John W Nichols

Summary

Affiliation: U.S. Environmental Protection Agency
Country: USA

Publications

  1. ncbi request reprint A physiologically based toxicokinetic model for dietary uptake of hydrophobic organic compounds by fish: II. simulation of chronic exposure scenarios
    John W Nichols
    Mid Continent Ecology Division, National Health and Environmental Effects Research Laboratory, Office of Research and Development, U S Environmental Protection Agency, Duluth, Minnesota, 55804, USA
    Toxicol Sci 77:219-29. 2004
  2. doi request reprint Toward improved models for predicting bioconcentration of well-metabolized compounds by rainbow trout using measured rates of in vitro intrinsic clearance
    John W Nichols
    US Environmental Protection Agency, Office of Research and Development, National Health and Environmental Effects Research Laboratory, Mid Continent Ecology Division, Duluth, Minnesota, USA
    Environ Toxicol Chem 32:1611-22. 2013
  3. ncbi request reprint Dietary uptake kinetics of 2,2',5,5'-tetrachlorobiphenyl in rainbow trout
    J W Nichols
    U S Environmental Protection Agency, Office of Research and Development, National Health and Environmental Effects Research Laboratory, Mid Continent Ecology Division, Duluth, Minnesota 55804, USA
    Drug Metab Dispos 29:1013-22. 2001
  4. ncbi request reprint In vitro-in vivo extrapolation of quantitative hepatic biotransformation data for fish. II. Modeled effects on chemical bioaccumulation
    John W Nichols
    U S Environmental Protection Agency, Office of Research and Development, National Health and Environmental Effects Research Laboratory, Mid Continent Ecology Division, 6201 Congdon Boulevard, Duluth, Minnesota 55804, USA
    Environ Toxicol Chem 26:1304-19. 2007
  5. doi request reprint Bioaccumulation assessment using predictive approaches
    John W Nichols
    US Environmental Protection Agency, Office of Research and Development, National Health and Environmental Effects Research Laboratory, Mid Continent Ecology Division, 6201 Congdon Boulevard, Duluth, Minnesota 55804, USA
    Integr Environ Assess Manag 5:577-97. 2009
  6. ncbi request reprint In vitro-in vivo extrapolation of quantitative hepatic biotransformation data for fish. I. A review of methods, and strategies for incorporating intrinsic clearance estimates into chemical kinetic models
    John W Nichols
    U S Environmental Protection Agency, Office of Research and Development, National Health and Environmental Effects Research Laboratory, Mid Continent Ecology Division, Duluth, MN 55804, USA
    Aquat Toxicol 78:74-90. 2006
  7. doi request reprint Optimization of an isolated perfused rainbow trout liver model: Clearance studies with 7-ethoxycoumarin
    John W Nichols
    National Health and Environmental Effects Research Laboratory, Mid Continent Ecology Division, Duluth, MN 55804, USA
    Aquat Toxicol 95:182-94. 2009
  8. ncbi request reprint Bioenergetics-based modeling of individual PCB congeners in nestling tree swallows from two contaminated sites on the upper Hudson River, New York
    John W Nichols
    US Environmental Protection Agency, National Health and Environmental Effects Research Laboratory, Mid Continent Ecology Division, Duluth, Minnesota 55804, USA
    Environ Sci Technol 38:6234-9. 2004
  9. doi request reprint A physiologically based toxicokinetic model for methylmercury in female American kestrels
    John W Nichols
    U S Environmental Protection Agency, Office of Research and Development, Mid Continent Ecology Division, 6201 Congdon Boulevard, Duluth, Minnesota 55804, USA
    Environ Toxicol Chem 29:1854-67. 2010
  10. doi request reprint Predicting chemical impacts on vertebrate endocrine systems
    John W Nichols
    U S Environmental Protection Agency, Duluth, Minnesota, USA
    Environ Toxicol Chem 30:39-51. 2011

Detail Information

Publications23

  1. ncbi request reprint A physiologically based toxicokinetic model for dietary uptake of hydrophobic organic compounds by fish: II. simulation of chronic exposure scenarios
    John W Nichols
    Mid Continent Ecology Division, National Health and Environmental Effects Research Laboratory, Office of Research and Development, U S Environmental Protection Agency, Duluth, Minnesota, 55804, USA
    Toxicol Sci 77:219-29. 2004
    ..Relatively low rates of metabolism or growth were shown to have a substantial impact on steady-state biomagnification of chemical residues...
  2. doi request reprint Toward improved models for predicting bioconcentration of well-metabolized compounds by rainbow trout using measured rates of in vitro intrinsic clearance
    John W Nichols
    US Environmental Protection Agency, Office of Research and Development, National Health and Environmental Effects Research Laboratory, Mid Continent Ecology Division, Duluth, Minnesota, USA
    Environ Toxicol Chem 32:1611-22. 2013
    ..The results of a restricted sensitivity analysis highlight critical research needs and provide guidance on the use of in vitro biotransformation data in a tiered approach to bioaccumulation assessment...
  3. ncbi request reprint Dietary uptake kinetics of 2,2',5,5'-tetrachlorobiphenyl in rainbow trout
    J W Nichols
    U S Environmental Protection Agency, Office of Research and Development, National Health and Environmental Effects Research Laboratory, Mid Continent Ecology Division, Duluth, Minnesota 55804, USA
    Drug Metab Dispos 29:1013-22. 2001
    ..Generally, however, metabolism had little or no impact on the uptake, distribution or elimination of TCB. Measured assimilation efficiencies exceeded 90% and are the highest ever reported in fish feeding studies with TCB...
  4. ncbi request reprint In vitro-in vivo extrapolation of quantitative hepatic biotransformation data for fish. II. Modeled effects on chemical bioaccumulation
    John W Nichols
    U S Environmental Protection Agency, Office of Research and Development, National Health and Environmental Effects Research Laboratory, Mid Continent Ecology Division, 6201 Congdon Boulevard, Duluth, Minnesota 55804, USA
    Environ Toxicol Chem 26:1304-19. 2007
    ....
  5. doi request reprint Bioaccumulation assessment using predictive approaches
    John W Nichols
    US Environmental Protection Agency, Office of Research and Development, National Health and Environmental Effects Research Laboratory, Mid Continent Ecology Division, 6201 Congdon Boulevard, Duluth, Minnesota 55804, USA
    Integr Environ Assess Manag 5:577-97. 2009
    ..To implement this strategy it is important to understand the "domain of applicability" of both in vitro and structure-based approaches, and the context in which they are applied...
  6. ncbi request reprint In vitro-in vivo extrapolation of quantitative hepatic biotransformation data for fish. I. A review of methods, and strategies for incorporating intrinsic clearance estimates into chemical kinetic models
    John W Nichols
    U S Environmental Protection Agency, Office of Research and Development, National Health and Environmental Effects Research Laboratory, Mid Continent Ecology Division, Duluth, MN 55804, USA
    Aquat Toxicol 78:74-90. 2006
    ..Unlike most compartmental models, PBTK models are developed to describe the effects of metabolism in the tissue where it occurs. In addition, PBTK models are well suited to modeling metabolism in more than one tissue...
  7. doi request reprint Optimization of an isolated perfused rainbow trout liver model: Clearance studies with 7-ethoxycoumarin
    John W Nichols
    National Health and Environmental Effects Research Laboratory, Mid Continent Ecology Division, Duluth, MN 55804, USA
    Aquat Toxicol 95:182-94. 2009
    ..The extended viability of isolated trout livers achieved in this study creates new opportunities for research on hepatic function in fish...
  8. ncbi request reprint Bioenergetics-based modeling of individual PCB congeners in nestling tree swallows from two contaminated sites on the upper Hudson River, New York
    John W Nichols
    US Environmental Protection Agency, National Health and Environmental Effects Research Laboratory, Mid Continent Ecology Division, Duluth, Minnesota 55804, USA
    Environ Sci Technol 38:6234-9. 2004
    ..Together, these studies establish a quantitative linkage between nestling tree swallows and the insects that they consume and provide strong support for the use of nestling swallows as a biomonitoring species for exposure assessment...
  9. doi request reprint A physiologically based toxicokinetic model for methylmercury in female American kestrels
    John W Nichols
    U S Environmental Protection Agency, Office of Research and Development, Mid Continent Ecology Division, 6201 Congdon Boulevard, Duluth, Minnesota 55804, USA
    Environ Toxicol Chem 29:1854-67. 2010
    ..Alternatively, when combined with a bioenergetics-based description, the model could be used to simulate CH(3)Hg kinetics in a long-term environmental exposure...
  10. doi request reprint Predicting chemical impacts on vertebrate endocrine systems
    John W Nichols
    U S Environmental Protection Agency, Duluth, Minnesota, USA
    Environ Toxicol Chem 30:39-51. 2011
    ..S. Environmental Protection Agency's Endocrine Disruptor Screening Program could be used to assess the potential for accommodation and recovery and inform the development of mechanistically based models...
  11. ncbi request reprint A physiologically based toxicokinetic model for dietary uptake of hydrophobic organic compounds by fish: I. Feeding studies with 2,2',5,5'-tetrachlorobiphenyl
    John W Nichols
    Mid Continent Ecology Division, National Health and Environmental Effects Research Laboratory, Office of Research and Development, U S Environmental Protection Agency, Duluth, Minnesota, 55804, USA
    Toxicol Sci 77:206-18. 2004
    ..It is concluded, however, that a kinetic limitation acting along the entire length of the GI tract resulted in a chemical disequilibrium between feces and tissues of the lower intestine...
  12. ncbi request reprint Use of online microdialysis sampling to determine the in vivo rate of phenol glucuronidation in rainbow trout
    John W Nichols
    U S Environmental Protection Agency, Midcontinent Ecology Division, 6201 Congdon Boulevard, Duluth, MN 55804, USA
    Drug Metab Dispos 36:1406-13. 2008
    ..049/h, which was about 7% of the total rate of PH elimination. This study demonstrates the utility of quantitative MD sampling for kinetic studies of xenobiotic metabolism in fish...
  13. doi request reprint Kinetics and effects of dichloroacetic acid in rainbow trout
    Patrick N Fitzsimmons
    U S Environmental Protection Agency, Office of Research and Development, National Health and Environmental Effects Research Laboratory, Mid Continent Ecology Division, 6201 Congdon Boulevard, Duluth, MN 55804, USA
    Aquat Toxicol 94:186-94. 2009
    ..Observed effects on blood lactate are probably due to the inhibition of pyruvate dehydrogenase kinase in aerobic tissues and may require the participation of a monocarboxylase transport protein to move DCA across cell membranes...
  14. ncbi request reprint Tissue distribution and metabolism of benzo[a]pyrene in embryonic and larval medaka (Oryzias latipes)
    Michael W Hornung
    US Environmental Protection Agency, Office of Research and Development, National Health and Environmental Effects Research Laboratory, Mid Continent Ecology Division, Duluth, MN 55804, USA
    Toxicol Sci 100:393-405. 2007
    ..It remains unclear whether metabolism of BaP in medaka embryos leads to the formation of DNA adducts associated with genotoxic effects or yields metabolites that later lead to other toxicity in juveniles or adults...
  15. ncbi request reprint A compilation of in vitro rate and affinity values for xenobiotic biotransformation in fish, measured under physiological conditions
    Patrick N Fitzsimmons
    U S Environmental Protection Agency, Office of Research and Development, National Health and Environmental Effects Research Laboratory, Mid Continent Ecology Division, 6201 Congdon Boulevard, Duluth, Minnesota 55804, USA
    Comp Biochem Physiol C Toxicol Pharmacol 145:485-506. 2007
    ..Limited data suggest that Vmax and Km for the same reaction may vary by up to three orders of magnitude among species...
  16. doi request reprint Adverse outcome pathways: a conceptual framework to support ecotoxicology research and risk assessment
    Gerald T Ankley
    U S Environmental Protection Agency, Office of Research and Development, National Health and Environmental Effects Research Laboratory, Mid Continent Ecology Division, Duluth, Minnesota 55804, USA
    Environ Toxicol Chem 29:730-41. 2010
    ..In the concluding sections of the paper, we discuss how AOPs can help to guide research that supports chemical risk assessments and advocate for the incorporation of this approach into a broader systems biology framework...
  17. ncbi request reprint Use of multi-photon laser-scanning microscopy to describe the distribution of xenobiotic chemicals in fish early life stages
    Michael W Hornung
    US Environmental Protection Agency, Office of Research and Development, National Health and Environmental Effects Research Laboratory, Mid Continent Ecology Division, 6201 Congdon Blvd, 55804 Duluth, MN, USA
    Aquat Toxicol 67:1-11. 2004
    ..After hatch, once the gastrointestinal tract was completely developed, most of the fluorescent signal was cleared. The MPLSM is a useful tool to describe the tissue distribution of fluorescent PBTs during fish ELS...
  18. ncbi request reprint Quantification of phenol, phenyl glucuronide, and phenyl sulfate in blood of unanesthetized rainbow trout by online microdialysis sampling
    John W Nichols
    U S Environmental Protection Agency, Office of Research and Development, National Health and Environmental Effects Research Laboratory, Mid Continent Ecology Division, 6201 Congdon Boulevard, Duluth, Minnesota, 55804
    Toxicol Mech Methods 18:405-12. 2008
    ..The methods described in this study can be used to collect kinetic data sets of high temporal resolution while eliminating artifacts often associated with conventional blood sampling methods...
  19. doi request reprint Optimizing the use of rainbow trout hepatocytes for bioaccumulation assessments with fish
    Kellie A Fay
    Division of Mid Continent Ecology, US Environmental Protection Agency US EPA, ORD, NHEERL, Duluth, MN, USA
    Xenobiotica 44:345-51. 2014
    ..Hepatocellularity values did not differ by sex. 4. These results suggest that hepatocytes from male and female juvenile trout may be used interchangeably for in vitro-in vivo metabolism extrapolations...
  20. doi request reprint Hepatic clearance of 6 polycyclic aromatic hydrocarbons by isolated perfused trout livers: prediction from in vitro clearance by liver S9 fractions
    John W Nichols
    U S Environmental Protection Agency, National Health and Environmental Effects Research Laboratory, Mid Continent Ecology Division, Duluth, Minnesota 55804
    Toxicol Sci 136:359-72. 2013
    ..These findings provide qualified support for procedures currently being used to predict metabolism impacts on chemical accumulation by fish based on measured rates of in vitro activity. ..
  21. ncbi request reprint Partial life-cycle toxicity and bioconcentration modeling of perfluorooctanesulfonate in the northern leopard frog (Rana pipiens)
    Gerald T Ankley
    US Environmental Protection Agency, Office of Research and Development, National Health and Environmental Effects Research Laboratory, Mid Continent Ecology Division, Duluth, Minnesota 55804, USA
    Environ Toxicol Chem 23:2745-55. 2004
    ..Overall, our studies suggest that R. pipiens is not exceptionally sensitive to PFOS in terms of either direct toxicity or bioconcentration potential of the chemical...
  22. ncbi request reprint Branchial elimination of superhydrophobic organic compounds by rainbow trout (Oncorhynchus mykiss)
    P N Fitzsimmons
    US Environmental Protection Agency, National Health and Environmental Effects Research Laboratory, Mid-Continent Ecology Division, 6201 Congdon Blvd, Duluth, MN 55804, USA
    Aquat Toxicol 55:23-34. 2001
    ..73 log K(ow)) x 0.16)+0.84]...
  23. ncbi request reprint Accumulation of PCB congeners in nestling tree swallows (Tachycineta bicolor) on the Hudson River, New York
    Kathy R Echols
    US Geological Survey, Columbia Environmental Research Center, Columbia, Missouri 65201, USA
    Environ Sci Technol 38:6240-6. 2004
    ..The rate constants were comparable between the two study areas and may be used to predict nestling contamination at other locations. Our studies confirm the utility of nestling tree swallows to evaluate localized PCB contamination...