A survey of genetic toxicology testing in industry, contract laboratories and government

1984 survey of genetic toxicology testing in industry, government and academic laboratories

Compiled results of the 1984 Genetic Toxicology Association's survey representing a total of 72 responses from governmental, contract, industrial, or academic institutions regarding the status of 32 recognized genetic toxicology assays, were as follows: Most frequently performed on a routine or occasional basis: Ames (76% of all respondents routinely or occasionally perform the assay); in vitro cytogenetics (59%); in vivo Bone Marrow Cytogenetics (56%); in vitro Sister Chromatid Exchange (56%); in vitro Unscheduled DNA Synthesis (43%); Mutation in CHO HGPRT (42%); Micronucleus test (41%); Mutation in L5178Y (36%). Assay associated with in vivo and in vitro chromosomal end points (aberrations, SCE, micronucleus) constituted the major area of increased use since the 1982 survey. Assays of developmental interest included DNAS binding both in vitro and in vivo and UDS in vivo. Quantitative analysis of the data indicated: Industrial and contract laboratories processed the largest volumes of chemicals over the broadest spectrum of assays. Industrial laboratories showed a marked increased since 1982 in testing compounds in-house. The number of assays sponsored by governmental laboratories, both in-house or subcontracted, increased from 1982. Academic institutions ranked lowest in number of compounds examined.

Artificial intelligence and Bayesian decision theory in the prediction of chemical carcinogens

Two procedures for predicting the carcinogenicity of chemicals are described. One of these (CASE) is a self-learning artificial intelligence system that automatically recognizes activating and/or deactivating structural subunits of candidate chemicals and uses this to determine the probability that the test chemical is or is not a carcinogen. If the chemical is predicted to be carcinogen, CASE also projects its probable potency. The second procedure (CPBS) uses Bayesian decision theory to predict the potential carcinogenicity of chemicals based upon the results of batteries of short-term assays. CPBS is useful even if the test results are mixed (i.e. both positive and negative responses are obtained in different genotoxic assays). CPBS can also be used to identify highly predictive as well as cost-effective batteries of assays. For illustrative purposes the ability of CASE and CPBS to predict the carcinogenicity of a carcinogenic and a non-carcinogenic polycyclic aromatic hydrocarbon is shown. The potential for using the two methods in tandem to increase reliability and decrease cost is presented.