ESSLei - Artigos em revistas internacionais
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- European Respiratory Society International Congress 2021: highlights from best-abstract awardeesPublication . Ramakrishnan, Sanjay; Beaufils, Fabien; De Brandt, Jana; Viney, Kerri; Bradley, Claire; Cottin, Vincent; Hassan, Maged; Cruz, JoanaEvery year, the European Respiratory Society (ERS) offers grants to recognise the best overall abstracts of the 14 ERS Assemblies submitted for the ERS International Congress, covering all respiratory areas. The authors of the best abstract (i.e. the highest average score of abstract reviewers and only those who have not applied or were not eligible for a sponsored award) were invited to write a short summary about their virtual Congress experience and view on the evolving field of research in light of their respective Assembly. This article provides an overview of some of the Congress highlights and gives the stage to the promising best-abstract awardees as they are the future of the ERS.
- Tetramer Dissociation and Monomer Partial Unfolding Precedes Protofibril Formation in Amyloidogenic Transthyretin VariantsPublication . Quintas, Alexandre; Vaz, Daniela C.; Cardoso, Isabel; Saraiva, Maria João M.; Brito, Rui M. M.Amyloid fibril formation and deposition is a common feature of a wide range of fatal diseases including spongiform encephalopathies, Alzheimer's disease, and familial amyloidotic polyneuropathies (FAP), among many others. In certain forms of FAP, the amyloid fibrils are mostly constituted by variants of transthyretin (TTR), a homotetrameric plasma protein. Recently, we showed that transthyretin in solution may undergo dissociation to a non-native monomer, even under close to physiological conditions of temperature, pH, ionic strength, and protein concentration. We also showed that this non-native monomer is a compact structure, does not behave as a molten globule, and may lead to the formation of partially unfolded monomeric species and high molecular mass soluble aggregates (Quintas, A., Saraiva, M. J. M., and Brito, R. M. M. (1999) J. Biol. Chem. 274, 32943–32949). Here, based on aging experiments of tetrameric TTR and chemically induced protein unfolding experiments of the non-native monomeric forms, we show that tetramer dissociation and partial unfolding of the monomer precedes amyloid fibril formation. We also show that TTR variants with the least thermodynamically stable non-native monomer produce the largest amount of partially unfolded monomeric species and soluble aggregates under conditions that are close to physiological. Additionally, the soluble aggregates formed by the amyloidogenic TTR variants showed morphological and thioflavin-T fluorescence properties characteristic of amyloid. These results allowed us to conclude that amyloid fibril formation by some TTR variants might be triggered by tetramer dissociation to a compact non-native monomer with low conformational stability, which originates partially unfolded monomeric species with a high tendency for ordered aggregation into amyloid fibrils. Thus, partial unfolding and conformational fluctuations of molecular species with marginal thermodynamic stability may play a crucial role on amyloid formationin vivo.
- Enthalpic and entropic contributions mediate the role of disulfide bonds on the conformational stability of Interleukin-4Publication . Vaz, Daniela C.; Rodrigues, J. Rui; Sebald, Walter; Dobson, Christopher M.; Brito, Rui M. M.The role of disulfide bridges in the structure, stability, and folding pathways of proteins has been the subject of wide interest in the fields of protein design and engineering. However, the relative importance of entropic and enthalpic contributions for the stabilization of proteins provided by disulfides is not always clear. Here, we perform a detailed analysis of the role of disulfidesin the conformational stability of human Interleukin-4 (IL4), a four-helix bundle protein. In order to evaluate the contribution of two out of the three disulfides to the structure and stability of IL4, two IL4 mutants, C3T-IL4 and C24T-IL4, were used. NMR and ANS binding experiments were compatible with altered dynamics and an increase of the nonpolar solventaccessible surface area of the folded state of the mutant proteins. Chemical and thermal unfolding experiments followed by fluorescence and circular dichroism revealed that both mutant proteins have lower conformational stability than the wild-type protein. Transition temperatures of unfolding decreased 14C for C3T-IL4 and 10C for C24T-IL4, when compared toWT-IL4, and the conformational stability, at 25C, decreased 4.9 kcal/mol for C3T-IL4 and 3.2 kcal/mol for C24T-IL4. Interestingly, both the enthalpy and the entropy of unfolding, at the transition temperature, decreased in the mutant proteins. Moreover, a smaller change in heat capacity of unfolding was also observed for the mutants. Thus, disulfide bridges in IL4 play a critical role in maintaining the thermodynamic stability and core packing of the helix bundle.
- Atitudes e conhecimentos dos educadores sobre mau trato infantilPublication . Catarino, Helena
- O método psicodramático na psicoprofilaxia da amamentaçãoPublication . Ramalho, Sónia
- Health practices and behaviours of studentsPublication . Dixe, Maria dos Anjos; Gaspar, Pedro; Monteiro, Baltazar Ricardo; Lopes, António JoséAims: To determine the practices and behaviours determinants of health among students; to determine the prevalence of eating disorders in a non-clinic population of students and to determine some predicting factors of the health practices and behaviours of students Methodology: A Cross sectional correlational study was conducted. The population for this study was composed of 1442 students who filled a questionnaire composed of: sociodemographic and family data, health practices and behaviours and diagnostic criteria for eating disorders; and general health data Results: The majority of students perceive health as good. As to the prevalence rate of hypercholesterolemia, girls registered a higher rate than boys (p<0,05) Identical results were found for the abdominal perimeter, with girls presenting a higher coronary risk when this parameter is present. The prevalence rate of pre-obesity and obesity is higher among male students. The results demonstrate differences according to gender which suggest that girls have healthier practices, eating and sleeping habits, driving behaviours and physical activity than boys. Older students have healthier eating and physical activity behaviours than younger students. The health practices and behaviours of students do not rely on the fact of them having all their meals at home. No potential cases of anorexia or bulimia were detected.
- Quality of life of the elderly people with chronic painPublication . Dixe, Maria dos Anjos; Querido, AnaAims: To determine the prevalence of Chronic Pain in Elderly People, to evaluate healthrelated quality-of-life of the elderly experiencing pain; and determine predictive factors of their quality-of-life.
- Alterações emocionais no pós-parto e amamentaçãoPublication . Ramalho, Sónia
- Atitudes dos educadores face mau trato infantil : construção e validação de uma escalaPublication . Catarino, Helena; Dixe, Maria dos Anjos; Vicente Castro, Florencio
- Dificuldades dos cuidadores de doentes dependentesPublication . Marques, Rita Margarida Dourado; Dixe, Maria dos AnjosIntrodução e objectivos: É bem conhecido que uma das causas das sucessivas recorrências dos doentes dependentes ao serviço de urgência, nomeadamente os idosos, se prende com dificuldades sentidas pelos cuidadores no domicílio pelo que este estudo teve como objectivos determinar a taxa de prevalência, os factores preditivos de readmissão dos doentes dependentes e conhecer quais são as dificuldades dos seus cuidadores e as respostas prestadas pelos serviços de saúde. Metodologia: Neste estudo correlacionado aplicamos uma entrevista a 107 doentes dependentes e seus cuidadores que recorreram a um Serviço de Urgência de um Hospital Central de Lisboa nos meses de Abril a Julho. A taxa de prevalência foi determinada através de uma entrevista telefónica um mês após a entrevista e alta do serviço de Urgencia. Resultados: Os resultados demonstraram uma taxa de readmissão de 28%. Informação sobre a Satisfação das Necessidades Humanas Básicas do doente, sintomas da doença, evolução e prognostico assim como a medicação e seus efeitos foram as necessidades mais referidas pelos cuidadores. Um menor nível de dependência e menor número de dias decorridos desde a última vinda do doente ao serviço de urgência foram determinadas como factores preditivos da readmissão. As caracteristicas sociodemograficas tanto do doente como do cuidador não constituem factores preditivos de readmissão.