Swallowing disorders are a common complaint among the elderly. Recently, surface electrical stimulation applied to the neck region has received increased attention as a new modality to treat pharyngeal dysphagia. Previous reports used pulsed current at a frequency range of 1-120 Hz. Kilohertz-frequency alternating currents (ACs) have not been tested for treating dysphagia. Therefore, we evaluated the effects of interferential currents (IFCs), the most popular modality of amplitude-modulated kilohertz-frequency ACs in clinical practice, on the swallowing reflex in healthy subjects. We found that IFC stimulation at the sensory threshold with 50-Hz modulation significantly increased the number of swallows without any discomfort, but pure AC stimulation at the carrier frequency did not have a significant effect. There was no statistically significant difference in the time course of the number of swallows among 1,000-, 2,000-, 4,000-, and 6,000-Hz carrier frequencies. The number of swallows remained increased during the 15-min IFC stimulation, suggesting that IFC stimulation facilitates the swallowing reflex without adaptation, at least during this stimulation period. We suggest that an IFC stimulation or a low-frequency, modulated kilohertz AC stimulation, which would be more comfortable than pulsed currents, is an alternative stimulation mode for treating pharyngeal dysphagia.

The aim of this study was to examine whether xanthine oxidase (XOD)-derived hepatic oxidative damage occurs in the main not during but following strenuous exercise. The degree of damage to hepatic tissue catalyzed by XOD was investigated immediately and 3 h after a single bout of exhausting exercise, in allopurinol and saline injected female Wistar rats. Allopurinol treatment resulted in increased hypoxanthine and decreased uric acid contents in the liver compared with the saline treated group, immediately and 3 h after the exercise. Analysis immediately after the exercise showed no changes in hepatic hypoxanthine, uric acid, and thiobarbituric acid-reactive substance (TBARS) contents in the saline treated group, when compared with the resting controls. However, significant increases in uric acid contents in the saline treated livers were observed 3 h after the exercise, relative to the controls. Hepatic TBARS content in the saline treated group were markedly greater than those in both the control and allopurinol treated groups after 3 h of recovery following the exercise. It was concluded that a single bout of exhausting exercise may impose XOD-derived hepatic oxidative damage, primarily during the recovery phase after acute severe exercise.

ObjectivesOur aim of this study was to quantify the physical demands of elite rugby union players by each position as a step towards designing position-specific training programme using a Global Positioning System/accelerometer system.MethodsThis study was performed as a retrospective observational study. Data were obtained from 45 official matches. The sample size used for the analysis was 298. The per-match total distances, accelerations and impacts were calculated and statistically compared for the forwards and backs and for individual positions.ResultsTotal distances for the forwards and backs were 5731.1±507.8 and 6392.1±646.8 m, respectively. The high-velocity running distances (>18.0 km/hour) covered by the forwards and backs were 317.4±136.9 and 715.0±242.9 m, respectively. The number of accelerations (>1.5 m/s2) for the forwards and backs were 76.3±18.9 and 100.8±19.6 times, respectively, and the number of high impacts (>10 g) were 48.0±46.9 and 35.6±28.3 times for the forwards and backs, respectively. All characteristics were significantly different between the forwards and backs (p<0.05). The per-position characteristics were also calculated. Within the backs, scrum half (SH) and wingers (WTBs) covered high-velocity running significantly higher distance than fly-half (SH d=2.571, WTBs d=1.556) and centres (SH d=1.299, WTBs d=0.685) (p<0.05).ConclusionBy clarifying the physical demands according to the positions, it will be possible to create optimised position-specific training programmes.

Sweat glands with a higher capacity for both sweat secretion and sodium reabsorption would contribute more effectively to thermoregulation, with less tendency to cause sodium depletion. The rate at which sweat glands reabsorb sodium and chloride does not increase proportionally as the rate of sweating increases, so that [Na + ] and [Cl -] in sweat sampled on the skin surface increase with sweating. It has been reported that there is a significant positive correlation between sweat secretory capacity and the capacity of sweat to reabsorb Na + (Sato and Dobson, 1970) and between sweat gland size and sweat secretory capacity (Sato and Sato, 1983). It has also been suggested that the sweat glands on the trunk may be larger than those on the limbs (Inoue and Shibasaki, 1996). Based on these findings, it is expected that the sweat glands on the trunk have a superior Na + reabsorptive capacity than those on the limbs. We know little about the slope of the relation of sweat [Na + ] to sweating rate at different body sites. Obtaining such information may be valuable to a better understanding of regional differences in sweat glands capacity for Na + reabsorption. Therefore, we compared the relationship between sweating rate and [Na + ] on the chest, back, forearm and thigh. MethodsThe subjects for this study were seven healthy male volunteers. The mean ± SD age, height, weight, . percentage body fat and maximal oxygen uptake (VO2max) of the subjects were 23.9 ± 4.7 years, 172 ± 3 cm, 69.35 ± 3.65 kg, 13.7 ± 1.7 % and 50.7 ± 4.2 mL · kg -1 · min -1 , respectively. Six of the men were college students who occasionally played various sports (rugby, soccer, golf and handball) and the remaining man was a laboratory researcher. All of the subjects were informed of the potential risks involved in participating in the study and gave their written consent.All of the experiments were conducted in August and September. The subjects refrained from food and water for at least two hours prior to each exercise session, to better control their state of hydration. There were no other dietary restrictions. The subjects, wearing only swimming trunks, pedaled a cycle ergometer for 60 min at different workloads (165-908 kpm · min -1 ) on separate days. Each subject carried out the 60-min exercise 4 to 7 times. Each 60-min exercise was performed in a climatic chamber, controlled at an air temperature of 30 ± 0.5°C and a relative humidity of 60 ± 5%. During the exercise, local sweat samples (12.6 cm 2 ) were collected successively on the chest (mid-pectoral), back (sub-scapular), forearm (mid-anterior), and thigh (mid-anterior) at 20 min intervals by the filter paper method (Inoue et al., 1991). . The local sweating rate (msw) on the chest, back, forearm, and thigh was then determined from the change in the weight of the filter paper, using an electronic balance accurate to ± 0.1 mg and expressed in mg · cm -2 · min -1 . The sodium concentration ([Na + ]) in the sweat was determined after eluting the Na + from the paper, and analyzing for Na + b...

The relationship between exercise-induced lowering of plasma glutamine concentrations and proliferation of peripheral lymphocytes was investigated in male Wistar rats. The T-lymphocyte proliferative responses to the mitogen, concanavalin A, were determined by incorporation of radiolabelled thymidine into the DNA in vitro. The rats ran 2 h x day(-1), 6 days x week(-1) for 4 weeks. Analysis immediately after the final period of exercise showed T-lymphocyte proliferation to be significantly depressed, together with a marked decrease in plasma glutamine concentrations. There were also significant increases in serum corticosterone concentrations immediately after exercise. However, following 24-h recovery, this exercise-induced immunosuppression was not statistically significant when compared with the age-matched control group. In the second experiment, in order to clarify the importance of glutamine for immunological function in vivo, methionine sulfoximine, an effective inhibitor of glutamine synthetase was injected intraperitoneally (12.5 mg x kg body mass[-1]). Plasma glutamine concentrations were decreased 4 h after the injection, compared with the placebo control group, and this resulted in a significant decrease in the rate of T-lymphocyte proliferation. This treatment had no effects on serum corticosterone concentrations. These results would suggest that the chronic exercise-induced reduction in proliferation of peripheral T-lymphocytes is a transient reversible phenomenon, which returns to normal levels within 24 h of the final training period. It is also conceivable that this exercise-induced immunosuppression is associated with a decrease in circulating glutamine concentrations.