重组蛇毒纤溶因子修饰聚氨酯人工血管的犬颈动脉置换实验

OBJECTIVE: To evaluate the implantation effect of artificial vascular grafts with recombinant fibrinolytic enzyme factor II (rF II)-immobilized lumina in animal test. METHODS: Four mm internal diameter (ID) polyurethane (PU) artificial vascular grafts were prepared by dipping and leaching method. The micro-pore size and morphology of the graft walls were observed by SEM. The graft lumina were immobilized with rF II. Twenty hybrid male dogs [weighing (20 +/- 1) kg] were used for animal model of carotid artery defect and were randomly divided into 3 groups: rF II -immobilized PU group, no rF II -immobilized PU group and expanded polytetrafluoroethylene (ePTFE) group. The vascular grafts were implanted for repairing injured segments of carotid artery in dogs. The general health state of animals was recorded. At 30 days and 60 days, the patency rate of every group was calculated. At 60 days IDs were measured, cell proliferation in neointima was inspected by light microscope, morphology on neointima was observed by SEM. RESULTS: The ID of the PU vascular grafts was (3.74 +/- 0.06) mm, wall thickness was 0.4-0.6 mm, the wall density was 0.25 g/cm3, the porosity was 79.8%, racical compliance was 8.57%/100 mmHg. In the wall, micropores were well distributed and opened-pores structure was observed. Pore size was (140 +/- 41) microm in the outside layer, pore size was (100 +/- 3) microm in the inside layer, thickness ratio of outside / inside layers was 2 : 1, the pore size was (40 +/- 16) microm on the lumina surface. After operation the wounds on neck healed, all the animals survived and had no complication. At 30 days and 60 days after implantation, the patency rate for rF II -immobilized PU group were 100% and 66.7%, for no rF II -immobilized PU group were 66.7% and 33.3%, and for ePTFE group were 67.7% and 0 respectively, but at 60 days there were thrombosis at anastamotic sites of some grafts occluded. Before operation the IDs for rF II-immobilized PU group, no rF II -immobilized PU group and ePTFE group were (3.74 +/- 0.06), (3.74 +/- 0.06) and (4.00 +/- 0.03) mm, at 60 days after operation the IDs were (4.51 +/- 0.05), (4.31 +/- 0.24) and (4.43 +/- 0.12) mm respectively, showing no statistically significant differences between 3 groups (P > 0.05). Histological inspection indicated that at 15 days a layer of plasma protein deposited on the lumina, at 30 days some cells adhered to the lumina, at 60 days neointima could be observed on the lumina. Thickness of the neointima became larger with implantation time. At 60 days neointima thickness at proximal end, middle site and distal end of graft were (560 +/- 22), (78 +/- 5) and (323 +/- 31) microm respectively for rF II -immobilized PU group. The results of SEM showed that neointima surface consisted of flat and long cells which long axes ranged with blood flow direction and was similar to lumina morphology of carotid artery of dog. CONCLUSION: Immobilization of rF II to lumina of grafts could enhance fibrinolytic activity and inhibited formation of thrombo-embolia which led to an increase in patency rate after implantation.     

变应性鼻炎患者外周血白介素4和13的检测

Th1／Th2平衡和复杂的细胞因子网络学说是变应性鼻炎发病机制较新的观点。虽然IL4被认为是生成Th2型细胞的主要介质之一，但IL-13也日益受到重视。有研究表明，IL4缺陷的转基因小鼠也能产生IgE反应，而IL-4／IL-13都缺陷的转基因小鼠不能产生IgE反应。IL—13缺陷小鼠的T细胞不能产生Th2型细胞因子。阻断IL-13可显著抑制抗原导致的气道高反应。本研究通过采用流式细胞仪检测变应性鼻炎患者细胞内IL4、IL-13、干扰素-γ（IFN-γ）的表达，以及酶联免疫吸附法（enzyme linked immunosorbent assay，ELISA）检测血清中IL4、IL-13含量，以探讨变应性鼻炎的发病机制。     

亲水性聚氨基酸膜对药物释放的影响

测定氟尿嘧啶，氢化可的松琥珀酸钠，博来霉素和丝裂霉素４种药物对亮氨酸－谷氨酸甲酯－谷氨酸共聚折膜的药物渗透系数，研究聚氨基酸包膜药片的体我释药规律，结果表明：聚氨基酸膜谷氨酸含量越大，药物对其的渗透系民越大药物相对分子质量增大，对聚氨酸膜的渗透系九值则趋小；     

胚胎干细胞体外诱导分化为CD34+造血前体细胞

【目的】胚胎干细胞 (embryonicstemcell,ES)体外诱导分化 ,制备CD34 造血前体细胞。【方法】胚胎干细胞在含甲基纤维素培养液中分化形成胚胎体 (embryoidbody ,EB) ,然后加入造血刺激因子诱导产生CD34 造血前体细胞 ,间接免疫荧光及流式细胞仪检测分化结果。【结果】胚胎干细胞分化第 9～ 15天均有CD34 细胞 ,第 13天比例最高 ,可达 17 36 %。【结论】胚胎干细胞分化成胚胎体 ,在造血刺激因子的存在下 ,可大量获得CD34 造血前体细胞。     

健康人外周血单个核细胞体外诱导分化内皮祖细胞

[目的]将外周血单个核细胞诱导分化为内皮祖细胞,为冠心病缺血心肌血管新生提供理想的种子细胞来源.[方法]收集健康成人外周血,通过Ficoll离心法获得外周血单个核细胞,置于纤维连接蛋白预衬的EGM-2培养基中加以诱导,并通过相差显微镜和免疫荧光标记等方法对诱导分化后的细胞进行形态学观察和鉴定.[结果]在上述诱导分化条件下,外周血单个核细胞分化成为内皮祖细胞,倒置荧光微镜下呈典形的"纺锤样"梭形细胞,ac-LDL吞噬及lectin抗体荧光标记双阳性,FLK-1和VWF免疫荧光抗体染色均为阳性.[结论]成人外周血单个核细胞在特定培养条件下可诱导分化成为内皮祖细胞,内皮祖细胞可作为冠心病缺血心肌血管新生的种子细胞.     

18-甲基炔诺酮-聚氨基酸微球的制备与体外释药实验

 本文报告了以白氨酸-谷苄共聚物为基体的18-甲基炔诺明緩释葯物微球的制备方法， 讨论了聚合物粘度、有机相/水相比例、分散剂液溶度、搅拌速度等对葯球球径的影响。本文还对4种不 同比例的基酸共聚物制备的药物微球进行了体外释葯实验，研究表明，释葯速率近似与释葯时间的1/ 2次方成反比。根据Higuchi方程式，我们计算了扩散糸数。释葯速率主要取决于缓释微球的球径和扩散 系数，     

喜树碱核壳型纳米胶束的制备及体外性能评价

目的：制备喜树碱/聚乙二醇-聚谷氨酸苄酯（CPT/PEG-PBLG）纳米胶束并考察其载药特性及体外性能。方法：采用膜透析结合冷冻干燥法制备CPT/PEG-PBLG纳米胶束,通过体外试验研究其释药特性,并考察胶束对HepG-2癌细胞的细胞毒性。结果：PEG-PBLG纳米胶束能包埋疏水性药物喜树碱,BLG嵌段摩尔比为35%的EG-5载药率达11.13%;CPT/PEG-PBLG纳米胶束的体外释放具有突释与缓释特性并在碱性介质中释放速度加快,EG-5载药胶束在pH 1.1累计释药率60.34%,而在pH 10.0时则为73.72%;当喜树碱质量浓度≤50 mg·L^-1时,CPT/PEG-PBLG胶束对HepG-2癌细胞的毒性远低于相应浓度的喜树碱阳性组（P<0.01）。结论：CPT/PEG-PBLG纳米胶束制备工艺简单,安全无污染,可降低喜树碱的细胞毒性,具有较好的临床应用价值。     

聚氨酯—聚硅氧烷共聚物的表面性质与抗凝血性

本文通过衰减全反射红外光谱,透射电镜,扫描电镜,固-液接触角等分析测试研究了聚氨酯-聚硅氧烷共聚物的表面微观形态和表面性质,同时使用Lee White凝血时间测定和血小板扩张试验评价了聚合物的抗凝血性。实验结果表明,聚氨酯-聚硅氧烷共聚物具有硬段微区(30～60(?))-聚醚软段相的微相分离结构以及聚二甲基硅氧烷-聚氨酯基体的微相分离结构,同时聚氨酯-聚硅氧烷共聚物的临界表面张力在24～27达因/厘米,共聚物的抗凝血性既优于聚氨酯。又优于聚硅氧烷。     

动物多糖的分离纯化方法

本文综述动物多糖的各种分离纯化方法,并分析各方法的特点以及适用范围.