Toxicological European research. Recherche europeenne en toxicologie最新文献

The authors studied the neuro endocrinological effects of three pesticides. Two of them were organophosphorus compounds (ethyl parathion and dimethoate) and one was a carbamate (zineb). Mature female rats have been orally administered these compounds for 16 days at respectively 1/25, 1/10 and 1/10 of the LD50. The parameters recorded are: the gonadotropins, the length of estrous cycle and the weight of the anterior pituitary gland, the ovaries and the uterus. In contradistinction with the organochlorine compounds the organophosphorus did not induce any disturbances in the neuro endocrinological system, whereas the carbamate compound decreased the pituitary gonadotropins.

Neurophysiological studies were carried out in six female workers of an electromechanical works after accidental exposure to toluene vapours. Electroencephalographic abnormalities and vestibular hyporeflexia were detected immediately after the accident. Six months later the EEG changes were still present, while vestibular findings were found to be markedly improved. Results of this study provide further evidence of the diagnostic value of vestibular investigations after toxic exposure to toluene.

Since the japanese mass poisoning in 1954's, classically named today "Minamata disease", mercury and its derivatives occupy a place of choice into the most worrying chemical pollutants for the human health and a lot of studies about the pathways by which mercury enters in its biogeochemical cycle or the environmental mercury levels are resumed in this paper. The most important aspects of mercury ecotoxicology are reviewed here: biological methylation reaction, bioaccumulation and biomagnification of these toxics in te aquatic ecosystems. The authors also describe the mercury and methylmercury metabolism and the symptomatology of the methylmercurial poisoning; with emphasis that infraclinic chronical manifestations, or large epidemiological interest, are not well known. It should be necessary to found a sensitive biochemical test, specific of this intoxication. The studies about the initial body burden assessment or the threshold values of mercury in easily obtainable specimens (blood hair) are only available for a statistical distribution. At individual levels, a number of factors occur, particularly the presence of selenium who should act as a biological antagonist of methylmercury.

The effects of a 3-month experimental contamination with a commercial mixture of PCBs, DP5 (corresponding to Aroclor 1254) have been studied on groups of 25 SWISS female mice, at levels of 0, 10, 50 and 250 ppm added at feeding. After subcutaneous injection of 0,2 ml of Ehrlich's tumoral ascites liquid, the evolution of tumors as well as the mortality level, were different in the treated groups as compared to the control group. The percentages of mortality due to tumors were the following: control (0 ppm) = 50% 10 ppm = 5% 50 ppm = 5% 250 ppm = 35% Thus, contamination by PCBs seems to have protected these mice against the Ehrlich tumor. No decrease in body weight was noted neither were differences in size or appearance of the thymus and the spleen in the treated mice; an evident liver hypertrophy was noted in all PCB treated mice.

Female rats were exposed to hydroxyfluoride (2.7 mg/m3 or 5.0 mg/m3) seven weeks before pregnancy during pregnancy and lactation as well as subsequently with the offsprings up to 1, 2, 4 and 6 months after birth. The offspring was taken for investigations. It was found that serum hydroxyproline and hydroxylysine was elevated in growing rats exposed to hydrofluoride. The elevation was higher in animals inspired to 5.0 mg/m3 than in rats treated with 2.7 mg/m3. One- and two-months old rats were shown to be more suitable to hydrofluoride. Similar changes were observed in urinary excretion of these compounds. Changes in collagen content were found in skin and lungs. A marked decrease total collagen content and changes in collagen fractions were shown.