1. Department of Pathology (R.A.M., Y.C.), Ann Arbor, Michigan 48109
2. Geriatrics Center (R.A.M., A.T.G.), Ann Arbor, Michigan 48109
3. Institute of Gerontology (R.A.M., A.T.G.), University of Michigan, Ann Arbor, Michigan 48109
4. Department of Physiology (K.A.-R., A.B.), Southern Illinois University, Carbondale, Illinois 62901-6512
5. Department of Biomedical Sciences (J.J.K.), College of Osteopathic Medicine and Edison Biotechnology Institute, Ohio University, Athens, Ohio 45701