Objective To investigate the mechanism of protective effects of resveratrol on tissueengineered cartilage.Methods The chondrogenesis of alginate-encapsulated bone marrow mesenchymal stem cells (BMSCs) were evaluated by toluidine blue staining and immunostain.The morphology of BMSCs-derived chondrocytes cultured on chitosan-gelatin scaffolds (CGS) was evaluated by scanning electron microscope and laser confocal microscope.When these cells on CGS were pre-stimulated with interleukin-1β (IL-1β) or cotreated with IL-1β and resveratrol in the absence and presence of specific β1-integrin blocking antibody,collagen type Ⅱ,aggrecan,matrix metalloproteinase-13 (MMP-13) expression,and the translocation of nuclear factor kappaB (NF-κB) were analyzed by Western blotting.ANOVA was used for statistical analysis.Results Alginate bead culture plus conditional medium together could induce the cartilage-specific collagen type Ⅱ,aggrecan expression and extracellular matrix accumulation in differentiated chondrocytes.CGS supported differentiated cell attachment,proliferation,and migration.When those cells cultured on CGS were stimulated with IL-1β alone,collagen type Ⅱ and aggrecan expression was inhibited.However,MMP-13 expression increased.By Western blotting semi-quantitative analysis,the expression level of cartilage-specific collagen type Ⅱ of the control group was 0.484±0.006; the expression level of resveratrol intervention group was 0.474±0.014.The difference between these two groups was not statistically significant (P＞0.05).The expression level of the IL-1β intervention group reduced to 0.155±0.009,which was statistically significant different from the above two groups(P＜0.05).Resveratrol could antagonist the negative effect of IL-1β,and increase collagen type Ⅱ to 0.468±0.014,the difference between these two was statistically significant (P＜0.05),and no significant difference when compared to the control group (P＞0.05).Specific β1-integrin blocking antibody could abrogate these effects of resveratrol,decrease collagen Ⅱ expression to 0.169±0.011,the difference was significant (P＜0.05),but there was no difference when compared to the IL-1β group (P＞0.05).Aggrecan semi-quantitative expression has the same trend in the expression of type Ⅱ collagen while the expression of MMP-13,NF-κB had the reversal trend.These indicated that the resveratrol reversed the catabolic effects by reducing the nuclear translocation of NF-κB.Specific β1-integrin blocking antibody abrogated these effects of resveratrol.Conclusion Resveratrol,by regulating β1-integrin,acts as a NF-κB nuclear trans-location inhibitor to protect tissue-engineered cartilage.

Objective To evaluate the safety of Renaissance spine robot assisted system in spinal injury.Methods From March 2014 to May 2016,38 patients with spinal disease received spinal surgery assisted by spine robot system.They were 20 males and 18 females,with an average age of 42 years (range,from 12 to 69 years).There were 10 lumbar fractures,8 thoracic fractures and 20 spinal deformities.Pedicle screw implantation was conducted in 30 patients (PS group) and percutaneous vertebroplasty in 8 (PV group).One side was chosen randomly to use Mazor spine robot assisted system (assisted group) and the opposite side the conventional method (non-assisted group).The anteroposterior and lateral X-rays and CT scan of the lumbar and/or thoracic spine were performed in all patients after surgery.The precision of pedicle screws implantation in PS group was evaluated by the Abul-Kasimhierarchy grading system;location of the puncture trajectory,time used for puncture and radiation exposure time in PV group were evaluated.Results 208 pedicle screws were implanted in PS group,including 120 lumbar ones and 88 thoracic ones.For lumbar pedicle screw implantation,the excellent to good rate was 95.0％ (57/60) in the assisted group,significantly higher than that in the non-assisted group (80.0％,48/60) (P ＜ 0.05).For thoracic pedicle screw implantation,the excellent to good rate was 95.5％ (42/44) in the assisted group,significantly higher than that in the non-assisted group (77.3％,34/44) (P ＜ 0.05).There were 24 puncture trajectories in 8 patients in PV group,showing no pedicle penetration or cement leaking in any case.The mean time used for puncture was 5.5 ± 1.4 min in the assisted group,significantly shorter than that in the non-assisted group (17.8 ± 7.5 min) (P ＜ 0.05);the X-ray exposure time was 14.0 ± 4.0 s in the assisted group,significantly shorter than that in the non-assisted group (22.4 ± 6.0 s) (P ＜ 0.05).Conclusions Renaissance spine robot-assisted system deserves more clinical application,because in spinal surgery it can make pedicle screw implantation more precise and safer,and can reduce operation time and X-ray exposure time in percutaneous vertebroplasty.

Objective:To explore the significance of digital orthopedic technology in surgical plan for spinal tumor and the preliminary outcomes of 3D printed vertebral bodies in spinal tumor surgery.Methods:The clinical data of 2 patients were retrospectively analyzed who had had a 3D printed vertebral body implanted at Center of Orthopaedics, Shenzhen Hospital from June 2018 to December 2019. One was a 32-year-old male, diagnosed with cervical neurinoma; the other was a 27-year-old female, diagnosed with giant cell tumor of lumbar bone. 3D virtual reconstruction of tumor and surrounding structures was established via Mimics software for surgical plan. Virtual osteotomy was simulated, their disease models and guide templates were 3D printed, and their metal artificial vertebral bodies were 3D printed after personalized design of the vertebral body diameter, porosity and procedures of reconstruction and fixation. Lesion resection and prosthesis implantation were carried out in accordance with the preoperative plan. After operation, the motor function of cervical or lumbar vertebrae, tumor recurrence, and spinal stability reconstructed were regularly observed.Results:Resections and reconstructions went uneventfully in both cases. The 2 patients were followed up for 21 and 13 months respectively. Their postoperative images showed that their 3D printed vertebral bodies fitted the neighboring vertebral bodies well. The spinal stability was reconstructed without any loosening or periprosthetic osteolysis, and the tumors were removed completely with no recurrence in both cases. Their spinal motor function was satisfactory.Conclusions:Digital orthopedic technology can offer accurate guidance in the treatment of spinal tumors. It is necessary to consider local physiological anatomy in personalized design of a metal vertebral body 3D printed. Clinical application of 3D printed metal vertebral bodies is a new strategy for spinal reconstruction following spinal tumor resection.

The finite element method is a new method to study the mechanism of brain injury caused by blunt instruments. But it is not easy to be applied because of its technology barrier of time-consuming and strong professionalism. In this study, a rapid and quantitative evaluation method was investigated to analyze the craniocerebral injury induced by blunt sticks based on convolutional neural network and finite element method. The velocity curve of stick struck and the maximum principal strain of brain tissue (cerebrum, corpus callosum, cerebellum and brainstem) from the finite element simulation were used as the input and output parameters of the convolutional neural network The convolutional neural network was trained and optimized by using the 10-fold cross-validation method. The Mean Absolute Error (MAE), Mean Square Error (MSE), and Goodness of Fit ( R ²) of the finally selected convolutional neural network model for the prediction of the maximum principal strain of the cerebrum were 0.084, 0.014, and 0.92, respectively. The predicted results of the maximum principal strain of the corpus callosum were 0.062, 0.007, 0.90, respectively. The predicted results of the maximum principal strain of the cerebellum and brainstem were 0.075, 0.011, and 0.94, respectively. These results show that the research and development of the deep convolutional neural network can quickly and accurately assess the local brain injury caused by the sticks blow, and have important application value for understanding the quantitative evaluation and the brain injury caused by the sticks struck. At the same time, this technology improves the computational efficiency and can provide a basis reference for transforming the current acceleration-based brain injury research into a focus on local brain injury research.
Brain ; Brain Injuries ; Computer Simulation ; Finite Element Analysis ; Humans ; Neural Networks, Computer