to model the wavelength-dependent noise figure in a singlepumped fiber optical parametric amplifier. An asymmetric signal NF spectrum induced by both Raman phonon seeded excess noise and Raman gain modified PTN is measured in the electrical domain. Theoretical results agree very well with the experimental data. The idler NF spectrum is also analyzed and measured, which shows a more symmetric profile. ©2010 Optical Society of America.

Tentolouris N.K.,National and Kapodistrian University of Athens
Nature Reviews Endocrinology | Year: 2011

Painful diabetic neuropathy is a common complication of diabetes mellitus. Based on strong evidence, recently published guidelines suggest that pregabalin should be offered as first-line therapy in patients with painful symptoms. Nevertheless, other agents and nonpharmacological therapies may also be effective for the treatment of painful diabetic neuropathy. © 2011 Macmillan Publishers Limited. All rights reserved.

Petrakis T.G.,National and Kapodistrian University of Athens
Transcription | Year: 2012

Research in the last decade revealed an additional role for the Replication Licensing Factor Cdc6 in transcriptional regulation. This novel function has been linked to human cancer development. Here, we summarize all the findings arguing over a role of Cdc6 as a transcriptional repressor and shed light toward new research directions for this field.

Katakis I.,National and Kapodistrian University of Athens
Information Systems | Year: 2015

Modern cities are flooded with data. New information sources like public transport and wearable devices provide opportunities for novel applications that will improve citizens' quality of life. From a data science perspective, data emerging from smart cities give rise to a lot of challenges that constitute a new inter-disciplinary field of research. This article introduces the first part of a special issue on the topic 'Mining Urban Data' published in the journal Information Systems. © 2015 Published by Elsevier Ltd.

Alsamak S.,National and Kapodistrian University of Athens
The International journal of oral & maxillofacial implants | Year: 2013

To investigate the adequacy of potential sites for insertion of orthodontic mini-implants (OMIs) in the anterior alveolar region (delimited by the first premolars) through a systematic review of studies that used computed tomography (CT) or cone beam CT (CBCT) to assess anatomical hard tissue parameters, such as bone thickness, available space, and bone density. MEDLINE, EMBASE, and the Cochrane Database of Systematic Reviews were searched to identify all relevant papers published between 1980 and September 2011. An extensive search strategy was performed that included the key words "computerized (computed) tomography" and "mini-implants." Information was extracted from the eligible articles for three anatomical areas: maxillary anterior buccal, maxillary anterior palatal, and mandibular anterior buccal. Quantitative data obtained for each anatomical variable under study were evaluated qualitatively with a scoring system. Of the 790 articles identified by the search, 8 were eligible to be included in the study. The most favorable area for OMI insertion in the anterior maxilla (buccally and palatally) and mandible is between the canine and the first premolar. The best alternative area in the maxilla (buccally) and the mandible is between the lateral incisor and the canine, while in the maxillary palatal area it is between the central incisors or between the lateral incisor and the canine. Although there is considerable heterogeneity among studies, there is a good level of agreement regarding the optimal site for OMI placement in the anterior region among investigations of anatomical hard tissue parameters based on CT or CBCT scans. In this context, the area between the lateral incisor and the first premolar is the most favorable. However, interroot distance seems to be a critical factor that should be evaluated carefully.

Dalakas M.C.,Thomas Jefferson University | Dalakas M.C.,National and Kapodistrian University of Athens
Autoimmunity Reviews | Year: 2013

Background: Myasthenia Gravis (MG) is an autoimmune disease caused by complement-fixing antibodies against the acetylcholine receptors (AChR). Antigen-specific CD4. + T cells, Tregs and Th17. + are also necessary. Consequently, antibodies, B cells, molecules associated with signalling pathways on T helper cells, cytokines and complement are targets for more specific treatment options. Objectives: Because available immunosuppressive therapies cause unacceptable side effects after long-term use or are not always effective in inducing remission, novel biological agents directed against the following targets might be options for future therapies in MG: 1) T cell Intracellular Signaling Pathways associated with T cell activation, such as monoclonal antibodies against CD52, Interleukin 2-receptor (IL-2 R), co-stimulatory molecules or compounds inhibiting Janus tyrosine kinases JAK1, JAK3; 2) B cells, against key B cell-surface molecules or trophic factors B cell activation factor (BAFF) and a proliferating inducing ligand (APRIL); 3) Complement, against C3 or C5 that intercept membranolytic attack complex formation; 4) Cytokines and cytokine receptors, including IL-6, IL-17, the p40 subunit of IL12/1L-23, and GM-CSF; and 5) Lymphocyte migration molecules. Construction of recombinant AChR antibodies that block the binding of the pathogenic antibodies, can be a future molecular tool. Conclusion: New biological agents are in the offing for future therapies in MG. Their efficacy needs to be secured with vigorously controlled clinical trials and weighted against excessive cost and rare complications. © 2013 Elsevier B.V.

Karagounis P.,National and Kapodistrian University of Athens
Foot & ankle specialist | Year: 2011

Plantar fasciitis (PF) commonly causes inferior heel pain and occurs in up to 10% of the US population. Treatment protocols in most studies include the use of ice therapy, nonsteroidal anti-inflammatory drugs (NSAIDs), and stretching and strengthening protocols. The aim of the current study was to examine the effectiveness of 2 different therapeutic approaches on the treatment of PF in recreational athletes using the Pain and Disability Scale for the evaluation. A total of 38 participants with PF were randomly allocated to 2 different groups of 19 male participants in each group. Group 1 was treated with ice, non-steroidal anti-inflammatory medication, and a stretching and a strengthening program. Group 2 received the same therapeutic procedures as group 1, reinforced by acupuncture treatment. The primary outcomes, nominated a priori, were pain description and mobility-function at 1 and 2 months. Outcomes were measured with the pain scale for PF. The mean total score of the acupuncture group at the third measurement was statistically minor compared with the mean total score of the first group. Acupuncture should be considered as a major therapeutic instrument for the decrease of heel pain, combined with traditional medical approaches.

Daikos G.L.,National and Kapodistrian University of Athens | Markogiannakis A.,Laikon General Hospital
Clinical Microbiology and Infection | Year: 2011

Infections caused by carbapenemase-producing Klebsiella pneumoniae (CPKP) are increasing in frequency worldwide. CPKP isolates exhibit extensive drug resistance phenotypes, complicate therapy, and limit treatment options. Although CPKP isolates are often highly resistant to carbapenems, a proportion of these have relatively low MICs for carbapenems, raising the question of whether this class of agents has any therapeutic potential against CPKP infections. Results from animal studies and patient outcome data indicate that carbapenems retain meaningful in vitro activity against CPKP isolates with carbapenem MICs of ≤4mg/L. Accumulating clinical experience also suggests that the therapeutic efficacy of carbapenems against CPKP isolates with MICs of ≤4mg/L is enhanced when these agents are administered in combination with another active antibiotic. The results of human pharmacokinetic/pharmacodynamic studies are in line with the above observations; it is highly probable that a high-dose/prolonged-infusion regimen of a carbapenem would attain a time above the MIC value of 50% for CPKP isolates with MICs up to 4mg/L, ensuring acceptable drug exposure and favourable treatment outcome. The analyses summarized in this review support the notion that carbapenems have their place in the treatment of CPKP infections and that the currently proposed EUCAST clinical breakpoints could direct physicians in making treatment decisions. © 2011 European Society of Clinical Microbiology and Infectious Diseases.

Voudouris P.C.,National and Kapodistrian University of Athens
Mineralogy and Petrology | Year: 2011

The Mavrokoryfi Cu-Ag-Au-Te prospect, northeastern Greece, consists of atypical, high-sulfidation mineralization where precious metals were introduced contemporaneously with advanced argillic alteration from magmatic vapors. It occurs as veins of massive sulfides in zones of silicic and advanced argillic alteration spatially associated with an andesitic lava dome and hyaloclastites. Mineralogical data demonstrate an unusual ore and gangue mineralogy that is compatible with formation under very oxidizing conditions (logfO2 values of >-31.8) at temperatures of 200°C to 250°C. Oxidizing conditions favored the formation of hypogene lead sulfates (anglesite and barian celestite) instead of galena. Selenian acanthite, cadmian freibergite, and argentian goldfieldite are the main carriers of silver in the deposit and are reported in Greece for the first time. They were deposited at logfS2 of -9 to -7 and logfTe2 values of -9 to -12.5 (250°C). Ag-poor goldfieldite at Mavrokoryfi has up to 3.7 apfu Te and is the most Te-rich goldfieldite yet reported. The mineralization is accompanied by aluminum-phosphate-sulfate minerals of magmatic-hydrothermal origin and an unusual Pb-enrichment. Ore-forming components were likely derived from andesite porphyries. © 2010 Springer-Verlag.

Itsios G.,University of Patras | Sfetsos K.,National and Kapodistrian University of Athens | Siampos K.,University of Mons | Torrielli A.,University of Surrey
Nuclear Physics B | Year: 2014

We construct the Lax-pair, the classical monodromy matrix and the corresponding solution of the Yang-Baxter equation, for a two-parameter deformation of the Principal chiral model for a simple group. This deformation includes as a one-parameter subset, a class of integrable gauged WZW-type theories interpolating between the WZW model and the non-Abelian T-dual of the principal chiral model. We derive in full detail the Yangian algebra using two independent methods: by computing the algebra of the non-local charges and alternatively through an expansion of the Maillet brackets for the monodromy matrix. As a byproduct, we also provide a detailed general proof of the Serre relations for the Yangian symmetry. © 2014 The Authors.Published by Elsevier B.V.

Siristatidis C.S.,National and Kapodistrian University of Athens
The Cochrane database of systematic reviews | Year: 2013

Polycystic ovarian syndrome (PCOS) occurs in 4% to 7% of all women of reproductive age and 50% of women presenting with subfertility. Subfertility affects 15% to 20% of couples trying to conceive. A significant proportion of these women ultimately need assisted reproductive technology (ART). In vitro fertilisation (IVF) is one of the assisted reproduction techniques employed to raise the chances of achieving a pregnancy. For the standard IVF technique, stimulating follicle development and growth before oocyte retrieval is essential, for which a large number of different methods combining gonadotrophins with a gonadotrophin-releasing hormone (GnRH) agonist or antagonist are used. In women with PCOS, the supra-physiological doses of gonadotrophins used for controlled ovarian hyperstimulation (COH) often result in an exaggerated ovarian response, characterised by the development of a large cohort of follicles of uneven quality, retrieval of immature oocytes, and increased risk of ovarian hyperstimulation syndrome. A potentially effective intervention for women with PCOS-related subfertility involves earlier retrieval of immature oocytes at the germinal-vesicle stage followed by in vitro maturation (IVM). So far, the only data available have derived from observational studies and non-randomised clinical trials. To compare outcomes associated with in vitro maturation (IVM) followed by vitro fertilisation (IVF) or intracytoplasmic sperm injection (ICSI) versus conventional IVF or ICSI, among women with polycystic ovarian syndrome (PCOS) undergoing assisted reproductive technologies (ART). We searched the Menstrual Disorders and Subfertility Group (MDSG) Specialised Register of controlled trials to May 2013 for any relevant trials identified from the title, abstract, or keyword sections. This was followed by a search of the electronic database MEDLINE, EMBASE, LILACS and CINAHL, without language restriction. We also performed a manual search of the references of all retrieved articles; sought unpublished papers and abstracts submitted to international conferences, searched the clinicaltrials.gov and WHO portal registries for submitted protocols of clinical trials, and contacted experts. In addition, we examined the National Institute of Clinical Excellence (NICE) fertility assessment and treatment guidelines and handsearched reference lists of relevant articles (from 1970 to May 2013). All randomised trials (RCTs) on the intention to perform IVM before IVF or ICSI compared with conventional IVF or ICSI for subfertile women with PCOS. Three review authors (CS, MK and NV) independently assessed eligibility and quality of trials. Primary outcome measure was live birth rate per randomised woman. There were no RCTs suitable for inclusion in the review, although there are currently three ongoing trials that have not yet reported results. Though promising data on the IVM technique have been published, unfortunately there is still no evidence from RCTs upon which to base any practice recommendations regarding IVM before IVF or ICSI for women with PCOS. Meanwhile, the results of the above-mentioned ongoing trials are awaited and, of course, further evidence from good quality trials in the field is eagerly anticipated.

Giataganas D.,National and Kapodistrian University of Athens | Soltanpanahi H.,Jagiellonian University | Soltanpanahi H.,University of Witwatersrand
Journal of High Energy Physics | Year: 2014

We study the Langevin diffusion of a relativistic heavy quark in anisotropic strongly coupled theories in the local limit. Firstly, we use the axion space-dependent deformed anisotropic ℕ = 4 sYM, where the geometry anisotropy is always prolate, while the pressure anisotropy may be prolate or oblate. For motion along the anisotropic direction we find that the effective temperature for the quark can be larger than the heat bath temperature, in contrast to what happens in the isotropic theory. The longitudinal and transverse Langevin diffusion coefficients depend strongly on the anisotropy, the direction of motion and the transverse direction considered. We analyze the anisotropy effects to the coefficients and compare them to each other and to them of the isotropic theory. To examine the dependence of the coefficients on the type of the geometry, we consider another bottom-up anisotropic model. Changing the geometry from prolate to oblate, certain diffusion coefficients interchange their behaviors. In both anisotropic backgrounds we find cases that the transverse diffusion coefficient is larger than the longitudinal, but we find no negative excess noise. © 2014 The Author(s).

Sfetsos K.,National and Kapodistrian University of Athens | Thompson D.C.,Vrije Universiteit Brussel
Journal of High Energy Physics | Year: 2014

We present a family of (formula presented) =1 supersymmetric backgrounds in type-IIA super-gravity and their lifts to eleven-dimensional supergravity. These are of the form AdS5 × X5 and are characterised by an SU(2) structure. The internal space, X5, is obtained from the known Sasaki-Einstein manifolds, Yp, q, via an application of non-Abelian T-duality. © The Author(s).

Sfetsos K.,National and Kapodistrian University of Athens | Thompson D.C.,Vrije Universiteit Brussel
Journal of High Energy Physics | Year: 2014

Abstract: We examine a recently proposed class of integrable deformations to two-dimensional conformal field theories. These λ-deformations interpolate between a WZW model and the non-Abelian T-dual of a Principal Chiral Model on a group G or, between a G/H gauged WZW model and the non-Abelian T-dual of the geometric coset G/H. λ-deformations have been conjectured to represent quantum group q-deformations for the case where the deformation parameter is a root of unity. In this work we show how such deformations can be given an embedding as full string backgrounds whose target spaces satisfy the equations of type-II supergravity. One illustrative example is a deformation of the (Formula presented.) black-hole CFT. A further example interpolates between the (Formula presented.) gauged WZW model and the non-Abelian T-dual of AdS3 × S3 × T4 supported with Ramond flux. © 2014, The Author(s).

Markopoulos C.,National and Kapodistrian University of Athens | Van De Water W.,Leiden University
Therapeutic Advances in Medical Oncology | Year: 2012

Breast cancer is the most frequent malignant tumor in women worldwide and as breast cancer incidence increases with increasing age, over 40% of new cases are diagnosed in women older than 65 years of age. However, older patients are not treated to the same extent as younger patients and increasing age at diagnosis predicts deviation from guidelines for all treatment modalities. Evidence-based medicine in older patients is lacking as they are usually excluded from clinical trials often because of existing comorbidities and limited life expectancy. Accordingly, there is a higher competing risk of death from other causes than breast cancer compared with younger patients and this may have led to the false interpretation that prognosis of breast cancer in older patients is relatively good. However, every treatment modality should be evaluated during treatment decision making. Multimodal therapy should not be routinely withheld as data show that disease-specific mortality increases with age, probably due to undertreatment. Prognostic markers, fitness and comorbidities rather than chronological age should determine optimal, individualized therapy. It is recommended that treatment decisions should be discussed in a multidisciplinary setting, ideally in combination with any form of geriatric assessment, to improve breast cancer outcome in the older population. © The Author(s), 2012.

Dalakas M.C.,National and Kapodistrian University of Athens
Journal of the Peripheral Nervous System | Year: 2012

The main chronic autoimmune neuropathies include chronic inflammatory demyelinating polyneuropathy (CIDP), multifocal motor neuropathy (MMN), and anti-myelin-associated glycoprotein (MAG) demyelinating neuropathy. On the basis of randomized controlled studies, corticosteroids, intravenous immunoglobulin (IVIg), and plasmapheresis provide short-term benefits in CIDP. MMN responds only to IVIg. Because in MMN and CIDP, IVIg infusions are required every 3-6 weeks to sustain benefits or long-term remissions, there is a need for "IVIg-sparing" agents. In CIDP, immunosuppressive drugs, such as azathioprine, cyclosporine, methotrexate, mycophenolate, and cyclophosphamide, are used, but controlled trials have not shown that they are effective. Controlled trials have also not shown benefit to any agents in anti-MAG neuropathy. However, clinicians use many immunosuppressive drugs in both settings, but all have potentially serious side effects and are only effective in some patients. Thus, there is a need for new therapies in the inflammatory and paraproteinemic neuropathies. New agents targeting T cells, B cells, and transmigration and transduction molecules are discussed as potential treatment options for new trials. The need for biomarkers that predict therapeutic responses or identify patients with active disease is emphasized, and the search for better scoring tools that capture meaningful changes after response to therapies is highlighted. © 2012 Peripheral Nerve Society.

Evelpidou N.,National and Kapodistrian University of Athens | Vassilopoulos A.,Geoenvironmental Institute | Pirazzoli P.A.,French National Center for Scientific Research
Geomorphology | Year: 2012

Detailed mapping along the coasts of Skyros Island (Aegean Sea) provided new evidence concerning the rates and the modality of subsidence in the area. The results are provided through the study of the shape and the dimensions of the two submerged notches detected around the carbonate coasts of the island.It is apparent that the island has been submerged not only due to the global sea-level rise during the last two centuries (1.8 ± 0.3. mm/year between 1950 and 2000), but also because of tectonic events testified by the type of the submerged notches. Some of these tectonic events seem to be of gradual and some of co-seismic origin. The transition of MSL from the retreat point of the lower notch to the retreat point of the upper notch seems to have been produced by co-seismic subsidence of about 55. cm at slightly less than 850. years BP. © 2011 Elsevier B.V..

Santamouris M.,National and Kapodistrian University of Athens | Santamouris M.,Cyprus Institute
Energy and Buildings | Year: 2014

Urban heat island and global warming increase ambient temperature and modify the energy budget of buildings. The magnitude of the modification has been evaluated in a large number of articles, under different climatic and building boundary conditions. This paper collects, analyzes and classifies existing knowledge regarding the energy impact of urban heating to buildings and calculates preliminary indicators and impact figures. Based on the analysis of the impact studies, it is found that in average the cooling load of typical urban buildings is by 13% higher compared to similar buildings in rural areas. Four specific energy impact indicators, the global energy penalty per m2, the global energy penalty per m2 and degree of UHI, the global energy penalty per person and the global energy penalty per person and per degree of the UHI are defined and calculated. The variability of the heating and cooling loads of typical buildings is evaluated for the period 1970-2010. The average increase of the cooling demand is 23% while the corresponding average reduction of the heating is 19%. In total, the average energy consumption of typical buildings for heating and cooling purposes increased by 11% for the same period. © 2014 Elsevier B.V.

Background: Organisms are constantly exposed to physiological and environmental stresses and therefore require an efficient surveillance of genome and proteome quality in order to prevent disruption of homeostasis. Central to the intra- and extracellular proteome surveillance system are the molecular chaperones that contribute to both proteome maintenance and clearance. The conventional protein product of the apolipoprotein J/clusterin (CLU) gene is a heterodimeric secreted glycoprotein (also termed as sCLU) with a ubiquitous expression in human tissues. CLU exerts a small heat shock protein-like stress-induced chaperone activity and has been functionally implicated in numerous physiological processes as well as in ageing and most age-related diseases including tumorigenesis, neurodegeneration, and cardiovascular and metabolic syndromes. Objective: The CLU gene is differentially regulated by a wide variety of stimuli due to the combined presence of many distinct regulatory elements in its promoter that make it an extremely sensitive cellular biosensor of environmental and/or oxidative stress. Downstream to CLU gene induction, the CLU protein seems to actively intervene in pathological states of increased oxidative injury due to its chaperone-related property to inhibit protein aggregation and precipitation (a main feature of oxidant injury), as well as due to its reported distribution in both extra- and, most likely, intracellular compartments. Conclusion: On the basis of these findings, CLU has emerged as a unique regulator of cellular proteostasis. Nevertheless, it seemingly exerts a dual function in pathology. For instance, in normal cells and during early phases of carcinogenesis, CLU may inhibit tumor progression as it contributes to suppression of proteotoxic stress. In advanced neoplasia, however, it may offer a significant survival advantage in the tumor by suppressing many therapeutic stressors and enhancing metastasis. This review will critically present a synopsis of recent novel findings that relate to the function of this amazing molecule and support the notion that CLU is a biosensor of oxidative injury; a common link between ageing and all pathologies where CLU has been implicated. Potential future perspectives, implications and opportunities for translational research and the development of new therapies will be discussed. Copyright © 2013 S. Karger AG, Basel.

Liebchen B.,University of Hamburg | Diakonos F.K.,National and Kapodistrian University of Athens | Schmelcher P.,University of Hamburg
New Journal of Physics | Year: 2012

Long-range interactions are shown to cause, as time evolves, consecutive reversals of directed currents for dilute ensembles of particles in driven lattices. These current reversals are based on a general mechanism that leads to an interaction-induced accumulation of particles in the regular regions of the underlying single-particle phase space and to a synchronized single-particle motion as well as enhanced efficiency of Hamiltonian ratchets. Suggestions for experimental implementations using ionized mesoscopic clusters in micromechanical lattices or dipolarly interacting colloidal particles in ac-driven optical lattices are provided. © IOP Publishing Ltd and Deutsche Physikalische Gesellschaft.

Santamouris M.,National and Kapodistrian University of Athens | Kolokotsa D.,Technical University of Crete
Energy and Buildings | Year: 2013

Passive cooling in the built environment is now reaching is phase of maturity. Passive cooling is achieved by the use of techniques for solar and heat control, heat amortization and heat dissipation. Modulation of heat gain deals with the thermal storage capacity of the building structure, while heat dissipation techniques deal with the potential for disposal of excess heat of the building to an environmental sink of lower temperature, like the ground, water, and ambient air or sky. The aim of the present paper is to underline and review the recent state of the art technologies for passive cooling dissipation techniques in the built environment and their contribution in the improvement of the indoor environmental quality as well as in the reduction of cooling needs. The paper starts with a short introduction in passive cooling and continues with the analysis of advanced heat dissipation techniques such as ground cooling, evaporative cooling, and night ventilation in the built environment. The various technologies are compared versus their contribution to energy efficiency and users' comfort. Future trends and prospects are discussed. © 2012 Elsevier B.V.

Alexandrou C.,University of Cyprus | Papanicolas C.N.,National and Kapodistrian University of Athens | Vanderhaeghen M.,Johannes Gutenberg University Mainz
Reviews of Modern Physics | Year: 2012

This Colloquium addresses the issue of the shape of hadrons and, in particular, that of the proton. The concept of shape in the microcosm is critically examined. Special attention is devoted to properly define the meaning of shape for bound-state systems of near massless quarks. The ideas that lead to the expectation of nonsphericity in the shape of hadrons, the calculations that predict it, and the experimental information obtained from recent high-precision measurements are examined. Particular emphasis is given to the study of the electromagnetic transition between the nucleon and its first excited state, the Δ(1232) resonance. The experimental evidence is critically examined and compared with lattice calculations, as well as with effective-field theories and phenomenological models. © 2012 American Physical Society.

Moustakas A.L.,National and Kapodistrian University of Athens
IEEE International Symposium on Information Theory - Proceedings | Year: 2011

Linear MMSE reception offers a low complexity option for multi-antenna communication systems. Understanding the outage behavior of the corresponding signal-to-interference-and-noise ratio (SINR) and per-antenna throughput r is important in a quasistatic mobile environment. In this paper we introduce a large deviations method, valid nominally for large antenna numbers N, which calculates the probability density of the SINR and r of Gaussian channel MIMO MMSE receivers, with arbitrary transmission power profiles and in the presence of transmitter antenna correlations. This approach extends the Gaussian approximation of the SINR, valid only very close to the center of the distribution, demonstrating the non-Gaussian tails of the distribution. Our methodology allows us to calculate the correct leading order (O(N)) of the SINR distribution and showcase the deviations from approximations that have appeared in the literature (e.g. the Gaussian or the generalized Gamma distribution). We are also able to calculate next-to-leading order corrections to the distribution, thereby making the approximation quite accurate even for the smallest antenna arrays (2 × 2). © 2011 IEEE.

Dimitrakopoulos G.,National and Kapodistrian University of Athens
2011 11th International Conference on ITS Telecommunications, ITST 2011 | Year: 2011

Information and Communication Technologies (ICT) rapidly migrate towards the Future Internet (FI) era, which is characterized, among others, by powerful and complex network infrastructures and innovative applications, services and content. An application area that attracts immense research interest is transportation. In particular, traffic congestions, emergencies and accidents reveal inefficiencies in transportation infrastructures, which can be overcome through the exploitation of ICT findings, in designing systems that are targeted at traffic / emergency management, namely Intelligent Transportation Systems (ITS). This paper considers the potential connection of vehicles to form vehicular networks that communicate with each other at an IP-based level, exchange information either directly or indirectly (e.g. through social networking applications and web communities) and contribute to a more efficient and green future world of transportation. In particular, the paper presents the basic research areas that are associated with the concept of Internet of Vehicles (IoV) and outlines the fundamental research challenges that arise there from. © 2011 IEEE.

Tsivgoulis G.,National and Kapodistrian University of Athens
Stroke | Year: 2015

BACKGROUND AND PURPOSE—: There are limited data on the potential association of adherence to Mediterranean diet (MeD) with incident stroke. We sought to assess the longitudinal association between greater adherence to MeD and risk of incident stroke.METHODS—: We prospectively evaluated a population-based cohort of 30 239 individuals enrolled in REasons for Geographic and Racial Differences in Stroke (REGARDS) study, after excluding participants with stroke history, missing demographic data or food frequency questionnaires, and unavailable follow-up information. Adherence to MeD was categorized using MeD score. Incident stroke was adjudicated by expert panel review of medical records during a mean follow-up period of 6.5 years.RESULTS—: Incident stroke was identified in 565 participants (2.8%; 497 and 68 cases of ischemic stroke [IS] and hemorrhagic stroke, respectively) of 20 197 individuals fulfilling the inclusion criteria. High adherence to MeD (MeD score, 5–9) was associated with lower risk of incident IS in unadjusted analyses (hazard ratio, 0.83; 95% confidence interval, 0.70–1.00; P=0.046). The former association retained its significance (hazard ratio, 0.79; 95% confidence interval, 0.65–0.96; P=0.016) after adjustment for demographics, vascular risk factors, blood pressure levels, and antihypertensive medications. When MeD was evaluated as a continuous variable, a 1-point increase in MeD score was independently associated with a 5% reduction in the risk of incident IS (95% confidence interval, 0–11%). We documented no association of adherence to MeD with incident hemorrhagic stroke. There was no interaction of race (P=0.37) on the association of adherence to MeD with incident IS.CONCLUSIONS—: High adherence to MeD seems to be associated with a lower risk of incident IS independent of potential confounders. Adherence to MeD is not related to the risk of incident hemorrhagic stroke. © 2015 American Heart Association, Inc.

Michalakis K.,National and Kapodistrian University of Athens | Mintziori G.,Aristotle University of Thessaloniki | Kaprara A.,Aristotle University of Thessaloniki | Tarlatzis B.C.,Aristotle University of Thessaloniki | Goulis D.G.,Aristotle University of Thessaloniki
Metabolism: Clinical and Experimental | Year: 2013

The aim of this narrative review is to provide current evidence for the interaction between obesity, metabolic syndrome (MS) and reproductive axis. Gonadotropin-releasing hormone (GnRH) pulses and, consequently, normal function of reproductive (hypothalamus-pituitary-gonadal) axis depend on normal energy balance, which presupposes sufficient food intake, reasonable energy consumption and average thermoregulatory costs. In case of an energy imbalance, reproductive dysfunction may occur. In young women, excessive leanness is accompanied by puberty delay, whereas premature puberty might be a manifestation of obesity. In a similar way, obesity in men affects fertility. Excess adipose tissue results in increased conversion of testosterone to estradiol, which may lead to secondary hypogonadism through reproductive axis suppression. Moreover, oxidative stress at the level of the testicular micro-environment may result in decreased spermatogenesis and sperm damage. Products of the adipocyte, such as leptin, adiponectin and resistin, and gut peptides, such as ghrelin, are considered to be crucial in the interaction between energy balance and reproduction. Finally, an indirect evidence for the interplay between MS and reproductive axis is the fact that when treating components of one, parameters of the other can be improved as well. These therapeutic interventions include lifestyle modifications, pharmacological agents, such as sex hormone replacement therapy, and surgical procedures. Although many issues remain unclear, the elucidation of the complex interaction between MS and reproductive axis will have obvious clinical implications in the therapeutic approach of both entities. © 2013 Elsevier Inc.

Peppas K.P.,Institute of Informatics and Telecommunications | Datsikas C.K.,National and Kapodistrian University of Athens
Journal of Optical Communications and Networking | Year: 2010

Using an accurate exponential bound for the Gaussian Q-function, we derive simple approximate closed-form expressions for the average symbol error probability (ASEP) of a free-space optical communication link using subcarrier intensity modulation (SIM) with general-order rectangular quadrature amplitude modulation (QAM) over atmospheric turbulence channels. To model the atmospheric turbulence conditions, the log-normal and the gamma-gamma distribution are used. Extensive numerical and computer simulation results are presented in order to verify the accuracy of the proposed mathematical analysis. © 2010 Optical Society of America.

Papathanassoglou E.D.,National and Kapodistrian University of Athens
Nursing in critical care | Year: 2010

AIMS AND OBJECTIVES: To critically review evidence on the hypothesis that the multitude of cognitive and psychological stressors perceived by critically ill individuals may contribute to the development of pathophysiologic sequlae through modulation of the levels of stress neuropeptides. BACKGROUND: Critically ill individuals experience high levels of stress and intense adverse emotions. Although psychological stress has long been recognized as a factor in disease, and despite the nursing tenet on the importance of patients' psychological responses, in critical care, the potential physiologic effects of stress have received little attention. DESIGN, METHODS: Narrative critical review. Databases searched included Medline, CINAHL, PubMed and the Cochrane Library. Evidence on the role of stress neuropeptides and pertinent findings in critically ill individuals are reviewed. RESULTS: Limbic and extra-limbic brain structures along with specific stress neuropeptides [corticotrophin releasing hormone (CRH), adrenocorticotropin hormone (ACTH), neuropeptide Y , vasopressin, prolactin, oxytocin, substance P, cholecystokinin, endorphins, enkephalins, somatostatin, noradrenaline, melatonin] are involved in emotional and stress responses. Research evidence indicates that stress neuropeptide levels may be altered in critical illness. Moreover, they mediate processes such as immunity, endothelial response and oxidative stress. A framework for future research and practice is presented. CONCLUSIONS: It is probable that, in critical illness, psychological stress accentuates pathophysiological sequlae, through release of neuropeptides. The role of neuropeptides is suggested as an important field of investigation for critical care nursing. However, currently available data are insufficient to draw firm conclusions. Focussed studies on the physiologic correlates of psychological stress in the critically ill are needed. RELEVANCE TO CLINICAL PRACTICE: If this hypothesis is corroborated, bedside quantification of selected neuropeptides may contribute to the assessment of stress and of the effectiveness of psychological support interventions in the future. Moreover, psychosocial and, probably, pharmacological support interventions may be effective adjuncts to the care of the critically ill.

Duntas L.H.,National and Kapodistrian University of Athens | Brenta G.,Dr. Cesar Milstein Hospital
Medical Clinics of North America | Year: 2012

Thyroid hormones regulate cholesterol and lipoprotein metabolism, whereas thyroid disorders, including overt and subclinical hypothyroidism, considerably alter lipid profile and promote cardiovascular disease. Good evidence shows that high thyroid-stimulating hormone (TSH) is associated with a nonfavorable lipid profile, although TSH has no cutoff threshold for its association with lipids. Thyromimetics represent a new class of hypolipidemic drugs: their imminent application in patients with severe dyslipidemias, combined or not with statins, will improve the lipid profile, potentially accelerate energy expenditure and, as a consequence, vitally lessen the risk of cardiovascular disease. © 2012 Elsevier Inc.

Stefanaki I.,National and Kapodistrian University of Athens
Skin therapy letter | Year: 2010

Seborrheic dermatitis is a recurrent, usually mild, skin disorder with typical clinical manifestations. As it most frequently involves exposed areas, such as the face and scalp, patients seek advice from a dermatologist in order to control their disease. This article will review the available treatments for this common dermatologic problem.

Lykouras L.,National and Kapodistrian University of Athens
Psychiatrikē = Psychiatriki | Year: 2011

Anxiety disorders are the most prevalent mental disorders in developed countries. On the other hand, obesity is recognized to be one of the greatest public health problems worldwide.The connection between body weight and mental disorders remains an open issue. Low body weight has been studied enough (anorexia nervosa is a typical example) but high body weight has not been addressed sufficiently. It is known that obesity has been related with depression. Although moderate level of evidence exists for a positive association between obesity and anxiety disorders, the exact association between these two conditions is not clear yet.The studies about this subject are quite few and they follow different methodology. Furthermore,anxiety disorders share some common elements such as anxiety, avoidance and chronicity, but they also present a great deal of differences in phenomenology, neurobiology, treatment response and prognosis. This factor makes general conclusions difficult to be drawn. Obesity has been associated with anxiety disorders as following: most of the studies show a positive relationship with panic disorder, mainly in women, with specific phobia and social phobia. Some authors have found a relationship with generalised anxiety disorder but a negative relationship has been also reported.Only few studies have found association between obesity and agoraphobia, panic attacks and posttraumatic stress disorder. There has not been reported a relationship between obesity and obsessive-compulsive disorder. The causal relationship from obesity to anxiety disorders and vice versa is still under investigation. Pharmacological factors used for obesity treatment, such as rimonabant,were associated with depression and anxiety. Questions still remain regarding the role of obesity severity and subtypes of anxiety disorders. Besides, it is well known that in the morbidly obese patients before undergoing surgical treatment, unusual prevalence of psychopathology, namely depression and anxiety disorders, is observed. Anxiety is also a common trait in personality disorders.There is no single personality type characteristic of the morbidly obese, they differ from the general population as their self-esteem and impulse control is lower. Obese patients present with passive-dependent and passive-aggressive personality traits, as well as a trend for somatization and problem denial. Their thinking is usually dichotomous and catastrophic. Obese patients also show low cooperativeness and fail to see the self as autonomous and integrated. When trying to participate in society roles they are subject to prejudice and discrimination and should be treated with concern to help alleviate their feelings of rejection and guilt.

Psaltopoulou T.,National and Kapodistrian University of Athens
Clinical Journal of Sport Medicine | Year: 2016

OBJECTIVE:: Physical activity represents a well-established way to prolong the life span; yet, it remains an unfulfilled goal for a great part of the population. In parallel, the burden of gastric cancer is considerable throughout the globe. In that context, the present meta-analysis aims to shed light on the association between physical activity and gastric cancer risk. DATA SOURCES:: Eligible observational studies were sought in PubMed up to June 01, 2015. In addition, a snowball procedure was conducted and contact with authors was implemented. Separate analyses were performed by type of physical activity (total; occupational; recreational), study design, published/provided data, anatomical site, and study location, along with stratification by gender. MAIN RESULTS:: Ten cohort studies (7551 incident cases in a total cohort size of 1 541 208 subjects) and 12 case–control studies (5803 cases and 73 629 controls) were eligible. “Any” type of physical activity was associated with lower risk of gastric cancer [pooled relative risk (RR) = 0.81; 95% CI: 0.73 to 0.89], which was reproducible in men (pooled RR = 0.87; 95% CI: 0.77-0.99). The protective effect was significant in the subgroup analyses of published data, noncardia cancer (pooled RR = 0.62; 95% CI: 0.52-0.75), and studies stemming from Asia (pooled RR = 0.82; 95% CI: 0.74-0.90). CONCLUSIONS:: This meta-analysis suggests a protective effect of physical activity regarding gastric cancer risk, especially in Asian populations. Copyright © 2016 Wolters Kluwer Health, Inc. All rights reserved.

Zangari M.,University of Utah | Terpos E.,National and Kapodistrian University of Athens | Zhan F.,University of Utah | Tricot G.,University of Utah
Cancer Treatment Reviews | Year: 2012

Bone disease is a key feature in multiple myeloma (MM) and can have a substantial impact on patient morbidity and quality-of-life. The pathogenesis of lytic bone disease in MM is complex and associated with increased osteoclast activity and impaired osteoblast function. Lytic lesions rarely heal in MM; however, the proteasome inhibitor bortezomib has been linked to increased bone formation and osteoblastic activity. Various clinical studies have reported a positive effect of bortezomib on bone health, including fewer bone disease-related MM progression events, increases in bone volume, and improvements in osteolytic lesions. Alkaline phosphatase (total and bone isoenzyme), a marker of bone formation, is increased during bortezomib treatment; the degree of increase may be associated with treatment response. Bortezomib is associated with a reduction in Dickkopf-1, an inhibitor of osteoblast function. Increases of other bone-formation markers and decreases of bone-resorption markers, have also been observed. These clinical effects are supported by preclinical data suggesting bortezomib is associated with an increase in bone formation and osteoblast numbers/activity, arising from direct effects of bortezomib and proteasome inhibition. As reviewed here, a growing body of evidence indicates that bortezomib exerts a positive effect on bone metabolism in MM and has a bone anabolic effect. © 2011 Elsevier Ltd.

Siakavellas S.I.,National and Kapodistrian University of Athens
Discovery medicine | Year: 2012

Crohn's disease is an immune-mediated disease that is characterized by chronic intestinal inflammation. Effector CD4+ T-lymphocytes are expanded in Crohn's disease-associated inflammatory lesions and play a critical role in the pathogenesis of this condition. Recently, a novel population of effector T-lymphocytes has been identified, which is clearly separated from the traditional Th1 and Th2 lineages and is characterized by the secretion of IL-17, hence its designation as Th17. The development of this population has been closely linked to IL-23, a member of the IL-12 family of cytokines. Converging lines of evidence support the hypothesis that the IL-23/Th17 axis is of pathogenic relevance for Crohn's disease. Protein and mRNA levels of IL-23, IL-17, and other Th17 effector cytokines, such as IL-21 and IL-22, are elevated in areas with active Crohn's disease-related inflammation, whereas lamina propria mononuclear cells from patients with Crohn's disease secrete increased amounts of IL-17 upon T-cell receptor-specific stimulation. Genome-wide association studies have identified several Crohn's disease-associated polymorphisms in genes that encode for proteins of the IL-23/Th17 pathway. Functional studies have shown that Th17-related effector cytokines induce pro-inflammatory responses that are components of the pathogenetic mechanisms of Crohn's disease, including recruitment of neutrophils via IL-8 induction, upregulation of inflammatory mediators such as TNF-α, IL-1β, and IL-6, and secretion of metalloproteinases by intestinal fibroblasts. Finally, in several animal models of intestinal inflammation, disease severity is ameliorated when the IL-23/Th17 pathway is rendered deficient. These findings point to a critically important role for IL-23/Th17-mediated immune responses in Crohn's disease pathogenesis and may offer unique therapeutic opportunities for patients.

Bogdanos C.,University Paris - Sud | Saridakis E.N.,National and Kapodistrian University of Athens
Classical and Quantum Gravity | Year: 2010

We investigate the scalar and tensor perturbations in Hoava gravity, with and without detailed balance, around a flat background. Once both types of perturbations are taken into account, it is revealed that the theory is plagued by ghost-like scalar instabilities in the range of parameters which would render it power-counting renormalizable, that cannot be overcome by simple tricks such as analytic continuation. Implementing a consistent flow between the UV and IR limits seems thus more challenging than initially presumed, regardless of whether the theory approaches general relativity at low energies or not. Even in the phenomenologically viable parameter space, the tensor sector leads to additional potential problems, such as fine-tunings and super-luminal propagation. © 2010 IOP Publishing Ltd.

Spyridopoulos T.N.,National and Kapodistrian University of Athens
Medical ultrasonography | Year: 2010

Renal artery stenosis (RAS) is the most common underlying medical condition in secondary hypertension among adults, representing about 5% of all cases of hypertension. Early diagnosis of RAS is an important clinical objective since interventional therapy may improve or cure hypertension and preserve renal function. Contrast angiography is the currently reference standard for the diagnosis of RAS; however, its invasive nature renders it unsuitable for screening purposes. Among screening tests used for the detection of RAS (computed tomography angiography, magnetic resonance angiography, radionuclide scanning), multiple studies have shown that color Doppler ultrasound (CDUS), although highly operator-dependent, can be an effective tool in the diagnosis of RAS. CDUS imaging is a simple, safe (noninvasive) and widely available technique; in addition, the procedure is painless and well tolerated by patients. In this concrete review we will underline the established color Doppler ultrasound criteria used for the detection of RAS, highlight their limitations and see how their combination may improve the diagnostic accuracy of this method.

Methenitis S.,National and Kapodistrian University of Athens
Medicine and Science in Sports and Exercise | Year: 2016

PURPOSE: Aim of the study was to explore the relationship between muscle fiber conduction velocity (MFCV), fiber type composition and power performance in participants with different training background. METHODS: 38 young males with different training background participated: sedentary (n=10), endurance runners (n=9), power-trained (n=10), strength-trained (n=9). They performed maximal countermovement jumps and maximal isometric leg press for the measurement of the rate of force development (RFD). Resting vastus lateralis (VL) MFCV was measured with intramuscular microelectrodes on a different occasion, while muscle fiber type and cross sectional area (CSA) of VL were evaluated through muscle biopsies one week later. RESULTS: MFCV, countermovement jump power, RFD, % cross sectional area (% CSA) of type II and IIx fibers were higher for the power-trained group (p<0.001). No difference was found between sedentary participants and endurance runners in these variables but both of these groups performed worse than strength/power participants. Close correlations were found between MFCV and fiber CSA as well as the %CSA of all fiber types as well as with RFD and countermovement jump power (r=0.712-0.943, p<0.005). Partial correlations revealed that the %CSA of IIx fibers dictates a large part of the correlation between MFCV and RFD, power performance. Significant models for the prediction of the %CSA of type IIa, II as well as the CSA of all muscle fibers based upon MFCV, RFD and CMJ were revealed (p=0.000). CONCLUSION: MFCV is closely associated with muscle fiber % CSA. RFD and jumping power are associated with the propagation of the action potentials along the muscle fibers. This link is regulated by the size and the distribution of type II, and especially type IIx muscle fibers. © 2016 American College of Sports Medicine

Mavridis I.N.,National and Kapodistrian University of Athens
Neurosurgery | Year: 2015

BACKGROUND:: The ambiguous term precuneal artery (PA) has several synonyms and anatomic definitions. OBJECTIVE:: To examine the arteries of the precuneus and describe the PA and its branching pattern. We defined the PA as the principal arterial supplier of the precuneus. METHODS:: Twenty formalin-fixed, colored latex–injected cadaveric heads were studied with the aid of an operating microscope and microsurgical instrumentation. After removal of the cerebrum from the cranial vault, we examined this vesselʼs anatomy. Anatomic features of the PA were investigated and assessed in relation to demographic and anthropometric variables. RESULTS:: The PA was always a pericallosal artery branch and, more specifically, the superior internal parietal artery (SIPA) in 86.84%, the inferior internal parietal artery in 2.63%, and their common stem in 10.53% of specimens. Anastomosing interhemispheric branches between the PAs were present in 20% of cases. Compared with the right PA, the left anastomosed nearly 3 times more often with the ipsilateral posterior cerebral artery. The average distance of the PAʼs origin from the posterior limit of the splenium was shown to be 9.4 mm longer in elderly individuals compared with younger ones. CONCLUSION:: The term PA complex (rather than PA) can better describe the principal arterial supplier of the precuneus, and the SIPA, inferior internal parietal artery, and their common stem were shown as the 3 contributing arteries, with the SIPA predominating. The average distance of the PA complex origin from the spleniumʼs posterior limit shows significant variation with respect to age. ABBREVIATIONS:: a, anastomoses of precuneal branches with the contralateral hemisphere parameterACA, anterior cerebral arteryACoA, anterior communicating arteryARCS, ascending ramus of the cingulate sulcusb, precuneal branches anastomosing with the ipsilateral posterior cerebral artery parameter; posterior cerebral arteryBMI, body mass indexc, precuneal branches at the medial hemispheric surface parameterCC, corpus callosumd, length of the ascending ramus of the cingulate sulcus parametere, distance of the precuneal artery origin from the posterior limit of the corpus callosum parameterIIPA, inferior internal parietal arteryPA, precuneal arteryPCA, posterior cerebral arteryPcA, pericallosal arterySIPA, superior internal parietal artery Copyright © by the Congress of Neurological Surgeons

Basilakos S.,Academy of Athens | Stavrinos P.,National and Kapodistrian University of Athens
Physical Review D - Particles, Fields, Gravitation and Cosmology | Year: 2013

We perform a detailed comparison between the Finsler-Randers cosmological model and the Dvali, Gabadadze, and Porrati (DGP) braneworld model. If we assume that the spatial curvature is strictly equal to zero then we prove the following interesting proposition: despite the fact that the current cosmological models have a completely different geometrical origin, they share exactly the same Hubble expansion. This implies that the Finsler-Randers model is cosmologically equivalent with that of the DGP model as far as the cosmic expansion is concerned. At the perturbative level we find that the Finsler-Randers growth index of matter perturbations is γFR 9/14, which is somewhat lower than that of DGP gravity (γDGP 11/16), implying that the growth factor of the Finsler-Randers model is slightly different (∼0.1-2%) from the one provided by the DGP gravity model. © 2013 American Physical Society.

Papaioannou K.A.,National and Kapodistrian University of Athens
The International journal of oral & maxillofacial implants | Year: 2011

To compare in vitro the attachment and proliferation of human osteoblast-like cells (MG63) on tissue culture plates and guided bone regeneration (GBR) membranes in the absence or presence of nicotine. Membrane samples were fixed to wells and the cell number (CN) was counted after 24 hours (attachment assay) or 5 days (proliferation assay). The ratio of cell count (RCC) (CN at 5 days/CN at 24 hours) was calculated. The study had three parts: First, five different resorbable GBR membranes were compared (Resolut Adapt LT [RALT], Biocollagen [BC], Bio-Gide [BG], OsseoGuard [OG], and Demokritos Human Tissue Bank [DEM]). Next, cells were cultured on tissue culture plates with five different concentrations of nicotine. Finally, cells were cultured on the membrane that had demonstrated the highest RCC and CN in part 1 with four different concentrations of nicotine. At 24 hours, BG showed the highest CN and OG showed the lowest CN. At 5 days, BG showed the highest CN. The order of RCC was BG > OG > DEM > RALT ~ BC. At 24 hours, lower nicotine concentrations (0.3 and 3 μg/mL) showed higher CNs versus the control, whereas CNs for high nicotine concentrations (30 and 300 μg/mL) were lower than for the control. CN at 5 days and RCC were lowest with 300 μg/mL nicotine. At 24 hours and 5 days, all differences among wells with membrane were statistically insignificant. Nevertheless, CN at 5 days and RCC were highest with the lowest nicotine concentration (3 μg/mL) and lowest with high concentrations. Membrane materials influence attachment and proliferation of bone cells and, therefore, could affect the outcomes of GBR. On both tissue culture plates and membranes, there is a tendency toward a biphasic effect of nicotine, with stimulatory effects at low concentrations and inhibitory effects at high concentrations.

Frantzeskakis D.J.,National and Kapodistrian University of Athens
Journal of Physics A: Mathematical and Theoretical | Year: 2010

This review paper presents an overview of the theoretical and experimental progress on the study of matter-wave dark solitons in atomic Bose-Einstein condensates. Upon introducing the general framework, we discuss the statics and dynamics of single and multiple matter-wave dark solitons in the quasi one-dimensional setting, in higher dimensional settings, as well as in the dimensionality crossover regime. Special attention is paid to the connection between theoretical results, obtained by various analytical approaches, and relevant experimental observations. © 2010 IOP Publishing Ltd.

Kokotos C.G.,National and Kapodistrian University of Athens
Journal of Organic Chemistry | Year: 2012

A systematic study to evaluate the ability of various organocatalysts to catalyze the aldol reaction between acetone and 2,2,2-trifluoromethyl-1- phenylethanone was undertaken. Benchmark organocatalysts failed to catalyzethis reaction. However, a prolinamide-thiourea consisting of (S)-prolinamide, (1S,2S)-diphenylethylenediamine, and (S)-di-tert butyl aspartate proved to be an efficient catalyst, providing tertiary alcohols as the products of the reaction between ketones and perfluoroalkyl ketones in high to quantitative yields and high enantioselectivities (up 81% ee) at a catalyst loading of 2 mol %. © 2011 American Chemical Society.

Kalles V.,National and Kapodistrian University of Athens
Tumour biology : the journal of the International Society for Oncodevelopmental Biology and Medicine | Year: 2012

Deregulation of the endothelin system, comprised of endothelin-1 (ET-1), its isoforms (ET-2 and ET-3) and their receptors (ET(A)R and ET(B)R), is under investigation in various types of human cancer. ET-1 has been suggested to participate in breast cancer development and progression, while Big ET-1, its biological precursor, has also been found elevated in breast cancer patients. In the present study, we investigated plasma ET-1 and Big ET-1 levels in patients with suspicious mammographic lesions, in order to assess their potential application as diagnostic biomarkers in the early estimation of breast disease. The study consisted of 94 patients (Group A to 30 patients with invasive ductal carcinoma: Group B, 30 with ductal carcinoma in situ; and group C, 34 with papilloma or ductal hyperplasia), who underwent an image-guided vacuum-assisted breast biopsy, and 30 healthy controls (group D). ET-1 and Big ET-1 plasma levels were measured with enzyme-linked immunosorbent assay. ET-1 levels did not exhibit significant differences between patients and healthy controls (Group A to 0.92 fmol/mL; Group B: 0.90 fmol/mL; Group C: 0.66 fmol/mL; and Group D: 0.86 fmol/mL). In contrast, Big ET-1 levels were significantly higher in patients with invasive or in situ carcinoma compared to healthy controls (Group A: 0.69 fmol/mL; Group B, 0.62 fmol/mL; and group D: 0.39 fmol/mL; p < 0.001 and p < 0.01). Plasma Big ET-1 may provide a useful tool for the early detection of invasive or noninvasive ductal breast cancer. The utilization of such a diagnostic tool would greatly assist in the modern management of breast cancer.

Michalaki M.,National and Kapodistrian University of Athens
European archives of paediatric dentistry : official journal of the European Academy of Paediatric Dentistry | Year: 2010

This was to evaluate the attitudes and knowledge of Greek Dentists concerning fissure sealants (FS) and other preventive measurements, together with the extent and the reasons for using or not using FS in their clinical practice. 1,221 general dental practitioners (GDPs) including 50 Paediatric Dentists (PD) were randomly selected from 35 local dental societies of Greece and asked to answer a telephone questionnaire regarding their attitudes to prevention, use of FS and variables influencing their placement. Non parametric Pearson's Chi square test and multifactorial logistic regression models were used for analysing the data. Although 87.6% of all Greek dentists believe and apply prevention, only 35.8% are using them routinely. Factors highly correlated with FS usage for all dentists were using fluoride regimens (p<0.001), being in practice for 5-14 years (p=0.004) and practicing in urban areas (p<0.001). By contrast, all PD were using FS, regardless of any parameter (p>0.01). Concerning the type of surfaces sealed, 45.6% of GDP used FS on intact surfaces and 41.1% on questionable, while only 15% of them sealed incipient caries. Overall, fewer GDPs compared with PD sealed premolars, primary teeth, questionable surfaces, incipient enamel caries and molars in high risk patients (p<0.001), while fewer PD sealed intact surfaces (p<0.001). The reasons mentioned for not using FS were: 76.3% that parents were unwilling to pay, 61.9% did not know how to use them, while 43.0% believed that oral hygiene was sufficient in order to reduce caries. Insufficient knowledge and lack of clinical practice guidelines for the use of FS by GDPs in Greece, leads to low usage rates. Appropriate professional and scientific authorities should join efforts to improve knowledge of GDP and instil confidence in using FS.

Koutsis G.,National and Kapodistrian University of Athens
European Journal of Human Genetics | Year: 2015

Hereditary Spastic Paraplegia (HSP) is a syndrome characterised by lower limb spasticity, occurring alone or in association with other neurological manifestations, such as cognitive impairment, seizures, ataxia or neuropathy. HSP occurs worldwide, with different populations having different frequencies of causative genes. The Greek population has not yet been characterised. The purpose of this study was to describe the clinical presentation and molecular epidemiology of the largest cohort of HSP in Greece, comprising 54 patients from 40 families. We used a targeted next-generation sequencing (NGS) approach to genetically assess a proband from each family. We made a genetic diagnosis in >50% of cases and identified 11 novel variants. Variants in SPAST and KIF5A were the most common causes of autosomal dominant HSP, whereas SPG11 and CYP7B1 were the most common cause of autosomal recessive HSP. We identified a novel variant in SPG11, which led to disease with later onset and may be unique to the Greek population and report the first nonsense mutation in KIF5A. Interestingly, the frequency of HSP mutations in the Greek population, which is relatively isolated, was very similar to other European populations. We confirm that NGS approaches are an efficient diagnostic tool and should be employed early in the assessment of HSP patients.European Journal of Human Genetics advance online publication, 16 September 2015; doi:10.1038/ejhg.2015.200. © 2015 Macmillan Publishers Limited

Dilis V.,National and Kapodistrian University of Athens | Trichopoulou A.,Hellenic Health Foundation
Journal of Nutrition | Year: 2010

Antioxidants are compounds physiologically produced or provided through the diet with a potential to inhibit the oxidation of important biological molecules, such as proteins, lipids, and DNA. The contemporary Greek diet is still strongly influenced by Mediterranean dietary traditions. The traditional Mediterranean diet (MD) is a plant-based diet with apparently beneficial health properties, to which a high antioxidant content may contribute. To explore this issue in detail, a database of the content of >200 Greek foods and recipes for a wide spectrum of antioxidant compounds and indices (flavonoids, proanthocyannidins, other antioxidant microcomponents, and total antioxidant capacity) was developed. The database enabled the estimation of antioxidant intakes in Greece using the population-based European Prospective Investigation into Cancer and Nutrition study, in which >28,000 Greeks participate. The results of this work suggest that the contemporaryMD in the Greek population is a rich source of a variety of antioxidants. These data can be used in studies about the relationship between antioxidant intake and chronic diseases in the Greek population. © 2010 American Society for Nutrition.

Terpos E.,National and Kapodistrian University of Athens
Anti-Cancer Agents in Medicinal Chemistry | Year: 2012

Bisphosphonates inhibit osteoclast-mediated bone resorption and have been used extensively to prevent skeletal-related events in patients with bone lesions from multiple myeloma (MM). In addition, in vitro and in vivo preclinical data suggest that bisphosphonates also have antimyeloma properties that may induce myeloma cell apoptosis, activate an anticancer immune response, inhibit angiogenesis, and reduce tumor burden, supporting an expanded role for bisphosphonates. Signals for improved survival in the clinic first emerged in retrospective analyses of MM patient subgroups in larger clinical trials. Recently, improved progression-free survival and overall survival with bisphosphonates have been reported in the overall populations of large-scale randomized clinical trials. Several ongoing clinical trials will help further define the role of bisphosphonates during antimyeloma therapy. Overall, bisphosphonates appear to be well tolerated in patients with MM; the most common adverse events are mild and can be easily managed. However, emphasis on renal monitoring and preventive dentistry are necessary to reduce the risk of potential adverse events, and have become the standard of care for patients with MM. © 2012 Bentham Science Publishers.

The temperature of cities continues to increase because of the heat island phenomenon and the undeniable climatic change. The observed high ambient temperatures intensify the energy problem of cities, deteriorates comfort conditions, put in danger the vulnerable population and amplify the pollution problems. To counterbalance the phenomenon, important mitigation technologies have been developed and proposed. Among them, technologies aiming to increase the albedo of cities and the use of vegetative - green roofs appear to be very promising, presenting a relatively high heat island mitigation potential. This paper aims to present the state of the art on both the above technologies, when applied in the city scale. Tenths of published studies have been analysed. Most of the available data are based on simulation studies using mesoscale modeling techniques while important data are available from the existing experimental studies. When a global increase of the city's albedo is considered, the expected mean decrease of the average ambient temperature is close to 0.3. K per 0.1 rise of the albedo, while the corresponding average decrease of the peak ambient temperature is close to 0.9. K. When only cool roofs are considered, the analysis of the existing data shows that the expected depression rate of the average urban ambient temperature varies between 0.1 and 0.33. K per 0.1 increase of the roofs albedo with a mean value close to 0.2. K. As it concerns green roofs, existing simulation studies show that when applied on a city scale, they may reduce the average ambient temperature between 0.3 and 3. K. Detailed analysis of many studies reporting a comparison of the mitigation potential of both technologies has permitted the definition of the limits, the boundaries and the conditions under which the considered technologies reach their better performance, in a synthetic way. © 2012 Elsevier Ltd.

Sapountzaki K.,National and Kapodistrian University of Athens
Natural Hazards | Year: 2012

The article decodes and analyzes the standard functions of social and social-ecological systems when they manage their own vulnerability. The author acknowledges these as "Resilience functions" or "Operational Resilience". For this purpose, she follows a "Vulnerability Actor" (V Actor)-based approach. V Actor is considered as a system faced with multiple hazards, carrying various vulnerability facets (physical, economic, institutional, etc.) and attempting to transform, transfer, rearrange them in time and space so as to achieve Actor's own persistence. It is these processes of vulnerability re-arrangement that are identified by the author as Resilience functions and which change the vulnerability not only of the V Actor performing resilience but also others'. Performance of Resilience functions presupposes attraction and employment of resources by the Actor, not only own, current and inherent but also other resources to be found in spatial and temporal scales external to or beyond the Actor but which the Actor can appeal to. This attraction most probably leads to deprivation of others of the necessary resources for their persistence, recovery, etc. When somebody' vulnerability is reduced sometimes somewhere, it is most probable that others elsewhere are encumbered with extra vulnerability, currently or in the future. Hence, what resilience can only do is vulnerability re-arrangement, re-setting and management. The proposed systemic approach is documented on current state of art regarding interactions between vulnerability and resilience to hazards and on empirical evidence from the international experience of responses to natural hazards. © 2011 Springer Science+Business Media B.V.

Diakakis M.,National and Kapodistrian University of Athens
Natural Hazards | Year: 2012

Basins across Mediterranean coast are often subject to rapid inundation phenomena caused by intense rainfall events. In this flash flooding regime, common practices for risk mitigation involve hydraulic modeling, geomorphic, and hydrologic analysis. However, apart from examining the intrinsic characteristics of a basin, realistic flood hazard assessment requires good understanding of the role of climatic forcing. In this work, peak rainfall intensities, total storm accumulation, average intensity, and antecedent moisture conditions of the 52 most important storms in record, during the period from 1993 to 2008, in northeast Attica, in Greece, are examined to investigate whether there is a correlation between specific rainfall conditions and flood triggering in the area. For this purpose, precipitation data from a network of five rain gauges installed across the study area were collected and analyzed. Storms totals, average intensity, antecedent moisture conditions, and peak intensities variations were calculated and compared with local flooding history. Results showed that among these rainfall measures, only peak storm intensity presents a significant correlation with flood triggering, and a rainfall threshold above which flooding becomes highly probable can be defined. © 2011 Springer Science+Business Media B.V.

Avrameas S.,National and Kapodistrian University of Athens | Avrameas S.,Hellenic Pasteur Institute | Selmi C.,Humanitas Clinical and Research Center | Selmi C.,University of California at Davis
Journal of Autoimmunity | Year: 2013

Natural autoantibodies (autoNAb) recognize self antigens and are an important component of the immune system, as species ranging from invertebrates to vertebrates have polyreactive IgM NAbs. In higher vertebrates, different polyreactive autoNAbs isotypes are also frequently encountered and autopolyreactive IgG NAbs are largely predominant compared to low-titer monoreactive IgG NAbs specific for either self or non-self antigens. Autopolyreactive NAbs manifest the capacity to recognize three-dimensional structures and thus represent a fundamental feature of the immune system that has long been preserved during evolution. NAbs are produced in a continuum of functional and phenotypic tiers of B cells and are likely to derive from proteins initially selected to build the organism that were adapted through evolution to recognize environmental constituents, while preserving their capacity to recognize self antigens. The clonal selection is considered the predominant mechanism of the regulation of the immune system complexity but growing evidence suggests that autoNAbs are also actively implicated. In all species NAbs reacting with either self or non-self antigens constitute a vast network of infinite interactions providing high complexity, stability and plasticity. This evolutionary process was intended to allow the effective recognition of environmental antigens, immune memory, immunoregulatory phenomena, as well as tissue homeostasis. The present article is intended to illustrate the history and the current and future developments in our understanding of self and non-self recognizing NAbs to ultimately enlighten the complexity of the immune system regulation. © 2013 Elsevier Ltd.

Diamanti-Kandarakis E.,National and Kapodistrian University of Athens
Therapeutic Advances in Endocrinology and Metabolism | Year: 2012

Polycystic ovary syndrome (PCOS) is a common endocrine disorder in women of reproductive age that is associated with significant adverse short- and long-term health consequences. Multiple metabolic aberrations, such as insulin resistance (IR) and hyperinsulinaemia, high incidence of impaired glucose tolerance, visceral obesity, inflammation and endothelial dysfunction, hypertension and dyslipidemia are associated with the syndrome. Assessing the metabolic aberrations and their long term health impact in women with PCOS is challenging and becomes more important as therapeutic interventions currently available for the management of PCOS are not fully able to deal with all these consequences. Current therapeutic management of PCOS has incorporated new treatments resulting from the better understanding of the pathophysiology of the syndrome. The aim of this review is to summarize the effect of old, new and emerging therapies used in the management of PCOS, on the metabolic aberrations of PCOS © The Author(s), 2012.

Eleftherakis-Papapiakovou E.,National and Kapodistrian University of Athens
Leukemia & lymphoma | Year: 2011

Abstract Renal impairment (RI) is a common presenting complication of multiple myeloma associated with significant morbidity and early mortality, while it has been associated with inferior survival in patients treated with conventional regimens. We assessed the impact of RI in 203 unselected consecutive patients treated upfront with novel agents (thalidomide, lenalidomide, bortezomib). RI was assessed by the estimated glomerular filtration rate (eGFR). RI (eGFR <60 mL/min) was present in 93 (45.8%) of patients at diagnosis and was associated with advanced age, advanced International Staging System (ISS) stage, poorer performance status, hypercalcemia, urine Bence-Jones proteinuria, anemia and thrombocytopenia. Myeloma response rates were similar for patients with or without RI. In univariate analysis RI was associated with shorter survival and a higher rate of early death (7% vs. 3.5%); however, when adjusted for other prognostic factors, RI was not independently associated with survival. In conclusion, in unselected newly diagnosed patients treated with novel agent-based therapies, RI is not independently associated with inferior survival, probably due to the significant activity of novel agents even in the context of RI.

Nastos P.T.,National and Kapodistrian University of Athens
Advances in Meteorology | Year: 2012

The Mediterranean Basin and southern Europe are often affected by Saharan dust outbreaks, which influence the aerosol load and properties, air quality standards, visibility and human health. The present work examines, mainly of the meteorological point of view, three intense dust outbreaks occurred over Greece with duration of one or two days, on 4 and 6 February and 5-6 March 2009. The synoptic analysis on the dusty days showed the presence of low-pressure systems in the west coasts of Europe and the north Tyrrhenian Sea, respectively, associated with a trough reaching the north African coast. The result of these conditions was the strong surface and mid troposphere winds that carried significant amounts of dust over Greece. During the dusty days extensive cloud cover associated with the dust plume occurred over Greece. The air-mass trajectories showed a clear Saharan origin in all atmospheric levels, while the satellite (MODIS Terra/Aqua) observations as well as the model (DREAM) predictions verified the intense dust outbreaks over eastern Mediterranean and Greece. The ground based particulate matter concentrations in Athens were excessively increased on the dusty days (PM 150-560 g/m3), while significant dry and wet deposition occurred as forecasted by DREAM model. © 2012 P. T. Nastos.

Sakellariou V.I.,National and Kapodistrian University of Athens
Advances in skin & wound care | Year: 2011

To evaluate the effect of negative-pressure wound therapy in musculoskeletal tumor surgery patients. The authors analyzed the medical records of 32 patients treated at the authors' institution for bone and soft-tissue sarcomas and secondary wound-healing complications, from 2005 to 2008; there were 11 men and 21 women, with a mean age of 56 years (range, 35-72 years). A statistically significant difference (P = .036) was found regarding the length of hospitalization in the conventional wound treatment group, group A (mean, 25.2 days; range, 15-52 days), compared with the negative wound pressure therapy group, group B (mean, 16.5 days; range, 12-33 days). The use of negative-pressure wound therapy for the management of complicated wound healing in sarcoma patients following tumor surgery is safe and effective and is associated with lower overall complications rates, infection rate, and the need for further surgery and a lower total cost of wound-healing treatment.

Saetta A.A.,National and Kapodistrian University of Athens
Virchows Archiv : an international journal of pathology | Year: 2011

Although pERK and pAKT are reportedly activated in various neoplasms, little information is available about their significance in astrocytomas. Paraffin-embedded tissue from 82 patients with diffuse infiltrating astrocytomas (grades II to IV) was investigated for the association of pERK and pAKT activation with clinicopathological features, vascular endothelial growth factor (VEGF), isocitrate dehydrogenase 1 and microvascular parameters. Nuclear pERK labelling index (LI) increased with increasing cytoplasmic pERK LI and nuclear and cytoplasmic pAKT LI (p=0.0019, p=0.0260 and p=0.0012, respectively). Accordingly, cytoplasmic pERK increased with increasing levels of nuclear (p=0.0001) and marginally with cytoplasmic pAKT LI (p=0.0526). Nuclear and cytoplasmic pERK LI and nuclear pAKT LI were positively correlated with tumour histological grade (p=0.0040, p=0.0238 for pERK and p=0.0004 for pAKT, respectively). VEGF expression was correlated with nuclear pERK (p=0.0099) and nuclear pAKT LI (p=0.0002). Interestingly, pERK cytoplasmic LI increased with microvessel calibre (p=0.0287), whereas pAKT nuclear LI was marginally related to microvessel density (p=0.0685). The presence of IDH1-R132H was related only to histological grade and lower microvessel calibre. Multivariate survival analysis in the entire cohort selected cytoplasmic pAKT LI (p=0.045), histological grade, microvessel calibre (p=0.028), patients' age, gender and surgical excision as independent predictors of survival. Moreover, in glioblastomas, pERK nuclear LI emerged as a favourable prognosticator in the presence of IDH1-R132H. pERK and pAKT in astrocytomas are interrelated and associated with tumour grade and angiogenesis. Moreover, the importance of cytoplasmic pAKT immunoexpression in patients' prognosis and nuclear pERK immunoexpression in glioblastomas is confirmed.

Fomin F.V.,University of Bergen | Golovach P.,Durham University | Thilikos D.M.,National and Kapodistrian University of Athens
Journal of Combinatorial Theory. Series B | Year: 2011

We provide two parameterized graphs Γk, Πk with the following property: for every positive integer k, there is a constant ck such that every graph G with treewidth at least ck, contains one of Kk, Γk, Πk as a contraction, where Kk is a complete graph on k vertices. These three parameterized graphs can be seen as "obstruction patterns" for the treewidth with respect to the contraction partial ordering. We also present some refinements of this result along with their algorithmic consequences. © 2011 Elsevier Inc.

Nirgianaki E.,National and Kapodistrian University of Athens
Journal of the Acoustical Society of America | Year: 2014

The present study examined the acoustics of Greek fricative consonants in terms of temporal, spectral, and amplitude parameters. The effects of voicing, speaker's gender, place of articulation, and post-fricative vowel on the acoustic parameters were also investigated. The results indicated that first and second spectral moments (i.e., spectral mean and spectral variance), as well as second formant (F2) onset, and normalized amplitude values are the acoustic parameters most correlated with the Greek fricative place of articulation distinction. F2 onset and spectral mean were the parameters that distinguished all five places of articulation, while normalized amplitude differentiated sibilants from non-sibilants. In addition, normalized duration and normalized amplitude are the parameters that distinguish Greek voiced from voiceless fricatives, with high classification accuracy. © 2014 Acoustical Society of America.

Bamidis P.D.,Aristotle University of Thessaloniki | Vivas A.B.,University of Sheffield | Styliadis C.,Aristotle University of Thessaloniki | Frantzidis C.,Aristotle University of Thessaloniki | And 4 more authors.
Neuroscience and Biobehavioral Reviews | Year: 2014

Maintaining a healthy brain is a critical factor for the quality of life of elderly individuals and the preservation of their independence. Challenging aging brains through cognitive training and physical exercises has shown to be effective against age-related cognitive decline and disease. But how effective are such training interventions? What is the optimal combination/strategy? Is there enough evidence from neuropsychological observations, animal studies, as well as, structural and functional neuroimaging investigations to interpret the underlying neurobiological mechanisms responsible for the observed neuroplasticity of the aging brain? This piece of work summarizes recent findings toward these questions, but also highlights the role of functional brain connectivity work, an emerging discipline for future research in healthy aging and the study of the underlying mechanisms across the life span. The ultimate aim is to conclude on recommended multimodal training, in light of contemporary trends in the design of exergaming interventions. The latter issue is discussed in conjunction with building up neuroscientific knowledge and envisaged future research challenges in mapping, understanding and training the aging brain. © 2014 Elsevier Ltd.

Antoniou A.A.,National Technical University of Athens | Lekkas E.,National and Kapodistrian University of Athens
Geomorphology | Year: 2010

This article analyzes rockfall susceptibility in the steep caldera slopes upstream of Athinios port, Santorini Island, Greece. The study area is situated in the internal rim of a submarine caldera where the most important problem that is recorded is the frequent rockfalls that not only cause damages to roads and vehicles but also pose a threat to people that are transported or located on the port. As a result, a methodology which combines information relatively to surficial and engineering geology, geomorphological processes, and structural analysis was adopted. The methodology incorporates evenly a maximum runout map generated by means of reach probability of rock block analysis, using the empirical model of "reach angle". Additionally volumes of rockfall events categorized and presented through a map to assist the compilation of rockfall susceptibility map which allows us to identify areas and human activities exposed to these incidents and set up several protection meters. © 2009 Elsevier B.V.

Tzeli D.,National Hellenic Research Foundation | Mavridis A.,National and Kapodistrian University of Athens
Journal of Chemical Physics | Year: 2010

For the ground states of the diatomic carbide FeC (X 3Δ) and its ions, FeC+ (X 2Δ) and FeC- (X 2Δ), we report on accurate multireference variational ab initio results employing augmented correlation consistent basis sets of quintuple cardinality. The dissociation energies and bond lengths are found to be D0 0 =87±1, 95.2, and 84±1 kcal/mol at re =1.581, 1.556, and 1.660 Å for FeC, FeC+, and FeC-, respectively. All our final numbers are in agreement with the available experimental data. © 2010 American Institute of Physics.

Mentzelopoulos S.D.,National and Kapodistrian University of Athens | Mantzanas M.,Ecclesiastical Academy of Athens | Van Belle G.,University of Washington | Nichol G.,University of Washington
Resuscitation | Year: 2015

Aim: Emergency research is necessary to prevent exposure of patients to unvalidated clinical practice (nonmaleficence), and to improve the dismal prognosis of disorders requiring emergent treatment such as cardiac arrest (beneficence). Regulations that govern clinical research should conform to bioethical principles of respect for nonmaleficence, beneficence, autonomy, and justice. Our objectives are to review the evolution of European Union (EU) legislation on emergency research, and to identify potentially remaining problems. Data sources: EU legislative sources on clinical research and medical literature describing the impact of EU Regulations on emergency research. Results: Article 5 of EU Directive 2001/20/EC required consent before enrolment in a research study to ensure the autonomy of potentially incapacitated research subjects. However, obtaining such consent is often impossible in emergency situations. Directive 2001/20/EC was criticized for potentially preventing emergency research. Several EU Member States addressed this problem by permitting deferred consent. International ethical guidelines supporting deferred consent were also cited by Good Clinical Practice Directive 2005/28/EC. However, Directive 2001/20/EC was not revised to achieve harmonization of EU emergency research, thus resulting in ongoing ". ambiguity" as regards to emergency research legitimacy. This will be definitively addressed by applying EU Regulation No. 536/2014 and repealing Directive 2001/20/EC. The new EU Regulation permits using deferred consent under clearly specified conditions, and may foster emergency research that evaluates interventions posing minimal risk relative to standard practice. Conclusions: Legislation related to emergency research in Europe has evolved to increase concordance with bioethical principles so as to increase evidence-based improvements in emergency care. © 2015 Elsevier Ireland Ltd.

Galanos P.,National and Kapodistrian University of Athens
Nature Cell Biology | Year: 2016

The cyclin-dependent kinase inhibitor p21WAF1/CIP1 (p21) is a cell-cycle checkpoint effector and inducer of senescence, regulated by p53. Yet, evidence suggests that p21 could also be oncogenic, through a mechanism that has so far remained obscure. We report that a subset of atypical cancerous cells strongly expressing p21 showed proliferation features. This occurred predominantly in p53-mutant human cancers, suggesting p53-independent upregulation of p21 selectively in more aggressive tumour cells. Multifaceted phenotypic and genomic analyses of p21-inducible, p53-null, cancerous and near-normal cellular models showed that after an initial senescence-like phase, a subpopulation of p21-expressing proliferating cells emerged, featuring increased genomic instability, aggressiveness and chemoresistance. Mechanistically, sustained p21 accumulation inhibited mainly the CRL4–CDT2 ubiquitin ligase, leading to deregulated origin licensing and replication stress. Collectively, our data reveal the tumour-promoting ability of p21 through deregulation of DNA replication licensing machinery—an unorthodox role to be considered in cancer treatment, since p21 responds to various stimuli including some chemotherapy drugs. © 2016 Nature Publishing Group

Dimopoulos M.A.,National and Kapodistrian University of Athens | Richardson P.G.,Dana-Farber Cancer Institute | Moreau P.,University of Nantes | Anderson K.C.,Dana-Farber Cancer Institute
Nature Reviews Clinical Oncology | Year: 2015

Recent developments in the treatment of multiple myeloma have led to improvements in response rates and to increased survival; however, relapse is inevitable in almost all patients. Recurrence of myeloma is typically more aggressive with each relapse, leading to the development of treatment-refractory disease, which is associated with a shorter survival. Several phase II and III trials have demonstrated the efficacy of recently approved agents in the setting of relapsed and/or refractory multiple myeloma, including immunomodulatory agents, such as lenalidomide and pomalidomide, and proteasome inhibitors, such as bortezomib and carfilzomib. Currently, however, there is no standard treatment for patients with relapsed and/or refractory disease. This Review discusses the current treatment landscape for patients with relapsed and/or refractory multiple myeloma and highlights disease-related and patient-related factors - such as pre-existing comorbidities or toxicities - that are important considerations for clinicians when selecting an appropriate treatment regimen.

Dagres N.,National and Kapodistrian University of Athens | Hindricks G.,University of Leipzig
European Heart Journal | Year: 2013

Patients who have experienced a myocardial infarction (MI) are at increased risk of sudden cardiac death (SCD). With the advent of implantable cardioverter-defibrillators (ICDs), accurate risk stratification has become very relevant. Numerous investigations have proven that a reduced left ventricular ejection fraction (LVEF) significantly increases the SCD risk. Furthermore, ICD implantation in patients with reduced LVEF confers significant survival benefit. As a result, LVEF is the cornerstone of current decision making for prophylactic ICD implantation after MI. However, LVEF as standalone risk stratifier has major limitations: (i) the majority of SCD cases occur in patients with preserved or moderately reduced LVEF, (ii) only relatively few patients with reduced LVEF will benefit from an ICD (most will never experience a threatening arrhythmic event, others have a high risk for non-sudden death), (iii) a reduced LVEF is a risk factor for both sudden and non-sudden death. Several other non-invasive and invasive risk stratifiers, such as ventricular ectopy, QRS duration, signal-averaged electrocardiogram, microvolt T-wave alternans, markers of autonomic tone as well as programmed ventricular stimulation, have been evaluated. However, none of these techniques has unequivocally demonstrated the efficacy when applied alone or in combination with LVEF. Apart from their limited sensitivity, most of them are risk factors for both sudden and non-sudden death. Considering the multiple mechanisms involved in SCD, it seems unlikely that a single test will prove adequate for all patients. A combination of clinical characteristics with selected stratification tools may significantly improve risk stratification in the future. © The Author 2013.

Katsarou A.,National and Kapodistrian University of Athens | Armenaka M.C.,Aristotle University of Thessaloniki
Journal of the European Academy of Dermatology and Venereology | Year: 2011

We review the particular characteristics of atopic dermatitis (AD) in adult life, and compare findings with those of AD in childhood. AD affects 1-3% of adults world-wide, and can present as adult-onset AD, or as infantile/childhood AD that persists, or recurs after many years. Eczema in adults usually exists for years, compromising quality of life, sex life and occupational choices. The flexural areas, shoulders, head-and-neck, and hands are typically affected. In elderly adults, eczematous erythroderma is common. The intrinsic (non-IgE-allergic) eczema subtype affects 5-15% of cases. Classical food allergy has a low importance, although non-IgE-mediated and pseudoallergic reactions can cause eczema. Sensitivity to aeroallergens, especially dust mite, is demonstrated in the majority of adult AD patients, including elderly adults, by immunoglobulin E-mediated tests and/or atopy patch tests. Occupational allergic and irritant contact dermatitis is increased. In adults, as in children, Staphylococcus aureus colonization is very high, whereas adult skin is more heavily colonized with Malassezia yeasts. Immediate and delayed sensitization to Malassezia sympodialis is specific for intrinsic and extrinsic AD, occurring especially in head-and-neck eczema. Concerning therapy, older patients are prone to certain adverse drug effects. In conclusion, differences exist between childhood and adult disease. As we should be seeing more adults with AD in the future, there is a need for more clinical and immunological studies in older patients. © 2010 European Academy of Dermatology and Venereology.

Dalamaga M.,National and Kapodistrian University of Athens | Chou S.H.,Beth Israel Deaconess Medical Center | Shields K.,Beth Israel Deaconess Medical Center | Papageorgiou P.,Beth Israel Deaconess Medical Center | And 3 more authors.
Cell Metabolism | Year: 2013

Since its discovery as an adipocyte-secreted hormone, leptin has been found to impact food intake, energy homeostasis, and metabolism through its effects on the central nervous system and peripheral organs. Recent research indicates that leptin may also be involved in cognition, immune function, and bone metabolism. These findings place leptin at the intersection of neuroendocrinology and metabolism, and possibly immune function, and render it an appealing therapeutic target for several niche areas of unmet clinical need. Current evidence regarding classic and emerging roles of leptin as well as the pros and cons of its potential clinical use are summarized herein. © 2013 Elsevier Inc.

Kelepertzis E.,National and Kapodistrian University of Athens
Ecotoxicology and Environmental Safety | Year: 2014

The present study investigates the possible influence of human activities on metal loadings of topsoil in a typical small rural city in central Greece and the chemical quality of tap water in surrounding villages. Furthermore, the study aimed to examine potential health risks of naturally enriched heavy metals to exposed population taking into account the soil and drinking water as exposure pathways. The mean concentrations of Ni, Cr, Co, Mn, Pb, Cu, Zn and Cd in the soil were 1777, 285, 99, 946, 30, 26, 78 and 0.67. mg/kg respectively. Combination of pollution indexes based on local reference background soils and statistical analyses (correlation analysis, cluster analysis and principal component analysis) revealed that anthropogenic activities have not modified the natural soil chemistry at least in a large scale. High Hazard Quotient (HQ) values for children were estimated for Ni, Cr and Co based on total metal concentrations for the soil ingestion route (9.26E-01, 9.75E-01 and 3.45E+00 respectively). However, evaluation of HQs based on published bioaccessible concentrations suggested that the population groups would not likely experience potential health risks as a result of exposure to contaminated soils. Concentrations of Cr(VI) in tap waters were within the allowable limits. However, the risk assessment model revealed that local residents (adults) of Eleonas and Neochori villages are at some carcinogenic risks considering lifetime ingestion of water (potential cancer risks 2.05E-04 and 1.29E-04 respectively). Despite the uncertainties accompanying these procedures and the great deal of debate regarding the human carcinogenicity of Cr(VI) by the oral route, results of this study drive attention to remediation measures that should include epidemiological studies for the local population. © 2013 Elsevier Inc.

Komis G.,National and Kapodistrian University of Athens | Illes P.,Palacky University | Beck M.,Norwich Research Park | Samaj J.,Palacky University
Current Opinion in Plant Biology | Year: 2011

Subcellular signalling by mitogen-activated protein kinases (MAPKs) was originally regarded as a means to regulate microtubule (MT) organization and dynamics, but with time MAPKs were assigned to broader roles concerning biotic and abiotic signal transductions. MAPKs, which regulate a broad spectrum of substrates including transcription factors and cytoskeletal proteins, belong to complex MAPK cascades, which are mainly involved in plant development and in plant stress responses. The fact that single MAPK can be regulated by more than a single MAPKKK/MAPKK pair make MAPK signalling modules versatile tools in the regulation of microtubule organization. Until recently, the best-studied MAPK module implicated in cytoskeletal regulation is the NACK-PQR pathway in tobacco (Nicotiana tabacum). Homologues of each constituent of this pathway were also discovered in Arabidopsis thaliana. So far, direct phosphorylation of tubulins by MAPKs has not been shown. However, the first MAPK-related substrate involved in the regulation of MT dynamics to have been identified is MT-associated protein MAP65-1. © 2011 Elsevier Ltd.

The Kassiteres-Sapes area is a telescoped porphyry Cu-Mo-Re ± Au and epithermal Au-Ag-Cu-Te system, hosted within Oligocene calc-alkaline to high-K calc-alkaline granodiorite-tonalite, microdiorite and quartz-feldspar porphyries and their volcanic equivalents. High- And intermediate sulfidation epithermal mineralization was deposited in advanced argillic lithocaps that overprint sodic/potassic and sericitic alteration of the intrusive rocks. Deep level, corundum-sericite-feldspar-, corundum-quartz-, and quartz-diaspore-topaz-APS minerals-pyrophyllite-sericite bearing assemblages occur in close proximity to porphyry-style mineralization at the Koryfes, Konos Hills and St Demetrios deposits. Rapid cooling of ascending magmatic-hydrothermal solutions at pressures below 0.6 kb and temperatures above 370 ?C could dilute quartz resulting in silica undersaturation and the formation of corundum-sericite at Koryfes Hill. The corundum-quartz assemblage at St Demetrios was likely derived from previous diasporebearing advanced argillic alteration at moderate temperature ( 400 °C) and low pressure, followed by rapid depressurization accompanying boiling of the hydrothermal fluid. The disequilibrium assemblage quartz+diaspore+topaz (± pyrophyllite ? sericite) formed between 285? and 320 ?C by vapor saturation pressure from acid solutions after condensation of vapors released from the porphyries. The presence of topaz reflects the presence of fluorine in the fluid. Alumino-phosphates-sulfates (woodhouseite, Sr-rich woodhouseite and Sr-Ce-rich woodhouseite) are present as pseudocubic crystals enclosed within diaspore and natroalunite. High level lithocaps include natroalunite/alunite-kaolinite/dickite-pyrite bearing assemblages of both replacement- And vein-type, which deposited at 300° to 200 °C by increasing acidity of the fluid at higher topographic levels and/or from direct input of magmatic vapors. Episodic magmatic-hydrothermal activity in the district is characterized by several stages of advanced argillic alteration and associated Au-Ag-Cu-Te high-sulfidation mineralization. ©2014 E. Schweizerbart'sche Verlagsbuchhandlung, Stuttgart, Germany.

Varbobitis I.C.,National and Kapodistrian University of Athens
European Journal of Gastroenterology and Hepatology | Year: 2016

BACKGROUND/AIM: Two-dimensional shear-wave elastography (2D-SWE) is a new elastographic technique that is increasingly being used across several indications. We assessed the reliability and applicability of 2D-SWE in patients with various chronic liver diseases and attempted to identify parameters potentially affecting liver stiffness. METHODS: We included all patients with chronic liver disease who underwent 2D-SWE examination over a 15-month period. Patients with acute hepatitis, active cholestatic disease, or severe heart failure were excluded. The procedures were performed by three adequately trained operators. Standard operating procedures for liver ultrasonography and elastography were followed. RESULTS: 2D-SWE was reliable in 98% of 605 patients. SD to mean liver stiffness value ratio greater than 9.14%, which was considered an indicator of reliability, was associated independently with age more than 50 years, obesity, or overweight, and use of statins for hyperlipidemia. 2D-SWE was applicable, requiring a median time of 7 min per examination and exceeding 15 min in only 5.5% of patients. Worse applicability expressed as duration more than 0.7 min per reliable measurement was associated independently with age more than 50 years and obesity. The mean and median liver stiffness values were 11.6 and 7.7 kPa, respectively. Liver stiffness more than 7.7 kPa was associated independently with age more than 50 years and increased waist circumference. CONCLUSION: 2D-SWE represents an applicable method of assessment of liver fibrosis that can provide reliable results in the vast majority of patients with chronic liver diseases. Older age and obesity may affect the reliability and applicability of the method as well as the severity of liver fibrosis. Copyright © 2016 Wolters Kluwer Health, Inc. All rights reserved.

Al-Dashti H.,Directorate General of Kuwait Civil Aviation | Spyrou C.,National and Kapodistrian University of Athens
Atmospheric Chemistry and Physics | Year: 2014

Dust aerosols are analyzed for their optical and physical properties during an episode of a dust storm that blew over Kuwait on 26 March 2003 when the military Operation Iraqi Freedom was in full swing. The intensity of the dust storm was such that it left a thick suspension of dust throughout the following day, 27 March. The synoptic sequence leading to the dust storm and the associated wind fields are discussed. Ground-based measurements of aerosol optical thickness reached 3.617 and 4.17 on 26 and 27 March respectively while the Ångstrom coefficient, α870/440, dropped to -0.0234 and -0.0318. Particulate matter concentration of 10 Ǐ1/4m diameter or less, PM10, peaked at 4800 Ǐ1/4g m-3 during dust storm hours of 26 March. Moderate Resolution Imaging Spectroradiometer (MODIS) retrieved aerosol optical depth (AOD) by Deep Blue algorithm and Total Ozone Mapping Spectrometer (TOMS) aerosol index (AI) exhibited high values. Latitude-longitude maps of AOD and AI were used to deduce source regions of dust transport over Kuwait. The vertical profile of the dust layer was simulated using the SKIRON atmospheric model. Instantaneous net direct radiative forcing is calculated at top of atmosphere (TOA) and surface level. The thick dust layer of 26 March resulted in cooling the TOA by -60 Wm-2 and surface level by -175 Wm-2 for a surface albedo of 0.35. Slightly higher values were obtained for 27 March due to the increase in aerosol optical thickness. Radiative heating/cooling rates in the shortwave and longwave bands were also examined. Shortwave heating rate reached a maximum value of 2 K day-1 between 3 and 5 km, dropped to 1.5 K day-1 at 6 km and diminished at 8 km. Longwave radiation initially heated the lower atmosphere by a maximum value of 0.2 K day-1 at surface level, declined sharply at increasing altitude and diminished at 4 km. Above 4 km longwave radiation started to cool the atmosphere slightly reaching a maximum rate of -0.1 K day-1 at 6 km. © Author(s) 2014.

Rallidis L.S.,National and Kapodistrian University of Athens
Current Opinion in Cardiology | Year: 2016

PURPOSE OF REVIEW: Smoking is the most prevalent risk factor among young patients suffering acute myocardial infarction (AMI). In this review, we will present data on the detrimental consequences of continued smoking with regard to the recurrence of coronary events after an AMI at an early age. RECENT FINDINGS: A prospective study with long-term follow-up of young survivors of AMI showed that continuation of smoking after a first episode of AMI was the strongest independent predictor of further cardiac events. In particular, persistent smokers had ∼2.5 times higher risk of a new coronary event when compared with nonsmokers. This emphasizes the fundamental importance of initiating smoking cessation treatment in all smokers with AMI during hospitalization. Extrapolating the results of previous studies showing the benefits of smoking cessation in middle-aged or elderly coronary patients, an even greater benefit should be expected in young patients because of their specific characteristics, which are presented in the current review. SUMMARY: Young persistent smokers after a premature AMI constitute a high-risk subgroup for a recurrence of cardiac events. Therefore, smoking cessation is a key issue for improving their prognosis and all smokers should be offered effective antismoking treatment at the time of initial hospitalization. Copyright © 2016 Wolters Kluwer Health, Inc. All rights reserved.

Kanaka-Gantenbein C.,National and Kapodistrian University of Athens
Annals of the New York Academy of Sciences | Year: 2010

According to the fetal origin of adult diseases hypothesis, the intrauterine environment through developmental plasticity may permanently influence long-term health and disease. Therefore, intrauterine growth restriction (IUGR), due either to maternal, placental, or genetic factors, may permanently alter the endocrine-metabolic status of the fetus, driving an insulin resistance state that can promote survival at the short term but that facilitates the development of type 2 diabetes mellitus and metabolic syndrome in adult life, especially when the intrauterine nutrient restriction is followed by a postnatal obesogenic environment. Furthermore, an energy-rich environment during fetal programming may also drive the development of excess abdominal fat and type 2 diabetes in later life, demonstrating that both intrauterine nutrient restriction as well as intrauterine nutrient excessive supply may predispose for the development of adult diabetes. © 2010 New York Academy of Sciences.

Lianidou E.S.,National and Kapodistrian University of Athens
Molecular Oncology | Year: 2016

A variety of molecular assays have been developed for CTCs detection and molecular characterization. Molecular assays are based on the nucleic acid analysis in CTCs and are based on total RNA isolation and subsequent mRNA quantification of specific genes, or isolation of genomic DNA that can be for DNA methylation studies and mutation analysis. This review is mainly focused on gene expression and methylation studies in CTCs in various types of cancer. © 2016 Federation of European Biochemical Societies.

Kalemos A.,National and Kapodistrian University of Athens
Journal of Chemical Physics | Year: 2013

The XΣu+2 BNB state considered to be of symmetry broken (SB) character has been studied by high level multireference variational and full configuration interaction methods. We discuss in great detail the roots of the so-called SB problem and we offer an in depth analysis of the unsuspected reasons behind the double minimum topology found in practically all previous theoretical investigations. We argue that the true reason of failure to recover a D∞h equilibrium geometry lies in the lack of the correct permutational symmetry of the wavefunctions employed and is by no means a real effect. © 2013 AIP Publishing LLC.

Kotzampassi K.,Aristotle University of Thessaloniki | Giamarellos-Bourboulis E.J.,National and Kapodistrian University of Athens | Giamarellos-Bourboulis E.J.,Friedrich - Schiller University of Jena
International Journal of Antimicrobial Agents | Year: 2012

According to current definitions, probiotics are live microorganisms that, when ingested in adequate quantities, exert a health benefit to the host. The action of probiotics in the host is exerted by three mechanisms: modulation of the content of gut microbiota; maintenance of the integrity of the gut barrier and prevention of bacterial translocation; and modulation of the local immune response by the gut-associated immune system. Regarding their role for the prevention and treatment of infectious diseases, adequate evidence coming from randomised clinical trials (RCTs) is available for antibiotic-associated diarrhoea (AAD), Clostridium difficile infection (CDI), acute gastroenteritis and infectious complications following admission to the Intensive Care Unit (ICU). Existing evidence supports their role for decreasing the incidence of AAD and CDI when administered in parallel with antimicrobials. They also shorten the duration of symptoms when administered in paediatric populations with acute gastroenteritis, particularly of rotavirus aetiology. Available evidence is not sufficient to support administration for the management of CDI. Regarding populations of critically ill patients, data from many RCTs suggest a decrease of infectious complications by starting feeding with probiotics following ICU admission, with the exception of patients suffering from severe pancreatitis. However, it should be underscored that all analysed RCTs are characterised by marked heterogeneity regarding the type of administered probiotic species, precluding robust recommendations. © 2012 Elsevier B.V. and the International Society of Chemotherapy. All rights reserved.

Nikolopoulos T.P.,National and Kapodistrian University of Athens
Early Human Development | Year: 2010

Background/Aim: Although already established for metabolic diseases, universal screening programs for hearing have not been widely applied, despite the high incidence of profound congenital hearing loss. The present paper aims to review the current knowledge on the available treatment options for deaf infants. Data synthesis: The acquisition of spoken language is a time-dependent process. For a child to become linguistically competent, some form of linguistic input should be present as early as possible in his/her life. Although objective audiological methods have certain weaknesses, their combination can give an accurate diagnosis in most of the cases. Later on, behavioural audiometry should confirm the diagnosis. Additional disabilities also need to be considered, although such assessments may be difficult in very young children. Congenital deafness should be managed by a multidisciplinary team (MDT). Affected infants should be bilaterally fitted with hearing aids, no later than three months after birth. They should be monitored and if they are not progressing linguistically, cochlear implantation (CI) should be considered after thorough preoperative assessment. Following CI, the vast majority of congenitally deaf children develop significant speech perception and production abilities over time. Age-at-intervention and oral communication, are the most important determinants of outcomes. Realistic parental expectations are also essential. The continuous support of a dedicated pediatric CI program, in collaboration with local professionals, and community members, are also necessary to achieve a successful outcome. Conclusion: Congenitally deaf children should be detected early, and referred timely for the process of auditory rehabilitation to be initiated. Strong support by community members, and professional bodies, can maximize the future earnings of pediatric auditory rehabilitation with hearing aids and cochlear implants. © 2010 Elsevier Ltd.

Mavromichalaki H.,National and Kapodistrian University of Athens
Eos | Year: 2010

Cosmic rays, high-energy particles that reach Earth's atmosphere from outer space, provide a diagnostic tool to analyze processes of general astrophysical interest, such as the acceleration and transport of highly energetic charged particles in interplanetary space and at the Sun. Cosmic rays also directly affect the terrestrial environment and serve as indicators of solar variability and nonanthropogenic climate changes on Earth at present and in the distant past. In the 1950s a worldwide network of standardized cosmic ray detectors was developed to examine temporal and spatial variations in the space environment. Despite decades of progress, ground-based neutron monitors (NMs) remain the state-of-the-art instrumentation for measuring cosmic rays with gigaelectron volt energies, which cannot be measured in the same simple, inexpensive, and statistically accurate way by space experiments. Therefore, the worldwide network, which currently consists of about 50 standardized International Geophysical Year (IGY) and NM64 neutron monitors, perfectly complements cosmic ray observations in space. The continuous monitoring of cosmic ray intensity near Earth by neutron monitors since IGY 1957-1958 represents the longest continuous, high-time-resolution series of particle radiation measurements in space science.

Kioutsioukis I.,Aristotle University of Thessaloniki | Melas D.,Aristotle University of Thessaloniki | Zerefos C.,National and Kapodistrian University of Athens
International Journal of Climatology | Year: 2010

This article focuses on extreme events of high and low temperatures and precipitation and their amplitude and frequency changes over the last 50 years in Greece. Sixteen climate indices have been calculated and their trends were analysed to identify possible changes over a network of measurement stations covering the region quite homogeneously. Furthermore, the changes in the probability distribution of the indices were examined. In addition, we analyzed the temporal evolution of the amplitude and frequency of extreme events through the parameters of extreme value distribution. The temporal stability of the fitted distributions is examined and the spatial distribution of their trend as well as the changes in the 5-year return levels is investigated. Half of the examined climatic indices exhibit significant regional trend; most of them are sole functions of minimum temperature or precipitation. A shift was found in the tail distribution of the peak minimum temperatures, with the 5-year return value in the last quartile of the twientieth century to be equal to the 7-year return value in the previous quartile. Warming was also apparent for the maximum temperature, mainly in the summer months, but of smaller magnitude. Total precipitation shifted towards drier climate over the domain while extreme rainfall events exhibit increased variability without following any coherent regional pattern. The changes in the peak temperature extremes are most sensitive to the changes in the location of the distribution of annual extremes. Changes in the precipitation extremes are associated with changes in both the scale and location of the fitted distribution. The highest range of change was found for the scale parameter for both temperature and precipitation extremes, pointing out that the most influenced factor is the interannual variability of the extremes. © 2009 Royal Meteorological Society.

Georgakopoulou E.A.,National and Kapodistrian University of Athens
Stomatologija / issued by public institution "Odontologijos studija" ... [et al.] | Year: 2011

The number of patients who are long-term survivors of renal transplantation increases rapidly, and proportionally increases the demand of quality dental care for this group of patients. All the transplant patients are on potent immunosupressants and also some of them may suffer from other systemic diseases, so their dental management is a challenge for any dentist. This article is an update of the current relevant literature and is aimed to summarize the key points of dental care for renal transplant patients, since no specific guidelines exist. The research for relevant references took place by using Pubmed database, as well as information published by accredited medical societies and health services both in Greece and abroad.

Ramos-Casals M.,Sjogren Syndrome Research Group AGAUR | Tzioufas A.G.,National and Kapodistrian University of Athens | Stone J.H.,Massachusetts General Hospital | Siso A.,Primary Care Research Group | Bosch X.,Instituto Clinico Of Medicina Y Dermatologia
JAMA - Journal of the American Medical Association | Year: 2010

Context: A variety of topical and systemic drugs are available to treat primary Sjögren syndrome, although no evidence-based therapeutic guidelines are currently available. Objective: To summarize evidence on primary Sjögren syndrome drug therapy from randomized controlled trials. Data Sources: We searched MEDLINE and EMBASE for articles on drug therapy for primary Sjögren syndrome published between January 1, 1986, and April 30, 2010. Study Selection: Controlled trials of topical and systemic drugs including adult patients with primary Sjögren syndrome were selected as the primary information source. Results: The search strategy yielded 37 trials. A placebo-controlled trial found significant improvement in the Schirmer and corneal staining scores, blurred vision, and artificial tear use in patients treated with topical ocular 0.05% cyclosporine. Three placebo-controlled trials found that pilocarpine was associated with improvements in dry mouth (61%-70% vs 24%-31% in the placebo group) and dry eye (42%-53% vs 26%). Two placebo-controlled trials found that cevimeline was associated with improvement in dry mouth (66%-76% vs 35%-37% in the placebo group) and dry eye (39%-72% vs 24%-30%). Small trials (<20 patients) found no significant improvement in sicca outcomes for oral prednisone or hydroxychloroquine and limited benefits for immunosuppressive agents (azathioprine and cyclosporine). A large trial found limited benefits for oral interferon alfa-2a. Two placebo-controlled trials of infliximab and etanercept did not achieve the primary outcome (a composite visual analog scale measuring joint pain, fatigue, and dryness); neither did 2 small trials (<30 patients) testing rituximab, although significant results were observed in some secondary outcomes and improvement compared with baseline. Conclusions: In primary Sjögren syndrome, evidence from controlled trials suggests benefits for pilocarpine and cevimeline for sicca features and topical cyclosporine for moderate or severe dry eye. Anti-tumor necrosis factor agents have not shown clinical efficacy, and larger controlled trials are needed to establish the efficacy of rituximab. ©2010 American Medical Association. All rights reserved.

Duntas L.H.,National and Kapodistrian University of Athens
Journal of Endocrinological Investigation | Year: 2011

Resveratrol, the naturally occurring polyphenolic compound characterized by anti-oxidative, anti-inflammatory and apoptotic properties, appears to contribute substantially to cardioprotection and cancer-prevention. In addition, resveratrol is believed to regulate several biological processes, mainly metabolism and aging, by modulating the mammalian silent information regulator 1 (SIRT1) of the sirtuin family. Resveratrol may arrest, among various tumors, cell growth in both papillary and follicular thyroid cancer by activation of the mitogen-activated protein kinase (MAPK) signal transduction pathway as well as increase of p53 and its phosphorylation. Finally, resveratrol also influences thyroid function by enhancing iodide trapping and, by increasing TSH secretion via activation of sirtuins and the phosphatidylinositol-4-phosphate 5 kinase γ (PIP5Kγ) pathway, positively affects metabolism. ©2011, Editrice Kurtis.

Papacosta E.,Loughborough University | Nassis G.P.,National and Kapodistrian University of Athens
Journal of Science and Medicine in Sport | Year: 2011

Objectives: This paper discusses the use of saliva analysis as a tool for monitoring steroid, peptide, and immune markers of sports training. Design: Salivary gland physiology, regarding the regulation and stimulation of saliva secretion, as well as methodological issues including saliva collection, storage and analysis are addressed in this paper. The effects of exercise on saliva composition are then considered. Method: Exercise elicits changes in salivary levels of steroid hormones, immunoglobulins, antimicrobial proteins and enzymes. Cortisol, testosterone and dehydroepiandrosterone can be assessed in saliva, providing a non-invasive option to assess the catabolic and anabolic effects of exercise. Validation studies using blood and salivary measures of steroid hormones are addressed in this paper. Effects of acute exercise and training on salivary immunoglobulins (SIgA, SIgM, SIgG) and salivary antimicrobial proteins, including α-amylase, lysozyme and lactoferrin, are also discussed. Results: Analysis of cortisol and testosterone in saliva may help detect the onset of non-functional overreaching and subsequently may help to prevent the development of overtraining syndrome. Assessment of salivary immunoglobulins and antimicrobial proteins has been shown to successfully represent the effects of exercise on mucosal immunity. Increases in SIgA and antimicrobial proteins concentration and/or secretion rate are associated with acute exercise whereas conversely, decreases have been reported in athletes over a training season leaving the athlete susceptible for upper respiratory tract infections. Conclusions: The measurement of physiological biomarkers in whole saliva can provide a significant tool for assessing the immunological and endocrinological status associated with exercise and training. © 2011 Sports Medicine Australia.

Dologlou E.,National and Kapodistrian University of Athens
Natural Hazards and Earth System Science | Year: 2010

A possible geophysical mechanism based on the conception of criticality and on new aspects of biological effects caused by electromagnetic fields is discussed as a stimulus to the unusual animal behavior prior to large earthquakes. This mechanism is related to transient electric signals of low frequency and intensity, which are emitted from the pre-focal area several days before the impending earthquake and fulfill all the conditions set by a recent bioeffect model. © 2010 Author(s).

Tektonidou M.G.,National and Kapodistrian University of Athens
Lupus | Year: 2014

Renal involvement in antiphospholipid syndrome (APS), either primary or systemic lupus erythematosus (SLE)-related APS, includes renal artery stenosis or thrombosis, renal infarction, renal vein thrombosis and a small-vessel vaso-occlusive nephropathy defined as "antiphospholipid antibody (aPL)-associated nephropathy." aPL-associated nephropathy is characterized by acute lesions, thrombotic microangiopathy, and chronic lesions such as fibrous intimal hyperplasia, organizing thrombi with or without recanalization, fibrous occlusions of arteries or arterioles and focal cortical atrophy. Systemic hypertension, hematuria, proteinuria (ranging from mild to nephrotic level) and renal insufficiency represent the major clinical manifestations associated with aPL-associated nephropathy. Similar renal histologic and clinical characteristics have been described among all different groups of patients with positive aPL (primary APS, SLE-related APS, catastrophic APS and SLE/non-APS with positive aPL). In patients with aPL-associated nephropathy lesions in the absence of other causes associated with similar histological characteristics, aPL testing needs to be considered. © The Author(s) 2014 Reprints and permissions: sagepub.co.uk/journalsPermissions.nav.

Baxevanis C.N.,Cancer Immunology and Immunotherapy Center | Voutsas I.F.,Cancer Immunology and Immunotherapy Center | Tsitsilonis O.E.,National and Kapodistrian University of Athens
Immunotherapy | Year: 2013

Toll-like receptor (TLR) agonists possess remarkable properties, particularly with regard to dendritic cell activation, promoting Th1-type cytokine production and optimizing cytotoxic T-cell responses. Preclinical and clinical studies conducted to date show that TLR agonists can improve currently applied anticancer vaccination protocols. Although these have resulted in the US FDA approval of three TLR agonists for use in humans, their abundant application encounters limitations, principally due to dose-limiting toxicity evoking from systemic cytokine production. Here, using selected examples of clinical studies, we provide a concise review regarding the knowledge acquired thus far on the adjuvant use of TLR agonists as cancer vaccine components. We also provide evidence on the exploitation of a novel TLR agonist, prothymosin-α, which enhances the efficacy of tumor-reactive effectors without causing severe adverse effects. © 2013 Future Medicine Ltd.

Aims: The aim of this study was to examine (1) the prevalence of overweight and obesity, (2) the relationship between body mass index (BMI) and the percentage of body fat (BF), (3) the relationship between BMI, BF and physical fitness in male soccer players aged 14-16 yrSubjects: Members of soccer clubs (n=171, aged 15.0±0.6years) performed a series of anthropometric, body composition and physical fitness testsResults: Based on international BMI cut-off points, 19.3% (n=33) of participants were classified as overweightBMI was highly correlated with BF (r=0.79, p<0.001) and BF could be predicted based on the equation BF=1.276×BMI -10.94 (standard error of estimate 2.67)BMI and BF were inversely related with aerobic power (r=-0.28, P<0.001; r=-0.41, P<0.001, respectively), maximal anaerobic power (r=-0.29, P<0.001; r=-0.47, P<0.001) and anaerobic endurance (r=-0.24, P=0.002; r=-0.52, P<0.001)Low or non-significant correlations were found between flexibility and BMI (r=0.16, P=0.042) or BF (r=-0.02, P=0.824)Handgrip strength was in inverse relationship with BMI (r=-0.25, P<0.001), as well as with BF (r=-0.38, P<0.001)Arm-swing countermovement vertical jump was also inversely associated with BF (r=-0.27, P<0.01), but not with BMI (r=-0.07, P=0.477)Conclusion: The prevalence of overweight among participants was similar with what is observed in general populationThe strong relationship between BMI and BF, and the acceptable standard error of estimate of the former based on the latter suggest the further use of BMI in adolescent soccer playersThe findings confirmed previous observations on general population about the negative effect of overweight on physical fitness© 2013.

Sismanis A.,National and Kapodistrian University of Athens
Current Opinion in Otolaryngology and Head and Neck Surgery | Year: 2011

Pulsatile tinnitus deserves a thorough evaluation and, in the majority of cases, there is a treatable underlying cause. The possibility of a life-threatening cause needs to be ruled out in every patient with pulsatile tinnitus. The otolaryngologist should be familiar with the evaluation and management of this symptom. © 2011 Wolters Kluwer Health.

Hadjiagapiou I.A.,National and Kapodistrian University of Athens
Physica A: Statistical Mechanics and its Applications | Year: 2013

The spin-1/2 Ising model on a square lattice, with fluctuating bond interactions between nearest neighbors and in the presence of a random magnetic field, is investigated within the framework of the effective field theory based on the use of the differential operator relation. The random field is drawn from the asymmetric and anisotropic bimodal probability distribution P( hi)=pδ(hi-h1)+qδ( hi+ch1), where the site probabilities p,q take on values within the interval [0,1] with the constraint p+q=1; hi is the random field variable with strength h1 and c the competition parameter, which is the ratio of the strength of the random magnetic field in the two principal directions +z and -z; c is considered to be positive resulting in competing random fields. The fluctuating bond is drawn from the symmetric but anisotropic bimodal probability distribution P(Jij)=12δ( Jij-(J+Δ))+δ(Jij-(J-Δ)), where J and Δ represent the average value and standard deviation of Jij, respectively. We estimate the transition temperatures, phase diagrams (for various values of the system's parameters c,p,h1,Δ), susceptibility, and equilibrium equation for magnetization, which is solved in order to determine the magnetization profile with respect to T and h1. © 2012 Elsevier B.V. All rights reserved.

Skordas E.S.,National and Kapodistrian University of Athens
Solid State Ionics | Year: 2010

Very recent measurements of the electrical conductivity of solid systems AgX-CdX2 (where X ≡ Cl, Br) that form large areas of solid solutions, have shown that maximum conductivity occurs for a concentration around 20 mol% of the cadmium halide. Here, we suggest a quantitative explanation of this phenomenon based on a model that was recently suggested (J. Appl. Phys. 103, 083552, (2008)) for estimating the compressibility of multiphased mixed crystals. In addition, explicit conditions are obtained which predict when such a conductivity maximum is expected to occur. © 2010 Elsevier B.V. All rights reserved.

Foukas P.G.,University of Lausanne | Foukas P.G.,National and Kapodistrian University of Athens | de Leval L.,University of Lausanne
Histopathology | Year: 2015

A large variety of lymphoma types may develop as primary intestinal neoplasms in the small intestines or, less often, in the colorectum. Among these are a few entities such as enteropathy-associated T-cell lymphoma or immunoproliferative small intestinal disease that, essentially, do not arise elsewhere than in the gastrointestinal tract. In most instances the primary intestinal lymphomas belong to entities that also occur in lymph nodes or other mucosal sites, and may show some peculiar features. In the case of follicular lymphoma, important differences exist between the classical nodal cases and the intestinal cases, considered as a variant of the disease. It is likely that the local intestinal mucosal microenvironment is a determinant in influencing the pathobiological features of the disease. In this review we will present an update on the clinical, pathological and molecular features of the lymphoid neoplasms that most commonly involve the intestines, incorporating recent developments with respect to their pathobiology and classification. We will emphasize and discuss the major differential diagnostic problems encountered in practice, including the benign reactive or atypical lymphoid hyperplasias, indolent lymphoproliferative disorders of T or natural killer (NK) cells, and Epstein-Barr virus (EBV)-related lymphoproliferations. © 2015 John Wiley & Sons Ltd.

Dalakas M.C.,National and Kapodistrian University of Athens | Dalakas M.C.,Thomas Jefferson University
Therapeutic Advances in Neurological Disorders | Year: 2015

Myasthenia gravis (MG) is an autoimmune disease caused by complement-fixing antibodies against acetylcholine receptors (AChR); antigen-specific CD4+ T cells, regulatory T cells (Tregs) and T helper (Th) 17+ cells are essential in antibody production. Target-specific therapeutic interventions should therefore be directed against antibodies, B cells, complement and molecules associated with T cell signaling. Even though the progress in the immunopathogenesis of the disease probably exceeds any other autoimmune disorder, MG is still treated with traditional drugs or procedures that exert a non-antigen specific immunosuppression or immunomodulation. Novel biological agents currently on the market, directed against the following molecular pathways, are relevant and specific therapeutic targets that can be tested in MG: (a) T cell intracellular signaling molecules, such as anti-CD52, anti-interleukin (IL) 2 receptors, anti- costimulatory molecules, and anti-Janus tyrosine kinases (JAK1, JAK3) that block the intracellular cascade associated with T-cell activation; (b) B cells and their trophic factors, directed against key B-cell molecules; (c) complement C3 or C5, intercepting the destructive effect of complement-fixing antibodies; (d) cytokines and cytokine receptors, such as those targeting IL-6 which promotes antibody production and IL-17, or the p40 subunit of IL-12/1L-23 that affect regulatory T cells; and (e) T and B cell transmigration molecules associated with lymphocyte egress from the lymphoid organs. All drugs against these molecular pathways require testing in controlled trials, although some have already been tried in small case series. Construction of recombinant AChR antibodies that block binding of the pathogenic antibodies, thereby eliminating complement and antibody-depended-cell-mediated cytotoxicity, are additional novel molecular tools that require exploration in experimental MG. © 2015 SAGE Publications.

The aim of the present study was the determination of the levels of osteoprotegerin and soluble RANKL in blood serum and in gingival crevicular fluid relative to the degree of orthodontic root resorption in a rat model. Blood samples and gingival crevicular fluid were collected from fourteen 6-month-old male Wistar rats weighing 350-500 g. A 25-g closed orthodontic coil spring was inserted between each upper right first molar and the upper incisors. After 21 days of loading, both upper first molars (treated and control) were extracted and studied under microcomputed tomography scanning. Statistical analysis demonstrated a positive linear correlation between the initial concentration of RANKL in blood serum and the degree of root resorption. The ratio of the initial concentrations of osteoprotegerin to RANKL in blood serum proved to be an independent prognostic factor of the degree of root resorption. The initial concentration of RANKL in gingival crevicular fluid showed a negative correlation to the initial concentration of RANKL in blood serum and for a finite range of initial concentrations of osteoprotegerin in gingival crevicular fluid, the dental root seemed protected against extreme external root resorption. Finally, the concentration of osteoprotegerin in blood serum decreased significantly in cases of severe root resorption.

Botitsi H.V.,General Chemical State Laboratory | Garbis S.D.,Biomedical Research Foundation of the Academy of Athens BRFAA | Economou A.,National and Kapodistrian University of Athens | Tsipi D.F.,General Chemical State Laboratory
Mass Spectrometry Reviews | Year: 2011

Analysis of pesticides and their metabolites in food and water matrices continues to be an active research area closely related to food safety and environmental issues. This review discusses the most widely applied mass spectrometric (MS) approaches to pesticide residues analysis over the last few years. The main techniques for sample preparation remain solvent extraction and solid-phase extraction. The QuEChERS (Quick, Easy, Cheap, Effective, Rugged, Safe) approach is being increasingly used for the development of multi-class pesticide residues methods in various sample matrices. MS detectors-triple quadrupole (QqQ), ion-trap (IT), quadrupole linear ion trap (QqLIT), time-of-flight (TOF), and quadrupole time-of-flight (QqTOF)-have been established as powerful analytical tools sharing a primary role in the detection/quantification and/or identification/confirmation of pesticides and their metabolites. Recent developments in analytical instrumentation have enabled coupling of ultra-performance liquid chromatography (UPLC) and fast gas chromatography (GC) with MS detectors, and faster analysis for a greater number of pesticides. The newly developed "ambient-ionization" MS techniques (e.g., desorption electrospray ionization, DESI, and direct analysis in real time, DART) hyphenated with high-resolution MS platforms without liquid chromatography separation, and sometimes with minimum pre-treatment, have shown potential for pesticide residue screening. The recently introduced Orbitrap mass spectrometers can provide high resolving power and mass accuracy, to tackle complex analytical problems involved in pesticide residue analysis. © 2010 Wiley Periodicals, Inc.

Diamanti-Kandarakis E.,National and Kapodistrian University of Athens
Best Practice and Research: Clinical Obstetrics and Gynaecology | Year: 2010

Polycystic ovary syndrome (PCOS), a heterogeneous syndrome of unknown aetiology, is the leading cause of anovulation, hirsutism and infertility in women. This multifactorial syndrome emerges at puberty and has cardiovascular and metabolic sequelae through menopause. The common features of normal puberty, namely menstrual irregularities and insulin resistance, obscure the diagnosis of adolescent PCOS, while there are no established diagnostic criteria for PCOS in this age group. The clinical implications of PCOS diagnosis in adolescents remain unclear. Experts in the field still ponder whether PCOS should be managed at such a young age with a view to hindering the long-term sequelae of the syndrome. © 2009 Elsevier Ltd. All rights reserved.

Kino T.,U.S. National Institutes of Health | Chrousos G.P.,National and Kapodistrian University of Athens
Endocrine Development | Year: 2011

Glucocorticoids, the end-products of the hypothalamic-pituitary-adrenal (HPA) axis, influence the functions of virtually all organs and tissues through the nuclear glucocorticoid receptor (GR). Circulating levels of glucocorticoids fluctuate naturally in a circadian fashion under the strong influence of the hypothalamic suprachiasmatic nucleus (SCN) circadian CLOCK system, and regulate the transcriptional activity of the GR in the brain and peripheral target tissues. We recently reported that the basic helix-loop-helix transcription factor Clock, which is a histone acetyltransferase and a central component of the self-oscillating transcription factor loop that generates circadian rhythms, represses GR transcriptional activity by acetylating lysine residues within the 'lysine cluster' located in the hinge region of the receptor. This Clock-mediated repression of GR transcriptional activity oscillates in inverse phase to the HPA axis, acting as a target tissue counter-regulatory mechanism to the diurnally fluctuating circulating glucocorticoids. Interestingly, mild evening elevations of corti-sol, as occurs in chronic stress situations, and frequent uncoupling of the SCN CLOCK-directed HPA axis from the daily oscillation of target tissue sensitivity to glucocorticoids, as happens in trans-time zone travel and night shift work, produce functional hypercortisolism and, hence, multiple components of the metabolic syndrome with resultant cardiovascular complications. Copyright © 2011 S. Karger AG, Basel.

Tiniakos D.G.,National and Kapodistrian University of Athens
European Journal of Gastroenterology and Hepatology | Year: 2010

Nonalcoholic fatty liver disease (NAFLD) is recognized as the most common cause of chronic liver disease in western countries. NAFLD is etiologically associated with systemic and hepatic insulin resistance and is considered by many as the hepatic manifestation of the metabolic syndrome. NAFLD has a wide histological spectrum ranging from 'simple' steatosis to nonalcoholic steatohepatitis (NASH), which may progress to cirrhosis. Hepatocellular carcinoma may occur in NASH-related cirrhosis. The diagnosis of NAFLD/NASH is based on clinico-pathological criteria. Currently available noninvasive tests for the diagnosis of NASH lack specificity and sensitivity, so liver biopsy, despite its limitations, still remains the 'golden standard' for confirming or excluding NASH in a patient with chronically-elevated liver enzymes and image-detected steatosis. This review examines the currently used criteria for the histopathological diagnosis of NAFLD/NASH in adults and children and the relevant histological scoring systems. © 2010 Wolters Kluwer Health | Lippincott.

Alexopoulou A.,National and Kapodistrian University of Athens | Karayiannis P.,University of Nicosia
World Journal of Gastroenterology | Year: 2014

Molecular virology methods including polymerase chain reaction, cloning and sequencing have revolutionised our understanding of viral genome variation. In the case of hepatitis B virus (HBV), sequencing studies have identified a number of virus variants normally found during the natural course of chronic infection. The appearance of the precore stop codon (with G-for-A substitution at position 1896) and basal core promoter (BCP) (with A-for-T and G-for-A, at positions 1762 and 1764, respectively) variants which reduce or abrogate hepatitis B e antigen (HBeAg) production, heralds the initiation of the seroconversion phase from HBeAg to antiHBe positivity. The gradual removal of the tolerogenic effect of HBeAg leads to the awakening of the immune response (immune clearance phase). Most patients after HBeAg seroconversion become "inactive HBsAg carriers". However during the course of infection precore and/or BCP variants may emerge and be selected leading to HBeAg negative chronic hepatitis B (CHB) with high viremia levels (reactivation phase). The prevalence of HBeAg negative CHB has been increasing over the last few decades and has become the commonest type of HBV infection in many countries of the world. This probably reflects the aging of existing HBV carriers and the effective prevention measures restricting new HBV infections. Frequent acute exacerbations accompanied by high viral replication, elevated alanine aminotransferase levels and histological activity are a common feature of HBeAg negative CHB leading to cirrhosis much faster than in HBeAg positive CHB patients. © 2014 Baishideng Publishing Group Inc. All rights reserved.

A cheap and fast construction of both enantiomers of substituted succinimides is reported. α- or β-amino acids, such as β-phenylalanine and α-tert-butyl aspartate, were found to be efficient organocatalysts for the reaction between α,α-disubstituted aldehydes and maleimides. Products containing contiguous quaternary-tertiary stereogenic centers are obtained in high to quantitative yields and excellent selectivities utilizing low catalyst loadings (0.5-3.5%). Finally, a one-pot efficient asymmetric synthesis of lactones is described. © 2013 American Chemical Society.

Petrou A.L.,National and Kapodistrian University of Athens
Chemical Geology | Year: 2012

By studying the Free Energy of Activation, δG ≠, of various geochemical transformations we have revealed the importance of the contribution of the entropy of activation, δS ≠, in the energetics of the processes. In studies performed so far including changes of phases, adsorption, desorption, formation or breaking of bonds, ordering of ions, etc. only the activation energy was considered as the main factor determining the rate of the transformation process through the Arrhenius equation. The above changes result in change of degrees of freedom of the systems. If the above changes happen during the "reactants to transition state or activated complex" step, they result in changes of the entropy of activation. Through the use of the Eyring-Polanyi equation and literature data we were able to determine δG ≠=δH ≠-TδS ≠ where δH ≠ is related to E act=RT+δΗ ≠ and δS ≠ is related to A of the Arrhenius equation. It was found that the combination of enthalpy and entropy of activation in δG ≠ gives a more realistic/true value of the energy requirements of the activation step that the processes need in order to take place. Also, an explanation is given of why calculated activation energy values (that are related only to enthalpy of activation values) for certain transformations deviate from the expected and observed energy requirements that characterize the processes when the entropic component is substantial. This analysis shows that similar processes have similar δG ≠ values and therefore there is a way of foreseeing the δG ≠ of a process, if a number of similar processes have been studied and their δG ≠ values have been calculated. © 2012 Elsevier B.V.

Vossos S.,National and Kapodistrian University of Athens
Epitheorese Klinikes Farmakologias kai Farmakokinetikes | Year: 2014

Choosing real space-time for the unmoved observer (O), all the natural sizes are real, too. Vossos Matrix expresses closed Linear Space-time Transformation, which maintains Space-time distance S2. This Matrix contains real and imaginary numbers, so the space becomes complex for moving observer (Ó), but time remains real. Generally for moving observers, fourvectors' zero component (such as energy) is real, in contrast with space-components that are complex, but their norm is real. We prove that moving relative to (O) human (Ó) meter length, according to Lorentz Transformation. In addition, we find rotation Matrix Vossos- Lorentz that turns natural sizes' complex components to real. We also prove that speed of light is invariant, when complex components are used and Vossos Transformation is closed for three sequential observers. After, we find out the connection between two moving relative to (O) observers: X́́= ΛÓ́(Ï) ΛLO(Ï ́) ×́. We applied this theory, finding relations between natural sizes, that are the same as these extracted by classic relativity, when two observers are related (i.e. relativistic Doppler shift is the same). But, the results are different, when more than two observers are related.

Lunemann J.D.,University of Zurich | Nimmerjahn F.,Friedrich - Alexander - University, Erlangen - Nuremberg | Dalakas M.C.,National and Kapodistrian University of Athens
Nature Reviews Neurology | Year: 2015

Intravenous immunoglobulin (IVIg)-a preparation of polyclonal serum IgG pooled from thousands of blood donors-has been used for nearly three decades, and is proving to be an efficient anti-inflammatory and immunomodulatory treatment for a growing number of neurological diseases. Evidence from controlled clinical trials has established IVIg as a first-line therapy for Guillain-Barré syndrome, chronic inflammatory demyelinating polyneuropathy and multifocal motor neuropathy. IVIg is also an effective rescue therapy in some patients with worsening myasthenia gravis, and is beneficial as a second-line therapy for dermatomyositis and stiff-person syndrome. IVIg has been tested in some neurodegenerative disorders, but a controlled study in Alzheimer disease yielded disappointing results. Despite its widespread use and therapeutic success, the mechanisms of action of IVIg are poorly understood. Several hypotheses, based on the function of either the variable or constant IgG fragments, have been proposed to explain IVIg's immunomodulatory activity. This Review highlights emerging data on the mechanisms of action of IVIg related to its anti-inflammatory activity, especially that involving the cellular FcÎ 3 receptors and Fc glycosylation. We also summarize recent trials in neurological diseases, discuss potential biomarkers of efficacy, offer practical guidelines on administration, and provide a rationale for experimental trials in neuroinflammatory disorders. © 2015 Macmillan Publishers Limited.

Levidou G.,National and Kapodistrian University of Athens
Diagnostic pathology | Year: 2010

BACKGROUND: Gliomas are a very rare subtype of pineal region tumours, whereas oligodendrogliomas of the pineal region are exceedingly rare, since there have been only 3 cases of anaplastic oligodedrogliomas reported this far. METHODS-RESULTS: We present a case of a low-grade oligodendroglioma arising in the pineal gland of a 37 year-old woman. The patient presented with diplopia associated with a cystic pineal region mass demonstrated on MRI. Total resection was performed and histological examination showed that the cystic wall consisted of tumour cells with a central nucleus a perinuclear halo and minimal pleomorphism. Immnunohistochemical analysis showed that these cells were diffusely positive for CD57, and negative for GFAP, CD10, CD99, cytokeratins, neurofilaments and synaptophysin. FISH analysis was performed in a small number of neoplastic cells, which were not exhausted after immunohistochemistry and did not reveal deletion of 1p and 19q chromosome arms. However, the diagnosis of a low grade oligodendroglioma of the pineal gland was assigned. CONCLUSION: Although the spectrum of tumours arising in the pineal gland is broad, the reports of oligodendrogliomas confined to this location are exceedingly rare, and to the best of our knowledge there is no report of a low-grade oligodendroglioma. However, they should be added in the long list of tumours arising in the pineal gland.

Karavalakis G.,National Technical University of Athens | Bakeas E.,National and Kapodistrian University of Athens | Stournas S.,National Technical University of Athens
Environmental Science and Technology | Year: 2010

This paper investigates the effects of biodiesel blends on regulated and unregulated emissions from a Euro 4 diesel passenger car, fitted with a diesel oxidation catalyst and a diesel particle filter (DPF). Emission and fuel consumption measurements were conducted for the New European Driving Cycle (NEDC) and the Artemis driving cycles. Criteria pollutants, along with carbonyl, polycyclic aromatic hydrocarbon (PAH) and nitrate PAH and oxygenate PAH emissions, were measured and recorded. A soy-based biodiesel and an oxidized biodiesel, obtained from used frying oils, were blended with an ultra low sulfur diesel at proportions of 20, 30, and 50% by volume. The results showed that the DPF had the ability to significantly reduce particulate matter (PM) emissions over all driving conditions. Carbon monoxide (CO) and hydrocarbon (HC) emissions were also reduced with biodiesel; however, a notable increase in nitrogen oxide (NO x) emissions was observed with biodiesel blends. Carbon dioxide (CO 2) emissions and fuel consumption followed similar patterns and increased with biodiesel. The influence of fuel type and properties was particularly noticeable on the unregulated pollutants. The use of the oxidized biodiesel blends led to significant increases in carbonyl emissions, especially in compounds which are associated with potential health risks such as formaldehyde, acetaldehyde, and acrolein. Sharp increases in most PAH compounds and especially those which are known for their toxic and carcinogenic potency were observed with the oxidized blends. The presence of polymerization products and cyclic acids were the main factors that influenced the PAH emissions profile. © 2010 American Chemical Society.

Dologlou E.,National and Kapodistrian University of Athens
Natural Hazards and Earth System Science | Year: 2010

The credibility of the power law relation, reported by Dologlou (2009) between the stress drop of an earthquake and the lead time of the preceded Seismic Electric Signal, SES, has been checked through additional new data from 9 June 2008 to 7 April 2010. Three earthquakes with Mw≥5.5 have been found in Greece during this period. A critical exponent α (e.g. 0.328) has been obtained which compares very well with the one reported (αCombining double low line0.332) by Dologlou (2009). The stability of this exponent might imply that critical dynamic processes, of mechanical (earthquakes) and also of electromagnetic (SES) sense dominate the pre focal area when the SES signal of the impending earthquake is emitted. © 2010 Author(s).

Megremi I.,National and Kapodistrian University of Athens
Central European Journal of Geosciences | Year: 2010

Plants and soils from central Euboea, were analyzed for Cr (total), Cr(VI), Ni, Mn, Fe and Zn. The range of metal concentrations in soils is typical to those developed on Fe-Ni laterites and ultramafic rocks. Their bioavailability was expressed in terms of concentrations extractable with EDTA and 1 M HNO3, with EDTA having a limited effect on metal recovery. Cr(VI) concentrations in soils evaluated by alkaline digestion solution were lower than phytotoxic levels.Chromium and Ni - and occasionally Zn - in the majority of plants were near or above toxicity levels. Cr(VI) concentrations in plants were extremely low compared to total chromium concentrations.Cr(total) in ground waters ranged from <1 μg.L-1 to 130 μg.L-1, with almost all chromium present as Cr(VI). With the exception of Cr(total) and in some cases Zn, all elements were below regulatory limits for drinking water. On the basis of Ca, Mg, Cr(total) and Si ground waters were classified into three groups: Group(I) with Cr concentrations less than 1 μg.L-1 from a karstic aquifer; Group(II) with average concentrations of 24 μg.L -1 of Cr and relatively high Si associated with ophiolites; and Group(III) with Cr concentrations of up to 130 μg.L-1, likely due to anthropogenic activity. Group(III) is comparable to ground waters from Assopos basin, characterized by high Cr(VI) concentrations, probably due to industrial actrivities. © Versita Warsaw.

Lekkas E.L.,National and Kapodistrian University of Athens
Bulletin of the Seismological Society of America | Year: 2010

The Wenchuan earthquake of 12 May 2008 in Sichuan Province, China, can be classified as a large-scale event based on the tectonic structures that triggered the earthquake and the effects caused on the human, structural, and natural environment. This paper presents the geotectonic and seismotectonic regime of the earthquakeaffected region on the basis of field data obtained along the seismic fault zone and provides: (1) an estimation of the intensity values according to the EMS-98 and the ESI 2007 scales and the determination of their large-scale geographical distribution along the causative tectonic structure, (2) an interpretation of the intensity distribution according to the seismotectonic, geodynamic, and geotechnical framework, and (3) a comparison between two different intensity scales, the EMS-98 (which is essentially based on the effects on the built environment) and the ESI 2007 (which is based on earthquake environmental effects). The application of both EMS-98 and ESI 2007 and the comparative review and evaluation of the results indicate that the estimated values of the EMS-98 and the ESI 2007 were similar. This suggests that both scales can be useful and reliable tools for seismic hazard estimation.

Kaitelidou D.,National and Kapodistrian University of Athens
International Journal of Health Services | Year: 2012

Planning of the workforce has emerged as a critical issue in European health policy, as the need for human resources for health is changing in light of demographic, epidemiological, and socio-cultural trends and patterns of supply and demand in service provision. Greece represents a country with an oversupply of physicians, having the highest concentration of physicians among European Union countries. The study aims to analyze the factors influencing the high number of physicians in Greece and make policy recommendations. The analysis was conducted through international literature review and database searches. Neither the demography of the physician population in terms of age, gender composition, and geographic dispersion, nor the epidemiology of the Greek population, can explain the relatively high number of physicians in Greece. Despite the physician surplus, Greece faces serious geographical inequities regarding the distribution of physicians. There are also imbalances within the specialist category, with certain specialists (e.g., cardiologists) being in oversupply compared to other European countries, while others (e.g., general practitioners) remain weakly represented. Inadequate planning of human resources for health, inadequate health financing policy regarding primary care, gatekeeping mechanisms, and medical power constitute the primary themes explaining the trends of physicians' population in Greece. © 2012, Baywood Publishing Co., Inc.

Dalakas M.C.,National and Kapodistrian University of Athens | Dalakas M.C.,Thomas Jefferson University
Biochimica et Biophysica Acta - Molecular Basis of Disease | Year: 2015

Autoimmune neuropathies occur when immunologic tolerance to myelin or axonal antigens is lost. Even though the triggering factors and the underling immunopathology have not been fully elucidated in all neuropathy subsets, immunological studies on the patients' nerves, transfer experiments with the patients' serum or intraneural injections, and molecular fingerprinting on circulating autoantibodies or autoreactive T cells, indicate that cellular and humoral factors, either independently or in concert with each other, play a fundamental role in their cause. The review is focused on the main subtypes of autoimmune neuropathies, mainly the Guillain-Barré syndrome(s), the Chronic Inflammatory Demyelinating Polyneuropathy (CIDP), the Multifocal Motor Neuropathy (MMN), and the IgM anti-MAG-antibody mediated neuropathy. It addresses the factors associated with breaking tolerance, examines the T cell activation process including co-stimulatory molecules and key cytokines, and discusses the role of antibodies against peripheral nerve glycolipids or glycoproteins. Special attention is given to the newly identified proteins in the nodal, paranodal and juxtaparanodal regions as potential antigenic targets that could best explain conduction failure and rapid recovery. New biological agents against T cells, cytokines, B cells, transmigration and transduction molecules involved in their immunopathologic network, are discussed as future therapeutic options in difficult cases. This article is part of a Special Issue entitled: Neuromuscular Diseases: Pathology and Molecular Pathogenesis. © 2014 Elsevier B.V.

Cantner K.,University of Rhode Island | Carey S.,University of Rhode Island | Nomikou P.,National and Kapodistrian University of Athens
Journal of Volcanology and Geothermal Research | Year: 2014

Kolumbo submarine volcano, located 7. km northeast of Santorini, Greece in the Aegean Sea, last erupted in 1650. AD. Submarine and subaerial explosive activity lasted for a period of about four months and led to the formation of thick (~ 250 m) highly stratified pumice deposits on the upper crater walls as well as extensive pumice rafts that were dispersed throughout the southern Aegean Sea. Subaerial tephra fallout from eruption columns that breached the surface occurred as far east as Turkey.Remotely operated vehicle (ROV) video observations from transects of the northern and southwestern crater walls have been used to create stratigraphic sequences of the 1650AD deposits. Petrographic and geochemical analyses reveal that the bulk of the deposits consists of white, highly vesicular, sparsely porphyritic, biotite-bearing rhyolite pumice. Pre-eruption volatile contents determined from plagioclase-hosted melt inclusions yield a median value of 6.5wt.%. This corresponds to a pre-eruption storage pressure of ~200MPa, or a depth of ~6km assuming a H2O-saturated magma. Comparison of the natural glass compositions and mineral assemblage of the Kolumbo samples with experimental results on other rhyolite magmas of similar composition in the modified haplogranite system supports the pressure and total volatile estimates. Pre-eruption temperature was calculated as 750°C based on plagioclase-melt geothermometry.The high volatile content of the Kolumbo magma and historical accounts of substantial subaerial eruption plumes suggest that the explosive eruption was driven by primary volatile degassing. Three phases of activity can be inferred from historical accounts and deposit stratigraphy; an initial submarine eruption during which time the vent became shallower as pyroclastic material accumulated, a transitional phase with substantial fallout from a hybrid submarine/subaerial eruption plume, and a final subaqueous phase as the eruption waned. Depositional processes included a complex interplay of submarine fallout, pyroclastic density currents, and clast segregation associated with the transition from submarine to subaerial plumes, producing a highly stratified pumiceous sequence. This is the first study of the in situ pyroclastic deposits of a well-documented silicic submarine explosive eruption in the relatively shallow (<. 500. m below sea level) marine environment. © 2013 Elsevier B.V.

Diallinas G.,National and Kapodistrian University of Athens
Biochimie | Year: 2013

In Aspergillus nidulans UapA is a H+-driven transporter specific for xanthine, uric acid and several analogues. Here, genetic and physiological evidence is provided showing that allopurinol is a high-affinity, low-capacity, substrate for UapA. Surprisingly however, transport kinetic measurements showed that, uniquely among all recognized UapA substrates, allopurinol is transported by apparent facilitated diffusion and exhibits a paradoxical effect on the transport of physiological substrates. Specifically, excess xanthine or other UapA substrates inhibit allopurinol uptake, as expected, but the presence of excess allopurinol results in a concentration-dependent enhancement of xanthine binding and transport. Flexible docking approaches failed to detect allopurinol binding in the major UapA substrate binding site, which was recently identified by mutational analysis and substrate docking using all other UapA substrates. These results and genetic evidence suggest that the allopurinol translocation pathway is distinct from, but probably overlapping with, that of physiological UapA substrates. Furthermore, although the stimulating effect of allopurinol on xanthine transport could, in principle, be rationalized by a cryptic allopurinol-specific allosteric site, evidence was obtained supporting that accelerated influx of xanthine is triggered through exchange with cytoplasmically accumulated allopurinol. Our results are in line with recently accumulating evidence revealing atypical and complex mechanisms underlying transport systems. © 2013 Elsevier Masson SAS. All rights reserved..

Koutrika G.,Stanford University | Ioannidis Y.,National and Kapodistrian University of Athens
ACM Transactions on Database Systems | Year: 2010

People's preferences are expressed at varying levels of granularity and detail as a result of partial or imperfect knowledge. One may have some preference for a general class of entities, for example, liking comedies, and another one for a fine-grained, specific class, such as disliking recent thrillers with Al Pacino. In this article, we are interested in capturing such complex, multi-granular preferences for personalizing database queries and in studying their impact on query results. We organize the collection of one's preferences in a preference network (a directed acyclic graph), where each node refers to a subclass of the entities that its parent refers to, and whenever they both apply, more specific preferences override more generic ones. We study query personalization based on networks of preferences and provide efficient algorithms for identifying relevant preferences, modifying queries accordingly, and processing personalized queries. Finally, we present results of both synthetic and real-user experiments, which: (a) demonstrate the efficiency of our algorithms, (b) provide insight as to the appropriateness of the proposed preference model, and (c) show the benefits of query personalization based on composite preferences compared to simpler preference representations. © 2010 ACM.

Mitrakou A.,National and Kapodistrian University of Athens
Diabetes Research and Clinical Practice | Year: 2011

According to current textbook wisdom the liver is the exclusive site of glucose production in humans in the postabsorptive state. Although animal and in vitro studies have documented that the kidney is capable of gluconeogenesis, glucose production by the human kidney has been regarded as negligible. This knowledge is based on net balance measurements across the kidney. Recent studies combining isotopic and balance techniques have demonstrated that the human kidney is involved in the regulation of glucose homeostasis by making glucose via gluconeogenesis, taking up glucose from the circulation, and by reabsorbing glucose from the glomerular filtrate. The human liver and kidneys release approximately equal amounts of glucose via gluconeogenesis in the postabsorptive state. In the postprandial state, although overall endogenous glucose release decreases substantially, renal gluconeogenesis actually increases by approximately 2-fold. Following meal ingestion, glucose utilization by the kidney increases. Increased glucose uptake into the kidney may be implicated in diabetic nephropathy. Normally each day, ∼180 g of glucose is filtered by the kidneys; almost all of this is reabsorbed by means of sodium glucose cotransporter 2 (SGLT2), expressed in the proximal tubules. However, the capacity of SGLT2 to reabsorb glucose from the renal tubules is finite and when plasma glucose concentrations exceed a threshold, glucose begins to appear in the urine. Renal glucose release is stimulated by epinephrine and is inhibited by insulin. Handling of glucose by the kidney is altered in type 2 diabetes mellitus (T2DM): renal gluconeogenesis and renal glucose uptake are increased in both the postabsorptive and postprandial states, and renal glucose reabsorption is also increased Since renal glucose release is almost exclusively due to gluconeogenesis, it seems that the kidney is as important gluconeogenic organ as the liver. The most important renal gluconeogenic precursors appear to be lactae glutamine and glycerol. © 2011 Elsevier Ireland Ltd.

Sachanas S.,National and Kapodistrian University of Athens
Leukemia & lymphoma | Year: 2011

The optimal treatment approach for patients with mantle cell lymphoma (MCL) is not well defined. Intensive therapeutic regimens result in high response rates and prolonged progression-free survival but at the expense of significant toxicity. We report here our results of the administration of rituximab plus chlorambucil (R-Chl) as first line treatment in patients with MCL. Twenty consecutively diagnosed patients were treated with this combination in which an induction and a maintenance arm were included. During induction, rituximab was administered at a dose of 375 mg/m(2) on day 1, while chlorambucil was given afterward at a dose of 10 mg/day for 10 consecutive days for eight cycles and then as a single agent for an additional four cycles. Maintenance consisted of rituximab administration every 2 months for 1 year. Most patients had indolent disease features such as a low mantle-cell international prognostic index (MIPI) score. The overall response rate was 95% (90% CR, 5% PR). Among patients in CR, 78% presented a molecular remission. The 3-year progression-free survival was 89%. There were no serious side effects. These results show that the R-Chl combination could be an effective therapeutic option as first line treatment in MCL, especially for patients with indolent disease characteristics.

Papageorgiou E.A.,Cyprus Institute of Neurology and Genetics | Karagrigoriou A.,University of Cyprus | Tsaliki E.,Cyprus Institute of Neurology and Genetics | Tsaliki E.,National and Kapodistrian University of Athens | And 3 more authors.
Nature Medicine | Year: 2011

The trials performed worldwide toward noninvasive prenatal diagnosis (NIPD) of Down's syndrome (or trisomy 21) have shown the commercial and medical potential of NIPD compared to the currently used invasive prenatal diagnostic procedures. Extensive investigation of methylation differences between the mother and the fetus has led to the identification of differentially methylated regions (DMRs). In this study, we present a strategy using the methylated DNA immunoprecipitation (MeDiP) methodology in combination with real-time quantitative PCR (qPCR) to achieve fetal chromosome dosage assessment, which can be performed noninvasively through the analysis of fetal-specific DMRs. We achieved noninvasive prenatal detection of trisomy 21 by determining the methylation ratio of normal and trisomy 21 cases for each tested fetal-specific DMR present in maternal peripheral blood, followed by further statistical analysis. The application of this fetal-specific methylation ratio approach provided correct diagnosis of 14 trisomy 21 and 26 normal cases. © 2011 Nature America, Inc. All rights reserved.

Chang M.-L.,Chang Gung University | Liaw Y.-F.,Chang Gung University | Hadziyannis S.J.,National and Kapodistrian University of Athens
Alimentary Pharmacology and Therapeutics | Year: 2015

Background It has been debated whether finite nucleos(t)ide analogue therapy is feasible in HBeAg-negative chronic hepatitis B. Aim To review this issue systematically. Methods Using text terms HBsAg and various nucleos(t)ide analogues, PubMed was searched between 1995 and 2014 to find studies on therapy >6 months in adult HBeAg-negative chronic hepatitis B patients with off-therapy follow-up >6 months. Results Twenty-two studies with a total of 1732 patients were identified and included. The median duration of therapy, consolidation therapy and off-therapy follow-up ranged from 6 months to 8 years, 4 to 96 weeks and 6 to 80 months respectively. Patients were monitored with serum ALT and HBV DNA monthly in the first 1-3 months and every 3-6 months afterwards in most studies. The 1-year off-therapy 'virological relapse' (HBV DNA >2000 IU/mL) and 'clinical relapse' (HBV DNA > 2000 IU/mL + ALT elevation) occurred in <70% and <50% of the patients, respectively, and <40% of the patients received re-treatment. These rates were higher in patients with shorter treatment, shorter consolidation therapy and those treated with less potent nucleos(t)ide analogues. Off-therapy severe flares were rare and hepatic decompensation was reported in only one patient with cirrhosis. Biochemical relapse reflecting enhanced immune-mediated hepatocyte killing may lead to a higher chance for off-therapy HBsAg seroclearance and be possibly desirable. Conclusion With an appropriate stopping rule and a proper off-therapy monitoring plan, cessation of long-term nucleos(t)ide analogue therapy prior to HBsAg seroclearance in HBeAg-negative chronic hepatitis B is a feasible alternative to indefinite treatment. © 2015 John Wiley & Sons Ltd.

Gaki G.S.,Hellenic Pasteur Institute | Papavassiliou A.G.,National and Kapodistrian University of Athens
NeuroMolecular Medicine | Year: 2014

Parkinson's disease is the second most common neurodegenerative movement disorder; however, its etiology remains elusive. Nevertheless, in vivo observations have concluded that oxidative stress is one of the most common causes in the pathogenesis of Parkinson's disease. It is known that mitochondria play a crucial role in reactive oxygen species-mediated pathways, and several gene products that associate with mitochondrial function are the subject of Parkinson's disease research. The PTEN-induced kinase 1 (PINK1) protects cells from mitochondrial dysfunction and is linked to the autosomal recessive familial form of the disease. PINK1 is a key player in many signaling pathways engaged in mitophagy, apoptosis, or microglial inflammatory response and is induced by oxidative stress. Several proteins participate in mitochondrial networks, and they are associated with PINK1. The E3 ubiquitin ligase Parkin, the protease presenilin-associated rhomboid-like serine protease, the tyrosine kinase c-Abl, the protein kinase MARK2, the protease HtrA2, and the tumor necrosis factor receptor-associated protein 1 (TRAP1) provide different steps of control in protection against oxidative stress. Furthermore, environmental toxins, such as 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine, have been identified as contributors to parkinsonism by increasing oxidative stress in dopaminergic neurons. The present review discusses the mechanisms and effects of oxidative stress, the emerging concept of the impact of environmental toxins, and a possible neuroprotective role of the antioxidant astaxanthin in various neurodegenerative disorders with particular emphasis in Parkinson's disease. © 2014 Springer Science+Business Media New York.

Charmandari E.,National and Kapodistrian University of Athens | Charmandari E.,Biomedical Research Foundation of the Academy of Athens
Science Signaling | Year: 2012

Primary generalized glucocorticoid resistance (PGR or Chrousos syndrome) and primary generalized glucocorticoid hypersensitivity (PGH) are rare genetic disorders characterized by generalized, partial target-tissue insensitivity or hypersensitivity to glucocorticoids, respectively, while also causing compensatory alterations in the activity of the hypothalamic-pituitary-adrenal axis. The molecular basis of Chrousos syndrome and PGH has been ascribed to mutations in the gene encoding the human glucocorticoid receptor (hGR), which impair glucocorticoid signal transduction and alter tissue sensitivity to glucocorticoids. Alterations in hGR action may have important implications for many critical biological processes, such as the behavioral and physiologic responses to stress, immune responses, growth, and reproduction. This Presentation summarizes the pathophysiology, clinical manifestations, and molecular mechanisms of the PGR and PGH states.

Varotsos C.A.,National and Kapodistrian University of Athens | Zellner R.,University of Duisburg - Essen
Atmospheric Chemistry and Physics | Year: 2010

To elaborate stratospheric ozone depletion processes, measurements of diffusion coefficients of selected gas phase molecules (i.e. HCl, CH 3OH, HCOOH and CH3COOH; Katsambas et al., 1997; Kondratyev and Varotsos, 1996; Varotsos et al., 1994, 1995) in ice in the temperature range 170-195 K have been analyzed with respect to the mechanisms and rates of diffusion. It is argued that the diffusion in ice of these compounds is governed by a vacancy-mediated mechanism, i.e. H2O vacancies are required to diffuse to lattice sites adjacent to these compounds prior to the diffusion of the corresponding molecule into the vacancy sites. In addition, we show that the diffusion coefficients of these compounds exhibit a specific interconnection, i.e. a linear relationship holds between the logarithm of the pre-exponential factor, Do, and the activation energy E. The physical meaning of this interconnection is discussed.

Giaginis C.,National and Kapodistrian University of Athens
Medical science monitor : international medical journal of experimental and clinical research | Year: 2011

DNA repair is a major defense mechanism, which contributes to the maintenance of genetic sequence, and minimizes cell death, mutation rates, replication errors, DNA damage persistence and genomic instability. Alterations in the expression levels of proteins participating in DNA repair mechanisms have been associated with several aspects of cancer biology. The present study aimed to evaluate the clinical significance of DNA repair proteins MSH2, MLH1 and MGMT in benign and malignant thyroid lesions. MSH2, MLH1 and MGMT protein expression was assessed immunohistochemically on paraffin-embedded thyroid tissues from 90 patients with benign and malignant lesions. The expression levels of MLH1 was significantly upregulated in cases with malignant compared to those with benign thyroid lesions (p = 0.038). The expression levels of MGMT was significantly downregulated in malignant compared to benign thyroid lesions (p = 0.001). Similar associations for both MLH1 and MGMT between cases with papillary carcinoma and hyperplastic nodules were also noted (p = 0.014 and p = 0.026, respectively). In the subgroup of malignant thyroid lesions, MSH2 downregulation was significantly associated with larger tumor size (p = 0.031), while MLH1 upregulation was significantly associated with the presence of lymphatic and vascular invasion (p = 0.006 and p = 0.002, respectively). Alterations in the mismatch repair proteins MSH2 and MLH1 and the direct repair protein MGMT may result from tumor development and/or progression. Further studies are recommended to draw definite conclusions on the clinical significance of DNA repair proteins in thyroid neoplasia.

Hadjiagapiou I.A.,National and Kapodistrian University of Athens
Physica A: Statistical Mechanics and its Applications | Year: 2012

The Ising model in the presence of a random field, drawn from the asymmetric and anisotropic trimodal probability distribution P( hi)=pδ( hi- h0)+qδ( hi+λ* h0)+rδ( hi), is investigated. The partial probabilities p,q,r take on values within the interval [0,1] consistent with the constraint p+q+r=1; asymmetric distribution, hi is the random field variable with basic absolute value h0 (strength); λ is the competition parameter, which is the ratio between the respective strength of the random magnetic field in the two principal directions (+z) and (-z) and is positive so that the random fields are competing, anisotropic distribution. This probability distribution is an extension of the bimodal one allowing for the existence in the lattice of non magnetic particles or vacant sites. The current random field Ising system displays mainly second order phase transitions, which, for some values of p,q and h0, are followed by first order phase transitions joined smoothly by a tricritical point; occasionally, two tricritical points appear implying another second order phase transition. In addition to these points, re-entrant phenomena can be seen for appropriate ranges of the temperature and random field for specific values of λ, p and q. Using the variational principle, we write down the equilibrium equation for the magnetization and solve it for both phase transitions and at the tricritical point in order to determine the magnetization profile with respect to h0, considered as an independent variable in addition to the temperature. © 2012 Elsevier B.V. All rights reserved.

Januzzi J.L.,Massachusetts General Hospital | Filippatos G.,National and Kapodistrian University of Athens | Nieminen M.,University of Helsinki | Gheorghiade M.,Northwestern University
European Heart Journal | Year: 2012

Cardiac troponin testing is commonly performed in patients with heart failure (HF). Despite being strongly linked to spontaneous (Type I) acute myocardial infarction (MI)a common cause of acute HF syndromesit is well recognized that concentrations of circulating troponins above the 99th percentile of a normal population in the context of both acute and chronic HF are highly prevalent, and frequently unrelated to Type I MI. Other mechanism(s) leading to troponin elevation in HF syndromes remain elusive in many cases but prominently includes supplydemand inequity (Type II MI), which may be associated with coronary artery obstruction and endothelial dysfunction, or may occur in the absence of coronary obstruction due to increased oxygen demand related to increased wall tension, anaemia, or other factors provoking subendocardial injury. Non-coronary triggers, such as cellular necrosis, apoptosis, or autophagy in the context of wall stress may explain the troponin release in HF, as can toxic effects of circulating neurohormones, toxins, inflammation, and infiltrative processes, among others. Nonetheless, across a wide spectrum of HF syndromes, when troponin elevation occurs, independent of mechanism, it is strongly predictive of an adverse outcome. Clinicians should be aware of the high frequency of troponin elevation when measuring the marker in patients with HF, should keep in mind the possible causes of this phenomenon, and, independent of a diagnosis of 'acute MI', should recognize the considerable ramifications of troponin elevation in this setting. © 2011 The Author.

Tarhini A.A.,University of Pittsburgh | Gogas H.,National and Kapodistrian University of Athens | Kirkwood J.M.,University of Pittsburgh
Journal of Immunology | Year: 2012

Among the IFNs, IFN-α2 has been the most broadly evaluated clinically. At the molecular level, IFN-α has multiple effects in a variety of malignancies that range from antiangiogenic to potent immunoregulatory, differentiation-inducing, antiproliferative, and proapoptotic effects. A multitude of IFN-α2 regimens that may be classified as low dose, intermediate dose, and high dose have been evaluated as adjuvant therapy in melanoma. A durable impact on both relapse-free and overall survival was seen only with the regimen utilizing high-dose IFN-α2b tested in the Eastern Cooperative Oncology Group and intergroup trials E1684, E1690, and E1694 as adjuvant therapy for high-risk surgically resected melanoma (stage IIB or III). Adjuvant pegylated IFN-α2b has also been evaluated at maximally tolerable doses compared with the observation group in the European Organization for Research and Treatment of Cancer trial 18991 and has shown relapse-free survival benefits in patients with microscopic nodal disease. Copyright © 2012 by The American Association of Immunologists, Inc.

Voskaridou E.,Thalassaemia Center | Christoulas D.,251 General Airforce Hospital | Terpos E.,National and Kapodistrian University of Athens
British Journal of Haematology | Year: 2012

Sickle cell disease (SCD) is an inherited chronic haemolytic anaemia whose clinical manifestations arise from the tendency of the haemoglobin to polymerize and deform red blood cells into the characteristic sickle shape due to a single nucleotide change in the β-globin. Vascular occlusion of small and large vessels can lead to chronic damage of multiple organs including brain, lung, bone, kidney, liver, spleen, and retina. However, the extent to which SCD impacts myocardial function is not very clear. Cardiovascular manifestations include both right and left ventricular systolic and diastolic dysfunction, elevated cardiac output, cardiomegaly and myocardial ischaemia. Progressive heart damage from iron overload occurs in patients requiring routine transfusion therapy. Pulmonary hypertension resulting from intravascular haemolysis has also been recognized as a major complication that independently correlates with survival. This review summarizes all available data for the heart complications in SCD to update the physicians for their appearance, diagnostic procedures and possible management. © 2012 Blackwell Publishing Ltd.

Economopoulos K.P.,National and Kapodistrian University of Athens
International journal of gynecological cancer : official journal of the International Gynecological Cancer Society | Year: 2010

A debate exists about whether glutathione S-transferase (GST) polymorphisms (GST mu-1 [GSTM1] null/present genotype and GST theta-1 [GSTT1] null/present genotype) confer additional risk for cervical cancer. This meta-analysis was aimed to examine the associations between the aforementioned polymorphisms and cervical cancer risk. Thirteen studies were eligible for GSTM1 (1616 cervical cancer cases and 1970 controls), and 12 studies were eligible for GSTT1 (1393 cases and 1766 controls). Pooled odds ratios (OR) were appropriately derived from fixed effects or random effects models. Separate analyses were conducted on Chinese and non-Chinese populations. Metaregression with publication year was also performed. At the overall analysis, the GSTM1 null genotype was associated with increased cervical cancer risk (pooled OR = 1.272; 95% confidence interval [CI], 1.014-1.597, random effects). The association seemed confined to non-Chinese populations (pooled OR = 1.392; 95% CI, 1.003-1.932, random effects) given that the association was not significant in the subset of Chinese studies (pooled OR = 1.080; 95% CI, 0.870-1.340, fixed effects). On the other hand, at the overall analysis, the GSTT1 null genotype was not associated with increased cervical cancer risk (pooled OR = 1.301; 95% CI, 0.948-1.787, random effects). Similarly, no significant associations were detected in either non-Chinese or Chinese populations concerning the GSTT1 null genotype. The GSTM1 null genotype confers additional risk for cervical cancer in non-Chinese populations. The trend concerning GSTT1 has not reached significance.

Kondi-Pafiti A.,National and Kapodistrian University of Athens
Archives of gynecology and obstetrics | Year: 2011

To present the clinicopathological features of metastatic ovarian neoplasms with emphasis in the diagnostic challenge. This is a retrospective study including 97 patients with pathological diagnosis of metastatic ovarian neoplasms, examined during the decade 2000-2009. The gross, microscopical and immunohistochemical characteristics as well as the clinical data (age of the patients, origin of the neoplasm, symptoms, treatment options) and 5-year survival rates were examined. The mean age of the patients is 55 years (range 26-78 years). 62.89% of the tumors were metastatic from extragenital organs (from stomach 21.65%, breast 15.46%, colon 15.46%, appendix 3.09%, pancreas 2.06%, lung 1.03% and kidney 1.03%, sarcoma 1.03% melanoma 1.03%) and 37.11% tumors originated from the genital tract. The 3-year survival rates ranged from 25.39% for metastatic ovarian neoplasms originating outside the genital tract up to 29.41% for those originating from the genital tract. Tumor immunohistochemistry is a helpful aid in the differential diagnosis mainly between primary mucinous ovarian tumors and metastatic colon cancers and in the recognition of metastatic breast cancers and other neoplasms of the GI tract. The management of metastatic ovarian neoplasms should include specific immunohistochemical methods in order to identify the primary neoplasm site. The differential diagnosis of a pelvic mass should always include metastatic neoplasms of the ovaries.

Traeger-Synodinos J.,National and Kapodistrian University of Athens