Toxicological European research. Recherche europeenne en toxicologie最新文献

The soluble glutathione S-transferase (GST) isoenzymes from rat testicular tissue were separated in one chromatographic run on carboxymethyl cellulose. GST was measured with 1-chloro-2,4-dinitrobenzene as the second substrate. The following percentages for the different isoenzymes were found: GST AA: 12.6%, GST A:8.1%, GST B:4.2%, GST C:18.1%, GST D and E: not detected, GST x:7.4%, and anionic GST:49.6%. These values were quite different from those found in liver tissue. Testicular GST could not be induced by the drug metabolizing enzyme inducers trans-stilbene oxide, DDT, and phenobarbital. The high GST content in rat testes may suggest that these enzymes function also in this tissue in the metabolism and detoxification of electrophilic xenobiotics.

The control of the air pollution by cadmium in Marseille was realized between July 1st 1977 and June 30 1979 by determining the metal in the air dust by atomic absorption spectrophotometry without flame. The samples were taken on eight different stations located in the urban-center and in the suburbs. The atmospheric levels of cadmium in Marseille are low but a note-worthy increase was noticed from september 1978. A principal components analysis of the data compared with these obtained with other atmospheric pollutants, revealed the particular characteristic of cadmium in Marseille, which seems to be bound neither with the pollutants issued from motor vehicles, nor with zinc of which it is yet an impurity. However vigilance is indispensable against the environmental contamination by cadmium in consideration of its potential risks for the health.

Plasma acetate is extracted using ethanol in alkaline medium, in presence of internal standard. After concentration of the hydroalcoholic phase, the chromatographic analysis is performed utilizing 10% SP 1200 and 1% H3PO4 on chromosorb W. The linearity of the method has been tested from 0.05 to 10 mM/I, its reproducibility is +/- 3.5% for levels ranging from 0.1 to 10 mM/I and +/- 10% for those smaller than 0.1 mM/I. This method is sensitive enough to assess the physiological acetate levels and those obtained after ethanol biotransformation.

Residues of veterinary drugs can be found in human food and be involved in allergic untoward reactions in consumers. The current french law on veterinary pharmacy allows to control this risk. Therefore, to evaluate this risk the following topics are considered: 1) origin of food contamination by allergenic compounds and characteristics of residues, 2) effects of these residues. Observations demonstrate that residues may elicit clinical reactions in sensitized individuals; on the contrary, an sensitizing effect is probably minor in pratice.

A cytotoxicity test based on residual protein determination is described and the in vitro toxicity of certain chlorinated aliphatic hydrocarbons is evaluated with this test. The results obtained are sufficiently reproducible to yield an order of cytotoxicity: hexachlorobutadiene is about 100-fold more toxic than chloroform or 1,2-dichloroethane; whereas, 1,1,1-trichloroethane is 10-fold more toxic than these two compounds. The method is fast and lends itself to the toxic evaluation of large numbers of samples.

Nabam (fungicide dithiocarbamate) has been incorporated with the diet of rats during six months (the doses were: 0, 10, 50, 100, 500, 1000 and 2000 ppm). It decreases significantly the hepatic microsomal enzymes activity (aniline hydroxylase and aminopyrine N-demethylase and the liver P 450 content, but the cytochrome b 5 concentration doesn't seem to be modified. The microsomal lipidic and proteic content is only modified with the highest Nabam dose. Several hypotheses may be proposed to explain the Nabam effects: one is the inhibition of the monooxygenases and their biosynthesis repression.

Sprague Dawley rats were fed with yeast (Candida Maltosa) obtained by fermentation of n-Paraffins F.U. grade (C12-C19). The yeast was incorporated in the diet at 7.2, 18.4 and 34.5% by weight. Each diet was isocaloric and isoproteic with the others and with the standard diet. The yeast supplied 20, 50, 80% of the proteins of the diet respectively. 65 rats per sex per group were selected at random from over 1000 rats and assigned to each of the 4 diets for the carcinogenicity study; 57 rats per sex group were selected at random from the same 1000 rats and assigned to each of the 4 diets for the long term study. In long term study the rats were sacrificed at 3, 6, 15 and 24 months. In the carcinogenicity study the animals were kept till less than 10% of the starting number was surviving; the experiment lasted 30 months. Animals dead spontaneously or killed at the end of the trial were autopsied and the main organs fixed for histological examination. Lesions and tumours were classified. Biochemical, haematological and autopsy variations at the times of sacrifice were observed in the long term study. The experiment showed no pathological differences between controls and animals treated with 20 and 50% proteins from yeast. The group fed with 80% single cell protein showed a significant increase of malignant lymphomas incidence.

Impairment of nervous functions has been investigated by clinical and neurophysiological methods in 55 workers exposed to inorganic mercury intoxication and 27 controls living in the same area. A polyneuropathy, mainly of sensory type, has been found in 6 exposed workers (10,9%) and 2 control (7,4%); a mono or multineuropathy of sensory or motor type was present in 15 exposed (27%) and 10 control (29,6%) subjects. Central N.S. involvement has been found in 7 out of 12 exposed workers examined and in 1 out of 7 controls by electronystagmography. Neurological examination demonstrated minor signs of cerebellar type in 3 instances.