OBJECTIVE: To investigate a animal model of spinal cord injury in different degrees of impact. METHODS: A new weight-drop device was designed with the character of controlled degree of impact and time. After thirty-five rats underwent different degrees of impact, their motor function and pathological changes were observed. RESULTS: In control group, the rats could walk after reviving, and the micro-structure of spinal cord was normal. With 0.5 mm depth of impact, the rats also could walk, and the micro-structure of spinal cord did not change obviously. With 0.8 mm depth of impact, the rats could walk after several days of injury and only slight damage could be found in spinal cord. When the impact depth increased to 1.0 or 1.5 mm, the rats were paralyzed completely and could not walk after four weeks of injury. Severe injury was observed in spinal cord. CONCLUSION: This animal model of spinal cord injury is based on different degrees of impact. It has stable and repetitive characters for the research on spinal cord injury.
ObjectiveTo investigate the effects of bone marrow mesenchymal stem cells (BMSCs) transplantation for treating spinal cord injury (SCI) in rat and the cytokine expression changes in the local injury tissues. MethodsBMSCs were separated from Sprague Dawley (SD) rat and cultured with the whole bone marrow culture method. rAd-EGFP was used to transfect the 5th generation BMSCs for green fluorescent protein (GFP) label. Twelve SD rats were randomly divided into experimental group (n=6) and control group (n=6). After the T10 SCI model was established with Allen's impact device in 2 groups, 1×106 GFP-labeled BMSCs and PBS were administered by subarachnoid injection in situ in experimental group and control group, respectively. Basso-Beattie-Bresnahan (BBB) score was used to detect the motor function at immediat, 1, 2, 3, 4, and 5 weeks after SCI. At 5 weeks, the spinal cord tissues were harvested for the histological and immunofluorescent staining examinations to measure the expressions of neural marker molecules, including Nestin, glial fibrillary acidic protein (GFAP), and neuron-specific nuclear protein (NeuN). Cytokine was analyzed with antibody array. ResultsAt 5 weeks, 2 rats died of urinary tract infection in 2 groups respectively, the other rats survived to the end of experiment. BBB score of experimental group was significantly higher than that of control group at 1, 2, 3, 4, and 5 weeks (P < 0.05). At 5 weeks, histological results showed that there were many cells with regular arrangement in the experimental group; there were less cells with irregular arrangement in the control group. Compared with the control group, Nestin and NeuN expressions significantly increased (P < 0.05), and GFAP expression significantly decreased (P < 0.05) in the experimental group. Leptin and ciliary neurotrophic factor levels were higher in the experimental group than the control group, but granulocyte-macrophage colony-stimulating factor, tumor necrosis factorα, interleukin 1β, and tissue inhibitor of metalloproteinases 1 levels were lower in the experimental group than the control group. ConclusionBMSCs transplantation can improve survival and regeneration of nerve cells and enhances the recovery of nerve function by regulating secretion of cytokines from grafted BMSCs.
Objective To establish the artificial bladder reflex arc by the normal body reflex pathway above the horizon of spinal cord injury to reinnervate the flaccid bladder and restore bladder micturition function. Methods An intradural microanastomosis was performed on the L6 ventral root tothe S2 ventral root. After axonal regeneration,the “patellar ligament-spinal cord center-bladder” reflex pathway was reestablished. A longterm function of the reflex arc was observed in the nerve electrophysiological experiment, detrusor electromyography experiment, and urodynamic testing 8 months after anastomosis. Results Trains of the stimuli(200 μV,5 ms) in the left L6 dorsal root and the nerve at the anastomosizedsite resulted in motor evoked potential from the disal to the anastomosized site before and after the spinal cord was destroyed horizontally between S1 and S4 segment levels in 2 Beegle dogs.The figure and amplitude of the evoked potential were similar to those of the control and general stability which showed anoninterventional wave. The urodynamic test revealed a rapid increase of the bladder pressure and a minor increase in the abdominal pressure. This showed that the bladder detrusor mainly resulted in the pressure increase.The bladder pressure increased to 60% of the normal on average compared with the controls when resulted in the left L6 dorsal root and the nerve anastomosized site were stinulated. Conclusion The long-term observation by the nerveelectrophysiological experiment, detrusor electromyography experiment, and urodynamic test indicate that the new artificial reflex arc can be established successfully. The somatic motor axons can regenerate into the parasympathetic endoneurial tubes of the autonomic nerve.
Objective To evaluate the biomechanical characteristicsof titanium mesh with anterior plate fixation or ilium autograft in anterior cervical decompression.Methods Six fresh cervical spine specimens(C3-7) of young cadaver were used in the biomechanical test. After C5, C5,6 and C4-6 were given vertebrectomy,ilium autograft and titanium mesh with anterior plate fixation were performed. Their stabilities of flexion,bilateral axial rotation,the lateral bending and the extension were tested. Intact cervical spine specimens served as control group. Results Ilium autograft improved the stability of the unstable cervical vertebrae and decreased the flexion, the lateral bending or the extension, showing a significant difference when compared with control group(Plt;0.05). Whereas, axial rotational motion was decreased insignificantly(Pgt;0.05). Titanium meshwith anterior plate fixation improved the stability of the unstable spine and decreased the flexion,the bilateral axial rotation,the lateral bending or the extension, showing a significant difference when compared with control group(Plt;0.05). Conclusion The vertebrectomy and anterior cervical fusion by ilium autograft was the least stable construct of all modes tested,and the titanium mesh implantation is stabler than the intact cervical sample.
A new fixator for spine was designed to restore the stability of spine in improving the treatment of thoraco-lumbar dislocation. This instrument was composed of six nails, two longitudinal connecting rods and two transverse connecting rods. On the surface of the nails, there were furrows engraved, instead of screw thread. It fixed the spine through pedicle of vertebra from the posterior approach. The fixed vertebrae were limited between two vertebrae. From 1989 th 1995, twelve patients with fracture-dislocation of thoraco-lumbar spine were reduced with this instrument. After four years follow-up, it showed that the deformity was corrected and the spine firmly fixed. Compared with Dick’s screws, it had the following advantages such as simple manipulation, increased strergth of nails and minimal damage to tissue during operation.
Objective To explore the feasibilities, methods, outcomes and indications of atlas pedicle screw system fixation and fusion for the treatment of upper cervical diseases. Methods From October 2004 to January 2006, 17 patients with upper cervical diseases were treated with atlas pedicle screw system fixation and fusion. There were 13 males and 4 females, ageing 19 to 52 years. Of 17 cases, there were 14 cases of atlantoaxial dislocation(including 3 cases of congenital odontoid disconnection，4 cases of old odontoid fracture，2 cases of new odontoid fracture(typeⅡC), 3 cases of rupture of the transverse ligament, and 2 cases of atlas fracture； 2 cases of tumor of C2; 1case of giant neurilemoma of C2,3 with instability after the resection oftumors. JOA score before operation was 8.3±3.0. Results The mean operative time and bleeding amount were 2.7 hours (2.1-3.4 hours) and 490 ml (300-750 ml) respectively. No injuries to the vertebral artery and spinal cord were observed. The medial-superior cortex of lateral mass was penetrated by 1 C1 screw approximately 3 mmwithout affecting occipito-atlantal motions. All patients were followed up 3-18 months. The clinical symptoms were improved in some extents and the screws were verified to be in a proper position, no breakage or loosening of screw and rob occurred. All patients achieved a solid bone fusion after 3-6 months. JOA score 3 months after operation was14.6±2.2. JOA improvement rates were 73%-91%(mean 82%). Conclusion The atlas pedicle screw system fixation and fusion is feasible for the treatment of upper cervical diseases and has betteroutcomes, wider indications if conducted properly.
Objective To investigate the method of cultivation and the feature of differentiation of spinal cordderived stem cells in vitro.Methods The neural stemcells from spinal cord of 15 days fetal rats were harvested and cultivated in aserumfree limited medium. The stem cells were induced to differentiate and theresults were identified by cellular immunohistochemistry. Results Lots of stem cells were obtained from the spinal cord of fetal rats and the sphere of stemcells was formed about 10 days. Neural stem cells can give rise to mature neurons and astrocytes.Conclusion Epidermal growth factor/basic fibroblast growth factor serum-free limited medium can promote the proliferation activity ofthe stem cells. Spinal cord-derived stem cells can differentiate into glial cells and neurons.
Objective To explore the construction of a canine model of vascularized allogeneic spinal cord transplantation (vASCT) and preliminarily evaluate its therapeutic efficacy for spinal cord injury (SCI). Methods Sixteen female Beagle dogs aged 8-12 months were randomly selected, with 8 dogs serving as donors for the harvesting of spinal cord tissue with a vascular pedicle [dorsal intercostal artery (DIA) at the T10 level and accompanying vein]. The remaining 8 dogs underwent a 1.5-cm-length spinal cord defect at the T10 level, followed by transplantation of the donor spinal cord tissue for repair. Polyethylene glycol (PEG) was applied to both ends to spinal cord graft; then, using a random number table method, the dogs were divided into an experimental group (n=4) and a control group (n=4). The experimental group received immunosuppressive intervention with oral tacrolimus [0.1 mg/(kg∙d)] postoperatively, while the control group received no treatment. The operation time and ischemia-reperfusion time of two groups were recorded. The recovery of hind limb function was estimated by Olby score within 2 months after operation; the motor evoked potentials (MEP) was measured through neuroelectrophysiological examination, and the spinal cord integrity was observed through MRI. ResultsThere was no significant difference in the operation time and ischemia-reperfusion time between the two groups (P>0.05). All dogs survived until the completion of the experiment. Within 2 months after operation, all dogs in the control group failed to regain the movement function of hind limbs, and Olby scores were all 0. In the experimental group, the movement and weight-bearing, as well as walking abilities of the hind limbs gradually recovered, and the Olby scores also showed a gradually increasing trend. There was a significant difference between the two groups from 3 to 8 weeks after operation (P<0.05). Neuroelectrophysiological examination indicated that the electrical signals of the experimental group passed through the transplanted area, and the latency was shortened compared to that at 1 month after operation (P<0.05), showing continuous improvement, but the amplitude did not show significant improvement (P>0.05). The control group was unable to detect any MEP changes after operation. MRI examination showed that the transplanted spinal cord in the experimental group survived and had good continuity with normal spinal cord tissue, while no relevant change was observed in the control group. ConclusionThe vASCT model of dogs was successfully constructed. This surgical procedure can restore the continuity of the spinal cord. The combination of tacrolimus anti-immunity is a key factor for the success of transplantation.
ObjectiveTo investigate the expression changes of the receptor activator of nuclear factor-κB ligand (RANKL) in the peripheral blood of patients with aseptic loosening of the implant after total hip arthroplasty (THA) by comparing with that of patients with femoral neck fracture and to analyze the correlation between RANKL expression and aseptic loosening. MethodsBetween January 2008 and January 2013,the peripheral blood were harvested from 58 patients with aseptic loosening of the implant after THA (trial group) and 63 patients with femoral neck fracture (control group).The 2 groups were well matched,with no significant differences in age and gender (P>0.05).The expressions of the RANKL mRNA and RANKL protein were evaluated by quantitative real-time PCR and Western blot respectively.At the same time,the concentration of RANKL was also measured by ELISA. ResultsThe expression of the RANKL mRNA in the trial group was 18.30±1.09,which was significantly higher than that of control group (1.00±0.05)(t=125.390,P=0.000).The relative RANKL protein expression values in trial group and control group were 0.856±0.254 and 0.404±0.102 respectively,showing significant difference (t=13.032,P=0.000).The results of ELISA showed that the concentration of RANKL in trial group [(3.553 5±0.129 7) ng/mL] was significantly higher than that of control group [(1.912 3±0.126 2) ng/mL] (t=18.124,P=0.000). ConclusionThe high RANKL expression in peripheral blood is probably correlated with aseptic loosening of the implant in patients undergoing THA,which possibly is the prognostic factor of aseptic loosening of the implant.
OBJECTIVE: To observe the clinical results in the anterior stabile operation of spinal fracture using red blood salvage. METHODS: Nineteen cases with spinal fracture were performed the anterior decompress operation. Blood cell salvage were used during operation. Other 20 cases were also reviewed as control group, who were received the same operation without blood cell salvage. RESULTS: In the 19 cases, average volume of autologous transfusion was 536 ml. Only two cases had homologous transfusion requirements. In the control group, all cases needed homologous transfusion (averaged 947 ml). CONCLUSION: In the anterior decompress operation, the intraoperative blood salvage is highly effective in reducing transfusion and also improves the security of operation