组织工程用外科植入物-高分子材料的加工、改性及应用

介绍了组织工程用外科植入物-生物医用高分子材料基本情况．重点从三个方面介绍了我们的工作，首先我们合成了三种可降解材料：聚羟基烷酸酯、两亲性聚氯酯弹性体、可注射性水凝胶．利用各种方法制造了多种复杂形状的组织工程支架，并对医用支架材料表面进行了改性。     

Performance and comparison of the Cockcroft-Gault and simplified Modification of Diet in Renal Disease formulae in estimating glomerular filtration rate in a Chinese Type 2 diabetic population.

AIMS: Our aim was to assess performances of the Cockcroft-Gault and simplified Modification of Diet in Renal Disease (MDRD) formulae in estimating glomerular filtration rate (GFR) in Chinese diabetic populations and their association with vascular risks. METHODS: A total of 1009 patients with Type 2 diabetes were categorized into low estimated GFR groups (GFR < 60 ml/min/1.73 m(2)) and control groups by the two equations. The performances of these formulae were assessed at different stages of kidney function. Carotid artery intima-media thickness (IMT) and the prevalence of diabetic retinopathy or albuminuria were compared among the groups. The ability of these formulae to identify established vascular risk markers using sensitivity, specificity, positive and negative predictive values were also compared. RESULTS: The prevalence of low estimated GFR was 32.7% with the Cockcroft-Gault formula and 5.2% with the MDRD formula, respectively. In low estimated GFR subjects by the MDRD formula, IMT was significantly thicker than those by the Cockcroft-Gault formula (1.2 mm vs. 1.0 mm; P < 0.05), with a higher prevalence of albuminuria (78.4 vs. 52.8%, P < 0.05) and diabetic retinopathy (46.5 vs. 30.5%; P < 0.05). The Cockcroft-Gault formula gave a specificity of 71.7% and a sensitivity of 37.0%, and the MDRD formula gave a specificity of 96.6% and a sensitivity of 7.9% in estimating low GFR relevant for established vascular risks. CONCLUSIONS: These formulae performed differently in Chinese diabetic populations. The simplified MDRD formula is minimally superior to the Cockcroft-Gault formula for its high specificity and positive predictive values in estimating low GFR relevant for vascular risks.     

上睑下垂的术前评估及改良提上睑肌缩短术矫治的疗效评价

目的评价改良提上睑肌缩短术矫治上睑下垂的效果。方法采用改良提上睑肌缩短术[此改良术式与常规术式不同之处在于增加分离提上睑肌腱膜的长度(22mm)和宽度(16mm),腱膜在睑板上固4对缝线,以增加其牢固度],共治疗上睑下垂57例68眼,其中轻度13例13眼,中度38例47眼,重度6例8眼。结果术后4～36个月随访,治愈48例59眼,欠矫9例9眼,无过矫病例。结论该提上睑肌缩短术与常规手术比较有改进,术后的睑缘高度易保持在上方角膜缘,弧度与健侧对称,不易形成眼角畸形,能较好提高矫治效果。     

聚丙烯改性研究

采用马来酸酐、二甲基丙烯酸乙二醇酯、三羟甲基丙烷三基丙烯酸酯对聚丙烯进行改性。以自由基反应机理为基础，讨论了引发剂用量、反应时间、改性试剂的种类、用量等因素对改性ＰＰ凝胶含量及性能的影响，提出了力学性能的优选条件。得到了力学性能优良的改性ＰＰ，为其进一步功能化提供了理论参考。     

金银花nrDNA ITS区聚合酶链反应条件的研究

目的:金银花nrDNA ITS区序列G C含量为68%,用常规的PCR方法扩增效果差.本研究通过改变扩增程序及使用改性剂的方法显著提高了金银花nrDNA ITS区的扩增效率.方法:分别从金银花叶及药材中提取总DNA,通过优化扩增条件,对nrDNA ITS区进行扩增,并比较了两种优化方法的差别及适应性.方法1:提高变性温度至97℃;方法2:添加混合改性剂(DMSO 4%-甘油10%).结果:与方法1相比,方法2可降低变性温度5 ℃,升高退火温度9 ℃,降低镁离子浓度至0.5 mmol/L,降低Taq DNA聚合酶用量至0.1 U(30 μl体系),PCR产物量显著提高,且可消除植物DNA粗提物中杂质的干扰.结论:通过提高退火温度及添加改性剂可克服高G C含量金银花nrDNA ITS区序列扩增的困难,该方法的建立有助于解决植物来源DNA模板的PCR扩增问题.     

LOX-1介导ox-LDL诱导的血管内皮细胞MCP-1的表达

目的：观察血凝素氧化低密度脂蛋白受体-1（LOX-1）对氧化LDL（ox-LDL）诱导的人脐静脉内皮细胞(human unbilical vein endothelial cells, HUVECs)表达单核细胞趋化蛋白（monocyte chemoattractant protein-1, MCP-1）基因及蛋白的影响。 方法： 用RT-PCR和Western blot的方法观察ox-LDL对培养的HUVECs表达LOX-1和MCP-1基因及蛋白的影响，然后用LOX-1的受体阻滞剂爱兰苔胶（carrageenan） 和聚肌苷酸［polyinosinic acid，poly(I)］与HUVECs预先作用后，再观察内皮细胞表达LOX-1和MCP-1基因和蛋白的变化。 结果： 用不同浓度的ox-LDL（0 mg/L、10 mg/L、20 mg/L 、50 mg/L、100 mg/L）与HUVECs培养24 h后，LOX-1和MCP-1的mRNA和蛋白的表达明显增加，呈浓度依赖性；用Carrageenan 和polyinosinic acid与HUVECs预先作用2 h后，再加入50 mg/L的ox-LDL培养24 h，与未加Carrageenan和polyinosinic acid相比，HUVECsLOX-1和MCP-1的mRNA和蛋白的表达明显减少。 结论： ox-LDL可以调节培养的HUVECsLOX-1和MCP-1基因和蛋白的表达，LOX-1作为ox-LDL的特异性受体，可能介导了ox-LDL诱导血管内皮细胞分泌MCP-1，从而在动脉粥样硬化的发生发展中起着重要的作用。     

血凝素样氧化低密度脂蛋白受体-1与动脉粥样硬化的研究进展

Lectin-like oxidized low density lipoprotein receptor-1 (LOX-1 } is a type-Ⅱ membrane protein belonging to the C-type lectin family molecules, which acts as a cell surface endocytosis receptor for atherogenic oxidized LDL (Ox-LDL）. LOX-1 supports the binding internalization and proteolytic degradation of oxidized LDL, but not of significant amounts of acetylated LDL. LOX-1 is initially synthesized as a 40 kD precursor protein with N-linked high mannose-type carbohydrate, which is further glycosylated and processed into a 48-kD mature form. In vivo, endothelial cells that cover early therosclerotic lesions, intimal macrophages and smooth muscle cells in advanced atherosclerotic plaques express LOX-1. LOX-1 is cleaved at membrane proximal extracellular domain and released from the cell surface. Measurement of soluble LOX-1 in vivo may provide novel diagnostic strategy for the evaluation and prediction of atherosclerosis and vascular diseases.     

氧化修饰低密度脂蛋白对内皮细胞功能的影响

目的 观察氧化修饰低密度脂蛋白（ox-LDL）对内皮细胞NO／ET-1、t-PA／PAI-1合成、细胞表面细胞间黏附分子-1（ICAM-1）表达的影响。方法 采用培养的人脐静脉内皮细胞（HUVECs），在分另0加入不同浓度ox-LDL（50、100、150、200mg／L）孵育24h后，观察培养液中NO、ET-1、t-PA、PAI-1水平及细胞表面ICAM-1的表达。结果 ox-LDL可显著抑制NO、t-PA的合成。ox-LDL还可明显增加ET-1、PAI-1的分泌及诱导细胞表面ICAM-1的表达。结论 ox-LDL对内皮细胞具有明显的细胞毒作用，它对NO／ET-1、t-PA／PAI-．1及ICAM-1表达的影响可能是其致动脉粥样硬化发生的重要机制之一。