The congenital anomalies registry in Belarus: A tool for assessing the public health impact of the Chernobyl accident

A national population-based malformation registry (BNR) has been in operation since 1979 in Belarus, one of the countries most heavily exposed to the contamination from the Chernobyl accident of 26 April 1986. We describe its methodology and its compliance with established criteria, evaluate the completeness of its reporting, and analyze the data collected in four administrative regions with contrasting contamination levels from 1983 through 1999. Nine easily diagnosed malformations have been monitored since 1983. Reporting completeness exceeds 85% for all periods and all regions. In all periods, the prevalence at birth of these malformations was lower in the most contaminated regions and showed a similar positive time trend in areas of low and high contamination. We conclude that the BNR is a reliable tool for studying the possible effects on congenital malformations caused by the Chernobyl accident. Although the trend we observed may be explained by better ascertainment and prenatal diagnosis, a real increase cannot be ruled out. © 2003 Elsevier Inc. All rights reserved

Reducing Current Spread by Use of a Novel Pulse Shape for Electrical Stimulation of the Auditory Nerve

Improving the electrode-neuron interface to reduce current spread between individual electrodes has been identified as one of the main objectives in the search for future improvements in cochlear-implant performance. Here, we address this problem by presenting a novel stimulation strategy that takes account of the biophysical properties of the auditory neurons (spiral ganglion neurons, SGNs) stimulated in electrical hearing. This new strategy employs a ramped pulse shape, where the maximum amplitude is achieved through a linear slope in the injected current. We present the theoretical framework that supports this new strategy and that suggests it will improve the modulation of SGNs’ activity by exploiting their sensitivity to the rising slope of current pulses. The theoretical consequence of this sensitivity to the slope is a reduction in the spread of excitation within the cochlea and, consequently, an increase in the neural dynamic range. To explore the impact of the novel stimulation method on neural activity, we performed in vitro recordings of SGNs in culture. We show that the stimulus efficacy required to evoke action potentials in SGNs falls as the stimulus slope decreases. This work lays the foundation for a novel, and more biomimetic, stimulation strategy with considerable potential for implementation in cochlear-implant technology

Occupational exposure to organic solvent mixtures during pregnancy and the risk of non‐syndromic oral clefts

International audienceOBJECTIVES: To examine the association between maternal occupational exposure to mixtures of organic solvents during pregnancy and the risk of non-syndromic oral clefts. METHODS: A case-control study (164 cleft lip with/without cleft palate (CL/P), 76 cleft palate (CP), 236 controls) was conducted in France to investigate the role of maternal occupational exposure to organic solvents at the beginning of pregnancy in the risk of non-syndromic oral clefts. An expert chemist, guided by a detailed description of the women's occupational tasks, assessed exposure for each. Analysis of the findings used logistic regression. RESULTS: In the control group, 39% of the women who reported working during pregnancy were exposed to at least one type of organic solvent. The risk of oral clefts was associated with oxygenated (for CL/P: OR = 1.8, 95% CI 1.1 to 2.9; and for CP, OR = 1.4, 95% CI 0.7 to 2.7), chlorinated (OR = 9.4, 95% CI 2.5 to 35.3; OR = 3.8, 95% CI 0.7 to 20.7), and petroleum (OR = 3.6, 95% CI 1.5 to 8.8; OR = 1.2, 95% CI 0.3 to 4.9) solvents. The risk of oral clefts increased linearly with level of exposure within the three subgroups of oxygenated solvents we considered (aliphatic alcohols, glycol ethers, and other oxygenated solvents, including esters, ketones, and aliphatic aldehydes). CONCLUSIONS: Results suggest that maternal occupational exposure to organic solvents during pregnancy may play a role in the aetiology of oral clefts. The limited number of subjects and the problem of multiple exposures require that these results be interpreted cautiously

A coupled clinical-experimental approach for estimating real CI stimulation artifacts

International audienc