Suppression of detrusor-sphincter dyssynergia by immunoneutralization of nerve growth factor in lumbosacral spinal cord in spinal cord injured rats

PURPOSE: We investigated the effects of intrathecal application of nerve growth factor (NGF) antibodies (NGF-Abs) and desensitization of C-fiber afferent pathways by capsaicin treatment on detrusor-sphincter dyssynergia (DSD) after spinal cord injury (SCI). MATERIALS AND METHODS: In adult female rats SCI was induced by complete transection of the spinal cord at Th8 to 9. Ten days after spinalization vehicle or NGF-Ab (10 microg daily) was continuously administered at the level of the L6-S1 spinal cord through an implanted intrathecal catheter connected to an osmotic pump for 2 weeks. Another group of spinalized rats was treated with capsaicin (125 mg/kg subcutaneously) 3 weeks after spinalization and 5 days before experiments. Simultaneous recordings of intravesical pressure and urethral perfusion pressure were then performed. NGF levels in the L6 spinal cord were measured in vehicle or NGF-Ab treated spinalized rats using enzyme-linked immunosorbent assay. RESULTS: DSD was observed in all vehicle treated spinalized rats. The average urethral pressure increase at the peak bladder contraction was significantly lower by 84% and 78% in NGF-Ab and capsaicin treated spinalized rats, respectively, than in vehicle treated rats. After NGF-Ab treatment NGF levels were significantly decreased by 38% in the L6 spinal cord compared with vehicle treated spinalized rats, in which NGF levels in the L6 spinal cord were 7 times higher than in spinal intact rats. CONCLUSIONS: Increased levels of NGF in the spinal cord could contribute to the emergence of DSD that is at least in part mediated by C-fiber bladder afferents after SCI. Thus suppression of NGF levels in afferent pathways could be useful for treating DSD following SCI.     

胚胎脊髓组织移植联合应用神经生长因子对损伤脊髓再生修复的形态学影响

选择胎龄为１４～１５天的大鼠胚胎脊髓植入成年大鼠半横断的脊髓损伤腔，同时局部应用神经生长因子。术后２～８个月，用组织学、免疫细胞化学、辣根过氧化酶示踪及超微结构的检查方法证实，移植组织在宿主脊髓内的存活率为９０％，并且分化成熟，具有正常的神经组织结构特征，大多数移植物充满损伤腔，与宿主脊髓形成良好的融合，移植组织与宿主组织出现新的纤维联系，使脊髓损伤的两端恢复了解剖的连续性。     

胚胎脊髓组织移植合用神经生长因子对损伤脊髓功能恢复的影响

将１４－１５天的胚胎脊髓组织移植到成年Ｗｉｓｔａｒ大鼠半横断脊髓损伤腔，术后１－６个月，通过爬坡，网格板走步，Ｔａｒｌｏｖ运动分级和电生理的检查，评价损伤脊髓的功能恢复程度，在移植组动物，术后可见后肢运动功能逐渐恢复，６个月时，恢复的程度接近正常水平，对照组运动功能检查未见明显的改善，结果提示，胚胎脊髓组织移植在一定程度上有助于损伤脊髓的功能恢复。     

大鼠脊髓损伤后神经生长抑制因子Nogo-A的表达

目的研究神经生长抑制因子Nogo—A在大鼠脊髓损伤组织中不同时间点的表达情况．探讨Nogo—A基因在脊髓损伤时对神经再生的作用．方法建立急性脊髓损伤模型,采用原位杂交技术结合免疫组化技术检测。结果原位杂交法显示：Nogo-A mRNA在脊髓损伤后1d表达下降,3d升高,7d表达最高.免疫组化显示：Nogo—A含量在脊髓损伤后1d表达下降,3d开始上升,7d表达最高.结论Nogo-A在脊髓损伤后1d表达不明显,而后随时间的延长表达逐渐增加．表明脊髓损伤后Nogo-A表达先降低后升高．可能是造成成年哺乳动物损伤后神经再生障碍的重要原因之一.     

神经生长因子对大鼠脊髓损伤后一氧化氮合成酶含量的影响

探讨神经生长因子（ＮＧＦ）对脊髓损伤保护作用的机制。方法采用Ａｌｉｅｎ’ｓ法以２５ｇｃｍ致伤大鼠Ｔ８脊髓,经蛛网膜下腔导管分别于术后即刻、３０分钟、１、２、３、４、８、１２、２４小时各注入ＮＧＦ溶液,并与生理盐水组和正常对照组作对照。采用放射强度测定法测定一氧化氮合成酶（ＮＯＳ）含量。结果与正常组相比较,ＮＯＳ含量在伤后１０分钟、１、２、４、８小时均显著升高（Ｐ＜０．０１）,ＮＧＦ治疗组与生理盐水组相比较,在伤后１０分钟、１、２、４、８小时ＮＯＳ活性明显下降（Ｐ＜０．０１）。结论ＮＧＦ通过抑制脊髓损伤后ＮＯＳ的升高效应,抑制了一氧化氮（ＮＯ）的神经毒性作用,从而保护了神经组织。     

Urinary bladder biopsies in spinal cord injured patients

STUDY DESIGN: A series of 94 urinary bladder biopsies in spinal cord injured (SCI) patients were histopathologically and statistically analysed. OBJECTIVES: The following hypotheses were examined: (1) The number of clinical bladder infections per year in each patient does not influence the histopathological type of inflammation of the urinary bladder; (2) The duration of the spinal cord lesion does not have a strong effect on the type of inflammation; (3) The different neurological levels (upper and lower motor neuron lesions) do not relate to a specific histopathology. SETTINGS: All patients received their treatment at the Swiss Paraplegic Centre in Nottwil, near Lucerne (Switzerland). METHODS: The samples were taken from the bladder fundus during endoscopic urologic operations. Histopathological standard procedures were carried out. Statistical analysis including Kruskal-Wallis and Chi-square tests were performed. RESULTS: Histopathological analysis showed abnormal alterations of the urinary bladder mucosa in 86 SCI-patients: (91.5%). 63 cases (67.0%) showed a chronic type and 23 cases (24.5%) showed a subacute type of inflammation. A normal urinary bladder was found in eight cases (8.5%). The three hypotheses were statistically not rejected. CONCLUSION: Results demonstrated no correlation between the number of bladder infections per year, the period since injury, the neurologic level of the spinal cord lesion and the histopathology of the urinary bladder mucosa.     

Effect of nerve growth factor on neuronal apoptosis after spinal cord injury in rats

OBJECTIVE: To explore the molecular mechanism of the protective effect of nerve growth factor (NGF) on injured spinal cord. METHODS: The posterior T(8) (the 8th thoracic segment) spinal cords of 60 Wistar rats were injured by impacts caused by objects (weighing 10 g) falling from a height of 2.5 cm with Allen's way. Solution with nerve growth factors (NGF) was given to 30 rats (the NGF group) through a microtubule inserted into the subarachnoid cavity immediately, and at 2, 4, 8, 12 and 24 hours after spinal cord injury (SCI) respectively. Normal saline (NS) with same volume was given to the other 30 rats (the NS group) with the same method. And 5 normal rats were taken as the normal controls. The expression of bcl-2 and bax proteins in spinal cord was detected with immunohistochemistry. The apoptotic neurons in spinal cord were measured with terminal deoxynucleotidyl transferase-mediated dUTP-biotin nick end-labeling of DNA fragments (TUNEL) staining. RESULTS: The positive expression of bcl-2 protein was strong in the normal controls, but decreased in the NS group, and increased significantly in the NGF group as compared with that of the NS group (P<0.01). The positive expression of bax protein was also strong in the normal controls, but increased in the NS group, and decreased significantly in the NGF group as compared with that of the NS group (P<0.01). Apoptotic neurons were found in the NS group, and they decreased significantly in the NGF group as compared with that of the NS group (P<0.01). CONCLUSIONS: NGF can protect the injured nerve tissues through stimulating the expression of bcl-2 protein, inhibiting the expression of bax protein and inhibiting the neuronal apoptosis after SCI.     

脊髓损伤大鼠的阴茎海绵体肌电图研究

目的探讨海绵体肌电图诊断脊髓性勃起功能障碍的价值。方法将24只成年雄性SD大鼠(300～400 g)分成:对照组、T9和L6损伤组(每组8只)。损伤脊髓1周后,用肌电图仪采集注射阿朴吗啡前后阴茎肌电数据,采集频率20～3 000 Hz、扫描速度5 ms／d、灵敏度10 μV／d。用t检验方法分析统计数据。结果对照组使用阿朴吗啡10 min均方根振幅为(5．60±0．89)μV, 大于T9损伤组(3．60±1．14)μV(P<0．05);使用阿朴吗啡前、使用后5 min和10 min高／低功率比均为0．05±0．03,小于L6损伤组0．13±0．04、0．15±0．07、0．13±0．07(P<0．05)。T9损伤组使用阿朴吗啡后5 min和10 min平均频率分别为(122．40±47．99)、(151．80±76．42)Hz,较L6损伤组(278．83±118．66)、(265．00±81．35)Hz低(P<0．05)。结论海绵体肌电图对脊髓性勃起功能障碍有诊断价值。     

Effects of nerve growth factor on N-methyI-D-asparate receptor 1 after spinal cord injury in rats

To explore the effects of the nerve growth factor ( NGF ) on N-methyI-D-asparate receptor 1(NMDAR 1 ) after spinal cord injury. Methods: Spinal cord injury of Wistar rats was performed with Allen's method by a 10 g x 2.5 cm impact on the posterior T8 spinal cord. NGF was given to the rats of the treatment group via subarachnoid space tube at once,2, 4, 8, 12 and 24 hours after spinal cord injury,respectively. The expression of NMDAR1 mRNA in spinal cord was detected by in situ hybridization. Results: Rare expression sequence of NMDAR1 mRNA was found in rat spinal cord of the normal group. A strong expression sequence of NMDAR1 mRNA was found in rat spinal cord of the normal saline group. The expression of NMDAR1 mRNA in the NGF group was significantly decreased as compared with that in the normal saline group ( P ＝ 0.01 ). Conclusions: NGF can relieve damage of injured spinal cord by prohibiting the expression of NMDAR1 mRNA.     

神经生长因子对大鼠脊髓损伤后神经元凋亡的影响

目的探讨神经生长因子(NGF)对脊髓损伤保护作用的分子机制.方法采用Allen's法以25 gcm力致伤大鼠T8脊髓,经蛛网膜下腔导管于术后即刻、2、4、8、12、24 h各注入NGF溶液,并与生理盐水组(NS组)和正常对照组作对照,采用免疫组织化学方法和末端单位标记法(TUNEL)原位末端标记法分别检测bcl-2、bax蛋白在脊髓神经元的表达及神经元凋亡情况.结果正常组中脊髓灰质bax蛋白阳性细胞吸光度(A)值为34.51±4.47,NS组中bax蛋白表达增加,以2 h及12 h最为显著,而NGF组与NS组相比,bax蛋白表达明显减少(P＜0.01).正常组中脊髓灰质bcl-2蛋白表达的A值为19.72±2.92,NS组中bcl-2表达下降,而NGF组与NS组相比较,bcl-2蛋白表达明显增多(P＜0.01).TUNEL检测结果显示,正常对照组中未见神经元凋亡,NS组中自2 h后可见神经元凋亡,NGF组与NS组相比,神经元凋亡指数明显减少(P＜0.01).结论NGF能通过抑制bax蛋白的表达,促进bcl-2表达抑制脊髓损伤后神经元凋亡,从而保护损伤的脊髓组织,这可能是NGF对脊髓损伤具有保护作用的机制之一.     

Eeffects of nerve growth factor on N—methyl—D—asparate receptor 1 after spinal cord injury in rats

OBJECTIVE: To explore the effects of the nerve growth factor (NGF) on N-methyl-D-asparate receptor 1 (NMDAR 1) after spinal cord injury. METHODS: Spinal cord injury of Wistar rats was performed with Allen's method by a 10 gx2.5 cm impact on the posterior T8 spinal cord. NGF was given to the rats of the treatment group via subarachnoid space tube at once, 2, 4, 8, 12 and 24 hours after spinal cord injury, respectively. The expression of NMDAR1 mRNA in spinal cord was detected by in situ hybridization. RESULTS: Rare expression sequence of NMDAR1 mRNA was found in rat spinal cord of the normal group. A strong expression sequence of NMDAR1 mRNA was found in rat spinal cord of the normal saline group. The expression of NMDAR1 mRNA in the NGF group was significantly decreased as compared with that in the normal saline group (P=0.01). CONCLUSIONS: NGF can relieve damage of injured spinal cord by prohibiting the expression of NMDAR1 mRNA.     

Effects of nerve growth factor on neuronal nitric oxide production after spinal cord injury in rats

OBJECTIVE: To explore the protective effects of nerve growth factor (NGF) on injured spinal cord. METHODS: The spinal cord injury (SCI) model of Wistar rats was established by a 10 gx2.5 cm impact force on the T(8) spinal cord. NGF (60 microg/20 microl) was given to the rats of the treatment group immediately and at 2, 4, 8, 12, 24 hours after SCI. The level of neuronal constitutive nitric oxide synthase (ncNOS) and the expression of ncNOS mRNA in the spinal cord were detected by the immunohistochemistry assay and in situ hybridization method. RESULTS: Abnormal expression of ncNOS was detected in the spinal ventral horn motorneuron in injured rats. The levels of ncNOS protein in the NGF group were significantly lower than those in the normal saline group (P<0.05 ). The ncNOS mRNA expression was found in the spinal ventral horn motorneuron in injured rats and the expression in the NGF group was significantly decreased compared with that in the normal saline group (P<0.01). CONCLUSIONS: NGF can protect the injured tissue of the spinal cord by prohibiting abnormal expression of nitric oxide synthase and the neurotoxicity of nitric oxide.     

Effects of topically administered nerve growth factor on axonal regeneration in peripheral nerve autografts implanted in the spinal cord of rats

The effect of exogenous nerve growth factor (NGF) on axonal regeneration into autologous peripheral nerve (PN) grafts implanted to the spinal cord (SC) of rats was assessed by retrograde labeling of the parent soma of the regenerating axons with horseradish peroxidase. NGF was delivered at the graft site over periods of 15 and 30 days by using indwelling osmotic minipumps. In control rats, the minipumps were filled with saline. At 15 days after grafting in the NGF-treated rats, the mean number of SC as well as dorsal root ganglion (DRG) neurons that regenerated their axons into the peripheral nerve grafts was increased 55.3 and 26.4 times, respectively, as compared to the control group values. At 30 days, SC and DRG neurons in the NGF-treated group were 10.9 and 3.1 times greater than in the control group. In the NGF-treated group, the regenerating SC neurons were located within a range of 7 to 13 mm from the graft site as compared to 1 to 7 mm in the control group. Finally, the analysis of the soma diameters of the regenerating neurons showed that NGF enhanced and maintained with time the regenerative response from small-sized DRG neurons. Therefore, NGF is thought to promote directly the regenerative potential of SC as well as DRG neurons and to exert an indirect glial cell-mediated effect at the SC-graft interface.     

Adaptations in the walking pattern of spinal cord injured rats

Walking ability is a measure of recovery used in many studies that test experimental strategies to treat injuries or diseases of the central nervous system (CNS) in animal models. A common measure in the rat animal model of thoracic spinal cord injury (SCI) is visual inspection and scoring of hind limb activity, which allows the documentation of movements associated with the recovery of locomotor function. In this study, we expand on previously documented visible changes in the locomotor pattern following SCI. The spontaneous recovery of locomotion in rats with thoracic SCIs of variable extent was evaluated using electromyographic (EMG) and kinematic analysis while rats walked on an elevated runway. Comparisons with pre-lesion walking sequences revealed changes in the kinematics and in the muscle activation pattern of various muscles, including enhanced fore limb extensor activity, possibly reflecting an increased contribution to propulsion, altered recruitment of back muscles inserting into the hip (possibly to support stepping movements), and elevated posture during stance, which may compensate for deficits in weight support. These changes were noted in spinal cord injured rats with varying degrees of impairment, including animals with no visually detectable deficit in open-field walking. In summary, the presented results demonstrate that spinal cord injured rats develop alternative locomotor patterns following SCI that cannot be discriminated by the use of qualitative visually based analysis, thus urging the use of quantitative outcome measures in assessing motor function after SCI.     

Conservative treatment of the neuropathic bladder in spinal cord injured patients.

Different conservative treatment modalities for the lower urinary tract dysfunction in patients with spinal cord lesion are reviewed. Conservative treatment is still the mainstay of the urological management in these patients. Growing experience has changed the classical approach. Spontaneous voiding with and without triggered voiding and/or bladder expression has proven to be less safe except in well defined patients with regular urological follow-up. Nowadays, intermittent catheterisation and self catheterisation with and without bladder relaxants are accepted as the methods of choice. Condom catheters are still needed if incontinence persists, while penile clamps have no place in the treatment of patients with spinal cord lesions. Long-term indwelling catheters should be avoided. External electrical stimulation can be used to correct the neurogenic dysfunction by neuromodulation and/or to induce a direct therapeutic response in the lower urinary tract.     

蛛网膜下腔应用神经生长因子对鼠脊髓神经生长相关蛋白-43 mRNA表达的影响

目的　研究蛛网膜下腔注射神经生长因子 (NGF)对脊髓损伤 (SCI)组织神经生长相关蛋白 43 (GAP 43 )mRNA表达水平的影响。方法　用Allen氏重物坠落法制作鼠脊髓损伤模型。66只成年Wistar鼠随机分为 11组 ,正常组、SCI 1、4、7、10、14d组和NGF 1、4、7、10、14d治疗组 ,每组各 6只。用逆转录 聚合酶链反应 (RT PCR)检测鼠损伤脊髓组织中GAP 43mRNA表达水平。结果　GAP 43mRNA在正常成年鼠脊髓中微量表达 ,SCI后表达增加且NGF治疗组较SCI组表达更为显著 (P <0 .0 5 )。术后 7d时 ,SCI组GAP 43mRNA表达达到高峰 (0 .82 5± 0 .0 16) ,14d时降至接近初始水平 (0 .419± 0 .0 18) ,但NGF治疗组GAP 43mRNA表达仍维持较高水平 (0 .787±0 .0 10 )。结论　蛛网膜下腔注射NGF可增强损伤脊髓组织GAP 43mRNA表达。