1000 resultados para ddc: 001
Resumo:
The bacteriocin-producing strain Enterococcus faecium ST5Ha was isolated from smoked salmon and identified by biomolecular techniques. Ent. faecium ST5Ha produces a pediocin-like bacteriocin with activity against several lactic acid bacteria, Listeria spp. and some other human and food pathogens, and remarkably against HSV-1 virus. Bacteriocin ST5Ha was produced at high levels in MRS broth at 30 degrees C and 37 degrees C, reaching a maximum production of 1.0 x 10(9) AU/ml, checked against Listeria ivanovii ATCC19119 as target strain and surrogate of pathogenic strain Listeria monocytogenes. The molecular weight of bacteriocin ST5Ha was estimated to be 4.5 kDa according to tricine-SDS-PAGE data. Ent. faecium ST5Ha harbors a 1.044 kb chromosomal DNA fragment fitting in size to that of pediocin PA-1/AcH. In addition, the sequencing of bacteriocin ST5Ha gene indicated 99% of DNA homology to pediocin PA-1/AcH. The combined application of low levels (below MIC) of ciprofloxacin and bacteriocin ST5Ha resulted in a synergetic effect in the inhibition of target strain L ivanovii ATCC19119. Bacteriocin ST5Ha displayed antiviral activity against HSV-1, an important human pathogen, with a selectivity index of 173. To the best of our knowledge, this is the first report on Ent. faecium as a potential producer of pediocin-like bacteriocin with antiviral activity. (C) 2010 Elsevier Ltd. All rights reserved.
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Minor components (polar components) and the degree of unsaturation of the fatty acids are the main factors responsible for the oxidative stability of bulk oils and emulsions. The isolated effects of these two factors and their interaction were evaluated in oil-in-water emulsions stored at 32 A degrees C. Samples of coconut, olive, soybean, linseed and fish oils, both full and stripped of their polar components, were used to prepare the emulsions (1% w/w). The maximum concentration of hydroperoxide (LOOH(max)) and the rate of formation of hydroperoxides (mu mol L(-1) h(-1)) were used to measure the primary products. Hexanal, propanal and malondialdehyde were used to determine the secondary products of the oxidized emulsions containing polyunsaturated fatty acids. LOOH(max) varied from 0.16 to 12.75 mmol/kg among the samples. The interaction between the polar components and the degree of unsaturation of the fatty acids was significant (p < 0.001) when the hydroperoxides were evaluated. In general, the degree of unsaturation (beta(1)) and the absence of polar components (beta(2)), respectively, represented 30 and 20% of the contribution to increase the mean oxidation, with the interaction (beta(12)) contribution being more sensitive to the rate of formation of hydroperoxides (16%) than to the LOOH(max) (5%). The significance of this interaction suggests that both strategies present synergism and should be applied to improve the oxidative stability of food emulsions.
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The presence of Vibrio parahaemolyticus in 123 oyster samples collected from an estuary on the southern coast of Sao Paulo state, Brazil, was investigated. Of the 123 samples, 99.2% were positive with densities ranging from <3 to 10(5) most probable number (MPN)/g. Densities correlated significantly with water temperature (r = 0.48; P < 0.001) but not with salinity (r = -0.09; P = 0.34). The effect of harvest site on counts was not significant (P > 0.05). These data provide information for the assessment of exposure of V. parahaemolyticus in oysters at harvest.
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This study investigated the consumer attitude to food irradiation in Sao Paulo, Brazil, through a qualitative research perspective. Three focus groups were conducted with 30 consumers, responsible for food choices and purchases. Both irradiated and nonirradiated food samples were served in the sessions to motivate the discussion and elicit the participants knowledge, opinions, feelings and concerns towards the irradiation process. Reactions were similar among the groups and differences between the irradiated and the nonirradiated samples were hardly perceived. When provided with positive information about irradiation and its benefits to foods and human health, many people still remained suspicious about the safety of the technology. Risk perception seemed to be related to unease and lack of knowledge about nuclear power and its non-defense use. Participants claimed for more transparency in communication about risks and benefits of irradiated foods to the human health, especially with respect to the continued consumption. Industrial relevance: Irradiation is an emerging food processing technology, which has been gaining interest by food technologists, producers and manufacturers all over the world in the last decades. Irradiation is suitable for disinfestation, microorganism load reduction or sterilization, assuring the safety, as well as having benefits in the shelf-life of foodstuffs. Food irradiation is approved in many countries and its use in food processing is endorsed by several reputed authorities, such as FAD and USDA. Despite the approval and recommendation, this technology still remains underutilized not only in Brazil, but also in other countries. The main reason appears to be the consumer concerns and doubts about the use of radiations in food processing. To develop communication strategies in promotion of irradiated foods it is necessary to investigate consumer attitudes, knowledge. opinions, as well as fears, with respect to the use of radiation in food processing. It is well-known that consumer views on technology may vary from a culture to another. So, findings from consumer research in a country may certainly not reflect the consumer views in other countries. In this sense, Brazilian studies focused on consumer views on food irradiation are necessary to gain understanding on how the local market accepts the technology. Brazil is one of the most important food producers in the world and an emerging consumer market with a population of about 184 million people. Food irradiation is regulated in Brazil since 1973, but to date only a few food ingredients are subjected to irradiation. The wide use of irradiation in food processing would favor Brazilian producers in the quality and safety assurance of food products, both for the local market and for exports. (C) 2009 Elsevier Ltd. All rights reserved.
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Objective: Alterations in selenium (Se) status may result in suboptimal amounts of selenoproteins, which have been associated with increased oxidative stress levels. The Pro198Leu polymorphism at the glutathione peroxidase-1 (GPx1) gene is supposed to be functional. The response of Se status, GPx activity, and levels of DNA damage to a Se supplementation trial between the genotypes related to that polymorphism was investigated. Methods: A randomized trial was conducted with 37 morbidly obese women. Participants consumed one Brazil nut, which provided approximately 290 mu g of Se a day, for 8 wk. Blood Se concentrations, erythrocyte GPx activity, and DNA damage levels were measured at baseline and at 8 wk. The results were compared by genotypes. Results: The genotype frequencies were 0.487, 0.378, and 0.135 for Pro/Pro (the wild-type genotype), Pro/Leu, and Leu/Leu, respectively. At baseline, 100% of the subjects were Se deficient, and after the supplementation, there was an improvement in plasma Se (P < 0.001 for Pro/Pro and Pro/Leu, P < 0.05 for Leu/Leu), erythrocyte Se (P = 0.00 for Pro/Pro and Pro/Leu, P < 0.05 for Leu/Leu), and GPx activity (P = 0.00 for Pro/Pro, P < 0.00001 for Pro/Leu, P < 0.001 for Leu/Leu). In addition, the Pro/Pro group showed a decrease in DNA damage after Brazil nut consumption compared with baseline (P < 0.005), and those levels were higher in Leu/Leu subjects compared with those with the wild-type genotype (P < 0.05). Conclusion: Consumption of one unit of Brazil nuts daily effectively increases Se status and increases GPx activity in obese women, regardless of GPx1 Pro198Leu polymorphism. However, the evaluated biomarkers showed distinct results in response to the supplementation when the polymorphism was considered. (c) 2011 Elsevier Inc. All rights reserved.
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Whole rice contains several fat-soluble phytochemicals such. as tocopherols, tocotrienols, and gamma-oryzanol which have been reported to possess beneficial health properties. This study was conducted to determine whether brown rice belonging to indica and japonica subspecies were distinguishable from each other regarding the concentration of these compounds by analyzing 32 genotypes. The fat-soluble compounds were analyzed by normal-phase HPLC in a single run. The variability of the compounds analyzed was high, but the mean content of gamma-oryzanol across all samples was significantly higher (P < 0.01) in japonica (246.3 mg/kg) than in indica rice (190.1 mg/kg). Similar differences were found for total vitamin E contents which were 24.2 mg/kg injaponica and 17.1 mg/kg in indica rice, respectively. In japonica rice, alpha-tocopherol, alpha-tocotrienol, and gamma-tocotrienol were the most abundant homologs, while in indica rice the most abundant were gamma-tocotrienol, alpha-tocopherol, and alpha-tocotrienol. A significant Pearson coefficient (0.80, P < 0.001) between alpha-tocopherol and alpha-tocotrienol levels was found, independent of the subspecies. Both compounds were positively correlated to total tocols and gamma-oryzanol contents. Although more studies are needed to evaluate the interference of growing rice in different environments and multiple years, the present study provided information on natural variations of the vitamin E isomers and the gamma-oryzanol contents in different rice genotypes.
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Background: Chronic Kidney Disease (CKD) patients present high levels of electronegative LDL (LDL) that can modulate the expression of molecules involved in inflammation and it is closely linked to atherosclerosis. We investigated the association between LDL(-) and inflammatory markers in patients undergoing hemodialysis (HD). Methods: Forty-seven HD patients from a private clinic in Rio de Janeiro, Brazil were studied and compared with 20 age matched healthy individuals. Serum LDL(-) and anti-LDL(-) autoantibody levels were measured by ELISA; TNF-alpha, IL-6, VCAM-1 and ICAM-1 were determined by a multiplex assay kit. Results: HD patients presented higher IL-6 and TNF-alpha concentrations (4.1 +/- 1.6 and 5.5 +/- 2.1 pg/ml, respectively) than healthy subjects (2.6 +/- 0.2 and 2.4 +/- 1.1 pg/ml, respectively) (p = 0.0001). In addition, they presented higher VCAM-1 and ICAM-1 levels and, LDL(-) concentrations were also increased (0.18 +/- 0.12 U/I) when compared to healthy individuals (0.10 +/- 0.08 U/I) (p<0.02). In contrast, the anti-LDL(-) autoantibody levels were lower in HD patients (0.02 +/- 0.01 mg/l) than in healthy subjects (0.05 +/- 0.03 mg/l) (p<0.001). There was a positive correlation between LDL(-) and IL-6 (r = 0.25, p = 0.004) and ICAM-1 (r = 0.36; p = 0.003). There was also a negative correlation between anti-LDL(-) autoantibodies and TNF-alpha (r = -0.37; p = 0.003) and VCAM-1 (r = -0.50; p = 0.0001). Conclusions: The association between LDL(-) and inflammation and the lower levels of anti-LDL(-) autoantibodies are important risk factors related to atherosclerosis in CKD. (C) 2011 Published by Elsevier B.V.
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A pool of five synthetic peptides was used as an antigenic base in an ELISA (ELISA-Pp) for laboratory diagnosis of Schistosoma mansoni. Serum samples were obtained from individuals with acute (n = 23) and chronic (n = 30) schistosomiasis, with other parasitoses (n = 39) or without parasitic infections (n = 100). ELISA-Pp was compared with other immunoenzymatic methods for detection of IgM (IgM-ELISA) or IgG (IgG-ELISA) as well as an immunofluorescence test for detection of IgM antibodies (IgM-IFT). The sensitivity and specificity of ELISA-Pp was 86.8% and 94.2% when tested on the schistosomiasis group and the non-schistosomiasis group, respectively. Comparison of ELISA-Pp with other serological methods resulted in K concordance indices varying from 0.59 to 0.75. Evaluation of anti-peptide IgG antibodies showed higher Levels in patients with acute compared with chronic schistosomiasis (P = 0.001). ELISA-Pp showed satisfactory sensitivity and high specificity and may constitute a potentially useful method for laboratory diagnosis of schistosomiasis mansoni. (c) 2007 Royal Society of Tropical Medicine and Hygiene. Published by Elsevier Ltd. All rights reserved.
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Objective-Clinical trials of statins during myocardial infarction (MI) have differed in their therapeutic regimes and generated conflicting results. This study evaluated the role of the timing and potency of statin therapy on its potential mechanisms of benefit during MI. Methods and Results-ST-elevation MI patients (n = 125) were allocated into 5 groups: no statin; 20, 40, or 80 mg/day simvastatin starting at admission; or 80 mg/day simvastatin 48 hours after admission. After 7 days, all patients switched their treatment to 20 mg/day simvastatin for an additional 3 weeks and then underwent flow-mediated dilation in the brachial artery. As of the second day, C-reactive protein (CRP) differed between non-statin users (12.0 +/- 4.1 mg/L) and patients treated with 20 (8.5 +/- 4.0 mg/L), 40 (3.8 +/- 2.5 mg/L), and 80 mg/day (1.4 +/- 1.5 mg/L), and the daily differences remained significant until the seventh day (P < 0.0001). The higher the statin dose, the lower the elevation of interleukin-2 and tumor necrosis factor-alpha, the greater the reduction of 8-isoprostane and low-density lipoprotein(-), and the greater the increase in nitrate/nitrite levels during the first 5 days (P < 0.001). Later initiation of statin was less effective than its early introduction in relation to attenuation of CRP, interleukin-2, tumor necrosis factor-alpha, 8-isoprostane, and low-density lipoprotein(-), as well as in increase in nitrate/nitrite levels (P < 0.0001). At the 30th day, there was no longer a difference in lipid profile or CRP between groups; the flow-mediated dilation, however, was proportional to the initial statin dose and was higher for those who started the treatment early (P = 0.001). Conclusion-This study demonstrates that the timing and potency of statin treatment during MI are key elements for their main mechanisms of benefit.
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Objective: Our purpose was to examine the effects of daily servings of butter, no-trans-fat margarine and plant sterol margarine, within recommended amounts, on plasma lipids, apolipoproteins (Apos), biomarkers of inflammation and endothelial dysfunction, and on the transfer of lipids to HDL particles in free-living subjects with the metabolic syndrome. Methods: This was a randomized, single-blind study where 53 metabolic syndrome subjects (62% women, mean age 54 years) received isocaloric servings of butter, no-trans-fat margarine or plant sterol margarine in addition to their usual diets for 5 weeks. The main outcome measures were plasma lipids, Apo, inflammatory and endothelial dysfunction markers (CRP, IL-6, CD40L or E-selectin), small dense LDL cholesterol concentrations and in vitro radioactive lipid transfer from cholesterol-rich emulsions to HDL. Difference among groups was evaluated by analysis of variance. Results: There was a significant reduction in Apo-B (-10.4 %, P = 0.043) and in the Apo-B/Apo-A-1 ratio (-11.1%, P = 0.034) with plant sterol margarine. No changes in plasma lipids were noticed with butter and no-trans-fat margarine. Transfer rates of lipids to HDL were reduced in the no-trans-fat margarine group: triglycerides -42.0%, (P<0.001 vs butter and sterol margarine) and free cholesterol -16.2% (P = 0.006 vs sterol margarine). No significant effects were noted on the concentrations of inflammatory and endothelial dysfunction markers among the groups. Conclusions: In free-living subjects with the metabolic syndrome consumption of plant sterol and no-trans-fat margarines within recommended amounts reduced, respectively, Apo-B concentrations and the ability of HDL to accept lipids. European Journal of Clinical Nutrition (2010) 64, 1141-1149; doi:10.1038/ejcn.2010.122; published online 21 July 2010
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NUNES ALVES, M. J. N., M. R. DOS SANTOS, R. G. DIAS, C. A. AKIHO, M. C. LATERZA, M. U. P. B. RONDON, R. L. DE MORAES MOREAU, and C. E. NEGRAO. Abnormal Neurovascular Control in Anabolic Androgenic Steroids Users. Med. Sci. Sports Exerc., Vol. 42, No. 5, pp. 865-871, 2010. Purpose: Previous studies showed that anabolic androgenic steroids (AAS) increase vascular resistance and blood pressure (BP) in humans. In this study, we tested the hypotheses 1) that AAS users would have increased muscle sympathetic nerve activity (MSNA) and reduced forearm blood flow (FBF) compared with AAS nonusers and 2) that there would be an association between MSNA and 24-h BP. Methods: Twelve AAS users aged 31 +/- 2 yr (means +/- SE) and nine age-matched AAS nonusers aged 29 T 2 yr participated in the study. All individuals were involved in strength training for at least 2 yr. AAS was determined by urine test (chromatography-mass spectrometry). MSNA was directly measured by microneurography technique. FBF was measured by venous occlusion plethysmography. BP monitoring consisted of measures of BP for 24 h. Results: MSNA was significantly higher in AAS users than that in AAS nonusers (29 +/- 3 vs 20 +/- 1 bursts per minute, P = 0.01). FBF (1.92 +/- 0.17 vs 2.77 +/- 0.24 mL.min(-1).100 mL(-1), P = 0.01) and forearm vascular conductance (2.01 +/- 0.17 vs 2.86 +/- 0.31 U, P = 0.02) were significantly lower in AAS users than that in AAS nonusers. Systolic (131 +/- 4 vs 120 +/- 3 mm Hg, P = 0.001), diastolic (74 +/- 4 vs 68 +/- 3 mm Hg, P = 0.02), and mean BP (93 +/- 4 vs 86 +/- 3 mm Hg, P = 0.005) and heart rate (74 +/- 3 vs 68 +/- 3 bpm, P = 0.02) were significantly higher in AAS users when compared with AAS nonusers. Further analysis showed that there was a significant correlation between MSNA and 24-h mean BP (r = 0.75, P = 0.002). Conclusions: AAS increases MSNA and reduces muscle blood flow in young individuals. In addition, the increase in BP levels in AAS users is associated with augmented sympathetic outflow. These findings suggest that AAS increases the susceptibility for cardiovascular disease in humans.
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The aim of this study was to determine the apoptotic pathways and mechanisms involved in electronegative LDL [LDL(-)]-induced apoptosis in RAW 264.7 macrophages and the role of Nrf2 in this process. Incubation of RAW 264 7 macrophages with LDL(-) for 24 11 resulted in dose-dependent cell death. Activated caspases were shown to be involved in the apoptosis induced by LDL(-): incubation with the broad caspase inhibitor z-VAD prevented apoptosis in LDL(-)-treated cells CD95 (Fas), CD95 ligand (FasL). CD36 and the tumor necrosis factor (TNF) ligand Tnfsf10 were overexpressed in LDL(-)-treated cells However, Bax, Bcl-2 and Mcl-1 protein levels remained unchanged after LDL(-) treatment. LDL(-) promoted hyperpolarization of the mitochondrial membrane, elevated reactive oxygen species (ROS) production and translocation of Nrf2 to the nucleus, a process absent in cells treated with native LDL Elicited peritoneal macrophages from Nrf2-deficient mice exhibited an elevated apoptotic response after challenge with LDL(-), together with an increase in the production of ROS in the absence of alterations in CD36 expression These results provide evidence that CD36 expression induced by LDL(-) is Nrf2-dependent. Also, it was demonstrated that Nrf2 acts as a compensatory mechanism of LDL(-)-induced apoptosis in macrophages. (C) 2009 Elsevier B V. All rights reserved
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Background: Coadministration of any statin with ezetimibe is as effective as using high doses of the same statin in the reduction Of tow-density lipoprotein cholesterol (LDL-c). There may be other effects called pleiotropics. Objective: To compare the effectiveness of 2 different treatments that obtain equivalent LDL-c reductions (80 mg of simvastatin, once a clay and coadministration of 10 mg of simvastatin and 10 mg of ezetimibe, once a day) over endothelial function and inflammation. Methods: Twenty-three randomized patients with hypercholesterolemia in a 2 X 2 crossover protocol were Studied. Endothelial function was analyzed by ultrasound assessment of endothelial dependent flow-mediated vasodilation of the brachial artery, and inflammation was estimated by high-sensitivity C-reactive protein (hs-CRP). Results: LDL-c reduction was similar between the 2 treatments with simvastatin/ezetimibe and with simvastatin (P < 0.001); no difference between treatments was found (P = 0.968). Both treatments improved significantly the endothelial function [3.61% with simvastatin/ezetimibe (P = 0.003) and 5.08%. with simvastatin (P < 0.001)]; no difference was found between the 2 treatments (P = 0.291). hs-CRP had a 23% reduction with simvastatin/ezetimibe (P = 0.004) and a 30% reduction with simvastatin alone (P = 0.01), with no significant difference between the 2 treatments (P = 0.380). Conclusion: The 2 forms of treatment presented similar pleiotropic effects: improvement in endothelial function and decrease in hsCRP levels.
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Objectives: To evaluate biomarkers of endothelial dysfunction and oxidative stress in glucose intolerance (GI) compared to overt diabetes (DM2). Design and methods: 140 volunteers including 96 with DM2, 32 with GI and 12 controls (C) were Studied. NO metabolites, NO synthase inhibitors. thiols and N-acetyl-beta-glucosaminidase (NAGase) activity were analyzed by chemiluminescence, capillary electrophoresis, ELISA and colorimetric assay, respectively. Results: (center dot)NO metabolites were higher in GI (NOx: P=0.03 S-nitrosothiols: p=0.001) and DM2 (p=0.006; p=0.0006) groups in relation to group C, while nitrotyrosine was higher only in the DM2 group in comparison 10 the other groups. NAGase activity was elevated in GI (p=0.003) and DM2 (p=0.0004) groups in relation to group C, as well as, ADMA (p=0.01: p=0.003) and GSSG (p=0.01 p=0.002). Conclusions: (center dot)NO metabolites. (center dot)NO synthase inhibitors. thiols and NAGase are biomarkers Suitable to indicate endothelial dysfunction and oxidative stress in the early stages of impaired response to insulin. (c) 2008 The Canadian Society of Clinical Chemists. Published by Elsevier Inc. All rights reserved.
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The aim of this Study was to determine if protein-energy malnutrition Could affect the hematologic response to granulocyte colony-stimulating factor (G-CSF). Swiss mice were fled a low-protein diet containing 4% protein, whereas control mice were fed a 20% protein-containing diet. After the malnourished group lost 20% of their original body weight, the mice were subdivided in 2 treatment groups, and hematopoietic parameters were studied. Mice were injected with either 8 mu g/kg per day of G-CSF or saline twice daily for 4 days. Malnourished mice developed anemia with reticulopenia and leukopenia with depletion of granulocytes and lymphocytes. Both malnourished and control mice treated with G-CSF showed a significant increase in neutrophils; however, in the control group, this increase was more pronounced compared to the malnourished group (4.5-fold and 3.4-fold, respectively). Granulocyte colony-stimulating factor administration increased bone marrow blastic (P < .001) and granulocytic (P < .01) compartments in the controls bill had no significant effect oil these hematopoietic compartments in the Malnourished animals (P = .08 and P = .62, respectively). We report that malnourished mice display an impaired response to G-CSF, which contributes to the decreased production of leukocytes in protein-energy malnutrition. (C) 2008 Elsevier Inc. All rights reserved.