A BIOMECHANICAL ANALYSIS OF COMPETITIVE AND RECREATIONAL PLAYERS IN RELATION TO THE DARTS THROWING TECHNIQUE

The aim of this study was to clarify the difference of the darts throwing motion (technique) between competitive (CG) and recreational (RG) groups. The darts throwing motions for each group were analyzed using an automatic motion capture system and force platforms. The performance (distance) of CG was statistically superior to RG. Shoulder and elbow joint movement indexes were smaller in CG than in RG. CG threw the dart with the static position that body weight was mostly distributed to the forward leg. However, RG started from the static position that distributed two thirds of body weight on the forward leg, and subsequently threw the dart while transmitting most of the remaining body weight from backward leg to forward leg. It is concluded that CG had the less movement of body segments involved in the darts throwing motion to achieve a high level of performance

A BIOMECHANICAL COMPARISON OF THE CROSSOVER STEP AND JAB STEP TECHNIQUES IN THE PUSHOFF OF BASE STEALING STARTS IN BASEBALL

The aim of this study was to compare the effectiveness of the crossover step (CS) and jab step (JS) start techniques in baseball base stealing. Fourteen varsity fielders participated in the study. An automatic motion capture system and synchronized force platforms were used to analyze the two start techniques, performed at full effort by each individual. No statistical difference was found in the start time (duration of the start phase) between the two techniques. However, the start velocity (forward velocity of the body CG at the end of right leg push-off phase) was significantly larger in JS than in CS. It was found that the difference in the start velocity between the two step techniques comes from the difference in the forward impulse generated by the left leg push-off

A BIOMECHANICAL STUDY OF TIMING IN BASEBALL BATTING AGAINST A PITCHED FASTBALL: COMPARISON OF BATTING SITUATIONS WITH AND WITHOUT PRIOR KNOWLEDGE OF THE TYPE OF PITCH

The aim of the study was to examine the differences in the timing of the batting motion between a situation in which the batter knew beforehand the type of incoming pitch and a situation in which he did not. Nine pitchers and 9 batters participated in this study. Batters were requested to hit the pitched ball in known-pitch and unknown-pitch situations. A successful trial of the batter was one in which the ball was hit squarely; a failed trial was one that produced a glancing blow. Pitching and batting motions were recorded with video cameras and a motion capture system. In the known-pitch situation, significant positive correlations were found between four batting phases and three pitching phases. The results suggested that the timing strategy of the batting motion in the unknown situation is different from that of the known situation

A KINEMATIC COMPARISON OF THE DELIVERY MOTIONS OF CATCHERS AND INFIELDERS IN BASEBALL

The aim of this study was to compare the delivery motions of baseball catchers and infielders. Thirteen catchers and 16 infielders participated in the study. 3D analysis was used to analyze the release parameters, the durations of 4 phases, and trunk, pelvis and throwing arm kinematics in the two groups. No statistical difference in ball velocity and angle of release was found between the groups. Of the 45 angular position and angular velocity parameters tested at key instants in the throws, 15 showed significant differences between the groups. The only significant differences in maximum angular velocities and in their times of occurrence were in the maximum pelvis forward rotation angular velocity and in the time of occurrence of the maximum elbow extension angular velocity. These results should be useful for the improvement of baseball throwing motions

Successful Treatment of Tracheal Stenosis with Slide Tracheoplasty after the Failure of Resection with End-to-End Anastomosis

The combined effects of inhaled irritant gases and heat in burn patients can result in the development of laryngotracheal strictures. Several factors could adversely affect the development of tracheal stenosis and cause the growth of granulation tissue. Yet the current treatment options for this condition are limited because of the paucity of case reports. We report here on a case of a patient who experienced recurrent upper tracheal stenosis after an inhalation injury. She displayed repetitive symptoms of stenosis even after several laryngomicrosurgeries and resection with end-to-end anastomosis. Finally, 5 yr after the burn injury, slide tracheoplasty was successfully performed and the postoperative check-up findings and the increased airway volume seen on imaging were all satisfactory

TAK1 inhibition in myeloma

Along with the tumor progression, the bone marrow microenvironment is skewed in multiple myeloma (MM), which underlies the unique pathophysiology of MM and confers aggressiveness and drug resistance in MM cells. TGF-β-activated kinase-1 (TAK1) mediates a wide range of intracellular signaling pathways. We demonstrate here that TAK1 is constitutively overexpressed and phosphorylated in MM cells, and that TAK1 inhibition suppresses the activation of NF-κB, p38MAPK, ERK and STAT3 in order to decrease the expression of critical mediators for MM growth and survival, including PIM2, MYC, Mcl-1, IRF4, and Sp1, along with a substantial reduction in the angiogenic factor VEGF in MM cells. Intriguingly, TAK1 phosphorylation was also induced along with upregulation of vascular cell adhesion molecule-1 (VCAM-1) in bone marrow stromal cells (BMSC) in cocultures with MM cells, which facilitated MM cell-BMSC adhesion while inducing IL-6 production and receptor activator of nuclear factor κ-Β ligand (RANKL) expression by BMSC. TAK1 inhibition effectively impaired MM cell adhesion to BMSC to disrupt the support of MM cell growth and survival by BMSC. Furthermore, TAK1 inhibition suppressed osteoclastogenesis enhanced by RANKL in cocultures of bone marrow cells with MM cells, and restored osteoblastic differentiation suppressed by MM cells or inhibitory factors for osteoblastogenesis overproduced in MM. Finally, treatment with the TAK1 inhibitor LLZ1640-2 markedly suppressed MM tumor growth and prevented bone destruction and loss in mouse MM models. Therefore, TAK1 inhibition may be a promising therapeutic option targeting not only MM cells but also the skewed bone marrow microenvironment in MM

キサンチンオキシダーゼ阻害薬febuxostatはNrf2を活性化し脂肪細胞分化を抑制する

Xanthine oxidoreductase (XOR) is a rate-limiting enzyme in purine catabolism that acts as a novel regulator of adipogenesis. In pathological states, xanthine oxidoreductase activity increases to produce excess reactive oxygen species (ROS). The nuclear factor erythroid 2-related factor 2 (Nrf2) is a critical inducer of antioxidants, which is bound and repressed by a kelch-like ECH-associated protein 1 (Keap1) in the cytoplasm. The Keap1-Nrf2 axis appears to be a major mechanism for robust inducible antioxidant defenses. Here, we demonstrate that febuxostat, a xanthine oxidase inhibitor, alleviates the increase in adipose tissue mass in obese mouse models with a high-fat diet or ovariectomy. Febuxostat disrupts in vitro adipocytic differentiation in adipogenic media. Adipocytes appeared at day 7 in absence or presence of febuxostat were 160.8 ± 21.2 vs. 52.5 ± 12.7 (p < 0.01) in 3T3–L1 cells, and 126.0 ± 18.7 vs. 55.3 ± 13.4 (p < 0.01) in 10T1/2 cells, respectively. Adipocyte differentiation was further enhanced by the addition of hydrogen peroxide, which was also suppressed by febuxostat. Interestingly, febuxostat, but not allopurinol (another xanthine oxidase inhibitor), rapidly induced the nuclear translocation of Nrf2 and facilitated the degradation of Keap1, similar to the electrophilic Nrf2 activator omaveloxolone. These results suggest that febuxostat alleviates adipogenesis under oxidative conditions, at least in part by suppressing ROS production and Nrf2 activation. Regulation of adipocytic differentiation by febuxostat is expected to inhibit obesity due to menopause or overeating