Methylation Study of a Population Environmentally Exposed to Arsenic in Drinking Water

Hopenhayn‐Rich, Claudia; Biggs, Mary L.; Smith, Allan H.; Kalman, David A.; Moore, Lee E.

doi:10.2307/3433091

Cited by 31 publications

(52 citation statements)

References 32 publications

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“…Factors which have been shown to in8uence the methylation of arsenic include dose level, age, and to some extent gender (Vahter, 1999). In people exposed to inorganic arsenic via the drinking water in northern Chile, women had about 3% more DMA and less MMA in the urine than men (Hopenhayn-Rich, 1996). Similar gender differences were found in northeastern Taiwan (Hsu et al, 1997), but not in other studies (Kurttio et al, 1998).…”

Section: Arsenicmentioning

confidence: 67%

Metals and Women's Health

Vahter

Berglund

Åkesson

et al. 2002

Environmental Research

282

154

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Section: Arsenicmentioning

confidence: 67%

Metals and Women's Health

Vahter

Berglund

Åkesson

et al. 2002

Environmental Research

282

154

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“…The average distribution of urinary arsenic metabolites in human subjects exposed to arsenic occupationally, experimentally, or in the general environment, is generally 10 to 30% for iAs, 10 to 20% for MMA, and 60 to 80% for DMA (Vahter,2000). However, arsenic metabolism was affected by a variety of factors, such as nutrition (Gamble et al,2005), genetics (Chung et al,2002), sex (Shraim et al,2003; Tseng et al,2005), and age (Chowdhury et al,2003; Tseng et al,2005); a considerable individual variation in arsenic methylation was found even when exposed to the same level of arsenic (Hopenhayn‐Rich et al,1996; Loffredo et al,2003; Sun et al,2007). The individual variation in the metabolism of arsenic may be potential interpretation for the individual variation in the susceptibility to arsenic‐related health problems (Tseng,2007).…”

Section: Discussionmentioning

confidence: 99%

“…Our results meant that the capacity of arsenic methylation was decreased with the consecutive administration, and there were more arsenic cumulative toxicity in APL patients after the treatment. Epidemiologic studies from endemic arsenic exposure areas had shown that higher urinary MMA proportion and lower DMA proportion were associated with the incidence of peripheral vascular disease (Tseng et al,2005), bladder cancer (Chen et al,2003b,2005 ), skin lesion (Del Razo et al,1997; Hopenhayn‐Rich et al,1996), and even skin cancer (Hsueh et al,1997; Chen et al,2003a). The potential explanation for the association between urinary arsenic metabolites and human diseases can be that higher MMA proportion and lower DMA proportion in urine may increase the chance of cellular exposure to the more toxic forms of MMA III (Tseng,2007).…”

Section: Discussionmentioning

confidence: 99%

Arsenic methylation metabolism and liver injury of acute promyelocytic leukemia patients undergoing arsenic trioxide treatment

Shi

Liu

Zheng

et al. 2011

Environmental Toxicology

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Although arsenic is effective in the treatment of acute promyelocytic leukemia (APL), as a well-known environmental toxicant, the side effects of arsenic treatment and arsenic methylation metabolism of the patients are rarely reported. In this manuscript, we investigated 23 APL patients treated with 10 mg arsenic trioxide daily, detected the arsenic metabolites in urine samples collected on the 0, 10th, and 20th day of arsenic treatment. At the same time, liver function and blood routine examination were also investigated in these APL patients. We found that, urinary monomethylated arsenic proportion (MMA%) increased, but dimethylated arsenic proportion (DMA%), the first methylation ratio (FMR) and the secondary methylation ratio (SMR) decreased with consecutive administration of arsenic trioxide. After adjustment for age impact, no statistical difference was observed in urinary arsenic concentrations and arsenic methylation capacity between male and female at the same treatment time point. During arsenic trioxide treatment of APL, transient elevation of serum aminotransferases was found in the blood samples, which indicated that liver injury occurred and probably reversible. Leukocytosis developed in 5 of the 23 patients with the administration of arsenic trioxide. No statistical difference was observed in the other blood routine examination parameters. These results demonstrated that the capacity of arsenic methylation decreased and transient liver injury occurred during arsenic trioxide treatment of APL, which indicated that the side effects of clinical arsenic treatment can not be ignored.

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“…The hypothesis that cigarette smoking increases susceptibility to the risk of premalignant skin lesion due to arsenic exposure is suggested by previous studies on lung cancer (Ferreccio et al, 2000; Chen et al, 2004) and bladder cancer (Steinmaus et al, 2003; Karagas et al, 2004). Cigarette smoking has been associated with a lower methylation capacity of arsenic, as indicated by a higher ratio of urinary monomethylarsonate to dimethylarsinate in smokers (Hopenhayn‐Rich et al, 1996). Moreover, tobacco smoking may increase the requirement of folate, a critical cofactor in one‐carbon metabolism, a process through which arsenic is enzymatically methylated (Gamble et al, 2005).…”

Section: Application To Smoking and Arsenicmentioning

confidence: 99%

Inference for Causal Interactions for Continuous Exposures under Dichotomization

2011

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Summary Dichotomization of continuous exposure variables is a common practice in medical and epidemiologic research. The practice has been cautioned against on the grounds of efficiency and bias. Here we consider the consequences of dichotomization of a continuous covariate for the study of interactions. We show that when a continuous exposure has been dichotomized certain inferences concerning causal interactions can be drawn with regard to the original continuous exposure scale. Within the context of interaction analyses dichotomization and the use of the results in this paper can furthermore help prevent incorrect conclusions about the presence of interactions that result simply from erroneous modeling of the exposure variables. By considering different dichotomization points one can gain considerable insight concerning the presence of causal interaction between exposures at different levels. The results in this paper are applied to a study of the interactive effects between smoking and arsensic exposure from well water in producing skin lesions.

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Methylation Study of a Population Environmentally Exposed to Arsenic in Drinking Water

Cited by 31 publications

References 32 publications

Metals and Women's Health

Metals and Women's Health

Arsenic methylation metabolism and liver injury of acute promyelocytic leukemia patients undergoing arsenic trioxide treatment

Inference for Causal Interactions for Continuous Exposures under Dichotomization

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