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Viau CM Cardone JM Guecheva TN Yoneama ML Dias JF Pungartnik C Brendel M Saffi J Henriques JA 《Chemosphere》2012,86(5):477-484
Tin or stannous (Sn2+) compounds are used as catalysts, stabilizers in plastic industries, wood preservatives, agricultural biocides and nuclear medicine. In order to verify the Sn2+ up-take and toxicity in yeast cells we utilized a multi-elemental analysis known as particle-induced X-ray emission (PIXE) along with cell survival assays and quantitative real-time PCR. The detection of Sn2+ by PIXE was possible only in yeast cells in stationary phase of growth (STAT cells) that survive at 25 mM Sn2+ concentration. Yeast cells in exponential phase of growth (LOG cells) tolerate only micro-molar Sn2+ concentrations that result in intracellular concentration below of the method detection limit. Our PIXE analysis showed that STAT XV185-14c yeast cells demonstrate a significant loss of intracellular elements such as Mg, Zn, S, Fe and an increase in P levels after 1 h exposure to SnCl2. The survival assay showed enhanced tolerance of LOG yeast cells lacking the low-affinity iron and zinc transporters to stannous treatment, suggesting the possible involvement in Sn2+ uptake. Moreover, our qRT-PCR data showed that Sn2+ treatment could generate reactive oxygen species as it induces activation of many stress-response genes, including SOD1, YAP1, and APN1. 相似文献
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Coumarin, a carcinogenic lactone, was tested at single oral doses of 60, 30, and 7.5 mg/kg in Wistar rats using the Peritoneal Cell Test. Two weeks after application, the peritoneal cell were scored on the basis of three for colony growth in soft agar for 7 days. The cultures were scored on the basis of three parameters: colony size, colony frequency, and colony survival until day 7. A fourth parameter, namely the presence of giant colonies of 300 to a few thousand cells, was considered as a further confirmation of the potential carcinogenicity of the agent tested. The results showed positive cultures at all three doses tested, thus confirming the known tumorigenicity of coumarin in rats. Giant colonies were observed in the cultures of rats treated both with coumamrin and dimethylnitrosamine (used as a positive control). 相似文献
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Luther GW Glazer BT Hohmann L Popp JI Taillefert M Rozan TF Brendel PJ Theberge SM Nuzzio DB 《Journal of environmental monitoring : JEM》2001,3(1):61-66
Sulfur speciation was determined in real time in salt marsh microbial mats, subtidal sediments and hydrothermal vent diffuse flow waters using solid state gold-amalgam voltammetric microelectrodes. Chemical species were measured in situ without any sample manipulation or processing. The partially oxidized sulfur species detected were polysulfides, thiosulfate, elemental sulfur and tetrathionate. Fe(III) oxidation of hydrogen sulfide does not occur within the mats where microbially mediated processes are responsible for oxidation of H2S. In sediments and diffuse flow vent waters, Fe(III) phases are the direct oxidant of H2S. Sulfur speciation determined in this work is due to in situ biogeochemical processes and is not due to artefacts of sample manipulation. The voltammetric data show that polysulfides are the first detectable intermediate during sulfide oxidation which is consistent with previous laboratory studies. 相似文献
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The work was supported by the Award for the Advancement of European Science from the Koerber-Stiftung and by Dornier Medizintechnik. 相似文献
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