38 research outputs found

    Efeito protetor do pré-tratamento com ácido ascóbico em modelo experimental de isquemia-reperfusão intestinal: um estudo histomorfométrico

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    BACKGROUND: Ascorbic acid has shown promise in attenuation of intestinal ischemia-reperfusion (I/R) injury. The aim of this study was to determine the protective effects of ascorbic acid on intestinal morphology during IR injury in rats. MATERIALS AND METHODS: We examined morphological changes in the small intestine of Wistar rats after (i) 40 minutes of ischemia (I), (ii) ischemia followed by 30 min of reperfusion (IR), (iii) ischemia with ascorbic acid (IA), (iv) ischemia followed by reperfusion and ascorbic acid (IRA) and (v) in a sham group (S). We used morphometry to evaluate the amount of villous architecture, crypts, necrosis, hemorrhagic infarcts and inflammatory cells at the mesenteric and antimesenteric borders of the small intestine. RESULTS: Ascorbic acid caused a significant reduction of antimesenteric villous hemorrhagic infarction (pINTRODUÇÃO: O ácido ascórbico tem se mostrado como um agente promissor na atenuação da lesão causada pela isquemia/reperfusão (IR). O objetivo deste estudo foi determinar os efeitos protetores do ácido ascórbico na morfologia intestinal durante a IR em ratos. MATERIAL E MÉTODOS: Examinamos alterações morfológicas no intestino delgado de ratos do tipo Wistar. Após 40 minutos de isquemia (I), isquemia seguida de reperfusão (IR), isquemia com tratamento com ácido ascórbico (IA), isquemia seguida por 30 minutos de reperfusão e tratamento com ácido ascórbico (IRA) e do grupo sham (S). Utilizamos a morfometria para avaliar quantitativamente a arquitetura dos vilos da mucosa intestinal, criptas intestinais, necrose, hemorragia, células inflamatórias nas bordas mesentéricas e antimesentéricas do intestino delgado. RESULTADOS: O ácido ascórbico causou uma redução significativa (

    Abordagens Atuais no Tratamento da Diabetes Tipo 2: Uma revisão das terapias farmacológicas e não farmacológicas mais recentes para o controle da DM2.

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    This review article delves into current approaches in the treatment of type 2 diabetes (T2DM), a chronic metabolic condition that poses a significant challenge to global health. The aim is to assess the efficacy of the latest pharmacological and non-pharmacological therapies in T2DM management, considering both glycemic control and cardiovascular outcomes. In terms of pharmacological therapies, metformin remains an effective choice as initial therapy due to its proven ability to lower hemoglobin A1c (HbA1c) levels. However, subsequent pharmacological therapies should be selected based on individual patient characteristics. Sodium-glucose cotransporter 2 (SGLT2) inhibitors and glucagon-like peptide-1 (GLP-1) receptor agonists have emerged as versatile options that not only reduce HbA1c but also improve cardiovascular outcomes. On the other hand, non-pharmacological therapies such as diet and exercise continue to be fundamental pillars in T2DM management. Healthy diets, such as the Mediterranean diet, have shown benefits in reducing HbA1c and promoting cardiovascular health. Regular exercise improves insulin sensitivity and contributes to weight loss. Additionally, bariatric surgery is an effective option in selected cases but requires careful evaluation due to associated risks. In summary, the management of T2DM necessitates an integrated approach that takes into account both pharmacological and non-pharmacological therapies, as well as individual patient characteristics. Understanding these therapeutic options is crucial for achieving adequate glycemic control and improving the quality of life of T2DM patients.  Este artigo de revisão aborda as abordagens atuais no tratamento da diabetes tipo 2 (DM2), uma condição metabólica crônica que representa um desafio significativo para a saúde global. O objetivo é analisar a eficácia das terapias farmacológicas e não farmacológicas mais recentes no controle da DM2, considerando tanto o controle glicêmico quanto os desfechos cardiovasculares. No que diz respeito às terapias farmacológicas, a metformina permanece como uma escolha eficaz como terapia inicial, devido à sua capacidade comprovada de reduzir os níveis de hemoglobina A1c (HbA1c). No entanto, terapias farmacológicas subsequentes devem ser escolhidas com base nas características individuais do paciente. Inibidores do cotransportador de sódio-glicose 2 (SGLT2) e agonistas do receptor de peptídeo semelhante ao glucagon 1 (GLP-1) emergiram como opções versáteis que não apenas reduzem HbA1c, mas também melhora os desfechos cardiovasculares. Por outro lado, as terapias não farmacológicas, como dieta e exercício, continuam sendo pilares fundamentais no manejo da DM2. Dietas saudáveis, como a mediterrânea, têm demonstrado benefícios na redução de HbA1c e na promoção da saúde cardiovascular. O exercício regular melhora a sensibilidade à insulina e contribui para a perda de peso. Além disso, a cirurgia bariátrica é uma opção eficaz em casos selecionados, mas requer avaliação cuidadosa devido aos riscos envolvidos. Em resumo, a gestão da DM2 exige uma abordagem integrada que leve em consideração as terapias farmacológicas e não farmacológicas disponíveis, bem como as características individuais do paciente. A compreensão dessas opções terapêuticas é crucial para alcançar o controle glicêmico adequado e melhorar a qualidade de vida dos pacientes com DM2

    The cyanobacterial saxitoxin exacerbates neural cell death and brain malformations induced by zika virus

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    The northeast (NE) region of Brazil commonly goes through drought periods, which favor cyanobacterial blooms, capable of producing neurotoxins with implications for human and animal health. The most severe dry spell in the history of Brazil occurred between 2012 and 2016. Coincidently, the highest incidence of microcephaly associated with the Zika virus (ZIKV) outbreak took place in the NE region of Brazil during the same years. In this work, we tested the hypothesis that saxitoxin (STX), a neurotoxin produced in South America by the freshwater cyanobacteria Raphidiopsis raciborskii, could have contributed to the most severe Congenital Zika Syndrome (CZS) profile described worldwide. Quality surveillance showed higher cyanobacteria amounts and STX occurrence in human drinking water sup-plies of NE compared to other regions of Brazil. Experimentally, we described that STX dou-bled the quantity of ZIKV-induced neural cell death in progenitor areas of human brain organoids, while the chronic ingestion of water contaminated with STX before and during gestation caused brain abnormalities in offspring of ZIKV-infected immunocompetent C57BL/6J mice. Our data indicate that saxitoxin-producing cyanobacteria is overspread in water reservoirs of the NE and might have acted as a co-insult to ZIKV infection in Brazil. These results raise a public health concern regarding the consequences of arbovirus outbreaks happening in areas with droughts and/or frequent freshwater cyanobacterial blooms.Fil: Pedrosa, Carolina da S. G.. D’Or Institute for Research and Education; BrasilFil: Souza, Leticia R. Q.. D’Or Institute for Research and Education; BrasilFil: Gomes, Tiago A.. Universidade Federal do Rio de Janeiro; Brasil. Instituto Oswaldo Cruz; BrasilFil: de Lima, Caroline V. F.. D’Or Institute for Research and Education; BrasilFil: Ledur, Pitia F.. D’Or Institute for Research and Education; BrasilFil: Karmirian, Karina. D’Or Institute for Research and Education; Brasil. Universidade Federal do Rio de Janeiro; BrasilFil: Barbeito Andrés, Jimena. Universidade Federal do Rio de Janeiro; Brasil. Universidad Nacional Arturo Jauretche. Unidad Ejecutora de Estudios en Neurociencias y Sistemas Complejos. Provincia de Buenos Aires. Ministerio de Salud. Hospital Alta Complejidad en Red El Cruce Dr. Néstor Carlos Kirchner Samic. Unidad Ejecutora de Estudios en Neurociencias y Sistemas Complejos. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Unidad Ejecutora de Estudios en Neurociencias y Sistemas Complejos; ArgentinaFil: Costa, Marcelo do N.. Universidade Federal do Rio de Janeiro; BrasilFil: Higa, Luiza M.. Universidade Federal do Rio de Janeiro; BrasilFil: Rossi, Átila D.. Universidade Federal do Rio de Janeiro; BrasilFil: Bellio, Maria. Universidade Federal do Rio de Janeiro; BrasilFil: Tanuri, Amilcar. Universidade Federal do Rio de Janeiro; BrasilFil: Prata Barbosa, Arnaldo. D’Or Institute for Research and Education; BrasilFil: Tovar Moll, Fernanda. D’Or Institute for Research and Education; Brasil. Universidade Federal do Rio de Janeiro; BrasilFil: Garcez, Patricia P.. Universidade Federal do Rio de Janeiro; BrasilFil: Lara, Flavio A.. Instituto Oswaldo Cruz; BrasilFil: Molica, Renato J. R.. Universidad Federal Rural Pernambuco; BrasilFil: Rehen, Stevens K.. D’Or Institute for Research and Education; Brasil. Universidade Federal do Rio de Janeiro; Brasi

    Congenital Zika syndrome is associated with maternal protein malnutrition

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    Zika virus (ZIKV) infection during pregnancy is associated with a spectrum of developmental impairments known as congenital Zika syndrome (CZS). The prevalence of this syndrome varies across ZIKV endemic regions, suggesting that its occurrence could depend on cofactors. Here, we evaluate the relevance of protein malnutrition for the emergence of CZS. Epidemiological data from the ZIKV outbreak in the Americas suggest a relationship between undernutrition and cases of microcephaly. To experimentally examine this relationship, we use immunocompetent pregnant mice, which were subjected to protein malnutrition and infected with a Brazilian ZIKV strain. We found that the combination of protein restriction and ZIKV infection leads to severe alterations of placental structure and embryonic body growth, with offspring displaying a reduction in neurogenesis and postnatal brain size. RNA-seq analysis reveals gene expression deregulation required for brain development in infected low-protein progeny. These results suggest that maternal protein malnutrition increases susceptibility to CZS.Fil: Barbeito Andrés, Jimena. Universidade Federal do Rio de Janeiro; Brasil. Universidad Nacional Arturo Jauretche. Unidad Ejecutora de Estudios en Neurociencias y Sistemas Complejos. Provincia de Buenos Aires. Ministerio de Salud. Hospital Alta Complejidad en Red El Cruce Dr. Néstor Carlos Kirchner Samic. Unidad Ejecutora de Estudios en Neurociencias y Sistemas Complejos. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Unidad Ejecutora de Estudios en Neurociencias y Sistemas Complejos; ArgentinaFil: Pezzuto, Paula. Universidade Federal do Rio de Janeiro; BrasilFil: Higa, Luiza. Universidade Federal do Rio de Janeiro; BrasilFil: Dias, André Alves. Universidade Federal do Rio de Janeiro; BrasilFil: Vasconcelos, Janaina. Universidade Federal do Pará; BrasilFil: Santos, T. M. P.. Universidade Federal do Rio de Janeiro; BrasilFil: Ferreira, Jéssica. Universidade Federal do Rio de Janeiro; BrasilFil: Ferreira, R. O.. Universidade Federal do Rio de Janeiro; BrasilFil: Dutra, F. F.. Universidade Federal do Rio de Janeiro; BrasilFil: Rossi, A. D.. Universidade Federal do Rio de Janeiro; BrasilFil: Barbosa, R. V.. Universidade Federal Do Rio de Janeiro. Centro Nacional de Biologia Estrutural E Bioimagem.; BrasilFil: Amorim, C. K. N.. Evandro Chagas Institute; BrasilFil: de Souza, M. P. C.. Evandro Chagas Institute; BrasilFil: Chimelli, L.. Instituto Estadual do Cérebro Paulo Niemeyer ; BrasilFil: Aguiar, R. S.. Universidade Federal do Rio de Janeiro; BrasilFil: Gonzalez, Paula Natalia. Universidad Nacional Arturo Jauretche. Unidad Ejecutora de Estudios en Neurociencias y Sistemas Complejos. Provincia de Buenos Aires. Ministerio de Salud. Hospital Alta Complejidad en Red El Cruce Dr. Néstor Carlos Kirchner Samic. Unidad Ejecutora de Estudios en Neurociencias y Sistemas Complejos. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Unidad Ejecutora de Estudios en Neurociencias y Sistemas Complejos; ArgentinaFil: Lara, F. A.. Oswaldo Cruz Institute; BrasilFil: Castro, M.C.. Harvard University. Harvard School of Public Health; Estados UnidosFil: Molnár, Z.. University of Oxford; Reino UnidoFil: Lopes, R. T.. Universidade Federal do Rio de Janeiro; BrasilFil: Bozza, M. T.. Universidade Federal do Rio de Janeiro; BrasilFil: Vianez, J. L. S. G.. Evandro Chagas Institute; BrasilFil: Barbeito, Claudio Gustavo. Universidad Nacional de La Plata. Facultad de Ciencias Veterinarias; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata; ArgentinaFil: Cuervo, P.. Oswaldo Cruz Institute; BrasilFil: Bellio, M.. Universidade Federal do Rio de Janeiro; BrasilFil: Tanuri, A.. Universidade Federal do Rio de Janeiro; BrasilFil: Garcez, P. P.. Universidade Federal do Rio de Janeiro; Brasi

    Protective effects of ascorbic acid pretreatment in a rat model of intestinal ischemia-reperfusion injury: a histomorphometric study Efeito protetor do pré-tratamento com ácido ascóbico em modelo experimental de isquemia-reperfusão intestinal: um estudo histomorfométrico

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    BACKGROUND: Ascorbic acid has shown promise in attenuation of intestinal ischemia-reperfusion (I/R) injury. The aim of this study was to determine the protective effects of ascorbic acid on intestinal morphology during IR injury in rats. MATERIALS AND METHODS: We examined morphological changes in the small intestine of Wistar rats after (i) 40 minutes of ischemia (I), (ii) ischemia followed by 30 min of reperfusion (IR), (iii) ischemia with ascorbic acid (IA), (iv) ischemia followed by reperfusion and ascorbic acid (IRA) and (v) in a sham group (S). We used morphometry to evaluate the amount of villous architecture, crypts, necrosis, hemorrhagic infarcts and inflammatory cells at the mesenteric and antimesenteric borders of the small intestine. RESULTS: Ascorbic acid caused a significant reduction of antimesenteric villous hemorrhagic infarction (p<0.05) of the small intestine after ischemia followed by reperfusion as well as villous necrosis reduction at both borders after ischemia (p<0.05). The lesions found in the small intestine were more prominent along the antimesenteric margin. CONCLUSIONS: Ascorbic acid pretreatment has a protective effect against the intestinal morphological lesions induced by ischemia-reperfusion injury in rats.<br>INTRODUÇÃO: O ácido ascórbico tem se mostrado como um agente promissor na atenuação da lesão causada pela isquemia/reperfusão (IR). O objetivo deste estudo foi determinar os efeitos protetores do ácido ascórbico na morfologia intestinal durante a IR em ratos. MATERIAL E MÉTODOS: Examinamos alterações morfológicas no intestino delgado de ratos do tipo Wistar. Após 40 minutos de isquemia (I), isquemia seguida de reperfusão (IR), isquemia com tratamento com ácido ascórbico (IA), isquemia seguida por 30 minutos de reperfusão e tratamento com ácido ascórbico (IRA) e do grupo sham (S). Utilizamos a morfometria para avaliar quantitativamente a arquitetura dos vilos da mucosa intestinal, criptas intestinais, necrose, hemorragia, células inflamatórias nas bordas mesentéricas e antimesentéricas do intestino delgado. RESULTADOS: O ácido ascórbico causou uma redução significativa (p<0,05) no infarto hemorrágico dos vilos intestinais da borda antimesentérica do intestino delgado após isquemia seguida por reperfusão, bem como redução da necrose dos vilos em ambas as bordas após a isquemia (p<0.05). As lesões presentes no intestino delgado foram mais proeminentes na borda antimesentérica. CONCLUSÕES: O pré-tratamento com ácido ascórbico atenuou ou reduziu significativamente as alterações morfológicas no intestino delgado induzidas pela isquemia-reperfusão

    Anti-group A streptococcal vaccine epitope : Structure, stability, and its ability to interact with HLA class II molecules

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    Streptococcus pyogenes infections remain a health problem in several countries due to poststreptococcal sequelae. We developed a vaccine epitope (StreptInCor) composed of 55 amino acids residues of the C-terminal portion of the M protein that encompasses both T and B cell protective epitopes. The nuclear magnetic resonance (NMR) structure of the StreptInCor peptide showed that the structure was composed of two microdomains linked by an 18-residue α-helix. A chemical stability study of the StreptInCor folding/unfolding process using far-UV circular dichroism showed that the structure was chemically stable with respect to pH and the concentration of urea. The T cell epitope is located in the first microdomain and encompasses 11 out of the 18 α-helix residues, whereas the B cell epitope is in the second microdomain and showed no α-helical structure. The prediction of StreptInCor epitope binding to different HLA class II molecules was evaluated based on an analysis of the 55 residues and the theoretical possibilities for the processed peptides to fit into the P1, P4, P6, and P9 pockets in the groove of several HLA class II molecules. We observed 7 potential sites along the amino acid sequence of StreptInCor that were capable of recognizing HLA class II molecules (DRB1*, DRB3*, DRB4*, and DRB5*). StreptInCor- overlapping peptides induced cellular and humoral immune responses of individuals bearing different HLA class II molecules and could be considered as a universal vaccine epitope. © 2011 by The American Society for Biochemistry and Molecular Biology, Inc

    StreptInCor: a candidate vaccine epitope against S. pyogenes infections induces protection in outbred mice.

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    Infection with Streptococcus pyogenes (S. pyogenes) can result in several diseases, particularly in children. S. pyogenes M protein is the major virulence factor, and certain regions of its N-terminus can trigger autoimmune sequelae such as rheumatic fever in susceptible individuals with untreated group A streptococcal pharyngitis. In a previous study, we utilized a large panel of human peripheral blood cells to define the C-terminal protective epitope StreptInCor (medical identity), which does not induce autoimmune reactions. We recently confirmed the results in HLA-transgenic mice. In the present study, we extended the experimental assays to outbred animals (Swiss mice). Herein, we demonstrate high titers of StreptInCor-specific antibodies, as well as appropriate T-cell immune responses. No cross-reaction to cardiac myosin was detected. Additionally, immunized Swiss mice exhibited 87% survival one month after challenge with S. pyogenes. In conclusion, the data presented herein reinforce previous results in humans and animals and further emphasize that StreptInCor could be an effective and safe vaccine for the prevention of S. pyogenes infections
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