Relationship between breath isoprene excretion and oxidative stress responses to submaximal exercise / 体力科学

The physiological functions of expiratory isoprene, which is abundantly contained in human breath, are not well known. Recently, breath isoprene has been proposed to be related to oxidative stress, although no direct evidence has been reported. Therefore, the purpose of this study was to investigate the relationship between breath isoprene and oxidative stress status. Ten healthy male subjects performed a 20-min submaximal step-load cycling exercise, the intensity of which corresponded to a 60% peak oxygen uptake after a 10-min rest. Breath isoprene excretion during the exercise was calculated from the product of minute ventilation and isoprene expiratory concentration. To evaluate the oxidative stress, we collected blood samples from the subject’s fingertips before and immediately after the end of the exercise, and then diacron reactive oxygen metabolites (d-ROMs), which is an index of oxidative stress level, and biological antioxidant potential (BAP), which is an index of antioxidant potential, were measured. The breath isoprene concentration at the rest was significantly positively correlated with the ratio from BAP to d-ROMs (BAP/d-ROMs), which is an index of latent antioxidant potential (r = 0.63, P < 0.05). Furthermore, the change in breath isoprene excretion from before to after the exercise was significantly negatively correlated with the change in d-ROMs (r = -0.73, P < 0.05) and positively correlated with the change in BAP/d-ROMs (r = 0.88, P < 0.01). These results suggest that isoprene might play a role in the control of oxidative stress.

Validation of the Japanese Version of the Balance Evaluation Systems Test (BESTest) / The Japanese Journal of Rehabilitation Medicine

Objective : The Balance Evaluation Systems Test (BESTest) is a new balance assessment set based on systems theory. The purpose was to examine the validity of the Japanese version of the BESTest (J-BESTest) that we translated. Methods : The J-BESTest was produced using a translation and back translation method referenced from a guideline proposed by Guillemin et al. We tested 20 patients with balance dysfunction due to various diseases and 5 healthy persons with the J-BESTest, the Berg Balance Scale (BBS), the Falls Efficacy Scale-International (FES-I) and the Activities-specific Balance Confidence Scale (ABC Scale). We assessed the concurrent validity of the J-BESTest by comparing it with the other measures using Spearman's correlation method. Furthermore, we compared the ability of the J-BESTest to discriminate balance dysfunction with that of the BBS using receiver operating characteristic (ROC) analyses. Results : The J-BESTest was highly correlated with BBS (<i>r</i>=0.84, <i>p</i><0.01), FES-I (<i>r</i>=-0.61, <i>p</i><0.01) and ABC Scale (<i>r</i>=0.63, <i>p</i><0.01). The distribution of the BBS score was more skewed compared with the J-BESTest and had a ceiling effect (6 participants had perfect scores with BBS versus none with the J-BESTest). The area under the ROC curve (AUC) of the J-BESTest was significantly larger than that of BBS (BBS 0.75, 95% confidence interval 0.56-0.94 versus J-BESTest 0.94, 95% confidence interval 0.84.1.0, <i>p</i><0.05). Conclusion : The J-BESTest was suggested as a clinically useful tool, with good concurrent validity and better sensitivity and specificity than BBS, to identify people with mild balance dysfunction.

Validation of the Japanese Version of the Mini-Balance Evaluation Systems Test (Mini-BESTest) / The Japanese Journal of Rehabilitation Medicine

Objective : The Mini-Balance Evaluation Systems Test (Mini-BESTest) is an assessment tool for dynamic balance dysfunction developed by simplifying the Balance Evaluation Systems Test (BESTest). The purpose of our study was to examine the validity of the Japanese version of the Mini-BESTest (J-Mini-BESTest) we translated. Methods : The J-Mini-BESTest was produced using a translation and back translation method referring to a guideline proposed by Guillemin et al. We tested 20 patients with balance dysfunction due to various diseases and 7 healthy persons with the J-Mini-BESTest, the Berg Balance Scale (BBS), the Falls Efficacy Scale-International (FES-I) and the Activities-specific Balance Confidence Scale (ABC Scale). We assessed the concurrent validity of the J-Mini-BESTest by comparing it with the other measures using the Spearman's correlation method. Results : The average assessment time when using the J-Mini-BESTest was 20.0 minutes. The J-Mini-BESTest was correlated with the BBS (<i>r</i>=0.82, <i>p</i><0.01), FES-I (<i>r</i>=-0.72, <i>p</i><0.01) and ABC Scale (<i>r</i>=0.80, <i>p</i><0.01). The distribution of the BBS scores was more skewed compared to the J-Mini-BESTest (BBS skewness=-1.30 vs. J-Mini-BESTest skewness=-0.47) and the BBS also had a ceiling effect (9 participants had a perfect score in the BBS versus none in the J-Mini-BESTest). Conclusion : The J-Mini-BESTest was suggested as a clinically useful tool for detecting subtle dynamic balance deficits with good concurrent validity.

EFFECT OF ENDURANCE TRAINING ON PANCREATIC EXOCRINE RESPONSE TO CHOLECYSTOKININ (CCK) IN RATS / 体力科学

In the previous studies, we found that endurance training increased pancreatic weight, protein content, and enzyme activity with hypertrophied acinar cells in rats. The purpose of the present study was to investigate the effect of endurance training on pancreatic exocrine response to CCK in rats. Female F344 rats were divided into control (C, n=6) and endurance training (T, n=6) groups. The trained rats were exercised for 60 min on a treadmill (final speed, 35 m/min), 5 days a week, for 8 weeks. Food intake in both groups was matched. On the final day of the experiment, the rats were anesthetized after an overnight fast and prepared with cannulae into the pancreatic duct. After 1-h basal collection with 0.9% NaCl (7.5 ml/kg body weight/h) injected intravenously, CCK-8 (0.06μg/kg body weight/h) was injected intravenously and pancreatic secretions were collected for the additional three 1-h periods. Final body weight in the T group was slightly, but not significantly, lower than in the C group (C : 145±6, T : 137±8 g). Pancreatic wet weight in the T group was significantly higher than in the C group (C : 4.14±0.16, T : 4.71±0.18 mg/g BW). CCK-stimulated pancreatic juice secretion was not significantly changed. There were significant increases in pancreatic protein and amylase secretions with CCK administration. CCK-stimulated pancreatic protein and amylase secretions were significant higher in the T group than in the C group. Total pancreatic protein secretion with CCK administration during 3 hours were significant higher in the T group than in the C group (C : 2.52±1.92, T : 5.11±1.50 mg/3 h). Total amylase secretion with CCK administration during 3 hours were also significant higher in the T group than in the C group (C : 0.69±0.43, T : 1.12±0.37 U/3 h). These results suggest that the endurance training increased pancreatic exocrine secretion response to CCK. CCK may play an important role in exercise-induced enhancement of the exocrine pancreas.

Effects of voluntary training on pancreatic enzyme activity and acinar cells in rats / 体力科学

The authors have found that compulsory training using treadmill running increases pancreatic weight, protein content, and enzyme activity in hypertrophied acinar cells in rats. The purpose of the present study was to investigate the effect of voluntary running exerise on the exocrine pancreas in rats. Female F344 rats were divided into control, compulsory training, and voluntary training groups. The compulsory trained rats were exercised for 60 min on a treadmill (final speed, 35 m/min), 5 days a week, for 8 weeks. The voluntary trained rats were exercised on a voluntary basis on a wheel ergometer with a load of 30% of their body weight every day. Mean running distance for the voluntary training group was 5.2±1.0 km/day. Final body weight for the compulsory and voluntary training groups was significantly lower than for the control group. Soleus muscle weight and citrate synthase activity of the plantaris muscle for the compulsory and voluntary training groups were significantly higher than for the control group. Pancreatic wet weight, protein content, and amylase and lipase activities for the compulsory and voluntary training groups were significantly higher than for the control group. Pancreatic wet weight, protein content, and amylase and lipase activities for the compulsory and voluntary training groups were significantly higher than for the control group. Total DNA content of whole pancreas in the voluntary training group was significantly higher than for the control and compulsory training groups. Electron micrographs revealed that acinar cells obviously hypertrophied and zymogen granules increased in the compulsory and voluntary training groups rats compared with the compulsory group. These results suggest that voluntary training increases pancreatic weight and protein content in hypertrophied and/or hyperplasic acinar cells, which in turn increases synthesis and the storage of exocrine pancreatic enzymes.