1.INFLUENCE OF STRETCHING ON MUSCLE MASS DURING DETRAINING
MASASHI KASAHARA ; TOSHIHARU YAMAMOTO ; TAKASHI KAWAHARA
Japanese Journal of Physical Fitness and Sports Medicine 2010;59(5):541-548
The present study was conducted to examine whether stretching was effective to control muscular atrophy.Subjects were eight male undergraduate students (height 171.4 ± 5.8 cm, body weight 72.2 ± 7.8 kg, and age 20.6 ± 1.1 years) and the muscle analyzed was the vastus lateralis.Firstly, the subjects were instructed to perform strength training for a period of 16 weeks, which was followed by a 12-week detraining period. During the detraining period, either the right or the left leg was stretched daily for 10 minutes (2 sets). The mass of the vastus lateralis muscle was estimated based on its cross-sectional area (CSA), as assessed by magnetic resonance imaging (MRI). Relative decreases in muscle mass were compared between the stretched and the non-stretched control leg.Muscle mass in the non-stretched leg showed significant decreases during detraining, while no significant decreases in muscle mass were detected in the stretched leg. This outcome indicates that stretching can influence muscle plasticity and, therefore, is effective for preventing decreases in muscle mass.In conclusion, this study suggests that, added to its known ability to improve flexibility, accelerate recovery from fatigue, and prevent injuries, static stretching is effective for controlling muscle atrophy.
2.EFFECT OF ENDURANCE EXERCISE ON CARDIORESPIRATORY FUNCTIONS AND PERFORMANCE IN DEVELOPING AGE
KEIZO YAMAMOTO ; YORIKO ATOMI ; TAKASHI KAWAHARA ; TOSHIO ASAMI ; YOSHIO KURODA
Japanese Journal of Physical Fitness and Sports Medicine 1985;34(Supplement):165-170
In this study the effects of endurance exercise on cardiorespiratory functions and performance in developing age were exemined in 12 year old boys. Sujects were consisted of 11 boys who had been participating in training for soccer more than 2 hours a day for 6 days per week (S) and 10 non-participating boys for control (C) . Maximal oxygen uptake (Vo2max), maximal heart rate (HRmax) and maximal cardiac output (Qmax) by acetylnerebreathing method were measured on the exercise on a treadmill. Five minute run was also administered.
Significant differences were found in Vo2max (p<0.05), values of which were 2.13±0.07 1⋅min-1 for S. and 1.86±0.08 1⋅min-1 for C., respectively, and in Qmax (p<0.001), values of which were 17.9±1.41⋅min-1 for S. and 12.4+0.71⋅min-1 for C. G., respectively. There were no significant differences in HRmax and VE between both groups. Values of stroke volume and VE/Vo2max were significantly higher for S.. Performances on 5 minute-run were 1164 m for S. and 1083 m for C, which showed significant difference (p<0.01) . Significant correlationship (r=0.746, p<0.001) was obtained between Vo2max and Qmax. It was also found that the higher Vo2max was, the higher Qmax was attaind.
3.THE EFFECTS OF AEROBIC EXERCISE ON CARDIAC STRUCTURE IN 11-12 Y. O. BOYS
TAKASHI KAWAHARA ; KEIZO YAMAMOTO ; YORIKO ATOMI ; TOSHIO ASAMI ; YOSHIO KURODA
Japanese Journal of Physical Fitness and Sports Medicine 1985;34(Supplement):185-188
Little is known about the effects of aerobic exercise on cardiac structure in children. Echocardiographic study was performed at rest in 38 boys aged 11-12 (18 soccer players and 20 untrained) . Soccer players had significantly increased left ventricular end-diastolic dimension (43.6±2.8 vs 40.1±2.8 mm) and left atrial dimension (27.7±3.7 vs 23.0±2.8 mm) . There was no difference in interventricular septum and left ventricular posterior wall thickness between the two groups, these data show that intensive aerobic exercise may influence on cardiac structure in children.
4.PHYSIOLOGIC EFFECTS OF 1, 300 METERS ALTITUDE ON SWIMMING TRAINING
MITSUO NEYA ; MASAAKI SUGITA ; RYUJI KAWAMOTO ; KOJI WATARAI ; TAKASHI KAWAHARA
Japanese Journal of Physical Fitness and Sports Medicine 1999;48(3):393-402
To investigate effects of 1, 300 meters altitude on swimming training, several physiologic parameters were examined in eight female high school swimmers before, during and after living and training for six days at 1, 300 meters altitude.
Variables included peak heart rate (peakHR), rate of perceived exhaustion (RPE) and blood lactate concentration (BLa) associated with 200m swimming at submaximal and maximal speeds were measured 2-3 days before, during and 1-2 days after altitude exposure. Blood samples were collected before, during and after altitude exposure.
On day 1 of altitude exposure, peakHR and RPE at submaximal speeds increased from pre-altitude values while BLa didn't change. At maximal speed, swimming speed and BLa decreased, RPE increased, and peakHR didn't change from pre-altitude.
During altitude exposure, for the first three days of altiude exposure for peakHR and for all six days for RPE, the same submaximal speeds elicited greater values than pre-altitude.
Post-altitude BLa at submaximal speeds was reduced compared to pre-altitude. Maximal heart rate, RPE, and BLa at maximal speed didn't change pre- to post-altitude. However, mean values of them decreased from pre-altitude.
Erythropoietin was elevated above pre-altitude on day 2, and reticulocytes increased post-altitude significantly from pre-altitude.
These results indicate that the relative workload increased during the training at 1, 300 meters. There also appeared to be some stimulation for erythropoiesis.
In summary, this study found that 1, 300 meters altitude increased the difficulty of swimming training and six days at 1, 300 meters produced mild stimulation of erythropoiesis in these female swimmers
5.Physiologic effects of 1,300 meters altitude on swimming training.
MITSUO NEYA ; MASAAKI SUGITA ; RYUJI KAWAMOTO ; KOJI WATARAI ; TAKASHI KAWAHARA
Japanese Journal of Physical Fitness and Sports Medicine 1999;48(3):393-402
To investigate effects of 1, 300 meters altitude on swimming training, several physiologic parameters were examined in eight female high school swimmers before, during and after living and training for six days at 1, 300 meters altitude.
Variables included peak heart rate (peakHR), rate of perceived exhaustion (RPE) and blood lactate concentration (BLa) associated with 200m swimming at submaximal and maximal speeds were measured 2-3 days before, during and 1-2 days after altitude exposure. Blood samples were collected before, during and after altitude exposure.
On day 1 of altitude exposure, peakHR and RPE at submaximal speeds increased from pre-altitude values while BLa didn't change. At maximal speed, swimming speed and BLa decreased, RPE increased, and peakHR didn't change from pre-altitude.
During altitude exposure, for the first three days of altiude exposure for peakHR and for all six days for RPE, the same submaximal speeds elicited greater values than pre-altitude.
Post-altitude BLa at submaximal speeds was reduced compared to pre-altitude. Maximal heart rate, RPE, and BLa at maximal speed didn't change pre- to post-altitude. However, mean values of them decreased from pre-altitude.
Erythropoietin was elevated above pre-altitude on day 2, and reticulocytes increased post-altitude significantly from pre-altitude.
These results indicate that the relative workload increased during the training at 1, 300 meters. There also appeared to be some stimulation for erythropoiesis.
In summary, this study found that 1, 300 meters altitude increased the difficulty of swimming training and six days at 1, 300 meters produced mild stimulation of erythropoiesis in these female swimmers
6.CHARACTERISTICS OF BONE DENSITY IN ADOLESCENT SYNCHRONIZED SWIMMERS
CHIAKI TANAKA ; TADAYUKI IIDA ; YUKINORI TAWARA ; MITSUNORI MURATA ; JUNJI TAKAMATSU ; MIWAKO HOMMA ; TAKASHI KAWAHARA
Japanese Journal of Physical Fitness and Sports Medicine 2006;55(1):165-174
Forearm bone mineral content for adult white elite synchronized swimmers is lower than that of normative data (Roby et al. 1988). However, bone mineral density (BMD) in local body regions and the body as a whole are unclear in adolescent synchronized swimmers. The purpose of this study was to examine BMD of adolescent synchronized swimmers. This study also examined the relationship between BMD for young athletes and biological (e. g. morphological and functional aspects) and habitual (e. g. physical activity and nutritional state in daily living) variables. Subjects were nine females selected nationwide out of a large number of synchronized swimmers of fourth to sixth grade in elementary school, who participated in an audition with the committee of synchronized swimming in the Japan Swimming Federation. Chronological and bone age were 13.4±1.0 years and 12.7±0.9 years (n=8), respectively. BMD was evaluated in local regions and the body as a whole by dual X-ray absorbtiometry (DXA). Walking was measured by pedometer, and physical activity and nutritional status were analyzed by activity diary and food weighing method, respectively. As a result, mean BMD in athletes tended to be lower than in normal Japanese girls for lower limbs and lumbar vertebra (L2-L4), while it was almost the same between the two groups for whole body, upper limbs, thoracic vertebrae and pelvis. The correlations between BMD for whole body and bone age, the number of years since menarche, body mass, lean body mass and physical activity in leisure time of daily life were significant. An analysis using a general linear model indicated that bone age and active leisure activity together explained 94.6% of the variance of the BMD. These findings indicate that BMD of adolescent synchronized swimmers tended to be unique in local regions. Furthermore, BMD in athletes was affected by the biological maturation level and physical activity in leisure time of daily life.
7.THE ACTN3 R577X NONSENSE ALLELE IS UNDER-REPRESENTED IN ELITE-LEVEL JAPANESE ENDURANCE RUNNERS
DAICHI SAITO ; NORIYUKI FUKU ; ERI MIKAMI ; TAKASHI KAWAHARA ; HIROAKI TANAKA ; MITSURU HIGUCHI ; MASASHI TANAKA
Japanese Journal of Physical Fitness and Sports Medicine 2011;60(4):443-451
Background: Although previous reports have shown a lower proportion of the ACTN3 XX genotype (R577X nonsense polymorphism) in sprint/power athletes compared with controls, possibly attributed to the importance of skeletal muscle function associated with alpha-actinin-3 deficiency, the findings on association between endurance athlete status and R577X genotype are equivocal. Purpose: The present study was undertaken to examine association of ACTN3 R577X genotype with elite Japanese endurance athlete status. Subjects and Methods: Subjects comprised 79 elite Japanese endurance runners (E) who participated in competition at national level and 96 Japanese controls (C). We divided endurance runners into two groups, i.e., 42 national level runners (E-N) and 37 international level runners (E-I) who had represented Japan in international competition. R577X genotype (rs1815739) was analyzed by direct sequencing. Frequency differences of polymorphisms between athletes and controls were examined by Chi-square tests. Result: The R allele frequency tended to be higher in E group than in C group (P=0.066). When we divided E into two groups, the R allele frequency in E-I group was significantly higher than that in C group (P=0.046); whereas there were no significant differences between E-N and C groups (p=0.316). Then, the three genetic models were tested. In the additive genetic model (RR>RX>XX), there were significantly differences between E-I and C (P=0.038), but not the dominant (RR vs. RX+XX) and the recessive (RR+RX vs. XX) genetic models. Conclusion: R allele of the R577X genotype in the ACTN3 gene was associated with elite Japanese endurance athlete status.
8.High basal metabolic rate/fat-free mass ratio in Japanese elite male athletes can be attributed to body composition
Wakako Tatsuta ; Yukari Yokota ; Akiko Kamei ; Noriyuki Tawara ; Takashi Kawahara ; Motoko Taguchi ; Mitsuru Higuchi
Japanese Journal of Physical Fitness and Sports Medicine 2012;61(4):427-433
The aim of the present study was to evaluate the relation between basal metabolic rate (BMR) and body composition in 29 Japanese elite male athletes (age 25.6±3.7y, height 175.6±7.0cm, body weight 74.7±12.8kg, fat-free mass (FFM) 64.9±9.3kg). The subjects were classified into three groups according to their FFM. There was a significant difference in BMR/FFM between S-group (less than 0.5SD of average FFM) and L-group (more than 0.5SD). The parcentage of RM to body weight in S-group was significantly higher than in L-group. In conclusion, high basal metabolic rate/fat-free mass ratio in Japanese elite male athletes can be attributed to body composition.
9.Standards of Reporting Kampo Products (STORK) in research articles.
Yoshiharu MOTOO ; Takashi HAKAMATSUKA ; Nobuo KAWAHARA ; Ichiro ARAI ; Kiichiro TSUTANI
Journal of Integrative Medicine 2017;15(3):182-185
There had been no standardized rules for citing ethical Kampo products used in clinical trials in journal articles. Although the name of a Kampo manufacturer was described in 77.9% of research articles, the name and ratios of crude drug components of Kampo formulas were not described in 77.5% of these papers. Considering the importance of proper characterization of interventions in the Consolidated Standards of Reporting Trials (CONSORT) checklist, we hereby propose the use of the Standards of Reporting Kampo Products (STORK) website, http://mpdb.nibiohn.go.jp/stork, as a reference for Kampo products. This will provide an official source on the internet for verified information on individual Kampo formulations for citation purposes in clinical research articles.
10.An infertile patient with Y chromosome b1/b3 deletion presenting with congenital bilateral absence of the vas deferens with normal spermatogenesis.
Shinnosuke KURODA ; Kimitsugu USUI ; Kohei MORI ; Kengo YASUDA ; Takuo ASAI ; Hiroyuki SANJO ; Hiroyuki YAKANAKA ; Teppei TAKESHIMA ; Takashi KAWAHARA ; Haruka HAMANOUE ; Yoshitake KATO ; Yasuhide MIYOSHI ; Hiroji UEMURA ; Akira IWASAKI ; Yasushi YUMURA
Clinical and Experimental Reproductive Medicine 2018;45(1):48-51
We report the case of a 46-year-old Chinese male patient who visited our clinic complaining of infertility. Semen analysis revealed azoospermia, and azoospermia factor c region partial deletion (b1/b3) was detected using Y chromosome microdeletion analysis. Testicular sperm extraction was performed after genetic counseling. The bilateral ductus deferens and a portion of the epididymis were absent, whereas the remaining epididymis was expanded. Motile intratesticular spermatozoa were successfully extracted from the seminiferous tubule. On histopathology, nearly complete spermatogenesis was confirmed in almost every seminiferous tubule. To our knowledge, this is the first case report of b1/b3 deletion with a congenital bilateral absence of the vas deferens and almost normal spermatogenesis.
Asian Continental Ancestry Group
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Azoospermia
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Epididymis
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Genetic Counseling
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Humans
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Infertility
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Infertility, Male
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Male
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Middle Aged
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Semen Analysis
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Seminiferous Tubules
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Spermatogenesis*
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Spermatozoa
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Vas Deferens*
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Y Chromosome*