Arsenic exposure from drinking water and dyspnoea risk in Araihazar, Bangladesh: a population-based study

Bangladesh has high well water arsenic exposure. Chronic arsenic ingestion may result in diseases that manifest as dyspnoea, although information is sparse. Baseline values were obtained from an arsenic study. Trained physicians ascertained data on dyspnoea among 11,746 subjects. Data were collected on demographic factors, including smoking, blood pressure and arsenic exposure. Logistic regression models estimated odds ratios and confidence intervals for the association between arsenic exposure and dyspnoea. The adjusted odds of having dyspnoea was 1.32-fold (95% CI 1.15-1.52) greater in those exposed to high well water arsenic concentrations (≥ 50 μg · L(-1)) compared with low-arsenic-exposed nonsmokers (p<0.01). A significant dose-response relationship was found for arsenic (as well as smoking) in relation to dyspnoea. In nonsmokers, the adjusted odds of having dyspnoea were 1.36, 1.96, 2.34 and 1.80-fold greater for arsenic concentrations of 7-38, 39-90, 91-178 and 179-864 μg · L(-1), respectively, compared with the reference arsenic concentration of <7 μg · L(-1) (p<0.01; Chi-squared test for trend). Arsenic exposure through well water is associated with dyspnoea, independently of smoking status. This study suggests that mandated well water testing for arsenic with reduction in exposure may significantly reduce diseases that manifest as dyspnoea, usually cardiac or pulmonary.     

A population‐based prospective study of energy‐providing nutrients in relation to all‐cause cancer mortality and cancers of digestive organs mortality

The effect of dietary composition on mortality in low‐income countries is largely unknown. We evaluated whether percentages of dietary energy derived from protein, fat and carbohydrates were associated with all‐cause and cancer mortalities in a Bangladeshi population. Data from a prospective population‐based cohort study of 17,244 men and women were used. Percentages of dietary energy derived from protein, fat and carbohydrates, assessed using a validated food‐frequency questionnaire at baseline, were analyzed in relation to mortality over an average of 9 years (155,126 person‐years) of follow‐up. Cox proportional hazards regression models were used to estimate hazard ratios for all cause, all cancer and cancers of the digestive organs mortalities. Percentage of dietary energy from protein appeared to be significantly associated with cancer mortality. Fully adjusted hazard ratios for cancer mortality in increasing tertiles of percentage of dietary energy from protein were 1.0 (reference), 1.21 (0.73, 2.00) and 1.84 (1.08, 3.15) (p for trend = 0.023). These associations were much stronger for deaths from cancers of the digestive organs with fully adjusted hazard ratios in increasing tertiles of percentage of dietary energy from protein being 1.0 (reference), 2.25 (0.91, 5.59) and 4.85 (1.88, 12.51) (p for trend = 0.001). No significant associations in relation to cancer‐related mortality were observed for percentage of dietary energy from fat. Novel findings from this prospective study show protein is an important risk factor or proxy to an important risk factor for cancer mortality especially from digestive organ cancers in Bangladesh. © 2013 UICC     

A fully automated synthesis of [18F]‐FEAU and [18F]‐FMAU using a novel dual reactor radiosynthesis module

2′‐Deoxy‐2′‐[¹⁸F]fluoro‐5‐substituted‐1‐β‐D ‐arabinofuranosyluracils, including 2′‐deoxy‐2′‐[¹⁸F]fluoro‐5‐methyl‐1‐β‐D ‐arabinofuranosyluracil [¹⁸F]FMAU and [¹⁸F]FEAU are established radiolabeled probes to monitor cellular proliferation and herpes simplex virus type 1 thymidine kinase (HSV1‐tk) reporter gene expression with positron emission tomography. For clinical applications, a fully automated CGMP‐compliant radiosynthesis is necessary for production of these probes. However, due to multiple steps in the synthesis, no such automated synthetic protocols have been developed. We report here a fully automated synthesis of [¹⁸F]‐FEAU and [¹⁸F]‐FMAU on a prototype dual reactor module TRACERlab FX FN. The synthesis was performed by using a computer‐programmed standard operating procedure, and the product was purified on a semipreparative high‐performance liquid chromatography (HPLC) integrated with the synthesis module using 12% EtOH in 50 mM Na₂HPO₄. Finally, the percentage of alcohol was adjusted to 7% by adding Na₂HPO₄ and filtered through a Millipore filter to make dose for human. The radiochemical yield on the fluorination was 40±10% (n=10), and the overall yields were 4±1% (d. c.), from the end of the bombardment; [¹⁸F]FEAU (n=7) and [¹⁸F]FMAU (n=3). The radiochemical purity was >99%, specific activity was 1200–1300 mCi/µmol. The synthesis time was 2.5 h. This automated synthesis should be suitable for production of [¹⁸F]FIAU, [¹⁸F]FFAU, [¹⁸F]FCAU, [¹⁸F]FBAU and other 5‐substitued thymidine analogues. Copyright © 2009 John Wiley & Sons, Ltd.     

Arsenic exposure at low-to-moderate levels and skin lesions, arsenic metabolism, neurological functions, and biomarkers for respiratory and cardiovascular diseases: Review of recent findings from the Health Effects of Arsenic Longitudinal Study (HEALS) in Bangladesh

The contamination of groundwater by arsenic in Bangladesh is a major public health concern affecting 35-75 million people. Although it is evident that high levels (> 300 μg/L) of arsenic exposure from drinking water are related to adverse health outcomes, health effects of arsenic exposure at low-to-moderate levels (10-300 μg/L) are not well understood. We established the Health Effects of Arsenic Longitudinal Study (HEALS) with more than 20,000 men and women in Araihazar, Bangladesh, to prospectively investigate the health effects of arsenic predominately at low-to-moderate levels (0.1 to 864 μg/L, mean 99 μg/L) of arsenic exposure. Findings to date suggest adverse effects of low-to-moderate levels of arsenic exposure on the risk of pre-malignant skin lesions, high blood pressure, neurological dysfunctions, and all-cause and chronic disease mortality. In addition, the data also indicate that the risk of skin lesion due to arsenic exposure is modifiable by nutritional factors, such as folate and selenium status, lifestyle factors, including cigarette smoking and body mass index, and genetic polymorphisms in genes related to arsenic metabolism. The analyses of biomarkers for respiratory and cardiovascular functions support that there may be adverse effects of arsenic on these outcomes and call for confirmation in large studies. A unique strength of the HEALS is the availability of outcome data collected prospectively and data on detailed individual-level arsenic exposure estimated using water, blood and repeated urine samples. Future prospective analyses of clinical endpoints and related host susceptibility will enhance our knowledge on the health effects of low-to-moderate levels of arsenic exposure, elucidate disease mechanisms, and give directions for prevention.     

Brain trace elements in Alzheimer's disease

Instrumental neutron activation analysis has been used to determine the concentrations of 16 elements in selected brain regions and separated gray- and white-matter specimens from histologically verified Alzheimer's disease (AD) and age-matched control patients. Significantly different (p less than 0.05) mean concentrations of Br, Cl, Cs, Hg, N, Na, P, and Rb were observed in AD bulk brain samples compared to controls, while no significant differences were observed for Ag, Co, Cr, Fe, K, Sb, Sc, and Se. The differences that are most persistent and largest in magnitude for the pooled bulk samples, males and females, left and right hemispheres, and separated gray and white matter are the elevation of Br and Hg and the depletion of Rb in AD compared to controls. Significant interelement correlations for the latter elements in both AD and control brains are also documented. Based on these studies, the possibility of an etiological role for trace elements in AD clearly deserves further investigation.     

Pharmacokinetics of the thymidine analog 2'-fluoro-5-methyl-1-beta-D-arabinofuranosyluracil (FMAU) in tumor-bearing rats

The thymidine analog 2'-fluoro-5-methyl-1-beta-D-arabinofuranosyluracil (FMAU) is incorporated into DNA and is resistant to catabolism. We performed pharmacokinetic measurements with [(14)C]FMAU and PET studies with [(11)C]FMAU using rats bearing several different syngeneic tumors. Among normal tissues, FMAU uptake reflected relative cell turnover rates. Among tumors, the highest uptake occurred in a rapidly growing colon carcinoma, but was similarly low in both rapidly and slowly growing prostate tumors. FMAU was not catabolized and was rapidly incorporated into DNA by small intestine and colon tumors. Results indicate that FMAU may be useful for imaging tissue DNA synthesis, although tumor uptake was modest and not well correlated with growth rate among the models examined.     

Instrumental neutron activation analysis of brain aluminum in Alzheimer disease and aging

Instrumental neutron activation analysis procedures were used to determine the aluminum content of various brain regions in histologically verified Alzheimer disease (AD) and in controls. The grand mean aluminum level for 74 AD specimens was 0.372 ± 0.058 μg/gm and for 137 adult controls, 0.467 ± 0.033 μg/gm, both on a wet weight basis. No difference was found at the bulk sample level between AD and adult controls, corrected for age and sex, or when frontal, temporal, and hippocampal specimens were compared. Control specimens (infancy to 85 years) showed an increase in brain aluminum concentration with age. Comparison of freez-dried to wet weight ratios of AD and controls revealed a small increase in water content in AD brains.