MUSCLE BIOPSY FRAIL VS NON-FRAIL

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This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. Although frailty has been difficult to define, Fried and her colleagues have established criteria for frailty based on physical ad psychological characteristics. These characteristics include unintentional weight loss (10 or more pounds per year), self-reported exhaustion, weakness as measured by grip strength, slow walking speed, and low physical activity (Fried et al., 2001). With a framework to examine frailty, we propose to explore more fully the pathophysiology of sarcopenia in frail and non-frail older individuals. In Frontera et al. 2000 and Balagopal et al. 1997, the authors hypothesized that sarcopenia largely results from the decreased ability for the replacement of dysfunctional contractile proteins within the myofilament lattice. Exploiting the signal in Second Harmonic Imagine Microscopy (SHIM), which is derived from and sensitive to the local density and alignment of contractile proteins within muscle sarcomeres, this new mode of non-linear laser-scanning microscopy will allow quantitative analysis of both the histology and molecular structure of completely native, intact muscle tissue. Thus far, few studies to date have provided extensive and quantitative ultrastructural examination of muscle from very old individuals (Frontera et al. 2000). Fiatarone Singh and colleagues, reported data outlining aspects of muscle damage in frail elders using electron microscopy, which has limitations in comparison to SHIM.