大鲵皮肤黏液的抗氧化性及安全性评价研究

为研究大鲵皮肤黏液的抗氧化性及急毒性安全性评价,利用邻苯三酚自氧化法和DPPH法,测定了大鲵黏液对超氧阴离子自由基(O-·2)及DPPH自由基的清除率;通过对小鼠灌胃饲养实验检测大鲵皮肤黏液的急毒性,并采用气质联用色谱分析黏液中的毒性成分。结果显示:大鲵黏液对超氧阴离子自由基的清除率为6.77%,对DPPH自由基的清除率为90.25%;大鲵黏液全粉的LD50值为4.64 g/kg,毒性成分为二甲基二硫醚(C2H6S2)。表明大鲵黏液具有抗氧化性和低毒性,经脱毒后可开发为保健产品。     

中国大鲵胚胎发育形态特性比较研究

通过观察在全人工繁育条件下大鲵的胚胎发育及器官的形成过程,对比仿天然生态养殖的大鲵胚胎发育过程,对大鲵从受精卵到孵化为幼苗出膜进行了连续系统的形态学观察.结果发现:人工繁育的大鲵在胚胎发育至神经胚期和器官形成期,有明显的"神经沟出现"、"视泡形成"和"心脏跳动"的特征,因而在传统分期的基础上增加了"神经沟期"、"视泡形成期"和"心脏跳动期",从而将大鲵的胚胎发育过程细化为23个时期;虽然同种大鲵的人工繁育和仿生态养殖方式绝大部分发育时期的外形特征基本相同,但在卵裂期和神经胚期依旧存在差异;并利用人工繁育技术,提高其孵化率,为进一步研究大鲵的人工繁育提供理论基础和实验材料.     

中国大鲵复合体谱系多样性及贵州分布中国大鲵的分类评估

为探索新生代地质构造演化在塑造贵州及周边地区地质景观过程中,对现存动物分布模式的影响,选择中国大鲵复合体Andrias davidianus comlex作为研究物种,以线粒体基因组作为分子标记,探讨中新世地质构造事件对于中国大鲵复合体的系统发育和谱系分化。系统发育分析表明:在中国大鲵复合体中,有与地理区域相关的7个主要谱系(A-G),其中谱系C和谱系G分别被描述为华南大鲵A.sligoi(Boulenger, 1924)和中国大鲵A.davidianus(Blanchard, 1871),且贵州分布的大鲵在系统发育上应归属于华南大鲵。分歧时间表明:中国大鲵谱系与日本大鲵A.japonicus(Temminck, 1836)与青藏高原中新世早期的隆升有关;中国大鲵复合体谱系B至谱系G在8.9～12.8 Ma的分化与中新世晚期青藏高原的强烈隆升和中新世晚期气候变暖期间有关;中新世早期的寒冷时期,全球海平面的下降以及东海陆架盆地的地理构造变化,在台湾-日本岛屿与亚洲大陆之间可能已跨海形成陆桥廊道,为日本大鲵从华南地区扩散到亚洲大陆提供了可能。研究认为,小区域范围内的造山运动及其引发的水系形成或改道和中新世中晚期古气候的波动是导致中国大鲵谱系多样化的主要原因。     

中国大鲵的繁殖生态暨行为学观察研究

在秦岭地区天然水域大鲵简易繁苗法和仿生态亲鲵培育池繁苗的基础上,论述了促成大鲵繁苗的8项生态因子．秦岭地区大鲵繁育日度与江汉平原区存在较大差异;大鲵在不同产区繁殖期和繁殖盛期的时间,建议各地应抓住当地的繁殖时机做好繁苗工作．记述了大鲵在催情效应期亲吻、顶腹、嬉戏、交尾等繁殖行为．对大鲵繁殖配组的性比、繁殖日度、繁殖时间、雌雄性腺发育同步等问题进行了讨论．     

中国大鲵皮肤的组织学观察

本文研究了中国大鲵皮肤的组织学结构,结果表明:(1)中国大鲵皮肤存在着丰富的皮肤呼吸结构。(2)中国大鲵皮肤上的疣瘤在头部的背面及腹面构成特定图形,这是其特有的。(3)同爬行类的鳄蜥相比较,中国大鲵皮肤结构仍呈以水生为主的特性。     

温度对禁食大鲵碳氮代谢的影响

本文研究温度对禁食大鲵碳代谢和氮代谢的影响,结果表明:随着温度的升高,禁食大鲵的碳代谢和氮代谢均上升,其代谢率升高;禁食大鲵的代谢率很低,15℃时,每日每公斤体重的蛋白质消耗为0.7g左右,从理论上证明大鲵的耐饥饿能力很强;雄性大鲵比雌性大鲵的代谢率稍高。     

基于近红外光谱的大鲵黏液粉掺伪的定性定量研究

采用近红外光谱扫描不同掺伪样品,用偏最小二乘线性判别法分别建立掺伪大鲵黏液粉的2分类(纯大鲵黏液粉和掺伪样品)和5分类(纯大鲵黏液粉、掺入土豆淀粉、大鲵肉粉、大鲵蛋白粉和大鲵皮粉)定性判别模型;用偏最小二乘回归分别建立4类掺伪大鲵黏液粉的定量校正模型。结果表明,原始光谱经一阶导数+标准变量变换预处理后,所建2分类和5分类小二乘线性判别定性模型的校正集和预测集均无误判数;大鲵黏液粉掺入土豆淀粉、大鲵肉粉、大鲵蛋白粉和大鲵皮粉的定量预测模型能够较好地验证黏液掺伪成分。     

中国大鲵繁殖前期夜间活动节律及其与环境因子的关系

采用全事件记录法,2011年7—8月对秦岭南坡仿生态环境下养殖的中国大鲵繁殖前期夜间活动节律及影响其出洞活动的环境因子进行了研究.结果表明:每天19:30大鲵开始出洞活动,21:30至次日凌晨1:30为出洞活动高峰期,6:30后返回洞穴;雌性和雄性成鲵的夜间活动数量存在显著差异,成体与亚成体的夜间活动数量无显著差异;在不同天气条件下,大鲵出洞活动的数量与水温、光照强度的相关性较强;当光照强度在685～1 431lx、相对光照强度为3%时大鲵开始出洞活动或回洞隐藏,而当光照强度降至0lx后约2h、水温在17.1～18.4℃时出洞活动达到高峰期.表明在繁殖前期大鲵夜间活动节律同时受光照和水温的影响,光照强度是控制大鲵出洞活动的关键因子,水温是决定其出洞活动高峰期的主要因子.     

中国大鲵（Andrias davidianus）的胚胎发育

对中国大鲵(Andrias davidianus)胚胎发育过程的外部形态及器官发育特点进行了详细地描述,为中国大鲵胚胎发育制定出完整的分期标准.中国大鲵胚胎发育过程依据形态学和组织学特征可以划分为6个阶段:卵裂阶段、囊胚阶段、原肠胚阶段、神经胚阶段、器官形成阶段、孵化阶段,共20个时期.从整体上来看,中国大鲵的胚胎发育特征与东方蝾螈(Cynops orientalis)、黑斑蛙(R.nigromaculata)大体相似,主要的差异表现在早期卵裂方式以及消化系统的发育方面.形态学及组织学观察表明,中国大鲵卵裂并非盘状卵裂类型.同时,中国大鲵胚胎发育过程中前三次卵裂均为经裂,胚胎消化系统的发生发育迟缓,无平衡器或口吸盘等,这些均为中国大鲵胚胎发育的显著特点.     

铜离子对中国大鲵幼体的胁迫效应

为研究铜离子暴露对中国大鲵的毒性效应,以中国大鲵幼体为研究对象,采用慢性染毒法,将大鲵幼体暴露于0mg/L、1.0mg/L、1.5mg/L和3.0mg/L的铜溶液中30d,观察铜离子胁迫下的大鲵幼体临床症。之后立即对大鲵幼体进行解剖并观察其皮肤、肝脏、胰脏和小肠组织的病理变化,同时采集大鲵幼体的皮肤、肝脏、胰脏和小肠,利用石蜡切片和HE染色对大鲵幼体的组织病理损伤进行观察。结果表明,随着铜离子浓度的增加,大鲵幼体异常行为与其体表黏液的分泌也越加频繁;铜离子胁迫会导致大鲵幼体膀胱显著膨大并充斥大量尿液;铜离子对大鲵幼体皮肤的真皮结构、肝脏和胰脏细胞会产生一定的病理损伤,但对大鲵幼体皮肤、肝脏、胰脏和小肠组织结构未造成毒害效应。本研究表明,铜离子胁迫30d后会对大鲵幼体产生一定的毒性效应,并且毒性程度与铜离子的浓度呈正相关关系。     

Tropic1808基因重组蛋白对损伤坐骨神经脊髓细胞凋亡的影响

探讨Tropic1808基因重组蛋白对损伤坐骨神经的新生大鼠脊髓细胞凋亡影响,将新生SD大鼠一侧坐骨神经切断后,用无菌止血海绵包裹断离的神经近侧端,海绵内加入Tropic1808基因重组蛋白,阳性用神经生长因子、阴性用生理盐水作为对照;术后3、6、12h经TUNEL法染色,在光镜、电镜和图像分析系统下,了解L4－L5段脊髓细胞凋亡情况。得到生理盐水组的脊髓出现大量绸亡细胞;Tropic1808基因重组蛋白组凋亡细胞数量较生理盐水组显减少;Tropic1808基因重组蛋白组与神经生长因子组之间凋亡细胞数量的差别无显性意义。说明Tropic1808基因重组蛋白有保护受损神经组织,减少细胞凋亡的作用。     

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.     

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.     

Neural stem cell transplantation in the repair of spinal cord injury

Neural stem cells are a pronising candidate for neural transplantation aimed at neural cell replacement and repair of the damaged host central nervous system (CNS). Recent studies using neural stem cells have shown that implanted neural stem cells can effectively incorporate into the damaged CNS and differentiate into neurons, astrocytes, and oligodendrocytes. The recent explosion in the field of neural stem cell research has provided insight into the inductive factors influencing neural stem cell differentiation and may yield potential therapies for several neurological disorders, including spinal cord injury. In this review, we summarize recent studies involving neural stem cell biology in both rodents and humans. We also discuss unique advantages and possible mechanisms of using neural stem cell trans plantation in the repair of spinal cord injury.     

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.     

Clonal selection drives genetic divergence of metastatic medulloblastoma

Medulloblastoma, the most common malignant paediatric brain tumour, arises in the cerebellum and disseminates through the cerebrospinal fluid in the leptomeningeal space to coat the brain and spinal cord. Dissemination, a marker of poor prognosis, is found in up to 40% of children at diagnosis and in most children at the time of recurrence. Affected children therefore are treated with radiation to the entire developing brain and spinal cord, followed by high-dose chemotherapy, with the ensuing deleterious effects on the developing nervous system. The mechanisms of dissemination through the cerebrospinal fluid are poorly studied, and medulloblastoma metastases have been assumed to be biologically similar to the primary tumour. Here we show that in both mouse and human medulloblastoma, the metastases from an individual are extremely similar to each other but are divergent from the matched primary tumour. Clonal genetic events in the metastases can be demonstrated in a restricted subclone of the primary tumour, suggesting that only rare cells within the primary tumour have the ability to metastasize. Failure to account for the bicompartmental nature of metastatic medulloblastoma could be a major barrier to the development of effective targeted therapies.     

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.     

基因重组碱性成纤维细胞生长因子对大鼠脊髓损伤神经保护作用

目的 :探索碱性成纤维细胞生长因子 (bFGF)对大鼠脊髓损伤的神经保护作用 方法 :将吸入bFGF的胶原蛋白海绵或空白海绵贴敷于大鼠脊髓损伤处 ,术后 1、2、3周 ,对大鼠机能进行评分 ,并对大脑运动皮质进行电镜观察分析 结果 :术后 1、2、3周 ,bFGF组大鼠运动评分均明显优于对照组 (Ρ <0 .0 5) ,运动皮质电镜结果显示bFGF组线粒体、内质网轻度肿胀 ,神经毡结构正常 ,无明显胶质细胞增生 程度较对照组明显减轻 结论 :bFGF对大鼠脊髓受损神经纤维起源脑区—运动皮质的神经细胞具有明显的保护作用 ,进而使大鼠运动功能受损明显减轻     

Chemotropic guidance of developing axons in the mammalian central nervous system

In the developing nervous system, axons project considerable distances along stereotyped pathways to reach their targets. Axon guidance depends partly on the recognition of cell-surface and extracellular matrix cues derived from cells along the pathways. It has also been proposed that neuronal growth cones are guided by gradients of chemoattractant molecules emanating from their intermediate or final cellular targets. Although there is evidence that the axons of some peripheral neurons in vertebrates are guided by chemotropism and the directed growth of some central axons to their targets is consistent with such a mechanism, it remains to be determined whether chemotropism operates in the central nervous system. During development of the spinal cord, commissural axons are deflected towards a specialized set of midline neural epithelial cells, termed the floor plate, which could reflect guidance by substrate cues or by diffusible chemoattractant molecules. Here we provide evidence in support of chemotropic guidance by demonstrating that the rat floor-plate cells secrete a diffusible factor(s) that influences the pattern and orientation of commissural axon growth in vitro without affecting other embryonic spinal cord axons. These findings support the hypothesis that chemotropic mechanisms guide developing axons to their intermediate targets in the vertebrate CNS.     

网球发球技术与腰背损伤关系的生物力学分析

为探讨网球发球技术与腰背损伤之间的关系,探寻导致腰背损伤的技术性原因,采用三维高速摄像法和图像解析法,以健康业余网球运动员为对照,对患有腰背部损伤业余网球运动员发球技术进行对比分析。结果表明搔背期末躯干扭转过大可能是造成业余网球运动员腰背损伤的直接原因,腰腹肌力量素质较差和抛球较偏是导致这一问题的主要技术性因素,并针对这些问题提出相应的解决办法,供教练员和业余运动员参考。