Edward L. Schneider

Lower Organisms: Identification of Longevity. Assurance Genes in Yeast. Molecular Genetic Approaches to Identifying Gerontogenes in Caenorhabditis Elegans. Genetic Approaches to Life Prolongation in Drosophila Melonogaster. Mutants Affecting Senescence Processes in Plants. Changes in Gene Expression with Aging. Molecular and Cellular Biology: Mechanisms Controlling in Vitro Cellular Senescene. Mechanisms of Altered Gene Expression with Aging. Protein Modifications. Genomic and Mitochondrial DNA Alterations and Aging. Neurobiology: Neurobiological Correlates of Age-Related Cognitive Decline: Animal Models. Neuropyschological Assessment of Age-Related Cognitive Decline in Humans. Neuroendocrine Changes in Aging. Nerve Growth Factors, Neural Plasticity, And Aging. Human Biology: Aging Renal Function and Regulation of the Volume and Composition of the Extra Cellular Fluid. Depression in Old Age. Menopause and Its Consequences. Skeletal Integrity and Osteoporosis in Old Age. Overarching Areas: Excercisephysiology and Aging. Nutrition and Aging. Epidemiology of Aging.

Differences between early and late passage cell cultures on the organelle and macromolecular levels have been attributed to cellular "aging". However, concern has been expressed over whether changes in diploid cell populations after serial passage in vitro accurately reflect human cellular aging in vivo. Studies were therefore undertaken to determine if significant differences would be observed in the in vitro lifespans of skin fibroblast cultures from old and young normal, non-hospitalized volunteers and to examine if parameters that change with in vitro "aging" are altered as a function of age in vivo. Statistically signigificant (P less than 0.05) decreases were found in the rate of fibroblast migration, onset of cell culture senescence, in vitro lifespan, cell population replication rate, and cell number at confluency of fibroblast cultures derived from the old donor group when compared to parallel cultures from young donors. No significant differences were observed in modal cell volumes and cellular macromolecular contents. The differences observed in cell cultures from old and young donors were quantitatively and qualitatively distinct from those cellular alterations observed in early and late passage WI-38 cells (in vitro "aging"). Therefore, although early and late passage cultures of human diploid cells may provide an important cell system for examining loss of replicative potential, fibroblast cultures derived from old and young human donors may be a more appropriate model system for studying human cellular aging.