Demography and epidemiology of aging in the United States / Dwight B. Brock, Jack M. Guralnik, and Jacob A. Brody -- Aging in protozoa / Joan Smith-Sonneborn -- Caenorhabditis elegans offers the potential for molecular dissection of the aging processes / Thomas E. Johnson -- Design, conduct, and analysis of human aging research / John W. Rowe, San Y. Wang, and Dariush Elahi -- Animal models in aging research / Edward J. Masoro -- Alterations in gene expression with aging / David B. Danner and Nikki J. Holbrook -- Modifications of proteins and nucleic acids by reducing sugars: possible role in aging / Annette T. Lee and Anthony Cerami -- Aging at the cellular level: the human fibroblastlike cell model / Thomas H. Norwood, James R. Smith, and Gretchen H. Stein -- Aging and the immune response / Richard A. Miller -- Heart and circulation / Edward G. Lakatta -- Age-related changes in synaptic neurochemistry / David G. Morgan and Patrick C. May -- Synaptic plasticity, neurotrophic factors, and transplantation in the aged brain / Carl W. Cotman -- Circadian rhythms and aging / Gary S. Richardson -- Central nervous system disorders in aging / Thomas B. Horvath and Kenneth L. Davis -- The adrenocortical axis / Robert M. Sapolsky -- Pharmacology and aging / Robert E. Vestal and Barry J. Cusack -- Nutrition and aging / Lynne M. Ausman and Robert M. Russell -- Physical exercise in the elderly / Andrew P. Goldberg and James M. Hagberg -- Chemical senses and aging / Linda M. Bartoshuk and James M. Weiffenbach.