980 resultados para Chemical arms control.


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

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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

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The efficacy of sulfadoxine + trimethoprim in comparison to management measures for the control of Eimeria parasitism was studied in naturally infected sheep that were raised in a feedlot and were clinically asymptomatic for eimeriosis. Weight gain was also evaluated in these animals. The following groups were formed with 15 animals/group: TO!, control animals that received saline solution and maintenance of the same management measures that were performed before the study; T02, animals that received two intramuscular doses of sulfadoxine (20 mg/kg) + trimethoprim (4 mg/kg) with a 14-day interval; T03, sheep that received two intramuscular doses of sulfadoxine (20 mg/kg) + trimethoprim (4 mg/kg) with a 14-day interval plus management measures (wood shaving bedding was changed every Monday, and 30g of ammonium sulfate were applied to the bedding and other facilities were performed every Thursday, 10 mL/20 L of water); and T04, animals that received only the management measures described for the previous group. The highest efficacy rates (arithmetic mean) for the T02 group (sulfadoxine + trimethoprim at days 0 and 14) were 21.04% and 21.98% on the 14th and 28th days after the first treatment (DAFT), respectively. However, the treatment showed efficacy rates below 17% and was totally ineffective from the 70th DAFT to the end of the study. In both the T03 (chemical treatment+ management) and T04 (management only) groups, a significant (P <= 0.05) reduction of oocyst shedding per gram of feces was observed in the animals from the 14th DAFT in comparison to the control group; however, an efficacy rate above 90% was observed from the 28th DAFT. Animals belonging to the T02, T03 and T04 groups presented with alterations in weight gain of 0.57 kg, 4.30 kg and 4.53 kg, respectively, in comparison with the control animals (T01) throughout the 91-day study period. Thus, it is possible to conclude that the two-dose sulfadoxine + trimethoprim treatment, given with a 14-day interval, had little no effect on the oocyst shedding. Moreover, the adopted management measures were enough to cause a significant decrease in the animal parasite loads. (C) 2013 Published by Elsevier B.V.

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

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Parasitic diseases constitute one of the main problems affecting livestock; however the use of chemical medicaments provides drug resistance residues in animal and environmental contamination. Changes in production concepts require that food must be produced in hygienic conditions, per healthy animals and that are not eliminating antibiotic residues, pesticides or other drugs. This scenario has favored organic production and the use of medicinal plants. For the control of endoparasites, several studies have published the benefits of Azadirachta indica A. Juss., Punica granatum Linn., Musa sp., Operculina hamiltonii G. DON., propolis, among others. However, despite the existence in- vitro studies that demonstrate the pharmacological properties of phytotherapics, there is still need for clinical trials to determine dosage and its effects in- vivo. Investigations of new bioactive natural substances can be of great value for the control of animal health and food safety, which is particularly important for organic production systems in which the use of chemical drugs is a limiting factor for certification.

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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

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Acalypha californica Benth., is a plant in the northwestern region from Mexico, commonly known as "cancer herb" and used in traditional medicine for treating cancer. In the present study we have investigated the antiproliferative activity of methanolic extract of A. californica and its fractions in cancer cell lines and phytochemical analysis and mechanism of apoptosis of the fractions with antiproliferative activity. The antiproliferative activity of methanol extract and its fractions of solvents were evaluated by MTT assay against the M12.A(k).C3.F6, RAW 264.7, HeLa and L929 cell lines. Active fractions were fractionated by molecular exclusion chromatography, HPLC and MPLC. The identification of compounds was performed by NMR and FIA-ESI-IT-MS/MS analysis. Apoptotic mechanism was analyzed by flow cytometry, determining the reduction in the mitochondrial membrane potential (JC-1) and the activity of caspases 3,8 and 9. Cell viability assays showed that the hexane fraction of the methanol extract of the plant has significant effects against cancer lines RAW 264.7 (IC50 = 52.08 +/- 1.06 mu g/mL) and HeLa (IC50 = 46.77 +/- 1.09 mu g/mL), the residual fraction showed a selective effect on cell lines M12.A(k).C3.F6 (IC50 = 59.90 +/- 1.05 mu g/mL), RAW 264.7 (IC50 = 58.93 +/- 1.26 mu g/mL) and HeLa (IC50 = 50.11 +/- 1.135 mu g/mL) compared to the control cell line L929 (IC50 = 100.00 +/- 1.09 mu g/mL). The chemical characterization of the active fractions allowed the identification of p-sitosterol and stigmasterol in hexane fraction and some phenolic acids, proanthocyanidins and flavonoids in the residual fraction. The methanol extract and hexane fraction reduces mitochondrial membrane potential significantly and activates caspases 3, 8 and 9. Because of the antiproliferative activity observed, our results provide a rational basis for the use of extracts of A. californica in treating various types of cancer in traditional medicine from Mexico. The extracts induce apoptosis via activation of caspases. (C) 2015 Elsevier B.V. All rights reserved.

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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

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Selective chemical sympathectomy of the internal sex organs of adult male rats was undertaken by long term administration of low doses of guanethidine. The spermatogenic activity of the testis was unaffected by treatment. Examination of the vas deferens using morphometric methods revealed a marked increase in luminal area in contrast to a decrease in muscle layer area and in epithelial height. This is morphological evidence of sperm accumulation caused by a disorder in ductal contractile activity. No structural changes were observed in the epididymis. However, the concentration of spermatozoa in the sperm suspension stored in the cauda epididymidis was significantly increased in denervated rats. This result is discussed in terms of a sympathetic control of resorption mechanisms in the epididymis.

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This study aimed to evaluate the efficacy of chemical agents to increase the bleaching effectiveness of 10% carbamide peroxide. Two hundred and ninety enamel-dentin discs were prepared from bovine incisors. The color measurement was performed by a spectrophotometer using the CIE L*a*b*system. The groups were divided according to the bleaching treatment: negative control group (NC): without bleaching; positive control group (PC): bleached with 10% carbamide peroxide gel without any chemical activator; Manganese gluconate (MG); Manganese chloride (MC); Ferrous gluconate (FG); Ferric chloride (FC); and Ferrous sulphate (FS). Three different concentrations (MG, MC, FG, FC: 0.01, 0.02 and 0.03% w/w; FS: 0.001, 0.002 and 0.003% w/w) for each agent were tested. The bleaching gel was applied on the specimens for 8 h, after which they were immersed in artificial saliva for 16 h, during 14 days. Color assessments were made after 7 and 14 days. The data were analyzed by repeated measures analysis of variance and Tukey's test (5%). Generally, the test groups were unable to increase the bleaching effect (ΔE) significantly compared to the PC group. Only for ΔL, significant higher values compared to the PC group could be seen after 7 days in groups MG (0.02%), and FS (0.002 and 0.003%). The NC group showed significantly lower values than all tested groups. It was concluded that for home bleaching procedures, the addition of chemical activators did not produce a bleaching result significantly higher than the use of 10% carbamide peroxide without activation, and that the concentration of chemical activators used did not significantly influence the effectiveness of treatment.