种植受体血管内皮细胞在异种血管移植中的实验研究

目的　探讨种植受体血管内皮细胞在抗异种血管移植超急排斥反应 (HAR)方面的意义。方法　选用豚鼠→大鼠移植模型 ,先将分离、培养的大鼠动脉内皮细胞种植于去内皮的豚鼠动脉内壁 ,再将此豚鼠动脉植入大鼠体内 ,观察动脉血栓形成时间 ,并采用免疫组化技术检测了 Ig M、C3在移植后豚鼠动脉壁上沉积的情况。结果　已种植大鼠内皮细胞的豚鼠动脉血栓形成时间 (2 0 .3± 4.42 h)较植入大鼠体内的正常豚鼠动脉 (0 .35± 0 .2 84h)以及单纯去内皮豚鼠动脉血栓形成时间 (0 .16 5± 0 .0 77h)显著延长 (P<0 .0 0 1)。免疫组化结果显示 ,植入大鼠体内的正常豚鼠内皮细胞表面有 Ig M和 C3沉积 ,而预先种植大鼠内皮细胞的豚鼠动脉内壁无 Ig M和 C3沉积。结论　在异种供体血管壁上预先种植受者血管内皮细胞 ,可延长移植的异种供体血管通畅时间 ,该技术可能在抗异种血管移植 HAR方面具有重要意义     

The Effect of Total Blood Exchange with PHP Solution on Cardiac Xenotransplantation

Abstract: Prevention of hyperacute rejection is a difficult and unsolved problem in xenotransplantation. Natural antibodies and complement activation have been known to play an important role in the xenotransplantation between discordant species pairs. In the present study, total blood exchange (TBE) was performed with pyridox-alated-hemoglobin-polyoxyethylene conjugate (PHP) solution (Ajinomoto Co., Inc., Kawasaki, Japan) before cardiac xenotransplantation in order to remove the immunoglobulins and prolong xenograft survival time. Guinea pigs and rats were used as the discordant species combination for donor and recipient. Two groups were established: Group 1, untreated control (n = 8) and Group 2, TBT with PHP solution (n = 8). The exchange blood transfusion was carried out at the rate of 15–20 ml/h utilizing PHP solution using a blood pump. After the blood exchange was processed, hematocrit (Ht) levels dropped to 4 or 5%, and a cardiac xenotransplantation was performed within 24 h. The levels of serum IgA, IgM, and IgG were decreased to less than 25, 25, and 10% of the base line, respectively, after blood exchange. A mean xenograft survival time in Group 2 was prolonged to 472 ± 74 min and to 10.4 ± 1.8 min in Group 1 (p < 0.01). A titer of the anti-guinea pig lymphocytotoxic antibody in rat serum was decreased to almost nil. The data from this study suggest that total blood exchange with PHP solution may be useful in preoperative removal of xenograft antibodies in xenotransplantation.     

豚鼠至大鼠异种小肠移植超急性排斥的初步观察

目的 建立袖套法豚鼠至大鼠异种小肠移植模型,初步观察异种小肠移植超急性排斥反应的过程。方法 行异种异位全小肠移植,移植小肠脾性系膜上动脉（腹主动脉）与受体肾以下腹主动脉作端侧吻合,切除受体左肾,移植小肠肠系膜上静脉（门静脉）与受体左肾静脉行袖套吻合;在手术显策镜下观察超急性排斥的大体变化。结果 共实施异种小肠移植４０例,成功３４例,供受体手术时间平均１５０ｍｉｎ,血管吻合成功率达９０％。再灌流后１     

Placement of a subdural evacuating port system for management of iatrogenic hyperacute subdural hemorrhage following intracranial monitor placement

A 22-year-old man was admitted with a severe traumatic brain injury developed a hyperacute subdural hematoma (SDH) following attempted brain tissue oxygen monitor placement. This patient was successfully treated by placement of a subdural evacuation portal system (SEPS). The patient presented to a Level I trauma center after a severe bike versus auto accident. On admission, he was found to have a Glasgow Coma Scale (GCS) score of 3. The patient had small areas of intraparechymal hemorrhage as well as suspicion for diffuse axonal injury in the midbrain. Based on the patient’s GCS score, neurological monitoring was indicated as a part of his intensive care unit treatment, however a SDH occurred during an attempted placement of a brain tissue oxygen monitor. This iatrogenic hyperacute SDH after burr hole monitoring device placement was treated with a SEPS drain. The SEPS drain has been shown to provide complete and/or temporary decompression of liquefied SDH. To our knowledge, this is the first report of using the SEPS to treat iatrogenic SDH associated with an intracranial monitoring device. This technique should be added to the armament of treatment options for a neurosurgeon to treat or temporize a hyperacute SDH with increased intracranial pressure in specific patients.     

异种移植的研究进展

目的总结异种移植的研究现状与进展。方法复习国内外关于异种移植研究的相关文献并进行综述。结果超急性异种排斥反应是异种移植面临的巨大问题,器官或组织的供体经过基因修饰后,在一定程度上可以减轻超急性异种排斥反应。由于不同的器官具有不同的特性,目前异种器官移植移植物的存活时间存在较大差异。结论通过对相关异种移植实验研究的分析,可以全面地了解异种移植的研究背景,为异种移植提供合适的研究方向。将经基因修饰的动物作为异种器官或组织的供体,有望使移植物避免或减轻超急性异种排斥反应。     

r氐场强磁共振弥散加权成像在早期脑梗塞中的诊断价值

目的探讨低场强磁共振弥散加权成像在超急性期脑梗塞及急性期脑梗塞中的诊断价值。方法对58例急性期不同时间段的脑梗塞患者磁共振弥散加权成像（DwI）图像与常规扫描T1WI，T2WI和FIR信号图像进行对比分析。结果58例患者中，发病3h内共8例，其中3例DWI出现稍高信号，占38％；3～6h共10例，其中6例DWI见稍高信号，占60％；7～12h共28例，其中26例DWI见高信号，占92％；13～24h共12例，T2WI，FIR和DWI均见高信号占100％。结论低场强磁共振弥散成像与常规扫描对比，低场强磁共振弥散成像对早期脑梗塞有较高敏感性及特异性。     

普通CT在脑梗死超急性期的诊断价值

目的探讨普通CT对超急性期脑梗死的诊断价值。方法回顾性分析300例在发病后1～6h内应用常规CT扫描患者的临床表现和CT征象,所有病例均在发病24h后复查螺旋CT或MR证实为脑梗死患者。结果300例中出现异常征象者共有202例,超急性期脑梗死CT征象包括:脑实质局部密度轻度减低者126例,局部脑肿胀、邻近脑沟变浅、脑室变形变窄者52例,大脑中动脉密度增高者94例,豆状核密度减低108例,脑岛、最外囊和屏状核密度减低、灰白质界线模糊87例。结论超急性期脑梗死常规CT虽然征象轻微,但结合临床,具有一定的价值。     

超急性期脑梗塞常规CT检查与CT灌注成像的比较研究

目的：探讨常规CT与CT、灌注成像对超急性期脑梗塞的诊断应用价值。方法：对96例临床诊断超急性期脑梗塞的病人行常规CT头颅平扫及CT脑灌注成像,在常规轴面扫描后一般选取基底节层面,经肘静脉灌注对比剂,同时开始持续46S的单层连续动态扫描,重建46幅动态图像使用CT脑灌注软件包进行处理,获得灌注成像。计算最大峰值时间(PT),平均通过时间(MTT)和相对血流量(RF)。结果：早期常规CT头颅平扫,显示大脑中动脉高密度征,脑实质低密度征等共35例,占36．4％,CT灌注成像发现88例与临床症状相对应的灌注异常区,表现为达峰时间延长,另外8例未发现灌注异常区。结论：常规CT对超急性期脑梗塞的诊断,具有一定价值,但作用有限,在准确性远不能满足临床应用的需要。脑CT灌注成像已成为早期诊断超急性期缺血性脑血管病和指导临床治疗(尤其是溶栓治疗)的最佳方法。     

CT脑灌注成像在超急性期脑梗死中的应用

CT脑灌注成像(CTP)可以显示脑血流动力学信息,早期即可显示缺血的梗死灶和缺血性半暗带,预测可以存活的脑组织,对早期诊断和治疗脑梗死及判断预后具有重要价值。随着64层螺旋CT的广泛应用,明显缩短了扫描时间,CT平扫、CTP和CT血管造影(CTangiography,CTA)联合扫描20min内即可完成,而且利用CTA和平扫图像获得三维脑灌注血容量(perfused blood volume,PBV)成像,可以全面显示病灶范围,避免小病灶的漏诊。     

靶向慢病毒载体RNA干扰小鼠血管内皮细胞异种抗原的研究

目的 使用慢病毒介导的RNA干扰(RNAi)方法抑制小鼠血管内皮细胞异种抗原半乳糖α1,3-半乳糖(Galα1,3-Gal)的表达.方法 经体外设计合成针对α1,3-半乳糖基转移酶(α1,3-GT)mRNA的序列特异性小发夹RNA(shRNA),并构建携带α1,3-GT shRNA的重组慢病毒载体,以慢病毒感染小鼠血管瘤内皮细胞系EOMA细胞.采用荧光实时定量聚合酶链反应检测转染后的EOMA细胞α1,3-GT mRNA表达水平的变化;免疫荧光法和流式细胞术检测转染后的EOMA细胞异种抗原Galα1,3-Gal表达水平的变化.并将转染后的EOMA细胞与人血清混合培养,用四甲基偶氮唑盐比色法测定细胞存活率.结果 成功获得携带α1,3-GT shRNA的成熟重组慢病毒颗粒,转染EOMA细胞效率可达75%.与空白对照组、空转染组以及阴性siRNA对照组比较,重组慢病毒转染EOMA细胞后,能有效抑制α1,3-GT的表达,抑制率为88%(P＜0.05);Galα1,3-Gal抗原表达水平明显降低(P＜0.05);而空白对照组、空转染组和阴性siRNA对照组间的差异无统计学意义(P＞0.05).重组慢病毒转染后的EOMA细胞与人血清混合培养后的存活率较各对照组明显提高(P＜0.05).结论 成功构建靶向α1,3-GT基因的重组慢病毒载体,通过RNAi沉默α1,3-GT基因,抑制EOMA细胞异种抗原Galα1,3-Gal的表达,在体外实验中可减轻异种超急性排斥反应.