[Radioimmunoassay of testosterone concentrations in hair: use in doping control]. / Détermination de la testostérone dans les cheveux par une méthode radio-immunologique. Un test pour dépister le dopage?

The measurement of doping agents in hair is attractive since it offers an increase in retrospective detection of doping with these substances. Hair analysis has a wide window of detection, ranging from months to years, depending on the length of the hair shaft and provides information concerning the pattern of an individual's drug abuse. The aim of the present study was to evaluate the ability of a radioimmunological method to determine physiological concentrations of testosterone in hair. Specimens of hair were collected from four children, nine women and twelve men. None of the subjects was an athlete. Hair samples were weighed, decontaminated and digested in sodium hydroxide. The homogenates were extracted by organic solvent. After evaporation, testosterone was measured by radioimmuno-assay. Hair testosterone concentrations ranged 0.6-2.7 pg/mg, 1.8-6.4 pg/mg and 3.6-23.3 pg/mg for children, women and men respectively. This method is fast and accurate and could have applications in doping control, for screening easily numerous hair samples. GCMS is absolutely necessary to confirm results above 30 pg/mg.

[Pharmaceutical contribution to the non specific challenge in bronchial provocation tests]. / Contribution pharmaceutique a l'exploration de l'hyperréactivité bronchique non spécifique.

Aerosols of methacholine chloride are used in inhalation tests to measure non-specific bronchial responsiveness. Inhalation challenge solutions are not commercially available neither by pharmaceutical industry nor in France by the PCH-APHP. To reply to doctor's request, dilute concentrations of methacholine must be prepared properly in order to protect the patient and to assure doctor of test reproductibility. Osmolarity, pH and degradation of different dilute concentration of methacholine chloride have been compared with two diluents. This study allowed us to validate our preparation of solutions.

Immunoassay of digoxin in hair.

Digoxin analysis in blood is an essential tool for therapeutic drug monitoring in cardiology because compliance with the treatment is a critical issue for the patient. Unfortunately, in postmortem cases blood digoxin concentration is of poor quality because there is a possible drug redistribution in the corpse and because of digoxin-like factors present in some people's blood. On the other hand, no biological fluid can be obtained at the autopsy. The aim of the present study was to evaluate the ability of an immunological method to determine digoxin in hair, in order to confirm that hair analysis can provide information on digoxin use before death. We studied 35 elderly patients who had been taking digoxin (60-250 micrograms/day) for 1-5 years. Two decontamination procedures were tested: washing by dichloromethane or by water and methanol. Three extraction procedures were compared: crushing in a ball mill and chloroform/acetone: crushing and methanol; enzymatic digestion. Immunoassays were performed by a microparticulate enzyme immunoassay. Serum digoxin levels were also assayed when sampling hair. The best results were obtained after decontamination with water and methanol followed by enzymatic digestion. Hair digoxin concentrations range from 3.6 to 11.4 pg/mg. Those very low concentrations are probably due to low and narrow range serum digoxin levels (0.3-1.4 ng/ml). No correlation was found between hair and blood digoxin. A forensic case is presented with 5 pg/mg digoxin in hair.