188 resultados para LDH-C4


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Isotope screening is a simple test for determining the photosynthetic pathway used by plants. The scope of this work was to classify the photosynthetic type of some herbs and medicinal plants through studies of the carbon isotope composition (δ13C). Also, we propose the use of carbon isotope composition as a tool to control the quality of herbs and medicinal plants. For studies of δ13C, δ 13C‰ = [R (sample)/R (standard) - 1] × 10-3, dry leaves powdered in cryogenic mill were analyzed in a mass spectrometer coupled with an elemental analyzer for determining the ratio R = 13CO2/12CO2. In investigation of δ13C of 55 species, 23 botanical families, and 44 species possessed a C3 photosynthetic type. Six species found among the botanical families Euphorbiaceae and Poaceae were C4 plants, and 5 species found among the botanical families Agavaceae, Euphorbiaceae, and Liliaceae possessed CAM-type photosynthesis. Carbon isotope composition of plants can be used as quality control of herbs and medicinal plants, allowing the identification of frauds or contaminations. Also, the information about the photosynthetic type found for these plants can help in introducing and cultivating exotic and wild herbs and medicinal plants.

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Isotope screening is a simple and cheap test for determining the photosynthetic pathway used by plants. The scope of this work was to classify the photosynthetic type of Melissa officinalis L. and Cymbopogon citratus [DC.] Stapf, through studies of the carbon isotope composition (δ13 C), and we are proposing the use of carbon isotope composition results as a tool to control the quality of medicinal plants. For studies of δ 13C (13 C% = [R (sample)/R (standard) - 1] × 10 -3), dried, powdered leaves were analyzed in a mass spectrometer coupled with an elemental analyzer for determining the ratio R (R = 13CO2/12CO2). As results, M. officinalis presented a C3 photosynthetic type, and C. citratus presented a C4 photosynthetic type. The carbon isotope composition from this study can be used as quality control of M. officinalis adulterants.

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The concentration of total protein measured by photocolorimetric methodology and reported as units per 100 mg of tissue decreased from the initial segment to the cauda epididymidis of the Golden hamster, being significant the numeric difference observed between these two regions. This observation was related with an increased synthesis and secretion of proteins to the lumen in proximal segments of the epididymidis duct, mainly in initial segment, as proposed for other rodents. LDH activity was higher in initial segment and distal cauda than in the caput and corpus epididymidis, although no significant differences in mean values had been observed. The high LDH activity observed in initial segment and cauda epididymidis of hamster had been related to an expressive epithelium metabolic activity presented in these regions. This metabolic activity help to guarantee the survival of spermatozoa stored in cauda epididymidis. Furthermore, lower LDH activity noted in the caput and corpus epididymidis might be related with a progressive reduction of glycolysis in initial maturation step of spermatozoa mainly verified in corpus epididymidis. © 2007 Sociedad Chilena de Anatomía.

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The aim of this study was to determine the serum activities of enzymes aspartate aminotransferase, creatine kinase and lactate dehydrogenase in Arabian horses submitted to exercise on high-speed equine treadmill. Eleven mature Arabian horse were training and submitted to Standard Incremental Exercise Test on high-speed equine treadmill. Venous blood samples were taken before exercise, immediately and 30 min, 60min, 3h, 6h, 24h, 3 days and 5 days after exercise. The serum activity aspartate aminotransferase, creatine kinase and lactate dehydrogenase were determined. The serum activies of AST, CK and LDH increase immediately and returned to baseline value 30 minutes after exercise. The AST enzyme activity increased at 12 hours and 24 hours, CK at 3 hours and 6 hours, and LDH at 24 hours after Standard Incremental Exercise Test.

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Purpose: To evaluate the histological and systemic response to subcutaneous injection of polyethylene gel in rats. Methods: Twenty-one white male rats were divided into 3 groups (G): G1 and G2 received subcutaneous polyethylene gel injection in the dorsal midline and were sacrificed at 30 and 60 postoperative days, respectively. G3 was not exposed to the polyethylene gel and was sacrificed after 60 days. Blood levels of lactate dehydrogenase (LDH), creatine kinase (CK), and alkaline phosphatase (ALP) were evaluated. The heart, kidney, liver, adrenal gland, injection site, and adjacent tissues were histologically examined. The results were submitted to statistical analysis. Results: There was no clinical evidence of extrusion, reduction of the injected volume, or abnormalities in the adjacent tissues. Blood levels of CK and LDH were normal and similar in all groups. ALP levels were significantly lower in G2 than in G1 and G3. The systemic organs were normal on histological examination in the 3 groups evaluated. Microscopically, the polyethylene gel was surrounded by a thin pseudocapsule formation and minimal inflammatory cell response, which decreased from G1 to G2. Conclusion: The subcutaneous injection of polyethylene gel in rats elicited minimal local inflammatory response and no systemic side effects. Copyright © 2008 Informa Healthcare USA, Inc.

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Background. The emergence of multi- and extensively-drug resistant Mycobacterium tuberculosis strains has created an urgent need for new agents to treat tuberculosis (TB). The enzymes of shikimate pathway are attractive targets to the development of antitubercular agents because it is essential for M. tuberculosis and is absent from humans. Chorismate synthase (CS) is the seventh enzyme of this route and catalyzes the NADH- and FMN-dependent synthesis of chorismate, a precursor of aromatic amino acids, naphthoquinones, menaquinones, and mycobactins. Although the M. tuberculosis Rv2540c (aroF) sequence has been annotated to encode a chorismate synthase, there has been no report on its correct assignment and functional characterization of its protein product. Results. In the present work, we describe DNA amplification of aroF-encoded CS from M. tuberculosis (MtCS), molecular cloning, protein expression, and purification to homogeneity. N-terminal amino acid sequencing, mass spectrometry and gel filtration chromatography were employed to determine identity, subunit molecular weight and oligomeric state in solution of homogeneous recombinant MtCS. The bifunctionality of MtCS was determined by measurements of both chorismate synthase and NADH:FMN oxidoreductase activities. The flavin reductase activity was characterized, showing the existence of a complex between FMN ox and MtCS. FMNox and NADH equilibrium binding was measured. Primary deuterium, solvent and multiple kinetic isotope effects are described and suggest distinct steps for hydride and proton transfers, with the former being more rate-limiting. Conclusion. This is the first report showing that a bacterial CS is bifunctional. Primary deuterium kinetic isotope effects show that C4-proS hydrogen is being transferred during the reduction of FMNox by NADH and that hydride transfer contributes significantly to the rate-limiting step of FMN reduction reaction. Solvent kinetic isotope effects and proton inventory results indicate that proton transfer from solvent partially limits the rate of FMN reduction and that a single proton transfer gives rise to the observed solvent isotope effect. Multiple isotope effects suggest a stepwise mechanism for the reduction of FMNox. The results on enzyme kinetics described here provide evidence for the mode of action of MtCS and should thus pave the way for the rational design of antitubercular agents. © 2008 Ely et al; licensee BioMed Central Ltd.

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Type-1 diabetes patients suffer from frequent episodes of acidosis caused by an increased fatty acid metabolism and consequently increased plasma level of acetoacetate (AcAc) and β-hydroxybutyrate (β-HOB). This article describes a study of the effects of pathological concentrations of AcAc and β-HOB on lipoperoxidation, cell viability and the release of the CXCL8 (IL-8) cytokine by activated neutrophils. Neutrophils from healthy donors were isolated by density gradient (Histopaque® 1077/1119) and incubated with the ketone bodies. Lipoperoxidation was determined as thiobarbituric acid reactive substances (TBARS). The cell viability was evaluated by the release of intracellular lactate dehydrogenase. The release of CXCL8 was measured by ELISA in a 24-h culture of opsonized zymosan-stimulated neutrophils. AcAc, but not β-HOB, provoked a dose-dependent increase in the neutrophil membrane lipoperoxidation (p<0.05; r =0.9915). In the cytotoxicity assay, a dose-dependent release of LDH was observed when the neutrophils were incubated with AcAc in concentrations up to 40 mM (p<0.05). β-HOB was devoid of effect. The release of CXCL8 was inhibited by AcAc and β-HOB in a dose-dependent manner. In conclusion, these results suggest that the accumulation of ketone bodies in diabetic patients could be involved in their usually increased susceptibility to infection.

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

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This work combines symbolic machine learning and multiscale fractal techniques to generate models that characterize cellular rejection in myocardial biopsies and that can base a diagnosis support system. The models express the knowledge by the features threshold, fractal dimension, lacunarity, number of clusters, spatial percolation and percolation probability, all obtained with myocardial biopsies processing. Models were evaluated and the most significant was the one generated by the C4.5 algorithm for the features spatial percolation and number of clusters. The result is relevant and contributes to the specialized literature since it determines a standard diagnosis protocol. © 2013 Springer.

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This study was aimed to evaluate the influence of vitamin D (VD) deficiency on cardiac metabolism, morphology, and function. Thus, we investigated the relationship of these changes with the length of the nutrient restriction. Male weanling Wistar rats were allocated into 4 groups: C2 (n=24), animals were fed an AIN-93G diet with 1000 IU VD/kg of chow and were kept under fluorescent light for 2 months; D2 (n=22), animals were fed a VD-deficient AIN-93G diet and were kept under incandescent light for 2 months; C4 (n=21) animals were kept in the same conditions of C2 for 4 months; and D4 (n=23) animals were kept in the same conditions of D2 for 4 months. Biochemical analyses showed lower β-hydroxyacyl coenzyme-A dehydrogenase activity and higher lactate dehydrogenase activity in VD-deficient animals. Furthermore, VD deficiency was related to increased cytokines release, oxidative stress, apoptosis, and fibrosis. Echocardiographic data showed left ventricular hypertrophy and lower fractional shortening and ejection fraction in VD-deficient animals. Difference became evident in the lactate dehydrogenase activity, left ventricular weight, right ventricle weight, and left ventricular mass after 4 months of VD deficiency. Our data indicate that VD deficiency is associated with energetic metabolic changes, cardiac inflammation, oxidative stress, fibrosis and apoptosis, cardiac hypertrophy, left chambers alterations, and systolic dysfunction. Furthermore, length of the restriction influenced these cardiac changes.

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The aim of this study was to evaluate the effect of yacon (Smallanthus sonchifolius) (Poepp.& Endl.) on clinical parameters under diabetic conditions. The aqueous extract of yacon tuberous roots (YRAE; 0.76gfructankg-1 body weight) was prepared at the moment of each administration. Thirty-two male rats were divided into four groups (n=8): control group (C); group that received YRAE (Y); untreated diabetic group (DM1); and diabetic group treated with YRAE (Y-DM1). The diabetes mellitus was induced by streptozotocin (60mgkg-1 body weight). The animals from Y2 and Y-DM1 received YRAE by gavage, at 7-day intervals, for 30days. The aqueous extract of yacon roots decreased (p<0.05) the water and food intake in diabetic rats (Y-DM1). YRAE treatment reduced (p<0.05) glycaemia, total cholesterol, VLDL-c, LDL-c and triacylglycerol levels in diabetic rats (YRAE). HDL, urea and creatinine levels did not differ (p>0.05) between the Y and Y-DM1 groups. YRAE normalised alanine aminotransferase (ALT) activity, when comparing DM1 and Y-DM1 rats, but had no effect on lactate dehydrogenase activity (LDH). In conclusion, YRAE was sufficient for controlling water and food consumption, hyperglycaemia and dyslipidaemia, and promote the reduction of the ALT, suggesting a hepatoprotective effect in rats with STZ-induced DM1. © 2013 Elsevier Ltd.

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Preeclampsia (PE), a specific syndrome of pregnancy, can be classified into early and late onset, depending on whether clinical manifestations occur before or after 34 weeks' gestation. We determined whether plasma concentrations of Hsp60 and Hsp70 were related to circulating cytokine levels, as well as kidney and liver functions, in early- and late-onset PE. Two hundred and thirty-seven preeclamptic women (95 with early- and 142 with late-onset PE) were evaluated. Plasma levels of Hsp60, Hsp70, and their specific antibodies, tumor necrosis factor-alpha (TNF-α), interleukin (IL)-1, IL-10, IL-12, and soluble TNF-α-receptor I (sTNFRI) concentrations, were determined by enzyme-linked immunosorbent assay (ELISA). Concentrations of Hsp70, TNF-α, IL-1β, IL-12, and sTNFRI were significantly elevated in patients with early-onset PE compared with women with late-onset PE; IL-10 levels were significantly lower in the early-onset PE group. Concentrations of urea, uric acid, proteinuria, glutamic oxaloacetic transaminase (GOT), glutamic pyruvic transaminase (GPT), and lactate dehydrogenase (LDH) were also significantly higher in early-onset PE. The percentage of infants with intrauterine growth restriction was also significantly higher in women with early-onset PE. There were positive correlations between Hsp70 levels and TNF-α, TNFRI, IL-1β, IL-12, GOT, GPT, LDH, and uric acid concentrations in early-onset PE group. Thus, early-onset PE was associated with greater maternal and fetal impairment. There are differences in pathophysiology between early- and late-onset PE, highlighting by the difference in Hsp70 levels. © 2013 Elsevier B.V. All rights reserved.

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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)