A small amount of the myotube-like structures (chained nuclei) are present in skeletal muscle independently of disease. These experiments show that the incidence of the myotube-like structure increases with the advance of age in mice. Moreover, it is shown that the DNA in the myotube-like structure is not fragmented. That is, the myotube-like structures were TUNEL (Terminal deoxynuc-leotidyl transferase (TdT) -mediated dUTP-biotin Nick-End labeling) negative. Moreover, we detected the polyadenylated mRNA around the myotube-like structure by using an in situ hybridization technique. This suggests that the myotube-like structure has transcription activity. This report indicates that the myotube-like structure is a useful indicator of aging in skeletal muscle.
The purpose of this study was to implement a community-based exercise program for postdischarge stroke survivors in the public health center. The subjects were fourteen male stroke survivors with chronic upper and lower limb paresis (63.0±5.9 years) . The study design was quasiexperimental, with each subject serving as his own control. All subjects have to meet following inclusion criteria: (1) first stroke resulting in hemiplegia, (2) at least 6 months post-stroke, (3) able to walk independently, and (4) free from grave aphasia, apraxia, agnosia, or disequilibrium. A 25-week (2 deek) training program consisted of a warm-up, lower and upper extremity muscle strengthening, recreational activities, walking training, and a cool down. The duration of this program is approximately 70 minutes a day. The outcome measure was the 12 functional fitness test items and questionnaire in activities parallel to daily living. Significant improvements (P<0.05) were found for handgrip strength, knee extension strength, tandem balance, standing and sitting, and timed up and go in the treatment period. However, the scores in activities parallel to daily living were not significant. These results suggest that they may attain significant functional improvements in response to implementation of a community-based exercise program. In conclusion, post-discharge stroke survivors can improve their functional fitness status by participating in a community-based exercise program.
This study examined the effects of physical training on exercise hyperpnea (EH) in patients on hemodialysis (HD) . In baseline, 17 (trained group) and 12 (control group) patients on HD performed symptom limited exercise test using a treadmill. Trained group, but not control group, exercised 2 to 3 times weekly on non-dialysis days under medical supervision. Exercise testing was repeated 20 weeks after the baseline. Ventilatory response to exercise was evaluated using the regression slope relating minute ventilation (VE) to carbon dioxide output (VCO2 ) during incremental exercise (VE/VCO2 slope) below the point of respiratory compensation. In trained group, VE, oxygen uptake ( VO2) and VCO2 at peak exercise increased and VE/VO2 and VE/VCO2 decreased after physical training, respectively. No change was observed in control group. VO2 at the anaerobic threshold increased in trained group, but not in control group. The post training VE/VCO2 slope (33.9±5.0) was significantly (p<0.05) lower than the pre-training slope (38.0± 4.8) and remained constant in control group. In trained group, changes in the VE/VCO2 slope correlated with those in peak VO2 (p<0.05) . These results suggest that physical training decreases EH in patients on HD and that it correlates with changes in exercise tolerance.
This study evaluated the relationship between walking speed and energy metabolism. The speed at which energy consumption per km of walking was lowest was defined as“economical speed”; the speed at which each subject felt most natural was defined as“comfortable speed”; and the fastest speed at which each subject was able to walk was defined as“fast speed”. Energy consumption during 60-minutes of walking was 342±11 kcal at fast speed, 248±13 kcal at comfortable speed, and 201± 17 kcal at economical speed. The value at fast speed was significantly higher than at other speeds (P<0.001) . As for source of energy consumption, energy derived from carbohydrates was 233±16 kcal at fast speed, accounting for 68% of total energy consumption, 149±19 kcal at comfortable speed, and 109±13 kcal at economical speed. Energy derived from fat was 109±10 kcal at fast speed, 99±14 kcal at comfortable speed, and 92±12 kcal at economical speed, with no significant difference among the 3 speeds. No difference was observed among the 3 speeds in change in plasma lipid levels after walking compared with before walking.