Bioassay data

Guilmette RA, Eidson AF. 1992. Using animal dosimetry models to interpret human bioassay data for actinide exposures. J Radioanal Nucl Chem 156(2) 425-449. 

Is the proper comparator data for evaluating performance human or rodent bioassay data It should be kept in mind that there are sets of rodent bioassay... 

Table 7 Attribution of the Real Sewage Sludge Formed on Treatment Plants of Different Cities in Russia to the Classes of Hazard on the Basis of the Bioassay Data...

Based on the correlation matrix of all bioassays data obtained with 37 effluents, it can be concluded that none of the bioassays produces data that are redundant. In other words, all bioassay procedures add to the information content of the PEEP index. 

The mangrove plant Heritiera littoralis (Stercullaceae) has been utlized by natives of the Philippines as a fish poison. The hexane extract of this plant has shown toxicity to fish (Tilapia nllotlca). A novel sesquiterpene which was assigned the name heritianin has been identified as one of the compounds with ichthyotoxicity. The structure elucidation of heritianin and other compounds in the hexane extract of Heritiera littoralis is presented with bioassay data. 

Hagiwara, A., Tanak, H., Imaida, K., Tamano, S., Fukushima, S. Ito, N. (1993) Correlation between medium-term multi-organ carcinogenesis bioassay data and long-term observation results in rats. Jpn. J. Cancer Res., 84, 237-245... 

Special thanks are given to the editors of this book for their invitation to contribute this chapter. The invaluable technical contribution of Manon Harwood, Lucie Menard, Christine Girard and Sylvain Trottier from the St. Lawrence Centre is acknowledged for their conduct of the bioassays. Data on chemistry, toxicity to macro-invertebrates and benthos were kindly provided by the Environmental Protection Branch of Environment Canada (Quebec Region), and BEAK International Incorporated. 

Risk Assessment. The model provides an approach to estimating doses of MEHP to the testes of the rat following oral doses of DEHP and might be useful for internal dose-response assessment of rat bioassay data in which the toxicity end point of interest is testicular toxicity. However, such uses of the model, or other potential uses in risk assessment, have not been evaluated. 

Structures and BioAssay data from MTDP (Molecular Targets Development... 

Contamination (including mycoplasma) and differences in serum lots for cultures can affect bioassay performance. Consequently, it is important to maintain cell lines adequately and use consistent sources of material to ensure reproducibility of test results. Bioassay data generally follow a sigmoidal curve, which can complicate the interpretation of results. 

One obvious application of these databases is to use them as sources of training data when developing predictive models. For example, Novotarskyi et al. (46) employed PubChem Bioassay data to develop models to predict CYP450 1A2 inhibition, and Shen et al. (47) employed the database to develop a support vector... 

Mixture of concern. Mixture assessments based on data on the mixture of concern include direct testing of the environmental mixture itself or its concentrate, or evaluating fractions or single components of the whole mixture. When occupational, epidemiological, or bioassay data are available on the mixture of concern, a toxicological reference value, such as a reference dose (RfD),1 reference concentration (RfC),2 or cancer slope factor,3 can be determined for the whole mixture using similar... 

Recent advances in chemoinformatics have greatly enhanced the utility of these resources and many are now accessible via the Internet.28 CHEMnet-BASE (www.chemnetbase.com) provides online access to a variety of databases including the Dictionary of Natural Products and the Dictionary of Marine Natural Products, although full access through CHEMnetBASE requires a subscription. The Chemical Structure Lookup Service (http //cactus.nci.-nih.gov/lookup) is an open access database and incorporates information from more than 80 databases on over 27 million structures. PubChem (http //pub-chem.ncbi.nlm.nih.gov/) is another open access database that also links bioassay data to each structure. Measures such as the US National Institutes of Health (NIH) Public Access Policy Mandate should increase the amount of openly accessible information available on the Internet and facilitate dissemination of information. 

In practice, animal bioassay data are generally the primary data used in risk assessments. Animal studies are well-controlled with known exposures, and they are carried out with detailed, careful clinical and pathological examinations. The use of laboratory animals to determine potential toxic effects in humans is a necessary and accepted procedure. It is a recognized fact that effects in laboratory animals are usually similar to those observed in humans at comparable dose levels. Exceptions are primarily attributable to differences in the pharmacokinetics and metabolism of the xenobiotics. 

Cancer risk assessment involves two steps. The first step is a qualitative evaluation of all epidemiology studies, animal bioassay data, and biological activity (e.g., mutagenicity). The substance is classified as to the carcinogenic risk to humans based on the weight of evidence. If the evidence is sufficient, the substance may be classified as a definite, probable, or possible human carcinogen. 

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