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Andrikopoulou M.,Aretaieion Hospital | Chatzistamou I.,National and Kapodistrian University of Athens | Gkilas H.,National and Kapodistrian University of Athens | Vilaras G.,National and Kapodistrian University of Athens | Sklavounou A.,National and Kapodistrian University of Athens
Journal of Oral and Maxillofacial Surgery | Year: 2013

Purpose: Oral pregnancy tumors (OPTs) arise on the inflamed gingiva of women after the first trimester of pregnancy. The expression of angiogenic markers and female hormone receptors was assessed. Materials and Methods: Immunohistochemistry was used to analyze the expression of estrogen and progesterone receptors and the expression of angiogenic factors, such as vascular endothelial growth factor (VEGF) and its receptor, fibroblast growth factor (FGF), and hypoxia inducible factors 1α and 3α (HIF1α and HIF3α). Experimental groups included 9 OPTs, 10 oral pyogenic granulomas from nonpregnant women of the same age, and 9 oral pyogenic granulomas from postmenopausal women. Results: VEGF expression in stromal histiocytes and endothelial cells of small vessels was positively correlated in the OPT group (P <.05 by χ2 test). VEGF receptor also was overexpressed in stromal histiocytes and endothelial cells of OPTs compared with oral pyogenic granulomas from nonpregnant and postmenopausal women (P <.005 by χ2 test). No correlation was detected among estrogen and progesterone receptors, FGF and HIF1α and HIF3α (ER and PgR respectively) in the 3 experimental groups. Conclusions: VEGF-associated angiogenesis is most likely involved in the pathogenesis of the lesion. These results imply that local inhibition of VEGF activity could be an adjuvant therapeutic approach for OPTs to control hemorrhage, which can be massive at the surgical excision of such lesions during pregnancy. © 2013 American Association of Oral and Maxillofacial Surgeons.


Politou M.,Aretaieion Hospital | Boti S.,Laikon Hospital | Androutsakos T.,Laikon Hospital | Valsami S.,Aretaieion Hospital | And 2 more authors.
Journal of Medical Virology | Year: 2015

HEV infection is an emerging public health problem worldwide Data concerning HEV infection in HIV+ patients in Greece is scare. The aim of the study was to determine HEV seroprevalence in patients with HIV infection in Greece. We studied 243 HIV(+) patients 214 men (88%) and 29 women (12%) with a median age of 45 years (range 19-83) who attended the HIV unit of Pathophysiology Department of Laikon General Hospital in Athens for the presence of anti-HEV IgG antibodies with (EIA) (EIA HEV IgG, Adaltis, Rome, Italy Eighteen/243 patients (7.3%) were positive for HEV IgG antibodies, a seroprevalence that was not different from that described for the blood donors group from Greece There was no difference of the presence of HbsAg, hepatitis C and hepatitis A between the HEV(+) and HEV(-) patients. There was no statistically significant difference between the HEV(+) and HEV(-) group in terms of HIV acquisition, sexual orientation, median duration of HIV infection, ART treatment, or duration of ART. Only the median age of HEV(+) was 52years (35-78) while that of HEV(-) was 44years (19-83)(P=0.03). Only 2/18(11.1%) HEV(+) HIV(+) patients had abnormal ALT and AST values. The seroprevalence of hepatitis E in HIV(+) patients in Greece seems to be the same with that of the general population thus implying that HIV infection is not a risk factor for HEV infection and only age shows a positive correlation with seropositivity. © 2015 Wiley Periodicals, Inc.


Papaconstantinou I.G.,Aretaieion Hospital | Lykoudis P.M.,Aretaieion Hospital | Gazouli M.,National and Kapodistrian University of Athens | Manta A.,Aretaieion Hospital | And 2 more authors.
Pancreas | Year: 2012

Objectives: MicroRNAs are molecules implicated in RNA-RNA interaction, playing a role in cell proliferation and differentiation, as well as in carcinogenesis. Knowledge on their biological features is necessary to understand their role in phenotypic characteristics of pancreatic adenocarcinoma. Methods: Review of current literature concerning mechanisms of action, studying methods, implementations, and preclinical trials on pancreatic adenocarcinoma. Results: More than 20 microRNAs have been identified, being involved in pancreatic adenocarcinoma biology, affecting tumor growth, metastatic potential, and chemosensitivity. Combinations of microRNAs can be used to differentiate between pancreatic adenocarcinoma and other pancreatic pathologies, as well as to assess prognosis. Manipulations of microRNAs can decrease the rate of growth or reinstall chemosensitivity to certain chemotherapeutic agents. Conclusions: The field of microRNAs promises novel diagnostic and therapeutic tools in the management of pancreatic adenocarcinoma. Copyright © 2012 by Lippincott Williams & Wilkins.


Papaconstantinou I.G.,Aretaieion Hospital | Manta A.,Aretaieion Hospital | Gazouli M.,National and Kapodistrian University of Athens | Lyberopoulou A.,National and Kapodistrian University of Athens | And 4 more authors.
Pancreas | Year: 2013

OBJECTIVES: Investigation of expression profile of well-established microRNAs in pancreatic adenocarcinoma, and its correlation with clinicopathological factors. METHODS: Eighty-eight samples of ductal pancreatic adenocarcinoma and 98 control samples were analyzed by real-time polymerase chain reaction for miR-21, miR-31, miR-122, miR-145, miR-146a, miR-155, miR-210, and miR-222 expressions. The results were normalized and then statistically analyzed using nonparametric statistical tests. RESULTS: According to our results, miR-21, miR-155, miR-210, miR-221, and miR-222, were overexpressed in diseased tissues than in the control samples, whereas miR-31, miR-122, miR-145, and miR-146a were underexpressed. Additionally, the expressions of miR-21 and miR-155 were associated with tumor stage and poor prognosis. CONCLUSIONS: The tumorigenic role of miR-21 and miR-155 was confirmed, whereas down-regulation of miR-31, miR-145, and miR-146a, in dispute with current literature, renders necessary the revision of use of microRNAs as biological markers. Copyright © 2012 by Lippincott Williams & Wilkins.


Papaconstantinou I.,Aretaieion Hospital | Karakatsanis A.,Aretaieion Hospital | Gazouli M.,National and Kapodistrian University of Athens | Polymeneas G.,Aretaieion Hospital | Voros D.,Aretaieion Hospital
European Journal of Gastroenterology and Hepatology | Year: 2012

Hepatocellular carcinoma and cholangiocarcinoma constitute the majority of primary malignant tumors located in the liver, with hepatocellular carcinoma accounting for approximately 80% of these tumors and cholangiocarcinoma representing the remaining 20%. Both are aggressive malignancies, heterogeneous in terms of biological activities and clinical behavior, with dismal outcomes and an increasing incidence worldwide. Radical surgical resection remains the gold standard to date, as adjuvant therapeutic modalities have failed to show a consistent and adequate curative response. However, radical surgical resection is not feasible in most of the patients with such tumors, as tumor size or functional status of the parenchyma does not permit extended hepatic resection. In addition, patients who undergo curative resection often have a high rate of relapse. Multimodal therapeutic approaches, such as the combination of invasive methods (surgical resection, radiofrequency ablation, and two-step or three-step procedures with intermittent portal vein embolization) with interferon-α, systemic chemotherapy, or transarterial catheter embolization, may prolong survival in some patients, but have, however, failed to demonstrate satisfactory results. Therefore, an obvious need emerges for the discovery of new biomarkers to understand the events leading to hepatocarcinogenesis, to relate different phenotypes with differences in clinical behavior and prognosis, and, if possible, to predict response rates to adjuvant therapeutic modalities or, furthermore, to establish novel mechanism-based treatments for hepatic tumors. © 2012 Wolters Kluwer Health | Lippincott Williams & Wilkins.


Iakovidis D.K.,Technological Educational Institute of Lamia | Tsevas S.,Technological Educational Institute of Lamia | Tsevas S.,University of Geneva | Polydorou A.,Aretaieion Hospital
Computerized Medical Imaging and Graphics | Year: 2010

The screening of the small intestine has become painless and easy with wireless capsule endoscopy (WCE) that is a revolutionary, relatively non-invasive imaging technique performed by a wireless swallowable endoscopic capsule transmitting thousands of video frames per examination. The average time required for the visual inspection of a full 8-h WCE video ranges from 45 to 120. min, depending on the experience of the examiner. In this paper, we propose a novel approach to WCE reading time reduction by unsupervised mining of video frames. The proposed methodology is based on a data reduction algorithm which is applied according to a novel scheme for the extraction of representative video frames from a full length WCE video. It can be used either as a video summarization or as a video bookmarking tool, providing the comparative advantage of being general, unbounded by the finiteness of a training set. The number of frames extracted is controlled by a parameter that can be tuned automatically. Comprehensive experiments on real WCE videos indicate that a significant reduction in the reading times is feasible. In the case of the WCE videos used this reduction reached 85% without any loss of abnormalities. © 2009 Elsevier Ltd.


Lazaridis K.,Hellenic Pasteur Institute | Evaggelakou P.,Hellenic Pasteur Institute | Bentenidi E.,Hellenic Pasteur Institute | Sideri A.,Hellenic Pasteur Institute | And 3 more authors.
Journal of Neuroimmunology | Year: 2015

Myasthenia gravis (MG) is usually caused by antibodies against the muscle acetylcholine receptor (AChR). Plasmapheresis and immunoadsorption are often used to treat non-responsive patients. Antigen-specific immunoadsorption would remove only the pathogenic autoantibodies reducing side-effects. We expressed AChR extracellular domain mutants for use as specific adsorbents, and characterized them. Antigenicity and capacity for autoantibody binding were improved compared to the wild-type proteins. Adsorption appeared to be fast, as high plasma flow-rates could be applied. The bound autoantibodies were eluted repeatedly, allowing column reuse, without compromise in efficiency. Overall, the adsorbents were specific, efficient and suitable for use in therapy. © 2014 Elsevier B.V.


Gennatas C.,Aretaieion Hospital | Michalaki V.,Aretaieion Hospital | Michalaki V.,Greece Areteion Hospital | Vasilatou Kairi P.,Areteion Hospital | And 2 more authors.
World Journal of Surgical Oncology | Year: 2012

Perivascular epithelioid cell tumor (PEComa) is an extremely rare neoplasm that appears to arise most commonly at visceral (especially gastrointestinal and uterine), retroperitoneal, and abdominopelvic sites. Malignant PEComas exist but are very rare. These tumors represent a family of mesenchymal neoplasms, mechanistically linked through activation of the mTOR signaling pathway. Metastatic PEComa is a rare form of sarcoma for which no effective therapy has been described previously and that has a uniformly fatal outcome. Although there is no known effective therapy, the molecular pathophysiology of aberrant mTOR signaling provides a scientific rationale to target this pathway therapeutically. The difficulty in determining optimal therapy, owing to the sparse literature available, led us to present this case. On this basis, we report a case of metastatic retroperitoneal PEComa treated with an oral mTOR inhibitor, with everolimus achieving significant clinical response. © 2012 Gennatas et al.; licensee BioMed Central Ltd.


Karamanolis G.P.,Aretaieion Hospital | Tutuian R.,University of Bern
Annals of Gastroenterology | Year: 2013

Non-erosive reflux disease (NERD) is the most common presentation of gastroesophageal reflux disease. Although acid reflux is the most important cause of symptom generation in NERD patients, non-acid reflux is also associated with reflux symptoms. The temporal relation between symptoms and reflux episodes is of importance in evaluating the results of combined pH-impedance monitoring in NERD patients. Mucosal hypersensitivity and mechanical stimulation due to great volume of non-acid reflux are among the putative mechanisms of symptom generation. © 2013 Hellenic Society of Gastroenterology.


Karamanolis G.P.,Aretaieion Hospital | Sifrim D.,Queen Mary, University of London
Annals of Gastroenterology | Year: 2013

Patients with refractory to proton pump inhibitors (PPIs) gastroesophageal reflux disease (GERD) symptoms are approximately 40% and represent a very common problem in clinical practice. Many of these patients do not have GERD, but suffer from functional heartburn or hypersensitive esophagus. After thorough clinical evaluation and failure of escalation of PPI dose, diagnostic investigations include endoscopy, esophageal manometry, pH testing, esophageal Bilitec and esophageal impedance with pH monitoring. © 2013 Hellenic Society of Gastroenterology.

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