卡巴胆碱抑制肿瘤坏死因子所致微血管内皮细胞通透性增高

目的探讨卡巴胆碱对肿瘤坏死因子-α（tumor necrosis factor-α，TNF-α）诱导的增加微血管通透性的作用。方法采用FITC标记白蛋白漏出法、考马斯亮蓝染色法观察卡巴胆碱对TNF-α诱导微血管内皮细胞通透性，细胞形态和细胞骨架变化的影响。结果与对照组比较，TNF-α明显增加微血管内皮细胞通透性（P〈0．05），诱导细胞皱缩，细胞间隙增大和细胞骨架排列紊乱。给予卡巴胆碱可以明显抑制TNF-α诱导微血管内皮细胞通透性增加，并呈剂量依赖性，同时可以使细胞间隙明显减小，细胞骨架排列有序。结论卡巴胆碱可能通过抑制TNF-α对细胞骨架的损伤，进而抑制微血管通透性增加。     

老龄大鼠内侧隔核TrkB mRNA的表达及人参皂甙的保护作用

目的:探讨人参皂甙对老龄大鼠内侧隔核TrkB mRNA表达的影响,为老年记忆减退性疾病的发病机制及人参皂甙的临床应用提供分子生物学基础。方法:选用Wistar大鼠,分成青年组、老龄组、给药组,采用原位杂交组织化学方法检测大鼠内侧隔核TrkB mRNA含量的变化情况。结果:老龄组内侧隔核TrkB mRNA阳性反应物的平均灰度值与青年组相比呈非常显著增高,而给药组的平均灰度值比老龄组呈显著降低。结论:老龄时内侧隔核TrkB mRNA表达低于青年组,而给药组较老龄组明显增加。说明人参皂甙具有增强TrkB mRNA表达,防止中枢神经系统神经元退行性改变的作用。     

Neuroprotective effects of IGF-I against TNFalpha-induced neuronal damage in HIV-associated dementia

Human immunodeficiency virus type 1 (HIV-1) infection often results in disorders of the central nervous system, including HIV-associated dementia (HAD). It is suspected that tumor necrosis factor-alpha (TNFalpha) released by activated and/or infected macrophages/microglia plays a role in the process of neuronal damage seen in AIDS patients. In light of earlier studies showing that the activation of the insulin-like growth factor I receptor (IGF-IR) exerts a strong neuroprotective effect, we investigated the ability of IGF-I to protect neuronal cells from HIV-infected macrophages. Our results demonstrate that the conditioned medium from HIV-1-infected macrophages, HIV/CM, causes loss of neuronal processes in differentiated PC12 and P19 neurons and that these neurodegenerative effects are associated with the presence of TNFalpha. Furthermore, we demonstrate that IGF-I rescues differentiated neurons from both HIV/CM and TNFalpha-induced damage and that IGF-I-mediated neuroprotection is strongly enhanced by overexpression of the wt IGF-IR cDNA and attenuated by the antisense IGF-IR cDNA. Finally, IGF-I-mediated antiapoptotic pathways are continuously functional in differentiated neurons exposed to HIV/CM and are likely supported by TNFalpha-mediated phosphorylation of I(kappa)B. All together these results suggest that the balance between TNFalpha and IGF-IR signaling pathways may control the extent of neuronal injury in this HIV-related experimental setting.     

银杏叶提取物对在体缺血保存再灌注后肺组织ICAM-1和P-选择素基因mRNA表达的影响

目的 探讨银杏叶提取物对在体缺血冷藏再灌注后肺组织ICAM-1和P选择素基因mRNA表达的影响。方法 新西兰白兔30只。随机分为3组：对照组、LPD组和GBE组．建立兔在体缺血冷藏再灌注模型，对照组左肺不灌注肺保护液，阻断左肺门后直接将左肺下叶载体冷藏于10℃肺保存器内2h，再灌注2h；LPD组左肺门阻断后经肺动脉灌注LPD液，余同对照组；GBE组灌注液为合银杏叶提取物（Ginkgo Biloba Extract，GBE）的LPD液，余同LPD组。分别于左肺门阻断前、缺血2h、再灌注2h取左肺组织，RTPCR技术检测P-选择素和ICAM-1基因mRNA的表达；免疫纽化技术检测P-选择素和ICAM-1基因蛋白质产物量。结果 三组在缺血前及缺血2h再灌注前P—selectin基因mRNA表达量及其蛋白质产物免疫组化评分组间均未有显著性差异。再灌注2h后，GBE组P—selectin基因mRNA表达量厦其蛋白质产物免疫组化评分显著低于LPD组和对照组。，缺血前，所有三组ICAM—1基因mRNA表达量均未有显著性差异，在缺血2h后再难注前及再灌注2h后，ICAM—1基因mRNA表达量及其蛋白质产物免疫组化评分在GBE组均显著低于对照组和LPD组。结论 银杏叶提取物可抑制P—selectin和ICAM—1基因mRNA的表达上调，使肺组织P—selectin和细胞间粘附分子-1蛋白产物减少，从而减轻保存肺的缺血再灌注损伤。银杏叶提取物作为肺保护液添加剂，在进一步研究后可以试用于临床肺移植，为中药提取物的开发应用展示了光明的前景。     

马桑内酯致痫后大鼠海马生长抑素mRNA表达的变化

为探讨马桑内酯致痫与生长抑素的关系，用原位杂交组织化学法研究了马桑内酯致痫后大鼠海马生长抑素ｍＲＮＡ阳性神经元的变化，结果表明：致痫组大鼠ＣＡ１，ＣＡ２区及齿状回生长抑素ｍＲＮＡ的反应明显增强，以上各区的中，小神经内生长抑素ｍＲＮＡ神经元的数目及强度明显高于正常对照组，两者有显著性差异。     

The effect of surface sugars on liposomes in immunopotentiation

The effect of surface sugars of liposomes on the immunological responses to entrapped antigen has been investigated. alpha-Mannose and beta-galactose were grafted on the surface of liposomes containing lysozyme by covalent coupling of p-aminophenyl-D-glycosides to phosphatidyl ethanolamine liposomes using glutaraldehyde. Subcutaneous administration of antigen entrapped in beta-galactose liposomes stimulated an antibody response comparable to that elicited by sugar-free neutral liposomes. However, alpha-mannose bearing liposomes with entrapped lysozyme elicited an immune response similar to that induced by lysozyme in saline. Based on these observations it is suggested that alpha-mannose liposomes, that are specifically recognized by macrophages, are taken up rapidly by receptor mediated endocytosis and that the entrapped antigen is then rapidly degraded, resulting in low antibody production.