|
Dr. Joseph Bressler is a research scientist at Kennedy Krieger Institute and is also an associate professor of Environmental Health Sciences at the Bloomberg School of Public Health at Johns Hopkins University.
Biographical Sketch:
Dr. Bressler received his B.S. degree in biology from the State University of New York at Stony Brook in 1973 and his Ph.D. degree in physiology from Rutgers University in 1978. His postdoctoral training at UCLA was in neurosciences, where he studied the involvement of glial cells in response to toxic agents. After his postdoctoral training, Dr. Bressler continued his studies on glial cells at the National Institutes of Health, Bethesda, MD. Dr. Bressler has been a research scientist at the Kennedy Krieger Institute since 1988 where he has focused his studies to the effects of lead (Pb) on glial cells as well as other types of cells in the central nervous system. He also directs the Trace Metals Laboratory, which is responsible for measuring lead in samples in biological fluids and the environment.
Research Summary:
Tight barriers such as those expressed by epithelial cells lining the intestine or kidney tubules, or by endothelial cells in the brain, restrict the transport of charged chemical or chemicals with high molecular weight. These chemicals may include ions and hormones or pollutants in the environment. The anatomical basis of the tight barrier is tight junctions that fuse the cells together thereby preventing chemicals from passing between cells. Because tight barriers would also slow the transport of needed nutrients, cells forming tight barriers express specific transporters.
Our laboratory has been studying transporters and their interaction with environmental toxicants. We found, for example, that an iron transporter mediates the uptake of toxic metals such as lead and cadmium. Additionally, trivalent metals such as aluminum and lanthanum activate iron transporters and also increase the transport of toxic metals. Further characterization of iron transporters and their involvement in lead poisoning is underway in our laboratory. We have also been studying toxicants that disrupt tight barriers such as the blood brain barrier (BBB). For example, treating rats with the organophosphate insecticide paraxoan increases the permeability of the BBB. The mechanism underlying the increase in permeability is under study. | 