Experimental gerontology
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Clinical experience gives rise to the impression that there are differences in fracture healing in different age groups. It is evident that fractures heal more efficiently in children than in adults. However, minimal objective knowledge exists to evaluate this assumption. ⋯ The biological basis of fracture healing will provide a context for revealing the pathophysiology of delayed or even impaired bone regeneration in the elderly. We will summarize experimental studies on age-related changes at the cellular and molecular level that will add to the pathophysiological understanding of the compromised bone regeneration capacity believed to exist in the elderly patient. We will suggest why this understanding would be useful for therapeutics focused on bone regeneration, in particular fracture healing at an advanced age.
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Experimental gerontology · Nov 2006
Molecular correlates of age-specific responses to traumatic brain injury in mice.
Aged traumatic brain injury (TBI) patients suffer higher rates of mortality and disability than younger patients. Cognitive problems common to TBI patients are associated with damage to the hippocampus, a central locus of learning and memory. To investigate the molecular mechanisms of age-related vulnerability to brain injury in a mouse model of TBI, we studied the effects of TBI on hippocampal gene expression in young and aged mice. ⋯ We compared injury-induced gene expression in hippocampal neurons of young and aged mice using quantitative ribonuclease protection assay analysis of linearly amplified mRNA from laser captured neurons. Both increased age and TBI were associated with increased expression of neuroprotective (brain-derived neurotrophic factor), pro-inflammatory (interleukin-1beta), and proapoptotic (caspase-3) genes in mouse hippocampal neurons. Our data support previous reports that suggested the CA3 subregion is highly susceptible to fluid percussion TBI and that age-related changes in gene expression are one potential mechanism of increased vulnerability of the aged brain to TBI.