338 resultados para Nitroblue tetrazolium (NBT)


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O teste de "nitroblue tetrazolium", apesar de inespeclfico, tem-se mostrado útil no sentido de facilitar diagnóstico diferencial relativo a diversas afecções e, sobretudo, de indicar se determinado processo mórbido é presumivelmente bacteriano. Diante da conveniência de analisar o comportamento dessa prova no que concerne a doenças das mais diferentes naturezas, foi efetuada investigação referente à toxoplasmose adquirida, forma linfoglandular. Quanto à casuística considerada, composta de 26 indivíduos, ficaram detectados valores variáveis de 6% a 50%, mas habitualmente superiores a 17% na vigência de infecção com até quatro meses de duração, de acordo com a época de início das manifestações clínicas. Em face a evoluções já mais prolongadas, as cifras registradas comumente mostraram-se inferiores à por último citada. Nenhum tipo de comprometimento estava presente associadamente, o que permitiu avaliação isenta de ponderáveis influências falseadoras. O estudo efetuado retrata contribuição dotada do intuito de possibilitar eventuais aplicabilidades, do exame em questão, também no âmbito do reconhecimento das enfermidades parasitárias talvez em vigor em determinadas circunstâncias.

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The objective of this study was to evaluate the effects of tetramethylpyrazine (TMP) in combination with arsenic trioxide (As2O3) on the proliferation and differentiation of HL-60 cells. The HL-60 cells were treated with 300 µg/mL TMP, 0.5 µM As2O3, and 300 µg/mL TMP combined with 0.5 µM As2O3, respectively. The proliferative inhibition rates were determined with MTT. Differentiation was detected by the nitroblue tetrazolium (NBT) reduction test, Wright’s staining and the distribution of CD11b and CD14. Flow cytometry was used to analyze cell cycle distribution. RT-PCR and Western blot assays were employed to detect the expressions of c-myc, p27, CDK2, and cyclin E1. Combination treatment had synergistic effects on the proliferative inhibition rates. The rates were increased gradually after the combination treatment, much higher than those treated with the corresponding concentration of As2O3 alone. The cells exhibited characteristics of mature granulocytes and a higher NBT-reducing ability, being a 2.6-fold increase in the rate of NBT-positive ratio of HL-60 cells within the As2O3 treatment versus almost a 13-fold increase in the TMP + As2O3 group. Cells treated with both TMP and As2O3 expressed far more CD11b antigens, almost 2-fold compared with the control group. Small doses of TMP potentiate As2O3-induced differentiation of HL-60 cells, possibly by regulating the expression and activity of G0/G1 phase-arresting molecules. Combination treatment of TMP with As2O3 has significant synergistic effects on the proliferative inhibition of HL-60 cells.

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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

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The relationships between neutrophils oxidative metabolism, cortisol serum levels and worm burden, estimated by fecal egg count (EPG), were studied in sheep naturally infected by gastrointestinal parasites at the end of pregnancy, during lactation, and after weaning. Twenty-two Suffolk sheep three to four year old, of same parity and season of parturition were used. Serum cortisol was determined by radioimmunoassay and the neutrophils oxidative metabolism by the nitroblue tetrazolium (NBT) reduction test. The highest EPG values were observed on the fifth week of lactation while the highest rates of cortisol and reduction of NBT occurred on the fourth week after weaning. A positive correlation (r = 0.52; P<0.01) was observed between the neutrophils capacity to reduce the NBT and the serum cortisol concentration in the pre-parturition period. Otherwise, the neutrophils oxidative metabolism decreased near to the parturition. A negative correlation (r = -0.39; P<0.01) between EPG and NBT reduction test was observed after weaning, which was coincident with the increase in the neutrophils capacity to reduce NBT, indicating that animals showing better immune response after weaning have neutrophils with higher oxidative metabolism and lower worm burden.

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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

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Pós-graduação em Biociências e Biotecnologia Aplicadas à Farmácia - FCFAR

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The purpose of this study was to evaluate the leukocyte count and the oxidative metabolism of neutrophil in Saanen goats during periods of pregnancy, parturition and postpartum. Were used 20 Saanen goats, clinically healthy and serologically negative for caprine arthritis encephalitis virus (CAEV). Blood samples were collected by jugular venipuncture 49 (M1), 42 (M2), 35 (M3), 28 (M4), 21 (M5), 14 (M6), seven (M7), three (M8) days before the parturition, on the day of birth (M9), three (M10) and seven (M11) days postpartum, for the leukocyte count, and serum for cortisol, estradiol and progesterone determination. From 28 days (M4) before parturition until seven days postpartum (M11) blood samples were collected for evaluation of oxidative metabolism of neutrophils by the nitroblue tetrazolium reduction test (NBT). The results showed that at parturition day there were an increase in cortisol and estradiol levels and a decrease in progesterone serum, neutrophilic leukocytosis and left shift slight, decrease of lymphocytes, increase in the neutrophil: lymphocyte, eosinopenia, monocytosis and basophilia. There was a neutrophilic leukocytosis and an increase in the neutrophil: lymphocyte on the seventh day postpartum. There were not significant alterations in oxidative metabolism of neutrophils during pregnancy, parturition and postpartum. It was concluded that parturition causes an elevation in cortisol and estradiol levels and a decrease in progesterone serum determining a neutrophilic leukocytosis and left shift slight, with a reduction of lymphocytes, increase in the neutrophil:lymphocyte, eosinopenia, monocytosis and basophilia. Neutrophilic leukocytosis, increase in the neutrophil: lymphocyte and fibrinogen are detected on the seventh day postpartum. Pregnancy, parturition and the postpartum do not change the oxidative metabolism of neutrophils evaluated by NBT reduction test.

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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

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Leukogram and neutrophil oxidative metabolism from dogs with visceral leishmaniasis (VL) were compared before and after treatment with meglumine antimoniate (AM) and with an association of meglumine antimoniate and allopurinol (AMA). The results obtained demonstrated that neutrophils of dogs with VL do not lose their capacity of reducing NBT and that oxidative metabolism has been more active in the majority of the cases. After treatment with AM and AMA, dogs with VL presented a redution of neutrophils oxidative metabolism, suggesting that this decrease was related with the decrease in the number of parasites and a probable inhibitor effect of these drugs on neutrophils oxidative metabolism.

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Effects of tributyltin (TBT) which has been used for antifouling paint of ship's hulls and fishing nets on the immune system in Japanese flounder (Paralichthys olivaceus) were investigated. After short-term exposure to a high level of TBT, leucocytes in the head kidney from 1-year-old flounder were examined for the proportion of neutrophils in total leucocytes. Also examined were their respiratory burst activities using flow cytometry, the reduction of nitroblue tetrazolium (NBT) and lysozyme activities. Furthermore, long-term exposures to a relatively low level of TBT using young flounder were also carried out. The proportion of neutrophils in total leucocytes prepared from head kidney in each fish exposed to TBT at 20 microg/L for 5 days and the reduction of NBT by leucocytes prepared from the same experimental conditions increase compared to the control group. The contents were 42.0+/-6.8 and 52.5+/-6.3%, respectively. Significant differences of the NBT reduction were observed between 0 and 20 microg/L TBT exposure groups. On the other hand, the respiratory burst activity of cells in the exposure group clearly showed a tendency to decrease compared to the control group. Furthermore, high level of TBT also inhibited lysozyme activity which plays an important role for the bacteriocidal procedures. However, similar results were not obtained in the exposure group with a relatively low level of TBT. To determine the immunotoxic effects of TBT, infection experiments using pathogens which are naturally occurring should be further investigated.

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Respostas imunológicas inatas são úteis para determinar o estado de saúde de peixes e avaliar o efeito de substâncias imunomoduladoras no cultivo destes animais. A atividade respiratória de leucócitos foi medida em pacu (Piaractus mesopotamicus) através de ensaio de quimioluminescência e ensaio de redução do nitroblue tetrazolium (NBT). O ensaio de redução do nitroblue tetrazolium pareceu mais adequado que o ensaio de quimioluminescência para determinação da atividade respiratória de leucócitos, uma vez que foi difícil isolar com êxito os leucócitos do sangue para o ensaio de quimioluminescência. Lisozima sérica e plasmática foram medidas por meio de ensaio turbidimétrico. Com o objetivo de inativar as proteínas do sistema complemento, as amostras de soro e plasma foram aquecidas (56 ºC por 30 minutos). Porém, este procedimento provocou a turvação das amostras de plasma e interferiu nos resultados. A atividade de lisozima no soro foi maior que no plasma, sugerindo que amostras de soro são mais apropriadas para esta análise. Este estudo estabeleceu protocolos que podem ser utilizados como ferramentas no estudo de mecanismos imunológicos do peixe tropical pacu.

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Dissertação (mestrado)—Universidade de Brasília, Faculdade de Medicina, Pós-graduação em Medicina Tropical, 2015.

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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

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The absolute numbers of total leukocytes, lymphocytes, T cells, helper/inducer, suppressor/cytotoxic and B cells were decreased in the peripheral blood of patients with chronic Chagas' disease. Since antilymphocyte antibodies were present only in a minority of patients they probably cannot account for the abnormalities in lymphocyte subsets. Patient neutrophils stimulated with endotoxin-treated autologous plasma showed depressed chemotactic activity and this seems to be an intrinsic cellular defect rather than plasma inhibition. Random migration of neutrophils was normal. Reduction of nitroblue tetrazolium by endotoxin- stimulated neutrophils was also decreased. These findings further document the presence of immunosuppression in human Chagas' disease. They may be relevant to autoimmunity, defense against microorganisms and against tumor cells at least in a subset of patients with more severe abnormalities.

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The efficacy of a marine yeast Candida sake as source of immunostimulant to Indian white shrimp Fenneropenaeus indicus was estimated. Biomass of C. sake was prepared using malt extract agar and incorporated at graded levels into a standard diet to prepare yeast diets of varying biomass concentrations (1%, 10% and 20%). F. indicus were fed on these diets for a period of 28 days and challenged orally with white spot syndrome virus (WSSV) and immune parameters such as total haemocyte count, phenoloxidase and nitroblue tetrazolium reduction (NBT) were determined. Ten per cent C. sake in the diet was found to support an optimum immune response in the animals in general and their enhancement could be observed on the second and third day following challenge with the virus. The study has demonstrated that marine yeast C. sake at 10% in diet (w/w) may be used as an effective source of immunostimulants in F. indicus