硫酸镁对大鼠继发性脊髓损伤保护作用的实验研究

为探讨硫酸镁对大鼠继发性脊髓损伤的保护作用及机制.用30只体重280±20g wister成年大白鼠随机分为三组:A组(对照组),仅行T10阶段椎板减压;B组(损伤组),C组(治疗组),均行T10阶段椎板减压和Allen's重物打击致脊髓损伤,伤后30min时B组腹腔注射蒸馏水1600mg/kg,C组腹腔注射硫酸镁1600m//kg.48h后切去伤段脊髓组织分别测定H2O、Ca2+、Mg2+离子含量,观察局部组织病理学改变,超微结构及单位面积的凋亡细胞数.结果显示跟A组比较,B、C组损伤段脊髓组织H2O、ca2+含量增多,Mg2+含量减少,组织病理学及超微结构破坏严重,凋亡细胞数升高,而且C组较B组轻.由此可知,病程早期应用硫酸镁可以减轻脊髓损伤后的继发性损伤,从而对受损脊髓起到保护作用.     

大鼠脊髓楔型半切空洞模型的建立及评估

摘要: 目的建立一种新型大鼠脊髓半切模型,为临床脊髓空洞损伤研究提供适宜的动物模型。方法25 只SD 大鼠随机分为脊髓楔型块状半切组( A 组,n = 10) 、假手术组( B 组,n = 10) 和正常对照组( C 组,n = 5) 。术后采用 BBB 运动功能评分、斜板试验、HE 染色和核磁共振( MRI) 检测综合评价脊髓半切模型的稳定性。结果术后A 组 大鼠伤侧后肢BBB 运动功能评分及斜板维持最大角度值显著低于B 组和C 组( P ＜ 0. 05) ,而这些指标在B 组和C 组之间没有明显差异; 术后28 d HE 和MRI 检测显示脊髓损伤区( A 组) 灰质和白质发生明显的形态学改变。结论 通过该方法建立的脊髓半切模型稳定、可靠,适于脊髓空洞性损伤的研究。     

大鼠急性脊髓损伤后肝癌衍生生长因子的表达

目的:观察大鼠受损伤脊髓组织中肝癌衍生生长因子(Hepatoma-derived growthfactor,HDGF)表达的变化.方法:将40只成年大白鼠随机分成对照组(A组)和脊髓损伤组(B组),每组20只.脊髓损伤组采用改良的Allen’s打靶法制备,并于术后24 h处死大鼠,取损伤脊髓节段进行免疫组织化学染色.观察HDGF在正常对照组以及脊髓损伤后表达情况.以表达指数作为统计学指标,采用X2检验分析各组间的变化.结果:HDGF主要表达在神经细胞核中.15例损伤脊髓标本表现为HDGF表达指数为Ⅱ组,对照组中表达指数为Ⅱ组仅4只(P<0.05).结论:HDGF高表达于损伤脊髓组织中,提示HDGF可能参与脊髓损伤的修复.     

Studies on repairing of hemisected thoracic spinal cord of adult rats by using a chitosan tube filled with alginate fibers

A chitosan tube filled with alginate fibers was implanted into the injured spinal cord of a rat for repairing the damaged tissue. Twelve months after the operation, the morphological observation demonstrated that this chitosan tube could induce regeneration of myelinated and non-myelinated axons and blood vessels. The Basso-Beattie-Bresnahan (BBB) behavioral evaluation confirmed that the implants played a key role in the long-term restoration of rats motor functions. It is a promising start in the treatment of the patients with the injury of the spinal cord.     

Spinal cord decompression reduces rat neural cell apoptosis secondary to spinal cord injury

Objective: To determine whether spinal cord decompression plays a role in neural cell apoptosis after spinal cord injury. Study design: We used an animal model of compressive spinal cord injury with incomplete paraparesis to evaluate neural cell apoptosis after decompression. Apoptosis and cellular damage were assessed by staining with terminal deoxynucleotidyl transferase (TdT)-mediated deoxyuridine triphosphate nick-end labelling (TUNEL) and immunostaining for caspase-3, Bcl-2 and Bax. Methods: Experiments were conducted in male Sprague-Dawley rats (n=78) weighing 300~400 g. The spinal cord was compressed posteriorly at T10 level using a custom-made screw for 6 h, 24 h or continuously, followed by decompression by removal of the screw. The rats were sacrificed on Day 1 or 3 or in Week 1 or 4 post-decompression. The spinal cord was removed en bloc and examined at lesion site, rostral site and caudal site (7.5 mm away from the lesion). Results: The numbers of TUNEL-positive cells were significantly lower at the site of decompression on Day 1, and also at the rostral and caudal sites between Day 3 and Week 4 post-decompression, compared with the persistently compressed group. The numbers of cells between Day 1 and Week 4 were immunoreactive to caspase-3 and B-cell lymphoma-2 (Bcl-2)-associated X-protein (Bax), but not to Bcl-2, correlated with those of TUNEL-positive cells. Conclusion: Our results suggest that decompression reduces neural cell apoptosis following spinal cord injury.     

狂犬病毒糖蛋白衍生物作为靶脑载体初探

血脑屏障（blood-brain barrier, BBB）阻碍了具有治疗潜力的大分子化合物从外周组织进入脑内。为了寻找一种高效、快速通过BBB的靶向性载体,本实验通过罗丹明B标记的狂犬病毒糖蛋白衍生肽（RDP）注射入昆明小鼠体内,与15min、5h取大脑、脊髓及肝、肾等外周组织,冷冻切片观察其在体内的分布,并通过构建pET28a-RDP-luciferase重组质粒,结果发现融合蛋白能快速的穿过血脑屏障分布于中枢神经系统,为治疗中枢神经系统的药物开发提供新的思路。     

补阳还五汤对脊髓损伤大鼠体重及后肢运动功能的影响

目的探讨补阳还五汤对脊髓损伤大鼠体重及后肢运动功能影响与其神经保护作用的关系。方法采用Allen’s打击法制作中度SCI模型,应用SPF级Wistar大鼠,随机分为4组：正常组和3个模型组,即模型空白组、BYHWD组、金纳多组,每组16只大鼠。模型组大鼠分别给予蒸馏水、BYHWD、金纳多水溶液,正常组给予蒸馏水,分别于造模前即0 d、造模后3 d、1 w、2 w、3 w,称量大鼠体重,并进行后肢运动功能评价,灌胃治疗2 w后,结束实验。结果SCI模型大鼠于造模后3 d体重及后肢运动功能均明显降低,灌胃治疗后,模型空白组大鼠体重缓慢增加,但后肢运动功能无明显改善;BYHWD组及金纳多组大鼠体重及后肢运动功能均有显著改善,且BYHWD组改善效果更明显,与金纳多组比较差异有显著性。结论BYHWD通过保护SCI大鼠脊髓组织,显著改善大鼠后肢运动功能,增加大鼠体重,为其治疗中医＂痿证＂提供了新的实验依据。     

挫伤型脊髓损伤动物模型制作方法研究进展

摘要:脊髓损伤目前尚无有效的治疗方法,因此建立一个理想的动物模型对于确定脊髓损伤机制和开发脊髓损伤患者的治疗方法具有重要意义。 本文系统地回顾和分析了挫伤型脊髓损伤造模装置的研究进展,并对其优缺点进行了评价,以供进一步研究。     

复方丹参注射液与甲基强地松龙联合应用对大鼠急性脊髓损伤的影响

观察丹参SalviaMilltiorrhiza(SM)与甲基强地松龙Methylprednisolne(MP)的联合应用对急性脊髓损伤产生的影响及其超微结构变化。用50只成年SD大白鼠随机分为:正常对照组、损伤对照组、丹参组、激素组、联合用药组。除正常组外,其他4组均按改良Allen打击法致伤脊髓,造成大鼠不完全的瘫痪。每天观察各组大鼠的行为变化,从3个不同角度的神经功能试验给予评分。第4天经心一主动脉插管灌注固定液处死各组大白鼠,取出损伤段脊髓,制作冰冻切片HE染色进行光镜观察及电镜超薄切片进行观察。结果显示:斜板试验损伤对照组功能恢复最慢,其次为丹参组、激素组,联合用药组恢复功能最快。联合用药组与激素组、丹参组比较均有显著性差异(p<0.05),BBB评分方差分析显示联合用药组与激素组、丹参组有统计学差异(p<0.05),与损伤对照组比较有非常显著性差异(p<0.01)。5组中灰质和白质均有不同程度出血、神经元水肿、变性、坏死,显示不出明显的差异,损伤对照组中髓鞘有较严重的披裂,轴索残存或内有碎处,大多数轴索极度损伤,突触小泡明显减少。激素组及丹参组的情况与损伤对照组大致类似,只是程度稍轻,联合用药组髓鞘及轴索、线粒体、毛细血管、突触小泡等损伤改变最轻,有些结构接近正常,突触小泡数与其他组相比有显著差异。甲     

Dynamics of total culturable bacteria and its relationship with methylmercury in the soils of the water level fluctuation zone of the Three Gorges Reservoir

Field investigations were conducted to study the temporal and spatial distribution characteristics of total culturable bacteria(TCB)and its relationship with methylmercury(MeHg)in the soils of the water level fluctuation zone of the Three Gorges Reservoir.Different altitudes(170–180,170–175,165–170 and 160–165 m)in Zhenxi(Site 1),Shibaozhai(Site 2)and Tujing(Site 3),Chongqing,China were chosen as sampling sites.Results indicated that TCB did not have significant difference in the top(0–10 cm)and sub(10–20 cm)soil of the non-inundated area(175–180 m),but showing a significant difference in the water level fluctuation zone(\175 m,suggesting that water level fluctuation had an important effect on TCB.Moreover,TCB in soils of various altitudes of Site 1 and 2had significant difference,while for Site 3,this difference was not significant.And the difference of TCB in Site 2was much greater than that in Site 1.These results suggested that there were significant differences for TCB in soils of mainstream and tributaries.In addition,TCB in soils of 10–20 cm had significant or highly significant positive correlations with MeHg level(r C 0.762,P B 0.048),thus we assumed that there may be some aerobic microorganisms playing dominant roles in mercury methylation.     

体育功能锻炼对截瘫患者康复影响及评价分析

目的:探讨体育功能锻炼对截瘫患者后期康复治疗的影响及康复评价.方法:76例在脊髓损伤后出现截瘫患者,进行体育功能锻炼的康复治疗,追踪记录,采用美国脊髓损伤学会(ASIA)脊髓损伤神经功能分类国际标准评价康复效果.结果:经统计,胸腰髓不完全损害者康复锻炼前后ASIA损伤评分运动、感觉评分均有显著意义(P<0.05).胸腰髓完全损伤者运动、感觉ASIA评分好转较明显(P<0.05).结论:体育功能锻炼能帮助截瘫患者后期恢复,显著改善和提高患者的综合功能.     

粘弹性介质的碰撞特征

本文研究了粘弹性材料的碰撞特征。指出随阻尼比增加,碰撞力呈非线性变化,撞击力极值出现的时间提前,能量按指数规律耗散。同时,随阻尼比增加,材料性质由Hook固体转化为Newton流体。 对动物脊髓进行打击实验研究的结果与上述理论相一致。     

大鼠坐骨神经切断后经皮低频高强度电刺激相应脊髓节段中GAP-43表达的变化

目的探讨成年Wister大鼠在坐骨神经切断后GAP-43于相应脊髓节段前角运动神经元内的表达变化.方法选取健康成年雄性Wister大鼠60只,将坐骨神经切断,随机分为实验组和对照组,实验组给予经皮低频高强度电刺激,分别于术后1,2,4,8,12,16周处死,取其L4~L6脊髓,利用免疫组织化学技术检测GAP-43在相应脊髓节段中的表达变化,并利用影像分析系统进行统计学分析.结果对照组:1周时前角细胞胞体内GAP-43有明显表达,4周时达到高峰,5~8周时逐渐下调,9~16周时GAP-43在前角细胞胞体内中仍有少量表达,并呈弱阳性.实验组:1周时前角细胞胞体内GAP-43有明显表达,2周时达到高峰,且在4~16周时在神经元中仍有表达,并呈阳性.结论坐骨神经切断可导致成年大鼠相应脊髓节段中前角运动神经元GAP-43表达明显增加,可证明在周围神经损伤后神经元的再生能力增强,但时效很短.而给予低频高强度电刺激疗法后,GAP-43的表达在时长和量上都有明显增加.     

Preliminary animal studies on observation of injured spinal cord with intraoperative ultrasound backscatter microscopy

Many studies have shown that strategies of nerve regeneration and cell-based transplantation are valid based on animal models of spinal cord injury (SCI).To apply these strategies and bridge spinal cord defects,the identification and precise localization of lesions during spinal cord surgery is necessary.The aim of the present experiment was to evaluate the capabilities of ultrasound backscatter microscopy (UBM) in identifying morphologic changes after SCI.After laminectomy,high-resolution ultrasound images of the spinal cord were obtained in one normal and seven spinal cord-injured adult Wistar rats using a UBM system with a 55-MHz center frequency scanner.Comparison between histoanatomic and UBM images was also performed.The results showed that UBM can identify cysts after the experimental SCI is removed in adult rats.In addition,the glial scar formed in secondary injury showed obvious hyperechoic speckle in the UBM image and correlated with the histoanatomic image.UBM has obvious clinical value in nerve regeneration and cell-based transplantation strategies in injured spinal cords.     

Restoration of grasp following paralysis through brain-controlled stimulation of muscles

Patients with spinal cord injury lack the connections between brain and spinal cord circuits that are essential for voluntary movement. Clinical systems that achieve muscle contraction through functional electrical stimulation (FES) have proven to be effective in allowing patients with tetraplegia to regain control of hand movements and to achieve a greater measure of independence in daily activities. In existing clinical systems, the patient uses residual proximal limb movements to trigger pre-programmed stimulation that causes the paralysed muscles to contract, allowing use of one or two basic grasps. Instead, we have developed an FES system in primates that is controlled by recordings made from microelectrodes permanently implanted in the brain. We simulated some of the effects of the paralysis caused by C5 or C6 spinal cord injury by injecting rhesus monkeys with a local anaesthetic to block the median and ulnar nerves at the elbow. Then, using recordings from approximately 100 neurons in the motor cortex, we predicted the intended activity of several of the paralysed muscles, and used these predictions to control the intensity of stimulation of the same muscles. This process essentially bypassed the spinal cord, restoring to the monkeys voluntary control of their paralysed muscles. This achievement is a major advance towards similar restoration of hand function in human patients through brain-controlled FES. We anticipate that in human patients, this neuroprosthesis would allow much more flexible and dexterous use of the hand than is possible with existing FES systems.     

Origin of the Moon in a giant impact near the end of the Earth's formation

The Moon is generally believed to have formed from debris ejected by a large off-centre collision with the early Earth. The impact orientation and size are constrained by the angular momentum contained in both the Earth's spin and the Moon's orbit, a quantity that has been nearly conserved over the past 4.5 billion years. Simulations of potential moon-forming impacts now achieve resolutions sufficient to study the production of bound debris. However, identifying impacts capable of yielding the Earth-Moon system has proved difficult. Previous works found that forming the Moon with an appropriate impact angular momentum required the impact to occur when the Earth was only about half formed, a more restrictive and problematic model than that originally envisaged. Here we report a class of impacts that yield an iron-poor Moon, as well as the current masses and angular momentum of the Earth-Moon system. This class of impacts involves a smaller-and thus more likely-object than previously considered viable, and suggests that the Moon formed near the very end of Earth's accumulation.     

Dick氏内固定器治疗胸腰椎骨折脱位并脊髓损伤

为寻求和解决胸腰椎骨折脱位并脊髓损伤的有效疗法,用DICk氏内固定器治疗53例患者,并随访．对临床资料进行总结分析。结果表明,Dick氏内固定系统符合脊柱的生物力学原理,可使固定节段具有高度的内在稳定性,且具有操作简便、安全、短节段固定,合并症少等优点。     

撞击物对复合材料层合板冲击损伤特性的影响

针对一种采用预浸料成型工艺制备的复合材料层合板,开展不同撞击物作用下复合材料层合板低能量冲击损伤特性研究. 通过对比相同冲击能量（60 J）下,钢球、铝球和聚合物球撞击复合材料层合板的落锤/气炮冲击试验结果和冲击后含损伤结构的压缩试验结果,研究了不同撞击因素对复合材料低能量冲击损伤面积和剩余压缩强度的影响. 结果表明,相同冲击能量下,同种材质撞击物（不同质量）以不同速度冲击复合材料层合板的损伤特性相似;而不同材质撞击物（不同弹性模量和泊松比）得到的结果差异显著. 结合赫兹接触理论,初步解释了撞击物弹性性能影响接触刚度和冲击损伤程度的规律.      

Synthesis of urchin-like Sn–ZnO–C composite and its enhanced electrochemical performance for lithium-ion batteries

Urchin-like Sn–ZnO–C composite have been successfully prepared by thermal annealing of ZnSn(OH)6precursor in acetylene/argon gas(1/9;v/v).The phase of the urchin-like Sn–ZnO–C has been characterized by X-ray diffraction(XRD)and Raman spectrum.The images of scanning electron microscopy(SEM)and transmission electron microscope(TEM)demonstrate that the Sn–ZnO–C composite with an average of 3 lm in diameter is composed of many core–shell nanowires and carbon nanotubes emanated from the center.The thermal annealing temperature and time have crucial effects on the formation of urchin-like structure and carbon content of the Sn–ZnO–C composites.As an anode for lithium-ion batteries,the urchin-like Sn–ZnO–C composite delivers a discharge capacity of 1,034.5 mAh/g in initial cycle and 571.9 mAh/g reversible discharge capacity after 25 cycles at a current density of 50 mA/g.The superior energy storage properties highlight the urchin-like Sn–ZnO–C composite as a potential alternative anode material in lithium-ion batteries.