902 resultados para Glycolytic pathway and tricarboxylic acid cycle


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It has been reported that mental stress causes abnormality of spermiogram parameters. We investigated the effect of psychological stress on the L-arginine-nitric oxide (NO) pathway. Semen samples were collected from 29 healthy fourth semester medical students just before (stress) and 3 months after (non-stress) the final examinations. Psychological stress was measured by the State Anxiety Inventory questionnaire. After standard semen analysis, arginase activity and NO concentration were measured spectrophotometrically in the seminal plasma. Measurements were made in duplicate. During the stress period, sperm concentration (41.28 ± 3.70 vs 77.62 ± 7.13 x 10(6)/mL), rapid progressive motility of spermatozoa (8.79 ± 1.66 vs 20.86 ± 1.63%) and seminal plasma arginase activity (0.12 ± 0.01 vs 0.22 ± 0.01 U/mL) were significantly lower than in the non-stress situation, whereas seminal plasma NO (17.28 ± 0.56 vs 10.02 ± 0.49 µmol/L) was higher compared to the non-stress period (P < 0.001 for all). During stress there was a negative correlation between NO concentration and sperm concentration, the percentage of rapid progressive motility and arginase activity (r = -0.622, P < 0.01; r = -0.425, P < 0.05 and r = -0.445, P < 0.05, respectively). These results indicate that psychological stress causes an increase of NO level and a decrease of arginase activity in the L-arginine-NO pathway. Furthermore, poor sperm quality may be due to excessive production of NO under psychological stress. In the light of these results, we suggest that the arginine-NO pathway, together with arginase and NO synthase, are involved in semen quality under stress conditions.

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The aim of the present study was to evaluate the relationship between salivary oxidative stress and dental-oral health. Healthy young adults, matched for gender and age, with (N = 21, 10 men, mean age: 20.3 ± 1 years) and without (N = 16, 8 men, mean age: 21.2 ± 1.8 years) caries were included in this study. The World Health Organization (WHO) caries diagnostic criteria were used for determining the decayed, missing, filled teeth (DMFT) index. The oral hygiene and gingival status were assessed using the simplified oral hygiene index and gingival index, respectively. Unstimulated salivary total protein, glutathione (GSH), lipid peroxidation and total sialic acid levels, carbonic anhydrase activity, and salivary buffering capacity were determined by standard methods. Furthermore, salivary pH was measured with pH paper and salivary flow rate was calculated. Simplified oral hygiene index and gingival index were not significantly different between groups but DMFT scores were significant (P < 0.01). Only, GSH values were significantly different (P < 0.05) between groups (2.2 and 1.6 mg/g protein in young adults without caries and with caries, respectively). There was a significant negative correlation between DMFT and GSH (r = -0.391; P < 0.05; Pearson's correlation coefficient). Our results suggest that there is an association between caries history and salivary GSH levels.

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Evaluating the activity of the complement system under conditions of altered thyroid hormone levels might help elucidate the role of complement in triggering autoimmune processes. Here, we investigated alternative pathway (AP) activity in male Wistar rats (180 ± 10 g) after altering their thyroid hormone levels by treatment with triiodothyronine (T3), propylthiouracil (PTU) or thyroidectomy. T3 and thyroxine (T4) levels were determined by chemiluminescence assays. Hemolytic assays were performed to evaluate the lytic activity of the AP. Factor B activity was evaluated using factor B-deficient serum. An anti-human factor B antibody was used to measure factor B levels in serum by radial immunodiffusion. T3 measurements in thyroidectomized animals or animals treated with PTU demonstrated a significant reduction in hormone levels compared to control. The results showed a reduction in AP lytic activity in rats treated with increasing amounts of T3 (1, 10, or 50 µg). Factor B activity was also decreased in the sera of hyperthyroid rats treated with 1 to 50 µg T3. Additionally, treating rats with 25 µg T3 significantly increased factor B levels in their sera (P < 0.01). In contrast, increased factor B concentration and activity (32%) were observed in hypothyroid rats. We conclude that alterations in thyroid hormone levels affect the activity of the AP and factor B, which may in turn affect the roles of AP and factor B in antibody production.

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Fractionation of the EtOH extract from aerial parts of Baccharis uncinella C. DC. (Asteraceae) led to isolation of caffeic and ferulic acids, which were identified from spectroscopic and spectrometric evidence. These compounds exhibit antioxidant and anti-inflammatory properties and have been shown to be effective in the prevention/treatment of metabolic syndrome. This study investigated whether the combined treatment of caffeic and ferulic acids exhibits a more significant beneficial effect in a mouse model with metabolic syndrome. The combination treatment with caffeic and ferulic acids was tested for 60 days in C57 mice kept on a high-fat (40%) diet. The data obtained indicated that treatment with caffeic and ferulic acids prevented gain in body weight induced by the high-fat diet and improved hyperglycemia, hypercholesterolemia and hypertriglyceridemia. The expression of a number of metabolically relevant genes was affected in the liver of these animals, showing that caffeic and ferulic acid treatment results in increased cholesterol uptake and reduced hepatic triglyceride synthesis in the liver, which is a likely explanation for the prevention of hepatic steatosis. In conclusion, the combined treatment of caffeic and ferulic acids displayed major positive effects towards prevention of multiple aspects of the metabolic syndrome and liver steatosis in an obese mouse model.

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Changes in the profile of volatile compounds after the heating of refined soybean oil without adding antioxidants, and treated with quercetin and chlorogenic acid (5-CQA) were investigated by GC/FID, GC/MS, and GC/SNIFFING. The heating temperature of the oil sample was 20 °C for the first minute, and then it was increased up to 160 °C at the rate of 10 °C min-1. The final temperature was kept for 10 minutes. 19 volatiles were identified in the heated samples without antioxidants. Medium-chain carbonyls predominated in the volatile fraction, mainly 2-heptenal, 2,4-heptadienal and 2,4-decadienal. Around 11 to 15 volatile compounds were detected in the heated samples treated with 5-CQA and quercetin, respectively. 5-CQA was not very efficient in delaying the formation of oxidative volatile compounds. The samples quercetin presented lower proportion of carbonyls with C6-C9.. The GC peak area data were used as an approach to estimate the relative content of each volatile compound and indicate that the samples treated with quercetin (p < 0.05) had significantly lower values for, 1-pentanol, 2,4-heptadienal, and 2,4-decadienal compared with those without antioxidants and treated with 5-CQA. GC/SNIFFING analysis revealed a smaller odor perception in the samples treated with 5-CQA compared to those without antioxidants. No odor was perceived in the heated samples treated with quercetin. These results indicate greater effectiveness of quercetin in delaying the formation of oxidative volatile compounds in soybean oils subjected to mild heating conditions. Apparently, biopolyphenols used in the present work showed good oxidative stability since no new volatile compound was detected in the heated samples treated with them.

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This study aimed to evaluate the antioxidant potential and fatty acid profile of gabiroba (Campomanesia xanthocarpa Berg) seeds. In order to obtain the extract, the seeds were dried, crushed, and subjected to sequential extraction by maceration and percolation in a modified soxhlet extractor using solvent polarity gradient composed of hexane, chloroform, ethyl acetate, and alcohol, respectively. The extraction time was six hours. The ethanol extract showed the highest antioxidant potential, given by the EC50 value and the amount of total phenolic compounds. High amounts of unsaturated fatty acids were found in the oil studied, especially the oleic acid.

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The aim of this study was to determine the nutritional composition (moisture, protein, carbohydrates, and total fat) of some meat products produced in the northeastern Argentina, analyzing fatty acids composition, polyunsaturated/saturated fatty acid ratio PUFA/SFA ratio (polyunsaturated/ saturated fatty acids), n-6/n-3 ratio, and CLA (conjugated linoleic acid) content. Thirty traditional meat products produced by different processes were used. The samples were classified into 4 different categories as follows: salamín (dry cured and fermented sausage), chorizos (raw sausage), chorizo ahumado (cooked and smoked sausage), and morcilla (cooked sausage). From the results obtained it can be said that the total carbohydrate contents of the salamín studied were slightly lower; fat content of raw chorizo was significantly lower, and protein content of chorizo ahumado was significantly higher than those comparison from databases from other regions of Argentina, USA, and Spain. Except for chorizo, which has a value lower than 0.4, the PUFA/SFA-stearic ratio of the other products were a little higher than those reported by other researchers. CLA (Conjugated linoleic acid) contents between 0.03% and 0.19% were detected. The results obtained indicate that salamín produced in northeastern Argentina, Chaco state, shows high protein and PUFA (Polyunsaturated fatty acids) contents, and low atherogenic and thrombogenic indexes, which makes it a more healthful product than those of similar composition produced in other countries.

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Mallow leaves (Malva sylvestris L.) with initial moisture of 5.02±0.003 on dry basis (82.5% on wet basis) were dried using three different drying methods, microwave, convective and vacuum. The leaves that weigh 75 g each were dried until their moisture fell down to 0.10±0.005 on dry basis (approximately 9% on wet basis). The following drying levels were used in each of the drying processes: 6.67, 8.67, 10, 11.33 W g-1 microwave power density; 50, 75, 100 and 125 °C for convective drying; and 3, 7 kPa at 50 and 75 °C for vacuum drying. Drying periods ranged from 6-10, 26-150 and 38-130 min. for microwave, convective and vacuum drying, respectively. Effective moisture diffisuvities ranged from 2.04403 10-10-3.63996 10-12 m2 s-1, 1.70182 10-11-1.10084 10-10 m2 s-1 and 1.85599 10-11-5.94559 10-10 m2 s-1 for microwave, convective and vacuum drying, respectively. According to ascorbic acid content and color parameters, the best microwave power density was found 10 W g-1 with a drying period of 6.5 min.

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Abstract In this study, our aim was to consider the production of fish crackers using Carassius gibelio and to investigate the fatty acid profile and sensory quality of the fish crackers. Fish cracker mixture with a ratio 3.5:1.5 (minced fish/wheat starch) was obtained. Based on the total minced fish and starch level, 1.75% salt, 0.25% black pepper, 2% sunflower oil, 1% baking powder and 10% cold water (4 °C) were added and stirred until a homogenous mixture was obtained. The mixture was compressed in an extractor and baked. The moisture content of minced fish (CMF), cracker dough (CD) and crackers (CCr) was 77.73 ± 0.14%, 63.10 ± 2.18% and 7.95 ± 0.67% respectively. The n6/n3 ratio of crackers was 2.61 ± 0.20, PUFA/SFA ratio 2.28 ± 0.06 and DHA/EPA ratio 1.81 ± 0.01. The overall acceptability score obtained by the sensory evaluation of panelists was very high (8.09 ± 0.25).

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Humic substances are complex polymeric structures.No other polymers with such a wide range of properties are so widely distributed in nature.But still their moleculer structures are unknown. A structural knowledge is essential in determining their reactivity with metals.In the present work structural elucidation of humic acids from three different mangrove ecosystems of Cochin area is done with the available data from functional group analysis and various spectroscopic methods.13C NMR spectra of the solid samples with CPMAS,IR and SEM are very promising in revealing the complex structures of these polymeric substances.Sorptional studies on the sediment and humic acid of mangrove ecosystem reveals that the major portion of the organic matter is not extractable with Sodium hydroxide and humic acid only a small portion of the total organic matter. Humic acid is a good complexing agent and scavenger. Due to the nonextractable nature of the organic matter present with the sediment left after alkali extraction it is a better scavenger.

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Organic crystals possess extremely large optical nonlinearity compared to inorganic crystals. Also organic compounds have the amenability for synthesis and scope for introducing desirable characteristics by inclusions. A wide variety of organic materials having electron donor and acceptor groups, generate high order of nonlinearity. In the present work, a new nonlinear optical crystal, L-citrulline oxalate (LCO) based on the aminoacid L-citrulline was grown using slow evaporation technique. Structural characterization was carried out by single crystal XRD. It crystallizes in the noncentrosymmetric, orthorhombic structure with space group P21 P21 P21. Functional groups present in the sample were identified by Fourier transform infra red (FTIR) and FT-Raman spectral analysis. On studying the FTIR and Raman spectra of the precursors L-citrulline and oxalic acid, used for growing L-citrulline oxalate crystal, it is found that the significant peaks of the precursors are present in the spectra of the L-citrulline oxalate crystal . This observation along with the presence of NH3 + group in the spectra of L-citrulline oxalate, confirms the formation of the charge transfer complex

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Over the past years there has been considerable interest in the growth of single crystals both from the point of view of basic research and technological application. With the revolutionary emergence of solid state electronics which is based on single crystal technolo8Ys basic and applied studies on crystal growth and characterization _have gained a-more significant role in material science. These studies are being carried out for single crystals not only of semiconductor and other electronic materials but also of metals and insulators. Many organic crystals belonging to the orthorhombic class exhibit ferroelectric, electrooptic, triboluminescent and piezoelectric properties. Diammonium Hydrogen Citrate (DAHC) crystals are reported to be piezoelectric and triboluminescent /1/. Koptsik et al. /2/ have reported the piezoelectric nature of Citric Acid Monohydrate (CA) crystals. And since not much work has been done on these crystals, it has been thought useful to grow and characterize these crystals. This thesis presents a study of the growth of these crystals from solution and their defect structures. The results of the microindentation and thermal analysis are presented. Dielectric, fractographic, infrared (IR) and ultraviolet (UV) studies of DAHC crystals are also reported

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Marine Aspergillus awamori BTMFW032, recently reported by us, produce acidophilic tannase as extracellular enzyme. Here, we report the application of this enzyme for synthesis of propyl gallate by direct transesterification of tannic acid and in tea cream solubilisation besides the simultaneous production of gallic acid along with tannase under submerged fermentation by this fungus. This acidophilic tannase enabled synthesis of propyl gallate by direct transesterification of tannic acid using propanol as organic reaction media under low water conditions. The identity of the product was confirmed with thin layer chromatography and Fourier transform infrared spectroscopy. It was noted that 699 U/ml of enzyme could give 60% solubilisation of tea cream within 1 h. Enzyme production medium was optimized adopting Box–Behnken design for simultaneous synthesis of tannase and gallic acid. Process variables including tannic acid, sodium chloride, ferrous sulphate, dipotassium hydrogen phosphate, incubation period and agitation were recognized as the critical factors that influenced tannase and gallic acid production. The model obtained predicted 4,824.61 U/ml of tannase and 136.206 μg/ml gallic acid after 48 h of incubation, whereas optimized medium supported 5,085 U/ml tannase and 372.6 μg/ml of gallic acid production after 36 and 84 h of incubation, respectively, with a 15-fold increase in both enzyme and gallic acid production. Results indicated scope for utilization of this acidophilic tannase for transesterification of tannic acid into propyl gallate, tea cream solubilisation and simultaneous production of gallic acid along with tannase