具有微弧氧化-硅烷-褪黑素复合膜层钛合金种植体的体内骨结合

BACKGROUND: Imperfect strength of titanium alloy implant-bone interface delays bone healing. OBJECTIVE: In order to further improve the early healing ability of titanium dental implants, to make the surface modification of titanium alloy implant and observe the osseointegration ability of the implant. METHODS: Titanium alloy implants were coated with micro-arc oxidation (group A), micro-arc oxidation-silane (group B), and micro-arc oxidation-silane-melatonin (group C) coatings, respectively. Three kinds of implants were placed into the mandible of New Zealand white rabbits, and 2, 4, 6 weeks after implantation, implant-bone interface osseointegration was observed using cone-beam CT, fluorescence microscopy, and torsion test. RESULTS AND CONCLUSION: (1) Cone-beam CT examination: 6 weeks after implantation, the osseointegration of the implant with the mandible achieved the best results in the group C, followed by group B and group A. (2) Fluorescence microscope observation: the implants in the three groups exhibited the strongest fluorescence at 4 weeks and slightly weakened at 6 weeks, and the fluorescence intensity was higher in the group C than the other two groups. (3) Torsion test: with implantation time prolonged, the implant-bone osseointegration activity gradually increased in the three groups, while it was still highest in the group C (P < 0.05). In summary, our results show that the titanium alloy implant coated with micro-arc oxidation-silane-melatonin composite coating has higher osseointegration activity and promotes bone formation.     

可吸收挤压螺钉关节镜下置入固定自体腘绳肌重建前交叉韧带

BACKGROUND: Arthroscopic reconstruction is a common method in the treatment of anterior cruciate ligament injury, in which tendon fixation is an important part. OBJECTIVE: To investigate the clinical effect of absorbable screw fixation with autologous hamstring for anterior cruciate ligament reconstruction under arthroscopy. METHODS: Totally 47 cases of anterior cruciate ligament reconstruction were included, containing 27 male patients and 20 female patients, aged from 18-48 years old, and all patients underwent the absorbable screw fixation with autologous hamstring implantation. After12-month follow-up, patients underwent Lysholm, Tegner, and IKDC scoring before treatment and after 1, 3, 6 and 12 months, respectively. Additionally, anterioposterior lateral X-ray and MRI reexamination were performed, and adverse reactions were recorded at 12 months after treatment. RESULTS AND CONCLUSION: Postoperative knee instability symptoms such as “weak legs” walking gait recovered to normal levels, and the wound all reached the primary healing. Moreover, the Lysholm, Tegner and IKDC scores at 3, 6 and 12 months after treatment were significantly higher than those before treatment (P < 0.05). There were no incision infection, nerve injury, deep vein thrombosis and other adverse events except hemarthrosis of the knee joint in one case. After 12 months of treatment, the imaging examinations showed that there was no enlargement of the bone tunnel, and no significant change in the joint space. In conclusion, the absorbable screw fixation with autologous hamstring for the reconstruction of anterior cross ligament has good fixing effect and little trauma, and significantly improves the extremity function of patients.      

人工颈椎间盘置换与前路颈椎间盘切除融合后邻近节段椎间盘应力分布的有限元对比

BACKGROUND: Previous clinical follow-up study showed that disc degeneration of adjacent segment after anterior cervical discectomy and fusion was faster than that of artificial cervical disc replacement. Compared with the anterior cervical discectomy and fusion, artificial cervical disc replacement can maintain a good range of motion of replacement segment. Further investigation should be taken to compare the difference between stress and fusion after replacement.      

股骨头坏死区三维数字化模型建立及体积估算

BACKGROUND: Core decompression and autogenous bone grafts are widely used in treatment of early avascular necrosis of femoral head. According to the report, the success rate of this therapy has obvious difference; the reasons may be related to inaccurate puncture location and secondary damnification of repeated puncture.      

骨髓间充质干细胞对创伤性骨折愈合的促进作用

BACKGROUND:In recent years, the development of stem cell culture and isolation technologies provides new therapeutic choices for fracture healing. OBJECTIVE:To investigate the effect of exogenous bone marrow mesenchymal stem cells on bone fracture healing in traumatic fracture rats and on the migration ability of endogenous bone marrow mesenchymal stem cells. METHODS:Femoral fracture models were made in 48 Wistar rats and then randomized into experimental group and control group (n=24/group). Bone marrow mesenchymal stem cells from another healthy rats were isolated using adherent method and then injected into the rats via the tail vein in the experimental group. Rats in the control group were given the same volume of normal saline. At 2, 3, 4, 8, 12 weeks after injection, we extracted bone marrow mesenchymal stem cells from the femur of rats in the two groups. RT-qPCR was used to detect expression levels of type I collagen and CD44. Transwell method was used to detect cell migration ability. Immunohistochemitry method was employed to detect expression of nerve growth factors in the callus. RESULTS AND CONCLUSION:mRNA levels of type I collagen and CD44 in rat bone marrow mesenchymal stem cells were significantly higher in the experimental group than the control group at 2, 3 and 4 weeks after injection (P < 0.05). Compared with the control group, the higher migration ability of bone marrow mesenchymal stem cells was found in the experimental group at 2 and 3 weeks after injection (P < 0.05) as well as the higher expression of nerve growth factor in the callus in the experimental group at 3, 4, 8, 12 weeks after injection. All these findings suggest that exogenous bone marrow mesenchymal stem cells can improve the migration ability of endogenous bone marrow mesenchymal stem cells and the expression of nerve growth factor in the callus in rats with femoral fracture, thereby promoting fracture healing in rats.     

miR-1231对结肠癌干细胞增殖、凋亡和侵袭的影响

BACKGROUND:Previous studies have found that miR-1231 is down-regulated in colon cancer stem cells (CCSCs), but the effect of miR-1231 on CCSCs remains unclear. OBJECTIVE:To explore the effect of miR-1231 on the proliferation, apoptosis and invasion of CCSCs (CD133⁺CD44⁺). METHODS: CD133⁺CD44⁺ cells and CD133^-CD44^- cells were separated from SW1116 cells by immunomagnetic bead separation. The expression level of miR-1231 in CD133⁺CD44⁺ and CD133^-CD44^- cells was detected by qRT-PCR. miR-1231-overexpressing CD133⁺CD44⁺ cells were transfected with miR-1231 mimics or miR-control by lipofection transfection. The effects of miR-1231 on CD133⁺CD44⁺ cell proliferation, apoptosis and invasion were investigated by MTT, flow cytometry and Transwell assays, respectively. In addition, the expression levels of Ki67, Bax, Bcl-2, MMP-2 and MMP-9 protein in miR-1231-overexpressing CD133+CD44+ cells and control cells were detected by western blot. RESULTS AND CONCLUSION:CD133⁺CD44⁺ and CD133^-CD44^- cells were obtained by the immunomagnetic bead separation. The expression level of miR-1231 in CD133⁺CD44⁺ cells was significantly lower than that in CD133^-CD44^- cells. miR-1231 suppressed CD133⁺CD44⁺ cell proliferation and invasion, but promoted the apoptosis in these cells. Western blot analysis showed that miR-1231-overexpressing CD133⁺CD44⁺ cells had obvious decreases in Ki67, Bcl-2, MMP-2 and MMP-9 protein expression and a significant increase in Bax protein expression compared with control cells. All these results further confirm that miR-1231 inhibits the proliferation and invasion but promotes the apoptosis in CD133⁺CD44⁺ cells. These findings suggest that miR-1231 can be a suppressor of CCSCs, which offers a novel potential therapeutic target for CCSCs and colon cancer.     

脐血干细胞移植干预妊娠期高血压模型大鼠的作用

BACKGROUND:With the depth understanding of mesenchymal stem cells, mesenchymal stem cells are found to exert a prominent effect on immune regulation and anti-inflammation. OBJECTIVE:To investigate the therapeutic effect of umbilical cord blood stem cell transplantation on endotoxin-induced hypertension in pregnant rats. METHODS:Twenty-four pregnant Sprague-Dawley rats were randomized into three groups with eight rats in each group: control, model and experimental groups. Endotoxin-induced hypertension models were made in the model and experimental groups. Meanwhile, rats were given intravenous injection of umbilical cord blood stem cell suspension (1 mL) in the experimental groups and the same volume of normal saline in the control and model groups. Therapeutic effects of umbilical cord blood stem cell transplantation were observed through detection of systolic blood pressure, urine protein level, serum white blood cell quantity and Ang II and ET-1 expression. RESULTS AND CONCLUSION:Compared with the control group, the systolic blood pressure, urine protein level and serum white blood cell quantity of rats were increased significantly in the model group, and over time, endotoxin continuously promoted these parameters in the model group. After cell transplantation, a significant reduction in systolic blood pressure, urine protein level and serum white blood cell quantity of rats was found in the experimental group compared with the model group (P < 0.05). After modeling, the expression levels of Ang II and ET-1 were decreased significantly, while these levels were increased significantly after cell transplantation (P < 0.05). These findings indicate that umbilical cord blood stem cell transplantation may have a certain therapeutic effect on gestational hypertension in rats, which may be realized by regulating the secretion of endothelial injury-related factors.     

微创后路经皮椎弓根螺钉内固定修复单纯前中柱损伤的急性胸腰椎骨折：回顾性、自身前后对照临床试验方案

BACKGROUND: Posterior pedicle screw fixation is commonly used for thoracolumbar fracture. However, associated disadvantages include severe trauma, extensive bleeding, long rehabilitation time, and long postoperative duration of intractable lumbar stiffness and low back pain. Percutaneous pedicle screw external fixation can reduce injury caused by screw insertion into the paraspinal muscles; particularly in acute thoracolumbar vertebral compression fracture with simple anterior spinal column injury. We hypothesized that minimally invasive posterior percutaneous pedicle screw fixation for acute thoracolumbar vertebral fractures with simple anterior spinal column injury would exhibit good curative effects.     

过表达Shootin1的骨髓间充质干细胞移植治疗脊髓损伤

BACKGROUND:Genetic modification by Shootin1 aims to effectively improve neural differentiation of bone marrow mesechymal stem cells (BMSCs) in the injured spinal cord, thereby promoting functional recovery from spinal cord injury after cell transplantation. OBJECTIVE:To explore the nerve regeneration ability of transplanted BMSCs overexpressing Shootin1 in rats with spinal cord injury. METHODS:BMSCs were transfected using adenovirus-Shootin1 for 48 hours. Then, immunofluorescence staining was used to detect Nestin and NeuN expression levels in the transfected cells under in vitro neuronal induction and differentiation. Animal models of spinal cord injury were made in rats using modified Allen’s method. Thirty minutes later, Shootin1-transfected BMSCs and non-transfected BMSCs were respectively injected into the subarachnoid space of the rats in the transfection and non-transfection groups, respectively. Rats in the model group were given no treatment. Five weeks after modeling, spinal cord samples were taken from each rat to make frozen sections for detection of nerve related markers RESULTS AND CONCLUSION:After 48-hour adenoviral transfection, Shootin1 expression was successfully detected in BMSCs. After 7-day in vitro induction, the cell morphology in the three groups varied, and there was no significant difference in the expression of Nestin and NeuN between the transfection and non-transfection groups. Basso, Beattie and Bresnahan scores were higher in the two cell transplantation groups than the model group. Increased expression levels of Nestin, NeuN, GFAP, MAP-2, ChAT and SYN were observed in both two cell transplantation groups, indicating a strengthened ability of nerve regeneration. Our experimental findings further confirm that BMSCs transplantation for spinal cord injury has achieved good outcomes, and Shootin1 protein plays a certain role in nerve regeneration and functional recovery after spinal cord injury. However, Shootin1 overexpression shows no obvious additional effects in combination with BMSCs transplantation, and further studies on the optimization of BMSCs transplantation for spinal cord injury are necessary.