In Alcaligenes eutrophus CH34, determinants encoding inducible resistance to chromate (chr) and to cobalt and nickel (cnr) are located adjacent to each other on plasmid pMOL28. To develop metal-sensing bacterial strains, a cloned part of plasmid pMOL28, which contains both determinants, was mutated with Tn5-lacZ. The chr::lacZ fusions were specifically induced by chromium; cnr was induced best ...

The effects of thiol compounds (L-cysteine ethyl ester, 2,3-dimercaptosuccinic acid, or 2,3-dimercapto-1-propanesulfonic acid) on the toxicity induced by chromate (potassium dichromate) were investigated in HeLa cells and mice. Chromate-induced cytotoxicity evaluated by inhibition of cell growth and chromium content of the cells was diminished by all of the thiol compounds tested when the cells...

Chromate is an established human carcinogen. There have been many studies of the reactivity of chromate aimed at improving understanding of chromate toxicity. In the present paper a number of conclusions of these studies are reviewed and considered in the light of new results obtained in our laboratories. A number of hypotheses are considered; it is concluded, however, that it is impossible to ...

WATANABE, M., TAKAYAMA, Y., KOIKE, M. and YAMAMOTO, M. In Vivo Clastogenicity of Lead Chromate in Mice. Tohoku J. exp. Med., 1985, 146 (3), 373-374 Cytogenetical effects of lead chromate were evaluated in vivo. When 0.5, 1, 2 and 4 g/kg body weight of lead chromate suspensions in 0.5% gum arabic were administered i.p. to C57BL/6N male mice twice, the frequencies of micronucleated polychromatic ...

The geno- and cytotoxicity of chromate, an important environmental pollutant, is partly attributed to the flavoenzyme-catalyzed reduction with the concomitant formation of reactive oxygen species. The aim of this work was to characterize the role of NAD(P)H:quinone oxidoreductase (NQO1, DT-diaphorase, EC 1.6.99.2) and glutathione reductase (GR, EC 1.6.4.2) in the mammalian cell cytotoxicity of ...

Hexavalent chromium (Cr(VI)) is a serious environmental pollutant and human toxicant. Mammalian cells are very sensitive to chromate as they lack efficient chromate detoxifying strategy, e.g., chromate-reducing genes that are widely present in prokaryotes. To test whether introduction of prokaryotic chromate-reducing gene into mammalian cells could render higher chromate resistance, an Escheric...

Key words: mineral/water interface, reduced Fe minerals, natural attenuation To address the potential for abiotic natural attenuation of chromate, we have studied the kinetics and mechanism of chromate removal in the presence of hydroxycarbonate green rust. The kinetics of chromate removal were studied in batch systems to evaluate the effect of green rust surface area and pH. The rate of chroma...

Inhalation of soluble chromium(VI) is firmly linked with higher risks of lung cancer in humans. However, comparative studies in rats have found a high lung tumorigenicity for moderately soluble chromates but no tumors for highly soluble chromates. These major species differences remain unexplained. We investigated the impact of extracellular reducers on responses of human and rat lung epithelia...

The effects of chromate on sulfate uptake and assimilation were investigated in the accumulator Brassica juncea (L.) Czern. Seven-day-old plants were grown for 2 d under the following combination of sulfate and chromate concentration: (i) no sulfate and no chromate (-S), (ii) no sulfate and 0.2 mmol L(-1) chromate (-S +Cr), (iii) 1 mmol L(-1) sulfate and no chromate (+S), or (iv) 1 mmol L(-1) s...

Various chemicals can be added to urine specimens collected for drug analysis to abnormally elevate ionic concentrations and/or interfere with either immunoassay urine drug-screening procedures or gas chromatographic-mass spectrometric confirmation techniques. One such adulterant, "Urine Luck" (formula 5.3), has been identified in our previous research to contain potassium dichromate. Screening...