1. Department of Physiology (V.C., C.R.D., E.R.M., A.B.), Southern Illinois University School of Medicine, Carbondale, Illinois 62901;
2. Internal Medicine (J.S.R., A.B.), Southern Illinois University School of Medicine, Springfield, Illinois 62794;
3. Biomedical Sciences Department and Edison Biotechnology Institute (J.J.K.), College of Osteopathic Medicine, Ohio University, Athens, Ohio 45701