冰微粒致孔制备聚羟基丁酸酯(PHB)多孔支架

目的以冰粒子为致孔剂,用粒子滤出—冷冻干燥复合工艺制备PHB多孔支架。方法本实验以氯仿为溶剂,将PHB溶液浇入预先排列好的冰微粒空隙中,采用真空渗流方法制备冰微料-PHB复合体,液氮冷却成型后,用粒子滤出—冷冻干燥复合工艺制备多孔支架。通过扫描电镜(SEM)观测,研究该制备工艺对支架形貌的影响。结果制备的块状三维多孔支架孔径可调、孔隙结构良好、孔隙连通度高。结论本文工艺所制备的多孔支架无致孔剂残留,孔隙率高,孔隙连通度高,制备过程不会损害材料的生物相容性,可安全地用于组织工程可降解聚合物多孔支架的制备。     

Feasibility of establishing cerebral ischemia models by using aerocyst-blocking bilateral ascending pharyngeal artery of piglets Imaging assessment

BACKGROUND: The cerebral ischemia and ischemia/reperfusion animal models are used to simulate the human cerebrovascular diseases is one of the popular topics of neurological science recently. To study the pathophysiology, pathogenesis, prophylaxis and treatment of ischemic cerebrovascular diseases and to establish the ideal animal model that is the most similar to the human cerebral ischemia, are the topics that the people generally cared about. OBJECTIVE: To evaluate the effects of aerocyst-blocking bilateral ascending pharyngeal artery on the establishment of cerebral ischemia models by using digital subtraction angiography (DSA), magnetic resonance diffusion-weighted imaging (DWI) and magnetic resonance perfusion-weighted imaging (PWI). DESIGN: Repetitive measure animal experiment. SETTING: Zhongshan Hospital Affiliated to Dalian University. MATERIALS: The experiment was carried out in the Animal Laboratory (Provincial Laboratory), Zhongshan Hospital of Dalian Univeristy from January to May 2006. A total of 14 domestic piglets, of 6 months old, weighing 12–15 kg, of either gender, were selected from Animal Experimental Center, Dalian University. Multistar T.O.P digital subtraction angiography machine was provided by Siemens Company, German. METHODS: Aerocyst-blocking bilateral ascending pharyngeal artery was used to establish cerebral ischemia models. And then, Multistar T.O.P. DSA was used for imaging of cerebral vessels before blocking, during blocking and at 0.5 and 2 hours after ischemia perfusion. GE Signa 1.5 T supraconduction magnetic resonance imaging was used for DWI examination; in addition, PWI was used based on focal sites and areas. Otherwise, magnetic resonance imaging (MRI) was used to detect signal changes of T1WI and T2WI in ischemic areas. MAIN OUTCOME MEASURES: Analytic results of DSA, DWI, PWI and MRI. RESULTS: All 14 experimental piglets were involved in the final analysis. ① DSA: The blood flow of bilateral ascending pharyngeal arteries and its branch were blocked at blocking phase, which restored 0.5 and 2 hours after reperfusion. ② DWI and PWI: There were no observable abnormalities in PWI and DWI at pre-blocking. Abnormal increased signals were found on both DWI and PWI at during and post-blocking. There were reduction in ADC and rCBF and delay in rTTP at all time points except pre-blocking. ③ MRI: There were no abnormal signals observable at any time of pre- and post-blocking in T1WI and T2WI. CONCLUSION: It is feasible to establish this kind of animal experimental models, and it can simulate the ischemic state; meanwhile, the existence and extent can be showed directly by DSA, DWI, and PWI.     

留置双J管病人的观察与护理

双J管又称双猪尾管，因两端卷曲，每端形似猪尾而得名。由于其支架和内引流作用，能解除输尿管炎症、水肿造成的暂时性梗阻，防止术后伤口漏尿和输尿管狭窄。同时，集合系统不与外界直接相通，可避免肾造瘘所引起的出血、感染，因无外引流管的限制和不适感，病人可早期下床活动，有利于术后康复。2004年7月-2005年2月我院先后为58例病人应用双J导管．效果良好，现报告如下。     

小儿先天性髋关节脱位近年来应用术式的演变及其评估

本文介绍本院近４年来小儿先天性髋脱位治疗应用术式的演变。由２０多年来一直喜欢用骨盆截骨术演变为近１年来用得最多的是造盖术。近４年共手术４６３例，５６５髋。实践证明：比起骨盆截骨术，造盖术显得更简便，侵袭小，不需二次手术拔除内固定针。因在我国大龄髋脱位偏多，造盖术更适合我国国情。经过一些改进，可以克服造盖折断和吸收问题。     

SODIUM EFFECTS ON THE FIBRILLATORYPROPENSITY OF NON-IONIC CONTRAST MEDIA

Removing sodium from standard ionic contrastmedia markedly increases the incidence of ventricu-lar fibrillation in patients undergoing coronary arvgiography. Newer nonionic contrast media, Iopa-midol (IOP), Iohexol (IOH) and Ioversol (IOV),contain only trace amounts of sodium. To determinewhether sodium influences the fibrillatory propen-sity of nonionic contrast media, we measured theprolongation in QT interval and performed program-med electrical stimulation with l,2 and 3 ventricularextra stimuli in 40 dogs during 4 ml intracoronaryinjections of IOP, IOH and IOV. Solutions of eachcontrast media with added NaCI at concentrations of0.225To, 0.45% and 0.970 were compared to stockcontrast media. The addition of NaCI markedlyincreased the amount of QT interval prolongationproduced by each contrast media. With IOP, theamount of QT interval prolongation was 40+11msec with standard IOP but was 58+11 msec with0.225'70 NaCI/IOP, 84+17 msec with 0.45'To NaCI/IOP, and 132+42 msec with 0.970 NaCl/IOP(P相似文献   

受体介导内吞和自噬同凋亡的关系

目的 观察刀豆素A(ConA)与小鼠腹腔巨噬细胞表面ConA受体结合、内吞、转运及巨噬细胞自噬、凋亡的形态学变化，以探讨受体介导内吞与自噬体形成和细胞凋亡之间的关系。方法 用辣根过氧化物酶(HRP)标记ConA(ConA-HRP)与小鼠腹腔巨噬细胞共孵育，不同时间取出部分巨噬细胞，制备电镜标本，观察。结果透射电镜观察表明：ConA的内吞属于受体介导内吞；形成的内吞体有泡状、管状及双层膜的线状等形式；双层膜的线状结构包裹部分胞质和细胞器，形成自噬体；自噬体与溶酶体融合，而后巨噬细胞凋亡。结论受体介导内吞和自噬同凋亡之间存在一定的关系。     

六味地黄汤对实验性糖尿病大鼠心、肝、肾组织中过氧化氢酶活性和过氧化脂质含量的影响

用四氧嘧啶诱导雄性Ｗｉｓｔａｒ大鼠为模型进行研究．结果发现，四氧嘧啶大鼠血糖明显升高，且心、肝、肾组织中过氧化氢酶活性较正常组明显降低，过氧化脂质含量在心、肝组织中明显增高，过氧化脂质与过氧化氢酶比值在心、肝、肾组织中均明显高于正常组，表明糖尿病状态下大鼠心、肝、肾组织中均自由基生成增多，氧化损伤加重．经六味地黄汤治疗后，血糖明显下降，但心、肝、肾组织中的过氧化氢酶活性无改变；而心肌中过氧化脂质含量和过氧化脂质与过氧化氢酶比值则明显降低，过氧化脂质含量和过氧化脂质与过氧化氢酶比值在肝、肾组织中无变化，表明六味地黄汤能明显清除心肌中自由基，抑制心肌中脂质过氧化，且此作用并不是通过提高过氧化氢酶活性来达到．     

神效止痛膏的镇痛作用

用二甲苯所致的急性炎症模型观察了神效止痛膏的抗急性炎症作用．用扭体法、热板法观察了神效止痛膏对小鼠的镇痛作用．结果表明，神效止痛膏有很好的镇痛作用．     

基于混合遗传算法的心脏病决策支持系统研究

将遗传算法和 BP算法相结合 ,建立了一个基于混合遗传算法的心脏病决策支持系统来鉴别诊断五种常见心脏病 (冠心病 ,高血压性心脏病 ,风湿性心脏病 ,慢性肺原性心脏病和先天性心脏病 )。一个含有 35 2份心脏病的数据库用来构建和测试了该系统。实验结果表明 ,构建的系统对这五种心脏病均有较好的诊断识别率 ,系统的平均识别准确性达 90 .6 % ,各疾病的用户准确性和程序准确性均大于 85 .0 % ,表现出良好的心脏病的临床诊断决策支持能力