Masaya Tsujii

The rotator cuff (RC) is frequently torn at the enthesis composed of fibrocartilage. We aimed to histopathologically evaluate lining layers and assess the distribution of a disintegrin and metalloproteinase with thrombospondin motifs (ADAMTS)4, ADAMTS5, and microRNA (miR)-140s in the synovia of patients with RC tears. We recruited 51 patients who underwent arthroscopic surgical treatment for full-thickness rotator cuff tears, including 26 patients with < 3 cm tear size (group N) and 25 patients with ≥ 3 cm tear size (group W). Biopsied synovia were analyzed using histological and immunohistological techniques for the presence ADAMTS4 and ADAMTS5. The layers of the synovial lining were morphologically classified into 3 grades according to the synovitis score and staining levels of ADAMTSs. The glenohumeral synovia from 8 patients with recurrent shoulder dislocation (group C) were used as controls. Furthermore, in situ hybridization was performed to evaluate the presence of miR-140s in patients with massive tears and recurrent shoulder dislocation. The staining levels were evaluated and analyzed based on comparison between patient groups and correlation between ADAMTS5 and miR-140s. Histological analysis revealed significant differences between groups W and C. ADAMTS5 and ADAMTS4 were strongly expressed in the synovial lining of patients in group W, and this expression was significantly higher than that in groups C and N. In addition, expression of ADAMTS5 was inversely correlated with that of miR-140-3p. This study showed that synovia from group W had a significantly higher rate of severely thickened areas with strong expression of both aggrecanases. Furthermore, the area with weak expression of miR-140-3p showed strong ADAMTS5 expression.

Cachexic condition due to malignant tumors has been a challenging problem. The aim of this study is to analyze effects of febuxostat on both in vitro and in vivo models of the wasting of skeletal muscles, due to LM8 osteosarcoma cells. C2C12 myotubes were incubated in the conditioned medium of LM8. Febuxostat was added at a concentration of 3 µM and 30 µM, and ROS, diameter of myotubes, and expression of atrogin-1 were analyzed. Furthermore, an in vivo study was performed by subcutaneous injection of LM8 on C3H mice. Febuxostat was administered in the drinking water at 5 µg/ml, and 25 µg/ml. In addition, tumor-bearing mice without febuxostat (group TB) and control mice (group C) were established. At 4 weeks, body weight, wet weights of the gastrocnemius muscles, XO activity, 8-OHdG, and expression of TNF-α and IL-6 were evaluated. ROS generation, atrophy of myotubes, and upregulation of atrogin-1 were clearly observed in C2C12 myotubes following incubation in the conditioned medium. These pathological conditions were significantly inhibited by febuxostat administration. Furthermore, mice in group TB showed significant loss of body weight and muscle weight in which XO activity, 8-OHdG, and expression of IL-6 were significantly increased compared to those in group C. Febuxostat administration not only significantly improved the body weight and muscleweight, but also reduced markers of oxidative stress and pro-inflammatory cytokines. Febuxostat did not show anti-tumor effects. Febuxostat, which is clinically used for treatment of hyperuricemia, is effective against the wasting of the skeletal muscles induced by LM8 osteosarcoma cells.

Introduction/Aims: Obesity is a factor contributing to suboptimal improvement of motor function in peripheral nerve disorders. In this study we aimed to evaluate the skeletal muscles during denervation and reinnervation after nerve crush injury in leptin‐deficient (ob/ob) mice.Methods: Experiments were performed on the skeletal muscles of the hindlimbs in 20 male ob/ob mice and controls. Characteristics of the gastrocnemius muscles were evaluated by histological analysis, immunohistological analysis, and Sircol‐collagen assay after measurement of body weight and wet weight of the skeletal muscles, and by walking track analysis. The sciatic nerve was denervated by crushing with smooth forceps and reinnervation was evaluated.Results: Gastrocnemius wet weight was significantly lower in the ob/ob mice than in the control mice. A smaller cross‐sectional area of type II fibers and increase of type I fiber grouping of the skeletal muscles was demonstrated in the ob/ob mice. After nerve injury, motor function recovery was equal between the groups but the cross‐sectional area of type II fibers was significantly smaller in the ob/ob mice than in control mice at 4 weeks. The denervated muscles showed an increase in collagen deposition in the interstitial space; predominant in the ob/ob mice after nerve injury.Discussion: The results of this study suggest that fibrosis in the skeletal muscle of obese patients after nerve injury is prominent, which may impair improvement of muscle function after treatment of peripheral nerve disorders.

Background: Obesity is a factor for insufficient improvement of motor function for peripheral nerve disorders. The aims of this study were to evaluate the skeletal muscles during denervation and re-innervation following nerve crush injury in ob/ob mice. Methods: Experiments were performed on the skeletal muscles of the hindlimbs in 20 male leptin-deficient (ob/ob) mice and control mice. Firstly, the characteristics of the gastrocnemius muscles in the mice were evaluated by histological analysis, immunohistological analysis, and Sircol-collagen assay after measurement of body weight and wet weight of the skeletal muscles and by walking tracking analysis. In the histological analysis, nicotinamide adenine dinucleotide tetrazolium reductase (NADH-TR) staining, oil red O staining, and Picro-sirius red staining were performed to assess the type of myofibers, lipid accumulation, and collagen deposition, respectively. Then, the models for denervation and re-innervation were made by crushing the sciatic nerves with smooth forceps. The same assessments were performed on the skeletal muscles of nerve crush models.Results: The wet weight of the gastrocnemius muscles was significantly less in the ob/ob mice than the control mice, whereas body weight was significantly more. Histological analyses demonstrated a smaller cross-sectional area of type II fibers and increase of type I fiber grouping of the skeletal muscles in the ob/ob mice. In addition, there was excessive deposition of lipids and collagens between the myofibers. Following the nerve injury, the recovery of motor function was equal between both groups, while the cross-sectional area of type II fibers was significantly smaller in the ob/ob mice than the control mice at 4 weeks. Furthermore, the denervated muscles showed an increase in collagen deposition to the area of intermyofibers, which were predominant in the ob/ob mice after the nerve injury.Conclusions: The present study showed an increase of collagen deposition, delayed recovery of type II myofibers, and type I fiber grouping during denervation and re-innervation in the skeletal muscles of ob/ob mice. We suggest through these findings that the reduction of contractile force could be one of causes of insufficient improvement in peripheral nerve disorders of obese individuals.

Femoral shaft nonunion after the intramedullary nailing has been successfully treated with advances in surgical technique. Nonetheless, the techniques cause morbidity to periosteum at the fracture site. We report the case of a 67-year-old man who underwent endoscopic surgery for refractory nonunion following the fracture of the distal femoral shaft, despite two fixations using an interlocking nail. In addition, the patient had uncontrolled diabetic mellitus. Endoscopy allowed us to acquire a clear view of the nonunion site, in which the resection of scar tissues and the packing of the cancellous bone were performed. At the final follow-up, bone healing was observed, and the patient was able to return to normal daily and social activity.

Background To analyze the effects of the administration of febuxostat, a selective xanthine oxidase (XO) inhibitor, on both in vitro and in vivo models of the waste of skeletal muscles, due to LM8 osteosarcoma cells. Methods C2C12 myotubes were incubated in the conditioned medium of LM8 osteosarcoma cells. At the same time, febuxostat was added at a concentration of 3 µM and 30 µM, and reactive oxygen species(ROS) was measured using 2’,7’-dichlorofluorescein diacetate (DCF-DA) at 2 h and 24 h after exposure. Furthermore, an in vivo study was performed on male C3H mice (5 weeks old) that were subcutaneously injected with LM8 osteosarcoma cells on their backs. Febuxostat was administrated in the drinking water at a concentration of 5 µg/ml (group F5), and 25 µg/ml (group F25). In addition, tumor-bearing mice without febuxostat (group TB) and control mice (group C) were established. At 4 weeks after the inoculation of tumor cells, body weight, wet weights of the gastrocnemius muscles, XO activity, 8-hydroxy-2’-deoxyguanosine(8-OHdG), and expression of TNF-α and IL-6 were evaluated and compared among the 4 groups. Results ROS generation was clearly observed in C2C12 myotubes following incubation in the conditioned medium of LM8 osteosarcoma cells. ROS generation was significantly inhibited by febuxostat administration. Furthermore, LM8-bearing mice showed significant loss of body weight and wet weight of the gastrocnemius muscles, in which XO activity, 8-OHdG, and expression of IL-6 were significantly increased compared to those in mice without injections of the tumor cells. Further, febuxostat administration not only significantly improved the body weight and wet weight of the skeletal muscles, but also reduced markers of oxidative stress and expression of pro-inflammatory cytokines. Febuxostat did not show anti-tumor effects, including inhibition of lung metastasis and improved overall survival. Conclusion Febuxostat, which is clinically used for treatment of hyperuricemia, is effective against the waste of the skeletal muscles induced by LM8 osteosarcoma cells.

Background: The aims of this study were to analyze the effects of the administration of edaravone on C2C12 myoblasts exposed to oxidative stress; to evaluate the skeletal muscles in ob/ob mice; and to analyze the effect of the administration of edaravone in the regeneration of skeletal muscle after ischemic injury. Methods: In C2C12 myoblasts, oxidative stress was induced by the exposure to 250 μM H₂O₂ for 4 h with or without pretreatment of 100 μM edaravone. Thereafter, the viability and expression of TNF-α were analyzed by MTS assay and PCR, respectively. Furthermore, an in vivo study was performed on male C57/BL6-ob/ob mice (10 weeks old) and the respective control mice. The skeletal muscles of tibialis anterior and gastrocnemius were excised for histological analysis and TBARS assay after the measurement of blood flow. In addition, the regeneration of the skeletal muscles was analyzed for the expression of MyoD 7 days after the ligation of the right femoral artery. Results: Edaravone significantly inhibited the reduction of the viability as well as upregulation of TNF-α expression by treatment with H₂O₂. In ob/ob mice, wet weight of muscles was significantly lower than that in control mice. In histology, ob/ob mice had significantly less multi-angle shaped myofibers and a significantly high level of MDA. Furthermore, MyoD expression was lower in ob/ob mice than in control mice after the ischemic injury, while edaravone (3 mg/kg) increasingly enhanced MyoD expression. Conclusion: Edaravone attenuated the oxidative stress on C2C12 myoblasts, and was effective to regeneration of skeletal muscles after ischemia in ob/ob mice.

Arthroscopic surgery is a standard technique for removal of loose bodies in large joints. By contrast, there were a few reports of arthroscopic surgery for loose bodies in small joints. We herein report a case of a 70-year-old woman with an inextensible metacarpophalangeal joint in the right middle finger due to an intra-articular loose body that developed after osteoarthritis. Surgery proceeded under vertical traction using traction tower. Two portals were developed at dorsal aspect on the metacarpophalangeal joints. The loose body was removed under arthroscopy with a small incision of both skin and sagittal band, thereby resolving clinical symptoms, including pain and limitations to metacarpophalangeal joint motion.

Purpose: The purpose of this study was to evaluate local and systemic pathology in a murine model of ischemia–reperfusion (I/R) injury induced by long-term application of a tourniquet on the hind limbs and to assess the protective effects of edaravone, a potent systemic scavenger of free radicals, using this model. Methods: Sixty C57BL6 mice were divided in two groups, with one group receiving a 3 mg/kg intraperitoneal injection of edaravone and the other group receiving an identical amount of saline 30 min before ischemia under deep anesthesia. The left thigh of each animal was constricted for 4 h with a 4.5-oz. orthodontic rubber band to induce ischemia; 4 h was the critical duration for skeletal muscles. After ischemia, specimens of skeletal muscles, both kidneys, and plasma were collected at 0, 2, 12, 24, 48, and 72 h. Injury to the skeletal muscles and vacuolar degeneration of the kidneys were histologically assessed. Additionally, apoptosis of skeletal muscle cells was assessed by analysis of caspase 3/7 activity and TUNEL staining. Plasma tumor necrosis factor (TNF)-α levels were measured using an enzyme-linked immunosorbent assay kit. Results: Skeletal muscles exhibited prominent injury of myofibers at 12 h after I/R injury, with clear upregulation of plasma TNF-α expression and histologic evidence of tubular dysfunction of the kidneys. Plasma TNF-α levels declined and histologic renal damage was ameliorated in edaravone-treated mice, but treatment did not protect skeletal muscle following ischemia for 4 h. Nonetheless, compared with group S, expression of the apoptosis marker caspase 3/7 was significantly inhibited in the skeletal hind limb muscles of Ed-group mice affected by reperfusion injury following ischemia for 4 h. Conclusion: The present study demonstrated that edaravone is a potentially useful drug for systemic or local treatment of reperfusion injury resulting from long-term ischemia.