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 To investigate the effects of removing microglia from spinal cord on nerve repair and functional recovery after spinal cord injury (SCI) in mice. MethodsThirty-nine 6-week-old female C57BL/6 mice were randomly divided into control group (n=12), SCI group (n=12), and PLX3397+SCI group (n=15). The PLX3397+SCI group received continuous feeding of PLX3397, a colony-stimulating factor 1 receptor inhibitor, while the other two groups were fed a standard diet. After 14 days, both the SCI group and the PLX3397+SCI group were tested for ionized calcium binding adapter molecule 1 (Iba1) to confirm that the PLX3397+SCI group had completely depleted the spinal cord microglia. The SCI model was then prepared by clamping the spinal cord in both the SCI group and the PLX3397+SCI group, while the control group underwent laminectomy. Preoperatively and at 1, 3, 7, 14, 21, and 28 days postoperatively, the Basso Mouse Scale (BMS) was used to assess the hind limb function of mice in each group. At 28 days, a footprint test was conducted to observe the gait of the mice. After SCI, spinal cord tissue from the injury site was taken, and Iba1 immunofluorescence staining was performed at 7 days to observe the aggregation and proliferation of microglia in the spinal cord. HE staining was used to observe the formation of glial scars at the injury site at 28 days; glial fibrillary acidic protein (GFAP) immunofluorescence staining was applied to astrocytes to assess the extent of the injured area; neuronal nuclei antigen (NeuN) immunofluorescence staining was used to evaluate neuronal survival. And 5-hydroxytryptamine (5-HT) immunofluorescence staining was performed to assess axonal survival at 60 days. Results All mice survived until the end of the experiment. Immunofluorescence staining revealed that the microglia in the spinal cord of the PLX3397+SCI group decreased by more than 95% compared to the control group after 14 days of continuous feeding with PLX3397 (P<0.05). Compared to the control group, the BMS scores in the PLX3397+SCI group and the SCI group significantly decreased at different time points after SCI (P<0.05). Moreover, the PLX3397+SCI group showed a further decrease in BMS scores compared to the SCI group, and exhibited a dragging gait. The differences between the two groups were significant at 14, 21, and 28 days (P<0.05). HE staining at 28 days revealed that the SCI group had formed a well-defined and dense gliotic scar, while the PLX3397+SCI group also developed a gliotic scar, but with a more blurred and loose boundary. Immunofluorescence staining revealed that the number of microglia near the injury center at 7 days increased in the SCI group than in the control group, but the difference between groups was not significant (P>0.05). In contrast, the PLX3397+SCI group showed a significant reduction in microglia compared to both the control and SCI groups (P<0.05). At 28 days after SCI, the area of spinal cord injury in the PLX3397+SCI group was significantly larger than that in SCI group (P<0.05); the surviving neurons significantly reduced compared with the control group and SCI group (P<0.05). The axonal necrosis and retraction at 60 days after SCI were more obvious. ConclusionThe removal of microglia in the spinal cord aggravate the tissue damage after SCI and affecte the recovery of motor function in mice, suggesting that microglia played a neuroprotective role in SCI.
Objective To investigate the expression pattern of hypoxia-inducible factor 1α (HIF-1α) in experimental secondary spinal cord injury (SSCI) in rats and its potential effects on SSCI. Methods A total of 66 SD rats (female or male) with weight (250 ± 20) g were randomly divided into 3 groups: normal control group (group A, n=6), pseudo injury group (group B, n=6), and spinal cord injury (SCI) group (group C, n=54). In group A, no treatment was given as normal control. In groupB, only laminectomy was appl ied. In group C, laminectomy was appl ied and static compression model of SCI was built at T10 level. The expression of HIF-1α was measured with HE and immunohistochemical staining in groups A, B (1 hour after pseudo injury), and C (1, 3, 6, 12 hours and 1, 2, 3, 7, 14 days after SCI). Results All rats survived to the end of the experiment. HE staining showed that the spinal tissue of groups A and B were dense and the nucleus were round and big with l ight staining and clear nucleolus. The injured neuron at 1-12 hours after SCI of group C presented pyknosis and deep eosin staining. The swelling axon with bubbles and the disintegrated and disorganized medullary sheath in white matter appeared at 1-3 days after SCI. The hyperplasia of gl ial cells were obvious and gray matter cells were broken and apoptosis with cavities in injured spinal segment was observed at 7 and 14 days after SCI. Immunohistochemical staining showed that HIF-1α was poorly expressed in group A and increased a l ittle in group B. The positive expression in group C increased at 3 hours after SCI, which was found in spinal cord anterior horn neurons and a small amount of gangl ion cells. It reached peak at 1 day, maintained at a high level during 1-3 days and then decl ined. At 14 days, it appeared only in a small amount of gangl ion cells of white matter. There was no significant difference in the number of HIF-1α positive cells between groups A and B (t=1.325, P=0.137). The number of HIF-1α positive cells at each time point in group C was more than those in groups A and B (P lt; 0.05), and there were significant differences between all time points in group C (P lt; 0.05). Conclusion The expression of HIF-1α increases after SCI, it is related to the ischemia hypoxia after SSCI, and the expression pattern was correlated with the injury time.
ObjectiveTo explore the effectiveness of functional reconstruction of hand grasp and pinch by tendon transfers in patients with cervical spinal cord injury.MethodsBetween July 2013 and January 2016, tendon transfer surgery were performed in 21 patients (41 hands) with cervical spinal injury that motion level was located at C6 to reconstruct hand grasp and pinch function. There were 18 males and 3 females with a mean age of 42.3 years (range, 17-65 years). Nineteen patients were with complete spinal cord injury [American Spinal Injury Association (ASIA) grading A], 1 patient was with central cord syndrome whose bilateral hands were completely paralyzed and lower limbs were normal (ASIA grading D), and 1 patient was with cervical spondylotic myelopathy (AISA grading D). The time from injury to hospitalization was 12-22 months (mean, 16.8 months). According to the International classification of surgery of the hand in tetraplegia (ICSHT), there were 6 cases of grade O3, 10 of grade O4, 3 of grade OCu5, and 2 of grade O5. The surgery was divided into two stages with an interval of 6-11 months. At the first stage, grip function was reconstructed in all patients by transfering the extensor carpi radialis longus from radialis side to palmar side through subcutaneous tunnel, and braided and sutured with the flexor pollicis longus and flexor digitorum profundus. At the second stage, the lateral pinch function of the thumb and index finger was reconstructed by braiding and suturing the radial half of the extensor carpi ulnaris (the patients graded as ICSHT O3) or pronator tere (the patients graded above ICSHT O3) with extensor pollicis longus and abductor pollicis longus. The grasp force, the thumb and index finger lateral pinch force, and the maximum fingertips distance between the thumb and index finger were measured at preoperation and at different time points after operation. The modified Lamb and Chan questionnaire, based upon the activities of daily living, was used to evaluate the hand function of all patients at 6 months after sencond stage surgery.ResultsThere was 1 patient with elbow skin lesion, 1 patient with wrist stiffness; both of them recovered after corresponding treatment. All the 21 patients were followed up 15-32 months (mean, 19.6 months) without wound infection, tendon adhesion, tendon rupture, and other complications. The grasp forces of all patients were significantly improved at 4 weeks, 3 months, 6 months, and 1 year after the first stage surgery when compared with preoperative value (P<0.05); and no significant difference was found between different time points after operation (P>0.05). The thumb and index finger lateral pinch force and the maximum fingertips distance between the thumb and index finger of all patients were also significantly improved at 4 weeks, 3 months, 6 months, and 1 year after the second stage surgery when compared with preoperative values (P<0.05); and no significant difference was found between different time points after operation (P>0.05). And there was no significant difference of above indexes between the patients graded as ICSHT O3 and above ICSHT O3 (P>0.05). The functional outcome was good in 19 cases, fair in 1 case, and poor in 1 case according to modified Lamb and Chan questionnaire at 6 months after second stage surgery.ConclusionTendon transfer can significantly improve the hand function and the quality of life of the patients with complete cervical spinal cord 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.
ObjectiveTo investigate the effect of saikosaponin a (SSa) on the levels of immune inflammation in rats with acute spinal cord injury and its possible mechanism.MethodsSeventy-two Sprague Dawley rats (weighing, 220-250 g) were randomly divided into sham operation group (group A), spinal cord injury group (group B), and SSa treatment group (group C) respectively, 24 rats in each group. The spinal cord injury model was induced by using the Allen’s method in groups B and C; the spinous process and vertebral plate at both sides were cut off by lamina excision to expose the spinal cord in group A. The rats were given intraperitoneal injection of 10 mg/kg SSa in group C and equal volume of normal saline in group B at immediate after injury. The spinal cord tissue was harvested from 18 rats of each group at 24 hours after operation to measure the levels of tumor necrosis factor α (TNF-α) and interleukin 6 (IL-6) by ELISA, to detect the expressions of nuclear factor κB (NF-κB) P65, NF-κB P-P65, and aquaporin 4 (AQP4) by Western blot and to observe the morphology of spinal cord by HE staining. The motor function of the lower limbs was evaluated by BBB score and tiltboard experiment in 6 rats at 1, 3, 7, 14, 21, and 28 days after injury.ResultsThe BBB score and tiltboard experiment maximum angle were significantly higher in group A than groups B and C at each time point (P<0.05) and in group C than group B at 14, 21, and 28 days after operation (P<0.05). ELISA test showed that the concentrations of TNF-α and IL-6 were significantly lower in group A than groups B and C, and in group C than group B (P<0.05). Western blot results showed that the protein expression levels of NF-κB P65, NF-κB P-P65, and AQP4 were significantly lower in group A than groups B and C, and in group C than group B (P<0.05). HE staining demonstrated normal neurons of the spinal cord and no obvious lesion in group A; neuronal cells were observed in the injured area of group B, with hemorrhage, neutrophil infiltration, and nerve cell edema in the injured area; the neuronal cells were visible in the spinal cord of group C, with microglia mild hyperplasia, and the pathological changes were improved when compared with group B.ConclusionSSa has neuroprotective effects on acute spinal cord injury in rats by inhibiting NF-κB signaling pathway and AQP4 protein expression and reducing inflammation response and edema.
Objective To investigate tissue engineered spinal cord which was constructed of bone marrow mesenchymal stem cells (BMSCs) seeded on the chitosan-alginate scaffolds bridging the both stumps of hemi-transection spinal cord injury (SCI) in rats to repair the acute SCI. Methods BMSCs were separated and cultured from adult male SD rat. Chitosan-alginate scaffold was produced via freeze drying, of which the structure was observed by scanning electron microscope (SEM) and the toxicity was determined through leaching l iquor test. Tissue engineered spinal cord was constructed by seeding second passage BMSCs on the chitosan-alginate scaffolds (1 × 106/mL) in vitro and its biocompatibil ity was observed under SEM at 1, 3, and 5 days. Moreover, 40 adult female SD rats were made SCI models by hemi-transecting at T9 level, and were randomly divided into 4 groups (each group, n=10). Tissue engineered spinal cord or chitosan-alginate scaffolds or BMSCs were implanted in groups A, B, and C, respectively. Group D was blank control whose spinal dura mater was sutured directly. After 1, 2, 4, and 6 weeks of surgery, the functional recovery of the hindl imbs was evaluated by the Basso-Beattie-Bresnahan (BBB) locomotor rating score. Other indexes were tested by wheat germ agglutinin-horseradish peroxidase (WGA-HRP) retrograde tracing, HE staining and immunofluorescence staining after 6 weeks of surgery. Results Chitosan-alginate scaffold showed three-dimensional porous sponge structure under SEM. The cells adhered to and grew on the surface of scaffold, arranging in a directional manner after 3 days of co-culture. The cytotoxicity of chitosan-alginate scaffold was in grade 0-1. At 2, 4, and 6 weeks after operation, the BBB score was higher in group A than in other groups and was lower in group D than in other groups; showing significant differences (P lt; 0.05). At 4 and 6 weeks, the BBB score was higher in group B than in group C (P lt; 0.05). After 6 weeks of operation, WGA-HRP retrograde tracing indicated that there was no regenerated nerve fiber through the both stumps of SCI in each group. HE and immunofluorescence staining revealed that host spinal cord and tissue engineering spinal cord l inked much compactly, no scar tissue grew, and a large number of neurofilament 200 (NF-200) positive fibers and neuron specitic enolase (NSE) positive cells were detected in the lesioned area in group A. In group B, a small quantity of scar tissue intruded into non-degradative chitosan-alginate scaffold at the lesion area edge, and a few of NSE flourescence or NF-200 flourescence was observed at the junctional zone. The both stumps of SCI in group C or group D were filled with a large number of scar tissue, and NSE positive cells or NF-200 positive cells were not detected. Otherwise, there were obviously porosis at the SCI of group D. Conclusion The tissue engineered spinal cord constructed by multi-channel chitosan-alginate bioscaffolds and BMSCs would repair the acute SCI of rat. It would be widely appl ied as the matrix material in the future.
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.
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.
ObjectiveTo explore the practice of the evidence-based treatment strategy for cervical spinal cord injury. MethodsOne patient with cervical spinal cord injury was admitted to our hospital on January 3, 2013. We obtained medical evidences by searching databases and regulated the best treatment after evaluating the patient's comprehensive conditions. And then, the whole treatment strategy was fully implemented. Finally, the consequent results were evaluated. ResultsThe evidence-based medicine showed that the therapeutic targets were to save the residual function, prevent complications, and promote the recovery of neural function. Based on the real-time conditions of patient, we developed and practiced the evidence-based comprehensive rehabilitation programs, including absolute rest in bed, high-dose steroids, neurotrophic drugs, Chinese medicine rehabilitation and prevention of complications. After a follow-up of half a year, the patient obtained a good curative effect. The patient was saved from paralyzing. Moreover, the patient restored the capacity of standing, walking and a certain level of self-care ability. ConclusionFor the cervical spinal cord injury, treatment decision based on evidence-based medicine is more scientific, and it can ensure maximum benefit for the patients. Therefore, it is worthy of popularizing.