917 resultados para aquatic toxicology


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ABSTRACT: The present study intended to characterize the phenotypic and genetic diversity of Brazilian isolates of Chromobacterium violaceum from aquatic environments within the Amazon region. Nineteen isolates showed morphological properties of C. violaceum and the majority grew at 44°C. Low temperatures, in contrast, showed to be inhibitory to their growth, as eleven isolates did not grow at 10ºC and nine did not produce pigmentation, clearly indicating an inhibition of their metabolism. The largest variation among isolates was observed in the citrate test (Simmons), in which 12 isolates were positive, and in the oxidation/fermentation of sucrose, with six positives isolates. Chloramphenicol, gentamicin and sulfonamides efficiently inhibited bacterial growth. Amplified products of the recA gene were digested with HindII or PstI, which produced three or four restriction fragments patterns, respectively. The combined analysis arranged the isolates into six genospecies. The higher diversity observed in Belém (genotypes C, D, E and F) may be a consequence of intense human occupation, pollution of the aquatic environment or due to the higher diversity of the environments sampled in that region. In conclusion, a high level of genetic and phenotypic diversity was observed, and four new genospecies were described.

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This study had as main objectiveto evaluate the influence of AHS obtained from an area under sugarcane cultivation on the dynamics of chromium species (Cr(III) and Cr(VI)). Was studied complexing capacity (CC) with the AHS of chromium species and these were characterized using UV/Vis spectrophotometry, molecular fluorescence, elemental analysis and infrared. AHS with and without fractionation showed a greater aromaticity degree and a predominance of humic acids, and the E4/E6 and E2/E4 ratios suggested aromatic rings and a greater contribution from plants, which indicates lignin structures. The highest CCs were observed for the AHS fractionated, being fraction with molecular-size < 10 kDa and 10-30 kDa showed the highest ability to complex Cr(III) and Cr(VI) ions, respectively. These results are corroborating with C/H/N and UV/Vis data, where we can conclude that the AHS without fractionation had the greatest aromaticity and a predominance of humic acids in their structure.

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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

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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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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

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Ethnopharmacological relevance: In Brazil, a phytotherapeutic preparation produced from a standardized tincture of Cinchona calisaya Weddel such that each mL of product contains 400 mu g of quinine, known in Portuguese as Agua Inglesa (R) (English water), is indicated by the manufacturer as a tonic, appetite stimulant, and digestive. However, this preparation has long been used in folk medicine as a female fertility stimulant. Despite its widespread use in folk medicine to stimulate female fertility, no study has been undertaken to assess the potential teratogenic and genotoxic effects of this phytotherapeutic preparation. The aim of the present study was to investigate possible toxic reproductive effects in mice caused by exposure to Agua Inglesa (R), either before mating or during the pre- and post-embryo implantation periods. The genotoxic potential was evaluated using the micronucleus assay.Material, Methods, and Results: Virgin female mice, with at least one estrous cycle evidenced by vaginal cytology, were divided into five groups of 15 individuals each (Group I - control, Group II - treated with ethanol solution at 16%, Groups III, IV and V treated with phytotherapeutic preparation at 1.5 mL/kg/day, 3.0 mL/kg/day and 4.5 mL/kg/day, respectively). After the first 28 days of treatment, females were caged individually with adult fertile males. Pregnant females continued to receive treatment for seven days (preimplantation period). Body weight was recorded weekly during treatment. Signs of toxicity (weight loss, food intake, piloerection, apathy, prostration, diarrhea, seizures, behavioral changes, and locomotion) were also observed. The females were sacrificed on the 15th day of pregnancy, uterine horns were evaluated for implantation, and the placental index was recorded. In the micronucleus test, 2000 polychromatic erythrocytes (PCE) per animal, obtained from bone marrow, were scored. Results The results showed that exposure of the females during the pre- and post-implantation periods did not significantly alter the reproductive capacity (p < 0.05); however, in higher dose (three times human dose)reduction of fetal weight was observed. There was no difference between the control and phytotherapeutic preparation (p > 0.05) in terms of the average number of micronucleated polychromatic erythrocytes.Conclusions: Although folk medicine suggests that the Agua Inglesa (R) preparation is useful as a female fertility stimulant, no such effect was confirmed in mice. (C) 2014 Elsevier Ireland Ltd. All rights reserved.

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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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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)