Objective To determine the feasibility, safety, and efficacy of common pedicle screw placement under direct vision combined with dome shaped decompression via small incision for double segment thoracolumbar fracture with nerve injury. Methods A retrospective analysis was performed on the clinical data of 32 patients with double segment thoracolumbar fracture with nerve injury undergoing common pedicle screw placement under direct vision combined with dome shaped decompression via small incision between November 2011 and November 2015 (combined surgery group), and another 32 patients undergoing traditional open pedicle screw fixation surgery (traditional surgery group). There was no significant difference in gender, age, cause of injury, time of injury-to-surgery, injury segments and Frankel classification of neurological function between two groups (P>0.05). The length of soft tissue dissection, the operative time, the blood loss during surgery, the postoperative drainage, the visual analogue scale (VAS) of incision after surgery, and recovery of neurological function after surgery were evaluated. Results All cases were followed up 9 to 12 months (mean, 10.5 months) in combined surgery group, and 8 to 12 months (mean, 9.8 months) in traditional surgery group. The length of soft tissue dissection, the operative time, the blood loss during surgery, the postoperative drainage, and the postoperative VAS score in the combined surgery group were significantly better than those in the traditional surgery group (P<0.05). Dural rupture during surgery and pedicle screw pulling-out at 6 months after surgery occurred in 2 cases and 1 case of the combined surgery group; dural rupture during surgery occurred in 1 case of the traditional surgery group. The X-ray films showed good decompression, and fracture healing; A certain degree of neurological function recovery was achieved in two groups. Conclusion Common pedicle screw placement under direct vision combined with dome shaped decompression via small incision can significantly reduce iatrogenic trauma and provide good nerve decompression. Therefore, it is a safe, effective, and minimally invasive treatment method for double segment thoracolumbar fracture with neurological injury.
ObjectiveTo study the effects of astaxanthin on the apoptosis after spinal cord injury in rats.MethodsOne hundred and forty-four healthy adult Sprague Dawley rats were divided into experimental group, control group, and sham group according to the random number table (n=48). In the control group and the experimental group, the modified Allen’s method was used to make the spinal cord injury model; in the sham group, only the lamina was cut without damaging the spinal cord. At immediate after operation, the rats in the experimental group were given intragastric administration of astaxanthin (75 mg/kg) twice a day; and the rats in the control group and the sham group were given equal amount of olive oil by gavage twice a day. BBB score was used to assess the motor function at 1 day and 1, 2, 3, and 4 weeks after operation. The malondialdehyde (MDA) content was determined by the thiobarbituric acid method at 24 hours after operation; and the activity of superoxide dismutase (SOD) was determined by the xanthine oxidase method. Apoptosis index (AI) was determined by TUNEL method at 6, 24, and 48 hours after operation. At 48 hours after operation, the water content of spinal cord was measured by dry-wet weight method, the lesion ratio of spinal cord was calculated, the ultrastructure of the spinal cord was observed by transmission electron microscopy, and ultrastructure scoring was performed using the Kaptanoglu score method.ResultsThe BBB score in the control group and the experimental group was significantly lower than that in the sham group at each postoperative time point (P<0.05); and the BBB score in the experimental group were significantly higher than that in the control group at 1-4 weeks postoperatively (P<0.05). The MDA content in the control group and the experimental group was significantly higher than that in the sham group at 24 hours after operation, and in the experimental group was significantly lower than in the control group (P<0.05). The SOD activity in the control group and the experimental group was significantly lower than that in the sham group, and in the experimental group was significantly higher than in the control group (P<0.05). At each time point postoperatively, the AI in the control group and the experimental group was significantly higher than that in the sham group, and in the experimental group was significantly lower than in the control group (P<0.05). At 48 hours after operation, the water content of spinal cord, the lesion ratio of spinal cord, and the ultrastructure score in the control group and the experimental group were significantly higher than those in the sham group, and in the experimental group were significantly lower than in the control group (P<0.05).ConclusionAstaxanthin can inhibit the lipid peroxidation, reduce the apoptosis, reduce the spinal cord edema, reduce the spinal cord lesion, reduce the histopathological damage after spinal cord injury, and improve the motor function of rats with spinal cord injury, and protect the spinal cord tissue, showing an obvious neuroprotective effect.
Objective To develop a tractive spinal cord injury model in rats with a novel spinal distractor so as to supply the rel iable animal model for researching the pathological mechanism and rehabil itation treatment of tractive spinal cordinjury. Methods A novel spinal distractor was prepared based on previous study. Sixty adult Sprague Dawley rats (weighing 250-300 g) were randomly divided into 5 groups, 12 rats in each group. T12-L3 spinal structures in the rear area were exposed and then T13-L2 spinal cords were revealed via dual laminectomy and kept integrity. In group A, a novel spinal distractor was placed without distraction; in groups B, C, D, and E, the T12-L3 spines were tracted with a novel spinal distractor which put on transverses process of T12-L3 vertebrae. During the tractive period, the somatosensory evoked potential (SEP) was used to monitor spinal cord function. The SEP ampl itudes descended 50% and kept distracting for 5 minutes in group B and for 10 minutes in group C, and descended 70% and kept distracting for 5 minutes in group D and for 10 minutes in group E, respectively to establ ish the tractive spinal cord injury model of T11-L2. The improved combine behavioral score (ICBS) was recorded at 1 and 7 days after injury in 6 rats of each group. The T13-L2 spinal tissue specimens were harvested for the morphological observation by HE and Nissl’s staining and for neurons counting. Results In group A, the ICBS score was 0 at 1 and 7 days after operation, showing significant difference when compared with the scores of the other groups (P lt; 0.05). The ICBS scores of groups D and E were significantly higher than those of groups B and C (P lt; 0.05). Edema and hemorrhage were observed in spinal cord surface and normal morphological structures were destroyed at different extent in groups B, C, D, and E at 1 day. There were adherence and congestion between spinal cord surface and peripheral issue without luster at 7 days, and dura depression was observed at the injury section, especially in group E. Necrosis and dissolution occurred in some neurons, and Nissl body structure dissolved or disappeared in groups B, C, D, and E. The neuron counting gradually decreased in accordance with the aggravation of injury in groups B, C, D, and E, showing significant difference when compared with group A (P lt; 0.05). Significant differences in neuron counting were found among groups B, C, D, and E (P lt; 0.05). Conclusion The tractive spinal cord injury model in rats can be successfully establ ished with novel spinal distractor, and the model establ ished by SEP ampl itude descending 70% and keeping distracting for 10 minutes is more suitable for study in tractive spinal cord injury.
ObjectiveTo evaluate the effect of the combination of collagen scaffold and brain-derived neurotrophic factor (BDNF) on the repair of transected spinal cord injury in rats.MethodsThirty-two Sprague-Dawley rats were randomly divided into 4 groups: group A (sham operation group), T9, T10 segments of the spinal cord was only exposed; group B, 4-mm T9, T10 segments of the spinal cord were resected; group C, 4-mm T9, T10 segments of the spinal cord were resected and linear ordered collagen scaffolds (LOCS) with corresponding length was transplanted into lesion site; group D, 4-mm T9, T10 segments of the spinal cord were resected and LOCS with collagen binding domain (CBD)-BDNF was transplanted into lesion site. During 3 months after operation, Basso-Beattie-Bresnahan (BBB) locomotor score assessment was performed for each rat once a week. At 3 months after operation, electrophysiological test of motor evoked potential (MEP) was performed for rats in each group. Subsequently, retrograde tracing was performed for each rat by injection of fluorogold (FG) at the L2 spinal cord below the injury level. One week later, brains and spinal cord tissues of rats were collected. Morphological observation was performed to spinal cord tissues after dehydration. The thoracic spinal cords including lesion area were collected and sliced horizontally. Thoracic spinal cords 1 cm above lesion area and lumbar spinal cords 1 cm below lesion area were collected and sliced coronally. Coronal spinal cord tissue sections were observed by the laser confocal scanning microscope and calculated the integral absorbance (IA) value of FG-positive cells. Horizontal tissue sections of thoracic spinal cord underwent immunofluorescence staining to observe the building of transected spinal cord injury model, axonal regeneration in damaged area, and synapse formation of regenerated axons.ResultsDuring 3 months after operation, the BBB scores of groups B, C, and D were significantly lower than those of group A (P<0.05). The BBB scores of group D at 2-12 weeks after operation were significantly higher than those of groups B and C (P<0.05). Electrophysiological tests revealed that there was no MEP in group B; the latencies of MEP in groups C and D were significantly longer than that in group A (P<0.05), and in group C than in group D (P<0.05). Morphological observation of spinal cord tissues showed that the injured area of the spinal cord in group B extended to both two ends, and the lesion site was severely damaged. The morphologies of spinal cord tissues in groups C and D recovered well, and the morphology in group D was closer to normal tissue. Results of retrograde tracing showed that the gray matters of lumbar spinal cords below the lesion area in each group were filled with FG-positive cells; in thoracic spinal cords above lesion sites, theIA value of FG-positive cells in coronal section of spinal cord in group A was significantly larger than those in groups B, C, and D (P<0.05), and in groups C and D than in group B (P<0.05), but no significant difference was found between groups C and D (P>0.05). Immunofluorescence staining results of spinal cord tissue sections selected from dorsal to ventral spinal cord showed transected injured areas of spinal cords which were significantly different from normal tissues. The numbers of NF-positive axons in lesion center of group A were significantly larger than those of groups B, C, and D (P<0.05), and in groups C and D than in group B (P<0.05), and in group D than in group C (P<0.05).ConclusionThe combined therapeutic approach containing LOCS and CBD-BDNF can promote axonal regeneration and recovery of hind limb motor function after transected spinal cord injury in rats.
ObjectiveTo explore the feasibility and mechanism of inhibiting miR-429 to improve the permeability of the blood spinal cord barrier (BSCB) in vitro, and provide a new gene therapy target for enhancing the spinal cord microenvironment.MethodsFirst, the immortalized human brain microvascular endothelial cell line (hCMEC/D3) was transfected with the anti-miR-429 antagonist (antagomiR-429) and its negative control (antagomiR-429-NC), respectively. The miR-429 expression of hCMEC/D3 cells was observed by fluorescence microscopy and real-time fluorescence quantitative PCR to verify the transfection efficiency of antagomiR-429. Then the effect of miR-429 on BSCB permeability was observed in vitro. The experiment was divided into 4 groups. The blank control group (group A) was constructed of normal hCMEC/D3 cells and Ha-sc cells to prepare the BSCB model, the hypoxia-induced group (group B), the hypoxia-induced+antagomiR-429-NC group (group C), and the hypoxia-induced+antagomiR-429 group (group D) were constructed of normal, antagomiR-429-NC transfected, and antagomiR-429 transfected hCMEC/D3 cells and Ha-sc cells to prepare the BSCB models and hypoxia treatment for 12 hours. The permeability of BSCB in vitro was measured by horseradish peroxidase (HRP) permeability. Real-time fluorescence quantitative PCR, Western blot, and immunofluorescence staining were used to observe the expressions of ZO-1, Occludin, and Claudin-5.ResultsThe antagomiR-429 and antagomiR-429-NC were successfully transfected into hCMEC/D3 cells under a fluorescence microscope, and the transfection efficiency was about 90%. Real-time fluorescence quantitative PCR results showed that the relative expression of miR-429 in antagomiR-429 group was 0.109±0.013, which was significantly lower than that of antagomiR-429-NC group (0.956±0.004, P<0.05). HRP permeability measurement, real-time fluorescence quantitative PCR, and Western blot results showed that the HRP permeability of groups B and C were significantly higher than those of groups A and D (P<0.05), and the relative expressions of ZO-1, Occludin, and Claudin-5 proteins and mRNAs were significantly lower in groups B and C than in groups A and D (P<0.05) and in group D than in group A (P<0.05); there was no significant difference between groups B and C (P>0.05). Immunofluorescence staining showed that the immunofluorescence of ZO-1, Occudin, and Claudin-5 at the cell membrane boundary in group D were stronger than those in groups B and C, but not as strong as that in group A.ConclusionInhibition of miR-429 expression can promote the expressions of ZO-1, Occludin, and Claudin-5 proteins in microvascular endothelial cells, thereby improving the increased permeability of BSCB due to hypoxia.
Spinal cord injury (SCI) is a complex pathological process. Based on the encouraging results of preclinical experiments, some stem cell therapies have been translated into clinical practice. Mesenchymal stem cells (MSCs) have become one of the most important seed cells in the treatment of SCI due to their abundant sources, strong proliferation ability and low immunogenicity. However, the survival rate of MSCs transplanted to spinal cord injury is rather low, which hinders its further clinical application. In recent years, hydrogel materials have been widely used in tissue engineering because of their good biocompatibility and biodegradability. The treatment strategy of hydrogel combined with MSCs has made some progress in SCI repair. This review discusses the significance and the existing problems of MSCs in the repair of SCI. It also describes the research progress of hydrogel combined with MSCs in repairing SCI, and prospects its application in clinical research, aiming at providing reference and new ideas for future SCI treatment.
In order to investigate the clinical significance of electron-neurogram for evaluating the degree and prognosis of acute traumatic cervical spinal cord injury without fracture or dislocation, electron-neurogram and sensory evoked potential (SEP) of the upper limbs in 4 such cases were recorded from the 3rd to 30th day after the injury. The results showed SEP and MEP could be obtained from every nerve in both upper limbs, and continous monitoring of SEP and MEP could provide valuable data to judge the degree and prognosis of the injury in spinal cord.
Objective To investigate the effect of quantitative semi-transected blade on the improvement of spinal cord semi-transected and lump defect model. Methods Forty-eight male Sprague Dawley rats (weighing 220-250 g) were divided into the experimental group (n=24) and control group (n=24). The spinal cord semi-transected and lump defect model was made by self-made quantitative semi-transected blade in the experimental group, and by ophthalmic scalpel in the controlgroup. Then, the complications were observed; the electrophysiological results were detected before modeling and at 21 days after modeling; the histological changes at margin of lump defect were observed at 6 hours, 5 days, and 28 days; Basso, Beattie, and Bresnahan (BBB) scores were detected at 1, 3, 5, 7, 14, 21, 28, 35, 42, 56, and 84 days after modeling. Results There was significant difference in the mortality between the experimental group (0) and the control group (26.67%) (P=0.028). Electrophysiological examination: there was no significant difference in latency and ampl itude of motor evoked potentials (MEP) and sensory evoked potentials (SEP) between 2 groups at preoperation (P gt; 0.05); at 21 days after operation, latencies of MEP and SEP increased and the amplitude decreased in the control group, showing significant differences when compared with those in the experimental group and the preoperative values (P lt; 0.05), but no significant difference was seen between preoperation and postoperation in the experimental group (P gt; 0.05). Histological examination: in the control group, small hematoma could be observed at normal side at 6 hours after modeling, increased spaces of spinal tissue and perineural invasion were observed at 5 days, and small cavity formed without normal motoneurons at 28 days in the margin of lump defect. In the experimental group, no small hematoma could be observed at 6 hours after modeling, no inreversible injury of neuron and small cavity were observed at 5 days, and normal motoneurons were observed without small cavity at 28 days in the margin of lump defect.BBB scores: except the scores between experimental group and control group at affected side (P gt; 0.05), there were significant differences between groups, and between normal side and affected side for intragroup (P lt; 0.05). Conclusion Semi-transected and lump defect model could be set up successfully by self-made quantitate semi-transected blade, procedure is repetitive and the model is stable. This model is an ideal model for semi-transected spinal cord injury.
Objective Aminoguanidine (AG) can reduce brain edema and increase the recovery of neuron functions in surgical brain injury and stroke. To investigate the effect of AG on spinal cord injury (SCI) in rats and its mechanism. Methods A total of 150 adult male Sprague Dawley rats (weighing, 230-255 g) were divided into control group (group A, 25 rats without treatment), the sham-operated group (group B, 25 rats undergoing laminectomy), SCI group (group C, 25 SCI rats with injection of 5%DMSO), SCI + AG groups (groups D, E, and F, 25 SCI rats and AG injection of 75, 150, and 300 mg/kg, respectively). The optimal dosage of AG was screened by dry-wet weight method with the percentage of water content at 0, 12, 24, and 48 hours after injury. The blood-spinal cord barriar permeability was further detected by Evans blue (EB) method, aquaporins 4 (AQP4) mRNA expression by RT-PCR, AQP4 protein expression by immunohistochemistry and Western blot. Results AG injection at dosage of 150 mg/kg can significantly reduce edema of spinal cords at 12, 24, and 48 hours after SCI (P lt; 0.05), so 150 mg/kg was the optimal dosage. The EB content in group E was significantly lower than that in group C at 12, 24, and 48 hours after SCI, and the permeability of blood-spinal cord barrier was significantly decreased compared with group C (P lt; 0.05). The AQP4 mRNA expressions in groups B and E were significantly lower than that in group C at 12, 24, and 48 hours after SCI (P lt; 0.05). AQP4 protein expressions in groups B and E were significantly lower than that in group C at 24 and 48 hours after SCI (P lt; 0.05) by Western blot. Immunohistochemical staining revealed that AQP4 protein expression in group C was significantly higher than that in groups B and E (P lt; 0.05) at 48 hours after SCI, but no significant difference was found between group B and group E (P gt; 0.05). Conclusion AG injection at dosage of 150 mg/kg can induce spinal cord edema and injury in rats, which could be correlated with the down-regulation of AQP4 expression.
ObjectiveTo systematically profile and characterize the circular RNA (circRNA) and microRNA (miRNA) expression pattern in the lesion epicenter of spinal tissues after traumatic spinal cord injury (TSCI) and predict the structure and potential functions of the regulatory network.MethodsForty-eight adult male C57BL/6 mice (weighing, 18-22 g) were randomly divided into the TSCI (n=24) and sham (n=24) groups. Mice in the TSCI group underwent T8-10 vertebral laminectomy and Allen’s weight-drop spinal cord injury. Mice in the sham group underwent the same laminectomy without TSCI. The spinal tissues were harvested after 3 days. Some tissues were stained with HE staining to observe the structure. The others were used for sequencing. The RNA-Seq, gene ontology (GO) analysis, and circRNA-miRNA network analyses (TargetScan and miRanda) were used to profile the expression and regulation patterns of network of mice models after TSCI.ResultsHE staining showed the severe damage to the spinal cord in TSCI group compared with sham group. A total of 17 440 circRNAs and 1 228 miRNAs were identified. The host gene of significant differentially expressed circRNA enriched in the cytoplasm, associated with positive regulation of transcription and protein phosphorylation. mmu-miR-21-5p was the most significant differentially expressed miRNA after TSCI, and circRNA6730 was predicted to be its targeted circRNA. Then a potential regulatory circRNA-miRNA network was constructed.ConclusionThe significant differentially expressed circRNAs and miRNAs may play important roles after TSCI. A targeted interaction network with mmu-miR-21-5p at the core of circRNA6730 could provide basis of pathophysiological mechanism, as well as help guide therapeutic strategies for TSCI.