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 explore the therapeutic effect of basic fibroblast growth factor (bFGF) on spinal cord injury (SCI) in rats and the influence of Notch/signal transducer and activator of transcription 3 (STAT3) signaling pathway. Methods A total of 40 10-week-old male Sprague Dawley (SD) rats were selected to establish T10-segment SCI model by a free falling object. Among them, 32 successful models were randomly divided into model group and bFGF group, with 16 in each group. Another 16 SD rats were selected as sham-operation group, with only T10 processes, dura mater, and spinal cord exposed. After modeling, the rats in bFGF group were intraperitoneally injected with 100 μg/kg bFGF (once a day for 28 days), and the rats in model group and sham-operation group were injected with normal saline in the same way. The survival of rats in each group were observed after modeling. Basso-Beattie-Bresnahan (BBB) scores were performed before modeling and at immediate, 14 days, and 28 days after modeling to evaluate the functional recovery of hind limbs. Then, the spinal cord tissue at the site of injury was taken at 28 days and stained with HE, Nissl, and propidium iodide (PI) to observe the pathological changes, neuronal survival (number of Nissl bodies) and apoptosis (number of PI red stained cells) of the spinal cord tissue; immunohistochemical staining and ELISA were used to detect the levels of astrocyte activation markers [glial fibrillary acidic protein (GFAP)] and inflammatory factors [interleukin 1β (IL-1β), tumor necrosis factor α (TNF-α), interferon γ (IFN-γ)] in tissues, respectively. Western blot was used to detect the expressions of Notch/STAT3 signaling pathway related proteins [Notch, STAT3, phosphoryl-STAT3 (p-STAT3), bone morphogenetic protein 2 (BMP-2)] in tissues. Results All rats survived until the experiment was completed. At immediate after modeling, the BBB scores in model group and bFGF group significantly decreased when compared to sham-operation group (P<0.05). At 14 and 28 days after modeling, the BBB scores in model group significantly decreased when compared to sham-operation group (P<0.05); the bFGF group showed an increase compared to model group (P<0.05). Compared with before modeling, the BBB scores of model group and bFGF group decreased at immediate after modeling, and gradually increased at 14 and 28 days, the differences between different time points were significant (P<0.05). The structure of spinal cord tissue in sham-operation group was normal; in model group, there were more necrotic lesions in the spinal cord tissue and fewer Nissl bodies with normal structures; the number of necrotic lesions in the spinal cord tissue of the bFGF group significantly reduced compared to the model group, and some normally structured Nissl bodies were visible. Compared with sham-operation group, the number of Nissl bodies in spinal cord tissue significantly decreased, the number of PI red stained cells, GFAP, IL-1β, TNF-α, IFN-γ, Notch, p-STAT3 /STAT3, BMP-2 protein expression levels significantly increased in model group (P<0.05). The above indexes in bFGF group significantly improved when compared with model group (P<0.05). Conclusion bFGF can improve motor function and pathological injury repair of spinal cord tissue in SCI rats, improve neuronal survival, and inhibit neuronal apoptosis, excessive activation of astrocytes in spinal cord tissue and inflammatory response, the mechanism of which may be related to the decreased activity of Notch/STAT3 signaling pathway.
Objective To evaluate the feasibility, safety, and early effectiveness of percutaneous endoscopic thoracic spine surgery via the trench technique for ventral decompression in central calcified thoracic disc herniation (CCTDH) and thoracic ossification of the posterior longitudinal ligament (T-OPLL). MethodsSeven patients with single-segment CCTDH or T-OPLL admitted between June 2017 and May 2020 and meeting the selection criteria were retrospectively analyzed. There were 3 males and 4 females with an average age of 51.7 years ranging from 41 to 62 years. There were 2 patients with T-OPLL (T1, 2 in 2 cases) and 5 patients with CCTDH (T1, 2 in 1 case, T7, 8 in 1 case, T10, 11 in 2 cases, T11, 12 in 1 case). Five patients with thoracic axial pain and intercostal neuralgia had a preoperative visual analogue scale (VAS) score of 6.0 (5.0, 6.5), and 7 patients had a preoperative Japanese Orthopaedic Association (JOA) score of 21 (21.0, 22.0). Transforaminal approach was used in 4 cases and transpedicular approach in 3 cases. Ventral decompression of thoracic spinal cord was performed by thoracic endoscopy combined with trench technique. The operation time, intraoperative blood loss, postoperative hospital stay, and postoperative complications were recorded. Thoracic spine CT and MRI were performed preoperatively and postoperatively to evaluate the surgical decompression, VAS score was used to evaluate the pain of thoracic back and lower limbs, and JOA score was used to evaluate the functional recovery. Modified MacNab criteria was used to evaluate the effectiveness. ResultsAll surgeries were successfully completed. The operation time ranged from 60 to 100 minutes, with an average of 80.4 minutes; the intraoperative blood loss ranged from 40 to 75 mL, with an average of 57.1 mL; the postoperative hospital stay ranged from 4 to 7 days, with an average of 5.4 days. CT and MRI examinations indicated that the decompression was adequate. All 7 patients were followed up 3-22 months, with an average of 13.3 months. One case developed postoperative wound infection, and 1 case developed pneumonia; the remaining patients did not have any complications such as wound infection or cerebrospinal fluid leakage. Five patients with thoracic axial pain and intercostal neuralgia had VAS scores of 2.0 (1.5, 2.5) at 1 day after operation and 2.0 (1.0, 2.0) at last follow-up, both of which were significantly lower than the preoperative scores (P<0.05). At 1 day after operation, the JOA scores for all 7 patients were 22.0 (21.0, 24.0), which showed no significant difference compared to the preoperative score (P>0.05); however, at last follow-up, the score improved to 24.0 (24.0, 26.0), which was significant compared to the preoperative scores (P<0.05). At last follow-up, the effectiveness was assessed using the modified MacNab criteria, the results were excellent in 2 cases, good in 3 cases, fair in 2 cases, and the excellent and good rate was 71.4%.ConclusionUsing the trench technique, percutaneous endoscopic thoracic spine surgery can achieve the ventral decompression in CCTDH and T-OPLL, providing a new approach for surgical treatment of CCTDH and T-OPLL.
Objective To explore the related factors of upper urinary tract deterioration (UUTD) in spinal cord injury patients using intermittent catheterization (IC-SCI) in the community. Methods Patients with spinal cord injury in the Chinese community were selected for investigation between August 3 and August 31, 2020. The included patients were divided into UUTD group and non-UUTD group. The basic information, intermittent catheterization practices, and urinary complications were compared between the two groups. Logistic regression was used to analyze the risk factors contributing to UUTD. Results A total of 431 patients were surveyed. Among them, there were 310 males and 121 females, 246 cases in the non-UUTD group and 185 cases in the UUTD group. There were statistically significant differences in the disease duration, gender, etiology, urinary incontinence, urinary tract infection, bladder calculi and nephrolithiasis between the two groups (P<0.05); there was no statistically significant difference in the other indicators between the two groups (P>0.05). The results of logistic regression analysis showed that urinary tract infection [odds ratio (OR)=3.229, 95% confidence interval (CI) (1.706, 6.110), P<0.001], nephrolithiasis [OR=4.846, 95%CI (2.617, 8.973), P<0.001], and urinary incontinence [OR=2.345, 95%CI (1.116, 4.925), P=0.024] were risk factors for UUTD. Conclusion Urinary tract infection, nephrolithiasis and urinary incontinence are independent risk factors for UUTD in community-based IC-SCI patients and deserve attention for preventive strategies.
ObjectiveTo review the definition and possible etiologies for C5 palsy. MethodsThe literature on C5 palsy at home and abroad in recent years was extensively reviewed, and the possible etiologies were analyzed based on clinical practice experience. ResultsThere are two main theories (nerve root tether and spinal cord injury) accounting for the occurrence of C5 palsy, but both have certain limitations. The former can not explain the occurrence of C5 palsy after anterior cervical spine surgery, and the latter can not explain that the clinical symptoms of C5 palsy is often the motor dysfunction of the upper limb muscles. Based on the previous reports, combining our clinical experience and research, we propose that the occurrence of C5 palsy is mainly due to the instrumental injury of anterior horn of cervical spinal cord during anterior cervical decompression. In addition, the C5 palsy following surgery via posterior approach may be related to the nerve root tether caused by the spinal cord drift after decompression. ConclusionIn view of the main cause of C5 palsy after cervical decompression, it is recommended to reduce the compression of the spinal cord by surgical instruments to reduce the risk of this complication.
Finite element analysis can be used to study the change of the structure and the interior field intensity of human and animal body organs and tissues with simulation experiment. We in our research used finite element analysis software to analyze and solve the spinal cord surface potential problems, and investigated the transmission features of signals generated by interneurons in spinal nerves which were related with body motion control and sensory processing. A three dimensional model of electrical source in rat spinal cord was built, and the influence on potential distribution on spinal cord surface caused by position changes of electrical source in transverse direction and dorsoventral direction were analyzed and calculated. We obtained the potential distribution curves of spinal cord surface and found that the potential distribution on spinal cord surface showed monotone. In addition, potentials of some registration points were smaller than that of registration points around.
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.
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.
OBJECTIVE Following the delayed repair of peripheral nerve injury, the cell number of anterior horn of the spinal cord and its ultrastructural changes, motorneuron and its electrophysiological changes were investigated. METHODS In 16 rabbits the common peroneal nerves of both sides being transected one year later were divided into four groups randomly: the degeneration group and regeneration of 1, 3 and 5 months groups. Another 4 rabbits were used for control. All transected common peroneal nerves underwent epineural suture except for the degeneration group the electrophysiological examination was carried out at 1, 3 and 5 months postoperatively. Retrograde labelling of the anterior horn cells was demonstrated and the cells were observed under light and electronmicroscope. RESULTS 1. The number of labelled anterior horn cell in the spinal cord was 45% of the normal population after denervation for one year (P lt; 0.01). The number of labelled cells increased steadily from 48% to 57% and 68% of normal values at 1, 3 and 5 months following delayed nerve repair (P lt; 0.01). 2. The ultrastructure of the anterior horn cells of the recover gradually after repair. 3. With the progress of regeneration the latency become shortened, the conduction velocity was increased, the amplitude of action potential was increased. CONCLUSION Following delayed repair of injury of peripheral nerve, the morphology of anterior horn cells of spinal cord and electrophysiological display all revealed evidence of regeneration, thus the late repair of injury of peripheral nerve was valid.
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.