Stem cell dynamics in an experimental model of stroke

We investigated the migration of endogenous neural stem cells (NSCs) toward an infarct lesion in a photo-thrombotic stroke model. The lesions produced by using rose bengal dye (20 mg/kg) with cold light in the motor cortex of Sprague-Dawley rats were also evaluated with sequential magnetic resonance imaging (MRI) from 30 minutes through 8 weeks. Migration of NSCs was identified by immunohistochemistry for nestin monoclonal antibody in the lesion cortex, subventricular zone (SVZ), and corpus callosum (CC). The contrast to noncontrast ratio (CNR) on MRI was greatest at 12 hours in DWI and decreased over time. By contrast, T1-weighted and T2-weighted images showed a constant CNR from the beginning through 8 weeks. MRI of the lesional cortex correlated with histopathologic findings, which could be divided into three stages: acute (edema and necrosis) within 24 hours, subacute (acute and chronic inflammatory cell infiltration) at 2 to 7 days, and chronic (gliofibrosis) at 2 to 4 weeks. The volume of the infarct was significantly reduced by reparative gliofibrosis. The number of nestin(+) NSCs in the contralateral SVZ was similar to that of the ipsilateral SVZ in each group. However, the number of nestin(+) NSCs in the ipsilateral cortex and CC increased at 12 hours to 3 days compared with the contralateral side (p<0.01) and was reduced significantly by 7 days (p<0.01). Active emigration of internal NSCs from the SVZ toward the infarct lesion may also contribute to decreased volume of the infarct lesion, but the self-repair mechanism by endogenous NSCs is insufficient to treat stroke causing extensive neuronal death. Further studies should be focused on amplification technologies of NSCs to enhance the collection of endogenous or transplanted NSCs for the treatment of stroke.     

新生大鼠脑缺氧缺血损伤模型的建立

目的按Rice方法建立新生大鼠脑缺氧缺血损伤(HIBD)模型.方法 7 d龄SD新生大鼠62只,随机分为正常对照组(n=14)、假手术组(n=14)及HIBD模型组(n=34).HIBD模型组大鼠行左侧颈总动脉永久性结扎,2 h后置于37℃恒温水浴的1L有机玻璃缺氧舱中,输入氧浓度为8%±0.1%的氮氧混合气体持续缺氧2 h,观察缺氧缺血后24 h内神经行为变化及24、48、72 h脑组织病理改变,并用干湿法测定24 h脑含水量. 结果 HIBD模型组大鼠神经行为异常发生率为94.12%,正常对照组和假手术组未发生神经行为异常.HIBD模型组左侧脑组织出现明显的病理改变,HE染色可见神经元损伤和神经胶质细胞增生;正常对照组和假手术组脑组织未见异常.HIBD模型组左脑含水量较右脑、正常对照组和假手术组显著增加(P<0.001).结论应用Rice方法建立的新生大鼠HIBD模型稳定性良好,其病理变化有一定的规律性,该模型的建立对于研究新生儿HIBD具有重要意义.     

Physiological study of anal sphincteric resection in an experimental porcine model

This study was conducted to compare and evaluate the extent of anal sphincteric resection and the degree of anal dysfunction in sphincter saving operations for lower rectal cancer using experimental porcine models. Each 10 Clawn miniature pigs underwent transanal intersphincteric resection (ISR), ISR with partial (one-quarter) external sphincteric resection (ESR-25%), and ISR with partial (one-half) external sphincteric resection (ESR-50%). An anorectal physiological study was performed before, one month, and three months after surgery in these three groups. The anal maximum resting pressure (AMRP) decreased from 45.1 cmH(2)O in the control group to 14.8, 14.3 and 11.1 cmH(2)O one month after surgery, and to 15.2, 8.8 and 5.2 cmH(2)O three months after surgery, in the ISR, ESR-25% and ESR-50% groups, respectively. The anal maximum squeezing pressure (AMSP) decreased from 81.7 cmH(2)O in the control group to 42.1, 40.1 and 41.1 cmH(2)O one month after surgery in the ISR, ESR-25% and ESR-50% groups, respectively. Three months after surgery, the MSP increased to 78.1 and 68.1 cmH(2)O in the ISR and ESR-25% groups, respectively, but the ESR-50% group showed a significantly lower MSP of 39.2 cmH(2)O compared with other two groups. The ratio of the potential difference on electromyographic (EMG) was 0.19 in the ESR-50% group, and this value was significantly lower than 0.8 in the ISR and ESR-25% groups, one month after surgery. Three months after surgery, the potential ratio of EMG was increased almost to the preoperative level both in the ISR and ESR-25% groups, but the ratio of the potential difference in the ESR-50% group with redness, sore and soiling around anus was 0.19 and significantly lower compared with other groups. The results of this study indicate that porcine models with additional resection of less than one quarter of the external anal sphincter have little anal dysfunction. A human clinical trial is needed to determine the ESR for very low rectal cancer.     

蜂胶对致癌物诱导金仓鼠舌黏膜反应的影响

目的：研究9，10-二甲基-1，2-苯并蒽（9，10-dimethyl-1，2-benzanthracene，DMBA）以及蜂胶乙醇提取物（ethanol extract of propolis，EPE）对金仓鼠舌黏膜组织反应的影响。方法：60只金仓鼠按实验周期被随机分为两大组，每组再被分为EPE组、蜂胶水提取物（aqueous propolis extract，APE）组和DMBA组（n=20）。测定实验鼠舌黏膜的临床和组织学改变，包括面积、容积的临床改变，鳞状上皮组织的结构和细胞学变化，并测量鳞状细胞癌组织学上的改变区域。结果：各组在第13周和第20周所测定的实验结果不存在显著差异。在第13周，EPE组出现1例单-鳞状细胞癌；在第20周，EPE组的鳞状细胞癌的发生率最高，但与其他组比较差异无统计学意义。结论：蜂胶乙醇提取物对舌黏膜组织的影响以及其致癌机制还有待研究。     

自体肺体外循环实验动物模型的建立

目的：试建立自体肺体外循环实验动物模型。方法：杂种犬16只,静脉麻醉后气管插管行人工呼吸。开胸,右心房、肺动脉插管,连接贮血器、泵建立右心体外循环系统;左心房、升主动脉插管,连接贮血器、变温器和泵建立左心体外循环系统。结果：15只犬顺利建立自体肺体外循环,1只失败。结论：模型建立成功的要点是熟练的插管技术,左右心系统转流平衡,适宜的体温。     

Three-dimensional echo-guided suture of atrial septal defect with Maniceps in an experimental model

Toward the establishment of suture closure procedures for atrial septal defect or patent foramen ovale under guidance of three-dimensional (3D) echocardiography but without use of cardiopulmonary bypass (off-pump surgery), an experimental study was conducted using a laparoscopic suture instrument, Maniceps. First, the panel setting of the 3D echo system which was optimal for precisely visualizing the surgical instruments on the image display with the least time delay was determined. The optimal setting was: 1) harmonic imaging, 2) no smoothing, 3) low scanning line density, and 4) a scanning range around 55 degrees. Using an ex vivo model of atrial septal defect, 3D echo-guided surgical procedures were attempted in three steps. First, grasping of the edge of the defect with a forceps was attempted. It was feasible in every direction. Reverberation artifact occasionally disturbed imaging of the defect edge. Second, transfixion suture of the facing edges was attempted. Guided by 3D echo, serial sutures were feasible, but interlocking of the thread was a pitfall. Third, continuous suture of the defect was attempted under 3D echo guidance. Following the initial suture bite on one side, continuous suture could be performed under echo guidance. Deformity of the Maniceps needle after repeated sutures was a limitation. In conclusion, suture closure of the defect under 3D echo guidance using the Maniceps system is feasible in an ex vivo ASD model as visualization is optimized by panel setting for guiding surgical procedures.     

再造阴茎感觉功能重建动物模型的建立

目的:建立再造阴茎感觉功能重建的动物模型,为临床上改善阴茎再造术后感觉功能探索新术式.方法:以成年新西兰雄兔为实验对象,采用腹壁浅血管筋膜蒂岛状皮瓣行阴茎再造术,切取一段隐神经游离移植,与阴茎背神经端端吻合植入皮瓣后阴茎成形.术后不同时间对再造阴茎进行组织形态学观察和感觉神经肽(calcitonin gene related peptide,CGRP)免疫组化标记.结果:再造阴茎术后1个月时少量CGRP阳性神经纤维仅见于真皮深层,术后3个月数量明显增多,并开始出现在真皮浅层以及真皮乳头内,术后6个月真皮与表皮交界层以及皮肤附属器周围也可见CGRP阳性纤维.结论:隐神经游离移植与阴茎背神经吻接植入再造阴茎皮瓣内可以获得良好的神经再生,这一动物模型可为临床应用该术式重建再造阴茎感觉功能提供实验依据.     

心房颤动心房交感神经过度支配机制的实验研究

目的 研究心房颤动(房颤)心房交感神经过度支配的机制.方法 14只犬被随机分为假手术组和起搏组,起搏组犬右心房400次/分起搏6周建立房颤犬模型.起搏6周后,免疫组织化学法检测两组犬左右心房前壁神经萌出和交感神经分布;分别应用实时定量RT-PCR法和蛋白印迹法检测左右心房前壁β-神经生长因子(β-NGF)基因和蛋白表达.结果 心房快速起搏引起心房显著神经萌出和交感神经不均一性过度支配,右心房前壁神经萌出和交感神经密度大于左心房前壁.起搏组犬左右心房前壁心房肌β-NGF基因和蛋白表达显著增加,且右心房前壁心房肌β-NGF含量高于左心房前壁.两组犬心房肌β-NGF蛋白含量与局部交感神经密度显著正相关.结论 心房肌β-NGF过度表达可能是房颤心房不均一性交感神经过度支配的主要机制.     

大鼠肝硬化结节多步癌变模型MR扩散成像实验研究

目的 探讨磁共振扩散成像(diffusion-weighted MR imaging,DWI)对大鼠肝硬化结节多步癌变模型肝内再生结节(regenerative nodule,RN)、不典型增生结节(dysplastic nodules,DN)及肝细胞癌(hepatocellularcarcinoma,HCC)的诊断价值.方法 70只SD大鼠,利用二乙基亚硝胺(diethyjnitr-osamine,DEN)灌胃法建立大鼠肝硬化结节多步癌变模型.MR平扫检出肝内结节,全肝DWI成像,获得肝硬化肝脏及肝内结节性病变的表面扩散系数(apparent diffusion coefficient,ADC).扫描结束后,处死动物,将肝脏大体切片上与磁共振扫描一一对应良好的结节进行病理学分析.对RN、DN、高分化HCC,中分化HCC及低分化HCC的ADC值进行均数闻多重比较.结果 DWI显示并由病理证实的结节共56个,包括8个RN,16个DN,7个高分化HCC,11个中分化HCC和14个低分化HCC.肝硬化肝脏、RN及DN之间的ADC值差异无统计学意义(P>0.05).尽管高分化HCC的ADG值较DN稍小,但是二者之间差异无统计学意义(P>0.05).中分化HCC和低分化HCC的ADC值明显大干其他结节性病变(P<0.05),但中分化HCC和低分化HCC之间差异无统计学意义(P>0.05).结论 MR扩散成像可对肝内结节性病变的诊断提供辅助信息,ADC值有助于鉴别肝硬化肝脏内良、恶性结节.然而,由于高分化HCC和DN的ADC值存在较多重叠,仅仅依靠ADC值尚难以将二者准确区分.     

蜂胶抗动脉粥样硬化的生物学机制

蜂胶是蜂产品中一类非常重要的的天然的活性物质,作为中草药在多方面应用已有几千年的历史,随着国内外学者对蜂胶研究的深入,蜂胶抗动脉粥样硬化的机制也不断被发现。从提取的蜂胶混合物到单一成分的研究,除传统的降脂作用外,还有保护血管内皮、稳定粥样斑块、调节巨噬细胞和信号转导系统等功效,文章从细胞分子水平综述蜂胶抗动脉粥样硬化的作用机制。     

蜂胶的HPLC指纹图谱研究

目的:应用反相高效液相色谱法建立蜂胶药材指纹图谱,对蜂胶进行质量控制。方法:采用Zorbax Extend-C18(250mm×4.6mm,5μm)为分析色谱柱,以甲醇-0.3%醋酸水溶液为流动相测定了18批不同来源蜂胶的HPLC指纹图谱,进行了相似度评价。结果:该方法可使蜂胶中各成分得到较好的分离,根据检测结果确定了15个共有指纹峰,并指认了其中的14个成分。结论:该指纹图谱检测方法简便、重复性好,可用于蜂胶原料的质量控制。     

实验性鸡脂肪肝出血综合征模型的建立与评价

目的 建立一种造模时间较短、成本较低,成功率更高的鸡脂肪肝出血综合征动物模型。方法320只14日龄青脚麻鸡随机分为对照组、高脂模型组、雌激素模型组和高脂结合雌激素模型组,每组设4个重复,每个重复20只,共处理28 d。期间每天观察记录鸡的临床状况,并于实验14、28 d测定血清生化指标、肝脏相关参数以及腹腔脂肪重、肝脏病理形态学变化。结果对照组在28 d内未发生脂肪肝出血综合征,而高脂结合雌激素模型组在实验14 d发生了脂肪肝出血综合征。临床观察见10 d后部分鸡开始出现张口呼吸、嗜睡、腹部大而下垂等临床表现。14 d 及28 d后,剖检见腹腔脂肪过度沉积,肝脏明显肿大、黄染、质脆、边缘钝厚、表面可见散在点状或斑状出血;14 d后,显微镜下可见肝细胞轻度变性,胞质内出现较小的脂肪空泡。28 d后,可观察到大量肝细胞体积极度肿大,胞质内充满较大的脂肪空泡,肝脏结构紊乱等病理学变化;28 d后FLHS发生率高于14 d。血清甘油三酯浓度、总胆固醇浓度、肝脏相对重、腹脂相对重、肝脂率、肝出血分数与对照组相比,差异皆有显著性(P<0.05或P<0.01)。雌激素模型组和高脂模型组的临床症状、剖检特征、病理组织学变化及血液生化指标的变化趋势与高脂结合雌激素模型组相似,但程度稍轻、发生时间较晚。结论通过28 d 的高脂日粮与雌激素复合诱导,可成功建立鸡脂肪肝出血综合征模型。     

半导体激光诱导大鼠脉络膜新生血管模型的实验研究

目的：评价532nm半导体激光诱导棕色挪威(brown norway,BN)大鼠脉络膜新生血管（choroidal neovasularization,CNV）模型的可行性。方法：使用半导体激光（功率150mW,光斑直径75μm,曝光时间0.1s）对10只BN大鼠建立CNV模型。分别于光凝后7、14、21和28?d随机选取5只行眼底荧光素血管造影术（fundus fluorescein angiogrphy,FFA）和光学相干断层成像术（optical coherence tomography,OCT）检查,比较FFA早期（<2min）和晚期（>10min）荧光渗漏斑数/平均渗漏面积（mm²）的变化,并行统计学分析。结果：光凝后FFA检查经组间两两比较,14、21和28d的早期荧光渗漏斑数/渗漏面积差异无统计学意义(P>0.05),14、21和28d与7d相比差异有统计学意义(P<0.05);7、14、21和28d早期和晚期荧光渗漏斑数差异无统计学意义(P>0.05)。激光斑视网膜的平均厚度与平均荧光渗漏面积有相关性（r=0.73,P<0.05）。结论：半导体激光诱导BN大鼠的CNV模型是可行的。FFA联合OCT可有效检测CNV的形成和变化。