Publications by authors named "C H Seckel"

Chloral hydrate (CH) and its metabolites, trichloroacetate (TCA) and dichloroacetate (DCA), have been shown to induce liver tumors in male B6C3F1 mice. The pharmacokinetics of CH and its metabolites play an important role in its toxicity. This study was designed to characterize the kinetics of CH metabolism, and the formation and elimination of TCA, DCA, trichloroethanol (TCOH), and trichloroethanol glucuronide (TCOG) in male B6C3F1 mice.

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Environmental and occupational exposures are typically to mixtures of chemicals, although most toxicity information is for individual compounds. Interactions between chemicals may involve pharmacokinetic and/or pharmacodynamic effects resulting in modulation of toxicity. Therefore, physiologically based pharmacokinetic modeling has been used to analyze data describing the metabolism of vinyl chloride (VC) and trichloroethylene (TCE) mixtures in rats.

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When used in the risk assessment process, the output from physiologically based pharmacokinetic (PBPK) models has usually been considered as an exact estimate of dose, ignoring uncertainties in the parameter values used in the model and their impact on model predictions. We have collected experimental data on the variability of key parameters in a PBPK model for tetrachloroethylene (PCE) and have used Monte Carlo analysis to estimate the resulting variability in the model predictions. Blood/air and tissue/blood partition coefficients and the interanimal variability of these data were determined for tetrachloroethylene (PCE).

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Mice exposed to various chemicals have been shown to respond by decreasing their core body temperature. To examine what effect such a response might have on the determination of in vivo metabolism, core body temperatures of B6C3F1 mice were recorded with temperature telemetry devices during exposure to chloroform (CHCl3) in a closed, recirculating chamber (100 to 5500 ppm). Significant decreases in body temperature occurred in all mice exposed to greater than 100 ppm CHCl3, with the greatest decrease of 14 degrees C occurring at 5500 ppm.

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