ABSTRACT
To investigate the factors affecting the rate of improvement in endurance exercise performance following pre-cooling with ice slurry, we focused on individual physical characteristics and thermoregulatory capacity. Twenty-four healthy adults (12 males and 12 females) ingested 7.5g kg-1 of either ice slurry at -1°C (ICE) or control water at 20°C (CON) before cycling at 55% VO2max and continued cycling until the rectal temperature reached 38.5°C or untill exhaustion in a hot environment (controlled at 38°C, 40% relative humidity). The relationship between the rate of improvement in exercise performance and physical characteristics and thermoregulatory factors (changes in rectal temperature, the rate of rectal temperature increase, whole body sweat loss, mean metabolic heat production, and heat storage) was investigated. No correlation was noted between the rate of improvement in exercise performance and physical characteristics and heat storage. On the other hand, the rate of improvement in exercise performance showed significant correlations with changes in rectal temperature (r = -0.497), the rate of rectal temperature increases during exercise (r = -0.784), whole body sweat loss (r = 0.407), and mean metabolic heat production (r = -0.436). The rate of inhibition of sweating and the rate of increase in metabolic heat production by ice slurry ingestion during exercise have been suggested to be related to the rate of improvement in exercise performance. On the other hand, there was no relationship between body composition or VO2max and the rate of improvement in exercise performance.
ABSTRACT
Several studies have reported that molecular hydrogen (H<sub>2</sub>) acts as a therapeutic medical gas owing to scavenging reactive oxygen species (ROS). However, little is known about effects of H<sub>2</sub> on exercise-induced oxidative stress. The purpose of this study was to investigate the effects of weekly hydrogen bathing on exercise-induced oxidative stress and delayed-onset muscle soreness (DOMS). Nine healthy and active young men participated in this study, and each subject performed hydrogen bathing trial and placebo bathing trial in a crossover design. The subjects performed downhill running (8 % decline) at 75 % peak oxygen uptake (VO<sub>2</sub>peak) for 30 min, and each subjects conducted hydrogen or placebo bathing for 20 min, respectively, 1-6 days after downhill running. Before and after exercise, we measured visual analogue scale (VAS) and collected blood samples (Pre- and 5 min, 60 min after the end of bathing, 1day, 2days, 3days, 7days after downhill running). Blood sample analyses include creatine kinase (CK), myoglobin (Mb), malondialdehyde (MDA), reactive oxygen metabolites (d-ROMs), biological antioxidant potential (BAP), myeloperoxidase (MPO), interleukin-6 (IL-6), interleukin-17a (IL-17a) and lactate concentrations. Weekly hydrogen bathing had no effects of exercise-induced oxidative stress and muscle damage. On the other hand, hydrogen bathing significantly reduced DOMS (VAS) 1 and 2days after downhill running (p=0.033). These findings suggest that hydrogen bath after downhill exercise can be effective for reduction of DOMS.
ABSTRACT
A 61-year-old woman underwent a regular echocardiography in October 2008 in which a mass of 1 cm in diameter was pointed out in the left ventricle apex. It did not dcrease, in spite of anticoagulation therapy, and therefore we performed surgery. The tumor was confirmed on the septal side of the cardiac apex by intraoperative cholangioscopy, and it was excised through the mitral valve. It was diagnosed as myxoma on immediate intraoperative pathological examination, and we confirmed that there was no tumor remnants on the resected stump histologically. The patient was discharged on the 13th day after the operation and 2 years later she was alive without recurrence of the tumor. This is the 25th case of left ventricular myxoma in Japan. In these reports, an initial resection of the tumor in the left ventricle was performed in 23 cases and the approach methods were described in 20 cases. The evaluation of the resected stump, regardless of remaining tumor, was described in only 3 cases. There were no reports of relapse after the operation. There are many reports which emphasize the usefulness of echocardiography, which is very helpful not only in the diagnosis, but also in periodic evaluations after the operation.
ABSTRACT
A 76-year-old-woman, who had undergone endoscopic resection of a gastric polyp 2 years previously, had a cardiac tumor incidentaly pointed out on an abdominal ultrasonographic image. Echocardiography showed a solid round mass (34×25 mm in diameter), attached by a short stalk and which was floating on the right ventricular outflow tract and prolapsing over the pulmonary valve during systole. We suspected right ventricular myxoma. Urgent surgery was performed under cardiopulmonary bypass. After aortic clamping, the trunk of the pulmonary artery was opened near the right ventricule. The tumor was found under the pulmonary valve, attached to the anterior papillary muscle and chordae of the tricuspid valve. The tumor was completely excised with a piece of the papillary muscle and chordae. After right atriotomy, mild tricuspid regurgitation was seen on a water test. After we performed tricuspid annuloplasty and chordplasty with artificial chordae, a second water test did not show any tricuspid regurgitation. The postoperative course was uneventful, and she was discharged on the 13th postoperative day.