Comparison of V̇O2 for buoyancy and propulsion during swimming between male and female

体脂肪は人体の水中体重を小さくするから, 水泳には体脂肪の多いことが有利な条件となる可能性がある。本研究は水泳の際に浮くために使われるV̇O2と推進のために使われるV̇O2を測定し, 水中体重の大小が実際の水泳にどれほどの影響を与えているかという点について検討したものである。 男女各3名, 計6名の泳者に, 泳速が0.6, 0.8及び1.0m/secのクロール泳を行わせ, V̇O2を測定した。その際腰に錘をつけて水中体重を増加させ, あるいは滑車を介した錘で腰を引き上げるようにして水中体重を減少させ, 各水中体重において上記の測定を行った。V̇O2値を水中体重に対してプロットすることによって得られる回帰直線の勾配から浮くためのV̇O2を, またY切片から安静時V̇O2を差し引くことによって推進のためのV̇O2を求めた。 1 浮くために必要なV̇O2は泳速とは無関係であり, その平均値は男子の方(352±140ml/min)が女子のそれ(186±83ml/min)より有意に大であった。この差は水中体重に大きく依存していて, 単位水中体重当りに換算すると男女の値は接近した(男子: 117±46ml/min, 女子: 91±36ml/min)。 2 推進のために用いられるV̇O2は, 泳速の増加に伴って指数関数的に増大した。その増加率は男子よりも女子の方が大であったが, それは女子の水泳能力が男子のそれより劣ることに関連していると考えられる。 3 総V̇O2に対する推進のためのV̇O2の割合は, 男子よりも女子において大きく, この点女子の水中体重の小さいことは水泳において有利な条件になっている。男子の世界記録に対する女子のそれの比率は, 競泳の場合には競走の場合より大きいが, この差は女子の体脂肪の多いことが水泳では有利に作用していることに由来するものと考えられる。Body fat lessens underwater body weight and may offer an advantage for swimming performance. The present study was undertaken to measure separately V̇O2 for buoyancy and that for propulsion during swimming in the swimming flume and to elucidate the advantage of lower underwater body weight in female. Three male swimmers and three female swimmers participated as the subjects. V̇O2 was measured during free style swimming at a constant speed of 0.6, 0.8 and l.0m/sec.Underwater weight was increased stepwisely by loading an extra-weight around the subject's waist or decreased by suspending a weight which pulls the waist upward via a wire and pulleies. V̇O2 at a given speed depended proportionally on the underwater weight. V̇O2 for propu1sion was estimated by subtracting resting V̇O2 from the intercept on the ordinate, and V̇O2 for buoyancy was calculated from the slope. 1) V̇O2 for buoyancy was independent of swimming speed and the average value for female swimmers was much smaller than that for male swimmers (352±140m1/min for male, 186±83m1/min for female). This difference in V̇O2 for buoyancy depended largely on the difference in underwater weight as the calculated values of V̇O2 for buoyancy per kg of underwater weight revealed much smaller difference between sexes (117±46m1/min for male, 91±36m1/min for female). 2) V̇O2 for propulsion increased exponentially with increasing speed. The increasing rate was larger in female than in male. This is probably because of relative inferiority of swimming ability in the female group in this study. 3) The rate of propulsion V̇O2 to total V̇O2 during swimming was larger in female than in male. This represents the advantage of lower underwater weight in female for swimming. This result offers the probable explanation for the discrepancy which exists in male-female ratio of the world records between swimming and running

Selective Cyclooxygenase-2 Inhibitor Prevents Cisplatin-induced Tumorigenesis in A/J Mice

Cisplatin is used to treat lung cancer;however, it is also a known carcinogen. Cyclooxygenase-2 (COX-2) inhibitors have been shown to prevent carcinogen-induced experimental tumors. We investigated the effect of a COX-2 inhibitor, celecoxib, on cisplatin-induced lung tumors. One hundred twenty 4-week-old A/J mice were divided into 6 groups:group 1, no treatment;group 2, low-dose celecoxib (150mg/kg);group 3, high-dose celecoxib (1,500mg/kg);group 4, cisplatin alone;group 5, cisplatin plus low-dose celecoxib;and group 6, cisplatin plus high-dose celecoxib. Mice in groups 4-6 were administered cisplatin (1.62mg/kg, i.p.) once a week for 10 weeks between 7 and 16 weeks of age. All mice were sacrificed at week 30. Tumor incidence was 15.8% in group 1, 25% in group 2, 26.3% in group 3, 60% in group 4, 50% in group 5, and 50% in group 6. Tumor multiplicity was 0.2, 0.3, 0.3, 1.3, 1.0, and 0.6 in groups 1-6, respectively. Tumor multiplicity in the cisplatin-treated mice was reduced by celecoxib treatment in a dose-dependent manner (p＜0.05, group 4 vs. group 6). Celecoxib significantly reduced COX-2 expression in cisplatin-induced tumors (p＜0.01, group 4 vs. group 6)

Nintedanib can be used safely and effectively for idiopathic pulmonary fibrosis with predicted forced vital capacity <= 50%: A multi-center retrospective analysis

Background Nintedanib is a multi-kinase inhibitor approved for idiopathic pulmonary fibrosis (IPF); however, its efficacy and safety for patients with IPF and restricted pulmonary function remain unclear. Therefore, the objective of this study was to determine the efficacy and safety of nintedanib for patients with IPF and forced vital capacity (FVC) ≤ 50%. Methods This was a multi-center retrospective study performed by the Okayama Respiratory Disease Study Group. Patients were allocated into FVC ≤ 50% and FVC > 50% groups based on their predicted FVC. The primary endpoints were FVC changes from baseline after 6 and 12 months. Results 45 patients were eligible for the study. 18 patients had FVC ≤ 50%, and 27 patients had FVC > 50%. Overall, 31 and 19 patients underwent pulmonary function tests at 6 and 12 months after initiating nintedanib, respectively. FVC changes from baseline at 6 and 12 months after initiating nintedanib were comparable between the two groups. Adverse events were seen in all patients, and the rates of patients who discontinued nintedanib were also comparable (38.9% vs. 37.0%, p = 1.000). Multiple regression analysis showed that age and forced expiratory volume in 1 second (FEV1)/FVC were negatively correlated with changes in FVC at 6 months after initiating nintedanib. Conclusions Our data suggest that nintedanib can be a useful agent for IPF patients, including those with a low FVC, and that age and FEV1/FVC are predictive markers for changes in FVC following nintedanib treatment

Nintedanib can be used safely and effectively for idiopathic pulmonary fibrosis with predicted forced vital capacity <= 50%: A multi-center retrospective analysis

Background Nintedanib is a multi-kinase inhibitor approved for idiopathic pulmonary fibrosis (IPF); however, its efficacy and safety for patients with IPF and restricted pulmonary function remain unclear. Therefore, the objective of this study was to determine the efficacy and safety of nintedanib for patients with IPF and forced vital capacity (FVC) ≤ 50%. Methods This was a multi-center retrospective study performed by the Okayama Respiratory Disease Study Group. Patients were allocated into FVC ≤ 50% and FVC > 50% groups based on their predicted FVC. The primary endpoints were FVC changes from baseline after 6 and 12 months. Results 45 patients were eligible for the study. 18 patients had FVC ≤ 50%, and 27 patients had FVC > 50%. Overall, 31 and 19 patients underwent pulmonary function tests at 6 and 12 months after initiating nintedanib, respectively. FVC changes from baseline at 6 and 12 months after initiating nintedanib were comparable between the two groups. Adverse events were seen in all patients, and the rates of patients who discontinued nintedanib were also comparable (38.9% vs. 37.0%, p = 1.000). Multiple regression analysis showed that age and forced expiratory volume in 1 second (FEV1)/FVC were negatively correlated with changes in FVC at 6 months after initiating nintedanib. Conclusions Our data suggest that nintedanib can be a useful agent for IPF patients, including those with a low FVC, and that age and FEV1/FVC are predictive markers for changes in FVC following nintedanib treatment