The recent surge of interest in designing, validating, and implementing short-term tests for carcinogens has been spurred by the fairly convincing correlation be tween the carcinogenicity and mutagenicity of chemicals and physical agents and by the assumption that DNA alteration, mutations, and chromosome aberrations are somehow involved in neoplastic transformation. Moreover, it has been tacitly assumed that the mutagenic capacity alone of compounds would induce regulatory agencies to pass rules for their removal from the environment and would lead the public to avoid them. The actual response, however, is quite different. Governmental departments shy away from making any decisions on the basis of in vitro test systems. The public at large is becoming irritated by daily an nouncements that many of their cherished habits could adversely affect their health. Industry appears to feel threatened and may reduce its search for new beneficial chemicals. The reluctance to accept wholeheartedly the mutagenicity tests for the detection of carcinogens is partly due to uncertainty about the in volvement of mutations in neoplastic transformation, partly due to the present difficulty of extrapolating results from various endpoints obtained on numerous organisms to man, and partly due to a multitude of complex events that lead in vivo to the evolvement of benign or malignant tumors.The ad-3A and ad-3B loci are about 0.1 map units with the nic-2 locus some 5 to 8 map units distal. ... In a negative dikaryon test, no small dense colonies are found in 500 to 1000 colonies scanned. ... Tester Strains Used in Heterokaryon Tests To Determine Genotype of ad-3 Mutants Strain number Genotype 74A-Y68- M13anbsp;...
|Title||:||Short-Term Tests for Chemical Carcinogens|
|Author||:||H.F. Stich, R.H.C. San|
|Publisher||:||Springer Science & Business Media - 2012-12-06|