Induction of CD4+CD25+FOXP3+ Regulatory T Cells during Human Hookworm Infection Modulates Antigen-Mediated Lymphocyte Proliferation

Hookworm infection is considered one of the most important poverty-promoting neglected tropical diseases, infecting 576 to 740 million people worldwide, especially in the tropics and subtropics. These blood-feeding nematodes have a remarkable ability to downmodulate the host immune response, protecting themselves from elimination and minimizing severe host pathology. While several mechanisms may be involved in the immunomodulation by parasitic infection, experimental evidences have pointed toward the possible involvement of regulatory T cells (Tregs) in downregulating effector T-cell responses upon chronic infection. However, the role of Tregs cells in human hookworm infection is still poorly understood and has not been addressed yet. In the current study we observed an augmentation of circulating CD4+CD25+FOXP3+ regulatory T cells in hookworm-infected individuals compared with healthy non-infected donors. We have also demonstrated that infected individuals present higher levels of circulating Treg cells expressing CTLA-4, GITR, IL-10, TGF-β and IL-17. Moreover, we showed that hookworm crude antigen stimulation reduces the number of CD4+CD25+FOXP3+ T regulatory cells co-expressing IL-17 in infected individuals. Finally, PBMCs from infected individuals pulsed with excreted/secreted products or hookworm crude antigens presented an impaired cellular proliferation, which was partially augmented by the depletion of Treg cells. Our results suggest that Treg cells may play an important role in hookworm-induced immunosuppression, contributing to the longevity of hookworm survival in infected people

Famílias cuidadoras de pessoa idosa: relação com instituições sociais e de saúde

Trata-se de pesquisa de cunho qualitativo que teve como objetivo compreender a relação de famílias de classe popular cuidadoras de idoso fragilizado com as instituições sociais e de saúde. A metodologia utilizada é o Estudo de Caso do Tipo Etnográfico. A coleta de dados foi realizada com Observação Participante e Entrevista com quatro famílias. Através da análise de conteúdo foram identificados três temas: o suporte social, a relação com os serviços de saúde, a relação com a unidade sanitária local. As famílias destacam que o acesso aos serviços de saúde é sofrível e ressaltam a urgência em solidificar o Sistema Único de Saúde, em busca da concretização dos seus princípios

Electrically conductive silicon oxycarbide thin films prepared from preceramic polymers

This work focuses on silicon oxycarbide thin film preparation and characterization. The Taguchi method of experimental design was used to optimize the process of film deposition. The prepared ceramic thin films with a thickness of c. 500 nm were characterized concerning their morphology, composition, and electrical properties. The molecular structure of the preceramic polymers used for the preparation of the ceramic thin films as well as the thermomechanical properties of the resulting SiOC significantly influenced the quality of the ceramic films. Thus, an increase in the content of carbon was found beneficial for the preparation of crack-free thin films. The obtained ceramic films exhibited increased electrical conductivity as compared to monolithic SiOC of similar chemical composition. This was shown to correlate with the unique hierarchical microstructure of the SiOC films, which contain large oxygen-depleted particles, mainly consisting of highly graphitized carbon and SiC, homogeneously dispersed in an oxygen-containing amorphous matrix. The matrix was shown to also contain free carbon and to contribute to charge carrier transport between the highly conductive large particles. The ceramic thin films possess electrical conductivities in the range from 5.4 to 8.8 S/cm and may be suitable for implementation in miniaturized piezoresistive strain gauges