等位基因特异PCR技术检测结核分支杆菌rpoB基因突变研究

目的 建立并评价等位特异多聚酶链反应检测结核分支杆菌耐利福平基因rpoB突变的方法。方法 设计与rpoB基因突变后的碱基配对的引物用于扩增突变基因，建立AS－PCR检测rpoB基因突变的方法，并对58株结核菌进行了检测。结果 AS－PCR检测结核菌耐利福平相关基因rpoB的敏感性为77.3%，特异性达91.7%。AS－PCR检测rpoB基因，有1628A→T、1657C→T，G和1673C→T突变分别占耐利福平结核菌株的18.2%，22.7%和36.4%。检测rpoB突变与MIC测定RFP耐药率和PCR－SSCP检测的总符合率分别为86.2%和74.1%。检测试验可在3－4h内完成。结论 AS－PCR方法是检测结核菌耐利福平基因突变的敏感和快速方法，可在临床实验室使用并为临床医师提供治疗依据。     

Characterization of an immunologic polymorphism (D79H) in the heavy chain of factor V.

BACKGROUND: During the study of a family with hereditary factor (F)V deficiency (FV Amersfoort, 1102 A > T in exon 7) we identified an individual with 5% FV heavy chain antigen (FV(HC)) and 50% FV light chain antigen (FV(LC)). Further testing revealed that apart from the FV Amersfoort allele a second variant FV allele was segregating in this family, which encodes for a FV molecule with a reduced affinity for mAb V-23 used in the FV heavy chain ELISA (ELISA(HC)). OBJECTIVE: Identification and characterization of the molecular basis responsible for the reduced affinity of the variant FV for mAb V-23. METHODS: Family members of the proband were screened for mutations in the exons coding for the heavy chain of FV, after which the recombinant variant FV could be generated and characterized. Next, the cases and controls of the Leiden Thrombophilia Study (LETS) were genotyped for carriership of the variant FV. RESULTS: In the variant FV allele a polymorphism in exon 3 (409G > C) was identified, which predicts the replacement of aspartic acid 79 by histidin (D79H). Introduction of this mutation in recombinant FV confirmed that it reduces the affinity for binding to mAb V-23. The substitution has no effect on FV(a) stability and Xa-cofactor activity. In Caucasians the frequency of the FV-79H allele is approximately 5%. Analysis of the LETS revealed that the FV-79H allele is not associated with FV levels (FV(LC)), activated protein C sensitivity (using an activated partial thromboplastin time-based test) or risk of venous thrombosis (OR 1.07, CI 95: 0.7-1.7). CONCLUSION: The D79H substitution in FV should be considered as a neutral polymorphism. The monoclonal antibody V-23, which has a strongly reduced affinity for FV-79H, is not suitable for application in diagnostic tests.     

TNF-β+252单核苷酸多态性与胃癌恶液质的关系

目的探讨肿瘤坏死因子-β（TNF-β）＋252基因单核苷酸多态性与胃癌病人癌性恶液质的关系.方法 105例营养不良胃癌病人,按照近6个月体质量的减轻率分成3组：A组,0～5%;B组,6%～10%;C组,〉10%.用PCR结合限制性内切酶检测胃癌病人及110例正常志愿者TNF-β＋252单核苷酸多态性.结果 TNF-β＋252A（TNFB2）出现的频率在胃癌组和对照组差异无显著性（P〉0.05）.在胃癌病人中,TNFB2出现的频率在A、B、C各组差异亦无显著性（P〉0.05）;恶液质病人TNFB2出现的频率与对照组比较差异无显著性（P〉0.05）.结论 TNF-β＋252基因单核苷酸多态性与胃癌恶液质的发生无相关性.     

Effect of cystathionine beta-synthase variant 844ins68bp and methylenetetrahydrofolate reductase A1298C polymorphisms in xenografts on 5-FU efficacy and doubling time

The association of MTHFR and CBS variants with the doubling time and responsiveness to several chemodrugs was analyzed in 26 human cancer xenografts. The tumors homozygous for the absence of insertion (NN) for the CBS 844ins68bp were more chemosensitive than those with insertion (NI) to TS-1 (P=0.0048), suggesting a potential effect of this variant on fluoropyrimidine efficacy. Furthermore, the doubling time of tumors with a variant C allele (AC or CC) in MTHFR-A1298C was significantly longer than that of tumors with a normal allele (AA) (P=0.0008). Twenty-nine cellular proliferation-related genes were associated with MTHFR-A1298C genotyping and with the doubling time.     

银染单链构象多态性检测冠心病载脂蛋白E基因型

目的 ①建立一种简便、准确、实用的人栽脂蛋白E(apoE)基因型的检测方法；②研究冠心病(CHD)患者栽脂蛋白E基因多态性。方法 应用聚合酶链反应(PCR)特异性扩增apoE基因含编码112位和158位氨基酸的基因序列，用SS—SSCP技术进行apoE基因型分析。结果 运用SS—SSCP法检测了47名冠心痛患者apoE基因型，发现ε4／2、ε3／2、ε3／3、ε4／3、ε4／4基因频率分别为4．26％，14．89％，63．83％，12．76％，4．26％，并且发现ε2、ε3、ε4等位基因频率分别是9．57％，77．66％，12．77％。结论 ①该方法简单、快速、准确，对人体无害，适合于一般实验室开展；②ε4等位基因是CHD的易患因子之一，而ε3等位基因则具有保护作用。     

No association of C-1019G promoter polymorphism of 5-HT1A receptor gene with migraine

It is well known that migraine has a strong genetic component, although the type and number of genes involved remains unclear. There is evidence to suggest that serotonin-related genes may be involved in the pathogenesis of migraine. To investigate whether the 5-HT1A receptor gene contributes to the risk of migraine we performed an association study of C-1019G promoter polymorphism of the gene in 102 migraineurs and 93 controls. Subjects were of Han Chinese origin. No significant differences in allele (P=0.82) or genotype frequencies (P=0.71) were seen in migraineurs compared with the controls. When migraine with aura, without aura, with family history, without family history were analyzed separately, the frequencies did not vary significantly. Our results suggest that C-1019G in 5-HT1A is not a major genetic risk factor for migraine.     

情感障碍高发家系遗传学初步研究

目的探测儿茶酚氧位甲基转移酶(COMT)基因、载脂蛋白E(Apo-E)基因及五羟色胺受体2A(5-HT2a)基因多态性与情感障碍之关系,搜寻中国汉族人情感障碍易患性基因.方法应用聚合酶链反应(PCR)和限制性片段长度多态性(RFLP)方法对5个情感障碍高发家系进行初步研究.结果用改进的传递/不平衡(TDT)检测结果表明,在5个情感障碍高发家系中,COMT基因与情感障碍相关联(P＜0.05),而Apo-E基因和5-HT2a基因不与情感障碍关联(P＞0.05).结论在我们研究的家系中,22号染色体和长臂(22q11.2)可能存在情感障碍易患性基因.     

β2-ADRENERGIC RECEPTOR GENE POLYMORPHISM IN CHINESE NORTHERN ASTHMATICS

THEβ2-adrenergicreceptor(β2-AR)ishighlyexpre-ssedonairwaysmoothmusclecellsinlung,anddefectsinβ2-ARsignalpathwaywereinvolvedinthepathogenesisofasthma.1 Humanβ2-ARgeneisanintr-onlessgenewithacodingblockconsistingof1239nucleo-tidesonchromosome5q31-32,genome-widesearchforas-thmasusceptibilitylocishowedthatmarkersonthisregionhavebeenlinkedtoasthma-associatedphenotypesinvariousethnicpopulations.2 Reihsausetal3 firstdescribedninecod-ingregionpolymorphisms,particularly,thethreecommonaminoacidsu…     

深部脑白质缺血影像表现与MTHFR基因多态性关系的探讨

目的：探讨MTHFR的纯合突变TT型基因是否为诱发皮层下深部脑白质缺血的危险因子，并证实皮层下深部脑白质缺血影像表现与MTHFR基因C／T多态性的关系。资料与方法：选择影像表现符合皮层下深部脑白质缺血诊断标准者30例，对照组30例为影像表现正常者，运用多聚酶链反应－限制性内切酶片段长度多态性技术（PCR－RFLP）检测两组MTHFR基因多态性。结果：采用χ^2检验，得出MTHFR基因纯合突变TT型在病变组与对照组比较差异有显著性（χ^2=5.0794,P＜0．05），病变组TT型较对照组显著升高，说明MTHFR的纯合突变TT型可能是诱发深部脑白质缺血的危险因素。运用成组设计两样本比较的秩和检验，得出TT型和非TT型患者在影像表现的分级程度上有差别，携带TT型基因者影像表现分级重。结论：MTHFR纯合突变TT型基因是深部脑白质缺血发病的危险因子，且TT型基因与深部脑白质缺血的易感性和影像表现呈明显正相关。