Instituto Superior Of Ciencias Da Saude Egas Moniz

Charneca, Portugal

Instituto Superior Of Ciencias Da Saude Egas Moniz

Charneca, Portugal
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Diogenes M.J.,University of Lisbon | Dias R.B.,University of Lisbon | Rombo D.M.,University of Lisbon | Vicente Miranda H.,University of Lisbon | And 14 more authors.
Journal of Neuroscience | Year: 2012

Parkinson's disease (PD) is the most common representative of a group of disorders known as synucleinopathies, in which misfolding and aggregation of α-synuclein (a-syn) in various brain regions is themajorpathological hallmark. Indeed, themotorsymptomsinPDare causedby a heterogeneous degeneration of brain neurons not only in substantia nigra pars compacta but also in other extrastriatal areas of the brain. In addition to the well known motor dysfunction in PD patients, cognitive deficits and memory impairment are also an important part of the disorder, probably due to disruption of synaptic transmission and plasticity in extrastriatal areas, including the hippocampus. Here, we investigated the impact of a-syn aggregation onAMPAandNMDAreceptor-mediated rat hippocampal (CA3-CA1) synaptic transmission and long-term potentiation (LTP), the neurophysiological basis for learning and memory. Our data show that prolonged exposure to a-syn oligomers, but not monomers or fibrils, increases basal synaptic transmission through NMDA receptor activation, triggering enhanced contribution of calcium-permeable AMPA receptors. Slices treated with a-syn oligomers were unable to respond with further potentiation to theta-burst stimulation, leading to impaired LTP. Prior delivery of a low-frequency train reinstated the ability to express LTP, implying that exposuretoa-synoligomersdrivestheincreaseofglutamatergicsynaptictransmission,preventingfurtherpotentiationbyphysiologicalstimuli. Our novel findings provide mechanistic insight on how a-syn oligomers may trigger neuronal dysfunction and toxicity in PD and other synucleinopathies. © 2012 the authors.

Gago S.,New University of Lisbon | Basilio N.,New University of Lisbon | Quintas A.,Instituto Superior Of Ciencias Da Saude Egas Moniz | Pina F.,New University of Lisbon
Journal of Agricultural and Food Chemistry | Year: 2017

The effect of β-cyclodextrin on the mole fraction distribution of the multistate species of the anthocyanin model compound, 3-methoxy-4′,7-dihydroxyflavylium, was studied by NMR, stopped flow, circular dichroism, and UV-visible absorption spectroscopy. The formation of inclusion complexes with hemiketal and trans-chalcone, possessing transition dipole moments in a parallel orientation to the cyclodextrin n-fold axis, was unequivocally proved by means of the positive-induced circular dichroism signal. The discrimination of the two hemiketal enantiomers was achieved by the splitting of 1H NMR peaks in the presence β-cyclodextrin. The spectroscopic data shows that the β-cyclodextrin has only moderate enantioselectivity, slightly favoring one of the optical isomers. The observed binding affinity of β-cyclodextrin for the 3-methoxy-4′,7-dihydroxyflavylium multistate species increases in the order flavylium cation < quinoidal base < hemiketal < trans-chalcone < cis-chalcone. As a result of this selectivity and the dynamic nature of the network, the equilibrium is displaced toward the formation of the chalcone species. © 2017 American Chemical Society.

Ferreira A.F.,University of Lisbon | Ortigueira J.,National Laboratory of Energy and Geology | Alves L.,National Laboratory of Energy and Geology | Gouveia L.,National Laboratory of Energy and Geology | And 3 more authors.
Bioresource Technology | Year: 2013

This paper presents a life cycle inventory of biohydrogen production by Clostridium butyricum through the fermentation of the whole Scenedesmus obliquus biomass. The main purpose of this work was to determine the energy consumption and CO2 emissions during the production of hydrogen. This was accomplished through the fermentation of the microalgal biomass cultivated in an outdoor raceway pond and the preparation of the inoculum and culture media. The scale-up scenarios are discussed aiming for a potential application to a fuel cell hybrid taxi fleet.The H2 yield obtained was 7.3gH2/kg of S. obliquus dried biomass. The results show that the production of biohydrogen required 71-100MJ/MJH2 and emitted about 5-6kgCO2/MJH2. Other studies and production technologies were taken into account to discuss an eventual process scale-up. Increased production rates of microalgal biomass and biohydrogen are necessary for bioH2 to become competitive with conventional production pathways. © 2013 Elsevier Ltd.

Ferreira A.F.,University of Lisbon | Ortigueira J.,National Laboratory of Energy and Geology | Alves L.,National Laboratory of Energy and Geology | Gouveia L.,National Laboratory of Energy and Geology | And 3 more authors.
Biomass and Bioenergy | Year: 2013

This paper presents the life cycle inventory (LCI) of hydrogen production by Clostridium butyricum fermentation of Scenedesmus obliquus hydrolysate. The main purpose of this work was to evaluate the potential of H2 production from microalgal biomass and the respective energy consumption and CO2 emissions in the bioconversion process considering the microalga production, acid hydrolysis of S. obliquus biomass, preparation of the inoculum and culture media, and fermentation. The scale-up to industrial production was not envisaged.The hydrogen yield obtained in this work was 2.9 ± 0.3 mol H2/mol sugars in S. obliquus hydrolysate. Results show that this process of biological production of hydrogen can achieve 7270 MJ/MJH2 of energy consumption and 670 kgCO2/MJH2. The microalgal culture is the stage responsible for 98% of these total final values due to the use of artificial lighting. All stages and processes with the highest values of energy consumption and CO2 emissions were identified for future energetic and environmental optimisation. © 2012 Elsevier Ltd.

Mendes J.J.,Hospital Of Santa Marta | Marques-Costa A.,Podiatry Outpatient Clinic | Vilela C.,University of Lisbon | Neves J.,Hospital Of Santo Antonio Dos Capuchos | And 3 more authors.
Diabetes Research and Clinical Practice | Year: 2012

Aims: An epidemiological survey of diabetic foot infections (DFIs) in Lisbon, stratifying the bacterial profile based on patient demographical data, diabetic foot characteristics (PEDIS classification), ulcer duration and antibiotic therapy. Methods: A transversal observational multicenter study, with clinical data collection using a structured questionnaire and microbiological products (aspirates, biopsies or swabs collected using the Levine method) of clinically infected foot ulcers of patients with diabetes mellitus (DM). Results: Forty-nine hospitalized and ambulatory patients were enrolled in this study, and 147 microbial isolates were cultured. Staphylococcus was the main genus identified, and methicillin-resistant Staphylococcus aureus (MRSA) was present in 24.5% of total cases. In the clinical samples collected from patients undergoing antibiotic therapy, 93% of the antibiotic regimens were considered inadequate based on the antibiotic susceptibility test results. The average duration of an ulcer with any isolated multi-drug resistant (MDR) organism was 29 days, and previous treatment with fluoroquinolones was statistically associated with multi-drug resistance. Conclusions: Staphylococcus aureus was the most common cause of DFIs in our area. Prevalence and precocity of MDR organisms, namely MRSA, were high and were probably related to previous indiscriminate antibiotic use. Clinicians should avoid fluoroquinolones and more frequently consider the use of empirical anti-MRSA therapy. © 2011 Elsevier Ireland Ltd.

Mascarenhas P.,Instituto Superior Of Ciencias Da Saude Egas Moniz | Fatela B.,Centro Hospitalar Of Setubal Chs | Barahona I.,Instituto Superior Of Ciencias Da Saude Egas Moniz
PLoS ONE | Year: 2014

Background: Early screening of type 2 diabetes mellitus (DM) is essential for improved prognosis and effective delay of clinical complications. However, testing for high glycemia often requires invasive and painful blood testing, limiting its large-scale applicability. We have combined new, unpublished data with published data comparing salivary glucose levels in type 2 DM patients and controls and/or looked at the correlation between salivary glucose and glycemia/HbA1c to systematically review the effectiveness of salivary glucose to estimate glycemia and HbA1c. We further discuss salivary glucose as a biomarker for large-scale screening of diabetes or developing type 2 DM. Methods and Findings: We conducted a meta-analysis of peer-reviewed published articles that reported data regarding mean salivary glucose levels and/or correlation between salivary glucose levels and glycemia or HbA1c for type 2 DM and non-diabetic individuals and combined them with our own unpublished results. Our global meta-analysis of standardized mean differences on salivary glucose levels shows an overall large positive effect of type 2 DM over salivary glucose (Hedge's g = 1.37). The global correlation coefficient (r) between salivary glucose and glycemia was large (r = 0.49), with subgroups ranging from medium (r = 0.30 in non-diabetics) to very large (r = 0.67 in diabetics). Meta-analysis of the global correlation between salivary glucose and HbA1c showed an overall association of medium strength (r = 0.37). Conclusions: Our systematic review reports an overall meaningful salivary glucose concentration increase in type 2 DM and a significant overall relationship between salivary glucose concentration and associated glycemia/HbA1c values, with the strength of the correlation increasing for higher glycemia/HbA1c values. These results support the potential of salivary glucose levels as a biomarker for type 2 DM, providing a less painful/invasive method for screening type 2 DM, as well as for monitoring blood glucose levels in large cohorts of DM patients. © 2014 Mascarenhas et al.

da Silva M.S.,New University of Lisbon | Vao E.R.,New University of Lisbon | Temtem M.,New University of Lisbon | Mafra L.,University of Aveiro | And 4 more authors.
Biosensors and Bioelectronics | Year: 2010

Molecularly imprinted polymers (MIPs) of poly(ethylene glycol dimethacrylate) and poly(Nisopropylacrylamide- co-ethylene glycol dimethacrylate) were synthesized for the first time in supercritical carbon dioxide (scCO2), using Boc-l-tryptophan as template. Supercritical fluid technology provides a clean and one-step synthetic route for the preparation of affinity polymeric materials with sensing capability for specific molecules. The polymeric materials were tested as stationary HPLC phases for the enantiomeric separation of l- and d-tryptophan. HPLC results prove that the synthesized MIPs are able to recognize the template molecule towards its enantiomer which opens up potential applications in chromatographic chiral separation. © 2009 Elsevier B.V.

Gavara R.,New University of Lisbon | Petrov V.,New University of Lisbon | Quintas A.,Instituto Superior Of Ciencias Da Saude Egas Moniz | Pina F.,New University of Lisbon
Phytochemistry | Year: 2013

Self-association constants for the flavylium cations of the six most common anthocyanidin 3-glucosides were determined by circular dichroism (CD) and UV-Vis spectroscopy. Along with previous 1H NMR results, all measurements were consistent with a monomer-dimer model. The CD spectra of the anthocyanidin 3-glucosides were similar to the analogues 3,5-diglucosides. All dimers of the anthocyanidin 3-glucosides exhibited left-handed CD signals, with petunidin-3-glucoside and myrtillin having the most intense signals. In addition, the magnitude of the molar ellipticity, [θ], was generally higher for the 3-glucosides than for the 3,5-diglucosides. For all six anthocyanins studied, the CD absorption spectra of their dimers showed evidence of the splitting of the monomer absorption into lower (J aggregates) and higher (H aggregates) energy bands. The angle and the distance between the dipolar moments of the two monomers comprising the dimer were obtained from the lower energy absorption band. While the angle was more or less similar in all six dimers, the separation distance between the monomer dipole moments differed dramatically. The intensity of the CD signal displayed a linear dependence with the inverse square of the dipole moment distances. © 2013 Elsevier B.V. All rights reserved.

Barros M.T.,New University of Lisbon | Petrova K.T.,New University of Lisbon | Correia-Da-Silva P.,New University of Lisbon | Correia-Da-Silva P.,Instituto Superior Of Ciencias Da Saude Egas Moniz | Potewar T.M.,New University of Lisbon
Green Chemistry | Year: 2011

The chemistry of sucrose is very challenging due to its eight hydroxyl groups, three of which are primary, with very similar reactivities, thus control of the chemoselectivity is a central issue. In this work, the selective formation of monounsaturated esters at the 6-position, by applying the Mitsunobu conditions for the selective esterification of sucrose, is reported. Also, the outcome of a number of mono-substitution reactions at positions 6 or 6′, and di-substitution reactions at positions 6 and 6′ have been explored. Mild and energy-efficient procedures, with short reaction times (5 to 10 min) using microwave irradiation have been developed, and the results compared with conventional procedures. In some cases, the use of microwave irradiation appeared to provide not only time saving but also improved selectivity. © 2011 The Royal Society of Chemistry.

Fonseca J.,Hospital Garcia Of Orta | Fonseca J.,Instituto Superior Of Ciencias Da Saude Egas Moniz | Santos C.A.,Hospital Garcia Of Orta
Acta Medica Portuguesa | Year: 2013

Introduction: Patients suffering from long standing dysphagia need tube feeding through gastrostomy. Nutritional assessment of these patients is challenging and must be supported on objective data, including anthropometric evaluation. Aim: The aim of this study was the evaluation of the usefulness of anthropometry for identifying and grading malnutrition, as part of the initial assessment of patients that underwent endoscopic gastrostomy. Material and Methods: From the files of consecutive adults underwent gastrostomy we selected patients with anthropometric data obtained before the procedure: Body Mass Index, Mid Upper Arm Circumference, Triceps Skinfold Thickness and Mid Arm Muscle Circumference. Nutritional status was classified according with World Health Organization criteria for Body Mass Index, and for Mid Upper Arm Circumference, Triceps Skinfold Thickness and Mid Arm Muscle Circumference using comparison with Frisancho reference-tables. Results: Were selected 367 patients (median of ages: 74.1 years): neurological disease: 172; head and neck cancer: 176; other diseases: 19. Body Mass Index identified 136 underweight and 231 eutrophic or overweight patients. Mid Upper Arm Circumference identified 310 malnourished and 57 eutrophic or overweight patients. Triceps Skinfold Thickness identified 301 malnourished and 66 eutrophic or overweight patients. Mid Arm Muscle Circumference identified 269 malnourished, 97 eutrophic and one with MAMC above normal. Discussion and Conclusions: Anthropometry identified the malnourished endoscopic gastrostomy-patients, contributed for malnutrition grading and demonstrated the impact on muscle and fat reserves. Mid Upper Arm Circumference, Triceps Skinfold Thickness and Mid Arm Muscle Circumference identified malnutrition in nearly 80% of the patients, most clearly with fat tissue wasting than muscle. Easily accessible e inexpensive, anthropometry allowed personalized nutritional therapy. Anthropometry must be recognized as a fundamental tool for enteral feeding teams. © Ordem dos Médicos 2013.

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