Stand-up test could be a helpful adjunct for screening elbow disorders in Little League baseball players.

BACKGROUND: The purpose of this study is to justify the result of the modified Stand-Up test (MSUT) in Little League baseball players and to clarify the association with sports related disorders in the elbow. METHODS: A total of 245 (240 boys and 5 girls) Little League baseball players aged 9 to 12 underwent physical examination, elbow ultrasonography and questionnaires during a routine medical checkup. In addition, the MSUT, based on the Japanese Orthopaedic Association (JOA)'s original Stand-Up test to evaluate the risk of Locomotive syndrome, was performed. RESULTS: Seventeen osteochondritis dissecans (OCD) of capitellum and 4 medial epicondylar fragmentation (MEF) cases were diagnosed with ultrasonography in 242 players. Based on the MSUT, five boys could not stand up from 40 cm platform with the single leg stance, two of whom complained of current elbow pain, three of whom diagnosed with a positive finding with ultrasonography. Odds ratio (95% confidence limits) of risk factors for failing to the 40 cm-MSUT with the single leg stance were: incidence of current elbow pain 5.7 (0.9-35.5); OCD (Grade 1b and 2) 8.2 (0.8-83); and MEF 19.5 (1.7-230). CONCLUSION: Two percent of Little League baseball players were unable to stand up from a 40 cm high platform/stool with the single leg stance by the MSUT and it was associated with an increase in MEF or OCD diagnosis by ultrasonography and presence of elbow pain. These results suggest that players who failed to the 40 cm-MSUT with the single leg stance are at risk of elbow disorders. Also, these results are consistent with previous research on throwing injuries that have associated poor control in the legs or trunk with pain and injury involving the upper extremities. MSUT, a relatively simple procedure, may be a helpful adjunct for screening to estimate readiness for resuming general physical activity in Little League baseball players.

Bone parameters of elite athletes with oligomenorrhea and prevalence seeking medical attention: a cross-sectional study.

INTRODUCTION: Since the definition of secondary amenorrhea is cessation of regular menses for more than 3 months, it is likely that athletes with irregular menstrual cycles, including oligomenorrhea, do not consider the condition as serious. However, the consequences of untreated oligomenorrhea have not been investigated in elite track and field athletes. MATERIALS AND METHODS: The cohort consisted of 91 elite-level track and field athletes. Body compositions, including bone parameters and bone turnover markers (BTMs), were measured. RESULTS: Among the 91 participants, 52 were eumenorrheic and 33 were oligomenorrheic. The eumenorrheic athletes had significantly higher bone mineral density (BMD) and bone mineral content (BMC) of the lumbar spine, lower extremities, and whole body than had the oligomenorrheic athletes (p < 0.01). There were no significant differences in BTMs between the two groups, but oligomenorrheic athletes had significantly lower percent body fat. CONCLUSION: More than 40% of the elite-level female track and field athletes in this study reported menstrual disorders with oligomenorrhea as the most common. However, none sought medical attention. As compared to the eumenorrheic athletes, the oligomenorrheic athletes had lower BMC and BMD. Hence, if an athlete is oligomenorrheic, bone parameter measurements are considerably important.

Bone Metabolism, Bone Mineral Content, and Density in Elite Late Teen Female Sprinters.

With intensive training, bone injuries are a major concern for athletes. To assess bone condition, we often measure bone turnover markers, bone mineral content and density; however, in junior athletes, it is not easy to distinguish changes caused by bone injuries from those caused by growth, because the metabolism is increased in both cases. Moreover, although some studies have examined female endurance athletes, knowledge regarding changes in static and dynamic bone conditions in late teen athletes is limited. In this study, we measured the bone mineral content and density, as well as bone turnover markers, in 40 elite female sprinters in their late teens. Whole body mode dual-energy X-ray absorptiometry was performed to measure bone mineral content and density. Blood samples were collected to determine bone resorption and formation markers at the end of track season in 2016 and during the same period of the following year. Body weight and bone mineral content significantly increased, and tartrate-resistant acid phosphatase type 5b, bone-type alkaline phosphatase, and osteocalcin significantly decreased after a year. Furthermore, the rate of change in bone mineral content was higher in younger athletes, indicating that bone growth approaches completion in the late teen years and that bone metabolism accordingly decreases.

Bilateral suprascapular notches are asymmetrically shaped in a third of the Asian population.

PURPOSE: The side-to-side differences within an individual's suprascapular notch (SSN) and the clinical characteristics of an ossified superior transverse scapular ligament are unclear. Therefore, the morphological asymmetry of the SSN was investigated, and the factors associated with the ossification of the superior transverse scapular ligament were analyzed. METHODS: Two hundred and seventy-six computed tomography images were retrospectively analyzed, which included those of both scapulae of Asian patients (mean age, 62.1 ± 19.1 years; males, 197) with high-energy injuries or respiratory diseases. Variations in the SSN were classified into six types based on Rengachary's classification using reconstructed three-dimensional computed tomography. The group with a type VI SSN (completely ossified superior transverse scapular ligament) in at least one scapula was compared with the other group for age, sex, and chronic comorbidities. RESULTS: Among 276 patients, 95 (34.4%) had asymmetric SSNs and 15 (5.4%) had type VI SSNs. There were no significant differences in age, sex, or comorbidities between both the groups. However, on comparing age groups, the prevalence of type VI SSN was higher in patients aged > 70 years than in those aged < 70 years. Fifteen patients had type VI SSNs, which were unilateral in 10 patients. CONCLUSION: Asymmetric SSNs were observed in a third of the Asian patients. There were variations in SSNs between individuals and also within an individual. In the cases with suprascapular nerve paralysis, the difference in SSN morphology compared to a healthy side should be considered. LEVEL OF EVIDENCE: III.

The differences of humeral torsion angle and the glenohumeral rotation angles between young right-handed and left-handed pitchers.

BACKGROUND: The differences between young right-handed and left-handed baseball players are not well known. This study compared the range of the shoulder motion and humeral torsion angle (HTA) between right-handed and left-handed young baseball pitchers. METHODS: A total of 65 young baseball pitchers (age, 9-12 years; 46 right-handed throwers, R group; and 19 left-handed throwers, L group) were analyzed. The glenohumeral internal rotation (IR) angle and external rotation (ER) angle were measured at 90° shoulder abduction, and HTA was assessed using indirect ultrasonographic techniques. The side-to-side difference in HTA (d-HTA), glenohumeral ER difference (GERD), and glenohumeral IR deficit (GIRD) were calculated. The adjusted GIRD and adjusted GERD were defined as the angles obtained by subtracting d-HTA from GIRD and GERD, respectively, to exclude the influence of humeral retrotorsion difference. RESULTS: HTA and ER of the throwing limb were significantly greater than those of the nonthrowing limb in the R group (HTA: 84° vs. 77°; P < .001, ER: 116° vs. 111°; P < .001), but no significant differences were observed in the L group (HTA: 79° vs. 77°, P = .103; ER: 113° vs. 114°, P = .380). Compared with the R group, the L group showed a significantly smaller d-HTA (2° vs. 8°, P < .001) and GERD (5° vs. -2°, P = .004), but no significant difference was observed in adjusted GERD between the groups (-3° vs. -4°, P = .690). CONCLUSION: Compared with the right-handed pitchers, the side-to-side differences of glenohumeral external rotation angle and humeral torsion angle were significantly smaller in the left-handed pitchers at a young age.

Relationship between bilateral humeral retroversion angle and starting baseball age in skeletally mature baseball players-existence of watershed age.

BACKGROUND: Repetitive pitching in childhood was thought to restrict the physiological derotation process of the humeral head. Some studies reported that the side-to-side differences of humeral retroversion in baseball players occurred between the age of 9 and 11 years. The present study investigated the relationship between bilateral humeral retroversion angle and starting baseball age in skeletally mature baseball players. METHODS: One hundred and seventeen male baseball players, who belonged to a college or amateur team, were investigated. Bilateral humeral retroversion was assessed using an ultrasound-assisted technique as described by previous studies. All players were divided into four groups: players who had started playing baseball before the age of 6 years, between 7 and 8 years, between 9 and 10 years and after 11 years. Bilateral humeral retroversion angle was compared among the four starting age groups. RESULTS: All players started playing baseball between 5 and 12 years. Comparing the throwing arm, humeral retroversion in starting age group 11-12 (72°) was significantly smaller than the other 3 groups (81°, 82°, and 80° for groups 5-6, 7-8, and 9-10, respectively). Comparing the non-throwing arm revealed no significant differences among the 4 starting age groups (71°, 72°, 70°, and 66° for groups 5-6, 7-8, 9-10, and 11-12, respectively). CONCLUSIONS: Skeletally mature baseball players who started playing baseball after 11 years had significantly smaller humeral retroversion in the throwing arm than those who started baseball before 11 years.

Treatment of aneurysmal bone cysts using endoscopic curettage.

BACKGROUND: Although aneurysmal bone cysts (ABCs) are benign tumours, they have the potential to be locally aggressive. Various treatment approaches, such as en bloc resection, open curettage, radiotherapy, sclerotherapy, and embolization have been proposed, but the most appropriate treatment should be selected after considering the risk of tumour recurrence and treatment complications. Endoscopic curettage (ESC) may be a less invasive alternative to open curettage for ABC treatment. We aimed to describe the use of ESC for the treatment of ABCs and to report our clinical outcomes, including the incidence rate of recurrence, radiological appearance at final follow-up, time to solid union, complications, and postoperative function. METHODS: Between 1998 and 2015, 30 patients (18 men and 12 women; mean age, 17.4 years) underwent ESC for the treatment of primary ABCs at our hospital (mean postoperative follow-up, 55 months). ESC was performed under arthroscopic guidance for direct visualization, and curettage extended until normal bone was observed in the medullary cavity. To investigate bone healing after ESC, we evaluated the consolidation of cysts at the final evaluation (based on the modified Neer classification) and time to solid union after surgery, which was defined as sufficient cortical bone thickness to prevent fracture and allow physical activities. RESULTS: Recurrence was identified in 3 cases (10%). Curative outcomes were obtained after repeated ESC or open curettage. A log-rank analysis indicated that age < 10 years (p = 0.004) and contact of the tumour with the physis (p = 0.01) increased the risk of tumour recurrence. Residual tumours were identified in 9 cases (30%); these lesions remained inactive over the extended follow-up period. The average time to solid union after endoscopic curettage was 3.2 months. Transient radial nerve palsy was identified in 1 case. Good postoperative functional recovery occurred in all cases. CONCLUSIONS: ESC is a minimally invasive technique for the treatment of ABCs, and the tumour recurrence rate is comparable to that of other standard procedures. However, the application of this method should be carefully considered, especially for patients < 10 years and when the tumour comes in contact with the physis.

Sonographic sequential change of the anteroinferior labrum following arthroscopic Bankart repair: quantitative and qualitative assessment.

OBJECTIVE: Although arthroscopic Bankart repair is widely performed, little is known concerning the healing process of the Bankart lesion. This study aimed to describe the sonographic sequential change of the anteroinferior labrum following arthroscopic Bankart repair, both quantitatively and qualitatively. MATERIALS AND METHODS: Twenty-five subjects who had undergone arthroscopic Bankart repair were investigated using a sonographic diagnostic device equipped with shear-wave elastographic technology. In addition to measuring the elasticity of the anteroinferior labrum, the B-mode echogram of the anteroinferior labrum was classified into three grades based on the relative echogenicity. Assessment was performed in the affected shoulder 1, 2, 3, 4, 5, 6, and 12 months postoperatively and in the contralateral shoulder 1 month postoperatively for the control. RESULTS: The mean elasticity of the anteroinferior labrum in the affected shoulder 1 and 2 months postoperatively was significantly lower than in the contralateral shoulder (p < 0.001 for both). However, no significant difference was found after 3 months postoperatively. B-mode echograms of the anteroinferior labrum in the contralateral shoulder were classified as grade 0 in all subjects (100%), whereas the percentage of grade 0s in the affected shoulder was 0, 4, 96, and 100% at 1, 2, 3, and 4 months postoperatively. CONCLUSION: Both quantitative and qualitative assessment of repaired anteroinferior labrum using ultrasound became comparable with the contralateral shoulder 3-4 months postoperatively. Ultrasound is a useful decision-supporting tool to prescribe postoperative rehabilitation protocol following arthroscopic Bankart repair, although functional recovery should also be evaluated on an individual basis.

Post-operative rotator cuff integrity, based on Sugaya's classification, can reflect abduction muscle strength of the shoulder.

PURPOSE: Magnetic resonance (MR) imaging is common in structural and qualitative assessment of the rotator cuff post-operatively. Rotator cuff integrity has been thought to be associated with clinical outcome. The purpose of this study was to evaluate the inter-observer reliability of cuff integrity (Sugaya's classification) and assess the correlation between Sugaya's classification and the clinical outcome. It was hypothesized that Sugaya's classification would show good reliability and good correlation with the clinical outcome. METHODS: Post-operative MR images were taken two years post-operatively, following arthroscopic rotator cuff repair. For assessment of inter-rater reliability, all radiographic evaluations for the supraspinatus muscle were done by two orthopaedic surgeons and one radiologist. Rotator cuff integrity was classified into five categories, according to Sugaya's classification. Fatty infiltration was graded into four categories, based on the Fuchs' classification grading system. Muscle hypotrophy was graded as four grades, according to the scale proposed by Warner. The clinical outcome was assessed according to the constant scoring system pre-operatively and 2 years post-operatively. RESULTS: Of the sixty-two consecutive patients with full-thickness rotator cuff tears, fifty-two patients were reviewed in this study. These subjects included twenty-three men and twenty-nine women, with an average age of fifty-seven years. In terms of the inter-rater reliability between orthopaedic surgeons, Sugaya's classification showed the highest agreement [ICC (2.1) = 0.82] for rotator cuff integrity. The grade of fatty infiltration and muscle atrophy demonstrated good agreement, respectively (0.722 and 0.758). With regard to the inter-rater reliability between orthopaedic surgeon and radiologist, Sugaya's classification showed good reliability [ICC (2.1) = 0.70]. On the other hand, fatty infiltration and muscle hypotrophy classifications demonstrated fair and moderate agreement [ICC (2.1) = 0.39 and 0.49]. Although no significant correlation was found between overall post-operative constant score and Sugaya's classification, Sugaya's classification indicated significant correlation with the muscle strength score. CONCLUSIONS: Sugaya's classification showed repeatability and good agreement between the orthopaedist and radiologist, who are involved in the patient care for the rotator cuff tear. Common classification of rotator cuff integrity with good reliability will give appropriate information for clinicians to improve the patient care of the rotator cuff tear. This classification also would be helpful to predict the strength of arm abduction in the scapular plane. LEVEL OF EVIDENCE: IV.

Anterior and posterior bands of the anterior bundle in the elbow ulnar collateral ligament: ultrasound anatomy.

BACKGROUND: The anterior oblique bundle (AOL) of the ulnar collateral ligament (UCL) is composed of anterior and posterior bands. This study evaluated the anatomy of the anterior and posterior bands in the AOL of the UCL for their separate visualization with ultrasound (US). METHODS: We dissected 18 cadaveric elbow joints and recorded the direction of each band from the lateral view to determine the proper position for the US transducer. To determine the proper inclination of the transducer, we measured the inclinations of each band at the proximal and distal insertions from the transverse view. A paired t test was used for comparisons between both bands. Values of P < .05 were considered statistically significant. RESULTS: The mean angles of the directions in the anterior and posterior bands were 10° ± 4° and 24° ± 9°, respectively. At the medial epicondyle, the mean inclination angles of both bands were 61° ± 5° and 67° ± 5°, respectively. At the sublime tubercle, the mean inclination angles of both bands were 14° ± 7° and 44° ± 9°, respectively. The inclination angles at the proximal ulna and the directions in both bands were significantly different (P < .001). CONCLUSIONS: This study shows that the directions of both bands and inclination angles of the bony attachments in both bands can assist with correct placement of the US transducer and allow for separate visualization of each band.

Left-handed skeletally mature baseball players have smaller humeral retroversion in the throwing arm than right-handed players.

BACKGROUND: It is known that the humeral retroversion of baseball players is greater in the throwing arm than in the nonthrowing arm. An investigation measuring dry bone specimens also showed that the right humerus had greater retroversion than the left. Considering these facts, it was hypothesized that humeral retroversion would differ between right- and left-handed players. This study aimed to compare the bilateral humeral retroversion between right- and left-handed skeletally mature baseball players. METHODS: We investigated 260 (196 right-handed and 64 left-handed) male baseball players who belonged to a college or amateur team. Bilateral humeral retroversion was assessed using an ultrasound-assisted technique (humeral torsion angle [HTA]) as described by previous studies. Analysis of covariance, adjusted for handedness and baseball position, assessed the effect of throwing arm dominance on HTA. RESULTS: In comparison of the throwing arm, HTA was significantly smaller in left-handed (left humerus) than in right-handed (right humerus) players (77° vs. 81°; P < .001). In comparison of the nonthrowing arm, HTA was significantly greater in left-handed (right humerus) than in right-handed (left humerus) players (73° vs. 69°; P < .001). The mean side-to-side difference of HTA was significantly smaller in left-handed than in right-handed players (3° vs. 12°; P < .001). CONCLUSIONS: Humeral retroversion of left-handed skeletally mature baseball players was significantly smaller in the throwing arm, greater in the nonthrowing arm, and smaller in side-to-side differences than that of right-handed players. These findings may be key to understanding some of the biomechanical differences between right- and left-handed baseball players.

Comparison of quantitative evaluation between cutaneous and transosseous inertial sensors in anterior cruciate ligament deficient knee: A cadaveric study.

BACKGROUND: Recently several authors have reported on the quantitative evaluation of the pivot-shift test using cutaneous fixation of inertial sensors. Before utilizing this sensor for clinical studies, it is necessary to evaluate the accuracy of cutaneous sensor in assessing rotational knee instability. To evaluate the accuracy of inertial sensors, we compared cutaneous and transosseous sensors in the quantitative assessment of rotational knee instability in a cadaveric setting, in order to demonstrate their clinical applicability. METHODS: Eight freshly frozen human cadaveric knees were used in this study. Inertial sensors were fixed on the tibial tuberosity and directly fixed to the distal tibia bone. A single examiner performed the pivot shift test from flexion to extension on the intact knees and ACL deficient knees. The peak overall magnitude of acceleration and the maximum rotational angular velocity in the tibial superoinferior axis was repeatedly measured with the inertial sensor during the pivot shift test. Correlations between cutaneous and transosseous inertial sensors were evaluated, as well as statistical analysis for differences between ACL intact and ACL deficient knees. RESULTS: Acceleration and angular velocity measured with the cutaneous sensor demonstrated a strong positive correlation with the transosseous sensor (r = 0.86 and r = 0.83). Comparison between cutaneous and transosseous sensor indicated significant difference for the peak overall magnitude of acceleration (cutaneous: 10.3 ± 5.2 m/s2, transosseous: 14.3 ± 7.6 m/s2, P < 0.01) and for the maximum internal rotation angular velocity (cutaneous: 189.5 ± 99.6 deg/s, transosseous: 225.1 ± 103.3 deg/s, P < 0.05), but no significant difference for the maximum external rotation angular velocity (cutaneous: 176.1 ± 87.3 deg/s, transosseous: 195.9 ± 106.2 deg/s, N.S). CONCLUSIONS: There is a positive correlation between cutaneous and transosseous inertial sensors. Therefore, this study indicated that the cutaneous inertial sensors could be used clinically for quantifying rotational knee instability, irrespective of the location of utilization.

Quantitative analysis of attachment of the labrum to the glenoid fossa: a cadaveric study.

PURPOSE: This study investigated the direct and continuous attachment of the labrum to the glenoid fossa, including the fibrocartilaginous tissue, using image-analysis software and histology. METHODS: Twenty-six cadaveric shoulders (11 male, 15 female; mean age 80.1 years; age range 36-103 years) were used. The glenoid of each specimen was divided into six pie-slice-shaped pieces from the center perpendicular to the articular surface by radial incisions at the 2, 4, 6, 8, 10, and 12 o'clock positions. The general distribution of the labrum, including the fibrocartilage, was assessed in hematoxylin and eosin-, Safranin O- and Azan-Mallory-stained sections. The continuous length of attachment of the labrum to the glenoid was measured using image-analysis software. The width of attachment to the articular surface of the glenoid was assessed in each position. RESULTS: The labrum attached to both the articular surface and the neck of the glenoid in all shoulders (100 %) in the 4 and 6 o'clock positions. The mean length of the entire attachment to the glenoid was 4.6 mm (range 3.2-6.1 mm). The width of attachment from the bony edge of the glenoid to the edge of the labrum on the articular surface ranged from 0 to 4.3 mm. The length of the entire attachment of the labrum was shortest in the 2 o'clock position (p = 0.229). Additionally, the length of the entire attachment of the labrum was longest in the 4 o'clock position. The width of attachment to the articular surface of the glenoid was greatest in the 4 o'clock position (p < 0.01). CONCLUSION: In the 4 and 6 o'clock positions, the labrum attached to both the articular surface and neck of the glenoid in all of the shoulders (100 %). The length of the entire attachment to the labrum, including the fibrocartilage, was shortest in the 2 o'clock position. The width of attachment to the articular surface of the glenoid was greatest in the 4 o'clock position (p < 0.01).

Postoperative evaluation of drill holes for arthroscopic Bankart repair with suture anchors by the use of computed tomography.

BACKGROUND: Here we investigated the angle and placement of bone holes for suture anchors using postoperative computed-tomography scapula scans. METHODS: The study group comprised 20 shoulders from 20 consecutive patients (13 males and seven females; mean age 23.4 years) who underwent arthroscopic Bankart repair. All anchors were inserted through the anterior portal after establishing a bone hole at the edge of the glenoid articular surface using a drill. Computed tomography images of the scapula were taken 1 month postoperatively and used to create three-dimensional scapula models with Mimics and Magics software. Bone holes in the anterior-inferior (3:00-6:00) position were assigned either to the non-perforated group if they were positioned entirely inside the glenoid bone or to the perforated group if the far cortex of the glenoid was penetrated by the drill. The angle between the glenoid articular surface and the bone hole was measured in the oblique coronal and transverse plane views. The length of the bone hole was also assessed. RESULTS: Of the 85 bone holes investigated, 42 were in the 3:00-6:00 position. Perforation was detected in 16 of these 42 holes (38.2%). The angle in the oblique coronal plane view and the length of the bone hole were significantly larger in the non-perforated group than in the perforated group; however, the angle in the transverse plane view did not significantly differ between the two groups. CONCLUSIONS: Before inserting an implant in the anterior-inferior area, the angle between the drill guide and the glenoid surface in the oblique coronal plane view should be carefully checked to ensure that the length of the hole inside the glenoid bone is adequate.

RECQL4 is essential for the transport of p53 to mitochondria in normal human cells in the absence of exogenous stress.

Mutations in RECQL4 helicase are associated with Rothmund-Thomson syndrome (RTS). A subset of RTS patients is predisposed to cancer and is sensitive to DNA damaging agents. The enhanced sensitivity of cells from RTS patients correlates with the accumulation of transcriptionally active nuclear p53. We found that in untreated normal human cells these two nuclear proteins, p53 and RECQL4, instead colocalize in the mitochondrial nucleoids. RECQL4 accumulates in mitochondria in all phases of the cell cycle except S phase and physically interacts with p53 only in the absence of DNA damage. p53-RECQL4 binding leads to the masking of the nuclear localization signal of p53. The N-terminal 84 amino acids of RECQL4 contain a mitochondrial localization signal, which causes the localization of RECQL4-p53 complex to the mitochondria. RECQL4-p53 interaction is disrupted after stress, allowing p53 translocation to the nucleus. In untreated normal cells RECQL4 optimizes de novo replication of mtDNA, which is consequently decreased in fibroblasts from RTS patients. Wild-type RECQL4-complemented RTS cells show relocalization of both RECQL4 and p53 to the mitochondria, loss of p53 activation, restoration of de novo mtDNA replication and resistance to different types of DNA damage. In cells expressing Δ84 RECQL4, which cannot translocate to mitochondria, all the above functions are compromised. The recruitment of p53 to the sites of de novo mtDNA replication is also regulated by RECQL4. Thus these findings elucidate the mechanism by which p53 is regulated by RECQL4 in unstressed normal cells and also delineates the mitochondrial functions of the helicase.

Ultrasound imaging of the humeral capitellum: a cadaveric study.

BACKGROUND: Ultrasound is suitable for routine examinations of capitellar osteochondritis dissecans because it can visualize both the subchondral bone and the overlying articular cartilage non-invasively. The radial head interferes with the sonographically visible area of the articular surface of the humeral capitellum, although the precise extent of this is currently unknown. This study aimed to investigate the visible area of the humeral capitellum using both anterior and posterior ultrasonographic scans. METHODS: Twelve elbows were used from cadavers with a mean age of 85.6 years. After marking a 45° angle in the anterior capitellum in a caudal direction using a drill, anterior and posterior, long-axis ultrasonographic scans were performed with the cadaveric elbows bent. The elbow-flexion angle at which the 45° point was obscured by the radial head was measured and these ultrasonic measurements were then verified by macroscopic observation. RESULTS: The elbow-flexion angle at which the 45° point was obscured by the radial head was 24° in anterior scans and 102° in posterior scans. These ultrasonic measurements corresponded to the macroscopic measurements. The results showed that anterior, long-axis ultrasound scans could visualize the capitellum from 45° through the rest of the anterior area at 24° flexion of the elbow: the radial head obscured the area of the capitellum that is 21° anterior to the elbow flexion angle. Similarly, posterior long-axis scans could visualize the capitellum from 45° through the rest of the posterior area at 102° flexion of the elbow: the radial head obscured the area of the capitellum that is 57° posterior to the elbow flexion angle. The radial head obscured a 78° (21° + 57°) arc of the capitellum in ultrasonography. CONCLUSIONS: This study thus clarified the area of the humeral capitellum visible in both anterior and posterior ultrasound scans in the sagittal plane.

C-terminal processing of tyrosinase is responsible for activation of Pholiota microspora proenzyme.

Tyrosinase is expressed as a 67-kDa protein in Pholiota microspora (synonym Pholiota nameko), whereas the same enzyme purified from fruiting bodies of P. microspora is a 42-kDa protein that is cleaved with a C-terminal 25-kDa polypeptide from the 67-kDa protein. To confirm the role of C-terminal processing in enzyme activity, we expressed a recombinant 67-kDa tyrosinase in Escherichia coli cells. To obtain a soluble protein, the recombinant tyrosinase was expressed as a thioredoxin fusion protein with an enterokinase-cleavable site. Enterokinase digestion of the fusion protein produced a recombinant 67-kDa tyrosinase that did not have any catalytic activity. However, chymotrypsin digestion of the fusion protein produced a recombinant 44-kDa tyrosinase that was catalytically active and had a 25-kDa cleaved C-terminal. Kinetic parameters of the 44-kDa tyrosinase were similar to those of the 42-kDa tyrosinase purified from the fruiting bodies. These results suggest that tyrosinase is expressed in P. microspora as a latent 67-kDa proenzyme and is converted to the mature active 42-kDa enzyme by proteolytic processing of the C-terminal.

Changes in Body Composition and Its Relationship to Performance in Elite Female Track and Field Athletes Transitioning to the Senior Division.

Many elite female athletes struggle to maintain performance while transitioning from high school to university-level (senior) sports. This study explores factors of body composition that influenced performance in elite junior female track and field athletes transitioning to the senior division. Forty-two elite female track and field athletes, ranked among the top 100 in Japan, were enrolled in this study. Whole-body mode dual-energy X-ray absorptiometry scans were performed during the post-season of 2016 and 2017. Athletes' performances were assessed using the International Association of Athletics Federation scoring system. Relationships between changes in performance and those in body composition were investigated. There were significant negative correlations between changes in performance and fat mass (FM), and percentage FM (FM%). This was seen in total body and lower extremities, and not in the trunk and upper extremities. In addition, there was a positive correlation between changes in performance and percentage lean mass (LM%). However, there were no correlations between changes in performance and LM and total mass. Elite female track and field athletes transitioning to senior division should decrease their FM and FM% and increase LM%, to sustain or improve performance. It is also more important to monitor changes in body composition than body mass.

Characteristics of Femoral Torsion Angles and Relationships Between Femoral Torsion Angles and Hip Rotational Motion Variables in Adult Baseball Players.

BACKGROUND: Abnormalities in hip rotational motion (HRM) are risk factors for throwing injuries. To evaluate hip rotational motion, it is necessary to assess the torsion angle. However, no studies have investigated the femoral torsion angle (FTA) in baseball players. PURPOSE: To investigate differences in hip FTA of adult baseball players through use of ultrasonography to evaluate the relationship between the FTA and HRM. STUDY DESIGN: Cross-sectional study; Level of evidence, 3. METHODS: A total of 149 elite male baseball players (mean age, 20.0 ± 1.8 years; 64 pitchers, 85 position players) were enrolled in this study. Ultrasonographic assessment of FTA was performed based on the tilting angles of the anterior surface of the femoral neck and condylar axis. The hip internal rotation (HIR) and hip external rotation (HER) were assessed at 0° and 90° of flexion. Data related to FTA and HRM were compared between hips and between pitchers and position players. RESULTS: No significant difference was observed in the FTAs between hips for any player (lead hip, 20.5° ± 9.2°; trail hip, 19.6° ± 9.8°; P = .276). No significant difference was observed in FTAs of both hips between pitchers and position players (lead hip, 20.1° ± 9.4° and 20.9° ± 9.0°, respectively, P = .957; trail hip, 19.5° ± 9.8° and 19.7° ± 9.8°, P = .999). In terms of HER in 90° of hip flexion in both hips, significant differences were observed in HRM variables between pitchers and position players (lead hip, 33.0° ± 8.9° and 37.5° ± 9.8°, respectively, P = .024; trail hip, 35.6° ± 9.6° and 40.4° ± 10.2°, P = .035). Linear regression analysis revealed a significant agreement between the FTA and HIR at both 0° (R = 0.298, P < .001) and 90° of hip flexion (R = 0.279, P < .001). CONCLUSION: Our findings indicated that FTAs were not different between the hips of elite baseball players. Abnormalities of the HRM are not caused by differences in the FTA but rather involve soft tissue tightness around the hip area or other bony morphologic factors in the hip joint.

Discovery of novel 2',3',4'-trihydroxy-2-phenylacetophenone derivatives as anti-gram-positive antibacterial agents.

A number of 2',3',4'-trihydroxy-2-phenylacetophenone derivatives were synthesized and examined for growth inhibition of several kinds of bacteria. 2',3',4'-Trihydroxy-2-phenylacetophenone itself exhibited no antibacterial activity, but some of its derivatives showed various antibacterial activities depending on functional groups introduced on the 2-phenyl ring. Eighteen out of 24 compounds synthesized in this study appeared to possess antibacterial activities against at least two Gram-positive strains of Bacillus subtilis and Staphylococcus aureus, 2-(biphenyl-4-yl)-2',3',4'-trihydroxyacetophenone being the most active with LC(50) of 5.8 muM and 5.6 muM respectively. However, none of the synthesized compounds exhibited inhibitory effects on Gram-negative strains, such as Escherichia coli, Proteus mirabilis, Pseudomonas aeruginosa, and Salmonella enterica, suggesting that anti-Gram-positive specificity of the antibacterial compounds.