ABSTRACT
The present study aimed to examine the effects of Internet addiction on daily steps. A cross-sectional study was performed at the Osaka Institute of Technology. A total of 334 male college freshmen were analyzed. The participants were assigned to five groups according to Internet addiction levels. Internet addiction levels were assessed by Diagnostic Questionnaire, which has been reported by Young (1998), and we measured daily steps of the participants using a pedometer during usual 1 week. There were no significant trends or differences among five groups in physical characteristics of the participants, sleep duration, frequency of eating breakfast, and walking during commute time. However, with the level of Internet addiction increasing, daily steps showed a statistically significant decreasing trend. Therefore, Internet addiction levels might be related to reductions in steps in a dose-response manner. To clarify this point, further investigations will be required after considering confounding factors.
ABSTRACT
The present study aimed to investigate whether daily steps in male college students have actually decreased in the last decade. If the decline in steps is found, we additionally aimed to examine whether the decline in steps is attributed to a reduction of exercise or, rather, to a reduction of non-exercise activity. A serial cross-sectional study was performed from 2003 to 2012 at the Osaka Institute of Technology. A total of 1,215 male college freshmen were analyzed. Every year, scores of the physical activity levels were evaluated by a questionnaire, and we measured daily steps of participants using a pedometer during usual 1 week. Daily behavior record was also analyzed (n = 69). There were no significant trends or differences in characteristics of participants and the scores of physical activity levels throughout the 10 years. However, interestingly, significant decreasing trends were observed in the steps of average and weekend. In addition, daily behavior record analyses indicate that a cell-phone or a PC usage increased significantly in both weekday and weekend and that playing video games increased significantly in weekday. Therefore, these data support the view that daily steps have actually reduced in the last decade. Our findings also raise the possibility that the decline in steps may be related to the decline in non-exercise activity associated with the increase in a cell-phone or a PC usage and playing the video games.
ABSTRACT
Postoperative hypoxia in 53 consecutively treat patients who underwent coronary artery bypass grafting (CABG) and who were weaned from mechanical ventilation were studied. The 29 patients who required high concentration oxygen (more than 70% H-group) were compared with the 24 patients who required lower concentration oxygen (less than 70% L-group). The preoperative body mass index (BMI) was significantly higher in the H-group (25.6±3.5) than the L-group (23.3±2.8). (<i>p</i>=0.012). Respiratory index (RI) decreased after extracorporeal circulation in all patients. The RI of the H-group during a stay in intensive care unit was significantly lower than that in the L-group. The RI in obese patients (BMI≥26.5) showed a significant reduction. Late deaths were seen in 3 obese patients in the H-group. These data suggested that careful postoperative respiratory managements is necessary in obese patients.
ABSTRACT
To investigate whether muscle fiber conduction velocity reflects muscle fiber type, we studied the extensor digitorum longus (EDL) and soleus (SOL) muscle in 7 male rats aged 12 weeks. Muscle fiber conduction velocity was measured with a surface electrode array during stimulated contraction and calculated from the delay between two action potentials along muscle fibers for a given inter-electrode distance. Conduction velocity in the EDL (2.71±0.50 m/s) was significantly higher (p<0.05) than that in the SOL (2.14±0.34 m/s) . Fiber type, fiber area and fiber diameter were determinated by myosin ATPase staining and NADH-tetrazolium reductase staining. Muscle fiber composition of the EDL and SOL was 94.6±1.8 and 14.8±4.3% FT fibers, respectively, and mean muscle fiber diameter was 62.7±6.2 pm and 79.2±7.8pm, respectively, that of the EDL being significantly smaller (p<0.01) than that of the SOL. It was suggested that individual differences in conduction velocity were caused by differences in muscle fiber composition rather than differences in muscle diameter.