Effect of intra-articular ozone injection on serum and synovial TNF-α, TNFR I, and TNFR II contents in rats with rheumatoid arthritis / 南方医科大学学报

<p><b>OBJECTIVE</b>To observe the effects of intra-articular ozone injection at different concentrations on the contents of tumor necrosis factor-α (TNF-α), TNF receptor I (TNFR I), and TNFR II in the serum and synovium of rats with rheumatoid arthritis (RA) and explore the therapeutic mechanism of ozone in RA treatment.</p><p><b>METHODS</b>Forty-eight Wistar rats were randomized into 8 groups, including 5 ozone groups receiving intra-articular injection of 10, 20, 30, 40 or 50 µg/ml ozone, a blank control group, an oxygen group and a RA model group. All the rats, except for those in the blank control group, were subjected to hypodermic injection of bovine collagen II and complete Freunds adjuvant to induce RA. Ozone treatment was administered once weekly for 3 weeks starting at 21 days after the modeling. The swelling and thickness of the hind paws were observed, and the serum and synovial contents of TNF-α, TNFR I, and TNFR II were detected.</p><p><b>RESULTS</b>At the end of treatment, the paw thickness was reduced significantly in rats with 40 µg/ml ozone injection compared with that in the model RA group (P<0.01). The serum contents of TNF-α, TNFR I and TNFR II showed no significant difference between the RA model group, oxygen group and the ozone groups, but their synovial contents showed significant reductions in rats with 40 and 50 µg/ml ozone injection (P<0.01); the synovial TNFR I was significantly higher in 40 µg/ml ozone group than in the model group (P<0.05).</p><p><b>CONCLUSION</b>Intra-articular injection of 40 µg/ml ozone can attenuate synovitis in rats with RA, the mechanism of which may involve the inhibition of TNF-α and TNFR II activity and enhancement of TNFR I activity in the synovium.</p>

Establishment of a three-dimensional finite element model and stress analysis of the talus during normal gait / 南方医科大学学报

<p><b>OBJECTIVE</b>To develop a three-dimensional (3D) finite element model of the human ankle with fine details and analyze the stress distribution on the talus during different gait phases.</p><p><b>METHODS</b>Mimics13.0 and Geomagic10.0 software were used for geometric reconstruction of the ankle based on the 3D CT data of the foot. The model was meshed and assigned with the material properties in Hypermesh10.0 software. The model was then imported to Abaqus6.9, and the stress condition of the talus during the 3 phases (heel-strike, midstance, push-off) of normal gait was simulated to calculate the stress distribution within the bone.</p><p><b>RESULTS</b>The three-dimensional finite element model of the ankle established consisted of 21 865 nodes and 73 440 elements. The stress distribution within the bone in 3 phases of normal gait differed significantly. The peak von Mises stress on the talus dome, from the heel-strike to push-off phases, was 3.0 MPa, 4.3 MPa and 4.8 MPa, as compared to 1.3 MPa, 1.9 MPa and 2.8 MPa on the talar neck, 2.8 MPa, 3.0 MPa, and 3.4 MPa on the talonavicular joint surface, and 2.2 MPa, 1.8 MPa and 1.5 MPa on the subtalar joint, respectively.</p><p><b>CONCLUSION</b>The finite element model of the talus shows a good response against the experimental data and can be used to simulate the biomechanic experiment of the talus.</p>

Effect of ozone water on the inflammation and repair in infected wounds / 南方医科大学学报

<p><b>OBJECTIVE</b>To study the effect of ozone water in promoting the healing of infected wounds.</p><p><b>METHODS</b>Fifty Wistar rats were randomly divided into 5 groups, namely chlorhexidine treatment group, 5, 10, and 20 mg/L ozone water treatment groups, and the control group without any treatment. Infected wounds were induced on the back of the rats, and at 48 h of infection, chlorhexidine or ozone water was applied once daily for 9 days. Before and at days 3, 6, and 9 of the treatment, the wound changes were observed. The WBC in the tail venous blood was detected and the incised skin and muscular tissues were pathologically examined. RESULTS AMD CONCLUSION: Ozone water showed better effects in promoting the healing of the infected wound, especially at higher doses of 10 and 20 mg/L.</p>