In chromosome aberration

Genotoxicity. No reliable data in humans exist to indicate whether methyl parathion may act by a genotoxic mechanism. One study reported a temporary but significant increase in chromatid breaks and stable chromosomal aberrations in two subjects after ingestion of methyl parathion (Van Bao et al. 1974), but another study reported no significant differences in five subjects after ingestion of methyl parathion when compared with 15 controls (Czeizel 1994). A study that involved combined inhalation and dermal exposure of workers to methyl parathion showed no increase in chromosomal aberrations in their... 

Factory workers exposed for an average of 15 years to acrylonitrile vapors showed no increase in chromosomal aberrations in the peripheral lymphocytes (Thiess and Fleig 1978). As in most human studies, the actual concentration of acrylonitrile to which these workers were exposed was not reported. Flowever, monitoring data indicated that the average exposure concentration for the workers was 5 ppm for the majority of the exposure period (approximately 10 years) at the time the study was conducted, acrylonitrile levels in the workplace had been reduced to 1.5 ppm. 

Chloroprene did not cause a significant increase in chromosomal aberrations or sister chromatid exchanges in mice treated in vivo. Both positive and negative results have been reported in a number of in vitro assays. ... 

In in vivo genotoxic assays o-dichloroben-zene induced micronuclei in the bone marrow of mice and was found to bind covalently to DNA, RNA, and proteins. Furthermore, a significant and persistent increase in chromosomal aberrations was observed in the peripheral blood of accidentally exposed workers. 

Methyl methacrylate is not genotoxic in bacterial systems, but it has induced mutation and chromosomal aberrations in vitroP Increases in chromosomal aberrations in bone marrow cells of rats have been observed after in vivo inhalation exposure. ... 

PNA was mutagenic in vitro in some bacterial strains and in chromosomal aberration studies. ... 

In one animal study, a significant increase in lung tumors was observed in female mice exposed by inhalation. Available data indicate a genotoxic potential for sulfur dioxide. Increases in chromosome aberrations and sister chromatid exchanges have been detected in occupationally exposed workers. The lARC has determined that there is limited evidence for the carcinogenicity of sulfur dioxide in experimental animals and inadequate evidence in humans. 

TBBC was not mutagenic in Salmonella typhimurium strains with or without metabolic activation. In Chinese hamster ovary cells, TBBC induced an increase in sister chromatid exchanges but there were no increases in chromosomal aberrations. 

Mutagenesis Oxcarbazepine increased mutation frequencies in the Ames test in vitro in the absence of metabolic activation in 1 of 5 bacterial strains. Oxcarbazepine and MHD produced increases in chromosomal aberrations and polyploidy in the Chinese hamster ovary assay in vitro in the absence of metabolic activation. 

Mutagenesis Human peripheral blood lymphocytes were exposed to zalcitabine, and at 1.5 mcg/mL or more, dose-related increases in chromosomal aberrations were seen. Oral doses of zalcitabine at 2500 and 4500 mg/kg were clastogenic in the mouse micronucleus assay. 

Steinstrasser A. 1981. Biophysical investigations of the dose-effect relationship in chromosome aberrations of human lymphocytes caused by Thorotrast deposits. Radiat Env Biophys 19 1-15. 

Bis(bromomethyl)propane-l,3-diol eaused a dose-related inerease in chromosomal aberrations in Chinese hamster ovary cells, but only at doses that eaused significant cytotoxicity a majority of the breaks were located in the heteroehromatie region of the long arm of ehromosome X, but the reasons for this are unclear. Induetion of sister chromatid exchanges in Chinese hamster ovary cells was judged to be equivoeal. 

Natarajan, A.T. van Kesteren-van Leeuwen, A.C. (1981) Mutagenic activity of 20 coded com-poiuids in chromosome aberrations/sister chromatid exchanges assay using Chinese hamster ovary (CHO) cells. In de Senes, F.J. Ashby, J., eds. Evaluation of Short-Term Tests for Carcinogens. Report of the International Collaborative Program (Progress in Mutation Research, Vol. 1), Amsterdam, Elsevier, pp. 551-559... 

In lymphocytes obtained from six workers employed in 1,4-dioxane production and exposed to unspecified airborne levels of the compound for 6-15 years, no increase in chromosomal aberrations was found relative to that observed in an equal number of controls (Thiess etal., 1996). 

In the more recent cytogenetic studies in occupationally exposed populations, increases in chromosomal aberrations (two studies), micronuclei (one study) and of DNA strand breaks (one study) have been described. These effects have also been observed in rats and mice in some studies and in cultured mammalian cells. DNA adducts have not been detected. 

One study of workers exposed to bisphenol A diglycidyl ether showed no increase in chromosomal aberrations in peripheral blood lymphocytes (lARC, 1989). 

The genetic activity of pure synthetic Maillard products has also been studied. 2-Methylpyrazine, 2-ethylpyrazine, 2,5-di-methylpyrazine and 2,6-dimethylpyrazine all induced a significant increase in chromosome aberrations in Chinese hamster ovary cells... 

Mostly negative results were obtained in animal studies following oral exposure to 2,3,7,8-TCDD. Cytogenetic analysis of the bone marrow did not reveal any increase in chromosomal aberrations in... 

In 2005, a study appeared in Cancer Letters that would have evoked widespread media coverage if it had been about an illegal drug, rather than about a pharmaceutical company product (El-Zein, 2005). Researchers from the University of Texas examined 12 children treated with therapeutic effects of Ritalin to determine whether this central nervous system stimulant produces cytogenetic abnormalities in pediatric patients at therapeutic doses. Using peripheral blood lymphocytes taken from the children, they found a 2.4-fold increase in chromosome aberrations and similar defects. They concluded, These findings warrant further investigations of the possible health effects of methylphenidate in humans, especially in view of the well-documented relationship between elevated frequencies of chromosome aberrations and increased cancer risk. ... 

In a study involving 43 gas-exposed females and 40 gas-exposed males 3 years after the disaster, a signiflcant increase in chromosomal aberration was reported these aberrations included breaks, gaps, and dicentric rings, which were more marked in females than in males (Ghosh et al, 1990). Chromosomal aberrations (Goswami et al, 1985, 1990 Ghosh et al, 1990) and cell cycle abnormalities have been identifled in Bhopal victims (Deo et al, 1987). 

In vitro, nitrofurantoin acts as a mutagen by inhibiting DNA synthetase. In human fibroblast cultures it damages DNA (80). Treatment with nitrofurantoin for 12 months caused a significant increase in chromosome aberrations and sister chromatid exchanges in the lymphocytes of 69 children (81). 

Benzyl alcohol was not mutagenic when tested by the preincubation protocol in the presence or absence of exogenous metabolic activation in the Salmonella assay. A significant increase in chromosomal aberrations was observed after exposure to benzyl alcohol in the presence, but not absence of S9. 

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