切断后轴突再生方式和速度的初步研究

目的 建立离体中枢神经系统轴突机械切断模型,观察机械切断后轴突的再生方式和速度. 方法 离体培养新生小鼠皮质神经块,免疫荧光特异染色标记轴突和树突.机械切断轴突建立模型.通过追踪黏附在轴突残段表面细胞点的移动来观察轴突再生方式,并测量再生轴突的生长速度. 结果 (1)在机械切断小鼠皮质神经块轴突后,可见再生轴突从断端长出,分布在轴突残段上的细胞点随着轴突的再生而越过切痕散布到远端.(2)切断组再生轴突在第24,48小时的生长速度分别为(118±32)μm/d、(72±41 )μm/d,而对照组未切断轴突生长速度分别为(41±17)μm/d、(32±19)μm/d. 结论 切断后轴突再生方式是轴突残段生长延伸,而非轴突残端出芽生长,并且切断后再生轴突生长速度快于未切断轴突.     

脊髓损伤后轴突再生抑制分子信号传导的研究进展

为什么周围神经损伤后轴突可以再生并恢复功能,而中枢神经系统(CNS)损伤后却不能再生并留下永久性功能障碍?早在100年前Xajal就观察到:家兔脊髓切断后2 d,近侧端的轴突膨大,第5～6天像发育阶段神经轴突的形成一样,呈管样开始出芽,但很快塌陷,形成球状末端.     

荧光素双标记和电镜观察神经端侧吻合修复神经缺损的实验研究

目的　观察兔耳大神经端侧吻合后轴突再生情况。方法　采用兔耳大神经端侧吻合模型 ,右侧耳大神经作为供神经 ,在适当部位的外膜上纵行切开 2 .0mm(开窗 ) ,左侧耳大神经在近端切断 ,其远侧段作为受神经 ,随机分为 1月组、2月组、4月组和正常对照组。结果　荧光素组 :右侧C2～ 3背根节内可见 3种不同结构的标记细胞 ,即FB(胞浆 )单标记细胞、NY(胞核 )单标记细胞和FB/NY(胞浆 /胞核 )双标记细胞。每组标记细胞数量不同 ,以 2～ 4月间再生较多。FB标记细胞分布广泛 ,大、中、小型细胞均有 ,NY单标记细胞分布区域相对集中。双标记细胞多分布于背根节的中央区。电镜观察组 :受神经术后 1个月 ,距吻合口 0 .5cm之神经 ,有无髓纤维溃变 ,结构紊乱 ,轴突和髓鞘蹦解 ,在溃变有髓纤维髓鞘外偶见再生的较细的无髓纤维 ,2个月时 ,有大量的无髓纤维再生 ,雪旺氏细胞增殖活跃 ,并可见新生的直径细小的有髓纤维 ,髓鞘较薄 ,内部线粒体结构清晰。术后 4个月 ,新生的有、无髓纤维较 2个月时增多 ,以无髓纤维增多显著。结论　神经端侧吻合后轴突可以再生。     

大鼠视神经不完全损伤后自发性再生的实验研究

目的 观察大鼠视神经夹伤后轴突中神经生长相关蛋白-43（GAP-43）的表达变化,探讨大鼠视神经部分损伤后自发性再生的可能性。方法 在眼球后2mm处用反向镊以不同的作用时间夹持视神经,制作不同损伤程度SD大鼠视神经夹伤模型,采用免疫组织化学技术和RT-PCR技术检测损伤后不同时间点GAP-43及其mRNA在受损视神经轴突中的表达。结果 免疫组织化学结果显示,损伤后2个月时轻、中、重组GAP-43表达水平几乎同时达到高峰,轻度损伤组表达水平最高。RT-PCR结果表明,轻、中、重不同损伤组之间及不同恢复时间点的GAP-43mRNA表达水平有差别。结论 大鼠视神经部分（不完全）损伤后存在自发性再生的现象,再生的程度与损伤的程度密切相关。     

神经端侧吻合再生轴突荧光素双标记的实验研究

目的　探讨兔耳大神经端侧吻合后轴突再生的来源 ,及供神经外膜开窗与否对轴突再生的影响。方法　兔耳大神经端侧吻合模型 ,分为A ,B ,C ,D组 ,每组分为 2月、4月、8月 3个时间组 ,动物观察到期后于吻合口远侧供、受神经干分别注入FB ,NY两种荧光素 ,FB注入供神经 ,NY注入受神经。取双侧C2～ 3 背根神经节作冰冻切片 ,荧光显微镜下观察标记情况。结果　 (1)A ,B两组右侧C2～ 3 背根节内分别见FB ,NY单标记细胞和FB/NY双标记细胞 ,标记细胞数量随术后时间的延长增多。 (2 )A ,B两组各时间组神经节内标记细胞数量相无明显差别。结论　 (1)神经端侧吻合后再生轴突来源于供神经的侧枝发芽。 (2 )神经外膜开窗与否对神经轴突再生无明显影响。     

轴突再髓鞘化治疗脊髓损伤的研究进展

脊髓损伤(spinal cord injury,SCI)是常见的中枢神经系统损伤,可以导致患者神经功能障碍.至今临床上尚无有效办法治疗脊髓损伤.目前,关于脊髓损伤治疗的研究集中在减轻脊髓继发性损伤与促进神经组织再生等方面[1].众所周知,髓鞘是神经系统所特有的结构,对维持轴突正常功能及神经冲动传导起着重要作用.轴突脱髓鞘改变是脊髓损伤常见的病理变化.研究显示,脊髓损伤后轴突脱髓鞘变化是影响神经功能恢复的重要原因[1].因此,笔者就目前关于促进轴突再髓鞘化改善脊髓损伤神经功能的相关研究进展进行简要介绍.     

骨髓间充质干细胞对冈田酸致神经细胞损伤的修复作用

目的 观察人骨髓间充质干细胞对冈田酸(OA)损伤的神经细胞是否具有修复作用.方法 应用冈田酸损伤神经母细胞瘤细胞系SH-SY5Y细胞,建立阿尔茨海默病体外模型.将细胞分成正常组、损伤组和治疗组,损伤组用20nmol/L冈田酸损伤24h,治疗组在损伤24h后加入骨髓间充质于细胞的条件培养基治疗24h.采用CCK-8法检测各组细胞活力,免疫荧光染色微管微丝测定细胞树突长度和荧光面积,Western blotting检测磷酸化Tau蛋白和总Tau蛋白含量.结果 冈田酸能损伤SH-SY5Y细胞,使其胞体皱缩、塌陷,出现空泡,树突缩短、断裂,微管微丝排列紊乱,而骨髓间充质干细胞条件培养基可使SH-SY5Y细胞胞体变得圆润,树突重新恢复变长,微管、微丝致密规则,荧光变强;并且能有效降低冈田酸诱导的Tau蛋白过度磷酸化水平.结论 骨髓间充质干细胞对冈田酸损伤的神经细胞具有明显的修复作用.     

周围神经端侧吻合新方法大鼠实验模型的建立

目的 设计制作端侧吻合新方法的动物实验模型，并进行检测。方法实验用Wistar大白鼠，共28只。按拟行神经吻合的方式，将大鼠的左下肢定为实验侧，右下肢定为对照侧。实验侧：切断大鼠左侧胫神经，将胫神经的近断端与腓总神经端侧吻合；对照侧：切断大鼠右侧腓总神经，将腓总神经的远断端与胫神经端侧吻合。3个月后，进行电生理检查，比较两侧固定刺激量的波幅、潜伏期、最大波幅。比较实验侧吻合口远、近端的腓总神经纤维计数。结果实验侧与对照侧相比，波幅、潜伏期、最大波幅差异无统计学意义。实验侧吻合口远侧的神经纤维计数多于近侧神经纤维计数（P〈0．05）。结论端侧吻合新方法的轴突再生机制为胫神经轴突发芽，再生的轴突通过吻合口沿着腓总神经外膜或束膜管道向靶肌肉生长。     

骨髓间充质干细胞移植促进脊髓损伤修复的机制

目的 研究骨髓间充质干细胞(BMSCs)移植对损伤脊髓神经功能恢复的影响及其机制.方法 采用纽约大学脊髓重物坠落仪制作大鼠脊髓损伤模型.脊髓损伤后7d,在损伤中心周围移植BMSCs( BMSCs组)或注射PBS( PBS组).采用BBB评分评价大鼠脊髓功能.测定脊髓空洞体积,透射电镜观察脊髓损伤中心轴突的数量.采用绿色荧光蛋白(GFP)转基因大鼠的BMSCs示踪移植细胞,观察BMSCs移植后在脊髓中的存活及向神经细胞分化的情况.采用脊髓埋管模型,研究BMSCs移植对损伤脊髓轴突再生的影响.结果 BMSCs组BBB评分显著高于PBS组,而其脊髓空洞体积明显小于PBS组.电镜下可见,在脊髓损伤中心BMSCs组的轴突数量明显多于PBS组.细胞移植后4周,在脊髓损伤中心周围可见大量BMSCs - GFP细胞.免疫荧光染色结果表明,脊髓移植的BMSCs并不表达神经元、星形胶质细胞和少突胶质细胞的表面标志性蛋白.脊髓埋管实验发现,在种有BMSCs的导管内可见有NF阳性的神经纤维的长入,而未种有BMSCs组的导管内未见神经纤维的生长.结论 脊髓损伤后进行BMSCs移植可促进损伤脊髓功能的恢复,其机制与BMSCs移植促进神经元轴突再生的作用有关.     

脊髓损伤再生与修复的研究进展

脊髓损伤 (ｓｐｉｎａｌｃｏｒｄｉｎｊｕｒｙ ,ＳＣＩ)后的中枢神经再生 ,一直是生物医学界研究的前沿课题 ,尤其近10余年来进展较快 ,综述如下。1　影响中枢神经轴突再生的因素1 1　中枢神经再生的抑制性环境　 1981年 ,Ｄａｖｉｄ等[1] 研究证明 ,成年大鼠中枢神经细胞的轴突有能力再生 ,前提是必须为其提供有利的环境。在未损伤的中枢神经中 ,轴突与星形胶质细胞和少突胶质细胞相接触。ＳＣＩ后 ,发生了创伤性细胞反应 ,星形胶质细胞分裂 ,并衍化为“瘢痕性”胶质细胞 ;微胶质细胞和原始少突胶质细胞增殖并移向损伤区。中枢神经损伤区存…     

Knee injury and Osteoarthritis Outcome Score (KOOS) - validation of a Swedish version

The Knee injury and Osteoarthritis Outcome Score (KOOS) is a self-administered instrument measuring outcome after knee injury at impairment, disability, and handicap level in five subscales. Reliability, validity, and responsiveness of a Swedish version was assessed in 142 patients who underwent arthroscopy because of injury to the menisci, anterior cruciate ligament, or cartilage of the knee. The clinimetric properties were found to be good and comparable to the American version of the KOOS. Comparison to the Short Form-36 and the Lysholm knee scoring scale revealed expected correlations and construct validity. Item by item, symptoms and functional limitations were compared between diagnostic groups. High responsiveness was found three months after arthroscopic partial meniscectomy for all subscales but Activities of Daily Living.     

Endovascular management of carotid-cavernous fistulas

Objective To investigate endovascular treatment of traumatic direct carotid-cavernous fistulas （CCF） and their complications such as pseudoaneurysms. Methods： Over a five-year period, 22 patients with traumatic direct CCFs were treated endovascularly in our institution. Thirteen patients were treated once with the result of CCF occluded, 8 twice and 1 three times. Treatment modalities included balloon occlusion of the CCF, sacrifice of the ipsilateral internal carotid artery with detachable balloon, coll embolization of the cavernous sinus and secondary pseudoaneurysms, and covered-stem management of the pseudoaneurysms. Results All the direct CCFs were successfully managed endovascularly. Four patients developed a pseudoaneurysm after the occlusion of the CCF with an incidence of pseudoaneurysm formation of 18.2% （4/22）. A total number of 8 patients experienced permanent occlusion of the ICA with a rate of ICA occlusion reaching 36.4% （8/22）. Followed up through telephone consultation from 6 months to 5 years, all did well with no recurrence of CCF symptoms and signs. Conclusion Traumatic direct CCFs can be successfully managed with endovascular means. The pseudoaneurysms secondary to the occlusion of the CCFs can be occluded with stent-assisted coiling and implantation of covered stents.     

The acutely limping child

Acute limping may be the result of multiple pathologies in children. The differential diagnosis varies based on the age of the child. Irrespective of age, the initial imaging work-up includes AP and frog leg radiographs of the pelvis and ultrasound; MRI may sometimes be helpful. In children less than 3 years, infections and trauma are most frequent. MRI is the imaging modality of choice when osteomyelitis is clinically suspected. Between the ages of 3 and 10 years, transient synovitis of the hip and Legg-Calvé-Perthes disease are main considerations but infection, inflammation and focal bony lesions are also considered. In children over 10 years, slipped capital femoral epiphysis also is considered.     

Do Balance Board Training Programs Reduce the Risk of Ankle Sprains in Athletes?

Introduction Ankle sprains are the most common musculo-skeletal injury that occurs in athletes,particularly in sports that require jumping and landing on one foot such as soccer,and basketball(1-4).These injuries often result in significant time loss from participation,long-term disability,and have a major impact on health care costs and resources(5-8).     

High Intensity Interval Training:New Insights

KEY POINTS ·High-intensity interval training(HIT)is characterized by repeated sessions of relatively brief，intermittent exercise.often performed with an“a11 out”effort or at an intensity close to that which elicits peak oxygen uptake(i.e.，≥90%of VO2 peak).     

Developmental validation of the PowerPlex(®) ESI 16 and PowerPlex(®) ESI 17 Systems: STR multiplexes for the new European standard

In response to the ENFSI and EDNAP groups’ call for new STR multiplexes for Europe, Promega^® developed a suite of four new DNA profiling kits. This paper describes the developmental validation study performed on the PowerPlex^® ESI 16 (European Standard Investigator 16) and the PowerPlex^® ESI 17 Systems. The PowerPlex^® ESI 16 System combines the 11 loci compatible with the UK National DNA Database^®, contained within the AmpFlSTR^® SGM Plus^® PCR Amplification Kit, with five additional loci: D2S441, D10S1248, D22S1045, D1S1656 and D12S391. The multiplex was designed to reduce the amplicon size of the loci found in the AmpFlSTR^® SGM Plus^® kit. This design facilitates increased robustness and amplification success for the loci used in the national DNA databases created in many countries, when analyzing degraded DNA samples. The PowerPlex^® ESI 17 System amplifies the same loci as the PowerPlex^® ESI 16 System, but with the addition of a primer pair for the SE33 locus. Tests were designed to address the developmental validation guidelines issued by the Scientific Working Group on DNA Analysis Methods (SWGDAM), and those of the DNA Advisory Board (DAB). Samples processed include DNA mixtures, PCR reactions spiked with inhibitors, a sensitivity series, and 306 United Kingdom donor samples to determine concordance with data generated with the AmpFlSTR^® SGM Plus^® kit. Allele frequencies from 242 white Caucasian samples collected in the United Kingdom are also presented. The PowerPlex^® ESI 16 and ESI 17 Systems are robust and sensitive tools, suitable for the analysis of forensic DNA samples. Full profiles were routinely observed with 62.5 pg of a fully heterozygous single source DNA template. This high level of sensitivity was found to impact on mixture analyses, where 54–86% of unique minor contributor alleles were routinely observed in a 1:19 mixture ratio. Improved sensitivity combined with the robustness afforded by smaller amplicons has substantially improved the quantity of data obtained from degraded samples, and the improved chemistry confers exceptional tolerance to high levels of laboratory prepared inhibitors.