大肠肿瘤组织中EB病毒的原位杂交检测

目的：探讨EB病毒感染与人大肠癌发生的关系。方法：用原位分子杂交法对130例人大肠癌标本中EB病毒小分子RNA片段进行检测。结果：130例标本中有6例（4.48％）癌组织呈阳性反应，其中4例为男性，4例有明显淋巴细胞浸润。结论：EB病毒感染可能与我国部分大肠腺癌的发生有关，肿瘤细胞间质中大量淋巴细胞浸润可能是EB病毒感染的重要病理学特征。     

海人酸致大鼠海马结构GABA_B受体亚单位表达的研究

目的:探讨海人酸诱导大鼠颞叶癫(EP)发作后2种γ-氨基丁酸(GABA)受体亚单位GABABR亚单位1a(GBR1a)和GABABR亚单位2(GBR2)在EP发生、发展中的作用。方法:运用原位杂交及免疫组化法,检测EP发作后GABABR亚单位mRNA及蛋白在海马的表达。结果:致早期CA1和CA3区2种亚单位mRNA表达持续低下后逐渐增加,DG区则暂时性下降后很快回升;而免疫反应早期却未见明显改变,随后CA1和CA3区表达处于低水平,DG区和颞叶皮质表达下降后很快恢复。结论:致后2种GABAB受体亚单位基因和蛋白表达上调为颞叶EP的内源性自我保护机制。     

Stereoselective metabolism of lansoprazole by human liver cytochrome P450 enzymes.

The stereoselective metabolism of lansoprazole enantiomers was evaluated by incubation of human liver microsomes and cDNA-expressed cytochrome p450 (p450) enzymes to understand and predict their stereoselective disposition in humans in vivo. The intrinsic clearances (Clint) of the formation of both hydroxy and sulfone metabolites from S-lansoprazole were 4.9- and 2.4-fold higher than those from the R-form, respectively. The sums of formation Clint of both metabolites were 13.5 and 57.3 microl/min/mg protein for R- and S-lansoprazole, respectively, suggesting that S-lansoprazole would be cleared more rapidly than the R-form. The p450 isoform selective inhibition study in liver microsomes, and the incubation study of cDNA-expressed enzymes, demonstrated that the stereoselective sulfoxidation is mediated by CYP3A4 and that the hydroxylation is mediated by CYP2C9 and CYP3A4 as well as by CYP2C19. Total Clint values of hydroxy and sulfone metabolite formation catalyzed by all these p450 enzymes were consistently higher for S-lansoprazole than for the R-form. The CYP3A4 produced the greatest difference of Clint between S- and R-enantiomers, mainly due to a difference of sulfoxidation metabolism (Clint 76.5 versus 10.8 microl/min/nmol of p450, respectively), whereas CYP2C19-catalyzed hydroxylation resulted in a minor difference of Clint between S- and R-enantiomers (179.6 versus 143.3 microl/min/nmol of p450, respectively). However, the affinity of CYP2C19 on hydroxylation was 5.7-fold higher for S-enantiomer than for the R-form (Km 2.3 versus 13.1 microM), suggesting that the role of CYP2C19 on stereoselective hydroxylation would be more prominent at concentrations around the usual therapeutic level. These findings suggest that both CYP2C19 and CYP3A4 are major enzymes contributing to the stereoselective disposition of lansoprazole, but stereoselective hydroxylation of lansoprazole enantiomers is mainly influenced by CYP2C19, especially at the usual therapeutic doses.     

人精浆对不同丝裂原诱导淋转反应的影响

本文通过人精浆对PHA、ConA和PWM三种丝裂原诱导淋巴细胞转化反应的影响,间接了解HSP对T辅助、T抑制和B淋巴细胞功能的影响,结果发现不同浓度的精浆对三种丝裂原诱导的淋转反应均有明显抑制作用(P<0.05),且三种浓度HSP的抑制作用在无显著性差异(P>0.05);中浓度的精浆对PHA、ConA和PWM诱导转反应的抑制率分别为69.7、51.7和48.3％,说明精浆对机体的T辅助、T抑制性和B淋巴细胞功能均有明显的抑制作用。此外,还对精浆的免疫抑制作用机理和意义进行了讨论。     

人IL-1β重组表达载体在肝癌细胞的表达及对其NK细胞杀伤敏感性的影响

目的：构建全长人IL-1β真核表达载体,转染H7402肝癌细胞,分析对其NK细胞杀伤敏感性的影响。方法：RT-PCR法扩增人IL-1β基因全长编码序列,经T-A克隆,构建pIRES2-EGFP-IL-1β重组表达载体,采用阳离子聚合物jetPEI的方法转染H7402肝癌细胞,G418筛选获得稳定表达的细胞克隆,RT-PCR分析IL-1β的表达水平,MTT方法分析转染前后NK细胞对肝癌细胞杀伤活性的变化。结果：从LPS处理的人外周PBMCs总RNA中扩增出IL-1β（大小约829 bp）,先构建pMD18-IL-1β克隆载体,DNA序列鉴定正确后,利用Pfu DNA聚合酶将IL-1β基因亚克隆到pIRES2-EGFP中,构建真核表达载体pIRES2-EGFP-IL-1β,经PCR、限制性酶谱分析（BamHⅠ和EcoRⅠ）和DNA序列测定正确后,将其转染H7402肝癌细胞,G418筛选获得稳定表达IL-1β的细胞,与转染空载体的细胞相比,该细胞对NK-92细胞杀伤的敏感性显著降低,效靶比10∶1时下降了约30%。结论：促炎性细胞因子IL-1β能够显著增强肝癌细胞对NK细胞杀伤的抵抗性,可能是导致肝癌细胞发生天然免疫逃逸的重要机制。     

Allograft rejection results from a failed attempt by the immune system to protect foreign tissue

The focus of our research is to understand the immune response to foreign tissue. We believe that adichotomy exists within the immune response to an allograft such that part of the response is dedicated to the protection of the graft. Nevertheless, in a dominantly graft-aggressive environment, rejection typically ensues. In this article, we describe models that have been set up to test directly the ability of potentially protective aspects of the immune response to prevent allograft rejection. We discussour data in the context of a growing body of exciting and often controversial literature.     

Increasing transplant mass results in long-term allograft survival and recovery from transplant vasculopathy

Late allograft rejection due to transplant vasculopathy continues to be a major clinical problem. Increasing the ratio of donor transplant size to recipient weight has been shown to reduce the incidence of late allograft failure. Using a murine pancreas transplant model we have tested the hypothesis that increasing the donor transplant size in a recipient can promote long-term allograft survival by promoting recovery from transplant vasculopathy. Recipients of an allograft that showed extensive vasculopathy were transplanted with a second donor transplant. The effect of the second allograft on the vasculopathy present in the first graft was measured. Transplanting a second allograft reversed all signs of ongoing rejection, including transplant vasculopathy, resulting in long-term survival of the first graft. Vasculopathy was only reversed if the first and second grafts were from the same mouse strain, suggesting an antigen-specific mechanism. However, the recovery of the first graft was not associated with antigen-specific peripheral tolerance.     

一个能诱生戊型肝炎病毒中和抗体的ORF2编码蛋白短片段

目的：比较戊型肝炎病毒（HEV）第4基因型ORF2编码蛋白片段pN472-C617（aa472～617）和pN477-C613（aa477～613）的免疫原性，找到能诱生HEV中和抗体的ORF2编码蛋白的更短片段。方法：表达和纯化pN472-C617和pN477-C613，分别免疫BALB/c小鼠，以间接ELISA检测免疫血清的抗体效价，并以基于PCR的体外中和试验检测免疫血清的中和活性。结果：pN472-C617和pN477-C613可在大肠杆菌高效可溶性表达，纯化后的重组蛋白能在小鼠体内诱导出高效价的抗体。基于PCR的体外中和试验显示pN472-C617免疫血清可有效中和HEV，阻断其在敏感细胞表面的吸附和细胞内复制；而两端仅比pN472-C617各短5个氨基酸的pN477-C613的免疫血清不具有中和HEV的活性。结论：重组蛋白pN472-C617具有良好的抗原性和诱生中和抗体的能力，是目前文献报道中含有HEV中和抗原表位的最短ORF2编码蛋白片段，可作为重组亚单位候选疫苗用于HEV疫苗的开发。     

戊型肝炎病毒Ⅰ、Ⅱ与Ⅲ、Ⅳ基因型B细胞抗原表位的异同

目的：制备戊型肝炎病毒(HEV)缅甸株和墨西哥株ORF2重组蛋白(p166Bur和p166Mex)的单克隆抗体(McAbs)，用于分析HEV不同基因型B细胞抗原表位的特点。方法：将免疫BALB/C小鼠脾细胞与SP2/0骨髓瘤细胞融合，获得分泌抗-p166Bur和抗-p166Mex McAbs的杂交瘤细胞株，然后采用ELISA和免疫印迹法测定McAbs与不同基因型HEV ORF2编码蛋白p166的免疫反应性。结果：获得4株杂交瘤细胞株，即分泌抗-p166Bur McAbs的2G2、2B1以及分泌抗-p166Mex McAbs的D8G10和E5E12，其中2B1分泌的McAb仅能与第Ⅰ、Ⅱ基因型编码的重组蛋白结合，而其余3株分泌的McAbs既能与Ⅰ、Ⅱ基因型HEV的p166重组蛋白发生反应，也能与Ⅲ、Ⅳ基因型的p166蛋白反应。结论：HEV第Ⅰ、Ⅱ基因型与Ⅲ、Ⅳ基因型ORF2编码蛋白既有共同又有不同的B细胞抗原表位。     

Induction of a TC1-mediated experimental autoimmune thyroiditis by deglycosylated porcine thyroglobulin

Contribution of cytotoxic T lymphocytes (CTL) to experimental autoimmune thyroiditis (EAT) was well defined (Speidel et al., Eur. J. Immunol. 1997, 27, 2391-2399, Ref. 7). The native porcine thyroglobulin (pTg) showed high sensitivity to endo-o-N-acetylglucosaminidase F (Endo F) and its molecular weights, corresponding to about 330 kDa as a monomer and 660 kDa as a dimer, were reduced to smaller molecular weight forms by Endo F and trifluoromethanesulfonic acid (TMSF). Deglycosylated porcine Tg (dgpTg) and native pTg were injected i.v. into CBA/J mice, without the aid of adjuvants. Both lymphocytic infiltrations of the thyroid glands and levels of Tg-specific CTL were similar to those found in conventional EAT induced by Tg and adjuvants. In contrast, proliferative responses in native pTg and dgpTg-injected mice could not be detected, and titers of antibodies to pTg and dgpTg were 20 times and 30 times lower than that of pTg and adjuvants, respectively. The EAT-inducer CTL belonged to the CD8+ cell subset and exerted their thyroiditogenic potential through release of IFN-gamma. It was concluded that dgpTg-induced EAT is mediated by type 1 cytotoxic T cells (Tcl). Also, results that EAT induction of the glycosylated pTg (gpTg) was much lower than that of dgpTg, suggested that the abberant and incomplete glycosylation of the thyroglobulin is responsible for the induction of autoimmune thyroiditis.