Effect of exercise on negative affect in residents in special care units with moderate to severe dementia.

Approximately 35% of individuals with dementia exhibit depression and/or anxiety symptoms, often manifested by symptoms of negative affect. Exercise has been associated with improved affect but has not been demonstrated to improve affect in residents of secured dementia units in long-term care facilities. This pilot study determined whether moderate-intensity, chair-based exercise was associated with changes in negative affect in residents in secured units. The sample included 36 patients from 2 nursing homes who participated in a 12-week, 30-minute moderate-intensity group exercise program thrice weekly. Affect, measured by the Philadelphia Geriatric Center Apparent Affect Rating Scale, was assessed at weeks 3 and 12, before and after each exercise session. Paired t tests assessed the immediate effect of exercise (before/after a session) and the long-term effect of exercise (study initiation/12 wk) on patients' affect ratings. The mean age was 85 years (SD=5.5), with 86% female, and 97% white. At week 3, anxiety was significantly lower immediately after the exercise session when adjusted for level of participation (P=0.02) compared with immediately before the exercise session, indicating immediate changes in affect. Anxiety and depression were significantly reduced at week 12, when compared with week 3, after adjusting for level of participation (P=0.01; P=0.03), indicating long-term effects of the exercise intervention. The study revealed the feasibility of conducting a moderate-intensity exercise program and the potential for exercise as a nonpharmacologic intervention for reducing symptoms of negative affect and depression in this vulnerable population.

Effects of distraction on muscle length: mechanisms involved in sarcomerogenesis.

Although a great deal of interest has been given to understanding the mechanisms involved in regulating the radial growth that occurs because of resistance training, much less has been given to studying the longitudinal growth of skeletal muscle that occurs because of passive stretch. The current authors provide a brief overview of key issues relevant to the longitudinal growth of skeletal muscle that occurs during distraction osteogenesis. Specifically, five key issues are addressed: (1) the pattern of sarcomerogenesis during distraction; (2) sarcomerogenesis and altered expression of sarcomeric and nonsarcomeric genes; (3) the satellite cell hypothesis; (4) mitogenic factors; and (5) new approaches for studying the longitudinal growth of skeletal muscle. A discussion is provided that revolves around the concept of a negative feedback loop. One of the most interesting issues to be resolved in muscle biology is the role of satellite cells in regulating the growth of skeletal muscle. Currently, it is not known whether satellite cell activation is a prerequisite for the longitudinal growth of skeletal muscle. Gene chip analyses provide a paradoxical view, showing that distraction osteogenesis results in the upregulation of a gene, GADD45, involved with growth arrest and deoxyribonucleic acid destruction.