人表皮细胞与角膜上皮细胞蛋白质组的差异表达初步研究

目的：应用蛋白质组技术比较人表皮细胞与角膜上皮细胞之间的蛋白质表达差异。方法：实验于2005-11，2006-10在中山大学中山眼科中心国家眼科学重点实验室完成。分别培养人表皮细胞与角膜上皮细胞，裂解原代细胞抽提总蛋白，精确定量后进行双向电泳，扫描电泳凝胶获得二维总蛋白图谱。图谱使用软件辅助比较分析，找出差异表达点，从凝胶中抠取差异点，胶内酶解后用基质辅助激光解吸附，电离飞行时间串级质谱法鉴定差异蛋白。结果：人表皮细胞与角膜上皮细胞蛋白质凝胶分析获得600余个清晰的蛋白质斑点，在比较分析出的26个差异点中初步鉴定出4个差异表达蛋白，分别是细胞内氯离子通道1、Psodasin、乳酸脱氢酶B和丝氨酸蛋白酶抑制因子。结论：人表皮细胞与角膜上皮细胞在蛋白质表达上有较高的相似性以及较好的可比性，为探索表皮细胞横向分化成角膜上皮细胞的分子机制做出了有益的尝试，并提供了具有一定可操作性的实验方法。     

DIGITAL ISCHAEMIA: AN UNUSUAL PRESENTATION OF DYSBARISM

SUMMARY Dysbaric symptoms following ascent from a scuba dive are due to symptomatic nitrogen or air emboli with clear patterns of associated injury. This case report highlights an unusual presentation of dysbaric injury treated successfully with a prostacyclin analogue.     

Normal and stenotic renal arteries: experimental balloon-expandable intraluminal stenting

Elastic recoil of the vessel wall is a common cause of failure of percutaneous transluminal angioplasty in renal arteries. To oppose such recoil, balloon-expandable metal stents were implanted in artificially stenotic renal arteries in pigs and normal renal arteries in dogs and pigs. The stents were then examined angiographically and histologically at regular intervals. All stents were completely covered with endothelialized neointima in 3 weeks. There was no difference in intimal thickness between the stenotic and nonstenotic renal arteries. A large stent diameter and a large open or nonmetal surface may cause less intimal hyperplasia, but nonturbulent, fast arterial flow is probably the most important factor in ensuring long-term patency of the vessel.     

双嘧达莫在汞电极上的电化学行为和吸附性质

在NaOH底液中,双嘧达莫在汞电极上有一不可逆的线性扫描还原峰,E_PC=—1.39V(vs饱和Ag/AgCl)。该峰具有明显的吸附性。当搅拌富集时间较长、双嘧达莫的浓度较小、扫描速度较快时,电极反应几乎完全为吸附态的双嘧达莫所控制。选相交流伏安等实验表明,吸附型体为双嘧达莫中性分子。测得该体系的电子转移数n为4,不可逆吸附的αn_α值为1.72。探讨了双嘧达莫的电极反应机理,建立了用吸附伏安法测定双嘧达莫的最佳条件。     

Differential function of CD80- and CD86-transfected human melanoma cells in the presence of IL-12 and IFN-gamma

Introduction of co-stimulatory molecules like CD80 and CD86 represents a means to augment the immunogenicity of tumor cells and to induce immune responses directed at tumor antigens. Here we compared CD80- and CD86-transfected human melanoma cells to induce primary immune responses by their capacity to promote proliferation of human allogeneic resting T lymphocytes. CD80- and CD86-transfected SkMel63 melanoma cells induced T cell activation to a comparable degree, which was found to be independent of the cell surface density of these co- stimulatory molecules. Co-expression of CD80 and CD86 did not result in a synergistic increase in T cell proliferation. Both CD80 and CD86 transfectants induced the proliferation of isolated CD4+ or CD8+ T cells. Exogenous IL-2, IL-4 and tumor necrosis factor-alpha respectively enhanced primary T cell proliferation independent of CD80 or CD86 expression. Interestingly, differential activities of CD80 and CD86 were observed following stimulation of resting T cells in the presence of IL-12. Whereas IL-12 increased T cell proliferation in the presence of CD86-transfected melanoma cells, it exhibited an inhibitory function in the presence of CD80-expressing SkMel63 cells. Experimental evidence indicates that this inhibitory effect was mediated by IFN- gamma since (I) IFN-gamma secretion of stimulated T cells was augmented by IL-12, (II) exogenous IFN-gamma also inhibited T cell proliferation induced by CD80- but not CD86-transfected SkMel63 cells and (III) the inhibitory effect of IL-12 was blocked by an anti-IFN-gamma mAb.