4,064 research outputs found
Human Th17 cells
The discovery in mice of a new lineage of CD4+ effector T helper (Th) cells that selectively produce IL-17 has provided exciting new insights into immune regulation, host defence, and the pathogenesis of autoimmune and other chronic inflammatory disorders. This population of CD4+ Th cells, which has been termed 'Th17', indeed plays an apparently critical role in the pathogenesis of some murine models of autoimmunity. Interestingly, murine Th17 cells share a common origin with Foxp3+ T regulatory cells, because both populations are produced in response to transforming growth factor-β, but they develop into Th17 cells only when IL-6 is simultaneously produced. Initial studies in humans have confirmed the existence of Th17 cells, but they have shown that the origin of these cells in humans differs from that in mice, with IL-1β and IL-23 being the major cytokines responsible for their development. Moreover, the presence in the circulation and in various tissues of Th cells that can produce both IL-17 and interferon-γ, as well as the flexibility of human Th17 clones to produce interferon-γ in addition to IL-17 in response to IL-12, suggests that there may be a developmental relationship between Th17 and Th1 cells, at least in humans. Resolving this issue has great implications in tems of establishing the respective pathogenic roles of Th1 and Th17 cells in autoimmune disorders. In contrast, it is unlikely that Th17 cells contribute to the pathogenesis of human allergic IgE-mediated disorders, because IL-4 and IL-25 (a powerful inducer of IL-4) are both potent inhibitors of Th17 cell development
Natação Escolar E Desenvolvimento Motor De Crianças Do Primeiro Ciclo De Ensino
TCC (Graduação) - Universidade Federal de Santa Catarina - Centro de Desportos - Educação Física - Licenciatura.O presente estudo teve como objetivo verificar se a natação escolar figura como uma possibilidade de intervenção pedagógica para potencializar o desenvolvimento motor de crianças do primeiro ciclo de ensino. A pesquisa caracterizou-se como uma pesquisa de campo com delineamento transversal, quantitativo. A população do presente estudo foi composta por alunos que tinham aulas de Educação Física com natação, do Centro Educacional de Barreiros, e por alunos com aluna de Educação Física sem natação, da Escola Adventistas da cidade de Florianópolis. A amostra do presente estudo foi constituída por 33 crianças de ambos os sexos, na faixa etária de 6 a 10 anos de idade. Foi utilizada para a avaliação a Escala do Desenvolvimento Motor do Rosa Neto (2002), com intuito de verificar o nível de desenvolvimento motor de crianças, obtendo um perfil do desenvolvimento destes grupos. Para a análise dos dados foram utilizados procedimentos de estatística descritiva e inferencial, com valor de significância em p≤0,05. Para a comparação dos resultados desenvolvimentistas foi utilizado o teste t de medidas independentes realizado no pacote estatístico SPSS v.22. De maneira geral, o desenvolvimento do presente estudo demonstrou os alunos da escola que tem a natação inserida em suas aulas de Educação Física apresentaram melhor desenvolvimento motor geral que seus pares sem natação na Educação Física
Heterogeneity of human effector CD4+ T cells
For many years the heterogeneity of CD4+ T-helper (Th) cells has been limited to Th1 and Th2 cells, which have been considered not only to be responsible for different types of protective responses, but also for the pathogenesis of many disorders. Th1 cells are indeed protective against intracellular microbes and they are thought to play a pathogenic role in organ-specific autoimmune and other chronic inflammatory disorders. Th2 cells provide protection against helminths, but are also responsible for the pathogenesis of allergic diseases. The identification and cloning of new cytokines has allowed one to enlarge the series of functional subsets of CD4+ Th effector cells. In particular, CD4+ Th cells producing IL-17 and IL-22, named Th17, have been initially implicated in the pathogenesis of many chronic inflammatory disorders instead of Th1 cells. However, the more recent studies in both humans and mice suggest that Th17 cells exhibit a high plasticity toward Th1 cells and that both Th17 and Th1 cells may be pathogenic. More recently, another two subsets of effector CD4+ Th cells, named Th9 and Th22 cells, have been described, even if their pathophysiological meaning is still unclear. Despite the heterogeneity of CD4+ effector Th cells being higher than previously thought and some of their subsets exhibiting high plasticity, the Th1/Th2 paradigm still maintains a strong validity
- …