组织工程的提出、建立和发展,为最终实现脊髓损伤的修复和真正意义上的结构、形态与功能重建开辟了新的途径。支架的生物活性、三维结构和表面微观结构,材料的降解性等众多因素都对细胞增殖,分化和组织形成有明显影响。组织工程的发展也将改变传统的医学模式,使得再生医学得以进一步发展,并最终用于疾病的治疗。
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 study the advance in the treatment of atonic bladder after spinal cord injury. Methods The rencent literature concerned was extensively reviewed and some methods of therapy for atonic bladder were introduced. Results No effective method of therapy was found for atonic bladder after spinal cord injury. When compared with clean intermittent catheterization, pharmacologic therapy, compressive micturition and detrusor function reconstruction, the establishment of an artificial bladder reflex arc may have a potential of controllable micturition. Conclusion To establish an artificial bladder reflex may provide an update of current therapeutic concepts for atonic bladder after spinalcord injury.
Objective To investigate the synergistic effect of a combination of grafted olfactory ensheathing cells (OECs) from the olfactory bulbs and intrathecal injection of vascular endothel ial growth factor (VEGF) on repairing spinal cord injury, and to explore the neuroprotection on both neurons and nerve fibers. Methods OECs from neonatal rats were cultured, purified, and collected with 0.25% trypsin after 9 days. A total of 75 adult female Wistar rats (weighing 200-250 g) were randomly divided into 5 groups: group A was sham-surgery group receiving laminectomy; the spinal cord injury model was establ ished with weight-dropped apparatus in the rats of groups B, C, D, and E. Then group B was injected with 10 μL DMEM-F12 medium without serum at injury site on the 1 day and was intrathecally administrated with 10 μL sal ine solutiontwice a day during the following 1 week; group C was injected with 10 μL DMEM-F12 medium and 25 ng recombined ratVEGF165 (rrVEGF165); group D was injected with 10 μL DMEM-F12 medium containing 1 × 105 OECs and 10 μL sal ine solution; group E was injected with 10 μL DMEM-F12 medium containing 1 × 105 OECs and 25 ng rrVEGF165. The functional recovery of hindl imb was evaluated by the Basso-Beattie-Bresnahan (BBB) score at 1 day and each week from 1 to 8 weeks. The histological changes and the changes of ultrastructure were observed at 8 weeks after operation by HE and electron microscope, and the immunohistochemistry staining was used for p75 nerve growth factor receptor (p75NGFR), Caspase-3, and von Willebrand factor (vWF). Results The function of hindl imb recovered rapidly in group E; the BBB score reached the peak at 8 weeks, and it was significantly higher than those in other groups (P lt; 0.05). The histology and ultrastructure observation showed that nerve fibers and neurons were damaged seriously in group B, oderately in groups C and D, and sl ightly in group E. Numerous spared tissue between nerve stumps, fibers with regular myel ination, and neurons with l ittle vacuolar mitochondria were observed in group E. The immunohistochemistry staining revealed that Caspase-3 positive cells in groups B, C, D, and E were significantly more than that in group A (P lt; 0.05); more Caspase-3 positive cells were found in groups B and D than in groups C and E (P lt; 0.05), while no significant difference was found between groups C and E (P gt; 0.05). And more vessels per high field were examined in groups C and E than in groups A, B, and D (P lt; 0.05), while no significant difference was found between groups C and E (P gt; 0.05). The p75NGFR positive results showed the survival of OECs in groups D and E at 8 weeks after OECstransplantation. Conclusion Grafted OECs combined with intrathecal injection of VEGF has significant promotive effects on restoration of spinal cord injury in rats, can improve part function of nerve fibers, and shows neuroprotection on damaged cells and fibers, which have a synergistic effect.
Objective To explore the factors to affect severity of hyperextension injury of the cervical spinal cord (HEICSC). Methods Forty-five patients with HEICSC, 35 males and 10 females, aged 27-67 years old (mean 48.2 years old), were retrospectively analyzed. The disease course was 30 minutes to 16 days. According to modified Frankel grading, there were 6 cases of grade A, 8 cases of grade B, 16 cases of grade C and 15 cases of grade D. Spinal cord injuries (SCI) segments were determined according to SCI plane and high signal change (HSC) in spinal cord on MR images. The whole or large part of HSC segments were supposed to be main injured spinal cord segments (MISCSs) and the staccato or patchy HSC ones were supposed to be common injured spinal cord segments (CISCSs). When the external force acting on head or face suffered was larger, the force produced during high-speed movement or forehead and/or face had severe contused and/or) lacerated wound, the force was defined severe traumatic strength, whereas the reverse was true for sl ight traumatic strength. According to signal magnitude of the cervical discs on T2-weighted MR images, degeneration of cervical discs and cervical vertebras were classified into 5 grades: grade 0-4. Cervical spinal stenosis were graded to 5 grades according to the width of anterior or posterior cerebrospinal fluid layer to spinal cord on T2-weighted MR images and compressed degree of spinal cord on T1-weighted MR images. The influence of traumatic strength, cervical spinal degeneration or cervical spinal stenosis on SCI were explored. Results Among the 45 cases, 12 cases were caused by sl ight traumatic strength, 33 cases were caused by severe one. The cervical spinal cord was injuried more sl ightly and the patients were older in the sl ight traumatic strength cases than in the severe ones (P lt; 0.05). The number of MISCSs were 45 in 40 cases and the 25 segments were located at C3, 4 level. The number of CISCSs were 39 in 21 cases. All the cervical vertebraes of the 45 patients had degenerated. The most were in grade 3 in 22 patients and the severest degenerative segments were mostly located in C5,6 discs in 35 ones. The number of the MISCSs in different degenerative grades of discs was 0 in grade 0, 9 in grade 1, 20 in grade 2, 14 in grade 3, and 2 in grade 4. The ratios of the segment number of injuried spinal cord to the segment number of spinal stenosis in every grade of stenosis were 1/62 in grade 0, 2/11 in grade 1, 27/52 in grade 2, 33/33 in grade 3, 21/22 in grade 4. Conclusion Three main factors including the magnitude of traumatic strength, the degree of instabil ity of cervical vertebrae and the degree of cervical stenosis contribute to development and progress of HEICSC.
Thirty-five SD rats were divided into 3 groups, in which 5 rats were served as control. The other 2 groups, 15 rats in each received either NGF solution or normal saline. The injury at the level of T8 spinal segment of the rat in these two groups were made by dropping a weight of 10 g from a height 2.5 cm after a total laminectomly from T7-11 segments. A thin plastic tube was inserted into the subarachnoid space below the injured segments. NGF was introduced through the tube at intervals of 1, 2, 3, 4, 8, 12, 24, 48 hours in the NGF group, and normal saline in the normal saline group. At 4, 8, 24 hours following surgery, 5 rats in each group were sacrificed and the injured segments were resected for examination. The contents of water and calcium were measured by dry-wet method and atomic absorption spectroscopy. The result showed that total calcium and water contents in normal saline group were markly increased, however, the changes of these two parametere were not so prominent in NGF group. It was suggested that NGF play a role in protecting the spinal cord by maintaining the calcium level of the injured segment.
To summarize Notch, basic hel ix-loop-hel ix (bHLH) and Wnt gene signal transduction pathways in the process of differentiation and development of neural stem cells. Methods The l iterature on the gene signal transduction pathway in the process of differentiation and development of neural stem cells was searched and then summarized and analyzed. Results The formation of Nervous System resulted from common actions of multi-signal transduction pathways. There may exist a fixed threshold in the compl icated selective system among Notch, bHLH and Wnt gene signal transduction pathways. Conclusion At present, the specific gene signal transduction pathway of multi pl ication and differentiation of neural stem cells is still unclear.
目的：分析汶川地震致脊髓损伤患者的病情特点。方法：对35例地震致脊髓损伤患者进行回顾性调查。结果：地震造成的这35例脊髓损伤患者在性别、年龄无明显差异，完全性损伤占42.86%，不完全损伤占57.14%。主要致伤原因为压榨伤（68.57%）。骨折部位依次为腰椎（57.14%）、胸椎（28.57%）、颈椎（11.43%）。受伤时体位60%为屈曲位。31.43%的完全性损伤患者由非专业救援人员救出。结论：35例患者脊髓损伤程度普遍较重，主要是与地震当时巨大冲击力有关，也与受灾现场救援条件严重受限，错过最佳治疗时机有关。现场的急救、救援方式对患者的伤情和预后有重要影响，因此需要大力宣传和普及灾害后抢救伤员的基本知识。
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.
Objective To review the advances in repair of spinal cord injury by transplantation of marrow mesenchymal stem cells(MSCs). Methods The related articles in recent years were extensively reviewed,the biological characteristic of MSCs,the experimental and clinical studies on repair of spinal cord injury by transplantation of MSCs,the machanisms of immigration and therapy and the problems were discussed and analysed. Results The experimental and clinical studies demonstrated that the great advances was made in repair of spinal cord injury by transplantation of MSCs. After transplantation, MSCs could immigrate to the position of spinal cord injury, and differentiate into nervelike cells and secrete neurotrophic factors.So it could promote repair of injuryed spinal cord and recovery of neurologicalfunction. Conclusion Transplantation of MSCs was one of effective ways in repair of spinal cord injury, but many problems remain to be resolved.