This study suggests that moderate arsenic exposures from drinking water (<50 micro g/L) during pregnancy are associated with reduction in birth weight, similar in magnitude to that resulting from other environmental exposures such as environmental tobacco smoke and benzene.

In patients with Parkinson's disease, hyperechogenicity of the substantia nigra using transcranial ultrasound has been related to increased tissue concentrations of iron. Recently, deficient iron transport mechanisms in substantia nigra neurons have been described in postmortem tissue of patients with restless legs syndrome (RLS). This study was performed to study substantia nigra echogenicity in RLS patients compared with normal control subjects and Parkinson's disease patients. RLS patients had significantly reduced midbrain areas of hyperechogenicity compared with control subjects, and even more markedly reduced hyperechogenicity compared with Parkinson's disease patients. These findings lend further support to nigral iron deficiency as a pathogenetic factor in RLS.

Chronic arsenic exposure has been associated with a range of neurologic, vascular, dermatologic, and carcinogenic effects. However, limited research has been directed at the association of arsenic exposure and human reproductive health outcomes. The principal aim of this study was to investigate the trends in infant mortality between two geographic locations in Chile: Antofagasta, which has a well-documented history of arsenic exposure from naturally contaminated water, and Valparaíso, a comparable low-exposure city. The arsenic concentration in Antofagasta's public drinking water supply rose substantially in 1958 with the introduction of a new water source, and remained elevated until 1970. We used a retrospective study design to examine time and location patterns in infant mortality between 1950 and 1996, using univariate statistics, graphical techniques, and Poisson regression analysis. Results of the study document the general declines in late fetal and infant mortality over the study period in both locations. The data also indicate an elevation of the late fetal, neonatal, and postneonatal mortality rates for Antofagasta, relative to Valparaíso, for specific time periods, which generally coincide with the period of highest arsenic concentration in the drinking water of Antofagasta. Poisson regression analysis yielded an elevated and significant association between arsenic exposure and late fetal mortality [rate ratio (RR) = 1.7; 95% confidence interval (CI), 1.5-1.9], neonatal mortality (RR = 1.53; CI, 1.4-1.7), and postneonatal mortality (RR = 1.26; CI, 1.2-1.3) after adjustment for location and calendar time. The findings from this investigation may support a role for arsenic exposure in increasing the risk of late fetal and infant mortality.ImagesFigure 1Figure 2Figure 3Figure 4Figure 5

In REM sleep behavior disorder (RBD), several studies focused on electromyographic characterization of motor activity, whereas video analysis has remained more general. The aim of this study was to undertake a detailed and systematic video analysis. Nine polysomnographic records from 5 Parkinson patients with RBD were analyzed and compared with sex- and age-matched controls. Each motor event in the video during REM sleep was classified according to duration, type of movement, and topographical distribution. In RBD, a mean of 54 +/- 23.2 events/10 minutes of REM sleep (total 1392) were identified and visually analyzed. Seventy-five percent of all motor events lasted <2 seconds. Of these events, 1,155 (83.0%) were classified as elementary, 188 (13.5%) as complex behaviors, 50 (3.6%) as violent, and 146 (10.5%) as vocalizations. In the control group, 3.6 +/- 2.3 events/10 minutes (total 264) of predominantly elementary simple character (n = 240, 90.9%) were identified. Number and types of motor events differed significantly between patients and controls (P < 0.05). This study shows a very high number and great variety of motor events during REM sleep in symptomatic RBD. However, most motor events are minor, and violent episodes represent only a small fraction.

Chronic exposure to inorganic arsenic (In-As) from drinking water is associated with different health effects, including skin, lung, bladder, and kidney cancer as well as vascular and possibly reproductive effects. In-As is metabolized through the process of methylation, resulting in the production and excretion of methylated species, mainly monomethylarsenate (MMA) and dimethylarsenate (DMA). Because a large percentage of the dose is excreted in urine, the distribution of urinary In-As, MMA, and DMA is considered a useful indicator of methylation patterns in human populations. Several factors affect these patterns, including sex and exposure level. In this study, we investigated the profile of urinary In-As, MMA, and DMA of pregnant women. Periodic urine samples were collected from early to late pregnancy among 29 pregnant women living in Antofagasta, Chile, who drank tap water containing 40 micro g/L In-As. The total urinary arsenic across four sampling periods increased with increasing weeks of gestation, from an initial mean value of 36.1 to a final value of 54.3 micro g/L. This increase was mainly due to an increase in DMA, resulting in lower percentages of In-As and MMA and a higher percentage of DMA. Our findings indicate that among women exposed to moderate arsenic from drinking water during pregnancy, changes occur in the pattern of urinary arsenic excretion and metabolite distribution. The toxicologic significance of this is not clear, given recent evidence suggesting that intermediate methylated species may be highly toxic. Nevertheless, this study suggests that arsenic metabolism changes throughout the course of pregnancy, which in turn may have toxicologic effects on the developing fetus. Key words: arsenic, arsenic metabolism, arsenic methylation, Chile, pregnancy, urinary arsenic.