Journal de toxicologie clinique et experimentale最新文献

A good monitoring of the exposition to noxious dusts are dependent on physical factors and regulations. They are reviewed, particularly those issued from the work made by the CEN. The main devices available on the French market are described.

After summarizing the various difficulties or uncertainties involved in sampling and measuring procedures at the workplace, two phases to assess workplace exposures are described: an initial appraisal and, when applicable, periodic measurements. The initial assessment includes the identification of potential exposures, the determination of workplace factors, and the assessment of exposures. For exposure measurements, the selection of workers, pattern of sampling and number of samples have to be determined. Conclusions are drawn from the results.

In order to control occupational exposure to gases and vapors, the industrial Hygienist use different sampling instruments and analytical procedures to measure directly or indirectly the gas and vapor concentrations in working atmospheres. The main techniques employed are here described.

Medical surveillance is only one of the ways to estimate the health risk and to assure a good health for workers exposed to atmospheric polluting agents. Occupational practitioner defines himself the forms of this surveillance, according to the risks; excepted a few cases about which legislation determines the minimal contents. Without neglecting clinical exam, in spite of poor and late symptoms, an important place is reserved to biological monitoring: early detection of effects and dosing the product or its metabolites in biological fluids.

Rhône-Poulenc has defined a sampling strategy of the assessment of exposure levels to toxic chemicals at the workplace by inhalation. This strategy is based on the following principles: 1. The exposure measurements must be carried out on carefully selected "homogeneous exposure groups" (HEG). 2. In order to qualify the exposure levels, the strategy specifies a statistical method for estimating the probability of exceeding the professional exposure limit, for a given HEG. 3. Professional judgement is essential in evaluating the risk of professional exposure.

Pralidoxime is the most frequently used antidote in anticholinesterase insecticide poisoning, owing to its cholinesterase reactivating action. The efficiency of Pralidoxime has been retrospectively evaluated by comparing two groups of 31 patients, the first one treated by Pralidoxime in the most commonly used doses (1200mg/24H), the second one untreated. Age, sex and nature of poison were taken in consideration to make a matched distribution in both groups. The clinical and biological initial features were nearly the same in both groups; the other therapeutic measures were the same. There was no statistical difference between the both groups for evolutive criteria such as that mortality, duration of artificial ventilation, intubation, atropine administration, decrease in plasma cholinesterase. The results pleading against the use of Pralidoxime, at least at this dose, in anticholinesterase insecticide poisoning, warrant confirmation by prospective randomized studies. The efficiency of Pralidoxime warrants confirmation firstly in the course of poisonings by some clearly identified insecticides, to which pralidoxime is supposed to be the most effective, cater used in high doses, as recommended by some authors.

Clinical signs of poisonings by beach-trees are reviewed following a recent case report. Painful symptoms are the main features owing to the caustic effect of the plant liquid. However the prognosis is usually good.

Inactivation of cytochrome P-450 dependent monoxygenases, a major family of hepatic oxidative drug-metabolizing enzymes, has been an area of intensive pharmacological and toxicological investigation. Several classes of drugs are known to be inducers or inhibitors of P-450 isoenzymes. The reversible inhibition of the oxidative microsomal metabolism could be directly related to the ability of the drug to bind cytochrome P-450 as shown by the formation of an inhibitory complex. Such effects result in many drug-drug interactions, affect drug disposition and drug action and could interact with the metabolism of endogenous steroids. This review is concerned primarily with a mechanistic interpretation of the reversible interactions between several classes of therapeutic agents and various P-450 isozymes. The effects of structural modifications on the inhibitory activity were also described.

Used as early as 1946 as an analgesic then to treat heroin addicts, the addicting and toxic potential of methadone was quickly recognized. 25 deaths between 1981 and 1986 were reportedly due to methadone in Geneva of which 2 were violent deaths, 9 were caused by a combination of opiates and methadone and 14 were directly related to methadone. Three deaths were noted during the two first weeks of methadone substitutive therapy. Six were noted less than two weeks before leaving jail and 15 were associated with benzodiazepine ingestion. Postmortem blood levels cannot help determine the severity of poisoning neither a causal relationship between methadone and death. Pathological findings as well as the medical history should be taken into consideration.