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Objective:To study the effect of microglia depletion combined with bone marrow mesenchymal stem cells (BMSC) transplantation for spinal cord injury (SCI) repair.Methods:GFP-BMSCs were cultured, identified and detected for expression levels of growth factors. The effects of BMSCs ondorsal root ganglion (DRG) axon outgrowth were observed by the co-culture of BMSCs with DRGs. Mice were depleted of microglia by administrating the colony stimulating factor 1 receptor (CSF1R) inhibitor PLX3397. The spinal cords of these microglia-depleted mice were subjected to crush injury. BMSCs were transplanted into SCI area after microglia depletion. Mice were randomly divided into control group (SCI+BMSCs) and experimental group (PLX3397+SCI+BMSCs). Mice were sacrificed at corresponding time points after transplantation for observing the survival of transplanted BMSCs and the repair of spinal cord. BMS score was used for evaluation of motor function recovery.Results:BMSCs secreted a large number of neurotrophic factors and promoted the growth of DRG axons when co-cultured with DRGs. Depletion of microglia significantly improved the survival of transplanted BMSCs. Compared with BMSCs transplantation alone, the combined treatments slightly but non-significantly reduced the area of the lesion ( t=2.141, P=0.065). Immunofluorescence staining showed that both BMSC transplantation alone and the combined treatments did not cause the corticospinalaxons across the lesion and into distal spinal cord. BMS scores were (1.20±0.45), (3.20±0.45), (3.80±0.45), (4.20±0.45), and (4.60±0.55) points in control group at 1, 7, 14, 21 and 28 d after injury. The experimental groups were(0.60±0.55), (3.00±0.71), (3.80±0.84), (4.20±0.84), and (4.40±0.89) points, respectively. Conclusion:Depletion of microglia improves the survival of transplanted cells, depletion of microglia combined with BMSC transplantation did not result in a significant reduction in lesion area. At the same time, the damaged CST axons were notregenerated. Thus, combining cell transplantation with axon-promoting strategy may be necessary for SCI repair.
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Objective:To explore the clinical effectiveness of arthroscopic treatment of tibial eminence avulsion fracture by four-point fixation with suture anchors.Methods:A retrospective analysis was performed of the 58 patients with tibial eminence avulsion fracture who had been treated by the same group of surgeons using four-point fixation technique with suture anchors under arthroscopy at Department of Sports Medicine, The Affiliated Hospital to Qingdao University from January 2015 to December 2018. They were 33 males and 25 females, with an average age of 18.4 years (from 14 to 32 years). By the modified Meyers-McKeever classification, 15 fractures were type Ⅱ, 19 type Ⅲ and 24 type Ⅳ. Recorded and compared were knee Lysholm scores, International Knee Documentation Committee (IKDC) scores and tibial eminence height between preoperation and one year postoperation; recorded at the last follow-up were range of knee motion and results of Lachman and pivot-shift tests.Results:The 58 patients were followed up for a mean of 20.7 months (from 12 to 33 months). Bony union was achieved in all patients within 12 weeks after operation. In this cohort, the Lysholm score (85.2±4.9) and IKDC score (86.2±4.3) at one year postoperation were significantly higher than the preoperative values (43.2±5.2 and 51.2±4.9), and the post-operative tibial eminence height [(9.1±1.2) mm] was significantly lower than the preoperative value [(12.6±1.2) mm] (all P<0.05). The correlation coefficients between the tibial eminence height and the Lysholm & IKDC scores at one year postoperation were -0.16 and -0.17, respectively. The last follow-up showed a 132°±5° range of knee motion for all patients, a positive result of pivot-shift test (grade Ⅱ) for 3 and a positive result of Lachman test (grade Ⅰ) for 2. Conclusion:Arthroscopic treatment of tibial eminence avulsion fracture by four-point fixation with suture anchors can lead to satisfactory effectiveness, showing advantages of minimal invasion, anatomic reduction, reliable fixation, and little impact on the epiphysis plate.
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Tendon injuries often need surgical treatment, which enables to repair the structure and stability of the tendons to a certain extent, whereas it is difficult to restore to their normal strength. The primary reason is that the natural healing ability of tendons is limited and the functions of the repaired tendons cannot be restored completely. As further researches on tendon healing are conducted, biological technology provides a novel orientation for tendon repair. One of the research hotspots of tendon repair currently is to facilitate tendon healing using biological auxiliaries, including tendon stem /progenitor cells(TSPCs) and growth factors. The authors review the research progress in mechanism of TSPCs and growth factors accelerating tendon healing in order to provide a reference for the biological treatment of tendon injuries.
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BACKGROUND:Bacterial biofilm is the main cause of the infection of the prosthesis.In vitro experiments confirmed that hypertonic sodium chloride and ethanol can apparently promote the formation of staphylococcal biofilms. There are no reports on the effects of ethanol and hypertonic environment surrounding the prosthesis on the formation of biofilms. OBJECTIVE: To evaluate the effects of different environment factors surrounding the prosthesis on the growth of Staphylococcus epidermidis and bacterial biofilm formation after replacement. METHODS: White rabbit models infected with Staphylococcus epidermidis on the prosthesis were established, and were randomly divided into hypertonic sodium chloride, ethanol and control groups (n=15). The bacteria were injected with 0.1 mL 4% sodium chloride and 4% ethanol into the knee of rabbits in the hypertonic sodium chloride and ethanol groups. The rabbits were injected with 0.1 mL 0.9% sodium chloride in the control group. Three rabbits were sacrificed at 2, 4, 6, 8 and 16 days after inoculated with bacteria. Synovial fluid, prosthesis and tissue surrounding infection were obtained. Bacterium was cultured to extract total RNA. The ica operon transcription levels were detected in the gene levels. Adhesion of bacteria on the surface of the prosthesis was observed using a scanning electron microscope. Tissues surrounding the prosthesis were observed using hematoxylin-eosin staining. RESULTS AND CONCLUSION:Histological examination revealed that inflammatory cel infiltration was observed in al the rabbits at 4 days after injection. Colony formation was found at 16 days after injection. At 6 days after injection, inflammatory cel infiltration was observed in the ethanol and control groups. Scanning electron microscope showed that compared with the control group, the bacteria adhered to the prosthetic surface became more in the hypertonic sodium chloride and ethanol groups at 6, 8 and 16 days (P < 0.05). At 6, 8 and 16 days, the expression of icaA mRNA was significantly higher in the hypertonic sodium chloride and ethanol groups than in the control group (P < 0.05). These data showed that the environment factors could affect the growth of Staphylococcus epidermidis and bacterial biofilm formation.