Environmental Factor, May 2007, National Institute of Environmental Health Sciences
Frontiers in Environmental Sciences Lecture Series Update
By Eddy Ball
The Frontiers in Environmental Science Lecture Series continued in April with RTP area scientists sharing results of their recent research with scientists at NIEHS. March closed with a lecture by Geneticist Fernando Pardo-Manuel de Villena, Ph.D. Lectures in April included talks on the mechanisms of carcinogenesis by Experimental Pathologist William K. Kaufmann, Ph.D., Neurophysiologist David Armstrong, Ph.D., and Pathologist James Swenberg, D.V.M., Ph.D. As web casts of the lectures become available, they will be posted on the Frontiers in Environmental Science website.
March 30: "On the Origin of the Laboratory Mouse: Lessons from the NIEHS Resequencing Project" by Fernando Pardo-Manuel de Villena, Ph.D. Hosted by William Schrader, Ph.D.
Fernando Pardo-Manuel de Villena is an assistant professor of cancer genetics at the UNC-CH Lineberger Comprehensive Cancer Center. His laboratory is interested in the study of nonrandom segregation of chromosomes during meiosis in mammals, and he is a pioneer in utilizing the results of the NIEHS Mouse Genome Resequencing Project.
Analysis of the project's copious data revealed a significant degree of variation in the laboratory mouse, leading to the realization that different families of the genus Mus can be as different from each other as humans are from chimpanzees. His research, which has been submitted for publication, convinced Pardo-Manuel de Villena that researchers still do not have a good mouse population to use.
April 6:"Mechanisms of Human Environmental Carcinogenesis" by William Kaufmann, Ph.D. Hosted by Christopher Portier, Ph.D.
William Kaufmann is a researcher in the Laboratory of Human DNA Metabolism in the Department of Pathology at the University of North Carolina. His main interest relates to the manner in which cell cycle checkpoints suppress chromosomal instability.
Kaufmann used his findings in research on melanoma as the model for the ways human environmental carcinogenesis modifies checkpoints' suppression of chromosomal instability. He has also been able to pinpoint markers of early stage carcinogenesis that may help clinicians intervene more successfully. Melanoma is an especially fruitful tumor to study, according to Kaufmann, because it is possibly the most prevalent and directly lethal of any of the recognized environmental diseases, killing some 7,000 individuals each year.
April 13: "Thyroid Hormone Signaling and the Implications of Its Disruption for Human Health" by David Armstrong, Ph.D. Hosted by Christopher Portier, Ph.D.
Principal Investigator David Armstrong serves as acting chief of the NIEHS Laboratory of Neurobiology. He and his colleagues in the Membrane Signaling Group investigate the signal transduction pathways that regulate the activity of voltage-gated calcium and potassium channels in the mammalian neuroendocrine system.
His lecture focused on thyroid hormone, which is essential for normal development and metabolism of many human tissues including the brain. When thyroid hormone production or signaling is disrupted during development, the implications can be severe, including deafness, growth retardation and reductions in cognitive ability. According to Armstrong, the basic molecular mechanisms responsible for thyroid hormone's effects on brain development are not completely understood.
April 20: "The Use of Biomarkers to Inform Mechanisms of Carcinogenesis and Risk Assessment" by James Swenberg, D.V.M., Ph.D. Hosted by John Pritchard, Ph.D.
James Swenberg is the Kenan Distinguished Professor of Environmental Sciences and Engineering and faculty director of the UNC-CH Lineberger Comprehensive Cancer Center. He is interested in the role of DNA damage and repair in toxicity, carcinogenesis and risk assessment, including damage arising from direct interaction of chemicals or their metabolites and indirect damage arising from oxidative stress.
His talk focused on results of experiments with ultra-sensitive and highly specific mass spectrometry methods for measuring the DNA and hemoglobin adducts of vinyl chloride and 1,3 butadiene. He has found that identical DNA adducts are caused by lipid peroxidation. Among other findings, he has determined that low exposures to vinyl chloride, such as are found in occupational settings (0.1 ppm), were associated with only a 5% increase over the endogenous levels.