Antimicrobial properties of membrane-active dodecapeptides derived from MSI-78

Antimicrobial peptides (AMPs) are a class of broad-spectrum antibiotics known by their ability to disrupt bacterial membranes and their low tendency to induce bacterial resistance, arising as excellent candidates to fight bacterial infections. In this study we aimed at designing short 12-mer AMPs, derived from a highly effective and broad spectrum synthetic AMP, MSI-78 (22 residues), by truncating this peptide at the N- and/or C-termini while spanning its entire sequence with 1 amino add (aa) shifts. These designed peptides were evaluated regarding antimicrobial activity against selected gram-positive Staphylococcus strains and the gram-negative Pseudomonas aeruginosa (P. aeruginosa). The short 12-mer peptide CEM1 (GIGMFLKKAKICF) was identified as an excellent candidate to fight P. aeruginosa infections as it displays antimicrobial activity against this strain and selectivity, with negligible toxicity to mammalian cells even at high concentrations. However, in general most of the short 12-mer peptides tested showed a reduction in antimicrobial activity, an effect that was more pronounced for gram-positive Staphylococcus strains. Interestingly, CEM1 and a highly similar peptide differing by only one aa-shift (CEM2: IGKFLKKAKICFG), showed a remarkably contrasting AMP activity. These two peptides were chosen for a more detailed study regarding their mechanism of action, using several biophysical assays and simple membrane models that mimic the mammalian and bacterial lipid composition. We confirmed the correlation between peptide helicity and antimicrobial activity and propose a mechanism of action based on the disruption of the bacterial membrane permeability barrier

A 17-mer Membrane-Active MSI-78 Derivative with Improved Selectivity toward Bacterial Cells

Antimicrobial peptides are widely recognized as an excellent alternative to conventional antibiotics. MSI-78, a highly effective and broad spectrum AMP, is one of the most promising AMPs for clinical application. In this study, we have designed shorter derivatives of MSI-78 with the aim of improving selectivity while maintaining antimicrobial activity. Shorter 17-mer derivatives were created by truncating MSI-78 at the N- and/or C-termini, while spanning MSI-78 sequence. Despite the truncations made, we found a 17-mer peptide, MSI-78(4-20) (KFLKKAKKFGKAFVKIL), which was demonstrated to be as effective as MSI-78 against the Gram-positive Staphylococcus strains tested and the Gram-negative Pseudomonas aeruginosa. This shorter derivative is more selective toward bacterial cells as it was less toxic to erythrocytes than MSI-78, representing an improved version of the lead peptide. Biophysical studies support a mechanism of action for MSI-78(4-20) based on the disruption of the bacterial membrane permeability barrier, which in turn leads to loss of membrane integrity and ultimately to cell death. These features point to a mechanism of action similar to the one described for the lead peptide MSI-78

Características produtivas e reprodutivas de vacas primíparas f1 holandês x zebu de diferentes bases maternas / Productive and reproductive characteristics of primary parts f1 dutch x zebu of different maternal bases

A utilização de animais mestiços vem crescendo cada vez mais, visto que o clima tropical brasileiro inviabiliza o uso de animais puros para produção de leite. Porém as possibilidades de cruzamentos com touro da raça holandês com diversas bases maternas zebu geram animais com características diferentes, as quais precisam ser estudadas para melhor adequar o sistema. O objetivo do presente trabalho foi avaliar as características de produção e reprodução de quatro grupos de bases maternas distintas. Para tal, foram utilizados quatro grupos maternos para as avaliações, sendo eles, Gir, Nelogir, Guzonel e Nelore as quais foram analisadas por análise de variância e com efeitos significativos dos fatores comparados pelo teste Scott-Knott a 5% de significância. Foram testadas correlações entre variáveis dependentes. Para o processamento das análises utilizou-se os procedimentos do Software Sistema de Análises Estatísticas (SAEG), versão 9.1. Dentre as características produtivas avaliadas somente media diária/intervalo de partos não sofreu interferência (P<0,05) do grupo genético, das características reprodutivas avaliadas período de serviço e intervalo de parto, sofreu influência (P<0,05) da base materna, sendo que animais de base nelore obtiveram menores valores de 56,0 ±21,7 dias, 343,0 ±21,7 dias, respectivamente. 

Detection and differentiation of dengue virus serotypes by one-step multiplex reverse transcription PCR assays / Detecção e diferenciação de sorotipos do vírus da dengue por ensaios de PCR com transcrição reversa multiplexada em uma etapa

Background: Dengue infections are a severe public health problem in Brazil. The Ministry of Health recommends an immunosorbent assay (ELISA) for the capture of IgM (MAC-ELISA) to diagnose dengue. However, it detects antibodies that cross-react with other flaviviruses and requires confirmation in reference laboratories. Methods: One-step multiplex RT-PCR assay was used to amplify RNA of 197 serum from patients with clinical suspicion of dengue infection. The samples had been screened with the IgM ELISA kit in the Central Public Health Laboratory of the State of Maranhão. Results: Of the 197 samples evaluated by IgM ELISA, 135 were positive; of these, 96 (71.1%) were from patients in the acute phase of the infection. The one-step multiplex RT-PCR detected viral RNA in 88 (91.7%) of this serum. Among the 62-negative serum by ELISA, 29 samples (46.8%) were amplified using the molecular method. Conclusions: One-step multiplex RT-PCR was sensitive in the detection of viral particles from the first day until the sixth day after the onset of the feverish period. Moreover, it was specific and 100% reproducible. Based on these results, we recommend the use of this molecular assay to diagnose and differentiate the DENV serotypes in the acute phase of the disease.Background: Dengue infections are a severe public health problem in Brazil. The Ministry of Health recommends an immunosorbent assay (ELISA) for the capture of IgM (MAC-ELISA) to diagnose dengue. However, it detects antibodies that cross-react with other flaviviruses and requires confirmation in reference laboratories. Methods: One-step multiplex RT-PCR assay was used to amplify RNA of 197 serum from patients with clinical suspicion of dengue infection. The samples had been screened with the IgM ELISA kit in the Central Public Health Laboratory of the State of Maranhão. Results: Of the 197 samples evaluated by IgM ELISA, 135 were positive; of these, 96 (71.1%) were from patients in the acute phase of the infection. The one-step multiplex RT-PCR detected viral RNA in 88 (91.7%) of this serum. Among the 62-negative serum by ELISA, 29 samples (46.8%) were amplified using the molecular method. Conclusions: One-step multiplex RT-PCR was sensitive in the detection of viral particles from the first day until the sixth day after the onset of the feverish period. Moreover, it was specific and 100% reproducible. Based on these results, we recommend the use of this molecular assay to diagnose and differentiate the DENV serotypes in the acute phase of the disease

Highlights of the Brazilian Thoracic Association guidelines for interstitial lung diseases

Interstitial lung diseases (ILDs) are heterogeneous disorders, involving a large number of conditions, the approach to which continues to pose an enormous challenge for pulmonologists. The 2012 Brazilian Thoracic Association ILD Guidelines were established in order to provide Brazilian pulmonologists with an instrument that can facilitate the management of patients with ILDs, standardizing the criteria used for the diagnosis of different conditions and offering guidance on the best treatment in various situations. The objective of this article was to briefly describe the highlights of those guidelines.As doenças pulmonares intersticiais (DPIs) são afecções heterogêneas, envolvendo um elevado número de condições, cuja abordagem ainda é um grande desafio para o pneumologista. As Diretrizes de DPIs da Sociedade Brasileira de Pneumologia e Tisiologia, publicadas em 2012, foram estabelecidas com o intuito de fornecer aos pneumologistas brasileiros um instrumento que possa facilitar a abordagem dos pacientes com DPIs, padronizando-se os critérios utilizados para a definição diagnóstica das diferentes condições, além de orientar sobre o melhor tratamento nas diferentes situações. Esse artigo teve como objetivo descrever resumidamente os principais destaques dessas diretrizes.Universidade de São Paulo Faculdade de Medicina Hospital das ClínicasUniversidade Federal de São Paulo (UNIFESP) Escola Paulista de Medicina Curso de Pós-Graduação de Doenças Pulmonares IntersticiaisUniversidade Federal de Ciências da Saúde de Porto AlegreSanta Casa de Porto Alegre Ambulatório de Doenças IntersticiaisSES Hospital Regional da Asa Norte Serviço de Doenças TorácicasFundação Jorge Duprat Figueiredo de Segurança e Medicina do Trabalho Serviço de MedicinaUniversidade Estadual de Campinas Faculdade de Ciências Médicas Departamento de Clínica MédicaUniversidade Federal do Estado do Rio de JaneiroUniversidade Federal de São Paulo (UNIFESP) Escola Paulista de Medicina Departamento de PatologiaHospital do Servidor Público Estadual de São Paulo Serviço de Anatomia PatológicaUniversidade Federal de São Paulo (UNIFESP) Escola Paulista de MedicinaUniversidade de São Paulo Faculdade de Medicina de Ribeirão Preto Divisão de PneumologiaUniversidade Federal de Santa Catarina Departamento de Clínica MédicaUniversidade Federal de Santa Catarina Hospital UniversitárioHospital de Messejana Ambulatório de Doenças IntersticiaisHospital do Servidor Público Estadual de São Paulo Ambulatório de Doenças IntersticiaisUniversidade de São Paulo Faculdade de Medicina Instituto do CoraçãoUniversidade Federal FluminenseUniversidade de São Paulo Faculdade de MedicinaHospital Sírio Libanês Núcleo Avançado de TóraxUniversidade Federal da BahiaHospital do Servidor Público Estadual de São PauloHospital do Câncer Antônio Cândido CamargoUNIFESP, EPM, Curso de Pós-Graduação de Doenças Pulmonares IntersticiaisUNIFESP, EPM, Depto. de PatologiaUNIFESP, EPMSciEL

Highlights of the Brazilian Thoracic Association guidelines for interstitial lung diseases

Interstitial lung diseases (ILDs) are heterogeneous disorders, involving a large number of conditions, the approach to which continues to pose an enormous challenge for pulmonologists. The 2012 Brazilian Thoracic Association ILD Guidelines were established in order to provide Brazilian pulmonologists with an instrument that can facilitate the management of patients with ILDs, standardizing the criteria used for the diagnosis of different conditions and offering guidance on the best treatment in various situations. The objective of this article was to briefly describe the highlights of those guidelines.As doenças pulmonares intersticiais (DPIs) são afecções heterogêneas, envolvendo um elevado número de condições, cuja abordagem ainda é um grande desafio para o pneumologista. As Diretrizes de DPIs da Sociedade Brasileira de Pneumologia e Tisiologia, publicadas em 2012, foram estabelecidas com o intuito de fornecer aos pneumologistas brasileiros um instrumento que possa facilitar a abordagem dos pacientes com DPIs, padronizando-se os critérios utilizados para a definição diagnóstica das diferentes condições, além de orientar sobre o melhor tratamento nas diferentes situações. Esse artigo teve como objetivo descrever resumidamente os principais destaques dessas diretrizes.28229

A RELAÇÃO ENTRE O USO EXCESSIVO DE REDES SOCIAIS E A SAÚDE MENTAL DOS JOVENS

This study explores the relationship between excessive social media use and mental health in young people. The research reveals that intense use of these platforms is associated with increased symptoms of depression and anxiety, reflecting the growing concern about the psychological impact of social media. Evidence analysis points out that frequent use contributes to issues such as low self-esteem and stress. The literature review indicates that both young adults and adolescents are negatively affected, showing a significant increase in emotional disorders due to prolonged exposure to social media. The main objective of the work is to better understand how excessive social media use influences mental health and to suggest strategies to mitigate these adverse impacts.Este estudo explora a relação entre o uso excessivo de redes sociais e a saúde mental dos jovens. A pesquisa revela que o uso intenso dessas plataformas está associado a um aumento dos sintomas de depressão e ansiedade, refletindo a crescente preocupação com o impacto psicológico das redes sociais. A análise das evidências aponta que o uso frequente dessas redes contribui para problemas como baixa autoestima e estresse. A revisão bibliográfica indica que tanto jovens adultos quanto adolescentes são afetados negativamente, apresentando um aumento significativo nos transtornos emocionais devido à exposição prolongada a redes sociais. O objetivo principal do trabalho é compreender melhor como o uso excessivo de redes sociais influencia a saúde mental e sugerir estratégias para mitigar esses impactos adversos