两株鼠抗人GL50单克隆抗体的制备及其生物学特性的初步研究

目的　研制鼠抗人GL5 0分子单克隆抗体并对其生物学特性进行初步研究。方法　以天然高表达人GL5 0分子的Daudi细胞为免疫原 ,人GL5 0 L92 9转基因细胞为目的单克隆抗体(McAb)的筛选细胞 ,采用B淋巴细胞杂交瘤技术 ,获得分泌特异性鼠抗人GL5 0分子McAb的杂交瘤细胞株 ;免疫荧光标记和流式细胞术分析McAb识别GL5 0的表达 ;Westernblot检测抗体对特异性细胞膜蛋白的识别 ;台盼蓝 (Trypanblue)染色细胞计数法和MTT法检测McAb对Daudi细胞体外生长的抑制作用 ;3 H TdR法检测抗体对GL5 0 L转基因细胞介导的活化T细胞体外增殖的效应。结果　成功制备 2株分泌特异性抗人GL5 0抗体的杂交瘤细胞株 12B11和 11C4 ;两者皆为IgG2a亚型 ;腹水效价皆在 1∶10 0 0以上 ;12B11、11C4特异性地识别GL5 0分子。 11C4McAb可以明显抑制Daudi细胞在体外的生长 ,并可抑制GL5 0 L转基因细胞介导的活化T淋巴细胞的体外增殖效应。结论　成功获得了 2株特异性鼠抗人GL5 0抗体 ,其中 11C4McAb具有诱导表达GL5 0分子的B淋巴瘤细胞Daudi的体外生长抑制作用 ;在T淋巴细胞体外增殖反应中发挥了重要的调节作用。     

Structural Reasons for Restricted Backbone Motion in Poly(n‐alkyl methacrylates): Degree of Polymerization,Tacticity and Side‐Chain Length

Summary: The complex dynamics of poly(n‐alkyl methacrylates) is studied by advanced ¹³C NMR spectroscopy as well as mechanical and dielectric relaxation. Extended backbone conformations are identified as the molecular units involved in structural relaxation. From the variation in the degree of polymerization and a comparison with the presence of stereoregular sequences in the sample, the length of the extended units is determined to involve about five, at most ten monomeric units. Syndiotactic and isotactic sequences behave similarly. These findings are indicative of locally structured polymer melts.

     

低分子肝素对缺血再灌注大鼠肾组织核因子-κB表达的影响

探讨低分子肝素对缺血再灌注大鼠肾组织核因子-κB（NF-κB）表达的影响。建立大鼠IRI模型，健康WistaI大鼠80只随机分为正常对照组、假手术组、模型未治疗组、LMWH治疗组，后两组又分别分为术后1、3、6、24h组。检测各组血清肌酐（Scr）水平及中性粒细胞（PMNs）细胞间黏附分子-1（ICAM-1）表达；通过光镜和免疫组织化学方法观察各组大鼠肾组织形态学及趋化因子NF-κB表达变化。结果表明：（1）肾缺血再灌注未治疗组造模后1h，Scr水平虽然没有明显变化，但ICAM-1、NF-κB表达增多，肾小管坏死积分值亦较假手术组明显增加（P〈0．01）；（2）缺血再灌注6h以后，两组Scr浓度明显增高（P〈0．01），但LMWH治疗组SCr、ICAM-1、NF-κB表达水平及肾小管坏死积分值均明显低于模型未治疗组（P〈0．05）；（3）肾组织中NF-κB表达与肾小管损伤积分值呈现良好的相关性（r=0．71，P〈0、01）；而NF-κB与ICAM-1间则呈现显著正相关（r=0．62，P〈0．05）。由此说明：（1）ICAM-1、NF-κB在肾缺血再灌注早期的瞬时表达，可能参与了炎症早期的白细胞迁移与浸润，与肾损伤的发生密切相关；（2）LMWH可通过减少ICAM-1及NF-κB的表达，阻抑炎症反应过程，减轻肾组织损伤。     

The Origin and Evolution of Human T-Cell Lymphotropic Virus Types I and II

Studies on human T-cell lymphotropic virus types I (HTLV-I) and II (HTLV-II) are briefly reviewed from the viewpoint of molecular evolution, with special reference to the evolutionary rate and evolutionary relationships among these viruses. In particular, it appears that, in contrast to the low level of variability of HTLV-I among different isolates, individual isolates form quasispecies structures. Elucidating the mechanisms connecting these two phenomena will be one of the future problems in the study of the molecular evolution of HTLV-I and HTLV-II.     

人Nanog基因的克隆及其在COS-7L细胞中的表达

目的 :克隆人Nanog基因 ,构建其真核表达载体 ,并观察其在哺乳动物细胞COS 7L中的表达。方法 :利用HE2 93细胞的人基因组DNA为模板 ,以LA PCR技术 ,扩增Nango的基因 ,定向克隆到带Flag标签的pCMV载体中 ,测序后 ,挑选序列正确的真核表达质粒pFlag Nanog转染COS 7L细胞。用抗Flag标签的抗体 ,进行Westernblot和间接免疫荧光染色法检测Nango蛋白的表达。结果 :从人基因组DNA中克隆到序列正确的Nanog全长编码序列。所构建的Nanog质粒在COS 7L细胞中获得高效表达。结论 :人Nanog基因的克隆、真核表达载体的构建及在COS 7L中的表达均获得成功 ,为进一步研究其功能 ,尤其是探讨其在神经干细胞中的作用奠定了基础。     

肺癌靶向多肽荧光分子探针的研制及其应用

目的:选择能与整合素α3受体结合的小分子多肽cNGQGEQc-L作为靶向载体，将羧基荧光素（FAM）与cNGQGEQc-L连接构建荧光分子探针，通过荧光成像探讨荧光多肽分子探针用于肺腺癌显像的可行性。方法:利用倒置荧光显微镜观察FAM-cNGQGEQc-L与肺腺癌A549细胞结合部位，流式细胞仪检测荧光多肽与A549细胞的竞争抑制实验，观察FAM-cNGQGEQc-L随浓度的增加与肺腺癌A549细胞结合能力的变化情况。通过小动物活体成像仪，观察荧光多肽在荷瘤裸鼠体内的生物分布特点。结果:倒置荧光显微镜显示荧光多肽cNGQGEQc-L能与A549细胞结合，结合部位在细胞膜和细胞质中。流式细胞仪测试结果证明荧光多肽与A549细胞的结合具有特异性和饱和性，当FAM-cNGQGEQc-L浓度为0.125 mmol/L时，荧光多肽与A549细胞的结合趋近饱和。荷瘤裸鼠活体成像显示移植瘤能够摄取荧光多肽，且荧光多肽通过泌尿系统和胆道系统排泄。结论:体外、体内荧光实验结果显示，荧光多肽分子探针FAM-cNGQGEQc-L可与肺腺癌A549细胞、肺癌移植瘤结合，能够特异性靶向肺腺癌。     

Comparison of DNA- and RNA-based methods for detection of truncating BRCA1 mutations

A number of methods are used for mutational analysis of BRCA1, a large multi-exon gene. A comparison was made of five methods to detect mutations generating premature stop codons that are predicted to result in synthesis of a truncated protein in BRCA1. These included four DNA-based methods: two-dimensional gene scanning (TDGS), denaturing high performance liquid chromatography (DHPLC), enzymatic mutation detection (EMD), and single strand conformation polymorphism analysis (SSCP) and an RNA/DNA-based protein truncation test (PTT) with and without complementary 5' sequencing. DNA and RNA samples isolated from 21 coded lymphoblastoid cell line samples were tested. These specimens had previously been analyzed by direct automated DNA sequencing, considered to be the optimum method for mutation detection. The set of 21 cell lines included 14 samples with 13 unique frameshift or nonsense mutations, three samples with two unique splice site mutations, and four samples without deleterious mutations. The present study focused on the detection of protein-truncating mutations, those that have been reported most often to be disease-causing alterations that segregate with cancer in families. PTT with complementary 5' sequencing correctly identified all 15 deleterious mutations. Not surprisingly, the DNA-based techniques did not detect a deletion of exon 22. EMD and DHPLC identified all of the mutations with the exception of the exon 22 deletion. Two mutations were initially missed by TDGS, but could be detected after slight changes in the test design, and five truncating mutations were missed by SSCP. It will continue to be important to use complementary methods for mutational analysis.     

Subtyping of MRSA isolates belonging to a widely disseminated clonal group by polymorphism of the dru sequences in mec-associated DNA

During the past 7 years the "Berlin epidemic MRSA" has spread throughout whole Germany. SmaI macrorestriction patterns of this clonal group are rather stable as are the length polymorphisms at the 3' end of the coagulase gene and the x-region of spa. However, the dru region (direct repeat units) of mec-associated DNA exhibits a length polymorphism due to deletion of one or more direct repeat units. Five different subclones could be discriminated by dru region length polymorphism. Location of deletions and of a few point mutations allow a delineation of these subclones.