New gel immersion endoscopic ultrasonography technique for accurate periampullary evaluation.

BACKGROUND: Visualization of the pancreatobiliary junction is one of the challenges faced by endoscopic ultrasonography (EUS). The water-filling technique, which allows for the observation of the ampulla at a suitable distance by injecting water into the lumen of the duodenum, was used for this purpose. However, a new gel immersion technique has recently been introduced for visualizing the gastrointestinal tract. This study investigated the effectiveness of visualizing the pancreatobiliary junction in EUS by comparing both water filling and the new gel immersion technique in identical cases. METHODS: The study ran from June to December 2021. Ten images from each technique were retrospectively compared by three independent researchers. The primary result of the study was the number of images depicting the "Pancreatic and Biliary Ducts Penetrating the Duodenal Muscularis Propria" (defined as Excellent observation) in each technique. The secondary outcome was defined as gel immersion technique's safety and impact on duodenal lumen distension. RESULTS: Ten patients used the gel immersion technique. All patients underwent the water-filling technique first, followed by gel injection after the water was completely aspirated. The average number of pictures rated as "Excellent observation," which is the primary outcome, was significantly higher with the gel immersion technique than with water filling, and no adverse events were observed. The subanalysis revealed that both convex and radial echoendoscopes are equally effective at depicting the ampulla with the gel immersion technique. CONCLUSIONS: The ability to depict the pancreatobiliary junction using the gel immersion technique is superior to that of the water-filling method, which may allow for a more detailed assessment of the ampullary region with both radial and convex echoendoscopes. This can be a useful EUS technique for diagnosing pancreaticobiliary maljunction or periampullary tumors.

Inhibition of melanoma cell proliferation by strobilurins isolated from mushrooms and their synthetic analogues.

Strobilurins A and X, isolated from Mucidula venosolamellata culture extracts, demonstrated potent inhibition of human melanoma G-361 cell proliferation. Strobilurin X exhibited milder inhibitory effects on human fibroblast cells (NB1RGB) compared to strobilurin A. Additional strobilurin-related compounds were isolated from the other mushroom species. Oudemansins A and B displayed weaker activities on G-361 cells than strobilurins A and B, respectively, emphasizing the importance of a conjugated double-bond structure. Among isolated compounds, strobilurin G showed the lowest IC50 value for G-361 cells. Additional strobilurins bearing various substituents on the benzene ring were synthesized. Synthetic intermediates lacking the methyl ß-methoxyacrylate group and a strobilurin analogue bearing modified ß-methoxyacrylate moiety showed almost no inhibitory activity against G-361 cells. The introduction of long or bulky substituents at the 4' position of the benzene ring of strobilurins enhanced the activity and selectivity, suggesting differential recognition of the benzene ring by G-361 and NB1RGB cells.

Variability in sonographic anterior drawer test measurements of the ankle: Experienced versus beginner examiners.

BACKGROUND: This study aimed to clarify the variability in the measurements of stress sonography of the ankle and determine the effects of examiner experience on the measurements. METHODS: Twenty examiners (10 experienced and 10 beginners) were included in the study. Each examiner performed stress ultrasonography on a patient with a chronic anterior talofibular ligament injury and a patient with an intact ligament using the reverse anterior drawer method. Changes in ligament length before versus after stress were determined. The same 20 examiners performed ultrasonography on two other patients with an injured or intact ATFL using the anterior drawer method. The length change values and variance were compared between the groups using t-tests and F-tests. RESULTS: Using the reverse anterior drawer method, the change in the anterior talofibular ligament length was 3.3 mm (range, 2.2-4.8 mm) in the experienced group and 2.7 mm (0.0-4.1 mm) in the beginner group for the ligament injured patient. The length changes for the patient with intact anterior talofibular ligament were 0.5 mm (0.1-0.9 mm) and 0.4 mm (-0.1-1.5 mm) in the experienced and beginner groups, respectively. There were no significant intergroup differences in measurement amount (P = 0.37) or variance (P = 0.72). Similarly, using the anterior drawer method, no significant differences between the groups were found in measurement amount or variance. CONCLUSION: The quantitative evaluation of stress sonography of the ankle was variable regardless of examiner experience or stress method, particularly in patients with an anterior talofibular ligament injury. The amount of variability appeared to be unacceptably large for clinical application. Our study results highlight the need for technical standardization.

Enhancing Cartilage Metabolism in Rats through a Novel Thermal Stimulation Technique with Photosensitizers.

Although the moderate thermal stimulation of articular cartilage exerts chondroprotective effects, it is difficult to effectively heat deep articular cartilage with conventional methods. Photosensitizers increase the ambient temperature using near-infrared (NIR) radiation, which has high tissue permeability. We hypothesized that the intra-articular administration of photosensitizers and NIR irradiation would exert a greater heating effect on articular cartilage. We aimed to evaluate the heating effect of this method on cultured chondrocytes and rat knee cartilage. In vitro, we irradiated a photosensitizer-containing medium with NIR and measured changes in the medium temperature, cytotoxicity, and gene expression of heat shock protein (HSP) 70 and aggrecan (ACAN). In vivo, the knee joints of rats treated with photosensitizers were irradiated with NIR, and changes in intra-articular temperature and gene expression were measured, alongside histological analysis. The results showed that the medium and intra-articular temperature were raised to approximately 40 °C with no apparent disruption to articular cartilage or the immunohistochemically enhanced staining of HSP70 in chondrocytes. The gene expression of HSP70 and ACAN was increased in both cultured and articular cartilage. In summary, this method can safely heat joints and enhance cartilage metabolism by inducing HSP70 expression in articular cartilage. It presents a new hyperthermia therapy with effective cartilage protection.

Relationship between arthritis of the second and third tarsometatarsal joints and incongruity of the first tarsometatarsal joint in patients with hallux valgus.

OBJECTIVES: Hallux valgus is associated with tarsometatarsal arthritis; its pathophysiology remains unknown. Therefore, we aimed to elucidate the relationship between arthritis of the second and third tarsometatarsal joints and incongruity of the first tarsometatarsal joint in the sagittal plane. METHODS: Forty-three patients (64 feet) with hallux valgus who underwent surgery at University Hospital Kyoto Prefectural University of Medicine were included and divided into two groups: control (without second and third tarsometatarsal joint degeneration) and osteoarthritis (with second and third tarsometatarsal joint degeneration). Intergroup comparisons of the incongruity of the first tarsometatarsal joint in the sagittal plane, age, body mass index, hallux valgus angle, first-second intermetatarsal angle, metatarsus adductus angle, Meary's angle, and calcaneal pitch angle were performed. RESULTS: The proportion of patients with incongruity of the first tarsometatarsal joint was significantly higher in the osteoarthritis group than in the control group. Logistic regression analysis identified incongruity of the first tarsometatarsal joint and metatarsus adductus angle as significant related factors for arthritis of the second and third tarsometatarsal joints. CONCLUSIONS: Incongruity of the first tarsometatarsal joint in the sagittal plane was involved in the development of arthritis of the second and third tarsometatarsal joints in patients with hallux valgus.

Posterior Occipitocervical Fixation and Intrathecal Baclofen Therapy for the Treatment of Basilar Invagination with Klippel-Feil Syndrome: A Case Report.

Klippel-Feil syndrome (KFS) is characterized by the congenital fusion of the cervical vertebrae and is sometimes accompanied by anomalies in the craniocervical junction. In basilar invagination (BI), which is a dislocation of the dens in an upper direction, compression of the brainstem and cervical cord results in neurological defects and surgery is required. A 16-year-old boy diagnosed with KFS and severe BI presented with spastic tetraplegia, opisthotonus and dyspnea. CT scans showed basilar impression, occipitalization of C1 and fusion of C2/C3. MRI showed ventral compression of the medullocervical junction. Posterior occipitocervical reduction and fusion along with decompression were performed. Paralysis gradually improved postoperatively over 3 weeks. However, severe spasticity and opisthotonus persisted and intrathecal baclofen (ITB) therapy was initiated. Following this, opisthotonus disappeared and spasticity of the extremities improved. Rehabilitation therapy continued by controlling the dose of ITB. Five years after the surgery, self-propelled wheelchair driving was achieved and activities of daily life improved. The treatment strategy for patients with BI and congenital anomalies remains controversial. Posterior reduction and internal fixation using instrumentation were effective techniques in this case. Spasticity control achieved through a combination of surgery and ITB treatment enabled the amelioration of therapeutic efficacy of rehabilitation and the improvement of ADL.

Ionic Liquids as Organocatalysts and Solvents for Lignocellulose Reactions.

Ionic liquids (ILs) are the only media that can allow the homogeneous organocatalytic reactions of lignocellulosic biomass (lignocellulose), since the designability of their cations and anions offers the dual functions of solubility and catalytic activity. This review provides an account of our recent achievements in the organocatalytic approaches for converting lignocellulose into polymer materials based on the principles of IL design that we have originally established. These methodologies include the simple and mild chemical modification of cellulose and lignin under high conversions, with high selectivity, and/or with efficient atom economy. Similar reactions and subsequent fractionation processes are applied to lignocellulose, and a highly productive reaction system is developed using a twin-screw extruder that is specific to the IL media.

Quantitative Analysis of Ultrasonography for de Quervain's Disease: Comparison of the Affected Side With the Asymptomatic Side.

OBJECTIVES: The pathology of de Quervain's disease affects the tenosynovium and rarely the tendons. The ultrasonographic features of de Quervain's disease unresponsive to conservative treatment are unknown. The purpose of this study was to describe and compare the morphological differences between patients with de Quervain's disease that is refractory to conservative treatment and patients who respond to conservative treatment. METHODS: de Quervain's disease unresponsive to conservative treatment was evaluated in 51 patients. The bilateral wrists underwent preoperative ultrasonographic assessments. The asymptomatic side was presumed to be the patient's anatomical baseline and was used for comparison. We measured the diameter and cross-sectional area of the tendons of the abductor pollicis longus (APL) and extensor pollicis brevis (EPB), and the thickness of the tendon sheath and the intercompartmental septum, if present. The affected side and asymptomatic side were compared. RESULTS: The APL and EPB cross-sectional area was significantly larger on the affected side than on the asymptomatic side (APL: 13 mm2 versus 8.3 mm2 ; P < .0001; EPB: 5.4 mm2 versus 3.9 mm2 ; P = .031). The tendon sheath was significantly thicker on the affected side (1.5 mm) than on the asymptomatic side (0.95 mm) (P < .0001). The intercompartmental septum was significantly thicker on the affected side (1.1 mm) than on the asymptomatic side (0.72 mm) (P = .0004). Operative findings revealed 41 (80%) patients had an intercompartmental septum. CONCLUSIONS: The ultrasonographic features of de Quervain's disease requiring surgical treatment were a significantly thickened tendon sheath, an intercompartmental septum, and increased cross-sectional area of the APL and EPB.

The inter-prefectural regional disparity of healthcare resources and representative surgical procedures in orthopaedics and general surgery: a nationwide study in Japan during 2015-2019.

BACKGROUND: Few reports have examined the localized regional disparity in representative surgical procedures in orthopaedics and general surgery globally. This study aimed to clarify the inter-prefectural regional disparity and relationships between healthcare resources and representative surgical procedures using a nationwide database in Japan. METHODS: The number of medical specialists in orthopaedics, general surgery, and anaesthesiology, as well as the number of hospitals, and the incidence of representative surgical procedures in orthopaedics and general surgery were evaluated annually per 100,000 inhabitants/people by prefecture in Japan during 2015-2019. Medium-sized regional disparities were evaluated using the Gini coefficient. Correlation coefficients were calculated for the defined variables and ageing rate. We also compared the urban and rural regional disparities in all study variables. RESULTS: The annual average number/incidence and Gini coefficients were 110.6 and 0.11 for femur fracture surgery, 106.3 and 0.09 for cholecystectomy, 14.2 and 0.11 for orthopaedic surgeon specialists, 17.6 and 0.09 for general surgeon specialists, 5.9 and 0.13 for anaesthesiology specialists, and 8.1 and 0.21 for hospitals, respectively. The correlation coefficients by the incidence of femur fracture surgery were 0.74 for orthopaedic surgeon specialists (p < 0.001), 0.63 for hospitals (p < 0.001), and 0.62 for the ageing rate (p < 0.001); those by the incidence of cholecystectomy were 0.60 for general surgeon specialists (p < 0.001) and 0.59 for hospitals (p < 0.001). The number/incidence of orthopaedic surgeon specialists, hospitals, femur fracture surgery, and cholecystectomy, as well as the ageing rate, were significantly higher in rural prefectures than in urban prefectures (p < 0.05). CONCLUSIONS: Inter-prefectural regional disparity was small, although certain items were unevenly distributed in the rural prefectures, which is contrary to our expectations. Higher prevalence was recognised in rural prefectures due to the higher ageing rate; however, supply and demand are balanced. This study provides basic data for healthcare policy development in a medium-sized community. LEVEL OF EVIDENCE: III.

Focused Extracorporeal Shock Wave Therapy for Ischial Apophysitis in Young High-Level Gymnasts.

OBJECTIVE: We aimed to investigate the effect and safety of extracorporeal shock wave therapy (ESWT) on ischial apophysitis (IA) in young high-level gymnasts. We hypothesized that ESWT would be safe and effective in alleviating pain. DESIGN: Retrospective case series. SETTING: Funabashi Orthopedic Hospital. PATIENTS: The subjects were 18 high-level gymnasts (mean age of 13 years) with a chief complain of chronic buttock pain diagnosed with IA. INTERVENTIONS: Ten patients received only physiotherapy (PT), whereas 8 received both PT and ESWT to the ischial tuberosity. The basic protocol for ESWT was to use an energy dose of 0.20 mJ/mm 2 or less with 3000 shots per session at 4-week intervals. MAIN OUTCOME MEASURES: We investigated whether PT and ESWT relieved the pain and allowed the patient to return fully to gymnastics. Based on radiographs at the last observation, we examined whether early closure of the apophyseal line of the ischium and around hip joint on the affected side occurred. RESULTS: In the PT group, pain was relieved in 2 of 10 patients. In the ESWT group, pain was relieved and full return to gymnastics was possible in all 8 patients. None of the patients showed early closure of the apophyseal line. CONCLUSIONS: Extracorporeal shock wave therapy can be a safe and effective treatment option for IA in young high-level gymnasts.

Efficacy of biceps-radial-slice magnetic resonance images for the diagnosis of biceps and pulley lesions.

BACKGROUND: Injuries to the biceps reflection pulley lead to instability of the long head of the biceps tendon (LHBT). However, conventional magnetic resonance (MR) imaging (MRI) has low diagnostic accuracy for LHBT and pulley lesions. Here, we investigated the usefulness of novel biceps-radial MRI for evaluating LHBT and pulley lesions. METHODS: Biceps-radial MR images of 84 patients (84 shoulders) were prospectively analyzed. The biceps-radial MRI protocol includes sequences acquired in radial planes perpendicular to the LHBT in the shoulder joint. All patients underwent shoulder arthroscopy, and the intraoperative LHBT and pulley lesion findings were compared to the preoperative evaluations. The diagnostic accuracies of the biceps-radial MR images and conventional MR images were determined. RESULTS: A normal LHBT was observed in 30 (31.6%) patients, partial tears in 43 (52.6%), and complete tears in 11 (15.8%). Normal LHBT stability was present in 54 (61.4%) patients, subluxation in 24 (31.6%), and dislocation in 6 (7.0%). The biceps-radial MR (kappa coefficient: 0.94) and conventional MR (kappa coefficient: 0.68) images accurately identified LHBT tears. The biceps-radial MR images excellently agreed with the arthroscopic findings (kappa coefficient: 0.91), whereas the conventional MR images poorly agreed (kappa coefficient: 0.17) regarding LHBT instability. A normal medial wall of the pulley was observed in 26 (31.0%) patients, partial tears in 30 (35.7%), and complete tears in 28 (33.3%). A normal lateral wall of the pulley was observed in 30 (35.7%) patients, partial tears in 21 (25.0%), and complete tears in 33 (39.3%). The biceps-radial MR images excellently agreed with the arthroscopic findings (kappa coefficient: 0.89), whereas the conventional MR images moderately agreed (kappa coefficient: 0.50) regarding medial pulley lesions. The biceps-radial MR images excellently agreed with the arthroscopic findings (kappa coefficient: 0.95) and the conventional MR images moderately agreed (kappa coefficient: 0.56) regarding lateral pulley lesions. CONCLUSION: Biceps-radial MRI allows for tracking of the LHBT and pulley from the supraglenoid tuberosity to the bicipital groove in the glenohumeral joint and accurate evaluations of LHBT and pulley lesions.

Effect of quantitative partial valgus stress during baseball pitching on ball velocity and subjective pitch-effort.

BACKGROUND: Excessive elbow valgus stress can often cause pitching elbow injuries, and rehabilitation is usually required before an athlete can resume playing. However, there is a lack of information on the partial load rehabilitation of pitching elbow injuries caused by valgus extension overload based on elbow valgus stress. The purpose of this study was to clarify how quantitative partial elbow valgus stress while pitching affects ball velocity and subjective pitch-effort. METHODS: Forty-six male baseball pitchers participated in this study. Each player wore a wearable device on the elbow that collected their pitch parameters. Ball velocity was measured using a radar gun. Each elbow valgus stress was measured while each player was instructed to throw 5 fastballs at full effort. Then, based on the average stress of the 5 throws (100% partial valgus stress), the 75% and 50% stresses were calculated (75% and 50% partial valgus stress, respectively). Each pitcher continued to pitch until the number of pitches thrown at the targeted elbow stress reached 5. Each player was asked about their subjective pitch-effort after completing each type of partial valgus stress pitch. Outcomes were statistically evaluated using either a 1-way repeated measures analysis of variance or 2-way analysis of variance. RESULTS: The ball velocity was 72% (95% confidence interval [CI], 69%-75%) and 58% (95% CI, 55%-61%) during the 75% and 50% partial valgus stress, respectively (P < .001). Subjective pitch-effort was 41% (95% CI, 38%-44%) and 19% (95% CI, 16%-22%) while pitching at 75% and 50% partial valgus stress, respectively (P < .001). CONCLUSIONS: It may be desirable to instruct pitchers to throw at less than 20% subjective pitch-effort of the max if they want to pitch at 50% partial valgus stress. Elbow valgus stress might correlate with ball velocity at 75% partial valgus stress pitch. These results could enable clinicians and coaches to perform safer return-to-throwing programs and prevent excessive load on the elbow.

Ultrasound findings of the deltoid ligament in patients with acute ankle sprains: A retrospective review.

BACKGROUND: The deltoid ligament is a complex structure composed of multiple ligaments located on the medial side of the ankle joint that can be injured by ankle sprains. Although there have been previous reports on ultrasound imaging of the injured deltoid ligament, a systematic method for depicting each ligament component has not been established. This study aimed to clarify the ultrasound findings of the deltoid ligament in ankle sprains using a systematic scanning protocol. METHODS: We examined the tenderness of the medial ankle and evaluated the ultrasound findings of the deltoid ligament in 169 sprained ankles with no fracture, within 3 days after injury. Observation and evaluation of the six components of the deltoid ligament were performed using a systematic scanning protocol with four probe positions. RESULTS: Of the 169 ankles, 48 ankles had tenderness in the deltoid ligament. Ultrasonography confirmed deltoid ligament damage in 13 of these 48 ankles. Of the 13 ankles, 3 ankles had damages only in the superficial layer, 3 ankles only in the deep layer, and 7 ankles in both the superficial and deep layers. CONCLUSIONS: We clarified the details of the damage pattern of the deltoid ligament in acute ankle sprains. It was possible to identify the superficial and deep layers of the ligament and to observe the damage pattern of each ligament component in detail, and it appeared that ultrasonography could be used as a tool to evaluate the damage pattern of the deltoid ligament in acute ankle sprains.

Do standardization of the procedure reduce measurement variability of the sonographic anterior drawer test of the ankle?

BACKGROUND: In quantitative ankle stress sonography, different examiners use different techniques, which may cause measurement variability. This study aimed to clarify whether standardizing stress sonography techniques reduces variability in the quantitative measurement of anterior talofibular ligament length change. METHODS: Fourteen examiners with a mean ultrasound experience of 8.7 years participated in this study. Each examiner performed stress ultrasonography of the ankle using their preferred method on one patient with an intact anterior talofibular ligament (Patient 1) and on two patients with chronic ankle instability (Patient 2 and 3). Changes in the ligament length between the resting and stressed positions were determined. A consensus meeting was then conducted to standardize the sonographic technique, which was used by the examiners during a repeat stress sonography on the same patients. The variance and measured values were compared between the preferred and standardized techniques using F-tests and paired t-tests, respectively. RESULTS: At a consensus meeting, a sonographic technique in which the examiner pushed the lower leg posteriorly against the fixed foot was adopted as the standardized technique. In Patient 1, the change in the anterior talofibular ligament length was 0.4 (range, -2.3-1.3) mm and 0.6 (-0.6-1.7) mm using the preferred and standardized techniques, respectively, with no significant difference in the variance (P = 0.51) or the measured value (P = 0.52). The length changes in Patient 2 were 2.0 (0.3-4.4) mm and 1.7 (-0.9-3.8) mm using the preferred and standardized techniques, respectively. In Patient 3, the length changes were 1.4 (-2.7-7.1) mm and 0.7 (-2.0-2.3) mm. There were no significant differences between the techniques in either patient group. CONCLUSION: Variability in the quantitative measurement of ankle stress sonography was not reduced despite the standardization of the technique among examiners. Hence, comparing the measured values between different examiners should be avoided.

Force-Induced Alignment of Nanofibrillated Bacterial Cellulose for the Enhancement of Cellulose Composite Macrofibers.

Bacterial cellulose, as an important renewable bioresource, exhibits excellent mechanical properties along with intrinsic biodegradability. It is expected to replace non-degradable plastics and reduce severe environmental pollution. In this study, using dry jet-wet spinning and stretching methods, we fabricate cellulose composite macrofibers using nanofibrillated bacterial cellulose (BCNFs) which were obtained by agitated fermentation. Ionic liquid (IL) was used as a solvent to perform wet spinning. In this process, force-induced alignment of BCNFs was applied to enhance the mechanical properties of the macrofibers. The results of scanning electron microscopy revealed the well-aligned structure of BCNF along the fiber axis. The fiber prepared with an extrusion rate of 30 m min-1 and a stretching ratio of 46% exhibited a strength of 174 MPa and a Young's modulus of 13.7 GPa. In addition, we investigated the co-spinning of carboxymethyl cellulose-containing BCNF with chitosan using IL as a "container", which indicated the compatibility of BCNFs with other polysaccharides. Recycling of the ionic liquid was also verified to validate the sustainability of our strategy. This study provides a scalable method to fabricate bacterial cellulose composite fibers, which can be applied in the textile or biomaterial industries with further functionalization.

Hypoxia with or without Treadmill Exercises Affects Slow-Twitch Muscle Atrophy and Joint Destruction in a Rat Model of Rheumatoid Arthritis.

The effects of treadmill running under hypoxic conditions on joints and muscles of collagen-induced arthritis (CIA) rats were investigated. CIA rats were divided into normoxia no-exercise, hypoxia no-exercise (Hypo-no), and hypoxia exercise (Hypo-ex) groups. Changes were examined on days 2 and 44 of hypoxia with or without treadmill exercises. In the early stage of hypoxia, the expression of hypoxia-inducible factor (HIF)-1α increased in the Hypo-no and Hypo-ex groups. The expression of the egl-9 family hypoxia-inducible factor 1 (EGLN1) and vascular endothelial growth factor (VEGF) in the Hypo-ex group also increased. Under sustained hypoxia, the Hypo-no and Hypo-ex groups did not show increased expression of HIF-1α or VEGF, but p70S6K levels were elevated. Histologically, joint destruction was alleviated in the Hypo-no group, the loss of muscle weight in slow-twitch muscles was prevented, and muscle fibrosis was suppressed. In the Hypo-ex group, the preventive effect of a reduction in the slow-twitch muscle cross-sectional area was enhanced. Thus, chronic hypoxia in an animal model of rheumatoid arthritis controlled arthritis and joint destruction and prevented slow-twitch muscle atrophy and fibrosis. The combination of hypoxia with treadmill running further enhanced the preventive effects on slow-twitch muscle atrophy.

Indication for Achilles Tenotomy in Congenital Clubfoot: Effectiveness of Using the Tibio-Plantar Fascia Angle as a Radiographic Parameter.

Congenital clubfoot is one of the most common deformities in children, and currently, the Ponseti method is used worldwide because of its favorable short-term results. With the Ponseti method, the indication for Achilles tenotomy is traditionally based on only physical examination findings; however, some surgeons have also utilized plain radiographs. Because using physical examinations to determine the degree of hindfoot dorsiflexion for the indication of tenotomy can lead to underestimation. We developed and utilized the effectiveness of the tibio-plantar fascia angle (Ti-P angle) in the lateral maximum dorsiflexion view in determining the need for Achilles tenotomy. A retrospective analysis of consecutive 26 patients with congenital idiopathic clubfeet (37 feet) was performed. Whether Achilles tenotomy was indicated was determined based on physical examination for a former period (Group P). For the latter period, whether tenotomy was indicated was determined by referencing radiographs (Group X). No significant differences were found in any of the background factors or severity between Group P and Group X. Cases with larger tibiocalcaneal and Ti-P angles were more likely to require Achilles tenotomy or additional soft tissue release. An angle of more than 72° of the Ti-P angle demonstrated adequate specificity for the indication of Achilles tenotomy. The radiographic lateral tibio-plantar fascia angle is useful for deciding whether a tenotomy needs to be performed.

Trends and age- and sex-stratified analysis of hallux valgus correction surgery from 2014 to 2019: A nationwide population-based cohort study in Japan.

BACKGROUND: Epidemiological studies on hallux valgus (HV) are challenging owing to differences in sampling and diagnostic criteria across studies. This study aimed to indirectly clarify HV epidemiology using a national database. METHODS: The age- and sex-stratified annual number rate of HV correction (RHVC) per 100,000 people in Japan during 2014-2019 were examined. RESULTS: The average annual RHVC was 3.0. RHVC had unimodal (peak, 65-79 years) and bimodal (peaks, 15-19 and 70-74 years) distributions among males and females, respectively, and increased over time in males aged 50-54 and 75-79 years and females aged 80-84 years. CONCLUSIONS: RHVC increases with increasing age and occurs commonly in female teens. The recent RHVC in Japan was lower than that reported in Europe and the United States, with an increasing trend among elderly people. LEVEL OF EVIDENCE: III.

Crystal structure and substrate recognition mechanism of the prolyl endoprotease PEP from Aspergillus niger.

Proteases are enzymes that are not only essential for life but also industrially important. Understanding the substrate recognition mechanisms of proteases is important to enhance the use of proteases. The fungus Aspergillus produces a wide variety of proteases, including PEP, which is a prolyl endoprotease from A. niger. Although PEP exhibits amino acid sequence similarity to the serine peptidase family S28 proteins (PRCP and DPP7) that recognize Pro-X bonds in the terminal regions of peptides, PEP recognizes Pro-X bonds not only in peptides but also in proteins. To reveal the structural basis of the prolyl endoprotease activity of PEP, we determined the structure of PEP by X-ray crystallography at a resolution of 1.75 Å. The PEP structure shows that PEP has a wide-open catalytic pocket compared to its homologs. The characteristic catalytic pocket structure of PEP is predicted to be important for the recognition of protein substrates.

CD81 inhibition with the cytoplasmic RNA vector producing anti-CD81 antibodies suppresses arthritis in a rat CIA model.

OBJECTIVE: Cluster of differentiation 81 (CD81) is a tetraspanin membrane protein consisting of 4 transmembrane domains and 2 outer membrane loops. CD81 inhibition is a potential treatment for rheumatoid arthritis (RA). Here, we investigated the therapeutic effects of the cytoplasmic RNA vector expressing anti-CD81 antibodies (the anti-CD81 vector) on the ankle joint synovium in collagen-induced arthritis (CIA) rats. METHODS: Body weight, paw volume, and clinical scores were measured on days 0, 7, and 10 and daily thereafter. On day 28, the ankle joints of the rats were removed and stained with haematoxylin, eosin, and Safranin O. Arthritic changes such as inflammatory cell infiltration, synovial proliferation, articular cartilage destruction, and bone erosion were evaluated by histological scoring. RESULTS: Symptom onset was delayed in the right lower limbs of the rats administered the cytoplasmic RNA vector (CIA + anti-CD81) compared with that in the control group (CIA + control). The CIA + anti-CD81 rats were heavier than the CIA + control rats. The paw volume and clinical scores were significantly lower in the CIA + anti-CD81 than in the CIA + control. The histological scores indicated significantly milder manifestations of RA in the CIA + anti-CD81 than in the CIA + control. CONCLUSIONS: Administration of the cytoplasmic RNA vector expressing anti-CD81 antibodies suppressed arthritis and joint destruction in CIA rats. Our findings suggest that the cytoplasmic RNA vector can be used to treat RA.