Association between lithium in tap water and suicide mortality rates in Miyazaki Prefecture

BACKGROUND@#Most studies have reported that suicide mortality rates are negatively associated with lithium levels in tap water; however, a few studies showed either no association or a positive association. Thus, the association between suicide mortality and lithium levels in tap water remains controversial. To clarify the association, our study evaluated the association between lithium levels in tap water and suicide mortality rates in Miyazaki Prefecture of Japan, after adjusting for confounding factors.@*METHODS@#We measured lithium levels in tap water across the 26 municipalities of Miyazaki Prefecture in Japan. We examined the standardized mortality ratio (SMR) for suicide in each municipality and used the data as the average suicide SMRs over 5 years (2009-2013). Weighted least-squares regression analysis, adjusted for the size of each municipality's population, was used to investigate the association between lithium levels in tap water and suicide SMRs. In addition to a crude model, in an adjusted model, potential confounding factors (proportion of elderly people, proportion of one-person households, annual marriage rate, annual mean income, unemployment rate, the density of medical doctors per 100,000 people, annual total rainfall, and proportion of people with a college education or higher) were added as covariates.@*RESULTS@#We showed that male and female suicide SMRs were not associated with lithium levels in tap water in Miyazaki Prefecture. After adjusting for confounders, male suicide SMRs were significantly and positively associated with the proportion of elderly people in the population and annual total rainfall, and female suicide SMRs were associated with the proportion of elderly people in the population.@*CONCLUSIONS@#No association between lithium levels in tap water and suicide mortality rates was found in Miyazaki Prefecture.

Peripheral neuropathy induced by drinking water contaminated with low-dose arsenic in Myanmar

BACKGROUND@#More than 140 million people drink arsenic-contaminated groundwater. It is unknown how much arsenic exposure is necessary to cause neurological impairment. Here, we evaluate the relationship between neurological impairments and the arsenic concentration in drinking water (ACDW).@*PARTICIPANTS AND METHODS@#A cross-sectional study design was employed. We performed medical examinations of 1867 residents in seven villages in the Thabaung township in Myanmar. Medical examinations consisted of interviews regarding subjective neurological symptoms and objective neurological examinations of sensory disturbances. For subjective neurological symptoms, we ascertained the presence or absence of defects in smell, vision, taste, and hearing; the feeling of weakness; and chronic numbness or pain. For objective sensory disturbances, we examined defects in pain sensation, vibration sensation, and two-point discrimination. We analyzed the relationship between the subjective symptoms, objective sensory disturbances, and ACDW.@*RESULTS@#Residents with ACDW ≥ 10 parts per billion (ppb) had experienced a "feeling of weakness" and "chronic numbness or pain" significantly more often than those with ACDW  50 ppb). These data suggest a threshold for the occurrence of peripheral neuropathy due to arsenic exposure, and indicate that the arsenic concentration in drinking water should be less than 10 ppb to ensure human health.

Human Glutathione S-transferase A1 polymorphism and susceptibility to oral squamous cell carcinoma in Japanese

<p><b>OBJECTIVES</b>Glutathione S-transferase (GST) A1 catalyses the activated heterocyclic aromatic a mine carcinogenN-acetoxy-2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine (N-OAc-PhIP). This case-control study was carried out to examine whether the genetic polymorphism of GSTA1 is associated with the risk oforal squamous cell carcinoma among Japanese people in relation to their smoking status.</p><p><b>METHODS</b>In this study, 97 Japanese oral squamous cell carcinoma patients and 457 healthy controls were compared for the frequencies of theGSTA1 genotypes ((*) A:-567T,-69C,-52G,(*) B:-567G,-69T,-52A).</p><p><b>RESULTS</b>The frequencies ofGSTA1 (*)A/(*)B+(*)B/(*) B genotypes were 32.3% in male cancer patients and 11.4% in female cancer patients, compared with 20.1% in the male control group (Odds ratio (OR)=1.86; 95% confidence interval (CI) 0.99-3.46) and 23.1% in the female control group (OR=0.58; 95% CI 0.18-1.81). TheGSTA1 (*)A/(*)B+(*)B/(*) B genotypes were associated with an 86% increased risk of oral squamous cell carcinoma among males, albeit without statistical significance. Also, among male smokers, the frequency ofGSTA1 (*)A/(*)B+(*)B/(*) B genotypes was significantly higher among the oral squamous cell carcinoma patients (33.3%) than among the controls (19.6%). The OR of the male smokers with theGSTA1 (*)A/(*)B+(*)B/(*) B genotypes for oral squamous cell carcinoma was 1.97 (95% CI 1.02-3.79).</p><p><b>CONCLUSIONS</b>We present the first evidence of an association betweenGSTA1 (*) B and oral squamous cell carcinoma among smokers. This study suggests that the GSTA1 polymorphism and tobacco smoke-derived PhIP are associated with oral squamous cell carcinoma susceptibility among male smokers.</p>

\it{Human Glutathione S-transferase A1} Polymorphism and Susceptibility to Oral Squamous Cell Carcinoma in Japanese

Objectives: Glutathione S-transferase (GST) A1 catalyses the activated heterocyclic aromatic amine carcinogen N-acetoxy-2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine (N-OAc-PhIP). This case-control study was carried out to examine whether the genetic polymorphism of GSTA1 is associated with the risk of oral squamous cell carcinoma among Japanese people in relation to their smoking status. Methods: In this study, 97 Japanese oral squamous cell carcinoma patients and 457 healthy controls were compared for the frequencies of the GSTA1 genotypes (*A: -567T,-69C,-52G, *B: -567G,-69T,-52A). Results: The frequencies of GSTA1 *A/*B+*B/*B genotypes were 32.3% in male cancer patients and 11.4% in female cancer patients, compared with 20.1% in the male control group (Odds ratio (OR)=1.86; 95% confidence interval (CI) 0.99-3.46) and 23.1% in the female control group (OR=0.58; 95% CI 0.18-1.81). The GSTA1 *A/*B+ *B/*B genotypes were associated with an 86% increased risk of oral squamous cell carcinoma among males, albeit without statistical significance. Also, among male smokers, the frequency of GSTA1 *A/*B+*B/*B genotypes was significantly higher among the oral squamous cell carcinoma patients (33.3%) than among the controls (19.6%). The OR of the male smokers with the GSTA1 *A/*B+ *B/*B genotypes for oral squamous cell carcinoma was 1.97 (95% CI 1.02-3.79). Conclusions: We present the first evidence of an association between GSTA1*B and oral squamous cell carcinoma among smokers. This study suggests that the GSTA1 polymorphism and tobacco smoke-derived PhIP are associated with oral squamous cell carcinoma susceptibility among male smokers.

Genetic polymorphisms ofCYP2A6 andCYP2E1 with tobacco smoking is not associated with risk of urothelial cancer

<p><b>OBJECTIVES</b>To elucidate the association between genetic polymorphisms ofCYP2a6 andCYP2E1 and urothelial cancer susceptibility.</p><p><b>METHODS</b>A total of 137 Japanese patients with urothelial cancer and 217 Japanese healthy controls, frequency-matched for age and gender, were selected. The polymorphisms ofCYP2A6 andCYP2E1 were analyzed by PCR-RFLP, and cigarette smoking histories were obtained through interviews</p><p><b>RESULTS</b>The frequency ofCYP2A6 homozygote deletion genotype was 2.9% in the patients, compared with 3.2% in the controls (OR=0.84, 95% CI 0.24-2.96). The frequencies ofCYP2E1 C1/c2 andC2/c2 were 27.7% and 4.4% in the patients, compared with 35.5% and 6.0% in the controls (OR=0.68, 95% CI 0.42-1.09, OR=0.67, 95% CI 0.24-1.84, respectively). No statistically significant differences were observed when theCYP2A6 homozygote deletion genotype and theCYP2E1 genotypes were examined relative to smoking status.</p><p><b>CONCLUSIONS</b>Our data indicate that neither a relationship between genetically impaired nitrosamine metabolism and tobacco-smoking consumption, nor urothelial cancer risk related to theCYP2A6 deletion genotype andCYP2E1 Rsa I genotype was found in Japanese population.</p>

Genetic Polymorphisms of \it{CYP2A6} and \it{CYP2E1} with Tobacco Smoking is not Associated with Risk of Urothelial Cancer

Objectives: To elucidate the association between genetic polymorphisms of CYP2A6 and CYP2E1 and urothelial cancer susceptibility. Methods: A total of 137 Japanese patients with urothelial cancer and 217 Japanese healthy controls, frequency-matched for age and gender, were selected. The polymorphisms of CYP2A6 and CYP2E1 were analyzed by PCR-RFLP, and cigarette smoking histories were obtained through interviews. Results: The frequency of CYP2A6 homozygote deletion genotype was 2.9% in the patients, compared with 3.2% in the controls (OR=0.84, 95% CI 0.24−2.96). The frequencies of CYP2E1 C1/c2 and C2/c2 were 27.7% and 4.4% in the patients, compared with 35.5% and 6.0% in the controls (OR=0.68, 95% CI 0.42 −1.09, OR=0.67, 95% CI 0.24−1.84, respectively). No statistically significant differences were observed when the CYP2A6 homozygote deletion genotype and the CYP2E1 genotypes were examined relative to smoking status. Conclusions: Our data indicate that neither a relationship between genetically impaired nitrosamine metabolism and tobacco-smoking consumption, nor urothelial cancer risk related to the CYP2A6 deletion genotype and CYP2E1 Rsa I genotype was found in Japanese population.