改善微循环对大鼠坐骨神经损害血管内皮细胞生长因子表达及病理改变的影响

目的:探讨改善微循环对周围神经嵌压性损害血管内皮细胞生长因子(VEGF)表达和病理改变的影响。方法:分别检测坐骨神经嵌压后12、72h和7d背根神经节细胞VEGF水平与第4周神经干、神经节病理变化、脊髓病变神经元计数等,并运用正常对照组、模型组、前列地尔组和丁咯地尔组采用SPSS10.0统计软件进行方差分析统计处理。结果:嵌压后72hVEGF水平达到高峰,与正常对照组比较,其余各组均显著增加(P<0.01,P<0.05);前列地尔组和丁咯地尔组较模型组为优(P<0.01,P<0.05);嵌压后4周前列地尔组和丁咯地尔组的神经干、神经节病理变化、脊髓病变神经元计数均优于模型组(P<0.05)。结论:对于周围神经嵌压性损害,改善微循环可增加VEGF的表达并减轻其病理损害,从而对周围神经嵌压性损害的修复具有促进作用。     

钙通道阻滞剂对大鼠坐骨神经损伤后c-fos表达及神经功能的影响

目的探讨钙通道阻滞剂(CCB)对周围神经损伤后c-fos表达及神经功能的影响。方法制作坐骨神经嵌压性损伤大鼠模型,给予模型大鼠分别腹腔注射氟桂利嗪1mg/kg(低剂量组)、2mg/kg(高剂量组),或生理盐水10ml/kg(模型组)。在坐骨神经嵌压后第1周、第4周时取大鼠坐骨神经,采用免疫组织化学、行为医学和电生理学的方法测定c-fos阳性细胞数及第4周时足趾间距、神经传导速度(NCV);并与正常大鼠比较。结果(1)损伤后1周时,模型组、氟桂利嗪低剂量组坐骨神经c-fos阳性细胞数显著多于正常对照组(均P<0.01);氟桂利嗪高剂量组c-fos阳性细胞数轻度增加,也显著多于正常对照组(P<0.05),但明显少于模型组和氟桂利嗪低剂量组(均P<0.01);损伤4周时各组c-fos阳性细胞数均无明显增高。(2)损伤后4周时,模型组和氟桂利嗪低剂量组、高剂量组坐骨神经NCV显著慢于正常对照组(均P<0.01),氟桂利嗪低剂量组、高剂量组的NCV快于模型组(P<0.05,P<0.01)。(3)损伤后4周时,模型组大鼠右后肢足趾间距明显小于其他3组(均P<0.01);氟桂利嗪高剂量组、低剂量组与正常对照组比较差异无统计学意义(均P>0.05)。结论CCB使周围神经损伤后早期c-fos表达下调,并使神经功能受损减轻。     

实验性糖尿病大鼠坐骨神经VEGF表达的动态变化

目的 应用免疫组织化学的方法研究实验性糖尿病(DM)大鼠坐骨神经血管内皮生长因子(Vascu-lar endothelial growth factor,VEGF)的表达变化的动态规律.方法 采用大鼠腹腔内注射链脲菌素(STZ)溶液,制备实验性糖尿病大鼠模型.将80只Wistar大鼠随机分为正常对照组(NC组)、成模即刻(Ow)组、成模后4w组、8w组、12w组.应用免疫组织化学的方法观察VEGF在大鼠下肢坐骨神经中的动态表达规律.结果 在NC组大鼠中,坐骨神经轴索中一直没有见到VEGF棕黄色异染颗粒的表达.造模前DM各组和NC组大鼠下肢坐骨神经轴索中VEGF的表达无显著差异(P>0.05);DM组大鼠从4w开始出现VEGF在坐骨神经轴索中表达的棕黄色异染颗粒明显增多,DM 4w和8w组大鼠VEGF在坐骨神经轴索中的表达,分别与Nc组有极显著差异(P<0.01),但是DM 4w组和8w组之间没有显著差异(P>0.05).DM 12w时轴索中的VEGF的棕黄色异染颗粒明显减少,接近正常水平,与NC组没有显著差异(P>0.05),与DM 4w组和8w组分别具有极显著差异(P<0.01).无论是NC组,还是DM各组,VEGF在坐骨神经髓鞘上始终未见阳性表达.结论 正常生理情况下,VEGF在大鼠坐骨神经的轴索和髓鞘中均表达很少.高血糖状态下,VEGF在轴索的表达明显增多,髓鞘的表达没有变化.因此,VEGF主要在DM大鼠坐骨神经的轴索中表达,DM大鼠早期4w时周围神经VEGF的表达即可出现明显的增加,8w时达到高峰,此后逐渐减少,到12w时已经接近正常水平.     

坐骨神经损伤模型大鼠神经传导速度及损伤运动神经元内生长相关蛋白43表达与磁刺激干预

背景：磁刺激可促进损伤神经的修复。 目的：观察磁刺激对大鼠损伤坐骨神经神经传导速度及相应水平脊髓运动神经元内生长相关蛋白43表达的影响。 方法：将60只SD大鼠随机分为实验组(n=24)、模型组(n=24)和假手术组(n=12),用一新的长17 cm的止血钳钳夹坐骨神经至第二扣,以21.95×103 Pa维持10 s制备损伤模型。造模后24 h,实验组每天给予0.09 T的磁刺激。 结果与结论：造模后第2,4,8,12周,免疫组织化学染色显示实验组脊髓L4~5运动神经元生长相关蛋白43的表达较模型组相应时间点明显增高( P < 0. 05);造模后12周,电生理检测发现,与模型组比较,实验组再生神经传导速度加快,波幅升高,潜伏期缩短(P < 0.05)。说明磁刺激能提高损伤坐骨神经的传导速度,增加其对应脊髓节段运动神经元中生长相关蛋白43的表达,对大鼠损伤坐骨神经的修复起促进作用。     

输注表达VEGF的成纤维细胞和rAAV-VEGF基因对大鼠脑缺血保护作用的比较研究

目的:比较定向移植输注转染外源性VEGF(血管内皮细胞生长因子)基因的成纤维细胞(VEGF-成纤维细胞)和原位注射rAAV（重组腺相关病毒）载体介导的VEGF基因对大鼠缺血性脑保护的疗效,从而寻找出适合临床的安全、有效的基因治疗方法。方法:用线栓加环扎法建立SD大鼠大脑中动脉持续性闭塞(MCAO)模型。30只雄性SD大鼠随机分为假手术组、移植输注组、直接注射组、MCAO组和正常对照组。其中,移植输注组和直接注射组于术后24h内将VEGF-成纤维细胞和rAAV1-VEGF基因从大鼠脑缺血边缘区注入。结果: 移植VEGF-成纤维细胞和原位注射rAAV-VEGF基因均能减少脑梗死体积,且移植VEGF-成纤维细胞的作用明显优于原位注射基因,VEGF-成纤维细胞移植14d后大鼠脑内表达VEGF的阳性细胞数明显多于原位注射rAAV-VEGF治疗组。结论:移植VEGF-成纤维细胞比原位注射rAAV-VEGF治疗基因对脑缺血更具保护作用。     

骨间背神经嵌压症的治疗体会

骨间背侧神经嵌压症是指烧神经深支即骨间背侧神经受压而产生的伸拇、伸指功能障碍。作者自1986年以来共收治此症11例。现结合文献对此症的诊断及治疗作一总结。1临床资料11一般资料本组11例，男7例，女4例。最小年龄5岁，最大62岁，平均兀岁；右侧7例，左侧4例。3例有陈旧性益氏骨折病史，1例有类风湿性关节炎病史，2例有局部挤压伤病史，发病主治疗时间1－5个月，平均2．l月。12症状及体征所有患者均有不同程度的伸拇、伸措功能障碍。5例患者诉前臂近端疼痛，在前臂旋前及旅后时加重，2例在肘部有肿块，7例曾行肌电图检查显示骨间背神经传…     

坐骨神经非冻结性冷损伤时血神经屏障损害的研究

目的使用大鼠坐骨神经制造周围神经非冻结性冷损伤模型,观察非冻结性冷损伤时神经内部的水肿变化,研究冷损伤时血神经屏障功能的损害情况及相应的病理改变。方法 48只雄性Wistar随机分成冷损伤后1 d组、3 d组和5 d组。每只大鼠一侧坐骨神经予以3℃~5℃持续低温2 h;以对侧坐骨神经作为对照。每组大鼠在相应的时间点取下坐骨神经进行观察:静脉注射伊文思蓝后1 h,测量坐骨神经中伊文思蓝浓度;静脉注射伊文思蓝后1 h,坐骨神经包埋制片,在荧光显微镜下观察伊文思蓝的分布;坐骨神经包埋制片,在光学显微镜及电子显微镜下观察有髓纤维、无髓纤维及毛细血管的状况。结果冷损伤后1 d,多数有髓纤维出现以"空、暗"为形式的轴索退变;无髓纤维和紧密连接完好;神经内膜毛细血管管腔狭窄;冷损伤后3~5 d,有髓纤维病变继续加重;神经内膜毛细血管管腔仍然狭窄,内皮细胞间的紧密连接开放;冷损伤后1 d,冷损伤侧坐骨神经中的伊文思蓝浓度与对照侧相比有显著升高;在正常的坐骨神经内,伊文思蓝红色荧光局限于神经内膜的血管腔内,未渗漏至血管外;在冷损伤后1 d,坐骨神经的一些受冷部位出现了神经内膜弥漫性红色荧光;类似荧光也出现冷损伤后3 d与5 d的坐骨神经中,但是其荧光强度有所下降。结论坐骨神经非冻结性冷损伤可以导致血神经屏障功能破坏,引起神经内膜水肿;非冻结性冷损伤早期主要选择性损害有髓纤维,而对无髓纤维损伤极轻。     

盐酸丁咯地尔对面神经损害的保护作用

目的　探讨盐酸丁咯地尔对面神经损害的保护作用。方法　对 2 7例Bell麻痹患者进行随机分组 ,采用面神经传导速度和面神经功能恢复程度作为观察指标 ,观察盐酸丁咯地尔对面神经的保护作用。结果　盐酸丁咯地尔治疗组在治疗后 30d面神经传导速度恢复明显优于对照组 (P <0 0 1) ;面神经功能恢复程度在治疗后 30d治疗组优于对照组 (P <0 0 5 ) ;治疗后 6 0d治疗组恢复程度则显著优于对照组 (P <0 0 1)。结论　盐酸丁咯地尔对面神经损害具有保护作用。     

大鼠创伤性脑损伤VEGF表达的定量分析

在创伤性脑损伤（traumatic brain injury，TBI）的动物实验和临床研究中已发现血管内皮细胞生长因子（vascular endothelial growth factor，VEGF）的表达，认为TBI后VEGF的表达和上调与脑组织的自身保护有关。本研究应用激光共聚焦显微镜（laser scanning confocal microscopy，LSCM）对脑伤后动态VEGF表达进行荧光定量分析，以获得更为准确的VEGF表达时像，为应用VEGF治疗脑外伤提供一定的实验基础。     

Effects of repetitive conditioning crush lesions on regeneration of the rat sciatic nerve

The effect of repetitive conditioning lesions was tested on regeneration of the rat sciatic nerve. The nerve was conditioned by crush lesions one, two or three times with an interval of 2 or 4 days between each successive lesion. Axonal elongation was measured 3 days after a final test crush lesion. Two conditioning lesions stimulated axonal elongation more than one, while a third conditioning lesion had no further effect on axonal outgrowth. However, if the number of conditioning lesions were varied within a constant conditioning interval, outgrowth after the test lesion was the same. This suggests that the conditioning interval and not the number of conditioning lesions determined the outgrowth after a test lesion. When the conditioning lesion(s) and the test lesion were made at the same place, outgrowth was longer than if the lesions were spatially separated. Incorporation of [3H]thymidine in the regenerated nerve segment showed that proliferation of non-neuronal cells was initiated by each lesion. By counting the number of cell nuclei this proliferation was shown to correspond to an increase of cells in the regenerating nerve. It is therefore possible that the greater number of non-neuronal cells in the distal nerve segment accounts for the enhanced conditioning lesion effect in nerves where the conditioning and test lesions are made at the same place.     

Induction of VEGF and its Flt-1 receptor after sciatic nerve crush injury

Expression of vascular endothelial growth factor and its receptors Flt-1 and Flk-1 was studied in lumbar spinal cord after sciatic nerve crush injury. Immunohistochemical staining revealed strikingly different distribution of VEGF, Flt-1, and Flk-1 in lumbar motor neurons. VEGF was observed both in the nuclei and perikarya, while Flk-1 had cytoplasmic and Flt-1 perinuclear localization. Real-time RT-PCR showed a significant increase in the expression of VEGF and Flt-1 on the injured side of the lumbar spinal cord. The increased level of VEGF was also detected by immunoblot. Here we show that lumbar motor neurons increase the expression of VEGF and Flt-1 in response to injury. We propose that VEGF/Flt-1 signaling may be involved in regeneration of the spinal motor neurons.     

Neuroprotective effects of ultrasound-guided nerve growth factor injections after sciatic nerve injury

Nerve growth factor (NGF) plays an important role in promoting neuroregeneration after peripheral nerve injury. However, its effects are limited by its short half-life; it is therefore important to identify an effective mode of administration. High-frequency ultrasound (HFU) is increasingly used in the clinic for high-resolution visualization of tissues, and has been proposed as a method for identifying and evaluating peripheral nerve damage after injury. In addition, HFU is widely used for guiding needle placement when administering drugs to a specific site. We hypothesized that HFU guiding would optimize the neuroprotective effects of NGF on sciatic nerve injury in the rabbit. We performed behavioral, ultrasound, electrophysiological, histological, and immunohistochemical evaluation of HFU-guided NGF injections administered immediately after injury, or 14 days later, and compared this mode of administration with intramuscular NGF injections. Across all assessments, HFU-guided NGF injections gave consistently better outcomes than intramuscular NGF injections administered immediately or 14 days after injury, with immediate treatment also yielding better structural and functional results than when the treatment was delayed by 14 days. Our findings indicate that NGF should be administered as early as possible after peripheral nerve injury, and highlight the striking neuroprotective effects of HFU-guided NGF injections on peripheral nerve injury compared with intramuscular administration.     

Morphologic and morphometric evaluation of experimental acute crush injuries of the sciatic nerve of rats

In order to qualify and quantify nerve fiber lesion following an acute crush injury, a morphologic and morphometric study was carried out in 25 Wistar rats divided into five groups of five animals each according to the crushing load applied, i.e., 500, 1,000, 5,000, 10,000, and 15,000 g. The injury was produced under general anesthesia on a 5mm-long intermediate segment of the right sciatic nerve for 10 min using a dead-weight machine. The animals were killed with an excessive dose of anesthetics 72 h later and submitted to perfusion with a fixing solution through the abdominal aorta immediately after death. Both the right and left sciatic nerves were removed and prepared for histologic and morphometric examinations; 5 microm-thick sections stained with 1% Toluidine blue were examined under a light microscope equipped with a video camera linked to a computer loaded with a graphic program (KS 400). The morphometric studies included measuring total number of fibers, fiber density, fiber diameter, myelin fiber area, axon diameter, axon area and G ratio. The results showed that damage to the nerve fibers began to appear as early as with the 500 g load and was similar in all groups despite the load applied, increasing with the 10,000 and 15,000 g loads, although the external supporting tissues and small diameter fibers were preserved. The predominant type of lesion produced was axonotmesis.     

Neuroprotective effect of ischemic postconditioning on sciatic nerve transection

Ischemic preconditioning or postconditioning has been shown to have neuroprotective effect on cerebral ischemia,but it has not been studied in peripheral nerve injury.In this study,a rat model of sciatic nerve transection was established,and subjected to three cycles of ischemia for 10 minutes+reperfusion for 10 minutes,once a day.After ischemic postconditioning,serum insulin-like growth factor 1 expression increased;sciatic nerve Schwann cell myelination increased;sensory function and motor function were restored.These findings indicate that ischemic postconditioning can effectively protect injured sciatic nerve.The protective effect is possibly associated with upregulation of insulin-like growth factor 1.     

Neuroprotective effects of high-dose vs low-dose melatonin after blunt sciatic nerve injury

Introduction Melatonin, the secretory product of the pineal gland, has potent antioxidant properties. The aim of this study was to compare the effects of low-dose (10 mg/kg) vs high-dose (50 mg/kg) melatonin on early lipid peroxidation levels and ultrastructural changes in experimental blunt sciatic nerve injury (SNI). We believe this to be the first study to assess the dose-dependent neuroprotective effects of melatonin after a blunt peripheral nerve injury. Materials and methods Rats were randomly allocated into 5 groups of 10 animals each. The SNI only rats underwent a nerve injury procedure. The SNI plus vehicle group received SNI and intraperitoneal injection of vehicle (diluted ethanol) as a placebo. The SNI plus low-dose or high-dose melatonin groups received intraperitoneal melatonin at doses of 10 mg/kg or 50 mg/kg, respectively. Controls had no operation, melatonin or vehicle injection. SNI was induced by clamping the sciatic nerve at the upper border of the quadratus femoris for 2 min. Results Sciatic nerve samples were harvested 6 h after nerve injury and processed for biochemical and ultrastructural analysis. Trauma increased the lipid peroxidation of the sciatic nerve by 3.6-fold (153.85 ± 18.73 in SNI only vs 41.73 ± 2.23 in control rats, P < 0.01). Low (P = 0.02) and high (P < 0.01) doses of melatonin attenuated the nerve lipid peroxidation by 25% and 57.25%, respectively (65.76 ± 2.47 in high-dose vs 115.08 ± 7.03 in low-dose melatonin groups). Discussion Although low-dose melatonin reduced trauma-induced myelin breakdown and axonal changes in the sciatic nerve, high-dose melatonin almost entirely neutralized any ultrastructural changes. Conclusion Our results suggest that melatonin, especially at a dose of 50 mg/kg, has a potent neuroprotective effect and can preserve peripheral neural fibers from lipid peroxidative damage after blunt trauma. With further investigations, we hope that these data may prove useful to clinicians who treat patients with nerve injuries.     

Butyrate prevents muscle atrophy after sciatic nerve crush

Introduction: Histone deacetylases (HDACs) have been implicated in neurogenic muscle atrophy, but the mechanisms by which HDAC inhibitors might have beneficial effects are not defined. Methods: We used sciatic nerve crush to determine the effect of butyrate on denervation‐induced gene expression and oxidative stress. Results: Butyrate treatment initiated 3 weeks before injury and continued 1 week after injury increases histone acetylation and reduces muscle atrophy after nerve crush. Butyrate delivered only after nerve crush similarly prevented muscle atrophy. Butyrate had no effect on the increase in histone deacetylase 4 (HDAC4) protein levels following nerve crush but prevented the increase in expression of myogenin, MuRF1, and atrogin‐1. Butyrate did not affect mitochondrial reactive oxygen species production, but it increased antioxidant enzyme activity, reduced proteasome activity, and reduced oxidative damage following nerve injury. Conclusions: These data suggest that HDAC inhibitors are promising pharmacological agents for treating neurogenic muscle atrophy. Muscle Nerve 52: 859–868, 2015