Ang-(1-7)与肺高压状态下肺血管平滑肌细胞的增生*☆

背景：Ang-(1-7)虽然具有抗血管平滑肌细胞增殖作用,但在不同的血管床中其作用可能存在差异。直接给予外源性Ang-(1-7)是否可抑制肺动脉高压大鼠肺血管平滑肌细胞的增殖尚不清楚。 目的：探讨Ang-(1-7)对野百合碱诱导的肺动脉高压大鼠肺血管平滑肌细胞增殖的影响。 方法：雄性SD大鼠颈部一次性注射60 mg/kg野百合碱制备肺动脉高压模型。24 h后,分别经微泵持续泵入Ang-(1-7)(治疗组)或生理盐水(模型组),并设立未造模的对照组。给药2,4周,测定大鼠的右心室收缩压、心室质量、肺小动脉管壁厚度占管径的百分比及管壁面积占血管总面积的百分比。免疫组织化学方法检测肺血管平滑肌细胞α-平滑肌肌动蛋白及增殖细胞核抗原的表达。 结果与结论：野百合碱诱导2周,与对照组比较,模型组大鼠右心室收缩压、各心室的质量无明显变化,肺小动脉管壁厚度占管径的百分比、管壁面积占血管总面积的百分比、增殖细胞核抗原阳性率显著增高,α-平滑肌肌动蛋白显著降低;野百合碱诱导4周,模型组大鼠右心室收缩压、各心室的质量、肺小动脉管壁厚度占管径的百分比、管壁面积占血管总面积的百分比、增殖细胞核抗原阳性率均显著增高,α-平滑肌肌动蛋白显著降低。而治疗组上述指标与对照组比较差异无显著性意义 (P > 0.05)。说明在野百合碱诱导的肺动脉高压模型中,在肺动脉压增高之前已有肺血管形态学的变化,Ang-(1-7)可通过减轻肺血管平滑肌细胞的增生抑制大鼠肺动脉压的升高。     

肺动脉高压动物模型的理论研究及其制备特点

背景：建立肺动脉高压动物模型，对其深入研究有助于推动临床对肺动脉高压诊治水平的不断提高。 目的：总结与探讨各种肺动脉动物模型的制备、病理生理学特点以及对临床肺动脉高压的模拟性。 方法：应用计算机检索PubMed数据库1975-01/2009-09期间相关文章,检索词为“pulmonary hypertension 、animal model”，同时检索中国期刊全文数据1990-01/2009-09期间的相关文章，检索词为“肺动脉高压，动物模型”。 纳入外科手术制作肺动脉高压动物模型的研究、药物注射制作肺动脉高压动物模型的研究、有新生内膜形成的肺动脉高压动物模型研究、肺动脉高压动物模型与临床肺动脉高压患者的病理生理对比的研究、肺动脉高压动物模型的药物干预研究。 结果与结论：已知的肺动脉高压动物模型建立方法包括.外科手术建立分流术、野百合碱注射、低氧吸入法等经典方法，以及近年报道的几种有新生内膜产生的重度肺动脉高压模型。此类模型建立经过了不断地改进,为了解肺动脉高压的细胞及分子病理学机制提供了帮助, 但尚不明确这些模型能在多大程度模拟临床肺动脉高压的细胞和分子发生机制，因此仍不清楚哪类模型更能代表临床肺动脉高压的病理机制。     

应用左向右分流建立大鼠慢性肺动脉高压模型及其特征

背景：应用左向右分流大鼠模型可以研究慢性肺血管重构在成人型先天性心脏病中的发病机制。 目的：观察慢性左向右分流大鼠模型慢性肺动脉高压形成的特点。 设计、时间及地点：随机对照动物实验,于2008-04/2009-04 在解放军第三军医大学新桥医院动物实验中心完成。 材料：4周龄SPF级纯系健康SD大鼠80只,体质量95~110 g。随机分为对照组、分流组,每组40只。自制改良聚乙烯血管连接套管,近心端内外径分别为0.6 mm和 0.8 mm,远心端内外径分别为0.8 mm和 1.0 mm,长1.6 mm。 方法：分流组大鼠：行左向右分流术,运用收缩型聚乙烯血管连接器建立右颈总动脉-颈外静脉连接。对照组行假手术。手术后在第4,8,12,16周（每个时相点10 只大鼠),通过血流动力学检查、病理标本制作、苏木精-伊红染色、图像分析等一系列步骤对该模型进行评价。 主要观察指标：分流组和对照组大鼠右室收缩压、右心肥大比率[右室/（左室＋室间隔）],各级肺小动脉相对中膜厚度改变。 结果：全部实验动物存活。分流组肺循环血流量明显高于对照组(P < 0.01)。与对照组相比,分流12,16周右室收缩压明显增高(P < 0.01),分流12,16周时右心肥大比率显著增加(P < 0.01)。与对照组相比,分流12周和16周组肺动脉相对中膜厚度明显增加 (P < 0.01)。 结论：左向右的持续低分流,能有效引起慢性肺血管重构,颈总动脉-颈外静脉连接建立慢性肺动脉高压模型操作简便,稳定性好,对实验动物损伤小,是研究低分流引起的慢性肺动脉高压形成的有用工具。 关键词：肺动脉高压;慢性;大鼠;特征     

袖套法建立大鼠肺移植模型的手术技巧

背景：建立大鼠肺移植动物模型是研究肺移植后病理生理过程及其治疗的基础和关键,但因其需要精细外科技术,难度较大,限制了这一模型的应用。 目的：探讨袖套法建立稳定的大鼠肺移植模型的手术操作技巧。 方法：纳入60只大鼠,采用改良的三袖套技术建立大鼠左肺原位移植模型30例。供肺植入血管、支气管套接吻合的技巧：受体肺静脉采用90°角分布的“4针悬吊法”,使塌陷的静脉血管开口完全张开且方向固定,减少受体静脉干短拙或强行套入导致血管壁撕裂的可能。受体肺动脉采用120°角分布的“3针悬吊”兜开,套接时应注意供肺套管的方向。最后支气管采用内支架吻合。计算各阶段手术时间及移植成功率。 结果与结论：30例大鼠肺移植手术成功率为90%,移植后存活率100%,左供肺摘取需时(3±1) min,供肺完成体外套管时间分别为：肺动脉(2.0±0.5) min、肺静脉(3±1) min、支气管(2.0±0.5) min,供受体动静脉和支气管套管吻合时间分别为：肺动脉(4±1) min、肺静脉(8±3) min、支气管(2.0±0.5) min,总手术时间(55±10) min。提示改良的三袖套技术建立大鼠肺移植模型操作简便,手术成功率高,可为大鼠肺移植缺血再灌注损伤研究提供稳定可靠的动物模型。     

慢性肺动脉栓塞实验动物模型构建的技术进展

目的：综述国内外关于慢性血栓栓塞性肺动脉高压(chronic thromboembolism pulmonary hypertension, CTEPH )实验动物模型构建技术的研究概况。 方法：应用计算机检索PubMed数据库2006/2009相关文章,检索词为“model of pulmonary thromboembolism”。同时计算机检索中国期刊全文数据库2003/2009相关文章,检索词为“肺动脉栓塞,实验”。此外还手工查阅相关专著数部。纳入标准：①文章所述内容应与CTEPH实验研究相关,包括慢性血栓栓塞性肺动脉高压流行病学,不同实验动物及不同制备方式。②同一领域选择近期发表或在权威杂志上发表的文章。排除标准：①重复研究。②Meta分析。 结果与结论：目前用于CTEPH模型制备的实验动物主要有犬、猪和鼠等。很多研究者都尝试模仿深静脉血栓形成后,多次急性肺栓塞事件所导致的CTEPH形成机制,建立CTEPH验动物模型。建立犬CTEPH模型主要有反复自体血凝块注入法及陶瓷念珠输入法,可用于CTEPH病理生理特点、数字剪影检查、解剖研究以及肺动脉内膜剥脱手术和介入治疗等干预治疗血栓栓塞性肺动脉高压的研究与影像学诊断技术的研究。建立猪CTEPH模型主要采用体外注入栓子法,可用于影像技术诊断CTEPH研究。建立鼠CTEPH模型主要采用反复自体血凝块注入法与肺动脉结扎法,可用于CTEPH病理生理及诊断方面研究。目前对CTEPH的研究主要是使用犬、猪和鼠实验动物模型,各有优缺点,在具体的实验研究中需根据实验目的和设计选择适当的实验动物及制作方法,以便取得最佳的实验结果。     

β淀粉样蛋白1-40和氯化铝双干预阿尔茨海默病大鼠模型的建立

背景：目前已建立的各种阿尔茨海默病动物模型均存在一定的局限性。 目的：以β淀粉样蛋白1-40和氯化铝双干预的方式,建立一种较为理想而实用的阿尔茨海默病大鼠模型。 方法：健康雄性老年SD大鼠,经Morris水迷宫训练和筛选后,随机分为模型组、生理盐水组和对照组。采用单侧侧脑室一次性注射β淀粉样蛋白1-40和腹腔连续4周隔天注射3%氯化铝的方式建立阿尔茨海默病大鼠模型。以Morris水迷宫实验和跳台实验检测模型大鼠的行为学变化。以刚果红和苏木精-伊红染色检测大鼠海马淀粉样蛋白沉积以及病理学改变。 结果与结论：与对照组及生理盐水组相比,模型组大鼠水迷宫实验逃避潜伏期明显延长(P < 0.05);跳台实验反应时间、基础错误次数和错误次数显著增加(P < 0.05),潜伏期明显缩短(P < 0.05)。模型组大鼠海马可见淀粉样蛋白物质沉积,细胞形态发生明显的损伤改变且细胞数量减少。以上结果提示,以β淀粉样蛋白1-40和氯化铝双干预的方式能够成功复制出一种比较理想而实用的阿尔茨海默病大鼠模型。     

改良三套管法建立大鼠左肺原位移植模型

背景：肺移植是治疗终末期肺部疾病的惟一方法。建立肺移植动物模型是肺移植基础研究的首要条件。 目的：建立一种简便、稳定和有效的同种大鼠异体左肺原位移植模型。 方法：50只雄性SD大鼠随机分为供体以及受体,采用改良三套管法进行大鼠左肺原位移植。首先完成供肺制备,并将供肺置于受体原左肺上方并保持供肺于4 ℃ LPD液环境中。按照左肺动脉-左肺静脉-左肺支气管的顺序依次完成供肺与受体相应结构的吻合。然后依次开放左肺静脉-肺动脉,调整潮气量,离断受体原左肺。观察手术成功率、手术时间,5周后对受体行血气分析。 结果与结论：手术成功率92%,手术时间为(55±3) min,术后存活均达5周。5周后阻断右肺门15 min前、后左肺静脉取血,血气分析差异无显著性意义(P > 0.05)。提示新改良的三套管法是一种简便稳定有效的大鼠原位左肺移植模型。     

门静脉高压征模型大鼠构建及门静脉侧支血管和内脏血管的形成

背景：Apelin/APJ系统在心血管调节中具有降低血压、加强心脏收缩及Apelin刺激血管生成等作用已为人们所证实。 目的：确认apelin和APJ在内脏组织中的表达,及检验apelin在门脉高压征大鼠的内脏新生血管发育、内脏充血及门静脉侧支化中的关联作用。 方法：36只大白鼠随机分为模型组18只和假手术组18只,模型组采用局部门静脉结扎构建门脉高压征大鼠模型,腹腔注射生理盐水或特定Apelin受体拮抗剂F13A。假手术组除不行结扎外,其余同模型组。 结果与结论：Apelin及其受体APJ在门静脉高压征的大鼠内脏血管系统过度表达。F13A在门静脉高压征的大鼠中能有效减少内脏血管再生和减少血管内皮生长因子、血小板衍生生长因子和血管生成素2的表达,也能减少门静脉侧支血管的形成。     

改良Heron法的同种异体心脏移植模型建立

背景：啮齿类动物心脏移植模型分为工作模型和非工作模型,非工作模型相对于工作模型,手术时间短、成功率高,其中以Heron法最为显著。 目的：对Heron法建立大鼠心脏移植模型的手术方法进行改良,建立更合理、符合实验需要的心脏移植模型,以利于后续实验研究。 方法：对Heron法进行改良,将受体右颈外静脉套管插入供心右肺动脉,右颈总动脉套管插入供心主动脉,环扎固定,供心左肺动脉结扎,从而快速、高效地建立改良的心脏移植模型。观察大鼠移植成功率、并发症、总手术时间、受体血管套管准备时间,供心摘取时间,颈部移植时间及供心冷缺血时间。 结果与结论：单人操作连续进行正式实验25次,移植成功24次,成功率96%。全组无吻合口漏血、血液回流障碍,术后受体无死亡。每例手术总时间需50~60 min;受体血管套管准备时间为(18±3) min;供心摘取时间为(10±1) min;颈部移植时间为(6±1) min;冷缺血时间为(16±1) min。结果表明,改良Heron法建立心脏移植模型,无需显微外科操作,是一种冷缺血时间短,更合理、实用、稳定可靠和易于复制的器官移植研究动物模型。     

干细胞移植联合血管内皮生长因子对门静脉高压症大鼠腹膜后交通支形成的影响

背景：研究表明新生血管生成需要内皮细胞和血管生长因子的共同参与。骨髓单个核细胞中的CD34细胞在缺血组织中能分泌多种血管生长因子，可促进新生血管生成。 目的：观察骨髓单个核细胞移植联合血管内皮生长因子能否促进门静脉高压症大鼠腹膜后交通支循环的形成。 设计、时间及地点：随机区组，动物对照观察，于2007-01/04在河南省动物实验中心完成。 材料：清洁级雄性SD大鼠57只，10只用于分离制备骨髓单个核细胞，剩余47只随机分为5组：正常组7只、模型对照组10只、干细胞移植组10只、血管内皮生长因子组10只、联合组10只。血管内皮生长因子为美国Peprotech 公司产品。 方法：除正常组外，其余4组大鼠均建立肝前性门脉高压模型。模型对照组在结扎点以下左侧靠近脊柱的后腹膜沿下腔静脉选取5个注射点，每点注射0.1 mL生理盐水，逐层关腹，常规培养3个月；干细胞移植组每点注射等量骨髓单个核细胞悬液；血管内皮生长因子组每点注射等量稀释后的血管内皮生长因子；联合组每点注射等量骨髓单个核细胞悬液，并紧靠注射点位置注射等量稀释后的血管内皮生长因子。 主要观察指标：门静脉压力及腹膜后交通支造影血流状况。免疫组化技术检测微血管密度。 结果：各组门静脉压力及侧支血管数均基本相似（F=0.313，P > 0.05；F=1.076，P > 0.05）。各组微血管数量比较差异有显著性意义（F=11.756，P < 0.05），微血管密度为联合组>干细胞移植组=血管内皮生长因子组>模型对照组。 结论：异体骨髓干细胞移植及血管内皮生长因子注射均可促进门静脉高压大鼠腹膜后血管的形成，且二者联合可有效缓解门静脉压力。     

聚乳酸聚羟基乙酸共聚物三维神经导管修复周围神经缺损

背景：异体神经移植由于存在难以消除的宿主免疫排斥反应,限制了其使用,许多学者试图用其他组织替代来弥补以上不足,但效果均不满意。目前,尚没有研制出公认的效果满意的人工神经,自体神经移植至今仍被认为是最佳选择。 目的：观察聚乳酸聚羟基乙酸共聚物(PLGA,85∶15)三维神经导管修复大鼠周围神经缺损的可行性,及神经导管内微丝支架的作用和不同数量微丝对神经再生的影响。 方法：40只成年SD大鼠随机数字表法分为4组,制作大鼠12 mm的左侧坐骨神经缺损模型,用该导管桥接大鼠12 mm的坐骨神经缺损。A组：PLGA神经导管组;B组：PLGA神经导管内纵形放入20根PLGA微丝;C组：PLGA神经导管内纵形放入40根PLGA微丝;D组：自体神经移植组。A、B、C组神经导管内均注入层粘蛋白+神经生长因子混合液。造模后动态观察大鼠肌肉萎缩、跛行情况,测量神经导管内再生神经的传导速度、小腿三头肌湿质量恢复率。对再生神经中1/3段行组织学观察及图像分析以评价神经修复的效果。 结果与结论：造模后各组再生神经均已通过神经导管长入远端,B、D组再生神经较A、C组粗大;再生神经的运动神经传导速度B组和D组明显快于A组和C组(P < 0.05);A组、C组肌肉萎缩最明显,而B组、D组肌肉萎缩较轻且肌肉萎缩程度基本相当。病理图像分析神经纤维计数以D组最多,B组次之,而与A组、C组相比差异均有显著性意义(P < 0.05),B组与D组的再生神经纤维数量及成熟程度均要明显优于A组和C组。提示新型的PLGA三维神经导管能有效引导SD大鼠坐骨神经长过12 mm的神经缺损,是一种较理想的神经导管;神经导管内微丝支架能有效引导神经再生,数量过多反而可能抑制神经再生。     

纤维蛋白凝胶携载血管内皮生长因子对大鼠损伤坐骨神经运动功能的影响

背景：坐骨神经损伤后的修复方法多样,但由于坐骨神经解剖和功能上的特殊性,神经功能的恢复仍不理想。 目的：观察局部应用纤维蛋白凝胶携载血管内皮生长因子,对损伤坐骨神经组织神经功能恢复的疗效。 方法：将Wistar大鼠左侧坐骨神经切断,神经两断端原位缝合,制作大鼠坐骨神经损伤动物模型,然后随机分为2组,实验组于坐骨神经切断处外膜内、外注射纤维蛋白凝胶/血管内皮生长因子复合体;对照组于同处注射血管内皮生长因子165质粒。于用药后4,8,12周行大体观察、神经功能指数检测、电生理检测(测运动神经传导速度)。 结果与结论：两组动物伤口均为一期愈合。实验组用药后1周有6只出现足底溃疡伴肌萎缩;对照组有5只出现足底溃疡。实验组4周时,纤维蛋白凝胶基本被吸收;8周时完全吸收;12周时,神经外形基本正常。对照组4周时,神经轻度充血、水肿;8周时,神经无水肿,与周围组织见少量粘连;12周时,神经周围见瘢痕形成。实验组4,8周的神经功能指数、运动神经传导速度较对照组降低(P < 0.05),12周无显著性差异(P > 0.05)。提示纤维蛋白凝胶可以作为血管内皮生长因子的载体,纤维蛋白凝胶携载血管内皮生长因子给药可以促进损伤神经结构和功能的恢复。 关键词：坐骨神经;损伤;纤维蛋白凝胶;血管内皮生长因子;载体 doi:10.3969/j.issn.1673-8225.2010.29.015     

生物蛋白胶复合骨髓间充质干细胞修复兔多层软组织缺损

背景：符合软组织生理结构的生物蛋白胶适合作为修复软组织缺损的载体材料。 目的：观察生物蛋白胶复合骨髓间充质干细胞修复软组织缺损的可行性。 方法：在新西兰大白兔大腿处造成深达肌肉层,直径大于3 cm的软组织缺损。将24只新西兰大白兔随机分为3组,实验组将同种异体来源的骨髓间充质干细胞复合生物蛋白胶注射到软组织缺损处,对照组将生物蛋白胶注射到软组织缺损处,模型组造模后不注射。 结果与结论：术后14,21 d创面收缩率,实验组>对照组>模型组(P < 0.01);愈合时间,实验组<对照组<模型组(P < 0.01)。结果显示以生物蛋白胶为载体复合骨髓间充质干细胞能快速的修复多层软组织缺损。     

Comparison of fibrin glue, bioresorbable tubing and sutures in peripheral nerve repair

Regeneration of severed rat tibial nerves was functionally and morphologically compared with repair following the use of 3 anastomosis techniques: collagen guide tubes, fibrin glue and conventional microsurgical sutures. In addition, one tibial nerve was crushed in some rats. At ten weekly intervals, functional recovery, assessed by sciatic nerve stimulated evoked contraction of the flexor digitorum muscle, was quicker and more complete following nerve crush than following the anastomosis techniques which were not different from each other. Ten weeks following the surgery, the retrograde transport morphological technique indicated that the anastomosis techniques were not different from each other. The number of labeled tibial motoneurons (tube and suture groups) was significantly less than the crush group, but the glue group was intermediate. Thus, although having less extensive recovery following crush, the quicker and easier techniques of nerve repair, i.e., collagen tubes or fibrin glue, produced comparable anatomical and functional recovery as the more time-consuming, technically demanding microsurgical repair with fine sutures.     

周围神经联合生长因子移植治疗急性脊髓损伤

背景：目前促进神经再生与修复的策略也主要是通过促进神经内在的再生能力和改善再生的微环境两大途径,已有的研究表明联合应用一些治疗手段能更好地促进神经轴突的再生生长。 目的：探讨周围神经联合生长因子移植治疗大鼠脊髓损伤的可行性及效果。 方法：健康成年雌性SD大鼠60只,随机数字表法分为4组：神经移植组、神经移植联合生长因子组、脊髓横断组、椎板切除组。以T9为中心纵行切开大鼠皮肤,显露硬膜囊,水平切断脊髓并切除3mm,神经移植组、神经移植联合生长因子组取双侧第8~10对肋间神经各2 cm,将自体肋间神经修剪成合适长度后交叉移植入脊髓缺损处(近端白质与远端灰质、远端白质与近端灰质),神经移植组用纤维蛋白凝胶固定植入的肋间神经,神经移植联合生长因子组用含有2.1 mg/L 酸性成纤维细胞生长因子的纤维蛋白凝胶固定植入的肋间神经,缝合硬膜。脊髓横断组断端间旷置,椎板切除组仅行椎板切除术。术后90 d进行体感及运动诱发电位检测,术后70 d进行Basso.Beattie.Bresnahan(BBB)后肢运动功能评分。 结果与结论：椎板切除组均引出了体感及运动诱发电位;脊髓横断组未引出体感及运动诱发电位波形;神经移植组3只引出双侧体感诱发电位,4只引出单侧体感诱发电位,4只引出双侧运动诱发电位,3只引出单侧运动诱发电位,神经移植联合生长因子组5只引出双侧体感诱发电位,2只引出单侧体感诱发电位,神经移植联合生长因子组5只引出双侧运动诱发电位,2只引出单侧运动诱发电位。神经移植组、神经移植联合生长因子组大鼠体感及运动诱发电位潜伏期及波幅明显优于脊髓横断组(P < 0.01),自体肋神经移植联合生长因子组优于神经移植组(P < 0.01)。椎板切除组大鼠麻醉清醒后运动恢复正常, 脊髓横断组在3个月的生存期内后肢持续伸展、旋转,神经移植组和神经移植联合生长因子组大鼠后肢功能术后3周开始明显恢复,并在整个观察期内逐渐恢复。神经移植组和神经移植联合生长因子组BBB后肢运动功能评分较脊髓横断组明显提高(P < 0.01),并且神经移植联合生长因子组较神经移植组高(P < 0.01)。提示单纯周围神经移植能部分恢复脊髓功能,联合生长因子则能更好地恢复脊髓功能。     

睫状神经营养因子对面神经损伤修复大鼠面神经核内STAT3磷酸化的影响

目的 探讨重组人睫状神经营养因子（ciliary neurotrophica factor．CNTF）对面神经损伤修复大鼠面神经核运动神经元STAT3活性的影响。方法 成年大鼠面神经切断后行端端吻合．局部给予CNTF．以生理盐水为对照。术后7d．运用抗磷酸化STAT3抗体做免疫印迹（immuobloting，IB）以检测面神经核抽提物STAT3的磷酸化变化。结果 局部给予CNTF组大鼠面神经核内p-STAT含量较对照组高（P〈0．05）。结论 局部给予重组CNTF可增强面神经损伤修复大鼠面神经核内STAT3的磷酸化。     

Platelet-rich plasma gel in combination with Schwann cells for repair of sciatic nerve injury

Bone marrow mesenchymal stem cells were isolated from New Zealand white rabbits, culture-expanded and differentiated into Schwann cell-like cells. Autologous platelet-rich plasma and Schwann cell-like cells were mixed in suspension at a density of 1 × 10 6 cells/mL, prior to introduction into a poly (lactic-co-glycolic acid) conduit. Fabricated tissue-engineered nerves were implanted into rabbits to bridge 10 mm sciatic nerve defects (platelet-rich plasma group). Controls were established using fibrin as the seeding matrix for Schwann cell-like cells at identical density to construct tissue-engineered nerves (fibrin group). Twelve weeks after implantation, toluidine blue staining and scanning electron microscopy were used to demonstrate an increase in the number of regenerating nerve fibers and thickness of the myelin sheath in the platelet-rich plasma group compared with the fibrin group. Fluoro-gold retrograde labeling revealed that the number of Fluo-ro-gold-positive neurons in the dorsal root ganglion and the spinal cord anterior horn was greater in the platelet-rich plasma group than in the fibrin group. Electrophysiological examination confirmed that compound muscle action potential and nerve conduction velocity were superior in the plate-let-rich plasma group compared with the fibrin group. These results indicate that autologous plate-let-rich plasma gel can effectively serve as a seeding matrix for Schwann cell-like cells to construct tissue-engineered nerves to promote peripheral nerve regeneration.     

Endogenous automatic nerve discharge promotes nerve repair: an optimized animal model

Exogenous electrical nerve stimulation has been reported to promote nerve regeneration. Our previous study has suggested that endogenous automatic nerve discharge of the phrenic nerve and intercostal nerve has a positive effect on nerve regeneration at 1 month postoperatively, but a negative effect at 2 months postoperatively, which may be caused by scar compression. In this study, we designed four different rat models to avoid the negative effect from scar compression. The control group received musculocutaneous nerve cut and repair. The other three groups were subjected to side-to-side transfer of either the phrenic(phrenic nerve group), intercostal(intercostal nerve group) or thoracodorsal nerves(thoracic dorsal nerve group), with sural nerve autograft distal to the anastomosis site. Musculocutaneous nerve regeneration was assessed by electrophysiology of the musculocutaneous nerve, muscle tension, muscle wet weight, maximum cross-sectional area of biceps, and myelinated fiber numbers of the proximal and distal ends of the anastomosis site of the musculocutaneous nerve and the middle of the nerve graft. At 1 month postoperatively, compound muscle action potential amplitude of the biceps in the phrenic nerve group and the intercostal nerve group was statistically higher than that in the control group. The myelinated nerve fiber numbers in the distal end of the musculocutaneous nerve and nerve graft anastomosis in the phrenic nerve and the intercostal nerve groups were statistically higher than those in the control and thoracic dorsal nerve groups. The neural degeneration rate in the middle of the nerve graft in the thoracic dorsal nerve group was statistically higher than that in the phrenic nerve and the intercostal nerve groups. At 2 and 3 months postoperatively, no significant difference was detected between the groups in all the assessments. These findings confirm that the phrenic nerve and intercostal nerve have a positive effect on nerve regeneration at the early stage of recovery. This study established an optimized animal model in which suturing the nerve graft to the distal site of the musculocutaneous nerve anastomosis prevented the inhibition of recovery from scar compression.     

Sciatic nerve repair using adhesive bonding and a modified conduit

When repairing nerves with adhesives, most researchers place glue directly on the nerve stumps, but this method does not fix the nerve ends well and allows glue to easily invade the nerve ends. In this study, we established a rat model of completely transected sciatic nerve injury and re- paired it using a modified 1 cm-length conduit with inner diameter of 1.5 mm. Each end of the cylindrical conduit contains a short linear channel, while the enclosed central tube protects the nerve ends well Nerves were repaired with 2-octyl-cyanoacrylate and suture, which complement the function of the modified conduit. The results demonstrated that for the same conduit, the av- erage operation time using the adhesive method was much shorter than with the suture method. No significant differences were found between the two groups in sciatic function index, motor evoked potential latency, motor evoked potential amplitude, muscular recovery rate, number of medullated nerve fibers, axon diameter, or medullary sheath thickness. Thus, the adhesive method for repairing nerves using a modified conduit is feasible and effective, and reduces the operation time while providing an equivalent repair effect.     

Effects of different nerve autografts on greater auricular nerve deficit in rabbits

BACKGROUND: Autograft is commonly used to repair nerve deficit. Usually, the choice of donor nerves is based on their similarities in form and structures to the injured nerves. For the reason, the cutaneous antebrachii lateralis nerve is currently considered the most suited for digital nerve repair. OBJECTIVE: To compare early nerve regeneration after transplantation of three different autografts: the greater auricular nerve (GAN), the saphenous nerve (SN) and the lateral femoral cutaneous nerve (LFCN). DESIGN: Observational contrast study. SETTING: Department of Plastic Surgery and Burns, Tangdu Hospital, Fourth Military Medical University of Chinese PLA. MATERIALS: A total of 42 New Zealand rabbits, of both genders, 12–14 months old and weighing 2.0–2.5 kg, were used in this study. In addition, Moller-spetra 900 operating microscope (Germany), Olympus BX 51 microscope, DP 70 image collecting System (Japan), BL-420E+ Biologic function testing System (China), JEM-100 electron microscope (Japan), Reichet-JunG820 Cryostat (Swiss), and Libror-AEG-120 precision analytical Balance (Japan) were also used in this study. METHODS: The experiment was carried out in the Department of Plastic Surgery and Burns, Tangdu Hospital, Fourth Military Medical University of Chinese PLA from April to November 2005. After anaesthesia, the GAN were dissected bilaterally and a 1.2 cm deficit was made in each nerve. The animals were randomly divided into three groups, including GAN group, SN group and LFCN group with 14 in each group. ① Nerve pinch test: At 1, 2, and 4 weeks after operation, three animals in each group were tested. The nerve grafts, along with the proximal and distal GAN segments were exposed and pinched with microsurgical forceps in distal-proximal orientations. The distance between the proximal anastomosis site and the most distal point, where the pinch evoked an ear contraction response, was measured as distance of nerve regeneration. ② Computer image analysis: At 4 and 12 weeks, 2 μm sections were prepared, each stained with either HE or methylene blue to assess axon number and density, cross-section area, and myelin sheath thickness. ③ Electrophysidogical tests: At 12 weeks, the bilateral GAN along with the nerve grafts of 4 animals in each group were exposed. Points A, B and C were marked on each specimen: point A: at the proximal GAN segment, 7 cm from the proximal anastomosis; point B: 0.5 cm from the proximal anastomosis; point C: at the distal GAN segment, 0.5 cm from the distal anastomosis. The whole nerve including nerve graft and proximal and distal GAN segments, as a block, was harvested and immersed in Ren's solution for several minutes until its excitability was stabilized. The specimen was then placed on the electrodes of the shield box to examine the action potential and conduction velocity on segment AB and AC with BL-420E+biologic function testing system. AC/AB would be the recovery rate of action potential on segment AC. ④ Horseradish peroxidase (HRP) fascicle: At 12 weeks, at the site on the distal segment of GAN 1.0 cm from the distal anastomosis of nerve graft, the GAN was crushed by a pair of haemostatic forceps and HRP water solution was injected into the nerve. Two rabbits in GAN group, SN group and LFCN group, after having survived for 24 hours, 36 hours and 48 hours were selected. The C2 ganglion was exposed and the distance from C2 ganglion to HRP injection site was taken as the axoplasmic transport distance, from which the axoplasmic transport velocity and the mean density of the labeled C2 ganglion cells were calculated. MAIN OUTCOME MEASURES: ① The greatest distance of nerve regeneration; ② the axon number and density, cross-section area, and myelin sheath thickness; ③ the action potential and conduction velocity; ④ the axoplasmic transport velocity and the mean density of the labeled C2 ganglion cells. RESULTS: All 42 experimental rabbits were involved in the final analysis. ① The greatest distance of nerve regeneration: At 4 weeks after operation, the greatest distance of nerve regeneration was longer in the SN group than that in the GAN group and the LFCN group [(45.17±2.48), (41.83±2.32), (34.83±2.64) mm, P < 0.05], while the greatest distance of nerve regeneration was longer in the GAN group than that in the LFCN group (P < 0.05). ② The axon number and density, cross-section area, and myelin sheath thickness: The number of nerve fascicle was the greatest in the GAN group, and the cross-section area was the most; however, ratio between nerve fascicle and cross-section area, and the axon density were lower than those in other two groups (P < 0.05–0.01). In contrast, the axon density was the greatest in the SN group. At 4 weeks after operation, axon density was the most in the SN group, and then the GAN group and the LFCN group. There were significant differences among the three groups (P < 0.05–0.01). At 12 weeks after operation, density of myelinated fiber and axon section area were higher in the SN group than those in other two groups (P < 0.05–0.01). ③ The action potential and conduction velocity: At 12 weeks after operation, the maximal action potential, the recovery rate of action potential and the nerve conduction velocity were the highest in the SN group. HRP-labeled neurons early occurred in C2 ganglion, and the action potential and the recovery rate of action potential were increased (P > 0.05). At 12 weeks after operation, even though the maximal action potential, the recovery rate of action potential and the nerve conduction velocity on segment AB remained similar in different groups, on segment AC, the action potential, the recovery rate of action potential and nerve conduction velocity were greater in the SN group than those in other groups. ④ The axoplasmic transport velocity and the mean density of the labeled C2 ganglion cells: After HRP injection in the SN group, the positive labeled cells in C2 ganglion firstly appeared at 24 hours, and in other two groups, they did not appeared until 36 hours. The density of labeled cells was the greatest in the SN group and the lowest in the LFCN group. The axoplasmic transport velocity in the SN group was also significantly faster than in the GAN group and the LFCN group (P < 0.05–0.01). Otherwise, the axoplasmic transport velocity was faster in the SN group than that in the GAN group and the LFCN group. CONCLUSION: The donor nerve with greater axon number and density can achieve much better effects during early regeneration.