900 resultados para Immune Suppression
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Considering that counting the percentage of CD4 T lymphocytes can add prognostic information regarding patients infected with HIV, the aim of this study was to evaluate the percentage values of CD4+ T lymphocytes from 81 patients determined by flow cytometry and estimated by flow cytometry in conjunction with a hematology counter. Means were compared through the Student's t-test. Pearson's correlation was determined, and the agreement between results was tested by Bland-Altman. The level of significance was P < 0.05. It was found a significantly higher mean difference between the relative values of CD4+ T lymphocytes to the hematologic counter (P < 0.05), for all strata studied. Positive and significant correlations (P < 0.01) were found between the strata CD4 < 200 cells/mL (r = 0.93), between 200 and 500 cells/mL (r = 0.65), and >500 cells/mL (r = 0.81). The limits of agreement were 1.0 +/- 3.8% for the stratum of CD4 < 200 cells/mL, approximately 2.2 +/- 13.5% for the stratum of CD4 between 200 and 500 cells/mL, and approximately 6.2 +/- 20.4% for the stratum > 500 cells/mL. The differences in the percentages of CD4+ T lymphocytes obtained by different methodologies could lead to conflict when used in clinical decisions related to the treatment and care of people infected with HIV.
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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
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An essential key to pathogenicity in Yersinia is the presence of a 70 kb plasmid (pYV) which encodes a type-III secretion system and several virulence outer proteins whose main function is to enable the bacteria to survive in the host. Thus, a specific immune response is needed in which cytokines are engaged. The aim of this study was to assess the influence of Yersinia outer proteins (Yops) released by Yersinia pseudotuberculosis on the production of the proinflammatory cytokines, interleukin-12 (IL-12), and tumor necrosis factor alpha (TNF-alpha), and nitric oxide (NO) by murine peritoneal macrophages. To this end, female Swiss mice were infected intravenously with wild-type Y pseudotuberculosis or with mutant strains unable to secrete specific Yops (YopE, YopH, YopJ, YopM, and YpkA). on the 7th, 14th, 21st, and 28th days after infection, the animals were sacrificed and the cytokines and NO were assayed in the peritoneal macrophages culture supernatants. A fall in NO production was observed during the course of infection with all the strains tested, though during the infection with the strains that did not secrete YopE and YopH, the suppression occurred later. There was, in general, an unchanged or sometimes increased production of TNF-alpha between the 7th and the 21st day after infection, compared to the control group, followed by an abrupt decrease on the last day of infection. The IL-12 production was also suppressed during the infection, with most of the strains tested, except with those that did not secrete YopJ and YopE. The results suggest that Yops may suppress IL-12, TNF-alpha, and NO production and that the most important proteins involved in this suppression are YopE and YopH. (C) 2004 Elsevier B.V. All rights reserved.
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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
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Em agosto de 1983, os Autores, estudaram 36 doentes com infecção causada pelo Plasmodium falciparum e 14 indivíduos normais, nascidos na região de Humaitá, que nunca tiveram malária, sem esplenomegalia, com exame parasitológico de sangue e hemaglutinação passiva negativas. Todos eles foram submetidos à observação clínica completa, exame hematológico, exame parasitológico de sangue e tipagem de linfócitos. Os linfócitos foram isolados e congelados em nitrogênio líquido, para posterior tipagem pela formação de rosetas. Os doentes foram classificados em dois grupos de acordo com a presença (13 doentes), ou ausência (23 doentes) de gametócitos antes do tratamento. Houve predomínio de formas graves no grupo de doentes sem gametócitos. Os resultados mostraram diminuição do número de linfócitos T em ambos os grupos de doentes, com ou sem gametócitos antes do tratamento, enquanto que o número de linfócitos B foi normal apenas no grupo de doentes com gametócitos. Essas observações, assim como as que foram relatadas pelos Autores anteriormente, permitem associar a presença de gametócitos circulantes com o número normal de células B em doentes com formas leves de malária causada pelo Plasmodium falciparum.
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The immune response to leishmaniasis can result in a polarization of a subpopulation of T lymphocytes, which leads to a different cell phenotype and results in immune protection or exacerbation of the disease. Leishmanias persist in the body both in asymptomatic infections and after treatment, representing risks in terms of immunosuppression. The objective of this study was to evaluate the effects of infection and immunosuppression by dexamethasone associated with pentoxifylline on animal weight, spleen weight, the parasitic load in the spleen and liver, as well as the production of IFN-gamma and IL-10 in spleen cell culture of Balb/c mice infected with Leishmania chagasi. The infection did not alter animal weight gain, but spleen weight and size increased. The immunosuppression, induced by dexamethasone associated with pentoxifylline, affected animal weight gain and weight and size of the spleen (in infected and not infected animals). The immunosuppression did not significantly alter the course of the parasite burden in the spleen and liver. Dexamethasone and pentoxifylline affected the studied cytokine production, but not influenced on Th1/Th2 response in infected animals.
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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
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Cancer is one of the main causes of death in canines and felines, and this fact is probably related to the increase in the longevity of these species. The longer the animals live, the higher the exposure to carcinogenic agents will be. With the high incidence of cancer in companion animals, new studies are currently being performed with the aim of finding therapeutic options which make the complete inhibition of the development of neoplasms in animals possible in the future. The correlation of cyclooxygenase-2 (COX-2) whith the development of cancer opens the way for the use of new therapeutic approaches. This relationship has been suggested based on various studies which established an association between the chronic use of nonsteroidal anti-inflammatory drugs (NSAID) and a decrease in the incidence of colon carcinoma. As cancer progresses, COX-2 participates in the arachidonic acid metabolism by synthesizing prostaglandins which can mediate various mechanisms related to cancer development such as: increase in angiogenesis, inhibition of apoptosis, suppression of the immune response, acquisition of greater invasion capacity and metastasis. Accordingly, overexpression of this enzyme in tumors has been associated with the most aggressive, poor-prognosis cancer types, especially carcinomas. Therefore, treatments which use COX-2 inhibitors such as coxibs, whether administered as single agents or in combination with conventional antineoplastic chemotherapy, are an alternative for extending the survival of our cancer patients.
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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)