Diagnostic ability of Japanese version of high bleeding risk criteria for ischemic outcomes in patients with acute myocardial infarction.

The Japanese version of high bleeding risk (J-HBR) criteria was domestically proposed to identify patients at HBR after percutaneous coronary intervention (PCI). The applicability of J-HBR on bleeding events has been validated, while whether J-HBR predicts ischemic events is uncertain. This bi-center registry included 904 patients with acute myocardial infarction (MI) undergoing primary PCI. Patients were stratified by the J-HBR major (1 point) and minor (0.5 point) criteria. Patients with J-HBR ≥ 1 point were diagnosed as having HBR. The primary endpoint was major adverse cardiovascular events (MACE), a composite of cardiovascular death, recurrent MI, and ischemic stroke, after discharge. Of the 904 patients, 451 (49.9%) had the J-HBR. The primary endpoint more frequently occurred in patients with J-HBR than in those without (10.9% vs. 4.9%, p < 0.001) during the median follow-up period of 522 days. Probability of MACE was progressively increased with the increase in the number of J-HBR major and minor criteria, in which severe anemia, severe chronic kidney disease, prior heart failure, peripheral artery disease, and prior ischemic stroke were identified as significant factors associated with MACE. In patients with acute MI undergoing PCI, the J-HBR criteria were predictive for ischemic outcomes after discharge, suggesting that the J-HBR criteria may be useful to identify patients at high bleeding and ischemic risks.

Biceps femoris long head stiffens after 2 weeks of training cessation in highly trained sprinters.

PURPOSE: Most athletes experience short-term training cessation because of illness, injury, post-season vacation, or other reasons. Passive muscle stiffness is a potential risk factor for a sprint-type hamstring strain injury, but limited information is available about the effect of short-term training cessation on passive muscle stiffness. The present study aimed to identify whether and how passive muscle stiffness of the biceps femoris long head (BFlh) would vary due to 2 weeks of training cessation in sprinters. METHODS: Passive BFlh shear-wave speed (a proxy for stiffness) was measured using ultrasound shear-wave elastography in 28 male sprinters, before and after 2 weeks of intervention. During the 2 weeks, the participants in the training-cessation group (n = 14) were allowed to maintain their normal daily activities but not to perform any physical training, including stretching and resistance exercises. The participants in the training continuation group (n = 14) performed the training (including maximum speed sprint, plyometric, and weight training) prescribed by their coaches 5 days per week. RESULTS: In the training-cessation group, passive BFlh shear-wave speed increased after the 2 weeks of training cessation (4.75 ± 0.77 to 5.00 ± 0.88 m/s, P < 0.001). In contrast, there was no significant difference before and after the 2 weeks of training continuation (4.90 ± 0.85 to 4.93 ± 0.85 m/s, P = 0.521). CONCLUSIONS: The present findings indicate that muscles stiffen by training cessation in sprinting athletes.

Prognostic Value of Natriuretic Peptide Levels and In-Hospital Heart Failure Events in Patients With Acute Myocardial Infarction.

BACKGROUND: In patients with acute myocardial infarction (AMI), elevated natriuretic peptide (NP) concentrations are reportedly associated with worse clinical outcomes. This study evaluated the prognostic value of NP concentrations and in-hospital heart failure (HF) events after AMI.Methods and Results: The present bicenter registry included 600 patients with AMI undergoing percutaneous coronary intervention. HF was evaluated at 3 different time points after AMI: on admission, during hospitalization, and at the short-term follow-up at 1 month. When HF was present at each time point, 1 point was assigned to the "HF time points" (HFTP) risk scoring system; possible total scores on this system ranged from 0 to 3. The primary endpoint was a composite of all-cause death and HF rehospitalization after discharge. Among the 600 patients who survived to discharge, the primary outcome occurred in 69 (11.5%) during a mean follow-up period of 488 days. HF on admission, during hospitalization, and at the short-term follow-up were all significantly associated with subsequent clinical outcomes. Higher scores on the HFTP scoring system were related to an increased risk of the primary endpoint. Multivariable analysis indicated scores of 2 and 3 were independently associated with outcome events in a stepwise manner. CONCLUSIONS: Among patients with AMI, HF evaluation at different time points was useful in stratifying risks of mortality and HF rehospitalization after discharge.

Validation of pressure-bounded coronary flow reserve using invasive coronary physiologic assessment.

Coronary flow reserve (CFR) represents entire coronary compensatory capacity. While CFR assessment is recommended to identify patients at an increased risk of cardiovascular events and coronary microvascular dysfunction, invasive CFR measurement is often technically challenging. Although not well validated yet, pressure-bounded CFR (pbCFR) has been proposed as a simple surrogate to estimate impaired CFR. In this study, we evaluated coronary physiological characteristics of low pbCFR using detailed invasive assessment. Invasive physiological assessment including resting ratio of distal coronary pressure to aortic pressure (Pd/Pa), fractional flow reserve (FFR), resting and hyperemic mean transit time, index of microcirculatory resistance (IMR), CFR, resistive reserve ratio, and microvascular resistance reserve (MRR) was performed in 107 patients in the left anterior descending coronary artery. pbCFR was calculated only with resting Pd/Pa and FFR. Patients were divided into low pbCFR and non-low pbCFR groups. Of 107 patients, 50 (46.7%) had low pbCFR. FFR (0.90 ± 0.05 vs. 0.83 ± 0.05, p < 0.001), hyperemic mean transit time (0.27 ± 0.17 vs. 0.21 ± 0.12, p = 0.04), and IMR (20.4 ± 13.2 vs. 15.0 ± 9.1, p = 0.01) were significantly higher in the low pbCFR group than their counterpart. While directly measured CFR did not differ significantly (4.4 ± 2.3 vs. 5.1 ± 2.8, p = 0.18), MRR was lower in the low pbCFR group (5.4 ± 3.0 vs. 6.8 ± 3.8, p = 0.047). The rates of CFR < 2.0 and IMR ≥ 25 were not significantly different between the 2 groups. In conclusion, although CFR did not differ significantly, IMR and MRR were impaired in patients with low pbCFR, suggesting pbCFR as a potential surrogate of coronary microvascular function in clinical practice.

Neuromuscular characteristics of front and back legs in junior fencers.

In elite fencers, muscle strength and muscle mass of the front leg (FL) are greater than those of the back leg (BL) due to characteristic physiological and biomechanical demands placed on each leg during fencing. However, the development of laterality in their neural and muscular components is not well-understood. The present study investigated neuromuscular characteristics of FL and BL in junior fencers. Nineteen junior fencers performed neuromuscular performance tests for FL and BL, separately. There were no significant differences in the isometric knee extension strength (MVC), unilateral vertical jump (UVJ), vastus lateralis muscle thickness (MT), or motor unit firing rate of the vastus lateralis muscle (MUFR) between FL and BL (p > 0.05). In subgroup analyses, a significantly greater MUFR in FL than BL was noted only in fencers with > 3 years of fencing experience, and significantly greater UVJ in FL than BL was observed solely in fencers with < 3 years of fencing experience (p < 0.05). Strong positive correlations between FL and BL were identified in MVC, MT, and MUFR in fencers with > 3 years of fencing experience, but not in those with < 3 years of experience. These findings suggest that in junior fencers, laterality in neuromuscular performance has not manifested, whereas longer fencing experience induces fencing-dependent laterality in neural components, and laterality in dynamic muscle strength is decreased with fencing experience.

Clinical Outcomes of Urgent or Emergency Transcatheter Aortic Valve Implantation　- Insights From the Nationwide Registry of Japan Transcatheter Valve Therapies.

BACKGROUND: Limited data are available for clinical outcomes in patients who underwent urgent or emergency transcatheter aortic valve implantation (TAVI). This study investigated in-hospital and 1-year outcomes and explored prognostic covariates in urgent/emergency TAVI using nationwide registry data.Methods and Results: Among 26,775 patients who underwent TAVI between August 2013 and December 2019, 25,495 with 1-year follow-up information were analyzed in this study. Baseline and procedural characteristics, as well as clinical adverse events, were compared between the urgent/emergency and elective TAVI groups. The primary outcome was all-cause mortality within 1 year after TAVI. Multivariable Cox regression models were constructed to identify independent predictors after urgent or emergency TAVI. Urgent or emergency TAVI was performed in 578 (2.3%) patients. The Society of Thoracic Surgeons score was significantly higher in the urgent/emergency than elective TAVI group (13.3% vs. 6.0%; P<0.001). Device success rate was comparable between the 2 groups. All-cause death-free survival within 1 year was lower in the urgent/emergency than elective TAVI group (77.2% vs. 92.2%; log rank P<0.001). Malignancy, albumin and creatinine concentrations, ejection fraction, and mean pressure gradient were associated with 1-year mortality in the urgent/emergency TAVI group. CONCLUSIONS: Despite higher surgical risk and more comorbidities, the procedure was successfully performed in patients undergoing urgent/emergency TAVI, although it should be noted that prognosis was worse than for elective TAVI.

Impact of PARIS and CREDO-Kyoto Thrombotic and Bleeding Risk Scores on Clinical Outcomes in Patients With Acute Myocardial Infarction.

BACKGROUND: The PARIS and CREDO-Kyoto risk scores were developed to identify patients at risks of thrombotic and bleeding events individually after percutaneous coronary intervention (PCI). However, these scores have not been well validated in different cohorts.Methods and Results:This 2-center registry enrolled 905 patients with acute myocardial infarction (MI) undergoing primary PCI. Patients were divided into 3 groups according to the PARIS and CREDO-Kyoto thrombotic and bleeding risk scores. The study endpoints included ischemic (cardiovascular death, recurrent MI, and ischemic stroke) and major bleeding events. Of 905 patients, 230 (25%) and 219 (24%) had high thrombotic and bleeding risks, respectively, with the PARIS scores, compared with 78 (9%) and 50 (6%) patients, respectively, with the CREDO-Kyoto scores. According to the 2 scores, >50% of patients with high bleeding risk had concomitant high thrombotic risk. During the mean follow-up period of 714 days, 163 (18.0%) and 95 (10.5%) patients experienced ischemic and bleeding events, respectively. Both PARIS and CREDO-Kyoto scores were significantly associated with ischemic and bleeding events after primary PCI. For ischemic events, the CREDO-Kyoto rather than PARIS thrombotic risk score had better diagnostic ability. CONCLUSIONS: In the present Japanese cohort of acute MI patients undergoing contemporary primary PCI, the PARIS and CREDO-Kyoto thrombotic and bleeding risk scores were discriminative for predicting ischemic and bleeding events.

Clinical Characteristics and Prognosis of Patients With No Standard Modifiable Risk Factors in Acute Myocardial Infarction.

BACKGROUND: Recently, the impact of the lack of standard modifiable risk factors, including hypertension, diabetes, dyslipidaemia, and current smoking, has been investigated in ST-segment elevation myocardial infarction (MI). The present study aimed to evaluate clinical characteristics and prognosis of the patients with no standard risk factors in acute MI. METHODS: This bi-centre registry included 1,093 patients with acute MI undergoing percutaneous coronary intervention. The participants were divided into two groups: patients having at least one of the four standard risk factors and those having none of the risk factors. The study endpoints included major adverse cardiovascular events (MACE) (death, recurrent MI, and stroke) and major bleeding events during hospitalisation. Any MACE and major bleeding events after discharge were also evaluated as an exploratory analysis. RESULTS: Of 1,093 patients, 64 (5.9%) had none of the four standard risk factors. The patients with no standard risk factors were likely to present with Killip class IV and cardiac arrest. The rate of in-hospital MACE was higher in patients with no risk factors than in their counterparts (25.0% vs 9.9%; p<0.001), whereas the incidence of in-hospital major bleeding was not significantly different between the two groups (9.4% vs 6.7%; p=0.44). Active cancer and autoimmune/inflammatory diseases were often found in patients with no standard risk factors. After discharge, no significant differences were observed in the risks of MACE and major bleeding events between the two groups. CONCLUSIONS: No standard modifiable risk factors were not uncommon and were associated with poor short-term outcomes in patients with acute MI.

Heterologous production of active form of beta-lytic protease by Bacillus subtilis and improvement of staphylolytic activity by protein engineering.

BACKGROUND: Most of the proteases classified into the M23 family in the MEROPS database exhibit staphylolytic activity and have potential as antibacterial agents. The M23 family is further classified into two subfamilies, M23A and M23B. Proteases of the M23A subfamily are thought to lack the capacity for self-maturation by auto-processing of a propeptide, which has been a challenge in heterologous production and application research. In this study, we investigated the heterologous expression, in Bacillus subtilis, of the Lysobacter enzymogenes beta-lytic protease (BLP), a member of the M23A subfamily. RESULTS: We found that B. subtilis can produce BLP in its active form. Two points were shown to be important for the production of BLP in B. subtilis. The first was that the extracellular proteases produced by the B. subtilis host are essential for BLP maturation. When the host strain was deficient in nine extracellular proteases, pro-BLP accumulated in the supernatant. This observation suggested that BLP lacks the capacity for self-maturation and that some protease from B. subtilis contributes to the cleavage of the propeptide of BLP. The second point was that the thiol-disulfide oxidoreductases BdbDC of the B. subtilis host are required for efficient secretory production of BLP. We infer that intramolecular disulfide bonds play an important role in the formation of the correct BLP conformation during secretion. We also achieved efficient protein engineering of BLP by utilizing the secretory expression system in B. subtilis. Saturation mutagenesis of Gln116 resulted in a Q116H mutant with enhanced staphylolytic activity. The minimum bactericidal concentration (MBC) of the wild-type BLP and the Q116H mutant against Staphylococcus aureus NCTC8325 was 0.75 µg/mL and 0.375 µg/mL, respectively, and the MBC against Staphylococcus aureus ATCC43300 was 6 µg/mL and 3 µg/mL, respectively. CONCLUSIONS: In this study, we succeeded in the secretory production of BLP in B. subtilis. To our knowledge, this work is the first report of the successful heterologous production of BLP in its active form, which opens up the possibility of industrial use of BLP. In addition, this study proposes a new strategy of using the extracellular proteases of B. subtilis for the maturation of heterologous proteins.

The Effect of Augmented Feedback Type and Frequency on Velocity-Based Training-Induced Adaptation and Retention.

Nagata, A, Doma, K, Yamashita, D, Hasegawa, H, and Mori, S. The effect of augmented feedback type and frequency on velocity-based training-induced adaptation and retention. J Strength Cond Res 34(11): 3110-3117, 2020-The purpose of this study was to compare the benefits of 4 weeks of velocity-based training (VBT) using different augmented feedback (AugFb) types and the frequency of AugFb, and whether adaptations are retained 10 days post-training. Thirty-seven collegiate male rugby players were divided into groups that received immediate feedback (ImFb; n = 9), visual feedback (ViFb; n = 10), average feedback (AvgFb; n = 10) and no feedback (NoFb; n = 8) during each VBT session consisting of 3 sets of 5 repetitions of loaded jump squats. The ImFb group received AugFb regarding lifting velocity under loaded jump squats (LV-JS) after every jump, whereas LV-JS measures were averaged after each set of jumps and presented to the AvgFb group. The LV-JS were video-recorded and displayed as kinematic feedback for the ViFb group after each set, although NoFb was provided for the NoFb group. Loaded jump squats measures were reported at baseline, during each training session and 10 days post-training. Loaded jump squats measures were significantly greater for the ImFb Group compared with the other groups during a number of post-baseline time points (p ≤ 0.05). Furthermore, at 4 weeks of VBT and 10 days post-retention, effect size (ES) calculations showed that LV-JS measures were greater with moderate to large effects for the ImFb group compared with the NoFb (ES = 1.02-1.25), AvgFb (ES = 0.78-0.82) and ViFb (ES = 0.74-1.60), respectively. However, LV-JS measures were reduced with moderate to large effects 10 days post-retention for the ViFb (ES = -0.60) and NoFb (ES = -0.85) groups. Providing LV-JS feedback after each jump appears to optimize performance and should be considered as a training tool during VBT.

Physical Characteristics and Performance of Japanese Top-Level American Football Players.

Yamashita, D, Asakura, M, Ito, Y, Yamada, S, and Yamada, Y. Physical characteristics and performance of Japanese top-level American football players. J Strength Cond Res 31(9): 2455-2461, 2017-This study aimed to compare the physical characteristics and performance between top-level nonprofessional football players in Japan and National Football League (NFL) Combine invited players and between top-level and middle-level players in Japan to determine the factors that enhance performance in international and national competitions. A total of 168 American football players (>20 years) in Japan participated in an anthropometric (height and weight) and physical (vertical jump, long jump, 40-yard dash, pro-agility shuttle, 3-cone drill, and bench press repetition test) measurement program based on the NFL Combine program to compete in the selection of candidates for the Senior World Championship. All players were categorized into 1 of the 3 position groups based on playing position: skill players, big skill players, and linemen. Japanese players were additionally categorized into selected and nonselected players for the second tryout. The NFL Combine candidates had significantly better performance than selected Japanese players on all variables except on performance related to quickness among the 3 position groups. Compared with nonselected players, selected Japanese skill players had better performance in the 40-yard dash and bench press test and big skill players had better performance in the vertical jump, broad jump, and 40-yard dash. Selected and nonselected Japanese linemen were not different in any measurements. These results showed the challenges in American football in Japan, which include not only improving physical performance of top-level players, but also increasing the number of football players with good physical performance.

Strategies for defending a dribbler: categorisation of three defensive patterns in 1-on-1 basketball.

To clarify the defending-dribbler mechanism, the interaction between the dribbler and defender should be investigated. The purposes of this study were to identify variables that explain the outcome (i.e. 'penetrating' and 'guarding') and to understand how defenders stop dribblers by categorising defensive patterns. Ten basketball players participated as 24 dribbler-defender pairs, who played a real-time, 1-on-1 sub-phase of the basketball. The trials were categorised into penetrating trials, where a dribbler invaded the defended area behind the defender, and guarding trials, where the defender stopped the dribbler's advance. Our results demonstrated that defenders in guarding trials initiated their movements earlier and moved quicker than the defenders in penetrating trials. Moreover, linear discriminant analysis revealed that the differences in initiation time and medio-lateral peak velocity between the defenders and dribblers were critical parameters for explaining the difference between penetrating and guarding trials. Lastly, guarding trials were further categorised into three process patterns during 1-on-1 basketball (i.e. 'early initiation' trials, 'quick movement' trials, and 'dribbler's stop' trials). The results suggest that there are three defending strategies and that one strategy would be insufficient to explain the defending-dribbler mechanism, because both players' anticipation and reactive movement must be considered.

Relation of Thrombolysis in Myocardial Infarction Frame Count to Invasively Measured Coronary Physiologic Indexes.

In the international guidelines, higher thrombolysis in myocardial infarction frame count (TFC) is indicated as evidence of coronary microvascular dysfunction (CMD). However, the association of TFC with invasively measured coronary physiologic parameters such as coronary flow reserve (CFR) and index of microcirculatory resistance (IMR) remains unclear. Patients without significant epicardial coronary lesions underwent invasive coronary physiologic assessment using a thermodilution method in the left anterior descending artery. Corrected TFC (cTFC) was evaluated on coronary angiography. The cut-off values of CFR and IMR were defined as ≤2.0 and >25, and patients with abnormal CFR and/or IMR were defined as having CMD. This study aimed to assess whether cTFC >25, a cut-off value in the guidelines, was diagnostic of the presence of CMD. Of the 137 patients, 34 (24.8%) and 32 (23.3%) had cTFC >25 and CMD, respectively. The rate of CMD was not significantly different between patients with and without cTFC >25. cTFC was weakly correlated with at rest and hyperemic mean transit time and IMR, whereas no significant correlation was observed between cTFC and CFR. The receiver operating characteristic curve analysis showed the poor diagnostic ability of cTFC for abnormal CFR and IMR and the presence of CMD. In conclusion, in patients without epicardial coronary lesions, cTFC as a continuous value and with the cut-off value of 25 was not diagnostic of abnormal CFR and IMR and the presence of CMD. Our results did not support the use of cTFC in CMD evaluation.

Relationship between jump height and lower limb joint kinetics and kinematics during countermovement jump in elite male athletes.

This study aims to identify the relationship between jump height and the kinetic and kinematic parameters of the hip, knee, and ankle joints during countermovement jump (CMJ) in elite male athletes. Sixty-six elite male athletes from various sports (strength and power, winter downhill, combat, ball game, and aquatic) performed maximal effort CMJs with hands and arms crossed against their chests on force platforms. Jumping motion in the sagittal plane was recorded using video analysis and the peak torque, power, and angular velocity of the right hip, knee, and ankle joints were calculated during the propulsive phase. Correlations between the CMJ height and kinetic and kinematic parameters were investigated using Pearson's product-moment coefficient (r) and Spearman's rank correlation coefficient (ρ). CMJ height was highly correlated with peak hip power (ρ = 0.686, p < 0.001) and peak knee angular velocity (r = 0.517, p < 0.001), and moderately correlated with peak hip angular velocity (r = 0.438, p < 0.001) and peak hip torque (r = 0.398, p = 0.001). These results indicate that notable hip torque and power can contribute to increased angular velocity in both the knee and hip joints, ultimately increasing the CMJ height in elite male athletes.

The Combinations of the Patterns of Non-adherence to Anti-platelet Regimen in Stented Patients (PARIS) and Coronary Revascularization Demonstrating Outcome Study in Kyoto (CREDO-Kyoto) Thrombotic and Bleeding Risk Scores on Clinical Outcomes in Patients with Acute Myocardial Infarction.

Objective The Patterns of Non-adherence to Anti-platelet Regimen in Stented Patients (PARIS) and Coronary Revascularization Demonstrating Outcome Study in Kyoto (CREDO-Kyoto) thrombotic and bleeding risk scores were established to predict ischemic and bleeding events in patients undergoing percutaneous coronary intervention (PCI). However, whether or not the combination of these risk scores is predictive of clinical outcomes is unclear. Methods This bicenter registry included a total of 1,098 patients with acute myocardial infarction (MI) undergoing primary PCI. Patients were divided into three groups according to the PARIS and CREDO-Kyoto thrombotic and bleeding risk scores. The study endpoints included the rates of both ischemic (cardiovascular death, recurrent MI, and ischemic stroke) and major bleeding (Bleeding Academic Research Consortium type 3 or 5) events at two years. Results Two years after primary PCI, ischemic and major bleeding events occurred in 17.3% and 10.2% of patients, respectively. The higher-risk categories of PARIS and CREDO-Kyoto scores were associated with increased risks of ischemic and bleeding events. The rates of ischemic and major bleeding events progressively increased with the increase in risk categories in the two risk scoring systems. In the receiver operating characteristic curve analysis, the addition of CREDO-Kyoto thrombotic and bleeding risk scores to PARIS scores significantly improved diagnostic ability in predicting ischemic (area under the curve: 0.59 vs. 0.63, p=0.01) and bleeding (area under the curve: 0.65 vs. 0.68, p=0.01) events. Conclusion The combinations of the PARIS and CREDO-Kyoto risk scores might be useful for evaluating ischemic and bleeding risks in patients with acute MI undergoing primary PCI.

Relationship between body mass index and clinical events in patients with atrial fibrillation undergoing percutaneous coronary intervention.

BACKGROUND: It is still unclear whether body mass index (BMI) affects bleeding and cardiovascular events in patients requiring oral anticoagulants (OAC) for atrial fibrillation (AF) and antiplatelet agents after percutaneous coronary intervention (PCI) for coronary artery disease (CAD). The aim of this study was to evaluate the relationship between BMI and clinical events in patients who underwent PCI under OAC therapy for AF. METHOD: This was a multicenter, observational cohort study conducted at 15 institutions in Japan. AF patients who underwent PCI with drug-eluting stents for CAD were retrospectively and prospectively included. Patients were divided into the Group 1 (BMI <21.3 kg/m2) and the Group 2 (BMI ≥21.3 kg/m2) according to the first-quartile value of BMI. The primary endpoint was net adverse clinical events (NACE), a composite of major adverse cardiovascular events (MACE) and major bleeding events within one year after index PCI procedure. RESULTS: In the 720 patients, 180 patients (25.0%) had BMI value <21.3 kg/m2. While the rates of NACE and MACE were significantly higher in the Group 1 than the counterpart (21.1% vs. 11.9%, p = 0.003 and 17.2% vs. 8.9%, p = 0.004), that of major bleeding did not differ significantly between the 2 groups (5.6% vs. 4.3%, p = 0.54). The cumulative rate of NACE and MACE was significantly higher in the Group 1 than the Group 2 (both log-rank p = 0.002), although that of major bleeding events was equivalent between the 2 groups (log-rank p = 0.41). In multivariable Cox regression analyses, while BMI value <21.3 kg/m2 was not associated with major bleeding events, that cut-off value was an independent predictor for increased NACE and MACE. CONCLUSIONS: Among the patients undergoing PCI for CAD and requiring OAC for AF, BMI value was a useful indicator to predict major adverse clinical events.

Preliminary X-ray crystallographic study of staphylococcal α-haemolysin monomer.

Staphylococcal α-haemolysin is a ß-barrel pore-forming toxin expressed by Staphylococcus aureus. α-Haemolysin is secreted as a water-soluble monomeric protein which binds to target membranes and forms membrane-inserted heptameric pores. Although the crystal structures of the heptameric pore and monomer bound to an antibody have been determined, that of monomeric α-haemolysin without binder has yet to be elucidated. Previous mutation studies showed that mutants of His35 retain the monomeric structure but are unable to assemble into heptamers. Here, α-haemolysin H35A mutants were expressed, purified and crystallized. Diffraction data were collected to 2.90 Å resolution. The crystals belonged to space group P61, with unit-cell parameters a = b = 151.3, c = 145.0 Å. Molecular replacement found four molecules in an asymmetric unit. The relative orientation among molecules was distinct from that of the pore, indicating that the crystal contained monomeric α-haemolysin.

Coronary Artery Perforation After Balloon Dilatation for Recurrent In-Stent Restenosis Inside the Double-Layered Previous Stents.

Although coronary artery perforation can be a fatal complication during percutaneous coronary intervention, it is rarely observed in in-stent restenotic lesions. We present a case with coronary artery perforation after balloon dilatation for a recurrent in-stent restenotic lesion with calcified nodule inside the double-layered stents that were previously implanted. (Level of Difficulty: Advanced.).

Effect of two weeks of training cessation on concentric and eccentric knee muscle strength in highly trained sprinters.

Athletes often experience short-term training cessation because of injury, illness, post-season vacation, or other reasons. Limited information is available about the effect of short-term (less than four weeks) training cessation on muscle strength in athletes. Sprinting athletes must maintain knee extension and flexion strength to reduce the risk of sprint-type hamstring strain injury. This study aimed to identify whether and to what extent knee extension and flexion torque in concentric and eccentric contractions is reduced by two weeks of training cessation in sprinters. Before and after the training cessation, maximal voluntary isokinetic knee extension and flexion torque in slow and fast concentric (60 and 300°/s) and slow eccentric (60°/s) contractions were assessed in 13 young male highly trained sprinters (average World Athletics points = 978). Knee flexion torque during the bilateral Nordic hamstring exercise (NHE) was also measured. After the training cessation, isokinetic concentric at 300°/s and eccentric torque were significantly reduced in both knee extension and flexion. There was no difference in the magnitude of reduction between isokinetic knee extension and flexion torques in all conditions. The relative changes were more notable in eccentric (-15.0%) than in concentric contraction at 60°/s (-0.7%) and 300°/s (-5.9%). Knee flexion torque during the NHE also declined (-7.9% and -9.9% in the dominant and non-dominant legs, respectively). There was no significant correlation between the relative reductions in isokinetic knee flexion torque and knee flexion torque during the NHE. The findings suggest that sprinters and their coaches should focus on recovering fast concentric and slow eccentric knee extension and flexion strength after two weeks of training cessation.

Training cessation and subsequent retraining of a world-class female Olympic sailor after Tokyo 2020: A case study.

Olympic sailing is a complex sport where sailors are required to predict and interpret weather conditions while facing high physical and physiological demands. While it is essential for sailors to develop physical and physiological capabilities toward major competition, monitoring training status following the competition is equally important to minimize the magnitude of detraining and facilitate retraining. Despite its long history in the modern Olympics, reports on world-class sailors' training status and performance characteristics across different periodization phases are currently lacking. This case study aimed to determine the influence of training cessation and subsequent retraining on performance parameters in a world-class female sailor. A 31-year old female sailor, seventh in the Women's Sailing 470 medal race in Tokyo 2020, completely stopped training for 4 weeks following the Olympics, and resumed low-intensity training for 3 weeks. Over these 7 weeks, 12.7 and 5.3% reductions were observed in 6 s peak cycling power output and jump height, respectively, with a 4.7% decrease in maximal aerobic power output. Seven weeks of training cessation-retraining period induced clear reductions in explosive power production capacities but less prominent decreases in aerobic capacity. The current findings are likely attributed to the sailor's training characteristics during the retraining period.