Additional comments on extracellular vesicles derived from mesenchymal stem cells mediate extracellular matrix remodeling in osteoarthritis.

Recently, we read an article published by the Yang et al. The results of this study indicated that engineered exosomes loaded with microRNA-29a (miR-29a) alleviate knee inflammation and maintain extracellular matrix stability in Sprague Dawley rats. The study's results provide useful information for treating knee osteoarthritis (KOA). This letter, shares our perspectives on treating KOA using engineered exosomes for miR-29a.

Conservative treatment of congenital radial head subluxation and non-traumatic elbow locking: A case report.

Congenital radial head subluxation is relatively rare and may be overlooked due to mild symptoms. The diagnosis mainly relies on imaging and history. Observation is an option for those with insignificant symptoms, while surgical intervention, such as ulnar osteotomy or arthroscopy, is often required when dysfunction exists. A 30-year-old man was admitted with congenital radial head dislocation, which was treated with manipulative repositioning. During follow-up, the patient regained the original mobility of the elbow joint and had no recurrence of dislocation. In conclusion, in adults with congenital dislocation of the radial head, we recommend conservative treatment as a first step.

One-dimensional TeSe nano-heterojunction: formation, calculations, carrier dynamics, and application in broad-spectrum photodetectors.

Seawater contains many electrolytes, is abundant in nature, environmentally friendly, and chemically stable, and exhibits substantial potential for replacement of traditional inorganic electrolytes in photoelectrochemical-type photodetectors (PDs). Herein, one-dimensional semiconductor TeSe nanorods (NRs) with core-shell nanostructures were reported, and their morphology, optical behavior, electronic structure, and photoinduced carrier dynamics were systematically investigated. As photosensitizers, the as-resultant TeSe NRs were assembled into PDs, and the influence of the bias potential, light wavelength and intensity, and the concentration of seawater on the photo-response of TeSe NR-based PDs was evaluated. These PDs exhibited favorable photo-response performance upon illumination with light in the ultraviolet-visible-near-infrared (UV-Vis-NIR) range and even simulated sunlight. Moreover, the TeSe NR-based PDs also exhibited a long duration and cycling stability of its on-off switching and might be useful in marine monitoring.

Total knee arthroplasty in Ranawat II valgus deformity with enlarged femoral valgus cut angle: A new technique to achieve balanced gap.

BACKGROUND: Nearly 10% of patients undergoing primary total knee arthroplasty (TKA) have valgus deformity (VD) of the knee. For severe VD of the knee, a more lateral structural release is needed to achieve balance between medial and lateral space and neutral femorotibial mechanical axis (FTMA), which is challenging and technical. AIM: To introduce a new surgical technique of resection, soft tissue release, and FTMA for Ranawat type-II VD with a 5-year follow-up. METHODS: A retrospective study was conducted on patients who underwent TKA from December 2011 to December 2014. Hip-knee-ankle (HKA), range of motion (ROM), Oxford knee score (OKS), and knee society score (KSS) were used to assess the joint activity of patients in the new theory TKA group (NT-TKA) and were compared with those of the conventional TKA group (C-TKA). RESULTS: A total of 103 people (103 knees) were included in this study, including 42 patients with an average follow-up period of 83 mo in the C-TKA group and 61 patients with an average follow-up period of 76 mo in the NT-TKA group. Six patients had constrained prosthesis, one had common peroneal nerve injury, and two had joint instability in the C-TKA group, but none of these occurred in the NT-TKA group. There were significant statistical differences in constrained prosthesis usage and complications between the groups (P = 0.002 and P = 0.034, respectively). The KSS at 1 mo post-operation for the C-TKA and NT-TKA groups were 11.2 ± 3.8 and 13.3 ± 2.9, respectively, with a significant difference (P = 0.007). However, the data of HKA, ROM, OKS KSS, and prosthesis survival rate were insignificant (P > 0.05) in both the preoperative and follow-up periods. CONCLUSION: Adopting 5°-7° valgus cut angle for VD and sacrificing 2° neutral FTMA for severe VD which cannot be completely corrected during TKA can reduce the need for soft tissue release, maintain early joint stability, reduce the use of constrained prostheses, and minimize postoperative complications.

Bilateral synchronous total hip arthroplasty for end-stage arthropathy in hemophilia A patients: A retrospective study.

Total hip arthroplasty (THA) has been an effective tool of advanced hemophiliac hip arthritis. There are only limited data of bilateral synchronous THA for end-stage arthropathy in hemophilia A patients. The aim of this retrospective study was to analyze clinical outcome and complication rate of bilateral THA for hemophilia A patients with end-stage arthropathy of hip and review the operative strategy. From August 2012 to July 2016, 48 hips of 24 patients with hemophilia A patients underwent THA by a single experienced chief orthopedic surgeon. Clinical and radiological evaluations were included of operation time, blood loss, the quantity of blood transfusion, clotting factor consumption, duration of hospitalization, modified Harris hip score, complication rate, and radiographic assessment. All the 24 patients successfully completed the operation, followed up for 5 to 8 years, and the mean time was 6.5 years. The average operation time was 140 minutes (range, 120-180 minutes). The average total blood loss was 225 mL (range, 150-400 mL). The mean red blood cell transfusion amount was 2.4 U (range, 0-6 U). the mean hospitalization time was 24 days (range, 16-46 days). The mean amount of clotting factor VIII used in the perioperative period for management of hemophilia A was 30,600 U (range, 18,000-52,000 U). Average modified Harris hip score increased from 46.6 (range 28-70) points preoperatively to 90.2 (range 75-98) points at final follow-up, complications were few. With excellent operative techniques and hematological management, bilateral synchronous THA for end-stage arthropathy in hemophilia A patients can provide satisfactory outcomes.

New tirucallane-type triterpenoids from the resin of Boswellia carteriiand their NO inhibitory activities.

Six new tirucallane-type triterpenoids (1-6), along with ten known triterpenoids, were isolated from methylene chloride extract of the resin of Boswellia carterii Birdw. By the application of the comprehensive spectroscopic data, the structures of the compounds were clarified. The experimental electronic circular dichroism spectra were compared with those calculated, which allowed to assign the absolute configurations. Compounds 5 and 6 possesed a 2, 3-seco tirucallane-type triterpenoid skeleton, which were first reported. Their inhibitory activity against NO formation in LPS-activated BV-2 cells were evaluated. Compound 9 showed appreciable inhibitory effect, with an IC50 value of 7.58 ± 0.87 µmol·L-1.

Concealed mesenteric ischemia after total knee arthroplasty: A case report.

BACKGROUND: In critical care medicine, mesenteric ischemia (MI) is a life-threatening disease that can be present in both critically ill patients and those undergoing major surgery. For the first time, we report a case of concealed MI with a long course after knee arthroplasty. CASE SUMMARY: A male patient underwent left total knee arthroplasty for gouty arthritis and developed a persistent fever and persistently high levels of serum infection markers after surgery. He was considered to have a periprosthetic site infection and treated with antibiotics and colchicine, periprosthetic debridement was performed, and the spacer was replaced, but no improvement was seen. At 54 d after arthroplasty, the patient developed gastrointestinal symptoms of nausea and vomiting, abdominal distention, and subsequently, cloudiness of consciousness, and hypotensive shock. Finally, the patient was diagnosed with ascending colonic mesentery ischemia with necrosis after laparotomy, which improved after right hemicolectomy. CONCLUSION: Concealed MI without gastrointestinal symptoms after major surgery is rare and easily misdiagnosed. Orthopedic surgeons need to be aware of this complication.

Subchondral bone as a novel target for regenerative therapy of osteochondritis dissecans: A case report.

BACKGROUND: Osteochondritis dissecans (OCD) is a rare disease of unclear cause characterized by subchondral bone damage and overlying cartilage defects. The current report presents the results of subchondral bone as a novel target for implantation of peripheral blood stem cells (PBSCs) in the treatment of OCD. CASE SUMMARY: A 16-year-old patient diagnosed with OCD underwent subchondral bone implantation of PBSCs. Four months later, the patient's visual analog scale scores, Western Ontario and McMaster University osteoarthritis index, and whole-organ magnetic resonance imaging score improved significantly, and regeneration of cartilage and subchondral bone was observed on magnetic resonance imaging. CONCLUSION: This is the first case of OCD treated with subchondral bone as an implantation target of PBSCs, which highlights the importance of subchondral bone for cartilage repair. This treatment could be a potential option for articular cartilage and subchondral bone recovery in OCD.

New tirucallane-type triterpenoids from the resin of Boswellia carteriiand their NO inhibitory activities / 中国天然药物

Six new tirucallane-type triterpenoids (1-6), along with ten known triterpenoids, were isolated from methylene chloride extract of the resin of Boswellia carterii Birdw. By the application of the comprehensive spectroscopic data, the structures of the compounds were clarified. The experimental electronic circular dichroism spectra were compared with those calculated, which allowed to assign the absolute configurations. Compounds 5 and 6 possesed a 2, 3-seco tirucallane-type triterpenoid skeleton, which were first reported. Their inhibitory activity against NO formation in LPS-activated BV-2 cells were evaluated. Compound 9 showed appreciable inhibitory effect, with an IC

Promotion of Bone Formation by Red Yeast Rice in Experimental Animals: A Systematic Review and Meta-Analysis.

OBJECTIVE: To systematically evaluate the effects of red yeast rice (RYR) and its extract on bone formation in experimental animals and to provide reference data for clinical research on the treatment of osteoporosis. METHODS: Chinese and English language databases, including Web of Science, PubMed, the Cochrane Library, Elsevier, Google Scholar, SpringerLink, Embase, China National Knowledge Infrastructure (CNKI), Weipu Chinese Sci-tech periodical full-text database (VIP), and Wanfang Data Knowledge Service Platform (Wanfang), were searched from their establishment to February 2020 using the following terms: "hongqu," "red yeast rice," "Monascus purpureus-fermented rice," "bone mineral density," "osteoblast," "osteoporosis," and "animal models." After excluding nonrelevant articles, Review Manager 5.2 was used to evaluate article quality and to analyze the data. Outcome indicators included bone mineral density (BMD), osteoblast proliferation, and the expression of alkaline phosphatase (ALP). RESULTS: A total of 11 randomized controlled trials were included in the meta-analysis, all of which were animal studies. Six studies included data on BMD, five on osteoblast proliferation, and six on the expression of ALP. The results of the meta-analysis showed that RYR can significantly improve BMD (standardized mean difference (SMD) = 3.12, 95% confidence interval (CI) 1.41 to 4.83, P = 0.0003), promote osteoblast proliferation (SMD = 1.64, 95% CI 1.04 to 2.23, P < 0.00001), and increase ALP expression in rats (SMD = 1.25, 95% CI 0.69 to 1.80, P < 0.00001). CONCLUSIONS: RYR can promote bone formation in experimental animals and may be useful for the treatment of osteoporosis.

Functional activity of anti-LINGO-1 antibody opicinumab requires target engagement at a secondary binding site.

LINGO-1 is a membrane protein of the central nervous system (CNS) that suppresses myelination of axons. Preclinical studies have revealed that blockade of LINGO-1 function leads to CNS repair in demyelinating animal models. The anti-LINGO-1 antibody Li81 (opicinumab), which blocks LINGO-1 function and shows robust remyelinating activity in animal models, is currently being investigated in a Phase 2 clinical trial as a potential treatment for individuals with relapsing forms of multiple sclerosis (AFFINITY: clinical trial.gov number NCT03222973). Li81 has the unusual feature that it contains two LINGO-1 binding sites: a classical site utilizing its complementarity-determining regions and a cryptic secondary site involving Li81 light chain framework residues that recruits a second LINGO-1 molecule only after engagement of the primary binding site. Concurrent binding at both sites leads to formation of a 2:2 complex of LINGO-1 with the Li81 antigen-binding fragment, and higher order complexes with intact Li81 antibody. To elucidate the role of the secondary binding site, we designed a series of Li81 variant constructs that eliminate it while retaining the classic site contacts. These Li81 mutants retained the high affinity binding to LINGO-1, but lost the antibody-induced oligodendrocyte progenitor cell (OPC) differentiation activity and myelination activity in OPC- dorsal root ganglion neuron cocultures seen with Li81. The mutations also attenuate antibody-induced internalization of LINGO-1 on cultured cortical neurons, OPCs, and cells over-expressing LINGO-1. Together these studies reveal that engagement at both LINGO-1 binding sites of Li81 is critical for robust functional activity of the antibody.

[Cannulated screw internal fixation for sustentaculum tali fractures with articular surface].

OBJECTIVE: To explore clinical efficacy of cannulated screw internal fixation in treating sustentaculum tali fractures with articular surface. METHODS: From August 2012 to June 2017, 13 sustentaculum tali fracture patients with articular surface were treated by cannulated screw internal fixation, including 10 males and 3 females, aged from 26 to 58 years old. Joint plane flatness was evaluated by calcaneal width, clearance distance of middle-range and posterior talar articular surface on coronal position of CT scan before operation and 1 year after operation. AOFAS score at 1 year after operation was applied to evaluate clinical efficacy. RESULTS: All patients were followed up from 9 to 70 months. The fractures were healed well from 8 to 16 weeks. No subtalar arthritis and tenosynovitis occurred. Calcaneal width before operation was from 46.2 to 52.7 mm, and decreased from 35.2 to 39.2 mm after operation; clearance distance of middle-range before operation was from 4.5 to 4.8 mm, and decreased from 1.9 to 2.2 mm after operation; clearance distance of posterior talar articular surface before operation was from 2.4 to 2.8 before operation, and decreased from 1.9 to 2.3 mm after operation. AOFAS score at 1 year after operation ranged from 77 to 94, and 1 got excellent result and 12 moderate. CONCLUSIONS: The clinical efficacy of two cannulated screws with cross internal fixation for sustentaculum tali fractures with articular surface is satisfactory, sustentaculum tali fracture could obtain good reduction, recover smooth of middle talar articular surface, and the function of feet were improved.

Effect of interference in YAP expression on apoptosis of bladder cancer cells by regulation of Wnt/β-catenin signaling pathway / 中国病理生理杂志

AIM:To investigate the effect of interference in Yes-associated protein(YAP)expression on blad-der cancer cell apoptosis and its mechanisms.METHODS:Bladder cancer cell line T-24 was used as the target and divid-ed into control group(no treatment),small interfering RNA negative control(siRNA-NC)group,and YAP siRNA group. The expression levels of YAP at mRNA and protein levels in the transfected cells of each group were detected by real -time PCR and Western blot,respectively.The cell viability was measured by MTT assay.The apoptosis was analyzed by flow cytometry.The protein expression levels of β-catenin and c-Myc were determined by Western blot.The cells in YAP siRNA group were treated with Wnt/β-catenin signaling pathway inhibitor FH 535, and then the cell viability and apoptosis were analyzed by MTT assay and flow cytometry,respectively.RESULTS:The expression of YAP at mRNA and protein levels in YAP siRNA group was significantly lower than that in control group(P<0.05).The cell viability and the expression levels of c-Myc and β-catenin in YAP siRNA group were significantly lower than those in control group(P<0.05),while the apoptotic rate was significantly higher than that in control group(P<0.05).The cell viability in YAP siRNA+FH535 group was decreased significantly,while the apoptotic rate was increased as compared with YAP siRNA group(P<0.05). CONCLUSION:Interfering with the expression of YAP inhibits the viability of bladder cancer cells by inhibiting the Wnt /β-catenin signaling pathway,thus promoting apoptosis of bladder cancer cells.

A Prodomain Fragment from the Proteolytic Activation of Growth Differentiation Factor 11 Remains Associated with the Mature Growth Factor and Keeps It Soluble.

Growth differentiation factor 11 (GDF11), a member of the transforming growth factor ß (TGF-ß) family, plays diverse roles in mammalian development. It is synthesized as a large, inactive precursor protein containing a prodomain, pro-GDF11, and exists as a homodimer. Activation requires two proteolytic processing steps that release the prodomains and transform latent pro-GDF11 into active mature GDF11. In studying proteolytic activation in vitro, we discovered that a 6-kDa prodomain peptide containing residues 60-114, PDP60-114, remained associated with the mature growth factor. Whereas the full-length prodomain of GDF11 is a functional antagonist, PDP60-114 had no impact on activity. The specific activity of the GDF11/PDP60-114 complex (EC50 = 1 nM) in a SMAD2/3 reporter assay was identical to that of mature GDF11 alone. PDP60-114 improved the solubility of mature GDF11 at neutral pH. As the growth factor normally aggregates/precipitates at neutral pH, PDP60-114 can be used as a solubility-enhancing formulation. Expression of two engineered constructs with PDP60-114 genetically fused to the mature domain of GDF11 through a 2x or 3x G4S linker produced soluble monomeric products that could be dimerized through redox reactions. The construct with a 3x G4S linker retained 10% activity (EC50 = 10 nM), whereas the construct connected with a 2x G4S linker could only be activated (EC50 = 2 nM) by protease treatment. Complex formation with PDP60-114 represents a new strategy for stabilizing GDF11 in an active state that may translate to other members of the TGF-ß family that form latent pro/mature domain complexes.

Determination of the Disulfide Structure of Murine Meteorin, a Neurotrophic Factor, by LC-MS and Electron Transfer Dissociation-High-Energy Collisional Dissociation Analysis of Proteolytic Fragments.

Meteorin and Cometin (Meteorin-like) are secreted proteins belonging to a newly discovered growth factor family. Both proteins play important roles in neural development and may have potential as therapeutic targets or agents. Meteorin and Cometin are homologues and contain ten evolutionarily conserved Cys residues across a wide variety of species. However, the status of the Cys residues has remained unknown. Here, we have successfully determined the disulfide structure for murine Meteorin by LC-MS analysis of fragments generated by trypsin plus endoprotease-Asp-N. For proteolytic fragments linked by more than one disulfide bond, we used electron transfer dissociation (ETD) to partially dissociate disulfide bonds followed by high-energy collisional dissociation (HCD) to determine disulfide linkages. Our analysis revealed that the ten Cys residues in murine Meteorin form five disulfide bonds with Cys7 (C1) linked to Cys28 (C2), Cys59 (C3) to Cys95 (C4), Cys148 (C5) to Cys219 (C8), Cys151 (C6) to Cys243 (C9), and Cys161 (C7) to Cys266 (C10). Since the ten Cys residues are highly conserved in Meteorin and Cometin, it is likely that the disulfide linkages are also conserved. This disulfide structure information should facilitate structure-function relationship studies on this new class of neurotrophic factors and also assist in evaluation of their therapeutic potentials.

[Comparison of core decompression with stem cell transplantation and tantalum rod implanting in treating stage II non-traumatic osteonecrosis of femoral head].

OBJECTIVE: To compare clinical effects of core decompression with stem cell transplantation and tantalum rod implanting in treating stage II non-traumatic osteonecrosis of femoral head. METHODS: From March 2012 to September 2012, 45 patients(55 hips)with stage ARCO II non-traumatic osteonecrosis of femoral head were treated and divided into core decompression with stem cell transplantation group(group A) and tantalum rod implanting group(group B) according to number table. In group A, there were 23 cases(28 hips) , including 12 males and 11 females aged from 23 to 51 years old with an average of (36.87±9.52) years, the courses of disease ranged from 2 to 28 months with an average of (17.13±7.74) months, preoperative Harris score was for 35 to 70 with an average of(54.74±11.81), treated with core decompression with stem cell transplantation. In group B, there were 22 cases(27 hips), including 11 males and 11 females aged from 26 to 46 years old with an average of (35.59±7.39) years, the courses of disease ranged from 3 to 26 months with an average of(16.00±7.46) months, preoperative Harris score was for 35 to 76 with an average of (57.18±12.95), treated with core tantalum rod implanting. Operative time, blood loss, hospital stays, hospitalization expenses were observed and compared after treatment between two groups, the clinical effects were evaluated according to Harris criteria. RESULTS: All patients were followed up from 6 to 12 months with an average of 10.8 months. There were significant difference in hospitalization expenses between two groups(P<0.05), while there was no significant statistical difference in blood loss and hospital stay (P>0.05). At the final following-up, Harris score in group A was(83.04±8.97), 6 cases obtained excellent results, 14 good, 2 good and 1 poor;while Harris score in group A was(84.41±9.94), and 9 cases obtained excellent results, 9 good, 3 good and 1 poor; there was no statistical meaning differences between two groups(P>0.05). CONCLUSIONS: Core decompression with stem cell transplantation and tantalum rod implanting could both improve function of hip joint, while core decompression with stem cell transplantation had advantages of shorter operation time, less cost, and higher potency ratio. It is suitable for stage ARCO II non-traumatic femoral head necrosis.

Comparison of core decompression with stem cell transplantation and tantalum rod implanting in treating stage II non-traumatic osteonecrosis of femoral head / 中国骨伤

<p><b>OBJECTIVE</b>To compare clinical effects of core decompression with stem cell transplantation and tantalum rod implanting in treating stage II non-traumatic osteonecrosis of femoral head.</p><p><b>METHODS</b>From March 2012 to September 2012, 45 patients(55 hips)with stage ARCO II non-traumatic osteonecrosis of femoral head were treated and divided into core decompression with stem cell transplantation group(group A) and tantalum rod implanting group(group B) according to number table. In group A, there were 23 cases(28 hips) , including 12 males and 11 females aged from 23 to 51 years old with an average of (36.87±9.52) years, the courses of disease ranged from 2 to 28 months with an average of (17.13±7.74) months, preoperative Harris score was for 35 to 70 with an average of(54.74±11.81), treated with core decompression with stem cell transplantation. In group B, there were 22 cases(27 hips), including 11 males and 11 females aged from 26 to 46 years old with an average of (35.59±7.39) years, the courses of disease ranged from 3 to 26 months with an average of(16.00±7.46) months, preoperative Harris score was for 35 to 76 with an average of (57.18±12.95), treated with core tantalum rod implanting. Operative time, blood loss, hospital stays, hospitalization expenses were observed and compared after treatment between two groups, the clinical effects were evaluated according to Harris criteria.</p><p><b>RESULTS</b>All patients were followed up from 6 to 12 months with an average of 10.8 months. There were significant difference in hospitalization expenses between two groups(<0.05), while there was no significant statistical difference in blood loss and hospital stay (>0.05). At the final following-up, Harris score in group A was(83.04±8.97), 6 cases obtained excellent results, 14 good, 2 good and 1 poor;while Harris score in group A was(84.41±9.94), and 9 cases obtained excellent results, 9 good, 3 good and 1 poor; there was no statistical meaning differences between two groups(>0.05).</p><p><b>CONCLUSIONS</b>Core decompression with stem cell transplantation and tantalum rod implanting could both improve function of hip joint, while core decompression with stem cell transplantation had advantages of shorter operation time, less cost, and higher potency ratio. It is suitable for stage ARCO II non-traumatic femoral head necrosis.</p>

Influence of pentylenetetrazol and NF-κB decoy oligodeoxynucleotides on p38 expression in neuron-like cells.

The aim of this study was to investigate the effects of pentylenetetrazol (PTZ) and nuclear factor κ B (NF-κB) decoy oligodeoxynucleotides (ODNs) on p38 expression in neuron-like PC12 cells. In addition, the role of NF-κB activation in the pathogenesis of epilepsy was explored. p38 expression levels in control and PTZ-treated neuron-like PC12 cells were examined using western blotting. NF-κB decoy ODNs were transfected into the neuron-like PC12 cells using Lipofectamine 2000. NF-κB activation was investigated by confocal laser scanning microscopy (CLSM), and p38 expression levels were assessed using western blotting prior to and following transfection of decoy ODNs. Western blot analysis revealed that p38 levels in PTZ-treated neuron-like PC12 cells were significantly higher than those in control cells. CLSM demonstrated that the decoy ODNs inhibited NF-κB activation in neuron-like PC12 cells, and western blotting indicated that the decoy ODNs did not reduce p38 levels. The results of this study indicate that PTZ enhances p38 expression levels and activates NF-κB in PC12 cells. However, NF-κB does not modulate p38 expression levels.

Effects and mechanism of low-intensity pulsed ultrasound on extracellular matrix in rabbit knee osteoarthritis / 中国骨伤

<p><b>OBJECTIVE</b>To observe the effects of low-intensity pulsed ultrasound (LIPUS) on repairing extracellular matrix in rabbit knee osteoarthritis and analyze its mechanism.</p><p><b>METHODS</b>Sixty adult female rabbits with an average weight of (2.0 ± 0.2) kg, were divided randomly into two groups (experimental group and control group, 30 rabbits in each group). All rabbits were replicated in right knees by Hulth method for knee osteoarthritis model. Two weeks after operation, the rabbits in experimental group were treated with LIPUS, and the ultrasonic frequency was (800 ± 5%)KHz and the maximum intensities of spatially averaged and time averaged (SATA) was (50 ± 10%) mw/cm2, for 1 time a day and every time 20 min, while the rabbits in control group were treated with sham LIPUS,the same operation with experimental group but without energy output. At the 2, 4, 8 weeks after treatment, 10 rabbits in each group were randomly killed for each time. The general changes of cartilage and its histopathological changes by HE staining were observed; the expression of collagen type II, proteoglycan, MMP-3, 7, 13 in cartilage were analyzed by immunohistochemical and RT-PCR technique; and the expression of NO in cartilage was analyzed by nitrate reduction method.</p><p><b>RESULTS</b>On the same observed time point, the damage degree of cartilage in experimental group was slighter than that of control group (P < 0.01), the expression of MMP-3, 7, 13 and NO in cartilage in experimental group was lower than that of control group (P < 0.01) while collagen type II and proteoglycan was higher than that of control group (P < 0.01).</p><p><b>CONCLUSION</b>Low-intensity pulsed ultrasound can repair the damaged cartilage by reducing the expression of MMP-3, 7, 13, inhibiting the secretion of NO and promoting the synthesis of collagen type II and proteoglycan in cartilage.</p>

[Effects and mechanism of low-intensity pulsed ultrasound on extracellular matrix in rabbit knee osteoarthritis].

OBJECTIVE: To observe the effects of low-intensity pulsed ultrasound (LIPUS) on repairing extracellular matrix in rabbit knee osteoarthritis and analyze its mechanism. METHODS: Sixty adult female rabbits with an average weight of (2.0 ± 0.2) kg, were divided randomly into two groups (experimental group and control group, 30 rabbits in each group). All rabbits were replicated in right knees by Hulth method for knee osteoarthritis model. Two weeks after operation, the rabbits in experimental group were treated with LIPUS, and the ultrasonic frequency was (800 ± 5%)KHz and the maximum intensities of spatially averaged and time averaged (SATA) was (50 ± 10%) mw/cm2, for 1 time a day and every time 20 min, while the rabbits in control group were treated with sham LIPUS,the same operation with experimental group but without energy output. At the 2, 4, 8 weeks after treatment, 10 rabbits in each group were randomly killed for each time. The general changes of cartilage and its histopathological changes by HE staining were observed; the expression of collagen type II, proteoglycan, MMP-3, 7, 13 in cartilage were analyzed by immunohistochemical and RT-PCR technique; and the expression of NO in cartilage was analyzed by nitrate reduction method. RESULTS: On the same observed time point, the damage degree of cartilage in experimental group was slighter than that of control group (P < 0.01), the expression of MMP-3, 7, 13 and NO in cartilage in experimental group was lower than that of control group (P < 0.01) while collagen type II and proteoglycan was higher than that of control group (P < 0.01). CONCLUSION: Low-intensity pulsed ultrasound can repair the damaged cartilage by reducing the expression of MMP-3, 7, 13, inhibiting the secretion of NO and promoting the synthesis of collagen type II and proteoglycan in cartilage.