Effect of CO2 and H2 gas mixture in cold water immersion on recovery after eccentric loading.

Background: The findings of previous studies support the efficacy of cold water immersion (CWI) with carbon dioxide (CO2) in enhancing muscle blood flow and maintaining aerobic performance efficiency. We hypothesize that the addition of hydrogen gas (H2), known for its antioxidant properties and role in inflammation regulation, to C-CWI can enhance recovery after eccentric exercise. Subjects: and Methods: Thirty-four healthy subjects performed a knee-extensor eccentric exercise. They were randomly allocated into four groups: control, CWI, CO2-rich CWI (C-CWI), and CO2 + H2 gas mixture CWI (CH-CWI). In the three CWI groups, all subjects were immersed in the appropriate bath at 20 °C for 20 min immediately after 60 repetitions of eccentric exercise. Before exercise and after 48 h of recovery, the subjects' maximal voluntary isometric contraction torque (MVC-ISO), maximal voluntary concentric (MVC-CON) contraction torque, countermovement jump (CMJ) height, knee flexion range of motion (ROM), muscle soreness, and muscle thickness were measured. Results: In the CH-CWI group only, the MVC-ISO, CMJ height, and ROM did not decrease significantly post-exercise, whereas all of these decreased in the other three groups. Muscle soreness at palpation, contraction, and stretching significantly increased post-exercise in all groups. Echo intensity and tissue hardness did not increase significantly in the CH-CWI group. Conclusions: CH-CWI stimulated recovery from impairments in MVC-ISO torque, CMJ height, knee-flexion ROM, tissue hardness, and echo intensity. These findings indicate that CH-CWI can promote recovery after eccentric exercise.

Prevalence of posterior elbow problems in Japanese high school baseball players.

BACKGROUND: Various posterior elbow problems cause posterior elbow pain among baseball players. We aimed to determine the prevalence and diagnoses associated with posterior elbow problems and post-treatment recovery time for returning to sports in Japanese high school baseball players when treated in the off-season. METHODS: A total of 576 Japanese high school baseball players who participated in baseball skill training camp during the off-season were enrolled in the study. The elbow of each player's throwing arm was assessed by use of a questionnaire and physical examination. Players with abnormal results were advised to visit the hospital. Players who visited the hospital were initially treated conservatively and underwent surgery if necessary. Retrospectively, players with positive physical examination results associated with posterior elbow pain, defined as olecranon tenderness and/or a positive elbow extension impingement test, were selected. Information about their position, elbow pain, physical examination results, diagnosis, treatment, and recovery time before returning to playing sports was assessed. RESULTS: Olecranon tenderness and/or positive elbow extension impingement test results were found in 76 players (13.2%). Of these, 33 agreed to visit the hospital for further diagnostic imaging and 25 players (75.8%) were diagnosed with posteromedial elbow impingement. By the next spring, 87.9% of players returned to sport, and 100% of players returned to sport before the next summer. The average recovery period was 77 ± 47 days. CONCLUSION: Physical examinations related to posterior elbow injuries were positive in 13.2% of high school baseball players. The most common diagnosis for posterior elbow pain was posteromedial elbow impingement. All players returned to competitive sports activity levels within 77 ± 47 days.

The effect of electroacupuncture on osteotomy gap healing in a rat fibula model.

OBJECTIVE: To examine the effect of electroacupuncture (EA) on osteotomy gap healing in a rat fibula model. METHODS: A total of 40 12-week-old male Wistar rats underwent unilateral open osteotomy of the fibula to create a 2 mm gap. The rats were randomly assigned to an EA group (n=20) and a control group (n=20). In the EA group, a cathodal electrode was connected to an acupuncture needle percutaneously at the surgery site, while another acupuncture needle inserted 15 mm proximal to the surgery site was used as an anodal electrode. EA was performed 5 days a week for 6 weeks. The control group received no treatment. Some rats were killed at 3 days and 1 week after surgery and the cut end of the distal part of the fibula was surgically removed and histologically assessed. Haematoxylin and eosin (H&E) staining was used to measure total cell count and immunohistochemical staining to assess the increase in the bone morphogenetic protein 2 (BMP-2)-positive cells. The healing process was also assessed weekly after surgery via x-ray examinations. RESULTS: At each time point, total cell count showed a marked increase in the EA group (p<0.05), while BMP-2 expression showed a tendency to increase in the EA group. Radiological examination showed a marked reduction in the distance between the cut ends of the fibula in the EA group. CONCLUSIONS: There was a marked increase in cell count and expression of growth factor in the EA group. These results indicate direct current EA could be useful for promoting bone healing.

Mucin from rheumatoid arthritis synovial fluid enhances interleukin-6 production by human peripheral blood mononuclear cells.

The carbohydrate chains represented by mucins (MUCs) are expressed by a variety of normal and malignant secretory epithelial cells and induce a variety of immunoreactions. To find new mucins related to the pathogenesis of rheumatoid arthritis (RA), we examined high-molecular-weight molecules inducing cytokines on human peripheral blood mononuclear cells (PBMCs) in synovial fluid from affected joints. We found a high-molecular-weight substance that induces interleukin 6 production on PBMCs in RA synovial fluid on gel filtration. MUC-1 was present in the resulting fractions, although they had been purified by CsCl density gradient centrifugation. We also found that MUC-1 was expressed on synovial cells and infiltrating inflammatory mononuclear cells on the sublining layer and lymphoid follicles in RA synovial tissues. CD68-positive superficial synovial cells colocalized with MUC-1 and CD68-positive macrophages were in contact with MUC-1-positive mononuclear cells. These findings imply that mucins, including MUC-1, may be related to immunoinflammatory reactions in the pathogenesis of RA.

Effect of electroacupuncture on the healing process of tibia fracture in a rat model: a randomised controlled trial.

BACKGROUND: Electrical stimulation is used to promote bone reunion, and is most effective when applied directly to the fracture site. OBJECTIVE: To examine the effects of electroacupuncture (EA) on the healing process of tibia fracture in a rat model. METHODS: Thirty 12-week-old male Wistar rats underwent unilateral open osteotomies of the tibiae. The rats were then assigned randomly to three groups: EA group (n=10), sham group (n=10) and control group (n=10). In the EA group, a cathodal electrode was connected to an acupuncture needle percutaneously penetrated directly at the surgery site, while an acupuncture needle inserted at 15 mm proximal to the surgery site was used as an anodal electrode. EA (50 Hz, 20 µA, 20 min) was performed daily for 3 weeks. In the sham group the acupuncture needles were inserted at the same sites but no electrical stimulation was given and in the control group, no treatment was given. The response was evaluated at 1, 3, 4 and 6 weeks after surgery by radiographic, macroscopic and mechanical examinations. RESULTS: The EA group showed accelerated bone healing (EA group 29.92+/-4.55 mm², sham group 26.46+/-5.21 mm², control group 26.19+/-2.81 mm², p<0.05 at 3 weeks) and accretion of the callus (radiographic evaluation: EA group 35.66+/-4.37 mm², sham group 32.60+/-5.73 mm², control group 29.72+/-6.39 mm², p<0.05 at 6 weeks) compared with the other groups. Mechanical testing also showed an excellent result (EA group 16.54+/-9.92 N, sham group 7.13+/-3.57 N, control group 6.67+/-3.12 N, p<0.05) at 6 weeks in the EA group compared with the other groups. There was no difference between the sham and control groups in any evaluation. CONCLUSION: The use of EA enhanced callus development and bone mineralisation during the bone healing process.

Hyperthermia for the treatment of articular cartilage with osteoarthritis.

Osteoarthritis (OA) is one of the most frequent musculoskeletal disorders in the elderly population. OA is characterised by a gradual loss of extracellular matrix in the articular cartilage of joints. OA can only be managed by artificial joint replacement when joint destruction becomes severe. Therefore, it is preferable to administer conservative therapy that is easy, simple and effective in inhibiting OA progression at the early stage. Heat shock protein 70 (Hsp70) has a protective effect on the cartilage and inhibits the apoptosis of chondrocytes. Heat stimulation by microwave to the joints can increase Hsp70 expression in chondrocytes, and at the same time, Hsp70 expression partially enhances matrix metabolism of the cartilage. These findings suggest that hyperthermia can be positively applied to the treatment of OA. Hyperthermia is therefore expected to be an inexpensive and less-invasive conservative therapy for OA.

Low-energy laser irradiation promotes synovial fibroblast proliferation by modulating p15 subcellular localization.

BACKGROUND AND OBJECTIVE: Low-energy laser irradiation (low-level laser therapy) (LELI/LLLT/photobiomodulation) has been found to modulate various biological effects, especially those involved in promoting cell proliferation. Synovial fibroblasts are important in maintaining the homeostasis of articular joints and have strong chondrogenetic capacity. Here, we investigated the effect and molecular basis of LELI on synovial fibroblast proliferation. STUDY DESIGN/MATERIALS AND METHODS: HIG-82 rabbit synovial fibroblasts were cultured, and laser irradiation (660 nm) was applied at the power density of 40 mW/cm(2) for 2 minutes, corresponding to laser fluence of 4.8 J/cm(2). The effect of LELI on cell proliferation, cell cycle progression, and expression of cyclin-dependent kinase inhibitors (CKIs) were investigated. We also examined whether the effects of LELI on HIG-82 cell proliferation were affected by cAMP content, which is known to influence the cell cycle via inducing CKIs. RESULTS: LELI promoted HIG-82 synovial fibroblast proliferation and induced cytoplasmic localization of cyclin-dependent kinase inhibitor p15 (INK4B/CDKN2B). Moreover, the proliferation of HIG-82 synovial fibroblasts was reduced by cAMP, while cAMP inhibitor, SQ22536, induced p15 cytoplasmic localization and as a result, elevated synovial fibroblast proliferation was observed. In addition, the promotive effect of LELI-induced HIG-82 synovial fibroblast proliferation was abolished by cAMP treatment. Our findings suggest that cAMP may be involved in the effect of LELI on synovial fibroblast proliferation. CONCLUSION: We revealed the effect and molecular link involved in synovial fibroblast proliferation induced by 660-nm LELI. Our study provides new insights into the mechanisms by which LELI has biological effects on synovial fibroblast proliferation. These insights may contribute to further investigation on biological effects and application of LELI in regenerative medicine.

siRNA targeting PLK-1 induces apoptosis of synoviocytes in rheumatoid arthritis.

Polo-like kinase-1 (PLK-1) is a member of the PLK family and participates in the control of cell mitosis. Here, we show that immunoreactive PLK-1 is strongly expressed in synoviocytes and some infiltrative mononuclear cells in synovial tissues from patients with rheumatoid arthritis (RA), while patients with osteoarthritis and injury show little or no expression of PLK-1 in synovial tissues. Western blot analysis shows that PLK is expressed and its expression is enhanced by IL-1beta in RA synoviocytes. IL-1beta also enhanced the cell growth of RA synoviocytes. Moreover, siRNA targeted against PLK-1 significantly decreases the expression of PLK-1 of RA synoviocytes stimulated by IL-1beta and suppresses the proliferation of these synoviocytes through apoptosis. These findings suggest that PLK-1 plays a critical role in the proliferation of RA synoviocytes leading to bone destruction, and siRNA against PLK-1 is potentially useful for the treatment of RA.

A critical role for allograft inflammatory factor-1 in the pathogenesis of rheumatoid arthritis.

Rheumatoid arthritis (RA) is characterized by massive synovial proliferation, angiogenesis, subintimal infiltration of inflammatory cells and the production of cytokines such as TNF-alpha and IL-6. Allograft inflammatory factor-1 (AIF-1) has been identified in chronic rejection of rat cardiac allografts as well as tissue inflammation in various autoimmune diseases. AIF-1 is thought to play an important role in chronic immune inflammatory processes, especially those involving macrophages. In the current work, we examined the expression of AIF-1 in synovial tissues and measured AIF-1 in synovial fluid (SF) derived from patients with either RA or osteoarthritis (OA). We also examined the proliferation of synovial cells and induction of IL-6 following AIF-1 stimulation. Immunohistochemical staining showed that AIF-1 was strongly expressed in infiltrating mononuclear cells and synovial fibroblasts in RA compared with OA. Western blot analysis and semiquantitative RT-PCR analysis demonstrated that synovial expression of AIF-1 in RA was significantly greater than the expression in OA. AIF-1 induced the proliferation of cultured synovial cells in a dose-dependent manner and increased the IL-6 production of synovial fibroblasts and PBMC. The levels of AIF-1 protein were higher in synovial fluid from patients with RA compared with patients with OA (p < 0.05). Furthermore, the concentration of AIF-1 significantly correlated with the IL-6 concentration (r = 0.618, p < 0.01). These findings suggest that AIF-1 is closely associated with the pathogenesis of RA and is a novel member of the cytokine network involved in the immunological processes underlying RA.

Utility of grommets for implant arthroplasty of the great toe in a patient with rheumatoid arthritis: a case report.

We report a case of rheumatoid arthritis treated by bilateral flexible hinge toe implant arthroplasty, using grommets only on one side, which resulted in bilateral fractures requiring removal of the implants 6.5 years after the surgery. Both implants were completely fractured at the bottom of the distal stems. Macroscopically, synovitis was present around both fractured stems, although the severity of synovitis and fragmentation of the fractured implant was relatively mild on the right side in which grommets were used. The shape of the body of the fractured implant was relatively preserved on the right side in which grommets were used. There was no damage or fracture of the grommets. The grommet might have acted to prevent pressures and scratches that would cause synovitis and deformity of the body of the implant, but might not completely prevent fractures of implants.