Hamster dominance

In vivo, neither covalent binding to DNA nor DNA strand breakage was induced in several studies on rat liver, and unscheduled DNA s mthesis was not induced in the liver of either rats or mice. Gene mutations were not induced in the liver of dosed mice in a single study and there was no evidence for induction of chromosomal aberrations in mice or rats. Aberrations were induced, however, in the embryos of dosed pregnant Syrian hamsters. Dominant lethal effects were reported to be induced in male mice, but re-evaluation of these data did not confirm this conclusion. 

Protein-protein interactions between heterodimeric protein pairs that form only transient interactions can be detected, y-secre-tase is presenilin-1 (PS1) dependent [51-53]. PS1 is a 467-amino acid, 9-transmembrane domain protein. Over 100 documented single point mutations are known to cause autosomal-dominant familial AD (FAD) [54], in which the ratio of the more fibrilogenic variety of A ft (A/142) to the less fibrilogenic variety (A/140) is increased. Chinese hamster ovary (CHO) cells were stably transfected with human APP and either wild type or mutant PS1 [4, 55]. 

In the golden hamster, M. auratus, both dominant and subordinate males use the flank glands to communicate their social status to inhibit overt aggression during encounters (Ferris etal., 1987). However, they do not need their flank glands to develop dominant/subordinate relationships. 

The function of the flank gland of the golden hamster, Mesocricetus auratus, is not clear but it appears to be involved in signals of sexual and social status and familiarity of the male to the female. Sexually receptive females spend more time near flank scent marks of intact males than castrates, or clean controls. They also stay longer near marks from familiar males than novel males. Finally, these females spend more time near marks of dominant males (compared with subordinate males) (Montgomery-St. Laurent etal, 1988). 

Ferris, C. G., Axelson, J. F., Shinto, L. H., and Albers, H. E. (1987). Scent marking and the maintenance of dominant subordinate status in male golden hamsters. Physiological... 

A number of genotoxic effects have been reported for 1,3-DCP including increased DNA strand breaks, sister chromatid exchanges, and mitotic aberrations in Chinese hamster cells. " It did not induce dominant lethal mutations in the germ cells of male CD rats after inhalation of 150ppm."... 

DNA adducts, dominant lethal mutations, and gene mutations in mice chromosomal aberrations and sister chromatid exchanges in Chinese hamsters and mice and micronuclei in splenocytes and spermatids of rats and mice. ... 

In an in vivo experiment in rats, HCB did not induce dominant lethal mutations. Chromosomal aberrations were not induced in cultured Chinese hamster ovary cells, nor were mutations induced in bacteria. " HCB does not appear to be genotoxic. 

Mieronueleus formation, B6C3F i mouse erythroeytes in vivo Chromosomal aberrations, Fiseher 344 rat bone marrow in vivo Chromosomal aberrations, Syrian hamster embryos in vivo Dominant lethal test, ICR Swiss miee in vivo Dominant lethal test, miee in vivo [strain not speeified] Dominant lethal test, ICR Swiss miee in vivo Aneuploidy, Fiseher 344 rat hepatoeytes in vivo... 

Phenyl glycidyl ether induced mutations in bacteria and transformation in mammalian cells in vitro (in a Syrian hamster embryo cell clonal assay and in an assay for the enhancement of viral transformation), but did not induce chromosomal aberrations in animal cells in vitro or either micronuclei or chromosomal aberrations in vivo. It did not induce dominant lethal effects in rats (IARC, 1989). 

When tested in the Salmonella assay, acrolein was weakly positive. It was not mutagenic in the dominant lethal assay in the mouse and in the Drosophila sex-linked recessive lethal test, and negative for chromosome aberrations when tested in cultured Chinese hamster ovary cells however, there was an increase in the frequency of sister-chromatid exchanges. 

Mutagenicity tests with and without metabolic activation have been negative. Testing included Salmonella typhimurium assays, testing in Bacillus sub-tilis, and testing in V79 Chinese hamster cells. In addition, bone marrow evaluated after oral exposure was not reported to contain chromosomal damage. It was not reported to cause dominant lethal mutations in mice at 100 mg kg day... 

Ethanol is negative in mutagenicity assays in bacteria, mouse sperm, cell transformation in hamster and rat embryo cells, and chromosome aberrations in vitro. It produces dominant lethal effects in rats and increases sister chromosome exchange in vitro in human and nonhuman lymphocytes. 

McClean, S., Hosking, L.K. and Hill, B.T. (1993) Dominant expression of multiple drug resistance after in vitro X-irradiation exposure in intraspecific Chinese hamster ovary hybrid cells. Journal of the National Cancer Institute, 85, 48—53. 

Amoebtasis - Little new has appeared in this area during the past two years. Several reviews, essentially clinical, have been published. Efforts continue primarily with other nitroimidazoles to achieve superiority to metronidazole. Tinidazole (lO) is receiving substantial favorable attention. Novel bls-anadines of 2,6-diaminoanthraquinone related to 11 have shown activity comparable to the activity of metronidazole against E. histolytica cecal infections tfi rats and hepatic infections, in hamsters. The compounds were nonmutagenic in the Ames and dominant lethal tests. 

The genotoxicity of PCBs has been tested in in vivo and in vitro studies with generally negative results. End points that have been examined in these studies include gene mutations in bacteria and Chinese hamster V79 cells, chromosomal aberrations in human lymphocytes and rat and mouse bone marrow cells and spermatogonia, micronuclei in mouse bone marrow cells, and dominant lethal mutations in rat sperm cells. 

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