University of Vermont

College of Medicine

Department of Pathology and Laboratory Medicine

Bio for Vernon E Walker, DVM, PhD

Vernon E Walker, DVM, PhD

Associate Professor, Research
Department of Pathology


Contact Information
E-mail: Vernon.Walker@uvm.edu
Office Location:
Pathology, 665 Spear St.

Education

1983   DVM, University of Tennesse College of Veterinary Medicine, Knoxville, TN
1983-1984   Resident (Comparative Pathology), Comparative Medicine Department, College of Medicine and Dentistry, University of Alabama at Birmingham, Birmingham, AL
1984-1985   Resident (Veterinary Pathology), Department of Pathology and Parasitology, College of Veterinary Medicine, Auburn University, Auburn, AL
1985-1991   Graduate Fellow, Department of Pathology, Duke University, Durham, NC
1985-1991   Postdoctoral Trainee (Veterinary Pathology), Chemical Industry Institute of Toxicology, Research Triangle Park, NC
1991   PhD (Experimental Pathology), Duke University, Durham, NC
1991-1993   Postdoctoral Fellow (Molecular Genetics), Department of Pathology, School of Medicine, University of North Carolina, Chapel Hill, NC

Research Interests

My research program is focused on the identification and validation of biological markers that are suitable for investigating genotoxic mechanisms, determining human exposures, and evaluating human risks associated with exposure to chemical or physical agents in the environment or as a consequence of medical therapies, activities of military personnel, or bioterrorism.  A major part of my research is concerned with the characterization of the dose effects and genotoxic risks from exposures to several important industrial chemicals and environmental pollutants that are epoxide/epoxide-forming compounds (e.g., acrylonitrile, 1,3-butadiene, and ethylene oxide) known to induce lung cancers in mice.  The long-term goals of these epoxide studies are to define shapes of the dose-response curves for stochastic effects at environmentally relevant exposure levels, to develop mechanistic-based models for describing and predicting patterns of chemically-induced DNA damage and mutations, and to establish cross-species extrapolations between biomarkers in chemical-exposed rodents and humans for more realistic biologically-based risk assessments.  Another aspect of my research is focused on the potential for azidothymidine, and other nucleoside analogue reverse transcriptase inhibitors (NRTIs), to be incorporated into host cell DNA and to act as clastogens or mutagens and mitochondrial toxins in children born to HIV-infected women who received highly active antiretroviral therapy.  Current research is directed toward the development of a new drug-based antiretroviral therapy that both inhibits HIV replication and protects against NRTI-induced DNA damage and health risks.  Additional research is focused on improving the rodent T-cell mutation assay systems and developing novel HPRT and other endogenous gene mutation assays, using organ-specific cell types such as type II pneumocytes, glial cells, hepatocytes, and mammary epithelium to assess the mutagenic and oncogenic potential of suspected human carcinogens with tissue specific tropisms.

Academic Appointments

2009-Present   Associate Professor Research, Department of Pathology, University of Vermont, Burlington, VT
2008-2009   Senior Resarch Scientist, BioMosaics, Inc., Burlington, VT
2001-2008   Clinical Associate Professor, College of Pharmacology, University of New Mexico (UNM), Albequerque, NM

Publications

2010  Torres SM, Scully RE, Lipsitz SR, Miller TL, Sallan SE, Walker VE, Lipshultz SE.  Mutational analysis of the mitochondrial tRNA genes and flanking regions in lymphocytes from long-term pediatric cancer survivors given anthracycline chemotherapy for acute lymphoblastic leukemia. J Clin Oncol, submitted.

2010   Swenberg JA Bordeerat NK, Boysen G, Carro S, Georgieva NI, Nakamura J, Troutman JM, Upton PB, Albertini RJ, Vacek PM, Walker VE, Sram RJ, Goggin M, Tretyakova N.  1,3-Butadiene: Biomarkers and application to risk assessment. Chem-Biol Interact, submitted.

2010   Meng Q, Hackfield LC, Hodge RP, Wisse LA, Redetzke DL, Walker VE.  Mutagenicity of stereochemical configurations of 1,3-butadiene epoxy metabolites. Res Rep Health Eff Inst  150:1-34;discussion 35-41.

2010   Goggin M, Seneviratne U, Swenberg JA, Walker VE, Tretyakova N.  Column switching HPLC-ESI(+)-MS/MS methods for quantitative analysis of exocyclic dA adducts in DNA of laboratory animals exposed to 1,3-butadiene.  Chem Res Toxicol  19:808-812.

2010   Georgieva NI, Boysen G, Bordeerat N, Walker VE, Swenberg JA.  Exposure-response of 1,2:3,4-diepoxybutane specific N-terminal valine adducts in mice and rats after inhalation exposure to 1,3-butadiene.  Toxicol Sci  115:322-329.