Relationship of Clubhead Speed With Explosive Power and Muscle Strength of the Hip and Trunk Joints of Elite Golfers

ABSTRACT

Suhara, H, Nariai, M, Takagi, T, Akiyama, K, Nagashima, J, and Shiraki, H. Relationship of clubhead speed with explosive power and muscle strength of the hip and trunk joints of elite golfers. J Strength Cond Res 37(4): 859-865, 2023-In golf, the driving distance of the ball is affected by the clubhead speed (CHS) on impact. We aimed to clarify the relationship between CHS and explosive power and muscle strength of the hip and trunk muscles in elite golfers (male age: 19.6 ± 1.9 years, male handicap: 4.4 ± 0.9, female age: 17.7 ± 1.4 years, and female handicap: 6.2 ± 0.7). A correlational design was used to assess the relationships between CHS and strength (hip extension-flexion and trunk rotation of peak torque at an isokinetic 60 and 180°·s -1 angular velocity) and CHS and power (countermovement jump [CMJ]; peak power and jump height; backward overhead medicine ball [BOMB] throw). Fourteen each of male and female elite golfers were included. The CHS during the golf swing was measured using a Doppler radar measurement device (Trackman). A correlation analysis between each measurement and CHS ( p ≤ 0.05) was conducted. We found that the peak torque of right hip extension at an angular velocity of 180°/s (male, r = 0.67; female, r = 0.61), peak CMJ power (male: r = 0.63, female: r = 0.75), and BOMB throw distance (male, r = 0.6; female, 0.6) were positively correlated with CHS in both male and female golfers. These results suggest that the extensor strength of the lower extremities and trunk, centered on the hip joint in the sagittal plane, is important for physical fitness and muscle strength measurement related to CHS. Conversely, concentric trunk rotator strength and CHS were not correlated, suggesting that concentric trunk rotator strength may not be actively involved in CHS.

Factors Associated with the Prevalence and Severity of Menstrual-Related Symptoms: A Systematic Review and Meta-Analysis

This study aimed to identify factors associated with the prevalence and severity of menstrual-related symptoms. The protocol was registered in PROSPERO (CRD42021208432). We conducted literature searches of PubMed and Ichushi-Web and used the Jonna Briggs Institute critical appraisal checklist to assess the quality. Of the 77 studies included in the meta-analysis, significant odds ratios (ORs) were obtained for eight factors associated with primary dysmenorrhea (PD): age ≥ 20 years (OR: 1.18; 95% confidence interval [CI]: 1.04−1.34), body mass index (BMI) < 18.5 kg/m2 (OR: 1.51; 95% CI: 1.01−2.26), longer menstrual periods (OR: 0.16; 95% CI: 0.04−0.28), irregular menstrual cycle (OR: 1.28; 95% CI: 1.13−1.45), family history of PD (OR: 3.80; 95% CI: 2.18−6.61), stress (OR: 1.88; 95% CI: 1.30−2.72), sleeping hours < 7 h (OR: 1.19; 95% CI: 1.04−1.35), and bedtime after 23:01 (OR: 1.30; 95% CI: 1.16−1.45). Two factors were associated with severity of PD (moderate vs. severe): BMI < 18.5 kg/m2 (OR: 1.89; 95% CI: 1.01−3.54) and smoking (OR: 1.94; 95% CI: 1.08−3.47). PD severity (mild vs. severe) and prevalence of premenstrual syndrome were associated with BMI < 18.5 kg/m2 (OR: 1.91; 95% CI: 1.04−3.50) and smoking (OR: 1.86; 95% CI: 1.31−2.66), respectively. The identified risk factors could be utilized to construct an appropriate strategy to improve menstrual symptoms and support women’s health.

The Effects of a Medial Heel Wedge on the Weight-Bearing Response of Hindfoot Valgus and the Total Weight-Bearing Responses of the Navicular and Talus Bones

OBJECTIVES Medial heel wedges are commonly prescribed to manage the weight-bearing response of hindfoot valgus and the total weight-bearing responses of the navicular and talus bones. Previous studies have reported that a medial heel wedge is effective in the management of musculoskeletal injuries. However, it remains unclear the effect of a medial heel wedge on the weight-bearing responses of footarch bones in vivo. To clarify the effects of a medial heel wedge on the weight-bearing response of hindfoot valgus and the total weight-bearing responses of the navicular and talus bones is necessary to understand how best to treat musculoskeletal injuries clinically. The purpose of our study was to clarify the effects of a medial heel wedge on the weight-bearing response of hindfoot valgus and the total weight-bearing responses of the navicular and talus bones.METHODS Twenty-five healthy males were analyzed. We obtained MRI scanning of the right foot under non-loading (NL) and full weight-bearing (FW) conditions. Participants wore two insole types, a flat insole and a medial heel wedge. To evaluate the weight-bearing response in hindfoot valgus, the hindfoot alignment view (HAV) was measured. We also measured navicular and talus bone positions and calculated the total positional changes of the navicular and talus bones (ΔTPCN, ΔTPCT) from the vertical and medial displacements using the Pythagorean theorem.RESULTS Significant interactions were observed with the HAV. Under both NL and FW conditions, the HAV was smaller on the medial heel wedge than on the flat insole. In addition, the ΔTPCN was significantly smaller on the medial heel wedge than on the flat insole. However, no significant differences were observed for ΔTPCT.CONCLUSIONS Our results suggest that use of a medial heel wedge decreases hindfoot valgus values under both NL and FW conditions and stabilizes the total weight-bearing response of the navicular bone.

Effect of temporary school closure due to COVID-19 on musculoskeletal function in elementary school children

Objective: In 2020, coronavirus disease-2019 (COVID-19) became the cause of a pandemic. In response, the Japan Sports Agency issued warnings about secondary damage to health, such as the threat to physical and mental well-being due to the lack of exercise in this situation. In this study, we report on cross-sectional and longitudinal examinations of standing trunk flexion to evaluate how temporary long-term school closures affected musculoskeletal function in elementary school students. Patients and Methods: All children in one public elementary school in T-city during the school years 2019 and 2020 were included in this study. A digital forward flexion meter was used to measure standing trunk flexion. Results: In this study, 284 (284/289: 98.3%) and 266 (266/274: 97.1%) children in school years 2020 and 2019, respectively, were found to have valid data for cross-sectional analysis. The standing trunk flexion did not show significant differences between grades or sexes. In the longitudinal analysis, the results of the comparison of standing trunk flexion in children for two consecutive years revealed significant differences only between grades 3 and 4 (P<0.05) and between girls in grades 3 and 4 (P<0.01), but no significant differences in other grades or among boys or girls were observed. Conclusion: Initially, we expected that there would be a difference in the results of functional assessment using standing trunk flexion depending on the period of absence from school. However, the results of this study showed no significant changes in standing trunk flexion. Moreover, since children's musculoskeletal functions may be affected by various factors during the COVID-19 pandemic, they should be carefully monitored in the future.

Preload stress echocardiography by using dynamic postural alteration can identify high risk patients with heart failure with reduced ejection fraction

Funding Acknowledgements

Type of funding sources: None.

Background

Haemodynamic assessment during stress testing is not commonly performed for patients with heart failure with reduced ejection fraction (HFrEF) due to its invasiveness, less feasibility, and safety concerns. Passive leg-lifting (PLL) manoeuvres have been introduced as a simple alternative for non-invasive preload stress testing; however, the haemodynamic load imposed on the cardiovascular system is unsatisfactory, which precludes the accurate assessment of the preload reserve for patients with HF.

Purpose

The purpose of this study was to assess the haemodynamic characteristics of patients with HFrEF in response to a preload stress during dynamic postural alterations by combining the semi-sitting position (SSP) and PLL. We also evaluated whether combined postural stress could be used for risk stratification for these patients.

Methods

For this study, 101 patients with HFrEF and 35 age- and sex-matched normal controls were prospectively recruited. At each postural position (i.e., baseline, SSP, and PLL), all standard echocardiographic and Doppler variables were obtained. Adverse cardiac events were prespecified as the combined endpoints of death from or hospitalisation for deteriorated HF, or sudden cardiac death. Clinical follow-up was conducted for a median of 7 months.

Results

During PLL stress, the stroke volume index (SVi) significantly increased in both controls (from 40 ± 6 to 43 ± 6 mL/m², P = 0.03) and HFrEF patients (from 31 ± 9 to 34 ± 10 mL/m², P = 0.03). Conversely, during SSP stress, the SVi significantly decreased for both controls (from 40 ± 6 to 37 ± 6 mL/m², P = 0.03) and HFrEF patients (31 ± 9 to 28 ± 8 mL/m², P = 0.03). During the follow-up period, 16 patients developed cardiac events. In patients without events, the Frank-Starling mechanism was well preserved (Fig. A). Namely, the SVi significantly increased from 31 ± 9 to 35 ± 10 mL/m² (P = 0.02) during PLL stress, while the SVi significantly decreased from 31 ± 8 to 28 ± 8 mL/m² (P = 0.02) during SSP stress. In contrast, for patients with cardiac events, the SVi did not change during postural alterations (n.s), which indicated that the failing heart operates on the flat portion of the Frank-Starling curve (Fig. A). When patients were divided into three equal sub-groups based on the total difference in the SVi during dynamic postural stress, patients with impaired preload reserve (third trimester, ΔSVi ≤ 3.0 mL/m²) showed significantly worse event-free survival than the other two sub-groups (Fig. B; P &lt; 0.001). In a Cox proportional-hazard analysis, baseline LVEF (hazard ratio 0.93; P = 0.04), and ΔSVi during postural stress (hazard ratio 0.76; P = 0.004) were predictors of future cardiac events.

Conclusions

The combined assessment of dynamic postural stress during PLL and SPP is a simple, time-saving, and easy-to-use clinical tool for the assessment of preload reserve for patients with HFrEF. Moreover, postural stress echocardiography proved to contribute to the risk stratification for these patients.

Abstract Figure.

Consideration of non-valvular atrial fibrillation with left atrial appendage thrombus formation despite under appropriate oral anticoagulation therapy

Background

Atrial fibrillation (AF) is the most frequently sustained cardiac arrhythmia, with a prevalence of about 2–3% in the general population. In accordance with CHADS2 or CHA2DS2-VASc score, appropriate oral anticoagulation therapy such as warfarin or direct oral anticoagulants (DOAC) significantly reduced the risk of thromboembolic events. However, left atrial (LA) thrombus can be detected in the LA appendage (LAA) in AF patients despite appropriate oral anticoagulation therapy.

Purpose

Our purpose was to investigate the associated factors of LAA thrombus formation in non-valvular atrial fibrillation (NVAF) patients despite under appropriate oral anticoagulation therapy.

Methods

We retrospectively studied consecutive 286 NVAF patients for scheduled catheter ablation or electrical cardioversion for AF in our institution between February 2017 and September 2019. Mean age was 67.1±9.4 years, 79 patients (29.5%) were female, and 140 (52.2%) were paroxysmal AF. All patients underwent transthoracic and transesophageal echocardiography before catheter ablation or electrical cardioversion. All patients received appropriate oral anticoagulation therapy including warfarin or DOAC for at least 3 weeks prior to transesophageal echocardiography based on the current guidelines. LAA thrombus was defined as an echodense intracavitary mass distinct from the underlying endocardium and not caused by pectinate muscles by at least three senior echocardiologists.

Results

Of 286 NVAF patients with under appropriate oral anticoagulation therapy, LAA thrombus was observed in 9 patients (3.3%). Univariate logistic regression analysis showed that age, paroxysmal AF, CHADS2 score ≥3, left ventricular end-diastolic volume index (LVEDVI), left ventricular ejection fraction (LVEF), left ventricular mass index (LVMI), LA volume index (LAVI), mitral inflow E and mitral e' annular velocities ratio (E/e'), and LAA flow were associated with LAA thrombus formation. It was noteworthy that multivariate logistic regression analysis showed that LAA flow was independent predictor of LAA thrombus (OR: 0.72, 95% CI: 0.59–0.89, p&lt;0.005) as well as LVEF. Furthermore, receiver operating characteristic (ROC) curve analysis identified the optimal cutoff value of LAA flow for predicting LAA thrombus as ≤15cm/s, with a sensitivity of 88%, specificity of 93%, and area under the curve (AUC) of 0.95.

Conclusions

LAA flow was strongly associated with LAA thrombus formation even in NVAF patients with appropriate oral anticoagulation therapy. According to our findings, further strengthen of oral anticoagulation therapy or percutaneous transcatheter closure of the LAA may be considered in NVAF patients with appropriate oral anticoagulation therapy but low LAA flow, especially &lt;15cm/s.

Funding Acknowledgement

Type of funding source: None

Dynamics of pelvis rotation about its longitudinal axis during the golf swing

The purpose of this study was to identify the dynamic factors contributing to pelvis angular velocity about its longitudinal axis (pelvis axial angular velocity) during the golf swing. Thirty-one right-handed skilled golfers (handicap, 3.5 ± 1.8) performed swings with a driver. The kinematic and kinetic data were collected using an optical motion analysis system and two force platforms. The dynamic factors (i.e., joint torque, gravitational force, motion-dependent forces and inertia forces) contributing to pelvis axial angular acceleration were calculated. The present study revealed that the left (lead) hip flexor and adductor torques as well as the right (trail) hip extensor and abductor torques were identified as the main contributors to pelvis axial angular velocity. These hip joint torques contributed not synchronously but sequentially to the pelvis. Although the knee joint torques contributed little to pelvis axial angular velocity directly, the knee joint torques might support the generation of large hip joint torques by regulating joint postures. These findings indicate that the functional coordination of the lower limb segments as well as the magnitude of the joint torques play an important role in rotating the pelvis.

Risk of female athlete triad development in Japanese collegiate athletes is related to sport type and competitive level

Introduction

Menstrual dysfunction, musculoskeletal injury, and poor nutrition combine to form the female athlete triad (FAT), which results in serious health consequences for affected athletes. To this point, the risk factors of this phenomenon have not been fully explored in Japanese female college athletes. Additionally, the effect of competitive level on FAT risk factors has also not been reported. Therefore, we aimed to examine FAT risk factors in Japanese female athletes of various sports as well as examine the impact of competitive level on FAT.

Methods

A Japanese-language survey was completed by 531 athletes and 20 nonathletes at two Japanese universities and answers with regard to menstrual status, musculoskeletal injury, nutrition, and other variables were analyzed based on classification of the sports into nine distinct groups based on activity type. Sport intensity, training volume, and competitive levels were used to further classify each sport. One-way ANOVA and the Bonferroni post hoc test using SPSS were carried out to analyze significance for relationships between sport intensity and FAT risk factors. Additionally, the relationship between competitive level and FAT risk factors was analyzed by ANOVA and Bonferroni post hoc tests.

Results

Sport intensity was positively correlated with a delay in menarche as well as dysmenorrhea and poor nutrition while musculoskeletal injury was correlated with repetitive, high-training volume sports. Lower competitive levels increased dysmenorrhea but did not impact injury status or nutrition.

Conclusion

Sport intensity and training volume, but not competitive level, are the critical factors affecting FAT risk in Japanese female college athletes.

MRI reveals menstrually-related muscle edema that negatively affects athletic agility in young women

Context

About 10% of Japanese female athletes are afflicted by menstrually-related edema, mainly in the lower limbs, and, with few studies on this problem, the effect on performance remains unclear.

Objective

To quantitatively evaluate fluid retention in the calf in female students over their menstrual cycle using magnetic resonance imaging (MRI) and to determine the relationship of MRI changes and athletic performance.

Design

The menstrual cycle was divided into 5 phases: menstrual, follicular, ovulatory, early luteal, and late luteal with sampling done in either morning (AM) or afternoon (PM) sessions. At each phase, MRI of the calf (7:00–8:00, 14:00–16:00), body composition and hormones (7:00–8:00), and athletic performance (14:00–16:00) were evaluated.

Participants

13 adult healthy Japanese female students with eumenorrhea.

Results

Estradiol levels decreased significantly in the menstrual phase and the follicular phase compared to the early luteal phase (P = 0.001, P = 0.024 respectively). Menstrual phase estradiol levels were significantly lower compared to the ovulatory phase (P = 0.015), and the late luteal phase (P = 0.003). Progesterone levels decreased significantly in the menstrual phase and the follicular phase compared to the ovulatory phase (P = 0.012, P = 0.009 respectively), the early luteal phase (both P = 0.007), and the late luteal phase (P = 0.028, P = 0.029 respectively), and it along with a significant decrease in the ovulatory phase compared to the early luteal phase (P = 0.010). AM T2 signals were significantly lower in the menstrual phase compared to the ovulatory phase (P = 0.043) but not other phases. PM T2 signals increased significantly in the menstrual phase compared to the follicular phase (P = 0.003), ovulatory phase (P = 0.009), and the late luteal phase (P = 0.032), and the difference between the AM and PM values increased significantly in the menstrual phase compared to the other 4 phases (P<0.01). A negative correlation between fluid retention and agility was observed.

Conclusion

In female students fluid retention during the menstrual phase could be a factor that influences athletic agility.

A Biomechanical Comparison Among Three Kinds of Rebound-Type Jumps in Female Collegiate Athletes

BACKGROUND

Single-legged drop jumps (SDJ), single-legged repetitive jumps (SRJ), and single-legged side hops (SSH) are often used as plyometric training and functional performance tests. Differences in the kinetics and kinematic characteristics of lower extremity joints during these jumps are unclear.

HYPOTHESIS/PURPOSE

The purpose of this study was to investigate the joint motion and mechanical work of the takeoff leg from foot contact to foot-off during SDJ, SRJ, and SSH in the sagittal and frontal planes in female athletes. It was hypothesized that the joint motion and mechanical work of the lower extremity joints during the SDJ and SRJ would be larger than the SSH in the sagittal plane, those during the SSH would be larger than the SDJ and SRJ in the frontal plane, and during SRJ would be larger than SDJ.

STUDY DESIGN

Cross-sectional study.

METHODS

Seventeen female collegiate athletes participated and performed the SDJ (0.15-m box height), and SRJ and SSH (by crossing two lines 0.3 m apart). Three-dimensional coordinate data and ground reaction forces were collected. Contact time, jump height, jump index (i.e., the jump height divided by the contact time) of the SDJ and SRJ, and the total times of the SSH were calculated. Range of motion (ROM) from touchdown to the lowest center of mass, and the positive and negative (mechanical) work from touchdown to foot-off were analyzed.

RESULTS

There were no significant differences in jump performance variables. Compared to the SSH, the SDJ and SRJ had significantly larger ankle and knee ROM and positive and negative work at the lower extremity joints, except for positive work at the hip joint, in the sagittal plane (p < 0.05). Compared to the SDJ and SRJ, the SSH had a significantly larger ankle ROM and positive work at the knee joint in the frontal plane (p < 0.05). Compared to the SDJ, the SRJ had a significantly larger ROM and negative work at each lower extremity joint in the frontal plane (p < 0.05).

CONCLUSION

Although there were no significant differences in the jump performance variables, different characteristics of the takeoff leg ROM and mechanical work were found between three kinds of rebound-type jump tests. These findings may help clinicians choose jump methods to assess lower extremity function and to design plyometric training programs in sports and clinical fields.

LEVEL OF EVIDENCE

3b.

Relationships between clubshaft motions and clubface orientation during the golf swing

Since clubface orientation at impact affects ball direction and ball spin, the ability to control clubface orientation is one of the most important skills for golfers. This study presents a new method to describe clubface orientation as a function of the clubshaft motions (i.e., swing plane orientation, clubshaft angle in the swing plane, and clubshaft rolling angle) during a golf swing and investigates the relationships between the clubshaft motions and clubface orientation at impact. The club motion data of driver shots were collected from eight skilled golfers using a three-dimensional motion capture system. The degrees of influence of the clubshaft motions on the clubface orientation were investigated using sensitivity analysis. The sensitivity analysis revealed that the swing plane horizontal angle affected the clubface horizontal angle to an extent of 100%, that the clubshaft angle in the swing plane affected both the clubface vertical and horizontal angles to extents of 74 and 68%, respectively, and that the clubshaft rolling angle affected both the clubface vertical and horizontal angles to extents of -67 and 75%, respectively. Since the method presented here relates clubface orientation to clubshaft motions, it is useful for understanding the clubface control of a golfer.

Acute Effect of High-Intensity Eccentric Exercise on Vascular Endothelial Function in Young Men

Choi, Y, Akazawa, N, Zempo-Miyaki, A, Ra, S-G, Shiraki, H, Ajisaka, R, and Maeda, S. Acute effect of high-intensity eccentric exercise on vascular endothelial function in young men. J Strength Cond Res 30(8): 2279-2285, 2016-Increased central arterial stiffness is as an independent risk factor for cardiovascular disease. Evidence regarding the effects of high-intensity resistance exercise on vascular endothelial function and central arterial stiffness is conflicting. The purpose of this study was to examine the effects of acute high-intensity eccentric exercise on vascular endothelial function and central arterial stiffness. We evaluated the acute changes in endothelium-dependent flow-mediated dilation (FMD), low-flow-mediated constriction (L-FMC), and arterial stiffness after high-intensity eccentric exercise. Seven healthy, sedentary men (age, 24 ± 1 year) performed maximal eccentric elbow flexor exercise using their nondominant arm. Before and 45 minutes after eccentric exercise, carotid arterial compliance and brachial artery FMD and L-FMC in the nonexercised arm were measured. Carotid arterial compliance was significantly decreased, and β-stiffness index significantly increased after eccentric exercise. Brachial FMD was significantly reduced after eccentric exercise, whereas there was no significant difference in brachial L-FMC before and after eccentric exercise. A positive correlation was detected between change in arterial compliance and change in FMD (r = 0.779; p ≤ 0.05), and a negative correlation was detected between change in β-stiffness index and change in FMD (r = -0.891; p < 0.01) with eccentric exercise. In this study, acute high-intensity eccentric exercise increased central arterial stiffness; this increase was accompanied by a decrease in endothelial function caused by reduced endothelium-dependent vasodilation but not by a change in endothelium-dependent vasoconstriction.

Perception and Preference for Location in Golf Practice

Many studies of the psychological effects of physical location in small discussion groups and classrooms have indicated that seating positions in groups or classrooms are related to participation, personality, or perception. In this preliminary study, environmental perception of several positions occupied by Japanese participants and preference for location in a golf-practice situation were investigated. Analyses indicated that different positions in a group were differently perceived and that certain positions were preferred over others and the main reason for the preference was related to visibility. Such information could be useful for instructors in making a psychologically comfortable environment during golf practice.

Immediate Effects of Different Trunk Exercise Programs on Jump Performance

The aim of this study was to investigate the immediate effects of trunk stabilization exercise (SE) and conventional trunk exercise (CE) programs on jump performance. 13 adolescent male soccer players performed 2 kinds of jump testing before and immediate after 3 experimental conditions: SE, CE, and non-exercise (NE). The SE program consisted of the elbow-toe, hand-knee, and back bridge, and the CE program consisted of the sit-up, sit-up with trunk rotation and back extension. Testing of a countermovement jump (CMJ) and rebound jump (RJ) were performed to assess jump performance. Jump height of the CMJ and RJ-index, contact time, and jump height of the RJ were analyzed. The RJ index was improved significantly only after SE (p=0.017). However, contact time and jump height did not improve significantly in the SE condition. Moreover, no significant interaction or main effects of time or group were observed in the CMJ. Consequently, this study showed the different immediate effect on the RJ between the SE and CE, and suggested the possibility that the SE used in this study is useful as a warm-up program to improve the explosive movements.

Comparison of the immediate effect of different types of trunk exercise on the star excursion balance test in male adolescent soccer players

PURPOSE/BACKGROUND

Trunk exercises, such as trunk stabilization exercises (SE) and conventional trunk exercises (CE), are performed to improve static or dynamic balance. Recently, trunk exercises have also been often used as part of warm-up programs. A few studies have demonstrated the immediate effects of SE and CE on static balance. However, immediate effects on dynamic balance are not yet known. Therefore, the purpose of this study was to compare the immediate effect of SE with that of CE on the Star Excursion Balance Test (SEBT).

METHODS

Eleven adolescent male soccer players (17.9 ± 0.3 years, 168.5 ± 5.4 cm, and 60.1 ± 5.1 kg) participated in this study. A crossover design was used, and each participant completed three kinds of testing sessions: SE, CE, and non-exercise (NE). Experiments took place for three weeks with three testing sessions, and a 1-week interval was provided between different conditions. Each testing session consisted of three steps: pretest, intervention, and posttest. To assess dynamic balance, the SEBT score in the anterior, posteromedial, and posterolateral directions was measured before and 5 minutes after each intervention program. The data of reach distance were normalized with the leg length to exclude the influence of the leg length on the analysis.

RESULTS

The SEBT composite score was significantly improved after the SE (p < 0.05) but did not change after the CE and NE (p > 0.05). Furthermore, in the SE condition, SEBT scores of the posterolateral and posteromedial directions were significantly improved at the posttest, compared with those at the pretest (p < 0.05).

CONCLUSIONS

This study demonstrated the immediate improvements in the posteromedial and posterolateral directions of the SEBT only after the SE. This result suggests that the SE used in this study is effective in immediately improving dynamic balance.

LEVELS OF EVIDENCE

3b.

Effects of two types of trunk exercises on balance and athletic performance in youth soccer players

PURPOSE/BACKGROUND

Many athletes perform trunk stabilization exercises (SE) and conventional trunk exercises (CE) to enhance trunk stability and strength. However, evidence regarding the specific training effects of SE and CE is lacking and there have been no studies for youth athletes. Therefore, the purpose of this study was to investigate the training effects of SE and CE on balance and athletic performance in youth soccer players.

METHODS

Twenty-seven male youth soccer players were assigned randomly to either an SE group (n = 13) or CE group (n = 14). Data from nineteen players who completed all training sessions were used for statistical analyses (SE, n = 10; CE, n = 9). Before and after the 12-week intervention program, pre- and post-testing comprised of a static balance test, Star Excursion Balance Test (SEBT), Cooper's test, sprint, the Step 50, vertical jump, and rebound jump were performed. After pre-testing, players performed the SE or CE program three times per week for 12 weeks. A two-way repeated-measures ANOVA was used to assess the changes over time, and differences between the groups. Within-group changes from pre-testing to post-testing were determined using paired t-tests. Statistical significance was inferred from p < 0.05.

RESULTS

There were significant group-by-time interactions for posterolateral (p = 0.022) and posteromedial (p < 0.001) directions of the SEBT. Paired t-tests revealed significant improvements of the posterolateral and posteromedial directions in the SE group. Although other measurements did not find group-by-time interactions, within-group changes were detected indicating significant improvements in the static balance test, Cooper's test, and rebound jump in the only SE group (p < 0.05). Vertical jump and sprint were improved significantly in both groups (p < 0.05), but the Step 50 was not improved in either group (p > 0.05).

CONCLUSIONS

Results suggested that the SE has specific training effects that enhance static and dynamic balance, Cooper's test, and rebound jump.

LEVEL OF EVIDENCE

3b.

Differences in EMG activity in scapular plane abduction under variable arm positions and loading conditions

PURPOSE

The present study was performed to investigate the activities of four shoulder muscles-the supraspinatus, the middle deltoid, the infraspinatus, and the upper trapezius-in scapular plane abduction in various exercise conditions.

METHODS

Eight male subjects (mean +/- SD: 23.4 +/- 1.3 yr) with an asymptomatic nondominant left shoulder participated in this study. Each subject performed scapular plane abduction with humeral external rotation (full can position) and with humeral internal rotation (empty can position), producing constant target torques of 4 and 12 N.m, respectively. In addition, the subjects performed each exercise in the supine position with the limb supported by straps. Electromyogram (EMG) was recorded with intramuscular electrodes at the supraspinatus and infraspinatus, and with surface electrodes placed at the middle deltoid and upper trapezius. The EMG activity (RMS) of each muscle was normalized according to the highest EMG activity (100% MVC) during a maximum manual muscle test for the corresponding muscle (% MVC).

RESULTS

EMG activity of the supraspinatus was significantly greater than those of the other shoulder muscles in the full can position from 10-20 degrees to 50-60 degrees arcs with a target torque of 4 N.m (P < 0.05). In contrast, the supraspinatus and middle deltoid showed similar EMG activities under other exercise conditions.

CONCLUSIONS

These results suggest that there is an exercise condition that induces greater activity of the supraspinatus in scapular plane abduction.

Epitope analysis of the cerebrospinal fluid IgG in HTLV-I associated myelopathy patients using phage display method

We, for the first time, analyzed the binding motifs of immunoglobulin G (IgG) in the cerebrospinal fluid (CSF) of human T lymphotropic virus type I (HTLV-I)-associated myelopathy/tropical spastic paraparesis (HAM/TSP) patients with a phage library displaying 12-mer random peptides. As a result, the sequences highly homologous to HTLV-I gp46 192-199, 237-243 and 255-261 were the common linear epitopes of high affinity- IgG exclusively detected in both CSF and sera of the patients. These IgG responses were confirmed with corresponding HTLV-I peptides and serum antibody titers significantly correlated with disease severity or duration. Gp46 237-243 has not been detected in previous enzyme-linked immunosorbent assay (ELISA) studies using bound longer peptides, suggesting the usefulness of the phage display method.

No strong relationship between mannan binding lectin or plasma ficolins and chemotherapy-related infections

Chemotherapy causes neutropenia and an increased susceptibility to infection. Recent reports indicate that mannan-binding lectin (MBL) insufficiency is associated with an increased duration of febrile neutropenia and incidence of serious infections following chemotherapy for haematological malignancies. We aimed to confirm or refute this finding and to extend the investigation to the plasma ficolins, P35 (L-ficolin) and the Hakata antigen (H-ficolin). MBL, L-ficolin and H-ficolin were measured in 128 patients with haematological malignancies treated by chemotherapy alone or combined with bone marrow transplantation. Protein concentrations were related to clinical data retrieved from medical records. MBL concentrations were elevated compared with healthy controls in patients who received chemotherapy, while L-ficolin concentrations were decreased and H-ficolin levels were unchanged. There was no correlation between MBL, L-ficolin or H-ficolin concentration and febrile neutropenia expressed as the proportion of neutropenic periods in which patients experienced fever, and there was no relation between abnormally low (deficiency) levels of MBL, L-ficolin or H-ficolin and febrile neutropenia so expressed. Patients with MBL < or =0.1 microg/ml had significantly more major infections than no infections within the follow-up period (P<0.05), but overall most patients had signs or symptoms of minor infections irrespective of MBL concentration. Neither L-ficolin nor H-ficolin deficiencies were associated with infections individually, in combination or in combination with MBL deficiency. MBL, L-ficolin and H-ficolin, independently or in combination, did not have a major influence on susceptibility to infection in these patients rendered neutropenic by chemotherapy. These results cast doubt on the potential value of MBL replacement therapy in this clinical context.

The effects of various therapeutic measures on shoulder range of motion and cross-sectional areas of rotator cuff muscles after baseball pitching

AIM

The purpose of this study was to investigate the effects of various therapeutic measures on the shoulder range of motion (ROM) and muscle cross-sectional area (mCSA) of rotator cuff muscles after baseball pitching.

METHODS

EXPERIMENTAL DESIGN

a mode of therapeutic measures was classified in 4 groups; the control (CON), ice treatment (IT), light shoulder exercise (LSE) and ice treatment with LSE (ILSE) groups. Each therapeutic measure was performed after pitching.

PARTICIPANTS

7 healthy, skilled baseball pitchers.

MEASURES

ROM and mCSA were measured before pitching, immediately after pitching, at the time of the therapeutic measure, and 24 hours after pitching. Shoulder ROM at 90 inverted exclamation mark of abduction included internal rotation (IROM), maximum internal rotation (IMROM), external rotation (EROM) and maximum external rotation (EMROM).

RESULTS

In all groups, both IROM and IMROM were significantly decreased after pitching compared with the pre-exercise values and conversely both EROM and EMROM were significantly increased. The mCSA of all rotator cuff muscles were increased significantly after pitching. For IMROM, ILSE showed a significant recovery at the post-therapeutic measure compared with the others and at 24 hours after pitching compared with IT, respectively. For IROM, both LSE and ILSE showed significant recovery compared with CON at the post-therapeutic measure. For the mCSA of external muscles, ILSE showed a greater decrease at the post-therapeutic measure than the others, and at 24 hours after pitching than CON.

CONCLUSION

This study suggested the possibility that ILSE was more effective to recover ROM and decrease mCSA than the other methods.

The effects of various therapeutic measures on shoulder strength and muscle soreness after baseball pitching

AIM

This study was intended as an investigation of the effects of various therapeutic measures on the shoulder strength and muscle soreness after baseball pitching.

METHODS

EXPERIMENTAL DESIGN

participants threw 98 pitches in a simulated single game. The mode of the therapeutic measures after pitching were classified into 4 groups; the control group (CON), the ice treatment group (IT), the light shoulder exercise group (LSE) and the ice treatment with LSE group (ILSE). Each therapeutic measure was applied to the dominant shoulder immediately after pitching.

PARTICIPANTS

7 healthy, skilled baseball pitchers.

MEASURES

both shoulder strength and muscle soreness were measured before pitching, immediately after pitching (Post-P), at the time of the therapeutic measure (Post-TM), and 24 hours after pitching (Post-24 h).

RESULTS

All 4 groups showed shoulder strength losses in shoulder abduction, internal/external rotation with no shoulder abduction or with the shoulder abducted to 90 degrees immediately after pitching. ILSE had greater recovery from Post-P values at Post-TM or Post-24 h than the other methods in all 5 shoulder strengths. On the other hand, the soreness in shoulder internal rotation was increased significantly from Post-P and continued by Post-24 h. Both IT and ILSE had beneficial effects on reducing the shoulder muscle soreness at Post-TM or Post-24 h.

CONCLUSION

The findings of this study suggested that ILSE was the optimal therapeutic measure against decreased shoulder strength or increased shoulder muscle soreness resulting from the repetitive baseball pitching.

Use of odorless thiols: formal asymmetric Michael addition of hydrogen sulfide to alpha-substituted alpha,beta-unsaturated carbonyl compounds

[reaction: see text] The Michael addition to alpha-substituted alpha,beta-unsaturated esters and amides using complex A containing a chiral odorless thiol proceeded diastereoselectively. The Michael adducts were converted to beta-mercapto esters and amides via a Wagner-Meerwein rearrangement with boron trifluoride etherate and a thiol exchange reaction using odorless 1-dodecanethiol. This conversion constitutes a formal asymmetric Michael addition of hydrogen sulfide to alpha,beta-unsaturated carbonyl compounds using odorless thiols instead of the toxic hydrogen sulfide.

Adrenergic nerves mediate acetylcholine-induced endothelium-independent vasodilation in the rat mesenteric resistance artery

Mechanisms underlying acetylcholine-induced endothelium-independent vasodilation were studied in the rat mesenteric vascular bed isolated from Wistar rats. In preparations without endothelium, and contracted by perfusion with Krebs solution containing methoxamine (2-7 microM), perfusion of acetylcholine (1-100 microM) for 1 min produced a concentration-dependent vasodilation. Denervation of denuded preparations by cold storage (4 degrees C for 72 h) abolished the acetylcholine-induced vasodilation; 10 and 100 nM atropine abolished 1 and 10 microM acetylcholine-induced vasodilation, but it inhibited only 20% of vasodilation by 100 microM acetylcholine. The acetylcholine-induced atropine-resistant vasodilation was inhibited by 10 and 100 microM hexamethonium, 5 microM guanethidine, 50 microM bretylium, in vitro 6-hydroxydopamine (2 mM for 20 min, twice), 1 microM capsaicin and 0.5 microM calcitonin gene-related peptide (CGRP)-(8-37) (CGRP receptor antagonist). These findings suggest that the acetylcholine-induced endothelium-independent nicotinic vasodilation requires the presence of intact adrenergic nerves, and is mediated by endogenous CGRP released from CGRP-containing nerves.

Detection of serum thermolabile beta-2 macroglycoprotein (Hakata antigen) by enzyme-linked immunosorbent assay using polysaccharide produced by Aerococcus viridans

Although a serum thermolabile beta-2 macroglycoprotein (TMG) may play a role in host defense as a lectin, little is known of its related physiological functions, mainly due to a lack of appropriate methods for tracing the functions of TMG. We identified a polysaccharide from Aerococcus viridans, PSA, which reacts with TMG, and based on this finding, we developed an enzyme-linked immunosorbent assay to trace the functions of TMG. Using ethanol precipitation and DEAE-Sepharose and Sephacryl S-400 column chromatographies, we isolated PSA from cultured medium of A. viridans, and it exhibited specific binding against TMG in blood samples. In sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE), the isolated PSA showed ladder bands that implied the existence of repeating units composed of D-glucose, N-acetyl-D-glucosamine, D-mannose, and D-xylose, as confirmed by gas chromatography-mass spectrometry. SDS-PAGE and immunochemical analysis, using rabbit anti-TMG antibody, showed that PSA specifically binds solely to intact serum TMG but not to TMG heated at 56 degrees C for 30 min, a condition under which antigenicity is lost. TMG in serum samples bound to PSA in a dose-dependent manner, and this binding was clearly suppressed by addition of PSA. These observations indicate that PSA is a useful adsorbent to TMG and can be used to develop appropriate methods for tracing the functions of TMG.

Phosphatidylglycerol participates in syncytium formation induced by HTLV type 1-bearing cells

We previously reported that 71-kDa heat shock cognate protein (HSC70) was expressed on the cell surface of human T cell lymphotropic virus type 1 (HTLV-1)-susceptible cells and that HSC70, beta-actin, and a lipid-like component on the target cell membrane participated in syncytium formation by HTLV-1. We have now identified this lipid-like component to be palmitoyl (16:0)-oleoyl (18:1)-phosphatidylglycerol (POPG), using preparative thin-layer chromatographic fractionation and tandem mass spectrometric analysis. In the syncytium formation assay, exogenously added PG inhibited cell-to-cell transmission of HTLV-1 in a dose-dependent manner. Other phospholipids showed less (PE) or no effect (PC, PS, PI, PA, lysoPC, lysoPE, and CL). Binding experiments showed that PG interacted with three synthetic peptides, gp46--111, gp46--197, and gp21--400, which correspond to regions Lys111--Asp138 and Asp197--Leu216 on the gp46 surface glycoprotein, and to region Cys400--Leu429 on the gp21 transmembrane glycoprotein, respectively, as well as with intact gp46 and gp21 proteins of HTLV-1. On the other hand, HSC70 and beta-actin interacted with gp46--197 and gp46, not with gp46--111. However, the eluate from an affinity column coupled with gp46--111 contained not only PG but also HSC70 and beta-actin, despite the lack of direct interaction between gp46--111 and these proteins. In the in vitro binding assay, HSC70 showed interaction with both PG and beta-actin, while there was no evidence of any interaction between PG and beta-actin. These results suggest that HSC70 molecules on target cell surface interact with both PG in lipid bilayers and intracellular beta-actin and that these three cellular components form a receptor complex that plays a critical role in syncytium formation induced by HTLV-1-bearing cells.

HTLV type 1 envelope glycoprotein gp46 evokes necrosis by binding to receptor complex

In syncytium formation induced by HTLV-1-bearing cells, 71-kDa heat shock cognate protein (HSC70) functions as a receptor molecule and the receptor complex with beta-actin and palmitoyl(16:0)-oleoyl(18:1)-phosphatidylglycerol (PG) is thus formed. We now have evidence that the molecular association between HTLV-1 gp46 envelope protein and HSC70 led to pore formation on the surface of target cell membrane and cell death followed. The peptide segment corresponding to the region from Asp-197 to Leu-216 (gp46-197), and which serves as a binding site to both HSC70 and PG for syncytium formation, also had cytotoxic effects on target cell MOLT-4. This cytotoxicity was due to necrosis, not apoptosis. On the other hand, two other receptor-binding sites, Lys-111 to Asp-138 on gp46 (gp46-111) and Cys-400 to Leu-429 on gp21 (gp21-400), and which bound only with PG, had no cytotoxic effects on MOLT-4 cells. The HTLV-2 peptide (gp46-194; Glu194 to Leu-213) corresponding to the region of HTLV-1 gp46-197 showed no cytotoxicity, and interacted only with PG, not with either HSC70 or beta-actin. Amino acid alterations between HTLV-1 gp46-197 and HTLV-2 gp46-194 were significant on the hydrophilic face of the amphipathic structure. Taken together, the interaction between HSC70 and gp46 of HTLV-1 through the hydrophilic face of gp46-197 may lead to pore formation in lipid bilayers to be followed by membrane fusion or cell death.

Endogenous calcitonin gene-related peptide (CGRP) mediates adrenergic-dependent vasodilation induced by nicotine in mesenteric resistance arteries of the rat

1. The mechanisms underlying vasodilator effect of nicotine on mesenteric resistance blood vessels and the role of calcitonin gene-related peptide (CGRP)-containing (CGRPergic) vasodilator nerves were studied in the rat. 2. Mesenteric vascular beds isolated from Wistar rats were perfused with Krebs solution, and perfusion pressure was measured with a pressure transducer. 3. In preparations with intact endothelium and contracted by perfusion with Krebs solution containing methoxamine, perfusion of nicotine (1 - 100 microM) for 1 min caused a concentration-dependent vasodilator response without vasoconstriction. 4. The nicotine-induced vasodilation was markedly inhibited by hexamethonium (nicotinic cholinoceptor antagonist, 10 microM) and blocked by guanethidine (adrenergic neuron blocker, 5 microM). 5. Either denervation by cold storage (4 degrees C for 72 h) or adrenergic denervation by 6-hydroxydopamine (toxin for adrenergic neurons, 2 mM for 20 min incubation, twice) blocked the nicotine-induced vasodilation. 6. Neither endothelium removal with perfusion of sodium deoxycholate (1.80 mg ml(-1), for 30 s) nor treatment with N(omega)-nitro-L-arginine (nitric oxide synthase inhibitor, 100 microM), atropine (muscarinic cholinoceptor antagonist, 10 nM) or propranolol (beta-adrenoceptor antagonist, 100 nM) affected the nicotine-induced vasodilation. 7. In preparations without endothelium, treatment with capsaicin (depleting CGRP-containing sensory nerves, 1 microM) or human CGRP[8 - 37] (CGRP receptor antagonist, 0.5 microM) markedly inhibited the nicotine-induced vasodilation. 8. These results suggest that, in the mesenteric resistanc artery of the rat, nicotine induces vasodilation, which is independent of the function of the endothelium and is involved in activation of CGRPergic nerves. It is also suggested that nicotine stimulates presynaptic nicotinic cholinoceptors on adrenergic nerves to release adrenergic neurotransmitters, which then act on CGRPergic nerves to release endogenous CGRP from the nerve.

Inhibition of cell-free human T-cell leukemia virus type 1 infection at a postbinding step by the synthetic peptide derived from an ectodomain of the gp21 transmembrane glycoprotein

To investigate the roles of human T-cell leukemia virus type 1 (HTLV-1) envelope (Env) proteins gp46 and gp21 in the early steps of infection, the effects of the 23 synthetic peptides covering the entire Env proteins on transmission of cell-free HTLV-1 were examined by PCR and by the plaque assay using a pseudotype of vesicular stomatis virus (VSV) bearing the Env of HTLV-1 [VSV(HTLV-1)]. The synthetic peptide corresponding to amino acids 400 to 429 of the gp21 Env protein (gp21 peptide 400-429, Cys-Arg-Phe-Pro-Asn-Ile-Thr-Asn-Ser-His-Val-Pro-Ile-Leu-Gln-Glu-Arg-P ro-Pro-Leu-Glu-Asn-Arg-Val-Leu-Thr-Gly-Trp-Gly-Leu) strongly inhibited infection of cell-free HTLV-1. By using the mutant peptide, Asn407, Ser408, and Leu413, -419, -424, and -429 were confirmed to be important amino acids for neutralizing activity of the gp21 peptide 400-429. Addition of this peptide before or during adsorption of HTLV-1 at 4 degrees C did not affect its entry. However, HTLV-1 infection was inhibited about 60% when the gp21 peptide 400-429 was added even 30 min after adsorption of HTLV-1 to cells, indicating that the amino acid sequence 400 to 429 on the gp21 Env protein plays an important role at the postbinding step of HTLV-1 infection. In contrast, a monoclonal antibody reported to recognize the gp46 191-196 peptide inhibited the infection of HTLV-1 at the binding step.

Detection of borna disease virus-reactive antibodies from patients with psychiatric disorders and from horses by electrochemiluminescence immunoassay

The prevalence of Borna disease virus (BDV)-specific antibodies among patients with psychiatric disorders and healthy individuals has varied in several reports using several different serological assay methods. A reliable and specific method for anti-BDV antibodies needs to be developed to clarify the pathological significance of BDV infections in humans. We developed a new electrochemiluminescence immunoassay (ECLIA) for the antibody to BDV that uses two recombinant proteins of BDV, p40 and p24 (full length). Using this ECLIA, we examined 3,476 serum samples from humans with various diseases and 917 sera from blood donors in Japan for the presence of anti-BDV antibodies. By ECLIA, 26 (3.08%) of 845 schizophrenia patients and 9 (3.59%) of 251 patients with mood disorders were seropositive for BDV. Among 323 patients with other psychiatric diseases, 114 with neurological diseases, 75 with chronic fatigue syndrome, 85 human immunodeficiency virus-infected patients, 50 with autoimmune diseases including rheumatoid arthritis and systemic lupus erythematosis and 17 with leprosy, there was no positive case except one case each with alcohol addiction, AIDS, and dementia. Although 19 (1.36%) of 1,393 patients with various ocular diseases, 10 (1.09%) of 917 blood donors, and 3 (4.55%) of 66 multitransfused patients were seropositive for BDV-specific antigen, high levels of seroprevalence in schizophrenia patients and young patients (16 to 59 years old) with mood disorders were statistically significant. The immunoreactivity of seropositive sera could be verified for specificity by blocking with soluble p40 and/or p24 recombinant protein. Anti-p24 antibody was more frequent than p40 antibody in most cases, and in some psychotic patients antibody profiles showed only p40 antibody. Although serum positive for both p40 and p24 antibodies was not found in this study, the p40 ECLIA count in schizophrenia patients was higher than that of blood donors. Furthermore, we examined 90 sera from Japanese feral horses. Antibody profiles of control human samples are similar to that of naturally BDV-infected feral horses. We concluded that BDV infection was associated in some way with psychiatric disorders.

Detection of bikunin mRNA in limited portions of rat brain

Tissue distribution of bikunin mRNA, which encodes a Kunitz-type serine protease inhibitor of the inter-alpha-inhibitor family (IalphaI), was studied in rats and mice by the reverse-transcripsion polymerase chain reaction (RT-PCR). We found that the liver as well as other tissues, such as the kidney, testis and adrenal gland, expressed bikunin mRNA. Although signals of bikunin mRNA were faint in the whole brain of rats and mice, distinct signals were found in limited portions of rat brain, such as the hippocampus, cerebral cortex and pituitary, but undetectable in cerebellum, medulla oblongata, hypothalamus, striatum, midbrain and choroid plexus. In three distinct types of cells, such as neurons, astrocytes and meningeal cells, in primary cultures isolated from the cerebral cortex and meninges of 1-day-old newborn rats, only neurons positively expressed bikunin mRNA. These results suggest that, in addition to peripheral tissues, neurons in the hippocampus and cerebral cortex produce bikunin, suggesting a potential role of bikunin/IalphaI family in these brain regions.

Human complement component C1q inhibits the infectivity of cell-free HTLV-I

Human T cell leukemia virus type I (HTLV-I) is a retrovirus that is not lysed by human serum or complement. It has not been determined, however, whether HTLV-I directly binds to complement components or whether it retains infectivity after incubation with human serum. We investigated the effects of human serum on the infectivity of cell-free HTLV-I produced by human and animal cells. Plating of vesicular stomatitis virus (HTLV-I) pseudotypes prepared in cat or human cells and formation of HTLV-I DNA after infection of cell-free HTLV-I produced by cat or human cells were markedly inhibited by treatment with fresh human serum, but not by heat-inactivated serum. HTLV-I infection was also inhibited by treatment with C2-, C3-, C6-, or C9-deficient serum, but not by C1q-deficient serum. Inhibitory activities of normal human serum against HTLV-I were neutralized by anti-C1q serum. Furthermore, purified C1q inhibited HTLV-I infection. The direct binding of C1q to HTLV-I was confirmed by comigration of C1q with HTLV-I virion upon sucrose density gradient ultracentrifugation of HTLV-I virion treated with C1q. Binding assay using synthetic envelope peptides indicated that C1q bound to an extramembrane region of the gp21 transmembrane protein. These findings indicate that the human complement component C1q inactivates HTLV-I infectivity.

Association between preinfarction angina and a lower risk of right ventricular infarction

BACKGROUND

Right ventricular infarction occurs in conjunction with inferior myocardial infarction caused by proximal occlusion of the right coronary artery. However, right ventricular infarction occurs infrequently, and the reasons for this are uncertain.

METHODS

We retrospectively assessed the association between preinfarction angina and right ventricular infarction, as well as the short-term outcome, in 113 patients with a first acute inferior myocardial infarction caused by right-coronary-artery occlusion. The association between the timing of angina during the week before infarction and the clinical outcome was also assessed.

RESULTS

The absence of preinfarction angina predicted the development of right ventricular infarction (odds ratio, 6.3; 95 percent confidence interval, 2.7 to 15.1; P<0.001), complete atrioventricular block (odds ratio, 3.6; 95 percent confidence interval, 1.4 to 10.3; P=0.01), and combined hypotension and shock (odds ratio, 12.4; 95 percent confidence interval, 4.5 to 40.6; P<0.001). Angina 24 to 72 hours before infarction was most strongly associated with reductions in the rates of right ventricular infarction (adjusted odds ratio, 0.2; 95 percent confidence interval, 0 to 0.8; P=0.02) and combined hypotension and shock (adjusted odds ratio, 0.1; 95 percent confidence interval, 0 to 0.5; P=0.02).

CONCLUSIONS

Preinfarction angina was an independent predictor of the absence of right ventricular infarction in patients with acute inferior myocardial infarction. The patients with preinfarction angina also had better short-term outcomes than those without preinfarction angina.

71-kilodalton heat shock cognate protein acts as a cellular receptor for syncytium formation induced by human T-cell lymphotropic virus type 1

We previously reported that the region corresponding to amino acids 197 to 216 of the gp46 surface glycoprotein (gp46-197) served as a binding domain for the interaction between gp46 and trypsin-sensitive membrane components of the target cell, leading to syncytium formation induced by human T-cell lymphotropic virus type 1 (HTLV-1)-bearing cells. Our new evidence shows that the 71-kDa heat shock cognate protein (HSC70) acts as a cellular receptor for syncytium formation. Using affinity chromatography with the peptide gp46-197, followed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis, we isolated three components (bands A, B, and C) from MOLT-4 cell lysate which exhibited specific interactions with gp46 and inhibitory activities for syncytium formation induced by HTLV-1-bearing cells. Band A and B components were identified as HSC70 and beta-actin, respectively, through amino acid sequencing by tandem mass spectrometry and immunostaining with specific monoclonal antibodies. Band C is likely to be a nonprotein component, because full activity for syncytium formation was seen after extensive trypsin digestion. Anti-HSC70 monoclonal antibody clearly blocked syncytium formation in a coculture of HTLV-1-bearing cells and indicator cells, whereas no inhibition was seen with anti-beta-actin monoclonal antibody. Furthermore, flow cytometric analysis indicated that anti-HSC70 antibody reacted with MOLT-4 cells. Thus, we propose that HSC70 expressed on the target cell surface acts as a cellular acceptor to gp46 exposed on the HTLV-1-infected cell for syncytium formation, thereby leading to cell-to-cell transmission of HTLV-1.

C-reactive protein as a predictor of infarct expansion and cardiac rupture after a first Q-wave acute myocardial infarction

BACKGROUND

Pump failure after acute myocardial infarction (AMI) can be predicted by several indices that estimate infarct size. However, there are few indices that predict infarct expansion and cardiac rupture. We focused on the prognostic significance of serum C-reactive protein (CRP) after AMI.

METHODS AND RESULTS

Serum CRP levels were measured every 24 hours in 220 patients with a first Q-wave AMI. In-hospital complications, predischarge left ventriculographic findings, and long-term prognosis were assessed in relation to peak CRP levels. Peak levels of both CRP and creatine kinase (CK) were higher in patients with pump failure than in those without pump failure. In patients with cardiac rupture, peak CRP levels were higher than in those without rupture (P=.001); peak CK levels were not predictive. Higher CRP levels were found in patients with left ventricular aneurysm (P=.001 versus those without), aggravated heart failure (P=.03 versus those without), and cardiac death (P<.0001 versus survivors) during the first year after AMI. Multivariate analysis confirmed that an elevation of the peak CRP level > or = 20 mg/dL was an independent predictor of cardiac rupture (relative risk, 4.72; P=.004), left ventricular aneurysmal formation (relative risk, 2.11; P=.03), and 1-year cardiac death (relative risk, 3.44; P<.0001).

CONCLUSIONS

Cardiac rupture, left ventricular aneurysmal formation, and 1-year cardiac death were associated with an elevation of serum CRP early after AMI, suggesting that elevation of CRP levels after AMI may predict infarct expansion.

Clonal integration and expression of human T-cell lymphotropic virus type I in carriers detected by polymerase chain reaction and inverse PCR

Adult T-cell leukemia (ATL) is a neoplasm of mature helper (CD4) T lymphocytes, and human T-cell lymphotropic virus type-I (HTLV-I) has been suggested to be the causative virus of ATL. HTLV-I integrates its proviruses into random sites in host chromosomal DNA. Clonal integration has been observed in patients with ATL, including smoldering, chronic, and acute states. However, random and/or polyclonal integration has only been reported in a few asymptomatic HTLV-I carriers. To clarify the clonality of HTLV-I-infected cells in carriers, we used an inverse polymerase chain reaction (IPCR), which is more sensitive than Southern blot analysis. We used the peripheral blood momonuclear cells (PBMC) from 16 asymptomatic carriers and the separated CD4-positive cells. No cases showed either a monoclonal or polyclonal integration of the HTLV-I provirus by Southern blot. But, using IPCR, 7 of 16 cases showed either mono- or oligoclonal integration. In addition, the populations of clonal provirus in the total PBMC were frequently different from those in the CD4-positive cells. Three cases showed expression of HTLV-I tax/rex mRNA in the total PBMC, but no such expression was found in CD4-positive cells. In this study, an unexpected frequency of clonal HTLV-I provirus DNA was observed in HTLV-I carriers. These findings indicate that the clonal but nonmalignant proliferation of HTLV-I-infected cells already occurs even in HTLV-I carriers, and therefore that some other step is necessary to induce malignant proliferation.

Trypsin-sensitive and -resistant components in human T-cell membranes required for syncytium formation by human T-cell lymphotropic virus type 1-bearing cells

Human T-cell lymphotropic virus type 1 (HTLV-1) envelope proteins play an important role in viral entry into target cells. In a syncytium formation assay consisting of a coculture of HTLV-1-bearing cells and target cells, mature gp46 and gp21 proteins each inhibited syncytium formation induced by HTLV-1-bearing cells. Experiments with 125I-labeled proteins showed that 125I-gp46 bound specifically with MOLT-4 target cells even in the presence of large amounts of gp21, whereas 125I-gp21 binding to target cells was completely blocked in the presence of large amounts of gp46. These observations suggest that HTLV-1 envelope proteins in syncytium formation interact with at least two components, which are located close to each other on the cell membrane. We isolated two components from MOLT-4 cell lysate, using Sepharose 4B columns coupled with peptides corresponding to amino acids 197 to 216 and 400 to 429, respectively, of the envelope protein. One is a trypsin digestion-sensitive component of approximately 34 to 35 kDa, which interacts specifically with gp46. The other is a nonprotein component, which interacts with gp21. This component was destroyed by sodium periodate oxidation and was partitioned into the methanol-chloroform phase. These observations suggest that these two components play an important role in HTLV-1 entry into target cells via membrane fusion.

Myocardial sympathetic denervation prevents chamber-specific alteration of beta-adrenergic transmembrane signaling in rabbits with heart failure

OBJECTIVES

The purpose of this study was to assess the effect of myocardial sympathetic denervation on the chamber-specific alteration of beta-adrenergic signaling in left ventricular failure in rabbits.

BACKGROUND

Local abnormalities in sympathetic nerve terminals, including the neuronal reuptake of norepinephrine, are thought to be responsible for the chamber-specific regulation of beta-adrenergic signaling in heart failure.

METHODS

Sixteen rabbits were given 6-hydroxydopamine, 25 mg/kg body weight intravenously on days 1 and 2 and 50 mg/kg intravenously on days 7 and 8. Another 16 rabbits received vehicle. Aortic regurgitation was induced in eight of the 6-hydroxydopamine-treated and eight of the vehicle-treated rabbits on day 14. Another eight of the 6-hydroxydopamine-treated and eight of the vehicle-treated rabbits underwent a sham operation. The hearts were excised for biochemical analysis on day 21.

RESULTS

Hemodynamic characteristics on day 21 showed left ventricular failure in both the aortic regurgitation groups. The plasma norepinephrine concentration on day 21 was higher in both the aortic regurgitation groups than in the sham groups. The beta-adrenoceptor densities and isoproterenol plus 5'-guanylylimidodiphosphate-, 5'-guanylylimidodiphosphate- and sodium fluoride-stimulated adenylyl cyclase activities were decreased only in the failing left ventricle of the vehicle-pretreated aortic regurgitation group, but in both ventricles of the 6-hydroxydopamine-pretreated aortic regurgitation group. The basal and forskolin-stimulated adenylyl cyclase activities were similar in both the aortic regurgitation groups and in the sham groups.

CONCLUSIONS

Sympathetic denervation prevented chamber-specific alterations in beta-adrenergic signaling in acute left ventricular failure. Local loss of sympathetic nerve endings, and especially the defective neuronal norepinephrine reuptake, are likely to be responsible for the chamber-specific alteration of the beta-adrenoceptor-G protein-adenylyl cyclase system in heart failure in rabbits.