138 resultados para Sorbitol dehydrogenase
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Pós-graduação em Pediatria - FMB
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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
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The N-terminus of the human dihydroorotate dehydrogenase (HsDHODH) has been described as important for the enzyme attachment in the inner mitochondrial membrane and possibly to regulate enzymatic activity. In this study, we synthesized the peptide acetyl-GDERFYAEHLMPTLQGLLDPESAHRL AVRFTSLGamide, comprising the residues 33-66 of HsDHODH N-terminal conserved microdomain. Langmuir monolayers and circular dichroism (CD) were employed to investigate the interactions between the peptide and membrane model, as micelles and monolayers of the lipids phosphatidylcholine (PC), 3-phosphatidylethanolamine (PE) and cardiolipin (CL). These lipids represent the major constituents of inner mitochondrial membranes. According to CD data, the peptide adopted a random structure in water, whereas it acquired α-helical structures in the presence of micelles. The π–A isotherms and polarization- modulated infrared reflection-absorption spectroscopy on monolayers showed that the peptide interacted with all lipids, but in different ways. In DPPC monolayers, the peptide penetrated into the hydrophobic region. The strongest initial interaction occurred with DPPE, but the peptide was expelled from this monolayer at high surface pressures. In CL, the peptide could induce a partial dissolution of the monolayer, leading to shorter areas at the monolayer collapse. These results corroborate the literature, where the HsDHODH microdomain is anchored into the inner mitochondrial membrane. Moreover, the existence of distinct conformations and interactions with the different membrane lipids indicates that the access to the enzyme active site may be controlled not only by conformational changes occurring at the microdomain of the protein, but also by some lipid-protein synergetic mechanism, where the HsDHODH peptide would be able to recognize lipid domains in the membrane. - See more at: http://www.eurekaselect.com/122062/article#sthash.1ZZbc7E0.dpuf
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Microorganisms living in the saliva are able to ferment some sweetener types and to promote the fall of pH that has its critical point around 5.5; in this situation, they equal the input and the calcium output in the processes of remineralization and demineralization. For iteration of the three essential factors to the installation of the dental caries (microorganism, host and diet) suggested the accomplishment of a work that involved one of these factors. This work aims to study this issue, through the indication of substitute sweetener of the saccharose, whenever possible, it solved to evaluate pH of the saliva, exposed to sorbitol.
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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
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The objective of this study was to assess the effect of 0.05% sodium fluoride solutions containing 2.5% or 12.5% xylitol on the number of Streptococcus mutans in the human mouth. Fifty boys between 8 and 16 years of age participated in this double-blind crossover study. Of the original 50 boys, 33 finished the study. Participants were randomly divided into four groups. The following solutions were employed: placebo solution; 0.05% sodium fluoride solution; 0.05% sodium fluoride + 2.5% xylitol + 2% sorbitol; 0.05% sodium fluoride + 12.5% xylitol + 2% sorbitol. Each solution was used for a 28-day period (20 mL/day, twice a day), with a 10-day washout period between solutions. There were no significant differences (P = 0.32) between the two xylitol-containing solutions (2.5% vs. 12.5%) concerning the number of Streptococcus mutans. However, there was a significant difference between these two xylitol-containing solutions and the sodium fluoride and placebo solutions (P < 0.001). Our results suggest that the 0.05% sodium fluoride solutions containing either 2.5% or 12.5% xylitol caused a significant reduction in the number of Streptococcus mutans.
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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 alcohol dehydrogenase (ADH) was purified from dry baker’s yeast. This is a key enzyme of the primary short-chain alcohol metabolism in many organisms. In the present study, the obtained enzymatic preparation of baker’s yeast, containing 2.7 U/mg of ADH, was used in the reactions. The purified extract of the ADH obtained from Fermix commercial dry yeast, presented the highest activity and purification factor when ammonium sulfate was added in the precipitation of protein, in the range 35-60% (w/v). The enzymatic preparation was maintained for 2 months in the lyophilized form at 4ºC (retention of 96.2% of activity) in the presence of 1 mmol/L of sodium azide, and it maintained 47% of activity for 30 days at 30°C in the presence of 15% PEG. The assays of ethanol (detection range 5 mM -150 mM or 2.3 x 10-4 – 6.91 x 10-3g/L) in different samples in alcoholic beverages, presented a maximum deviation of only 2.1%. Assays of recovery of the substrate (99.25%) added in the wine showed that the methodology is viable for this sample type. The standard curve and the analytic curve of this method meet the conditions of precision, sensitivity, simplicity, and low cost, required for a useable analytical method.
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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)
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Piracanjuba (Brycon orbignyanus) is a Brazilian migratory fast-growing omnivore, very appreciated as a sport fish, which is threatened to extinction in Southern Brazil due to stock over exploitation and dam building. Therefore, efforts have been made to raise this fish in captivity for reintroduction and aquaculture purposes. In the present study, the effects of different dietary protein and lipid concentrations on piracanjuba fingerlings growth performance, feed utilization, body composition, hepatosomatic index (HSI) and activity of the lipogenic enzymes fatty acid synthetase (FAS), glucose-6-phosphate dehydrogenase (G6PD) and malic enzyme (ME) were investigated using a 2 x 3 factorial experiment. Six casein-gelatin based diets were prepared combining two protein (30% and 32%) and three lipid concentrations (5.5%, 8.8% and 12.1%). Eleven fish, average weight 11.30 +/- 0.1 g, were held in each of 18 100-1 aquaria, supplied with recirculating freshwater. Each diet was randomly assigned to triplicate groups of fish and fed to apparent satiation, twice a day for 100 d. Piracanjuba fingerlings' daily weight gain (0.36-0.40 g), specific growth rate (1.43-1.51%), feed utilization and HSI were not influenced by dietary protein or lipid concentration. However, body composition was directly affected by dietary treatment. An increase in body fat and dry matter was observed as dietary lipid increased, for both dietary protein concentrations tested. The activity of FAS was depressed by increasing dietary fat levels but the G6PD activity did not differ among dietary treatments, although ME activity showed some regulation by dietary protein. These results indicate that an increase from 5.5% to 12.1% in the dietary lipid, at a dietary protein concentration of 30% or 32%, promotes body fat accumulation in piracanjuba fingerlings with no improvement in growth, suggesting that the lipid requirement for this species should be 5% or less, when raised for commercial purposes. However, the additional energy reserve from body fat accumulation could be desirable for piracanjuba fingerlings produced for stock enhancement. (C) 2003 Editions scientifiques et medicales Elsevier SAS and Ifremer/IRD/Inra/Cemagref. All rights reserved.
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Adubos verdes (AVs) são condicionadores do solo utilizados para a melhoria da estrutura e fertilidade do solo. Este estudo avaliou o efeito de Crotalaria spectabilis Roth (crotalária), Cajanus cajan (L) Millsp (guandu) e Brachiaria decumbens Stapf (braquiária) nas propriedades microbiológicas e bioquímicas do solo sob laranjal. As leguminosas foram plantadas nas entrelinhas do laranjal e, após 3 meses, cortadas e lançadas nas entrelinhas. A braquiária, já estabelecida, foi roçada e lançada nas entrelinhas. Após 5 meses, as amostras de solo foram coletadas na entrelinha e na linha, na profundidade de 0-20 cm. O delineamento experimental foi em parcela subdividida. Efeito significativo (p< 0,05%) da aplicação dos AV sobre as contagens de bactérias, as atividades da desidrogenase e nitrificante foram obtidas e aumentaram, em média, de 20, 39 e 190%, respectivamente. O número de fungos diminuiu de 57%. A atividade da urease e a solubilizadora, e os conteúdos de matéria orgânica e umidade não foram influenciados pela aplicação dos AVs. Dentre as plantas, respostas significativas foram obtidas decorrentes do estímulo da atividade da desidrogenase em 57% pelo guandu, da urease em 58% pela braquiária, solubilizadora em 346% pela crotalária e nitrificante em 236% pelo guandu ou braquiária em relação aos demais AVs. Estes resultados sugerem que a aplicação de AVs durante anos consecutivos pode estimular a ação dos microrganismos e melhorar a qualidade do solo.
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As efusões são problemas clínicos frequentes e que ocorrem em consequência de uma enfermidade que culmine com diminuição da pressão coloidosmótica intravascular, elevação da pressão hidrostática local, aumento da permeabilidade vascular e/ou comprometimento da drenagem realizada pelos vasos linfáticos. Dessa maneira, a avaliação laboratorial desse fluido torna-se relevante para que, em conjunto com os sinais clínicos apresentados pelo paciente, possa ser firmado um possível diagnóstico e instituída ação terapêutica adequada. Assim sendo, a classificação de uma efusão em transudato ou exsudato torna-se um dos pontos críticos para a elucidação do diagnóstico e condução do caso clínico. em Medicina Veterinária, o método tradicional de classificação de uma efusão é baseado na contagem celular e na concentração de proteínas do fluido. Contudo, diversos estudos evidenciam que tais parâmetros não são suficientes para a correta classificação de todas as efusões. Assim, o presente estudo foi conduzido com o objetivo de verificar a correlação de outros parâmetros bioquímicos com a diferenciação das efusões transudativas e exsudativas e, para tal, foram avaliadas as atividades de lacatato desidrogenase (LDH) das efusões, a relação de sua atividade fluido/soro, concentração de lactato das efusões, o gradiente de concentração de lactato do soro para o fluido e a concentração de proteínas das efusões. Os resultados obtidos permitiram observar que a atividade de LDH, a relação LDH efusão/soro, a concentração de lactato e o gradiente de concentração de lactato soro/efusão apresentam diferença estatisticamente significativa (P<0,05), bem como alta correlação com a classificação de uma efusão exsudativa.
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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)