79 research outputs found

    Adaptação e evidências de validade do Traumatic Grief Inventory para o Brasil

    Get PDF
    The aim of the this study was to verify the evidence of validity of the reduced version adapted for Brazilian Portuguese of the Traumatic Grief Inventory, through confirmatory factor analysis and relationship with external variables, in addition to assessing the reliability and presence of invariance. The first step consisted of the adaptation and evaluation by expert judges of the translated version. After the evaluation, the pilot version was answered by five participants of the target population, for semantic and content evaluation, being named, in Brazil, as the Inventário de Luto Traumático (ILT-BR). Then, 211 Brazilians, who went through a grieving process, answered the following instruments: Sociodemographic Questionnaire, Mental Health Self-Perception Questionnaire, and ILT-BR. The ILT-BR presented good fit indexes and reliability, positively correlated with stress, fear, and obsessive thoughts, with no invariance found. From these results, we concluded that the ILT-BR is suitable for use in Brazil.El objetivo de este estudio fue verificar la evidencia de validez de la versión reducida adaptada al portugués brasileño del Traumatic Grief Inventory (Inventario de Duelo Traumático), mediante un análisis factorial confirmatorio y la relación con variables externas, además de evaluar la precisión y presencia de invarianza. El primer paso fue la adaptación y evaluación por jueces expertos de la versión traducida. Después de la evaluación, se aplicó la versión piloto a cinco participantes de la población objetivo para la evaluación semántica y de contenido, denominándose Inventario de Luto Traumático (ILT-BR). Luego, 211 brasileños, que pasaron por un proceso de duelo, respondieron los siguientes instrumentos: Cuestionario Sociodemográfico, Cuestionario de Autopercepción de Salud Mental e ILT-BR. El ILT-BR mostró buenos índices de ajuste y precisión, correlacionándose positivamente con el estrés, el miedo y los pensamientos obsesivos, sin encontrar variación entre grupos. A partir de estos resultados, se concluye que el ILT-BR posee propiedades psicométricas adecuadas para su uso en Brasil.O objetivo do presente estudo foi verificar as evidências de validade da versão reduzida adaptada para o português do Brasil do Traumatic Grief Inventory, por meio de uma análise fatorial confirmatória e relação com variáveis externas, além de aferir a precisão e presença de invariância. A primeira etapa consistiu na adaptação e avaliação por juízes especialistas da versão traduzida. Após a avaliação, a versão piloto foi aplicada em cinco participantes da população-alvo para avaliação semântica e de conteúdo, sendo nomeado de Inventário de Luto Traumático (ILT-BR). Em seguida, 211 brasileiros, que passaram por um processo de luto, responderam aos seguintes instrumentos: Questionário Sociodemográfico, Questionário de Autopercepção de Saúde Mental e ILT-BR. O ILT-BR apresentou bons índices de ajuste e precisão, se correlacionando positivamente com estresse, medo e pensamentos obsessivos, sem variação entre grupos. A partir destes resultados, conclui-se que há evidências de que o ILT-BR apresenta boas propriedades psicométricas

    Peptide:lipid ratio and membrane surface charge determine the mechanism of action of the antimicrobial peptide BP100. Conformational and functional studies

    Get PDF
    The cecropin-melittin hybrid antimicrobial peptide BP100 (H-KKLFKKILKYL-NH2) is selective for Gram-negative bacteria, negatively charged membranes, and weakly hemolytic. We studied BP100 conformational and functional properties upon interaction with large unilamellar vesicles, LUVs, and giant unilamellar vesicles, GUVs, containing variable proportions of phosphatidylcholine (PC) and negatively charged phosphatidylglycerol (PG). CD and NMR spectra showed that upon binding to PG-containing LUVs BP100 acquires a-helical conformation, the helix spanning residues 3-11. Theoretical analyses indicated that the helix is amphipathic and surface-seeking. CD and dynamic light scattering data evinced peptide and/or vesicle aggregation, modulated by peptide: lipid ratio and PG content. BP100 decreased the absolute value of the zeta potential () of LUVs with low PG contents; for higher PG, binding was analyzed as an ion-exchange process. At high salt, BP100-induced LUVS leakage requires higher peptide concentration, indicating that both electrostatic and hydrophobic interactions contribute to peptide binding. While a gradual release took place at low peptide:lipid ratios, instantaneous loss occurred at high ratios, suggesting vesicle disruption. Optical microscopy of GUVs confirmed BP100-promoted disruption of negatively charged membranes. the mechanism of action of BP100 is determined by both peptide:lipid ratio and negatively charged lipid content While gradual release results from membrane perturbation by a small number of peptide molecules giving rise to changes in acyl chain packing, lipid clustering (leading to membrane defects), and/or membrane thinning, membrane disruption results from a sequence of events large-scale peptide and lipid clustering, giving rise to peptide-lipid patches that eventually would leave the membrane in a carpet-like mechanism. (C) 2014 Elsevier B.V. All rights reserved.Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Institut Nacional de Ciencia e Tecnologia de fluidos complexos (INCTFCx)Nude de Apoio Pesquisa de Fluidos Complexos (NAPFCx)Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)Univ São Paulo, Inst Chem, Dept Biochem, BR-05513970 São Paulo, BrazilUniversidade Federal de São Paulo, Dept Biophys, BR-04044020 São Paulo, BrazilUniv Fed Rio de Janeiro, Inst Med Biochem, Nucl Magnet Resonance Natl Ctr, Rio de Janeiro, BrazilEmbrapa Recursos Genet & Biotecnol, BR-70770917 Brasilia, DF, BrazilUniversidade Federal de São Paulo, Dept Biophys, BR-04044020 São Paulo, BrazilFAPESP: 2007/50970-5FAPESP: 2013/08166-5Web of Scienc

    Roles for Treg expansion and HMGB1 signaling through the TLR1-2-6 axis in determining the magnitude of the antigen-specific immune response to MVA85A

    Get PDF
    © 2013 Matsumiya et al. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are creditedA better understanding of the relationships between vaccine, immunogenicity and protection from disease would greatly facilitate vaccine development. Modified vaccinia virus Ankara expressing antigen 85A (MVA85A) is a novel tuberculosis vaccine candidate designed to enhance responses induced by BCG. Antigen-specific interferon-γ (IFN-γ) production is greatly enhanced by MVA85A, however the variability between healthy individuals is extensive. In this study we have sought to characterize the early changes in gene expression in humans following vaccination with MVA85A and relate these to long-term immunogenicity. Two days post-vaccination, MVA85A induces a strong interferon and inflammatory response. Separating volunteers into high and low responders on the basis of T cell responses to 85A peptides measured during the trial, an expansion of circulating CD4+ CD25+ Foxp3+ cells is seen in low but not high responders. Additionally, high levels of Toll-like Receptor (TLR) 1 on day of vaccination are associated with an increased response to antigen 85A. In a classification model, combined expression levels of TLR1, TICAM2 and CD14 on day of vaccination and CTLA4 and IL2Rα two days post-vaccination can classify high and low responders with over 80% accuracy. Furthermore, administering MVA85A in mice with anti-TLR2 antibodies may abrogate high responses, and neutralising antibodies to TLRs 1, 2 or 6 or HMGB1 decrease CXCL2 production during in vitro stimulation with MVA85A. HMGB1 is released into the supernatant following atimulation with MVA85A and we propose this signal may be the trigger activating the TLR pathway. This study suggests an important role for an endogenous ligand in innate sensing of MVA and demonstrates the importance of pattern recognition receptors and regulatory T cell responses in determining the magnitude of the antigen specific immune response to vaccination with MVA85A in humans.This work was funded by the Wellcome Trust. MM has a Wellcome Trust PhD studentship and HM is a Wellcome Trust Senior Fello
    corecore