776 resultados para catalase
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A identificação de fatores de risco para colonização vaginal materna por Streptococcus agalactiae tem sido objeto de estudo na literatura mundial pois essa colonização frequentemente é assintomática e pode causar bacteremia nos recémnascidos, com significante morbidade e mortalidade, especialmente em prematuros. O objetivo do estudo foi associar a colonização por S. agalactiae com o padrão da microbiota vaginal das gestantes e avaliar a eficácia de swabs combinados na detecção de S. agalactiae. Foram incluídas no estudo 405 gestantes em idade gestacional entre 35 e 37 semanas, atendidas no Pré-Natal do Hospital das Clínicas da Faculdade de Medicina de Botucatu, UNESP. Utilizando-se swabs estéreis foram obtidas amostras da região anorretal, do intróito vaginal e do terço distal da parede vaginal. O material coletado foi cultivado em caldo Todd Hewit suplementado com colistina (10g/mL) e ácido nalidíxico (15g/mL), por 18 a 24 horas à 37oC, em seguida, realizada subcultura em ágar-sangue a 5% sob as mesmas condições. As colônias sugestivas de S. agalactiae foram submetidas a coloração de Gram e ao teste da catalase e ao CAMP test. O padrão de microbiota vaginal foi avaliado empregandose a técnica de coloração de Gram. Os dados sócio-demográficos e obstétricos foram obtidos por formulário próprio. Considerando como variável resposta a colonização materna ou não por S. agalactiae, foi ajustado um modelo de regressão logística adotando o método stepwise, considerando as variáveis explanatórias quantitativas e qualitativas. Para positividade de cultura em swabs combinados e isolados foi empregado o teste de Tukey. colonização materna por S. agalactiae foi de 25,4%. Em relação à microbiota vaginal, as alterações mais freqüentes foram vaginose citolítica (11,3%) seguido de vaginose bacteriana (10,9%), candidíase (8,2%) e Flora II ...(Resumo completo, clicar acesso eletrônico abaixo)
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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)
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Sickle cell anemia (SCA) shows a pathophysiology that involves multiple changes in sickle cell erythrocytes, vaso-occlusive episodes, hemolysis, activation of inflammatory mediators, endothelial cell dysfunction, and oxidative stress. These events complicate treatment and culminate in the development of manifestations such as anemia, pain crises and multiorgan dysfunction. The aim of this study was to evaluate, in SCA patients, oxidative stress and antioxidant capacity markers, correlating them to treatment with hydroxyurea (HU), β-globin haplotypes and glutathione S-transferase polymorphisms (GSTT1, GSTM1 and GSTP1), in comparison to a control group (CG). The study groups were composed of 48 individuals without hemoglobinopathies (CG), SCA patients treated with HU [AF (+HU), N = 13] and untreated SCA patients [AF (-HU), N = 15], after informed consent. The groups were analyzed using cytological, electrophoretic, chromatographic and molecular methods and information from medical records. The GSTM1 and GSTT1 polymorphisms were determined by multiplex PCR, while the GSTP1 polymorphism by PCR-RFLP. Biochemical parameters were measured using spectrophotometric methods [TBARS, TEAC and catalase (CAT) and GST activities] and a chromatographic method [glutathione (GSH)]. The fetal Hb (Hb F) levels observed in the SCA (+HU) group (10.9%) confirmed the already well-described pharmacological effect of HU, but the SCA (-HU) group also had high Hb F levels (6.1%), which may have been influenced by genetic factors not targeted in this study. We found a higher frequency of the Bantu haplotype (48.2%), followed by the Benin (32.1%) and also Cameroon haplotypes, rare in our population, and 19.7% of atypical haplotypes. The presence of Bantu haplotype was related to higher lipid peroxidation levels in patients, but also, it conferred a differential response to HU treatment, raising Hb F levels in 52.6% (P = 0.03). The protective effect of Hb F was confirmed, because the increase in their levels resulted in a 41.3% decrease in lipid peroxidation levels (r = -0.74, P = 0.0156). The genotypic frequency of the GST polymorphisms observed was similar to that of other studies in the Brazilian population, and its association with biochemical markers revealed a significant difference only for the GSTP1 polymorphism, where patients with genotype V/V showed higher GSH and TEAC levels (P = 0.04 and P = 0.03, respectively) compared to patients with genotype I/I. The TBARS levels were about five to eight times higher in the SCA (+HU) and SCA (-HU) groups, respectively, compared to controls, and HU produced a 35.2% decrease in lipid peroxidation levels in the SCA (+HU) group (P < 0.0001). Moreover, the SCA (+HU) group showed higher TEAC levels when compared to CG (P = 0.002). We did not find any significant difference in GST activity between the groups studied (P = 0.76), but CAT activity was about 17 and 30% lower in SCA (+HU) and SCA (-HU) groups, respectively (P < 0.00001). Plasma GSH levels were ~2 times higher in SCA patients than in the control group (P = 0.0005) and showed a positive correlation with TBARS levels, confirming its antioxidant function. HU treatment contributed to higher CAT activity and TEAC levels and lower lipid peroxidation, and its pharmacological effect showed a “haplotype-dependent” response. These findings may contribute to elucidating the potential of HU in ameliorating oxidative stress in SCA subjects.
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Turtles are among the most endangered vertebrate groups, and the main threats to populations are environmental pollution and habitat degradation. The species Phrynops geoffroanus, popularly known as “Geoffroy’s side-necked turtle”, has proliferated in polluted environments, where adverse conditions could influence their living habits and physiological condition. Studies that monitor the effects of environmental pollution are key to understanding the species’ biology and designing effective conservation strategies. Thus, the analysis of hematological and biochemical parameters has been shown to be important in assessing the health of wild animals and risks for the animal and ecosystem. This study aimed to assess the environmental influence on the physiology of a P. geoffroanus population through the evaluation of antioxidant status and responses to environmental stressors, compared to specimens from a place under controlled conditions. Blood samples of 60 specimens were collected, 30 from the Felicidade Stream, polluted environment, within the city of São José do Rio Preto, and 30 from the “Reginaldo Uvo Leone” breeding farm, Tabapuã, SP, a place under controlled conditions, whose samples constituted the control group. They were evaluated by hemogram and by determining thiobarbituric acid reactive species (TBARS), Trolox-equivalent antioxidant capacity (TEAC) and the activities of the antioxidant enzymes catalase and glucose-6-phosphate dehydrogenase (G6PDH). There was a wide variation in hematological parameters of P. geoffroanus from the urban environment. The red blood cell count and hemoglobin values were significantly less than those observed in animals from the breeding farm (P = 0.0004; P = 0.0371, respectively). There was a significant increase in the number of thrombocytes (P < 0.0001) and leukocytes (P < 0.0001) in the animals from Felicidade Stream. The stress indices were similar between the two groups (P = 0.4077). TBARS levels showed the cytotoxic potential of compounds in the urban environment, whose animals had elevated levels of lipid peroxidation (P < 0.0001), despite showing a response to environmental damages with increase in antioxidant capacity, as demonstrated by the TEAC assay (P = 0.0207). The lower catalase enzyme activity noted in individuals from the urban environment (P = 0.000184) could be due to the presence of inhibitory compounds. On the other hand, G6PDH activity was higher (P = 0.002962), where this enzyme acts in the generation of NADPH, which is used in several detoxification pathways. We conclude that environmental contamination can increase oxidative damages and generate physiological changes in this species. These data are very useful for the conservation of P. geoffroanus and turtles in general, and confirm that these techniques are effective in monitoring natural regions and that P. geoffroanus can serve as an environmental contamination bioindicator.
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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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This study aimed to assess antioxidant effects of melatonintreatment compared to N-acetylcysteine (NAC) and to their combination in asickle cell suspension. Sickle erythrocytes were suspended in phosphate-buffered saline, pH 7.4, composing external control group. They were alsosuspended and incubated at 37°C either in the absence (experimental controlgroup) or in the presence of NAC, melatonin and their combination atconcentrations of 100 pM, 100 nM and 100 lM for 1 hr (treatment groups).The melatonin influences were evaluated by spectrophotometric [hemolysisdegree, catalase (CAT), glutathione S-transferase (GST), glutathioneperoxidase (GPx), glutathione reductase (GR), glucose-6-phosphatedehydrogenase (G6PDH), and superoxide dismutase (SOD) activities] andchromatographic methods [glutathione (GSH) and malondialdehyde (MDA)levels]. Incubation period was able to cause a rise about 64% on hemolysisdegree as well as practically doubled the lipid peroxidation levels (P < 0.01).However, almost all antioxidants tested treatments neutralized this incubationeffect observed in MDA levels. Among the antioxidant biomarkers evaluated,we observed a modulating effect of combined treatment on GPx and SODactivities (P < 0.01), which showed ~25% decrease in their activities. Inaddition, we found an antioxidant dose-dependent effect for melatonin onlipid peroxidation (r = 0.29; P = 0.03) and for combined antioxidanttreatments also on MDA levels (r = 0.37; P = 0.01) and on SOD activity(r = 0.54; P < 0.01). Hence, these findings contribute with important insightthat melatonin individually or in combination with NAC may be useful forsickle cell anemia management.
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Recent studies have shown a positive association of cancer and obesity, but the morphological and molecular mechanisms involved in this relationship are still unknown. This study analysed the impact of long-term obesity on rat prostate, focusing on stromal changes. Male adult Wistar rats were treated with high-fat diet to induce obesity, while the control group received a balanced diet. After 30 weeks of feeding, the ventral prostate was analysed by immunohistochemistry for cell proliferation, smooth muscle α-actin, vimentin, chondroitin sulphate and metalloproteinases (MMP-2 and 9). The content of androgen receptor (AR), oestrogen receptors (ERs) and vascular endothelial growth factor (VEGF) was measured by Western blotting, and activity of catalase and Glutathione-S-Transferase (GST) were quantified by enzymatic assay. Long-term obesity decreased testosterone plasma levels by 70% and resulted in stromal prostate hyperplasia, as evidenced by increased collagen fibres. Such stromal hyperplasia was associated with increased number of blood vessels and raised VEGF content, and increased expression of chondroitin sulphate, vimentin, α-actin and MMP-9. In spite of the high cell density in prostate, the proliferative activity was lower in the prostates of obese rats, indicating that hyperplasia was established during the early phases in this obesity model. AR levels increased significantly, whereas the ERα decreased in this group. Moreover, the levels of catalase and GST were changed considerably. These findings indicate that long-term obesity, besides disturbing the antioxidant control, causes intense stromal remodelling and release of factors that create an environment that can promote proliferative disorders in the gland, culminating with diffuse hyperplasia.
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Pós-graduação em Biologia Geral e Aplicada - IBB
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Pós-graduação em Ciências fisiológicas
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O pescado e seus derivados têm uma grande importância na dieta, em todo o mundo. Sabe-se que peixes e frutos do mar fortalecem o sistema imunológico, contribuem para a redução dos níveis de colesterol, diminuem as chances de depressão, ajudam na formação dos músculos e protegem contra doenças cardiovasculares. Também, são ricos em vitaminas lipossolúveis A, D e E, além do ômega 3. Muitas vezes, esses produtos são consumidos crus ou com pouco preparo e com isso faz-se necessário medidas higiênico- sanitárias, pois podem ser contaminados com micro-organismos causadores de doenças. A análise microbiológica dos alimentos para se verificar a presença de micro-organismos prejudiciais é fundamental para se conhecer as condições de higiene nas quais estes alimentos foram preparados. Assim, 80 amostras de peixes e frutos do mar de peixarias e supermercados de Botucatu, SP, foram analisadas com o objetivo de verificar se esses alimentos estão dentro dos padrões estabelecidos pela legislação brasileira, através da RDC nº12, através da detecção da presença de Salmonella sp., Staphylococcus aureus e determinação do número mais provável de coliformes termotolerantes (CT), mesmo que este último não faça parte dos parâmetros para esse alimento, mas foi pesquisado para avaliação de suas condições higiênicas. Cada amostra (25 gramas) foi homogeneizada em 225ml de água peptonada e para a detecção de S. aureus, utilizou-se método spread Baird Parker, seguida de catalase, coagulase e kit Dry Spot. Para a detecção de Salmonella, utilizou-se caldo tetrationato (35ºC/24h) e Rapapport (42ºC/24h), semeados em ágar SS e XLD. As colônias foram testadas em TSI, ágar fenilalanina e testadas em poli soros somático e flagelar. Quanto aos CT, empregou-se a técnica de tubos múltiplos, inoculando diluições da amostra em caldo Lauril sulfato, na fase presuntiva e depois em caldo EC (45ºC) na fase confirmatória. De ...
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Pós-graduação em Ciência Animal - FMVA
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Pós-graduação em Agronomia (Horticultura) - FCA
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Pós-graduação em Agronomia (Produção Vegetal) - FCAV
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Pós-graduação em Agronomia (Horticultura) - FCA