Marc André Lefebvre

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In an exploratory study, levels of cadmium in whole-kidney and liver tissues of 314 subjects from the general population of the province of Quebec (Canada) were measured postmortem. Frequency distributions of cadmium concentrations were lognormal. As reported in similar studies, age and especially smoking habits were the main variables affecting cadmium(More)
Diltiazem (DTZ) is a calcium channel blocker widely used in the treatment of angina and hypertension. DTZ undergoes extensive metabolism yielding several metabolites, some of which are active like N-desmethyldiltiazem (MA), desacetyldiltiazem (M1) and N-desmethyl,desacetyldiltiazem (M2). Due to the nature of its biotransformation, several organs should have(More)
Glutathione (GSH) is one of the key components of the lung antioxidant defenses. Chronic smokers have higher GSH concentrations in their epithelial lining fluid than do nonsmokers. The aim of this study was to compare antioxidant concentrations in epithelial lining fluid (ELF) from nonsmokers, smokers with, and smokers without non-small-cell lung cancer.(More)
Blood cadmium levels were measured in 554 persons without any known professional exposure to this metal. They were grouped in three samples; one entirely of 142 Inuit, one of 212 caucasian city dwellers and one of 200 caucasian rural residents. While blood cadmium levels measured in non-smokers are comparable to those reported in published reports, those of(More)
Multiple-dose kinetics of pefloxacin was determined in 12 normal male subjects given 400 mg pefloxacin by iv 1 h-infusion every 12 h for 16 doses. Twelve other subjects (6 men and 6 women) were given 400 mg pefloxacin by mouth every 12 h for 18 doses. Plasma and urine concentrations of pefloxacin and its main metabolites (N-desmethyl pefloxacin or(More)
The 4th Calibration and Validation Group Workshop on Recent Issues in Regulated Bioanalysis, a 2-day full immersion workshop, was organized by the Calibration and Validation Group. Contract research organizations, pharmaceutical companies and regulatory agencies came together to discuss several 'hot' topics concerning bioanalytical issues and regulatory(More)
OBJECTIVE To describe a case of massive diltiazem overdose with a good outcome achieved after early and aggressive supportive therapy. DESIGN Case report. SETTING Pediatric Critical Care Unit. PATIENT Sixteen-year-old adolescent girl. MEASUREMENTS AND MAIN RESULTS A 16-yr-old adolescent girl presented to the emergency department 6 hrs after the(More)
We present an analytical method for the determination of heroin, free 6-acetylmorphine (6-AM), and free morphine in blood, urine, and vitreous humor. This method is used in postmortem cases where heroin is the suspected cause of death. The analytical protocol includes the following steps: liquid-liquid extraction at pH 9.5, propionylation at room(More)
Samples of moose (N = 431) and white-tailed deer (N = 225) liver and kidneys were collected during the 1985 hunting season from 14 zones south of the 50 degree latitude in Québec. Regional differences in cadmium level in the liver were detected and three homogeneous areas were delineated for each species. Uptake was greater for moose than for deer: in the(More)
Samples of kidney, liver, skeletal muscle, heart, mesentery and rumen wall were collected during 1985-1986 in northern Québec from 121 caribou belonging to the Rivière George herd. Significant seasonal variations were found for cadmium concentration in kidneys, liver and skeletal muscles, the level being higher in winter than in autumn. The concentration in(More)