145 research outputs found

    The ₉₅RGD₉₇ sequence on the A alpha chain of fibrinogen is essential for binding to its erythrocyte receptor

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    Background: Erythrocyte aggregation, a cardiovascular risk factor, is increased by high plasma fibrinogen levels. Here, the effect of different fibrinogen mutations on binding to its human erythrocyte receptor was assessed in order to identify the interaction sites. Methods: Three fibrinogen variants were tested, specifically mutated in their putative integrin recognition sites on the Aα chain (mutants D97E, D574E and D97E/D574E) and compared with wild-type fibrinogen. Results: Atomic force microscopy-based force spectroscopy measurements showed a significant decrease both on the fibrinogen–erythrocyte binding force and on its frequency for fibrinogen with the D97E mutation, indicating that the corresponding arginine–glycine–aspartate sequence (residues 95–97) is involved in this interaction, and supporting that the fibrinogen receptor on erythrocytes has a β3 subunit. Changes in the fibrin clot network structure obtained with the D97E mutant were observed by scanning electron microscopy. Conclusion: These findings may lead to innovative perspectives on the development of new therapeutic approaches to overcome the risks of fibrinogen-driven erythrocyte hyperaggregation

    Sensing adhesion forces between erythrocytes and γ’ fibrinogen, modulating fibrin clot architecture and function

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    Plasma fibrinogen includes an alternatively spliced γ-chain variant (γ’), which mainly exists as a heterodimer (γAγ’) and has been associated with thrombosis. We tested γAγ’ fibrinogen-red blood cells (RBCs) interaction using atomic force microscopy-based force spectroscopy, magnetic tweezers, fibrin clot permeability, scanning electron microscopy and laser scanning confocal microscopy. Data reveal higher work necessary for RBC-RBC detachment in the presence of γAγ’ rather than γAγA fibrinogen. γAγ’ fibrinogen–RBCs interaction is followed by changes in fibrin network structure, which forms an heterogeneous clot structure with areas of denser and highly branched fibrin fibers. The presence of RBCs also increased the stiffness of γAγ’ fibrin clots, which are less permeable and more resistant to lysis than γAγA clots. The modifications on clots promoted by RBCs-γAγ’ fibrinogen interaction could alter the risk of thrombotic disorders

    Composição corporal e percepção de autoimagem em universitárias

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    Introduction: Body image is the way we perceive the body. To recognize it is to clearly state its existence and, from this perception, to see the body's capacity to be changeable, that is, it can be changed at any moment. Objective: Classify the level of distortion of body self-image of university students of the physical education course of a public university of Pauí (UFPI) and verify its relation with anthropometric parameters, since it is believed that these students tend to present a greater concern with their appearance. Methodology: Study is descriptive and quantitative having a sample of 105 students, enrolled between the year of 2011 and 2015 and representing 75% of the total student population, were selected to participate of this descriptive-quantitative study. The self-image distortion was evaluated through the Body Shape Questionnaire (BSQ) and a body control scale was used for the analysis of body weight, composition and metabolism. Results: The students were 21.5±1.8 years old, 58.3±2.0kg weight and 160.6±2.1cm height. Regarding the anthropometric evaluation, students presented body mass index of 22.4±0.6; waist circumference of 70.6±0.8cm and waist/hip ratio of 0.73±0.01cm - values considered normal for adult women. The value obtained from the QSB, 84.2±9.6 points, indicates a slight distortion in the self-body perception. This distortion is present in 53% of the total participants. In conclusion these findings are worrisome because they are a group of future professionals that will work on and promote health and body practices.Introdução: A imagem corporal é a forma como percebemos o corpo. Reconhecê-la é afirmar com clareza sua existência e, a partir dessa percepção, ver a capacidade do corpo ser mutável, ou seja, ele pode a cada momento ser alterado. Objetivo: Classificar o nível de distorção da autoimagem corporal de universitárias do curso de Educação Física de uma universidade pública do Piauí e verificar a relação com os parâmetros antropométricos, pois se acredita que essas estudantes tendem a apresentar uma preocupação maior com a aparência. Metodologia: Estudo é de carácter descritivo e quantitativo, tendo uma amostra de 105 universitárias com ingresso entre 2011 a 2015, as quais representam 75% do total da população. Para avaliar a distorção da autoimagem foi utilizado o questionário Body Shape Questionnaire (BSQ), e para a análise de peso, composição e metabolismo corporal, uma balança de controle corporal (Omron, modelo HBF-514C). Resultados: As estudantes apresentaram idade de 21,5±1,8 anos, peso 58,3±2,0 kg, estatura 160,6±2,1cm, Ãndice de Massa Corporal 22,4±0,6kg/m2; Circunferência da Cintura 70,6±0,8cm e Relação da Cintura/Quadril 0,73±0,01cm, sendo todos esses valores normais para mulheres adultas. Em relação à autoimagem corporal foi encontrado o valor de 84,2±9,6 pontos, que indica uma leve distorção. Essa alteração esteve presente em 53% das participantes. Conclusão: Desta forma, esses achados revelam-se preocupantes pelo fato de se tratar de um grupo de futuros profissionais, multiplicadores de conceitos, da área de saúde e orientadores de práticas corporais

    The burden of mental disorders, substance use disorders and self-harm among young people in Europe, 1990–2019: Findings from the Global Burden of Disease Study 2019

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    BACKGROUND: Mental health is a public health issue for European young people, with great heterogeneity in resource allocation. Representative population-based studies are needed. The Global Burden of Disease (GBD) Study 2019 provides internationally comparable information on trends in the health status of populations and changes in the leading causes of disease burden over time. METHODS: Prevalence, incidence, Years Lived with Disability (YLDs) and Years of Life Lost (YLLs) from mental disorders (MDs), substance use disorders (SUDs) and self-harm were estimated for young people aged 10-24 years in 31 European countries. Rates per 100,000 population, percentage changes in 1990-2019, 95% Uncertainty Intervals (UIs), and correlations with Sociodemographic Index (SDI), were estimated. FINDINGS: In 2019, rates per 100,000 population were 16,983 (95% UI 12,823 – 21,630) for MDs, 3,891 (3,020 - 4,905) for SUDs, and 89·1 (63·8 - 123·1) for self-harm. In terms of disability, anxiety contributed to 647·3 (432–912·3) YLDs, while in terms of premature death, self-harm contributed to 319·6 (248·9–412·8) YLLs, per 100,000 population. Over the 30 years studied, YLDs increased in eating disorders (14·9%;9·4-20·1) and drug use disorders (16·9%;8·9-26·3), and decreased in idiopathic developmental intellectual disability (–29·1%;23·8-38·5). YLLs decreased in self-harm (–27·9%;38·3-18·7). Variations were found by sex, age-group and country. The burden of SUDs and self-harm was higher in countries with lower SDI, MDs were associated with SUDs. INTERPRETATION: Mental health conditions represent an important burden among young people living in Europe. National policies should strengthen mental health, with a specific focus on young people. FUNDING: The Bill and Melinda Gates Foundatio

    TLR9 activation dampens the early inflammatory response to paracoccidioides brasiliensis, Impacting host survival

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    Background: Paracoccidioides brasiliensis causes paracoccidioidomycosis, one of the most prevalent systemic mycosis in Latin America. Thus, understanding the characteristics of the protective immune response to P. brasiliensis is of interest, as it may reveal targets for disease control. The initiation of the immune response relies on the activation of pattern recognition receptors, among which are TLRs. Both TLR2 and TLR4 have been implicated in the recognition of P. brasiliensis and regulation of the immune response. However, the role of TLR9 during the infection by this fungus remains unclear.J.F. Menino was supported by a grant from Fundacao para a Ciencia e Tecnologia (FCT), Portugal (SFRH/BD/33446/2008). This work was supported by a grant from FCT (PTDC/BIA-MIC/108309/2008). M. Saraiva is a Ciencia 2007 fellow and M. Sturme is a Ciencia 2008 fellow. We would also like to thank FAPESP (Fundacao para Amparo a Pesquisa do Estado de Sao Paulo) and CNPq (Conselho Nacional de Desenvolvimento Cientifico e Tecnologico) for financial support. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript

    Which Factors Determine Spatial Segregation in the South American Opossums (Didelphis aurita and D. albiventris)? An Ecological Niche Modelling and Geometric Morphometrics Approach

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    Didelphis albiventris and D. aurita are Neotropical marsupials that share a unique evolutionary history and both are largely distributed throughout South America, being primarily allopatric throughout their ranges. In the Araucaria moist forest of Southern Brazil these species are sympatric and they might potentially compete having similar ecology. For this reason, they are ideal biological models to address questions about ecological character displacement and how closely related species might share their geographic space. Little is known about how two morphologically similar species of marsupials may affect each other through competition, if by competitive exclusion and competitive release. We combined ecological niche modeling and geometric morphometrics to explore the possible effects of competition on their distributional ranges and skull morphology. Ecological niche modeling was used to predict their potential distribution and this method enabled us to identify a case of biotic exclusion where the habit generalist D. albiventris is excluded by the presence of the specialist D. aurita. The morphometric analyses show that a degree of shape discrimination occurs between the species, strengthened by allometric differences, which possibly allowed them to occupy marginally different feeding niches supplemented by behavioral shift in contact areas. Overlap in skull morphology is shown between sympatric and allopatric specimens and a significant, but weak, shift in shape occurs only in D. aurita in sympatric areas. This could be a residual evidence of a higher past competition between both species, when contact zones were possibly larger than today. Therefore, the specialist D. aurita acts a biotic barrier to D. albiventris when niche diversity is not available for coexistence. On the other hand, when there is niche diversification (e.g. habitat mosaic), both species are capable to coexist with a minimal competitive effect on the morphology of D. aurita

    Comprehensive genetic assessment of a functional TLR9 promoter polymorphism: no replicable association with asthma or asthma-related phenotypes

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    <p>Abstract</p> <p>Background</p> <p>Prior studies suggest a role for a variant (rs5743836) in the promoter of toll-like receptor 9 (TLR9) in asthma and other inflammatory diseases. We performed detailed genetic association studies of the functional variant rs5743836 with asthma susceptibility and asthma-related phenotypes in three independent cohorts.</p> <p>Methods</p> <p>rs5743836 was genotyped in two family-based cohorts of children with asthma and a case-control study of adult asthmatics. Association analyses were performed using chi square, family-based and population-based testing. A luciferase assay was performed to investigate whether rs5743836 genotype influences TLR9 promoter activity.</p> <p>Results</p> <p>Contrary to prior reports, rs5743836 was not associated with asthma in any of the three cohorts. Marginally significant associations were found with FEV<sub>1 </sub>and FVC (p = 0.003 and p = 0.008, respectively) in one of the family-based cohorts, but these associations were not significant after correcting for multiple comparisons. Higher promoter activity of the CC genotype was demonstrated by luciferase assay, confirming the functional importance of this variant.</p> <p>Conclusion</p> <p>Although rs5743836 confers regulatory effects on TLR9 transcription, this variant does not appear to be an important asthma-susceptibility locus.</p
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