The kinetic study of the inhibition of human cholinesterases by demeton-S-methyl shows that cholinesterase-based titration methods are not suitable for this organophosphate.

The organophosphorus insecticide, demeton-S-methyl (DSM), is considered as a good surrogate of the highly toxic nerve agent VX for skin absorption studies due to similar physico-chemical properties and in vitro percutaneous penetration profile. But, when skin distribution was estimated by measuring inhibition of cholinesterase activity, the results were poorly reproducible. The various grades of commercial DSM solutions were suspected to be the origin of the discrepancies.

Methodological contributions towards LC-MS/MS quantification of free VX in plasma: An innovative approach.

A novel analytical method has been developed to detect and quantify VX (O-ethyl S-(2(diisopropylamino) ethyl) (methylphosphonothioate)) in plasma using an LC-MS/MS technique. VX detection and quantification in plasma following percutaneous exposure represent a formidable challenge and it is an important part of the ongoing struggle against chemical warfare agents. Liquid-liquid extraction of VX from plasma was performed and it generated a recovery rate of approximately 65% followed by an LC-MS/MS analysis in a 100% organic phase.

Child overdose: the value of the French pharmacovigilance causality assessment method.

Background: In France, the regional pharmacovigilance centres manage drug overdose as adverse drug reactions (ADRs) using the French ADR causality assessment method, and some poison control centres (e.g. in Paris) do likewise for the most serious cases.

High-resolution image cytometry of rat sperm nuclear shape, size and chromatin status. Experimental validation with the reproductive toxicant vinclozolin.

Recent studies have shown that the complex inter-related processes of sperm chromatin organization and nuclear morphogenesis, both of which are important fertility determinants, may be disrupted by chemicals. A high-resolution image cytometry method has been developed, using the fluorescent dye bisbenzimide, for the measurement of 20 features of the sperm nucleus related to size, form and chromatin status in the rat. For the complete set of features measured and from a total of 150 spermatozoa assessed per sample, the overall coefficient of reproducibility was 5%.