Mathematical and statistical models are important tools in the design, analysis and interpretation of experiments in toxicology and biochemistry. However, many of the properties of the existing models are poorly understood. In addition, many of the existing models do not adequately describe current research findings in these areas. The goal of this project is to increase our understanding of the use and application of existing models in toxicology and biochemistry and to develop and implement new models to aid in explaining new research findings. One research effort concerns the use of physiologically based pharmacokinetic models in estimating carcinogenic risk from exposure to chemicals. A method was developed for incorporating all the sources of variability into the risk estimation procedure to arrive at an estimate of the overall variability. It was shown that the use of these models was likely to increase the variability of the risk estimates. In another study, the ability of carcinogenicity data to estimate parameters in a clonal two-stage model of carcinogenesis was examined. The findings indicated that the carcinogenicity data was inadequate for this purpose and additional information must be used. Research on this topic is continuing with a focus on redesigning carcinogenicity experiments to provide better information on these model parameters. Other research topics concern correcting for survival differences in animal carcinogenicity data and the potential risks from using inappropriate models in estimating risks of developmental defects from exposure to chemicals.

Agency
National Institute of Health (NIH)
Institute
National Institute of Environmental Health Sciences (NIEHS)
Type
Intramural Research (Z01)
Project #
1Z01ES048002-02
Application #
3918684
Study Section
Project Start
Project End
Budget Start
Budget End
Support Year
2
Fiscal Year
1988
Total Cost
Indirect Cost
Name
U.S. National Inst of Environ Hlth Scis
Department
Type
DUNS #
City
State
Country
United States
Zip Code
Portier, C (2009) 4 Toxicological decision-making on hazards and risks - status quo and way forward: 4.1 current concepts and schemes of science-driven toxicological decision-making - an overview. Hum Exp Toxicol 28:123-5
Prause, Andrea S; Stoffel, Michael H; Portier, Christopher J et al. (2009) Expression and function of 5-HT7 receptors in smooth muscle preparations from equine duodenum, ileum, and pelvic flexure. Res Vet Sci 87:292-9
Schmitz, A; Portier, C J; Thormann, W et al. (2008) Stereoselective biotransformation of ketamine in equine liver and lung microsomes. J Vet Pharmacol Ther 31:446-55
Gohlke, Julia M; Griffith, William C; Faustman, Elaine M (2008) Computational models of ethanol-induced neurodevelopmental toxicity across species: Implications for risk assessment. Birth Defects Res B Dev Reprod Toxicol 83:1-11
Pfeiffer, Julia B R; Mevissen, Meike; Steiner, Adrian et al. (2007) In vitro effects of bethanechol on specimens of intestinal smooth muscle obtained from the duodenum and jejunum of healthy dairy cows. Am J Vet Res 68:313-22
Barton, Hugh A; Chiu, Weihsueh A; Woodrow Setzer, R et al. (2007) Characterizing uncertainty and variability in physiologically based pharmacokinetic models: state of the science and needs for research and implementation. Toxicol Sci 99:395-402
Gohlke, Julia M; Portier, Christopher J (2007) The forest for the trees: a systems approach to human health research. Environ Health Perspect 115:1261-3
Smith, Marjo V; Miller, Chris R; Kohn, Michael et al. (2007) Absolute estimation of initial concentrations of amplicon in a real-time RT-PCR process. BMC Bioinformatics 8:409
Knobloch, M; Portier, C J; Levionnois, O L et al. (2006) Antinociceptive effects, metabolism and disposition of ketamine in ponies under target-controlled drug infusion. Toxicol Appl Pharmacol 216:373-86
Becker, Richard A; Borgert, Christopher J; Webb, Simon et al. (2006) Report of an ISRTP workshop: progress and barriers to incorporating alternative toxicological methods in the U.S. Regul Toxicol Pharmacol 46:18-22

Showing the most recent 10 out of 57 publications