Evaluation of specialized laparoscopic suturing and tying devices.

BACKGROUND: Laparoscopic suturing and tying constitute advanced minimally invasive surgery skills. Developing proficiency in the standard methods with needle drivers is often an arduous process. Recent advances in laparoscopic instrumentations has allowed for easier methods of suturing and tying. This study investigated the hypothesis that the use of a specialized suturing device and a specialized tying device allows inexperienced medical students to suture and tie laparoscopically. METHODS: Preclinical medical students who had not received any training in open or laparoscopic surgery were included in this investigation. Each student was given a 5-minute demonstration of a specialized suturing device and a specialized tying device. The medical students were not allowed to deploy either device before actual use. After the demonstration, each student was given the device to use in a porcine model. Times were recorded and a subjective grade was given for each student. RESULTS: Twenty medical students were involved in this study. All medical students were able to complete the task of suturing and tying. The average time to suture was 104.6 seconds and the average time to tying was 31.2 seconds. The average subjective performance grade was 90 (out of 100). CONCLUSION: Specialized devices are easy to learn and use for laparoscopic suturing and tying with minimal instruction even for inexperienced medical students. Even surgeons who are not well versed in laparoscopic surgery should be able to suture and tie with certain laparoscopic instruments.     

大鼠肾移植模型技术的改进

目的 为开展器官移植的实验研究，建立了大鼠异体肾移植模型。方法使用Wistar大鼠分别作为供者和受者，采用原位低温灌洗，肾动脉带一小段主动脉，肾静脉带一小段下腔静脉、输尿管末端带一直径约为0．5cm的膀胱瓣的供者手术方式；受者主动脉与供者主动脉、受者下腔静脉与供者下腔静脉进行端侧吻合，在受者膀胱上剪去一膀胱瓣与供者相同大小的圆瓣，然后进行一层膀胱吻合。结果 第一阶段为实验探索阶段，经过半年近150次的实验摸索，克服了移植物灌洗、血管吻合、膀胱吻合等技术难关，终于建立了比较稳定的大鼠同种异体肾移植模型。第二阶段为模型成熟阶段，冷热缺血时间、血管吻合的速度以及手术时间都比第一阶段有所缩短。手术成功率为85％左右，动物死亡的原因主要为血管吻合口出血、灌洗不良、休克、血栓形成以及膀胱漏尿致弥漫性腹膜炎等。结论 此模型容易掌握，可以在条件比较简单的实验室开展，除常规显微外科器械外不需要特殊的器械或设备。     

兔心肌梗塞模型制备方法的改进及其在MRI中的应用

目的　对兔心肌缺血的模型制备方法进行改进 ,并探讨其在 MRI诊断研究中的价值。方法　分别采用高位结扎左冠状动脉前降支 (L AD)和同时低位结扎 L AD及左冠状动脉旋支 (L Cx)建立兔心肌梗塞模型 ,并在术后行 MRI检查 ,对取材后心肌标本行氯化三苯四氮唑 (TTC)及病理检查。结果　 1L AD组 2 0 % (5 / 2 5 )发生心室颤动导致死亡 ,L AD +L Cx组无一例发生室颤死亡。 2 L AD组 EKG改变明显者占 5 6 % (14 / 2 5 ) ,其中 2 1.4 3% (3/14 )在即刻就有 EKG明显改变 ,并在 30分钟后恢复正常 ;EKG改变不明显者占 4 4 % (11/ 2 5 ) ;L AD +L Cx组 10 0 %有 EKG明显改变 ,且 30分钟后亦无明显恢复。 3L AD组心肌梗塞范围较小 ,并均限于左室前壁 ,室间隔前部损害 ;而 L AD+L Cx组心肌梗塞范围较大 ,且累及左室前壁及侧壁 ,无一例有室间隔前部损害。4 L AD组中有 30 % (6 / 2 0 )不能显示小灶缺血局部心肌运动降低 ,16 .6 7% (3/ 18)无法分辨早期小梗塞灶的 MRI信号变化 ;而 L AD+L Cx组均能显示缺血局部心肌运动降低及梗塞灶早期的 MRI信号变化。结论　低位结扎兔心 L AD+L Cx,手术死亡率低 ,EKG改变明显 ,梗塞面积较大 ,是 MRI研究中一种较理想的心肌缺血动物模型制备方法。     

米诺环素对压力作用下体外培养视网膜神经细胞凋亡的抑制

目的 观察米诺环素对压力系统作用下大鼠视网膜神经细胞(RNs)的活性及凋亡的影响，探讨其对受损RNs保护的可能机制。 方法 制备大鼠RNs体外加压培养模型，通过细胞形态学观察、四唑盐（MTT）比色法测定细胞活力、吖啶橙/溴化乙锭（AO/EB）染色法检测细胞凋亡率等方法观察不同浓度的米诺环素对上述损伤细胞的保护作用，并用免疫细胞化学法观察iNOS和caspase 3表达的改变。 结果 加压培养后RNs与对照组相比形态改变较明显，细胞活力降低，5393%的细胞发生凋亡。20000 μmol/L的米诺环素治疗组则细胞形态改善，活力显著增高，1729%的细胞发生凋亡；免疫细胞化学法显示细胞内iNOS和caspase-3表达较加压损伤组减少。 结论 一定剂量的米诺环素在体外可有效抑制压力引起的大鼠RNs损伤及凋亡；抑制iNOS和caspase-3的表达可能是其潜在作用机制。     

新胆碱酯酶抑制剂对实验性重症肌无力的治疗作用

本文应用实验性重症肌无力模型研究了7种新的胆碱酯酶抑制剂对实验性重症肌无力的治疗作用,其中包括6种二甲氨基甲酸烷氧(烷硫)基苯酯及1种中草药提取物,大多数化合物对乙酰胆碱酯酶有较强的抑制作用,并见到有不同程度的治疗效果。二甲氨基甲酸-3-叔丁基-4〔2-(1-哌啶基)乙氧基〕苯酯不仅明显改善肌无力症状,而且毒性小、副作用较新斯的明轻,值得进一步研究。     

实验性腹主动脉瘤瘤体外径与iNOS相关性分析及分期研究

Objective To construct new model of experimental abdominal aortic aneurysm (AAA) and detect the AAA outer diameter and the change of induce nitric oxide synthase(iNOS) in the abdominal aor-tic aneurysm in different period,and analysis the correlation between experimental AAA and iNOS.Methods During the operation of the experiment group,the vascular prosthesis of PTFE was implanted to the rabbit abdominal aorta to form an aneurysm,while sham operation was done in the control group.The tissue of ab-dominal aortic aneurysm was harvested in 1 d,7d,14d,and 28d after operation,respectively.The tissue bo-mogenate concentration of iNOS in the abdominal aortic aneurysm were detected by enzyme linked immu-nosorbent assay (ELISA).Results In experimental group,mean concentration of the tissue bomogenate concentration of iNOS in the abdominal aortic aneurysm in 1 d,7 d,14 d,28 d were (22.129 ±2.518)μ/mL,(27.337±5.321) μ/mL,(36.047±4.584)μ/mL,(44.756±1.799)μ/mL,respectively;In control group,that was (12.499±1.807)μ/mL.The concentration of iNOS in experimental group was significantly higher than that of control group (P < 0.01).The difference during the experimental group all had statisti-cal significance (P < 0.05).Conclusion It is possible that iNOS has some biological function during the formation and progression of the abdominal aortic aneurysm.     

兔坐骨神经挤压伤的MRI与SEP对比研究

目的:探讨磁共振成像和体感诱发电位以及两者结合在坐骨神经急性挤压伤中的诊断价值。方法:24只兔按钳夹力的不同随机分为A、B两组,左后肢为损伤侧,右后肢为对照侧,建立坐骨神经急性挤压伤模型,于伤后1、2、4、8周行MR扫描,同时行双侧体感诱发电位检查。结果:损伤侧24条神经,有23条MR显示异常,诊断正确率95.8%,假阴性率4.17%(1/24);24条损伤侧坐骨神经,有22条SEP显示异常,诊断正确率91.6%,假阴性率8.3%(2/24)。MRI与SEP对神经损伤的正确诊断率无统计学差异(P>0.05)。MRI与SEP结合起来,24条损伤神经均显示异常,诊断正确率100%。结论:MR与SEP检查可无创、准确地判断神经损伤,两者结合可明显提高神经损伤的正确诊断率,重复性好,可作为神经损伤的较好诊断手段。     

三氧化二砷-碘油化疗栓塞对兔肝移植瘤转移及与血管形成关系的研究

目的观察三氧化二砷（ As2O3）-碘油经肝动脉化疗栓塞对兔VX2肝移植瘤生长及转移的影响及与血管形成的关系。方法 48只家兔肝内肿瘤种植后2周，完全随机法分为4组，经肝动脉插管分别给予不同处理，实验设生理盐水灌注组、单纯碘油栓塞组、阿霉素．碘油栓塞组及 As2O3-碘油栓塞组。治疗后1周，免疫组织化学测定肿瘤区的微血管密度（MVD），治疗后3周，测量计算肝移植瘤的体积、坏死面积，观察肝内、双肺及其他器官肿瘤转移的发生率。结果 治疗后1周，各组MVD分别为（21．8±5．3）、（23．4±3．9）、（22．4±4．50）、（14．3±3．4）条／400倍视野（F=11．246，P=0．000）， As2O3-碘油栓塞治疗组与其他组相比差异有统计学意义；肿瘤植入后5周，各处理组肿瘤体积分别为（35．5±7．1）、（21．2±8．3）、（20．7±9．1）、（11．8±3．7）cm^3（F=21．203，P=0．000）。单纯碘油栓塞组、阿霉素一碘油栓塞组及 As2O3-碘油栓塞组与生理盐水灌注组相比差异有统计学意义（q值分别为6．723、6．940、11．119，P〈0．05）， As2O3-碘油栓塞组与单纯碘油栓塞及阿霉素-碘油栓塞组相比差异有统计学意义（g值分别为4．398、4．178，P值均〈0．05）；各组肿瘤坏死面积间差异无统计学意义（F=1．284，P=0．292）； As2O3-碘油栓塞治疗组双肺转移结节数目少于其他组（H=14．983，P=0．002），结节直径小于其他组（F=4．580，P=0．007），差异有统计学意义。腹腔转移淋巴结记分显示 As2O3-碘油栓塞治疗组腹腔淋巴结转移少于其他组（H=9．148，P=0．027）。双肺转移结节的数目、直径及腹腔转移淋巴结与肿瘤的微血管密度呈正相关（P〈0．05）。结论 As2O3-碘油联合经肝动脉栓塞治疗，抑制兔肝移植瘤的生长，抑制肿瘤的肺及腹腔淋巴结转移，其抑制转移的机制可能与抑制肿瘤血管形成有关。     

Assessing the Stiffness of Spinal Fusion in Animal Models

The clinical goal of spinal fusion is to reduce motion and the associated pain. Therefore, measuring motion under loading is critical. The purpose of this study was to validate four-point bending as a means to mechanically evaluate simulated fusions in dog and rabbit spines. We hypothesized that this method would be more sensitive than manual palpation and would be able to distinguish unilateral vs bilateral fusion. Spines from four mixed breed dogs and four New Zealand white rabbits were used to simulate posterolateral fusion with polymethyl methacrylate as the fusion mass. We performed manual palpation and nondestructive mechanical testing in four-point bending in four planes of motion: flexion, extension, and right and left bending. This testing protocol was used for each specimen in three fusion modes: intact, unilateral, and bilateral fusion. Under manual palpation, all intact spines were rated as not fused, and all unilateral and bilateral simulated fusions were rated as fused. In four-point bending, dog spines were significantly stiffer after unilateral fusion compared with intact in all directions. Additionally, rabbit spines were stiffer in flexion and left bending after unilateral fusion. All specimens exhibited significant differences between intact and bilateral fusion except the rabbit in extension. For unilateral vs bilateral fusion, significant differences were present for right bending in the dog model and for flexion in the rabbit. Unilateral fusion can provide enough stability to constitute a fused grade by manual palpation but may not provide structural stiffness comparable to bilateral fusion.     

慢性应激对大鼠血管平滑肌细胞的效应及与焦虑行为的关系

目的探讨慢性精神应激对血管平滑肌细胞的影响及与焦虑行为的关系。方法将38只SD大鼠按照随机数字表随机分为精神应激组(30只)和对照组(8只)。对应激组采用限制应激和饮水冲突应激,持续2个月;分别于应激前、应激后1,2个月用空场实验和高架十字迷宫实验观察大鼠焦虑水平,计算出中央格爬行次数、外周格爬行次数、开放臂进入次数及停留时间、闭合臂进入次数及停留时间。以免疫组化方法测定主动脉血管局部增殖细胞核抗原(PCNA)表达,并用苏木素-伊红染色法观察主动脉结构变化。结果(1)与对照组比较,应激1个月后,应激组大鼠在开放臂的次数和时间、闭合臂的次数少(P<0·05),闭合臂的时间多(均P<0·01);应激2个月后,应激组大鼠在外周格爬行的个数和闭合臂时间多(P<0·01),开放臂时间少(P<0·01)。(2)应激组大鼠主动脉失去原有的正常结构,中层血管平滑肌细胞排列紊乱,数目增多。(3)应激组大鼠血管壁PCNA表达的阳性细胞数为(16485±10694)个/MM2,对照组大鼠为(4012±2256)个/MM2,T=4·359,P<0·01。(4)中度焦虑组大鼠PCNA表达与大鼠焦虑呈正相关(PEARSON相关系数为0·718,P=0·004)。结论大鼠中度焦虑时,其血管平滑肌细胞增殖率与焦虑情绪呈正相关。