Repeated contractions of skeletal muscle cause fatigue, as manifested by a reduced ability to produce force and slowed contraction. During studies of muscle fatigue, a phenomenon known as low-frequency fatigue (LFF) was observed in human skeletal muscles. It is characterized by a greater loss of force in response to low- versus high-frequency muscle stimulation and a long period of time for full recovery. This force deficit is most likely to be owing to disturbances in sarcoplasmic reticulum (SR) Ca²⁺ release and/or reductions in myofibrillar Ca²⁺ sensitivity. Studies on metabolites have implied that inorganic phosphate and Mg²⁺ might have some role in reduced SR Ca²⁺ release that occurs immediately after fatiguing contraction. In addition, recent experiments have shown that impaired myofibril function may relate to increased nitric oxide and hydroxyl radical production, whereas deterioration of SR function may be attributable to increased superoxide production, elevation of cytoplasmic Ca²⁺ concentration and/or decreased muscle glycogen. Finally, we will discuss possible proteins which are affected and contribute to the development of LFF.

We report two cases of myoclonus following the administration of gabapentin for neuropathic pain in the end stage of malignancy. Patient 1: A septuagenarian woman with sarcoma of the uterus was admitted to our hospice. She complained of severe neuropathic pain in her left leg caused by an invasive lumbar tumor. To reduce the neuropathic pain, she was administered 200mg of gabapentin daily. Four months later, the gabapentin was increased to 400mg daily due to worsening pain in her left leg. Three days later, she felt muscle weakness in her left arm and frequent muscle twitches were observed even during sleeping. Myoclonus associated with gabapentin administration was suspected. The myoclonus disappeared after cessation of gabapentin for 2 days. Patient 2: An octogenarian man with renal cell carcinoma was admitted to our hospice. He was administered 200mg of gabapentin daily to reduce the neuropathic pain felt in his back and bilateral leg due to a metastatic tumor of a para-aortic lesion. On the next day, frequent muscle twitches were observed in his extremities and upper trunk while he was sleeping. Myoclonus associated with gabapentin administration was suspected, which disappeared within one day following cessation of the drug. Myoclonus is a rare side effect of gabapentin, but it may occur even with the low-doses given to patients with end-stage malignancy. Although the pathogenic mechanism of induction of myoclonus by gabapentin was suspected to be heterogeneous, discontinuation of gabapentin should lead to rapid resolution of symptoms. Palliat Care Res 2010; 5(1): 308-313

To investigate the influences of high-intensity training and/or a single bout of exercise on in vitro Ca²⁺-sequestering function of the sarcoplasmic reticulum (SR), the rats were subjected to 8 weeks of an interval running program (final training : 2.5-min running×4 sets per day, 50 m/min at 10% incline). Following training, both trained and untrained rats were run at a 10% incline, 50 m/min for 2.5 min or to exhaustion. SR Ca²⁺-ATPase activity, SR Ca²⁺-uptake rate and carbonyl group contents comprised in SR Ca²⁺-ATPase activity were examined in the superficial portions of the gastrocnemius and vastus lateralis muscles. For rested muscles, a 12.7% elevation in the SR Ca²⁺-uptake rate was induced by training. Training led to improved running performance (avg time to exhaustion : untrained-191.1 vs trained-270.9 sec ; P<0.01). Regardless of training status, a single bout of exercise caused progressive reductions in SR Ca²⁺-ATPase activity and SR Ca²⁺-uptake rate. Increases in carbonyl content only occurred after exhaustive exercise (P<0.05). At both point of 2.5-min and exhaustion, no differences existed in SR Ca²⁺-sequestering capacity and carbonyl content between untrained and trained muscles. These findings confirm the previous findings that oxidative modifications may account, at least partly, for exercise-induced deterioration in SR Ca²⁺-sequestering function ; and raise the possibility that in the final phase of acute exercise, high-intensity training could delay the progression of protein oxidation of SR Ca²⁺-ATPase.

Boi-ogi-to is frequently prescribed to relieve pain for osteoarthritis in the therapy of Kampo formulation. However, it has been pointed out that the evaluation of this formulation differs among the patients. It is often showed lower effectiveness and/or non-effectiveness in the patients with advanced roentgenographic deformity, obesity, and suffering from more severe pain.
We thought that it was resulted from ingoring the abdominal-sho (symptom). Therefore, in this study, we defined the abdominal-sho of Boi-ogi-to as “frog abdominal-sho”, and administered Boi-ogi-to to 17 patients with osteoarthritis of the knee who had frog abdominal sho. As a result, in the patients with frog abdominal-sho, the formulation was moderately or even better effective in relieving pain in 77% of these patients. It was acknowledged that the effect was independent of the severity of pain, the degree of obesity, and whether the roentgenographic deformity was slight or moderate.

The relationships between physical activity and childhood body size, low physical fitness epidemic are still unclear. The purpose of this study was to examine the relationship between energy expenditure estimated by doubly labeled water (DLW) method and body fatness, physical fitness in children, and the relationship between physical activity levels and percent time spent in activities. 30 healthy Japanese children (20 boys and 10 girls) participated in this study. The total energy expenditure (TEE) and % body fat were measured by the DLW method over a 6-day period. The physical activity-related energy expenditure (PAEE) was calculated as (TEE × 0.90) – basal metabolic rate (BMR). The physical activity level (PAL) was also calculated as TEE/BMR. The physical fitness tests (8 items) were applied to evaluate fitness, and scores of each test were calculated as overall physical fitness score. The TEE was 2009.8 ± 272.6 kcal/day, the PAEE was 558.4 ± 206.1 kcal/day and the PAL was 1.61 ± 0.18. TEE per weight and PAEE per weight (PAEE/wt) was significantly negatively correlated with % body fat (r = - 0.626; r = - 0.400, respectively). These results suggest that increasing energy expenditure is important for achieving adequate body size. The PAEE/wt was most strongly correlated with physical fitness score (r = 0.680). The PAL was associated with percent time spent of inactivity ( r = -0.506), light-moderate activity ( r = 0.450) and vigorous activity ( r = 0.545). It was suggested that physically active lifestyle would be necessary for childhood health.

The purpose of this study was to examine the relationships between patterns of daily physical activities measured by accelerometer and physical activity level (PAL) in children. Firstly, activity intensities during incremental exercise were measured using a tri-axial accelerometer (HJA-350IT) in twenty one children aged 10.6 ± 0.9 years. As a result of receiver-operating characteristic curve analysis, the cut-off value for discrimination between walking and running activity was set at 7.2 METs of HJA-350IT. Secondly, total energy expenditure (TEE) in daily life was measured by doubly labeled water method, and durations of lifestyle, walking, and running activities were measured by the accelerometer in 6^th grade elementary school children (11 boys and 10 girls). TEE and physical activity level (PAL) were 2,021 ± 343 kcal/day and 1.56 ± 0.17, respectively. The average durations of lifestyle, walking and running activities were 188 ± 30 min/day (50.6 ± 6.0 %), 171±28 min/day (45.9 ± 5.0 %) and 13.3 ± 7.6 min/day (3.5 ± 1.8 %), respectively. The proportion of the duration of running activity was positively correlated with PAL (r = 0.615, p < 0.01), and the proportion of the duration of lifestyle activity was negatively correlated with PAL (r = -0.439, p < 0.05). There was no relationship between the proportion of the duration of walking activity and PAL (r = 0.300, n.s.). These results suggest that running activity is important to increase PAL more than ever in primary school children.

We conducted an anonymous questionnaire survey to examine the results of regularly drinking FFC beverage. Over 70% of participants reported a positive reaction through consumption. By contrast, few negative reactions were recorded (0.7%). These would suggest its effectiveness as a health drink. Positive reactions were significantly related to the amount of FFC beverage consumed each day, the reason for starting to drink FFC beverage, participant’s age, the amount of FFC beverage consumed each time, and the no use of the other functional foods.