Rodents dominance

Genetic Toxicology Rodent Dominant Lethal Test (Updated Guideline, adopted 4 April 1984)... 

Genetic toxicology Rodent dominant lethal test... 

B.ll Mutagenicity - In vivo mammalian bone-marrow chromosome aberration test B.12 Mutagenicity mammalian erythrocyte micronucleus test B.20 Sex-Unked recessive lethal test in Drosophila melanogaster B.22 Rodent dominant lethal test... 

The rodent dominant lethal test OECD TG 478 US-EPA OPPTS 870.5450 EU Annex V B.22... 

A positive response in the rodent dominant lethal test indicates that the test substance may be genotoxic in the germ cells of the treated sex of the test species as evaluated by an increase in the number of dominant lethals evaluated as the sum of pre- and postimplantation loss. A dominant lethal mutation is one occurring in a germ cell, which does not cause dysfunction of the gamete but which is lethal to the fertilized egg or developing embryo. 

Stodddard solvent was not genotoxic in a variety of assays including Salmonella typhimurium, a mouse lymphoma mutation assay, rodent bone marrow cytogenic tests, and rodent dominant lethal tests." ... 

Ashby, J. Clapp, M.J.L. (1995) The rodent dominant lethal assay a proposed format for data presentation that alerts to psendo-dominant lethal effects. Mutat. Res., 330, 209-218 Ashby, J., Brady, A., Elcombe, C.R., Elliott, B.M., Ishmael, J., Odnm, J., Tngwood, J.D., Kettle, S. Purchase, IF. (1994) Mechanistically-based human hazard assessment of peroxisome proliferator-induced hepatocarcinogenesis. Hum. exp. Toxicol., 13 (Suppl. 2), S1-S117... 

OPPTS Harmonized/870 Health Effects Test G uidelines/Series/870-6300.pdf EPA (U.S. Environmental Protection Agency). 1998d. Health Effects Test Guidelines OPPTS 870.5450 Rodent Dominant Lethal Assay. EPA 712-C-98-227. Office of Prevention, Pesticides and Toxic Substances, U.S. Environmental Protection Agency. [Online]. 

Rodent dominant lethal mutation test (OECD 478)... 

OECD (1984). Genetic toxicology Rodent dominant lethal test. OECD Guideline for the Testing of Chemicals 478, 1-6. 

Rodent-dominant lethal test Germinal tissue of rodent Chromosome aberrations and/or gene mutations in germinal tissue B22/TG 478... 

Laboratory experiments using rodents, or the use of gas analysis, tend to be confused by the dominant variable of fuel—air ratio as well as important effects of burning configuration, heat input, equipment design, and toxicity criteria used, ie, death vs incapacitation, time to death, lethal concentration, etc (154,155). Some comparisons of polyurethane foam combustion toxicity with and without phosphoms flame retardants show no consistent positive or negative effect. Moreover, data from small-scale tests have doubtful relevance to real fine ha2ards. 

Mouse visible or eleetrophoretie specifie-locus tests Assays for skeletal and cataract mutations Cytogenetic analy.sis and heritable translocation assays DNA damage and repair in rodent germ cells Dominant lethal assay... 

Abstract For most mammals, the ability to detect odours and discriminate between them is necessary for survival. Information regarding the availability of food, the presence of predators and the sex, age and dominance status of conspecifics is odour mediated. Probably because of this extraordinary reliance upon odour cues, mice and rats have developed the ability to learn and remember information associated with olfactory cues as effectively as primates recall visually related cues. As a result, these rodents have become the model of choice to study the neural and cognitive processes involved in olfactory discrimination. In this paper, we describe some of the more ethologically based tasks used in assessing olfactory discrimination and the advantages and disadvantages of the different methodologies employed. 

The glutathione 5-transferase pathway is sometimes in biochemical competition with the epoxide hydratase pathway, in that both deactivate intermediates of the MMFO. Epoxide hydratase is a microsomal enzyme that acts specifically to deactivate epoxide intermediates, by the addition of water across the C—O bond to form a diol. As a very broad generality, the glutathione 5-transferase pathway tends to be more prominent in rodents, while the epoxide hydratase pathway tends to be more dominant in nonrodents. 

In other rodents, subordinate males also smell scent marks quite often and so keep informed on the presence, status and activities of higher-ranking group members. For instance, dominant males of the hispid cotton rat, Sigmodon hispidus, urine mark more than subordinates. The social status of the male urine donor affects the response of other males to the odor. The response of a reproductive female to feces of either sex depends on her dominance status (Gregory and Cameron, 1989). 

Animal health is a segment of the life sciences industry at the interface of pharmaceuticals and agrochemicals. Global sales were 15 billion in 2005 ( 14.5 billion in 2004, 13.8 billion in 2001, inflation-adjusted). Of the top 10 companies, 9 are business units or spinoffs from pharmaceutical companies (see Table 11.9). The industry is rather concentrated, with the top 10 companies accounting for 75% of total sales. As they do in pharma, US companies dominate in animal health products. Many of the veterinary products in the portfolios had originally been developed for human use or as pesticides. In the pet (respectively companion animal) segment, which comprises cats, dogs, birds, some rodents, reptiles, and horses and represents about 40% of the total market, the association with human health is particularly prominent. 

In rodents treated in vivo, acrylonitrile did not induce unscheduled DNA synthesis in hepatocytes or spermatocytes of rats, chromosomal aberrations in the bone marrow of mice or rats, chromosomal aberrations in spermatogonia of mice, micronuclei in the bone marrow of mice, or dominant lethal effects in either rats or mice. Sister chromatid exchanges were, however, induced in mouse bone marrow. 

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