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Much attention is being devoted to the potential of marine sulfated polysaccharides as antiviral agents in preventing COVID-19. In this study, sulfated fucoidan and crude polysaccharides, extracted from six seaweed species (Undaria pinnatifida sporophyll, Laminaria japonica, Hizikia fusiforme, Sargassum horneri, Codium fragile, Porphyra tenera) and Haliotis discus hannai (abalone viscera), were screened for their inhibitory activity against SARS-CoV-2 virus entry. Most of them showed significant antiviral activities at an IC50 of 12~289 μg/mL against SARS-CoV-2 pseudovirus in HEK293/ACE2, except for P. tenera (IC50 > 1000 μg/mL). The crude polysaccharide of S. horneri showed the strongest antiviral activity, with an IC50 of 12 μg/mL, to prevent COVID-19 entry, and abalone viscera and H. fusiforme could also inhibit SARS-CoV-2 infection with an IC50 of 33 μg/mL and 47 μg/mL, respectively. The common properties of these crude polysaccharides, which have strong antiviral activity, are high molecular weight (>800 kDa), high total carbohydrate (62.7~99.1%), high fucose content (37.3~66.2%), and highly branched polysaccharides. These results indicated that the crude polysaccharides from seaweeds and abalone viscera can effectively inhibit SARS-CoV-2 entry.

Phenolic compounds and carotenoids are potential inhibitors of cytochrome P450s. Sixteen known compounds, phenolic compounds and carotenoids from seaweed were examined for potential inhibitory capacity against CYP1A2 and CYP3A4 in silico and in vitro. Morin, quercetin, and fucoxanthin inhibited the enzyme activity of CYP1A2 and CYP3A4 in a dose-dependent manner. The IC50 values of morin, quercetin, and fucoxanthin were 41.8, 22.5, and 30.3 μM for CYP1A2 and 86.6, 16.1, and 24.4 μM for CYP3A4, respectively. Siphonaxanthin and hesperidin did not show any significant effect on CYP1A2, but they slightly inhibited CYP3A4 activity at high concentrations. In silico modeling of CYP’s binding site revealed that the potential inhibitors bound in the cavity located above the distal surface of the heme prosthetic group through the 2a or 2f channel of CYPs. This study presents an approach for quickly predicting CYP inhibitory activity and shows the potential interactions of compounds and CYPs through in silico modeling.

Category: Hindfoot Introduction/Purpose: Posterior tibial tendon’s condition has traditionally been evaluated using ultrasonography or magnetic resonance imaging, but recent advancements in radiography have increased the resolution of radiographic soft tissue images. We performed this study to examined whether the posterior tibial tendon could be screened using anteroposterior foot radiographs, based on interobserver agreement and accuracy. Methods: We retrospectively evaluated consecutive patients who underwent weight-bearing foot radiography and ultrasonography based on a suspicion of posterior tibial tendinopathy. The integrity of the posterior tibial tendon was evaluated by two orthopaedic surgeons (8 years and 3 years of experience) using foot radiographs, and scored as having normal or abnormal tendon integrity (Fig). We evaluated interobserver agreement between the two surgeons, and the ultrasonography and radiography findings were compared to evaluate diagnostic accuracy. Results: We included 21 patients with a mean age of 51.5 ± 15.7 years (5 men and 16 women). Ultrasonography revealed 4 patients with normal tendon integrity, 6 patients with tenosynovitis and no tendinopathy, 8 patients with tendinopathy and tendon continuity, and 3 patients with loss of tendon continuity. The surgeons provided consistent radiographic findings for 81.0% of the patients (17/21; kappa = 0.576, p = 0.007). Based on the ultrasonographic findings, the surgeons provided accuracies of 76.2% (16/21) and 61.9% (13/21). Conclusion: The results indicate that weight-bearing anteroposterior foot radiography can be used to evaluate posterior tibial tendon integrity, which may allow physicians to predict the prognosis of patients with PTTD, to determine the extent of surgical treatment, and to evaluate the postoperative tendon integrity.

Category: Ankle, Trauma Introduction/Purpose: Several methods like cortical screw, Kirschner (K) wire have been used for stabilizing the Lisfranc joint. We performed this study to assess whether single dorsal plating can be used as an alternative treatment method for a Lisfranc injury. Methods: Patients were followed up for more than 1 year after the initial surgery.Following open reduction of the joint with a bone reduction clamp, a single dorsal plate was used to perform Lisfranc joint fixation. The plate was fixed with 2.7-mm locking screws on the first metatarsal, second metatarsal, medial cuneiform, and intermediate cuneiform. Three weeks postoperatively, the cast was removed, and patients progressively advanced to full weight bearing while wearing a postoperative shoe. The plate was removed 3 months postoperatively. One year postoperatively, weight-bearing foot radiographs and the American Orthopedic Foot and Ankle Society (AOFAS) ankle-hindfoot scale score were obtained. Results: Eighteen patients with a Lisfranc injury who were treated with open reduction and internal fixation using a single dorsal plate were included. The average AOFAS midfoot score for pain was 35, and the total score was 80.8 (range, 67–95). Six patients (33.3%) had an excellent outcome (score =90); eight (44.4%) had a good outcome (90 > score = 75); and four (22.2%) had a fair outcome (75 > score = 50). Radiographs during the follow-up period showed no loss of reduction or arthritic change. Screw breakage occurred in 3 cases. But the injury ultimately healed anatomically. Conclusion: Single dorsal plating can be an alternative treatment method for a Lisfranc injury, as it provides a good short-term outcome without causing further joint injury.

Category: Bunion, Midfoot/Forefoot Introduction/Purpose: There is a lack of quantitative studies on the progression of juvenile hallux valgus deformity. Therefore, we performed this study to estimate an annual change of radiographic indices for juvenile hallux valgus. Methods: We reviewed medical records of consecutive patients under the age of 15 with juvenile hallux valgus who underwent weight-bearing foot radiographs more than twice, and were followed over a period of one year or more. A total of 133 feet from 69 patients were included. Hallux valgus angle, hallux interphalangeal angle, intermetatarsal angle, metatarsus adductus angle, distal metatarsal articular angle, anteroposterior talo-1st metatarsal angle, anteroposterior talo-2nd metatarsal angle, and lateral talo-1st metatarsal angle were measured and were used as a study criteria. The progression rate of hallux valgus angle was adjusted by multiple factors including the use of a linear mixed model with gender and radiographic measurements as the fixed effects and laterality and each subject as the random effect. Results: Our results demonstrate that the value of hallux valgus angle on the radiographs progressed as the patients grew older. The hallux valgus angle increased by 0.8° per year (p

Category: Ankle, Sports Introduction/Purpose: We hypothesized that the bony configuration of the ankle could also be associated with ankle stress radiographs, in addition to ligament injury of the ankle. Therefore, this study aimed to investigate the relationship between bone morphology and injured ligament on imaging studies and laxity on ankle stress radiographs in patients with lateral ankle instability. Methods: In total, 115 patients who had undergone ankle MRI, ankle radiography, and stress radiography were included. Distal tibial articular surface angle, bimalleolar tilt, medial and lateral malleolar relative length, medial malleolar slip angle, anterior inclination of the tibia, and fibular position were measured on ankle radiographs. Tibiotalar tilt angle and anterior translation of the talus were measured on ankle stress radiographs. Degree of ligament injury was evaluated on ankle MRIs. Multiple regression analysis was performed using the following independent variables: age, sex, and factors significantly associated with ankle stress view on univariate linear regression analysis. Results: Age (p = 0.041), sex (p = 0.014), degree of anterior talofibular ligament injury (p < 0.001), and bimalleolar tilt (p = 0.016) were correlated with tibiotalar tilt angle (Table). Younger patients demonstrated a larger tibiotalar tilt angle than older patients, and the angle decreased by 0.07° per year of age. Tibiotalar tilt angle in female patients was 2.2° larger than that in male patients. Fibular position and degree of posterior talofibular ligament injury were factors significantly related to anterior translation of the talus. Conclusion: Differences in patient characteristics might predispose ankle stress radiograph results. Comparison of both ankles on stress radiographs is superior to applying fixed numerical values to the injured side, in order to reduce the influence of patient factors.

Category: Basic Sciences/Biologics Introduction/Purpose: Human palatine tonsil-derived mesenchymal stem cells (T-MSCs) are known to be a new source of progenitor cells. Using waste tissue after tonsillectomy as a cell provider can be the biggest benefit of T-MSCs, compared with other stem cells. The purpose of this study was to investigate tenogenic differentiation of T-MSCs and to access the differential effects of TGF-ß3 on the tenogenesis of T-MSCs. Methods: Human tonsil was obtained after tonsillectomy.Using a cytometric analysis, we were able to find that the T-MSCs had typical mesenchymal stem cell markers: positive for CD73, CD90 and CD105, and negative for CD14, CD34 and CD45. Using a Transforming growth factor beta 3 (TGF-ß3), the expressions of tenocyte-specific genes and proteins, such as Collagen type I (COL1), Tenomodulin (TNMD), and Scleraxis (SCX), were measured by a quantitative polymerase chain reaction (PCR) assay, immunofluorescence staining, immunohistochemistry and Western blot analysis. Results: Quantitative PCR assay showed that TGF-ß3 significantly increased the expressions of tenocyte lineage marker genes, including Collagen type I (COL1), Tenomodulin (TNMD), and Scleraxis (SCX), at a 3-day treatment, compared with control. However, these increases were not found at long-term exposures (7 or 10 days), except that TNMD expression was maintained at 50 ng/ml at 7-day exposure to TGF-ß3 (Fig). Like genes, the protein expression levels of COL1, TNMD, and SCX were also induced in TGF-ß3-treated T-MSCsin 3-day treatments. Moreover, the protein levels were maintained for 10 days, as evidenced by immunofluorescence staining, immunohistochemistry and Western blot analyses. Conclusion: This study demonstrated that T-MSCs in tenogenic stimulation with TGF-ß3 have high tenogenic differentiation potential.

Category: Basic Sciences/Biologics Introduction/Purpose: Although pedobarographic measurement is increasingly used for clinical and research purposes, relatively few published studies have investigated normative data. This study examined pedobarographic findings in young healthy adults with regard to sex-related differences and correlations among measurement indices. Methods: Twenty young healthy adults (mean age 22.4 years, SD 1.2 years; 10 males and 10 females) were included. Weightbearing anteroposterior and lateral foot radiographs were taken, and dynamic pedobarographic data during treadmill walking and maximum ankle dorsiflexion were obtained. AP talo-first metatarsal angle, naviculocuboid overlap, lateral talo-first metatarsal angle, and plantar soft tissue thickness were measured on foot radiographs. Pedobarographic data including peak pressure and pressure-time integral were measured on five plantar segments: medial forefoot (MFF), lateral forefoot (LFF), medial midfoot (MMF), lateral midfoot (LMF), and heel. Results: Male and female subjects significantly differed in BMI (p

Category: Ankle Introduction/Purpose: The gastrocnemius, a biarticular muscle that crosses the knee and ankle, acts as a knee flexor as well as an ankle plantar flexor. Although simultaneous motion of the knee and ankle joints is required for many activities including standing, running, swimming, and cycling, the change in ankle motion during gait has not been described in patients with cerebral palsy who underwent distal hamstring lengthening or distal hamstring lengthening with rectus femoris transfer. Therefore, we aimed to evaluate the influence of surgery involving tendons around the knee on ankle motion during gait in cerebral palsy patients. Methods: The analysis included data regarding 55 limbs from 34 patients with spastic cerebral palsy, who were followed-up after they had undergone distal hamstring lengthening with or without additional rectus femoris transfer. Mean age of the patients at time of the knee surgery was 11.2 ± 4.7 years. Preoperative and postoperative kinematic variables that were extracted from three-dimensional gait analyses were compared to assess the change in ankle motion after surgery involving tendons around the knee. The postoperative 3D gait analysis was performed at a mean of 0.9 ± 1.3 years after the surgery. The outcome measures were relevant kinematics parameters including peak ankle dorsiflexion at initial contact, peak ankle dorsiflexion during stance, ankle peak dorsiflexion during swing, and dynamic range of motion of the ankle. A linear mixed model was constructed to estimate the changes in ankle motion after adjusting for multiple factors. Results: We estimated that peak ankle dorsiflexion at initial contact, peak ankle dorsiflexion during stance, ankle peak dorsiflexion during swing, and dynamic range of motion of the ankle decreased, respectively, by 0.4º (p=0.016), 0.6º (p