892 resultados para Selenium Supplementation


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It currently is unknown whether creatine supplementation is safe for people with or at risk of kidney disease. We report on the short-term effects of creatine supplementation on kidney function in a young man with a single kidney and mildly decreased glomerular filtration rate (GFR). A 20-year-old man who had undergone unilateral nephrectomy and presented with mildly decreased GFR without kidney damage underwent a trial with 35 days of creatine supplementation (20 g/d for 5 days followed by 5 g/d for the next 30 days) and had his kidney function monitored. After the intervention, (51)Cr-EDTA clearance (pre, 81.6 mL/min/1.73 m(2); post, 82.0 mL/min/1.73 m(2)), proteinuria (protein excretion: pre, 130 mg/d; post, 120 mg/d), and electrolyte levels were unchanged. Albuminuria, serum urea level, and estimated creatinine clearance were decreased (pre, 4.6 mg/d; post, 2.9 mg/d; pre, 37 mg/d; post, 28 mg/dL; and pre, 88 mL/min/1.73 m(2); post, 71 mL/min/1.73 m(2), respectively), whereas serum creatinine level was slightly increased (pre, 1.03 mg/dL; post, 1.27 mg/dL), falsely suggesting kidney function impairment. This prospective report suggests that short-term creatine supplementation may not affect kidney function in an individual with a single kidney, mild decreased GFR, and ingesting a high-protein diet (ie, 2.8 g/kg/d). This finding has great relevance considering that creatine-induced kidney disease has been a growing concern, even for healthy people. Am J Kidney Dis 55: e7-e9. (C) 2010 by the National Kidney Foundation, Inc.

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Milk supplementation with milk proteins in four different levels was used to investigate the effect on acidification and textural properties of yogurt. Commercial skim milk powder was diluted in distilled water, and the supplements were added to give different enriched-milk bases; these were heat treated at 90 degrees C for 5 min. These mixtures were incubated with the bacterial cultures for fermentation in a water bath, at 42 degrees C, until pH 4.50 was reached. Chemical changes during fermentation were followed by measuring the pH. Protein concentration measurements, microbial counts of Lactobacillus bulgaricus and Streptococcus thermophilus, and textural properties (G`, G ``, yield stress and firmness) were determined after 24 h of storage at 4 degrees C. Yogurt made with milk supplemented with sodium caseinate resulted in significant properties changes, which were decrease in fermentation time, and increase in yield stress, storage modulus, and firmness, with increases in supplement level. Microstructure also differed from that of yogurt produced with milk supplemented with skim milk powder or sodium caseinate. (C) 2009 Elsevier Ltd. All rights reserved.

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An efficient method for chemoenzymatic dynamic kinetic resolution of selenium-containing chiral amines (organoselenium-1-phenylethanamines) has been developed, leading to the corresponding amides in excellent enantioselectivities and high isolated yields. This one-pot procedure employs two different types of catalysts: Pd on barium sulphate (Pd/BaSO(4)) as racemization catalyst and lipase (CAL-B) as the resolution catalyst. (C) 2009 Elsevier Ltd. All rights reserved.

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In this study we examined the possible antigenotoxic effect of selenium (Se) in rats chronically exposed to low levels of methylmercury (MeHg) and the association between glutathione peroxidase (GSH-Px) activity and DNA lesions (via comet assay) in the same exposed animals. Rats were divided into six groups as follows: (Group I) received water; (Group II) received MeHg (100 mu g/day); (Group III) received Se (2 mg/L drinking water); (Group IV) received Se (6 mg/L drinking water); (Group V) received MeHg (100 mu g/day) and Se (2 mg/L drinking water); (Group VI) received MeHg (100 mu g/day) and Se (6 mg/L drinking water). Total treatment time was 100 days. GSH-Px activity was determined spectrophotometrically and DNA damage was determined by comet assay. Mean GSH-Px activity in groups I, II, III, IV, V and VI were, respectively: 40.19 +/- A 17.21; 23.63 +/- A 6.04; 42.64 +/- A 5.70; 38.50 +/- A 7.15; 34.54 +/- A 6.18 and 41.39 +/- A 11.67 nmolNADPH/min/gHb. DNA damage was represented by a mean score from 0 to 300; the results for groups I, II, III, IV, V and VI were, respectively: 6.87 +/- A 3.27; 124.12 +/- A 13.74; 10.62 +/- A 3.81; 13.25 +/- A 1.76; 86.87 +/- A 11.95 and 76.25 +/- A 7.48. There was a significant inhibition of GSH-Px activity in group II compared with group I (P < 0.05). Groups V and VI did not show a difference in enzyme activity compared with groups III and IV, showing the possible protective action of Se. Comet assay presented a significant difference in DNA migration between group II and group I (P < 0.0001). Groups V and VI showed a significant reduction in MeHg-induced genotoxicity (P < 0.001) when compared with group II. A negative correlation (r = -0.559, P < 0.05) was found between GSH-Px activity and DNA lesion, showing that the greater the DNA damage, the lower the GSH-Px activity. Our findings demonstrated the oxidative and genotoxic properties of MeHg, even at low doses. Moreover, Se co-administration reestablished GSH-Px activity and reduced DNA damage.

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The deposition and characterization of Se films doped with Pb underpotentially deposited (UPD) ad-atoms was studied in this work. The employed experimental techniques were cyclic voltammetry, chronoamperometry, electrochemical impedance spectroscopy, UV-vis spectroscopy and atomic force microscopy. The initial deposition of Se film by chronoamperometry yielded a thin film composed of approximately 700 layers. The Pb UPD on Se was achieved by chronoamperometry in a potential value previously determined in voltammetric experiments. This deposition yielded a deposition charge of approximately 7.5% of the total one. The film resistance altered from 320 Omega cm(2) for Se to 65 Omega cm(2) for the Se/Pb one. Flat band potential values and number of acceptors and donors were also calculated for both films and the values obtained were + 0.95 and -0.51 V for Se and Se/Pb, respectively. The Se coating presented 1.2 x 10(17) cm(3) acceptors while the Se/Pb one presented 3.2 x 10(17) cm(3) donors. The band gap values for both films were 2.4 eV and 1.9 eV, correspondingly. (C) 2008 Elsevier B.V. All rights reserved.

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In this paper we report here new considerations about the relationship between the mass and charge variations (m/z relationship) in underpotential deposition (UPD), bulk deposition and also in the H(2)Se formation reaction. Nanogravimetric experiments were able to show the adsorption of H(2)SeO(3) on the AuO surface prior to the voltammetric sweep and that, after the AuO reduction, 0.40 monolayer of H(2)SeO(3) remains adsorbed on the newly reduced Au surface, which was enough to gives rise to the UPD layer. The UPD results indicate that the maximum coverage with Se(ads) on polycrystalline gold surface corresponds to approximately 0.40 monolayer, in good agreement with charge density results. The cyclic voltammetry experiments demonstrated that the amount of bulk Se obtained during the potential scan to approximately 2 Se monolayers, which was further confirmed by electrochemical quartz crystal microbalance (EQCM) measurements that pointed out a mass variation corresponding of 3 monolayers of Se. In addition, the Se thin films were obtained by chronoamperometric experiments, where the Au electrode was polarized at +0.10V during different times in 1.0 M H(2)SO(4) + 1.0 mM SeO(2). The topologic aspects of the electrodeposits were observed in Atomic Force Microscope (AFM) measurements. Finally, in highly negative potential polarizations, the H(2)Se formation was analyzed by voltammetric and nanogravimetric measurements. These finding brings a new light on the selenium electrodeposition and point up to a proposed electrochemical model for molecule controlled surface engineering. (c) 2009 Elsevier Ltd. All rights reserved.

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A participação no comércio internacional passou a ser indispensável para a sobrevivência das empresas. A necessidade de disponibilizar produtos com qualidade e competitividade em novos mercados faz com que as organizações utilizem todos os recursos da logística internacional. Neste contexto, com a criação de Centros de Distribuições internacionais, as empresas terão a possibilidade de incrementar suas vendas e satisfazer seus clientes. Através de uma revisão bibliográfica de temas como logística, armazenagem, distribuição e marketing, este trabalho tem como objetivo determinar quais as variáveis que intervém no sucesso ou no fracasso da internacionalização das empresas, quando da implantação de um Centro de Distribuição no exterior. Este estudo analisa o caso da Eletrônica Selenium, que iniciou seu processo de internacionalização através da criação de um Centro de Distribuição na costa leste do Estados Unidos da América. A implantação de um novo Centro de Distribuição, na costa oeste americana, é fundamental para a continuação do sucesso de internacionalização da empresa. Este processo está trazendo resultados positivos para a empresa, como maior agilidade para atender à demanda, aumento de seus lucros e da participação no mercado, compensando os custos relativos a esta operação, podendo-se já observar um aumento no volume de vendas de aproximadamente 50%, bem como uma redução no prazo de reabastecimento dos clientes de seis para três dias.

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Arginine was hypothesized to be a model compound in the present study on molecular forms of indispensable amino acid (IAA) dietary supplementation. Juvenile South American pacu (Piaractus mesopotamicus) were fed diets containing arginine in a protein base (casein-wheat gluten or casein-gelatin), or the casein-wheat gluten base supplemented with dipeptide or free arginine at two levels (5 and 10 g kg(-1)). Growth and protein efficiency ratios were significantly affected by diets, but not by arginine molecular form. Three free dispensable amino acids (DAA) and four IAA in plasma were affected by diet, but plasma arginine concentrations did not differ. Plasma urea concentrations, being very low in the pacu, and hepatic arginase activities, were not affected by diet (P = 0.10-0.11), but together with plasma ornithine, mirrored the growth data. Molecular form of arginine supplementation, free or dipeptide, significantly changed several free IAA (Phe, Leu, Ile, His) and urea, with a higher mean plasma concentration in dipeptide fed fish. The dietary treatments, or molecular form of the arginine supplementation, did not change proximate composition, except that calcium levels decreased with higher dietary arginine supplementation level. The present study indicates that dipeptides can provide IAA to pacu, and that arginine supplemented in this form is utilized as efficiently as in free form.

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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

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Freshwater fish are an important source of protein, but they also contain other highly nutritive components such as fats. Polyunsaturated fatty acids (PUFAs) are essential for normal growth, development and reproduction of vertebrates. The antioxidant role of vitamin E in cell membranes prevents fatty acid and cholesterol oxidation, thereby promoting PUFA and subcellular particle stabilization. The effects of vitamin E supplementation on the quality of Nile tilapia (Oreochromis niloticus) carcass were investigated. The experiments were carried out in an experimental laboratory over 106 d. After sex reversal, 400 early juvenile O. niloticus were tested in a completely randomized experiment with 5 treatments (4 repetitions each), consisting of vitamin E monophosphate supplementation at 0, 50, 100, 150 or 200 mg/kg of a base diet. Treatment diets contained equal amounts of protein and energy. Tilapias supplemented with vitamin E contained arachidonic acid (20:4 omega-6; AA) which participates in inflammatory response. Nile tilapia carcasses that received vitamin E at 100 and 150 mg/kg diet had improved carcass quality by increasing the PUFA:SFA ratio and had the highest levels of polyunsaturated fatty acids from the omega-3 (linolenic acid; 18:3 omega-3) and omega-6 (linoleic acid; 18:2 omega-6) series. (C) 2012 Elsevier Ltd. All rights reserved.

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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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Six hundred and forty one-day-old Cobb male broilers were used to evaluate ornithine decarboxylase (ODC) expression in the mucosa of the small intestine. Birds were submitted to early feed restriction from 7 to 14 days of age. The provided feed was supplemented with glutamine. A completely randomized design with a 2 x 2 factorial arrangement was used (with or without glutamine, with or without feed restriction). Restricted-fed birds were fed at 30% the amount of the ad libitum fed group from 7 to 14 days of age. Glutamine was added at the level of 1% in the diet supplied from 1 to 28 days of age. Protein concentration in the small intestine mucosa was determined, and ODC expression at 7, 14, 21, and 28 days of age was evaluated by dot blotting. ODC was present in the mucosa of broilers, and the presence of glutamine in the diet increased ODC activation. Glutamine prevented mucosa atrophy by stimulating protein synthesis, and was effective against the effects of feed restriction. Dot blotting can be used to quantify ODC expression in the intestinal mucosa of broilers.

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This study was carried out to verify if Saccharomyces cerevisiae cell wall (SCCW) dietary supplementation (0.2%) was capable of protecting the intestinal mucosa of broiler chickens vaccinated against coccidiosis. Body weight gain, feed intake, feed conversion and intestinal mucosa morphometric parameters and epithelial loss were evaluated. In the experiment,400 day-old male chicks were distributed according to a completely randomized design in a 2x2 factorial arrangement. The following treatments were applied: T1 - no vaccination/ no SCCW supplementation; T2 - no vaccination/SCCW supplementation; T3 - vaccination/no SCCW supplementation; and T4 - vaccination/SCCW supplementation to four replicates of 25 birds each. Birds were vaccinated on the first day of age using a spray vaccine (Coccivac B®, Coopers), containing E. acervulina, E. maxima, E. mivati and E. tenella. S. cerevisiae cell wall was supplied from the first day of age. Live performance, intestinal morphometric parameters and epithelial loss were evaluated at 14, 21 and 28 days of age. Performance was affected by vaccination only at 21-days of age, when body weight gain was reduced in the vaccinated birds, but no body weight difference was observed on day 28. Vaccine also increased the crypt depth (p<0.05) in the duodenum and jejunum, suggesting a high cell activity in the crypt:villus transition area to maintain the epithelial cell turnover. Villi number/area (103,269 µm²) was not affected (p>0.05) by vaccine or cell wall supplementation, and epithelial loss was more pronounced in the duodenum and jejunum. In conclusion, the findings of this study suggest that S. cerevisiae cell wall supplementation may be an useful management tool to maintain the intestinal integrity of broilers vaccinated against coccidiosis.

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The present study was carried out with the objective of evaluating the effects of feeding dairy cows with organic or inorganic sources of zinc (Zn), copper (Cu) and selenium (Se) on blood concentrations of these minerals, blood metabolic profiles, nutrient intake and milk yield and composition. Nineteen Holstein cows were selected and randomly assigned to two groups for receiving organic (n = 9) or inorganic (n = 10) sources of Zn, Cu and Se from 60 days before the expected date of calving to 80 days of lactation. Samples of feed, orts and milk were collected for analysis. Body condition score (BCS) was determined and blood samples were collected for analysis of Zn, Cu and Se concentrations, as well as for metabolic profile. Supplying organic or inorganic sources of Zn, Cu, and Se did not affect dry matter and nutrient intake, blood metabolic profile, milk yield and composition, plasma concentration of these minerals, and BCS or change the BCS in cows from 60 days before the expected date of calving to 80 days of lactation. An effect of time was observed on all feed intake variables, plasma concentrations of Zn and Se, milk yield, milk protein content, BCS and change in BCS.