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BACKGROUND:Mechanical stimulation has been confirmed to promote osteogenic differentiation of bone marrow stromal stem cells,but the mechanism is unknown.Primary cilia are important mechanoreceptors and regulate various signaling pathways such as TGF-β1/BMP-2/SMAD.They are likely to be important targets for mechanical regulation of bone marrow stromal stem cells. OBJECTIVE:To investigate the effect and mechanism of fluid shear stress on osteogenic differentiation of bone marrow stromal stem cells. METHODS:Rat bone marrow stromal stem cells were divided into control group,mechanical stimulation group(fluid shear mechanics intervention by shaking table),mechanical stimulation + IFT88 silencing group(mechanical stimulation + silencing IFT88 expression with siRNA).After 24 hours of intervention,qRT-PCR was utilized to determine the expression of transforming growth factor β1 and bone morphogenetic protein 2.Western blot assay was used to detect the expression of phosphorylated SMAD2/3 protein.Immunofluorescent staining of primary cilia was conducted and morphology was analyzed. RESULTS AND CONCLUSION:Shear stress stimulation could promote the transcriptional activity of transforming growth factor β1 and bone morphogenetic protein 2 genes,and increase the expression of phosphorylated SMAD2/3 protein.After siRNA interfered with primary cilia,this mechanical response effect was significantly reduced.There was a Spearman correlation between the change ratio of the primary cilium area of bone marrow stromal stem cells and the increased ratio of transforming growth factor β1 and bone morphogenetic protein 2 gene transcription.These findings indicate that primary cilia/intraflagellar transport mediates the activation of fluid shear stress-responsive transforming growth factor β1/bone morphogenetic protein 2/SMAD signaling pathway and promotes osteogenic differentiation of bone marrow stromal stem cells.
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Objective To explore the indications,feasibility and clinical outcome of minimally invasive laminoplasty for cervical spondylotic myelopathy (CSM) using microendoscopic technique.Methods From January 2011 to December 2013,51 patients with CSM treated by this technique in our hospital were reviewed in this study.All these patients were followed up at least 9 months.There were 28 males and 23 females with a mean age of 58 years (range 41-76 years).All patients were found to have cervical disc herniation with spinal cord compression.Among these patients,2 segments (C5-6),3 segments (C3-5/C4-6),4 segments (C3 -6) and 5 segments (C3-7) laminoplasty performed in 5,7,22 and 17 cases respectively.Therapy effect and axial symptom were evaluated according to Japanese Orthopedic Association (JOA) scores and visual analogue scales (VAS) respectively.Cervical curvature index (CCI) and range of motion (ROM) were judged by X-ray.The sagittal diameter of cervical spine,canal enlargement and bony healing were judged by CT scans.Spinal cord signal intensity changes and spinal cord decompression status judged by MRI.Statistical analysis of JOA score,VAS score,CCI and ROM were performed by paired design t test.Results The mean operative time was (1 15±21.9) min,ranging 58-139 min.The mean blood loss was (227.8±73.2) ml,ranging 110-380 ml.The followe-up time ranged 9-36 months with an average of (20±5.9) months..The mean JOA scores had improved from 8.02± 1.69 pre-operatively to 13.02± 1.48 post-operatively.The results were excellent in 17 cases,good in 28 and fair in 4.The VAS scores of axial pain significantly improved to 2.22±0.90 at the final follow-up compared with 4.96± 1.39 preoperatively.Axial symptom were excellent in 18 cases,good in 21 and fair in 12.Pre-operative was 15.40％±4.50％ and postoperative was 15.09％±4.87％,there was no significant difference.ROM of pre-operative was 40.98°±8.27° and postoperative was 38.88°±9.53°,and there was no significant difference.The sagittal diameter of the spinal canal increased 1.3-3.2 mm postoperatively with an average of (2.32±0.42) mm.A total of 204 vertebral lamina were bilaterally slotted and fixed.146 lamina were observed bone healing at the last follow-up.The bone healing rate was 71.6％.Complications such as upper limb motion dysfunction occurred in 1 case muscle strength restored after treatment of methylprednisolone sodium succinate,and little screw looseness in occurred 1 case,and non special treatment was given..Conclusion CMEL is a newsurgical approache which causes less damage to the spinous process-ligament complex and the deep extensor muscles,and the procedure can be used for CSM effectively and safely.
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Objective To determine the risk factors associated with surgical site infection in closed calcaneal fractures.Methods A retrospective analysis was made on the clinical data of 312 patients with closed calcaneal fracture who had been treated by open plate osteosynthesis at our trauma centre from January 2008 to November 2014.They were 182 males and 130 females,from 18 to 75 years of age (average,44.3 years).By Sanders classification,52 cases were type Ⅱ,146 type Ⅲ,and 114 type Ⅳ.The fractures were caused by fall from a height in 159 cases,traffic accident in 97 ones,and crushing in 56 ones.All the patients received open reduction and internal fixation via a typical L-shaped lateral incision.Gender,age,cause for injury,smoking history,diabetes,interval between injury and operation,operation time and bone grafting were analyzed as possible risk factors in the study.Multivariate logistic regression was conducted for significant risk factors derived from the univariate analysis.Results The patients were divided into an infection group (28 cases,9.0％) and a non-infection group (284 cases,91.0％).The univariate analysis showed that the rate of smoking was significantly higher,the operation time significantly longer,the interval between injury and operation significantly shorter in the infection group than in the non-infection group (P ＜ 0.05).However,the logistic regression analysis revealed that operation time was the only independent risk factor for surgical site infection (P =0.005,OR =43.870).Conclusion Since operation time may be an independent risk factor for surgical site infection in closed calcaneal fracture,it is important to speed up surgery as quick as possible in control of surgical site infection as long as the surgical quality is ensured.
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Objective To investigate the expression of TMPRSS4 mRNA,protein in human pancreatic cancer tissues and to explore the relationship between the expression of TMPRSS4 protein and the clinicopathologic parameters.Methods Real-time PCR and Western blotting were used to detect the expressions of TMPRSS4 mRNA and protein in 16 samples of pancreatic cancer tissues and adjacent normal pancreatic tissues.The expression of TMPRSS4 protein in 61 samples of pancreatic cancer tissues and 26 samples of adjacent pancreatic tissues and 4 samples of normal pancreatic tissues was detected by using immunohistochemistry and its relationship with clinicopathological features was analyzed.Results The expression of TMPRSS4 mRNA and protein of pancreatic cancer tissues were significantly higher than those in adjacent pancreatic tissues (9.09 ± 7.01 vs.1.27 ± 0.72; 1.223 ± 0.125 vs.0.667 ± 0.106,P ＜ 0.01 ) ;the expression rate of TMPRSS4 protein of pancreatic cancer tissues was 67.2％ (41/61),which were significantly higher than that in adjacent pancreatic tissues[3.8％ (1/26),P ＜ 0.01].There was no TMPRSS4 protein expression in normal pancreatic tissues.There was no significant correlation between the expression of TMPRSS4 protein and the age,gender,tumor location or tumor size was found.There was significant correlation between the expression of TMPRSS4 protein and the degree of differentiation,lymph node metastasis,and clinical staging (P ＜ 0.05 ).Conclusions TMPRSS4 protein is highly expressed in pancreatic cancer tissues,and the expression of TMPRSS4 is associated with the degree of malignancy of pancreatic cancer.