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Biomedical subjects

J Einhorn

Publications and source records attributed to J Einhorn.

At least 19 recordsLinked to original sources
PubMed1994

Ram sexual pheromone: first approach of chemical identification.

A series of experiments has been designed with the aim of identifying the pheromone of the ram responsible for the primer effect--induction of a LH peak and ovulation--in anoestrous ewes. In a first experiment, the pheromonal activity of various sources was tested, extract of ram fleece and ante orbital gland secretion induced characteristic changes in LH secretion, whereas urine was ineffective. A second experimental series showed that an accurate separation of the ram's fleece extract in acid and neutral fractions resulted in each case in a complete loss of activity whereas both together were efficient, indicating that the pheromonal action involves several components. From GC-MS analysis of both fractions, and after comparison of male and female wool extract, semi-synthetic formulations were tested. The association of synthetic 1,2-hexadecanediol and 1,2-octadecanediol with the natural acid fraction was efficient in stimulating LH release in anoestrous ewes. As the most frequent linear fatty acids have been shown not to be necessary, a role of branched and oxygenated fatty acids has been hypothesised.

Animals↗
PubMed1992

Genotoxic effectivity--comparison of 36 nitrated furan and arenofuran derivatives on a quantitative scale. Statistical comparison of T7 and other short-term tests.

Thirty-six nitrated furan and arenofuran derivatives were measured and quantitatively characterized by the T7 inactivation test. A wide range of substances previously studied allowed us to compare the collected quantitative data with those obtained by other workers using different short-term tests. Based on comparative statistical evaluation of these data a borderline was determined for the genotoxic effect: compounds having in our short-term test mutagenicity index (MI) values smaller than 8.0 are positive while the higher values represent negative genotoxicity. Classification of 36 nitrofuran/nitroarenofuran derivatives is given both on the basis of the quantitative genotoxicity scale and in terms of +/- on the qualitative scale. All but one compound were found to be genotoxic and the genotoxic activities of these compounds were compared with the results of other carcinogenicity or mutagenicity tests.

Carcinogenicity Tests↗