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Biomedical subjects

D W Bleyl

Publications and source records attributed to D W Bleyl.

At least 37 records · Page 2Linked to original sources
PubMed1988

Is the variational scope of individual sensitivity given enough consideration in evaluation of risks caused by toxicological substances in food?

The contemporary concept of evaluation of risks with humans caused by xenobiotics in food is critically reviewed. In this context it is pointed out that epidemiologic studies, in most cases, give little reliable evidence only. Mankind's risk factors are of a multi-dimensional composition, depending on genetic aspects and the differring health and nutrition statuses of the individuals. This leads to an enormously wide scope of variations in the individual sensitivity to xenobiotics. Contemporary knowledge leaves the question open, whether predisposed population groups are always sufficiently protected by the level of the permissible amount of xenobiotics.

Food Contamination↗
PubMed1986

[Comparison of the distribution and toxicity of alpha-, beta-, and gamma-hexachlorocyclohexane (HCH) following 30 days of administration to rats].

Administration of 1000 ppm alpha-HCH, 600 ppm beta-HCH and greater than or equal to 125 ppm gamma-HCH to rats caused a growth retardation. alpha-HCH and beta-HCH led to livermass enlargement. beta-HCH caused a decrease of absolute brain-mass. In case of alpha-HCH and gamma-HCH fat tissue, kidneys and adrenals had a high burden in residues. Fat tissue and adrenals had high residues of beta-HCH. The level of HCH-residues during the test period was gamma much less than beta less than alpha. The results are discussed taking into account the contradictory knowledge from literature.

Animals↗
PubMed1985

[Comparative studies of 2 organic mercury compounds alone or in combination with ethanol following pre- or postnatal application in mice].

Studies on pre- and/or postnatal effects on mice were carried out with their identical exposure (2 mg Hg/kg body mass) to phenyl mercuric acetate or N,N'-bis-(dimethylmercury)-p-toluol-sulphonamide. Parameters of morphology, of residues, and behaviour teratology were taken into consideration. Potentiating combination effects were only observed with behaviour toxicological investigations after prenatal exposure to methylmercury. That concerned the breeding results of the P-generation and the capacity of the F1-generation to learn on the 30th and 31st day p.n. during a swimming test in a labyrinth. Synergistic effects were observed with both the mercury compounds in the swimming test on the 12th day p.n. after pre- as well as postnatal exposure.

Animals↗
PubMed1984

[The influence on reproduction in rats of DDE mobilization induced by ethanol administration during pregnancy and lactation].

The mobilization of xenobiotics is, in common with their persistence and accumulation, a latent problem of our chemicalized society. Possible sequels connected with the chronic consumption of alcohol were demonstrated by results from animal experiments. After a 10-week exposition to DDE (50 p.p.m. given with the diet), followed by a time of nonexposition, rats were mated and their reproductiveness was brought in relation to the results from residue analyses. Half of the animal received 20% alcohol instead of drinking water during pregnancy and lactation. An alcohol-induced increase in the mobilization of DDE was evidenced on determining residues in the maternal brain, the placentae and the foetus, and also by the excretion in milk and urine. There was a significance increase in prenatal and postnatal mortality (reduced survival index). By analogy to DDT, an oestrogenic action is assumed to be causative.

Adipose Tissue↗
PubMed1984

[Modification of maneb toxicity by chronic ethanol intake--prenatal toxicologic studies on a high-risk group].

Rats, dose-dependent on maneb during pregnancy and lactation (20, 110, 200 or 290 ppm maneb in their food) obtained water or 20 percent alcohol to drink. The animals given pure water indicated no effect. Alcohol in combination with the same concentrations of maneb in the food raised embryotoxicity and produced retardation of the skeletons and postnatal growths in the F1-generation. There was dose-dependent coergistic effect in the breeding results from the alcoholic mothers. The practical significance of this over 15-fold higher susceptibility of alcoholic animals is discussed.

Abnormalities, Drug-Induced↗
PubMed1984

[Progress report. Possibilities and limitations of the in vitro technic for prenatal toxicologic studies].

Considering the variety of problems of the prenatal toxicity test the in vitro methods hitherto existing in this field are discussed according to their degree of complexity (cell culture, mass culture of dispersed cells, organ culture, whole embryo culture) within their limitations and possibilities. In this connection special attention is focussed to the use of human tissue for testing basic mechanisms of the developmental biology and for toxicity tests.

Animal Testing Alternatives↗
PubMed1981

[Continuous interpretation system for the cytophotometer "Amplival photometry"=-studies with pesticide combinations].

By means of complementary technique the cytophotometer "Amplival photonetrie" is converted in a continuous interpretation system. Thereby it is possible to move the slides by controlling step motors in alpha- and/or gamma-axis. The number of stepts and the speed of them can be predetermined. For the quantitative histochemical examination the sum of the extinctions of single steps is determined. therefore the arythmetical average can be calculated per arbitrary unit tissue. In examinations with combinations of pesticides the usefulness of the interpretation system is demonstrated.

Animals↗