Exercise reduces cellular stress related to skeletal muscle insulin resistance

This study sought to evaluate the effects of a single session of exercise on the expression of Hsp70, of c-jun N-terminal kinase (JNK), and insulin receptor substrate 1 serine 612 (IRS(ser612)) phosphorylation in the skeletal muscle of obese and obese insulin-resistant patients. Twenty-seven volunteers were divided into three experimental groups (eutrophic insulin-sensitive, obese insulin-sensitive, and obese insulin-resistant) according to their body mass index and the presence of insulin resistance. The volunteers performed 60 min of aerobic exercise on a cycle ergometer at 60 % of peak oxygen consumption. M. vastus lateralis samples were obtained before and after exercise. The protein expressions were evaluated by Western blot. Our findings show that compared with paired eutrophic controls, obese subjects have higher basal levels of p-JNK (100 ± 23 % vs. 227 ± 67 %, p = 0.03) and p-IRS-1(ser612) (100 ± 23 % vs. 340 ± 67 %, p < 0.001) and reduced HSP70 (100 ± 16 % vs. 63 ± 12 %, p < 0.001). The presence of insulin resistance results in a further increase in p-JNK (460 ± 107 %, p < 0.001) and a decrease in Hsp70 (46 ± 5 %, p = 0.006), but p-IRS-1(ser612) levels did not differ from obese subjects (312 ± 73 %, p > 0.05). Exercise reduced p-JNK in obese insulin-resistant subjects (328 ± 33 %, p = 0.001), but not in controls or obese subjects. Furthermore, exercise reduced p-IRS-1(ser612) for both obese (122 ± 44 %) and obese insulin-resistant (185 ± 36 %) subjects. A main effect of exercise was observed in HSP70 (p = 0.007). We demonstrated that a single session of exercise promotes changes that characterize a reduction in cellular stress that may contribute to exercise-induced increase in insulin sensitivity.

Molecular cloning, characterization and expression of the heat shock protein 60 gene from the human pathogenic fungus Paracoccidioides brasiliensis

A gene encoding the heat shock protein (HSP) 60 from Paracoccidioides brasiliensis (Pb) was cloned and characterized. The hsp60 gene is composed of three exons divided by two introns. Structural analysis of the promoter detected canonical sequences characteristic of regulatory regions from eukaryotic genes. The deduced amino acid sequence of the Pb hsp60 gene and the respective cloned cDNA consists of 592 residues highly homologous to other fungal HSP60 proteins. The hsp60 gene is present as a single copy in the genome, as shown by Southern blot analysis. The HSP60 protein was isolated from Pb yeast cellular extracts. N-terminal amino acid sequencing of HSP60 confirmed that the cloned hsp60 gene correlated to the predicted protein in Pb. HSP60 expression appeared to be regulated during form transition in Pb, as different levels of expression were detected in in vitro labeling of cells and northern blot analysis. The complete coding region of Pb hsp60 was fused with plasmid pGEX-4T-3 and expressed in Escherichia coli as a glutathione S-transferase-tagged recombinant protein. The protein reacted with a mouse monoclonal antibody raised to a human recombinant HSP60. Western immunoblot experiments demonstrated that the recombinant protein and the native HSP60 were recognized by sera from humans with paracoccidioidomycosis (PCM).

Nontoxic, mutagenic, and clastogenic activities of Mate-Chimarrão (Ilex paraguariensis)

Aqueous extracts of Ilex paraguarariensis (mate-chimarrão), a species that belongs to the Aquifoliaceae family, were analyzed for the presence of genotoxic, mutagenic, and clastogenic activities through bacterial trials based on the induction of the SOS functions, as well as in human lymphocytes in vitro and in mammalian cells in vivo. The extracts of mate-chimarrão were genotoxic, as assessed by lysogenic induction in Escherichia coli, and they also induced mutagenesis in Salmonella typhimurium. They addition of S9 microsomal fraction, catalase, thiourea, or dipyridyl counteracted the genotoxic activity of mate-chimarrão, suggesting that oxygen reactive species play an essential role in the genotoxicity of mate-chimarrão extracts. The extracts were not clastogenic in vivo (bone marrow cells of rats) in our experimental conditions, but we have observed an increased frequency of chromosomal aberrations in mate-chimarrão-treated human peripheral lymphocytes. Our results suggest that a high consumption of mate-chimarrão can potentiate carcinogenesis in the human oropharynx and esophagus.

Plasma cell granuloma of the larynx as a cause of sudden asphyxial death

A unique case of plasma cell granuloma of the larynx associated with sudden death in a young HIV-positive woman is described. The plasma cell infiltration fulfilled the criteria for plasma cell granuloma, showing characteristic histologic and immunohistochemical features (polyclonality). A review of the most recent literature is provided.

[Behavior disorders with predominance of aggressiveness, irritability, impulsiveness and instability. Clinical-electroencephalographic study of 100 cases]

Este trabalho destinou-se a verificar a freqüência dos fatores etiológicos que podem atuar em casos de distúrbios de conduta quando os sintomas básicos são irritabilidade, agressividade, impulsividade e instabilidade psico-motora. Foram revistas 100 observações de pacientes menores, de ambos os sexos, com idade variando entre 5 a 16 anos, atendidos no Ambulatório do Serviço de Psiquiatria Infantil do Hospital de Psiquiatria da Faculdade de Medicina da Universidade de São Paulo. Em 15 pacientes não foi possível evidenciar circunstâncias ou fatores orgânicos que pudessem estar diretamente relacionados à etiologia dos citados distúrbios. Nos demais, foram encontrados fatores etiológicos provavelmente relacionados com o quadro clínico, na seguinte freqüência: disritmia cerebral, em 69 casos; condições ambientais desfavoráveis, em 37 casos; oligofrenia, em 35 casos; sofrimento cerebral, em 3 casos. A importância dos fatores ambientais e da oligofrenia na gênese dos distúrbios de conduta já é plenamente conhecida e por isso não surpreende a freqüência com que foram encontrados. Inesperada, no entanto, foi a alta incidência de disritmia cerebral nesta casuística: 68% contra mais ou menos 10% encontrados na população em geral, segundo os estudos de eletrencefalografia e epilepsia. Diferença tão grande dispensa análise estatística e indica um fator de extrema importância na origem dos distúrbios de conduta que, entretanto, não costuma ser valorizado e nem mesmo citado nos estudos sobre esse tema. As conclusões deste trabalho sugerem uma revisão na terapêutica dos distúrbios de conduta. Ao lado dos métodos pedagógicos e psicoterápicos, únicos habitualmente recomendados, deve ser incluído o tratamento antiepilético, uma vez que, em nossa experiência esta pode dar ótimos resultados sobre a irritabilidade, a agressividade, a impulsividade e a instabilidade manifestadas em pacientes com disritmia cerebral.