643 research outputs found

    ANALYSIS OF THE SERVING MOTION OF MALE COLLEGE TENNIS PLAYERS IN A SIMULATED MATCHES

    Get PDF
    The purpose of this study was to analyse the serving motion of the nineteen male college tennis players in simulated matches, and to seek for critical points for the improvement in the techniques by comparing with that of the world-class players reported by Fleisig et al. (2003) and Michikami (2014). The variables used in this study were the ball speed, racket speed, angles and angular velocities of the upper and lower limbs. Ball speed and racket speed for the male college players were significantly lower than that of the world-class players. The peak angular velocities of the right shoulder internal rotation and the left knee extension were lower in the male college players than those of the world-class players. For the improvement in the ball speed in serve, the critical points identified would be large angular velocities of the shoulder internal rotation and the knee extension

    ANALYSIS OF RUNNING MOTION IN THE STARTING PHASE OF MALE SKELETON ATHLETES AT INTERNATIONAL COMPETITIONS

    Get PDF
    The purpose of this research was to assess which kinematic factors were related to running speed in the starting phase for international-level skeleton athletes during races. The starting motion of 22 male athletes was recorded with four video cameras during competitions and their starting motion was analysed by a three-dimensional direct linear transformation method. The maximum angular velocity of the thigh increased from the 2nd to the 3rd step. The maximum hip extension angular velocity of the support leg gradually increased up until the 6th step while the maximum knee extension angular velocity remained constant throughout. It would appear that international-level male skeleton athletes employed an increase in thigh motion and quick hip and knee extension for the support leg to obtain a large running speed

    A CASE STUDY OF THE GENERATION OF ANGULAR MOMENTUM AND ANGULAR VELOCITY IN SOMERSAULT BACKWARD STRETCHED WITH 2/1 AND 3/1 TWISTS PERFORMED BY A SINGLE VARSITY MALE GYMNAST

    Get PDF
    The purpose of this study was to compare the angular momentum and angular velocity in somersault backward stretched with different number of twists performed by a single varsity male gymnast. The 3D motion captured system (Qualisys, 250Hz) was used to collect kinematic data of a single varsity male gymnast A who performed the somersault backward stretched with a double (2/1) and a triple (3/1) twist. The angular momenta and angular velocities of the body segments and whole body were calculated by the Tang’s method. More than a half of the twist angular momentum of the whole body in both 2/1 and 3/1 twists was generated during the take-off phase, which indicated that the gymnast A was classified as a contact twist type. In case of the gymnast A there seemed no difference in angular momenta of 2/1 and 3/1 twists, although he generated the angular momentum of the twist earlier in 3/1 than 2/1. He controlled the number of twists by his body maneuver before landing. Since these findings were obtained from a single gymnast, we need to investigate twist techniques and angular momentum date of various gymnasts

    THE STANDARD MOTION MODEL OF A BASKETBALL SET SHOT FOR TEACHING

    Get PDF
    The purpose of this study was to create a standard motion model of a basketball set shot. Twenty-one male collegiate basketball players participated in three-dimensional data collection session (Vicon MX+, 250Hz), and the method proposed by Ae, et al. (2007) was used to create a standard motion model. The set shot motion in the standard motion model started with the shoulder flexion and hip extension in the downward phase, followed by the sequential motions of the knee, ankle, shoulder, elbow and wrist joints in the upward phase. Immediately before the ball release, the elbow and wrist joints were abruptly extended. The motion variation in the wrist, elbow and shoulder joints just before the ball release were small, implying there must be some commonality in these joint motions

    Activation of fibroblast-like synoviocytes derived from rheumatoid arthritis via lysophosphatidic acid-lysophosphatidic acid receptor 1 cascade

    Get PDF
    INTRODUCTION: Lysophosphatidic acid (LPA) is a bioactive lipid that binds to G protein–coupled receptors (LPA(1–6)). Recently, we reported that abrogation of LPA receptor 1 (LPA(1)) ameliorated murine collagen-induced arthritis, probably via inhibition of inflammatory cell migration, Th17 differentiation and osteoclastogenesis. In this study, we examined the importance of the LPA–LPA(1) axis in cell proliferation, cytokine/chemokine production and lymphocyte transmigration in fibroblast-like synoviocytes (FLSs) obtained from the synovial tissues of rheumatoid arthritis (RA) patients. METHODS: FLSs were prepared from synovial tissues of RA patients. Expression of LPA(1–6) was examined by quantitative real-time RT-PCR. Cell surface LPA(1) expression was analyzed by flow cytometry. Cell proliferation was analyzed using a cell-counting kit. Production of interleukin 6 (IL-6), vascular endothelial growth factor (VEGF), chemokine (C-C motif) ligand 2 (CCL2), metalloproteinase 3 (MMP-3) and chemokine (C-X-C motif) ligand 12 (CXCL12) was measured by enzyme-linked immunosorbent assay. Pseudoemperipolesis was evaluated using a coculture of RA FLSs and T or B cells. Cell motility was examined by scrape motility assay. Expression of adhesion molecules was determined by flow cytometry. RESULTS: The expression of LPA(1) mRNA and cell surface LPA(1) was higher in RA FLSs than in FLSs from osteoarthritis tissue. Stimulation with LPA enhanced the proliferation of RA FLSs and the production of IL-6, VEGF, CCL2 and MMP-3 by FLSs, which were suppressed by an LPA(1) inhibitor (LA-01). Ki16425, another LPA(1) antagonist, also suppressed IL-6 production by LPA-stimulated RA FLSs. However, the production of CXCL12 was not altered by stimulation with LPA. LPA induced the pseudoemperipolesis of T and B cells cocultured with RA FLSs, which was suppressed by LPA(1) inhibition. In addition, LPA enhanced the migration of RA FLSs and expression of vascular cell adhesion molecule and intercellular adhesion molecule on RA FLSs, which were also inhibited by an LPA(1) antagonist. CONCLUSIONS: Collectively, these results indicate that LPA–LPA(1) signaling contributes to the activation of RA FLSs

    Japan College of Rheumatology 2009 guidelines for the use of tocilizumab, a humanized anti-interleukin-6 receptor monoclonal antibody, in rheumatoid arthritis

    Get PDF
    The introduction of biological agents targeting tumor necrosis factor-alpha (TNF-α) has brought about a paradigm shift in the treatment of rheumatoid arthritis (RA). Although these anti-TNF agents have excellent efficacy against RA, a substantial number of patients still show inadequate responses. In Western countries, such patients are already being treated with new classes of antirheumatic drugs such as abatacept and rituximab. Tocilizumab (TCZ) is a humanized monoclonal antibody developed in Japan against the human interleukin-6 (IL-6) receptor. TCZ does not only alleviate the signs and symptoms of RA but also seems to prevent progressive bone and joint destruction. However, there is a concern that TCZ might increase the risk of adverse events such as infections since IL-6 plays a pivotal role in the immune system. Calculating the relative risks of specific adverse outcomes with TCZ use remains difficult, due to insufficient patient numbers enrolled in clinical trials to date. This review presents tentative guidelines for the use of TCZ for RA patients prepared by the Japan College of Rheumatology and based on results of clinical trials in Japan and Western countries. The guidelines are intended as a guide for postmarketing surveillance and clinical practice, and will be revised periodically based on the surveillance

    Postmarketing surveillance of safety and effectiveness of etanercept in Japanese patients with rheumatoid arthritis

    Get PDF
    Our aim was to evaluate real-world safety and effectiveness in a 6-month postmarketing surveillance study covering all Japanese patients with rheumatoid arthritis (RA) who received etanercept during a 2-year period. Data for 13,894 patients (1334 sites) enrolled between March 2005 and April 2007 were collected. Adverse events (AEs) and serious adverse events (SAEs) were reported in 4336 (31.2%) and 857 (6.2%) patients, respectively. The most frequent AEs were injection site reactions (n = 610, 4.4%) and rash (n = 339, 2.4%), whereas pneumonia (n = 116, 0.8%) and interstitial lung disease (n = 77, 0.6%) were the most frequent SAEs. Significant improvement in the proportion of patients with a good European League Against Rheumatism (EULAR) response was observed from week 4 (17.6%) to week 24 (31.6%) (p < 0.001); 84.3% of patients had good or moderate EULAR responses at week 24. The percentage of patients achieving remission increased significantly from week 4 (9.3%) to week 24 (18.9%) (p < 0.001). Patients with early moderate RA were less likely to experience SAEs and were more likely to achieve remission compared with patients with more severe disease. The safety and effectiveness of etanercept was demonstrated in Japanese patients in one of the largest observational trials conducted thus far in RA patients treated with biologics

    Expression and function of inducible co-stimulator in patients with systemic lupus erythematosus: possible involvement in excessive interferon-γ and anti-double-stranded DNA antibody production

    Get PDF
    Inducible co-stimulator (ICOS) is the third member of the CD28/cytotoxic T-lymphocyte associated antigen-4 family and is involved in the proliferation and activation of T cells. A detailed functional analysis of ICOS on peripheral blood T cells from patients with systemic lupus erythematosus (SLE) has not yet been reported. In the present study we developed a fully human anti-human ICOS mAb (JTA009) with high avidity and investigated the immunopathological roles of ICOS in SLE. JTA009 exhibited higher avidity for ICOS than a previously reported mAb, namely SA12. Using JTA009, ICOS was detected in a substantial proportion of unstimulated peripheral blood T cells from both normal control individuals and patients with SLE. In CD4(+)CD45RO(+ )T cells from peripheral blood, the percentage of ICOS(+ )cells and mean fluorescence intensity with JTA009 were significantly higher in active SLE than in inactive SLE or in normal control individuals. JTA009 co-stimulated peripheral blood T cells in the presence of suboptimal concentrations of anti-CD3 mAb. Median values of [(3)H]thymidine incorporation were higher in SLE T cells with ICOS co-stimulation than in normal T cells, and the difference between inactive SLE patients and normal control individuals achieved statistical significance. ICOS co-stimulation significantly increased the production of IFN-γ, IL-4 and IL-10 in both SLE and normal T cells. IFN-γ in the culture supernatants of both active and inactive SLE T cells with ICOS co-stimulation was significantly higher than in normal control T cells. Finally, SLE T cells with ICOS co-stimulation selectively and significantly enhanced the production of IgG anti-double-stranded DNA antibodies by autologous B cells. These findings suggest that ICOS is involved in abnormal T cell activation in SLE, and that blockade of the interaction between ICOS and its receptor may have therapeutic value in the treatment of this intractable disease
    corecore