Chemical structure indexing of toxicity data on the internet: moving toward a flat world.

Standardized chemical structure annotation of public toxicity databases and information resources is playing an increasingly important role in the 'flattening' and integration of diverse sets of biological activity data on the Internet. This review discusses public initiatives that are accelerating the pace of this transformation, with particular reference to toxicology-related chemical information. Chemical content annotators, structure locator services, large structure/data aggregator web sites, structure browsers, International Union of Pure and Applied Chemistry (IUPAC) International Chemical Identifier (InChI) codes, toxicity data models and public chemical/biological activity profiling initiatives are all playing a role in overcoming barriers to the integration of toxicity data, and are bringing researchers closer to the reality of a mineable chemical Semantic Web.

Supplement to the Carcinogenic Potency Database (CPDB): results of animal bioassays published in the general literature through 1997 and by the National Toxicology Program in 1997-1998.

The Carcinogenic Potency Database (CPDB) is a systematic and unifying resource that standardizes the results of chronic, long-term animal cancer tests which have been conducted since the 1950s. The analyses include sufficient information on each experiment to permit research into many areas of carcinogenesis. Both qualitative and quantitative information is reported on positive and negative experiments that meet a set of inclusion criteria.

Bromoethane, chloroethane and ethylene oxide induced uterine neoplasms in B6C3F1 mice from 2-year NTP inhalation bioassays: pathology and incidence data revisited.

Chloroethane, bromoethane and ethylene oxide represent a unique set of chemicals that induce endometrial neoplasms in the uterus of B6C3F1 mice following an inhalation route of exposure. The results of the NTP's chronic bioassays with these three compounds resulted in an unusually high incidence of uterine epithelial neoplasms in B6C3F1 mice (chloroethane 86%, bromoethane 56%) and a lower incidence for ethylene oxide (10%). The uterine neoplasms were classified as adenomas, adenocarcinomas, and squamous cell carcinomas for bromoethane, and as adenocarcinomas for both chloroethane and ethylene oxide.

Comparison of cancer risk estimates based on a variety of risk assessment methodologies.

The EPA guidelines recommend a benchmark dose as a point of departure (PoD) for low-dose cancer risk assessment. Generally the PoD is the lower 95% confidence limit on the dose estimated to produce an extra lifetime cancer risk of 10% (LTD(10)). Due to the relatively narrow range of doses in two-year bioassays and the limited range of statistically significant tumor incidence rates, the estimate of the LTD(10) is constrained to a relatively narrow range of values.