814 resultados para Vitamin D Assay


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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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O experimento foi conduzido em câmara climática para determinar os efeitos das vitaminas D3 e C sobre o desempenho, temperatura corporal e qualidade dos ovos de poedeiras em três temperaturas: termoneutra (24,8º a 27,0º C), estresse calórico cíclico (26,2º C por 16h e 32,1º C por 8h) e estresse calórico constante (30,0º a 32,0º C). Foram utilizadas 144 galinhas brancas com 31 semanas num delineamento inteiramente ao acaso em arranjo fatorial 3x3x3: vitamina D3 (2500, 3000 e 3500 UI/kg), vitamina C (0, 200 e 400 ppm) e temperatura ambiente (termoneutra, estresse calórico cíclico e constante). As características avaliadas foram: consumo de ração (CR), produção de ovos (PO), peso dos ovos (PE), massa de ovos (MO), conversão alimentar (CA), porcentagens de albúmem (AL) e de gema (GE), unidade Haugh (UH), índice de gema (IG), porcentagem de casca (PC), espessura de casca (EC), gravidade específica dos ovos (GO), temperaturas dorsal (TD) e retal (TR). A vitamina D3 interferiu nas características PC, EC, GO e TD; a vitamina C no IG, PC e GO. A temperatura ambiente não afetou somente a UH. Concluiu-se que níveis mais altos de vitamina D3 e níveis de 200 ou 400 ppm de vitamina C na dieta podem melhorar a qualidade da casca e que o estresse calórico prejudicou as principais características avaliadas.

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Introduction: In this report, we propose the application of the p-iodophenol-enhanced luminol chemiluminescent technique to the determination of peroxidase (myeloperoxidase and/or platelet peroxidase) activity in blasts of minimally differentiated acute myeloblastic leukemia (AML-M0) and acute megakaryoblastic leukemia (AML-M7).Methods: the frozen blast cells from 29 patients were thawed and submitted to the optimized protocol.Results: All cases of AML-M7 and AML-M0 exhibited integrated light emission greater than 73 (10(2) mV x s), which was the arbitrary cutoff point set for the discrimination between AML and acute lymphoblastic leukemia (ALL) (mean + 3 x s.d. of ALL samples, n = 10). In addition, five out of seven cases of AML-M0 showed results above the Cutoff point.Conclusion: This highly sensitive enhanced chemiluminescent technique may be applied to discriminate between ALL and AML-M7 or AML-M1 cases, and most AML-M0 cases. It is very simple, cheap and easy to perform compared to other procedures used to measure MPO activity in AML-leukemias including AML-M7 and AML-M0.

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A simple, sensitive and specific agar diffusion bioassay for the antibacterial gatifloxacin was developed using a strain of Bacillus subtilis ATCC 9372 as the test organism. Gatifloxacin could be measured in tablets and raw material at concentration ranging 4-16 mu g ml(-1). The calibration graph for gatifloxacin was linear from 4.0 to 16.0 mu g ml(-1). A prospective validation of the method demonstrated that the method was linear (r(2) = 0.9993), precise (R.S.D. = 1.14%) and accurate. The results confirmed its precision and did not differ significantly from others methods described in the literature. The validated method yielded good results in terms of the range, linearity, precision, accuracy, specificity and recovery. We concluded that the microbiological assay is satisfactory for in vitro quantification of the antibacterial activity of gatifloxacin. (c) 2005 Elsevier B.V. All rights reserved.

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

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Epidemiological studies have provided evidence that high consumption of tomatoes effectively reduces the risk of reactive oxygen species (ROS)-mediated diseases such as cancer. Tomatoes are rich sources of lycopene, a potent singlet oxygen-quenching carotenoid. In addition to its antioxidant properties, lycopene shows an array of biological effects including antimutagenic and anticarcinogenic activities. In the present study, the chemopreventive action of lycopene was examined on DNA damage and clastogenic or aneugenic effects of H2O2 and n-nitrosodiethylamine (DEN) in the metabolically competent human hepatoma cell line (HepG2 cells). Lycopene at concentrations of 10. 25, and 50 mu M, was tested under three protocols: before, simultaneously, and after treatment with the mutagen, using the comet and micronucleus assays. Lycopene significantly reduced the genotoxicity and mutagenicity of H2O2 in all of the conditions tested. For DEN, significant reductions of primary DNA damage (comet assay) were detected when the carotenoid (all of the doses) was added in the cell culture medium before or simultaneously with the mutagen. In the micronucleus test, the protective effect of lycopene was observed only when added prior to DEN treatment. In conclusion, our results suggest that lycopene is a suitable agent for preventing chemically-induced DNA and chromosome damage. (C) 2007 Elsevier Ltd. All rights reserved.

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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

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Buccal mucosa (BM) cells have been used in human biomonitoring studies for detecting DNA adducts and chromosomal damage in an epithelial cell population. In the present study, we have investigated if human BM cells are suitable for use in the single-cell gel electrophoresis (SCGE)/Comet assay as an approach for estimating the exposure of epithelial cells to DNA-damaging agents. Our results indicate that only a few cells from BM cell samples yield comets that can be analyzed by current methods, and that the yield of cells with comets is independent of the percentage of viable BM cells in the sample. Data generated after enzymatic enrichment of viable cells and immunomagnetic separation of epithelial cells suggest that most of the BM cells that do form comets are probably leukocytes. Moreover, by reevaluating specific cells after running the Comet assay, we found that viable epithelial BM cells give rise to atypical comets that are not included in the analysis. Comparing DNA migration patterns between small groups of smokers and nonsmokers indicated that long-term smoking had no effect on the subpopulation of cells that yield typical comets. Our results indicate that the SCGE assay, as it is commonly performed, may not be useful for genotoxicity monitoring in human epithelial BM cells.

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Dental bleaching is a simple and conservative procedure for aesthetic restoration of vital discoloured teeth. However, dental bleaching agents may represent a hazard to human health, especially by causing DNA strand breaks. Genotoxicity tests form an important part of cancer research and risk assessment of potential carcinogens. In the current study, the genotoxic potential associated with exposure to dental bleaching agents was assessed by the single cell gel (comet) assay in vitro. Six commercial dental bleaching agents (Clarigel Gold - Dentsply; Whitespeed - Discus Dental; Nite White - Discus Dental; Magic Bleaching - Vigodent; Whiteness HP - FGM and Lase Peroxide - DMC) were exposed to mouse lymphoma cells in vitro. The results pointed out that all dental bleaching agents tested contributed to the DNA damage as depicted by the mean tail moment. Clear concentration-related effects were obtained for DNA damaging, being the strongest effect observed at the highest dose of the hydrogen peroxide (Whiteness HP and Lase Peroxide, at 35% concentration). on the contrary, Whitespeed (Discus Dental) induced the lowest level of DNA breakage. Taken together, these results suggest that dental bleaching agents may be a factor that increases the level of DNA damage as detected by the single cell gel (comet) assay.

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Objective. In the current study, the potential DNA damage associated with exposure to a number of antimicrobial endodontic compounds was assessed by the single cell gel (comet) assay in vitro.Study design. Chinese hamster ovary (CHO) cells were exposed to formocresol, paramonochlorophenol, calcium hydroxide, or chlorhexidine at final concentration ranging from 0.01% to 1%.Results. Formocresol, paramonochlorophenol, and calcium hydroxide, as well as chlorhexidine in all concentrations tested did not contribute to the DNA damage.Conclusion. These findings are clinically relevant since they represent an important contribution to the correct evaluation of the potential health risk associated with exposure to dental agents.

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The aim of present study was to evaluate frozen canine semen with ACP-106 (R) (Powder Coconut Water) using an in vitro sperm-oocyte interaction assay (SOIA). Ten ejaculates from five stud dogs were diluted in ACP-106 (R) containing 20% egg yolk, submitted to cooling in a thermal box for 40 min and in a refrigerator for 30 min. After this period, a second dilution was performed using ACP-106 (R) containing 20% egg yolk and 12% glycerol. Samples were thawed at 38 degrees C for 1 min. Post-thaw motility was evaluated by light microscopy and by using a computer aided semen analysis (CASA). Plasma membrane integrity and sperm morphology/acrosomal status were evaluated by fluorescent probes (C-FDA/PI) and Bengal Rose respectively. Moreover, frozen-thawed semen was analysed by a SOIA. Subjective post-thaw motility was 52.0 +/- 14.8% and it was significant higher than the total motility estimated by CASA (23.0 +/- 14.8%) because this system considered the egg yolk debris as immotile spermatozoa. Although normal sperm rate and acrosomal integrity evaluated by Bengal Rose stain was 89.6 +/- 3.1 % and 94.3 +/- 3.1 %, respectively, post-thaw percentage of intact plasma membrane was only 35.1 +/- 14.3%. Regarding SOIA, the percentage of interacted oocytes (bound, penetrated and bound and/or penetrated) was 75.3%. Using regression analysis, it was found significant relations between some CASA patterns and data for SOIA. In conclusion, the freezing-thawing procedure using ACP-106 (R) was efficient for maintain the in vitro fertility potential of dog spermatozoa.

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A simple, sensitive and specific plaque assay protocol for the detection of wild type rabies virus in different species is described using confluent monolayers of chicken embryo cells in 6-well plates. Plaques are produced after application of either agarose or Sephadex G-100 overlay onto cell monolayers and incubation for 96 h after virus infection at 37 degreesC. The parameters affecting plaque appearance include cell seeding concentration, overlay composition and time of incubation after infection. Optimal conditions are seeding at a concentration of 4 x 10(6) cell/cm(3), incubation at 37 degreesC in 5% CO2 atmosphere during 96 h, using either 1% agarose or 2% Sephadex G-100 overlays. The described plaque assay would be a new valuable too] in conducting various quantitative investigations, since the chicken embryo cells are susceptible to rabies virus infection from all species studied. (C) 2004 Elsevier B.V. All rights reserved.