抗-HCV与HCV-RNA在丙型肝炎诊断中的观察

目的 探讨早期检测抗-HCV和HCV-RNA对诊断丙型肝炎的价值。方法 通过用酶联免疫吸附法(ELISA)和逆转录PCR法，对198例丙型肝炎患者检测其抗-HCV和HCV-RNA。结果 抗-HCV总阳性率为84％，抗-HCV、HCV-RNA同时阳性为58％，抗-HCV单项阳性为26％，抗-HCV阴性而HCV-RNA阳性为16％。结论 HCV-RNA对早期HCV感染的诊断以及抗-HCV阴性的慢性丙肝的诊断有重要意义。对怀疑HCV感染者应同时检测抗-HCV和HCV-RNA，才能对不同时期的HCV感婆作出准确及时的诊断。     

多聚酶链反应检测细菌DNA对大鼠空、回肠吻合口瘘的早期诊断价值

目的:探讨PCR检测大鼠外周血及腹水中细菌DNA对空肠-空肠、回肠-回肠吻合口瘘的早期诊断价值。方法:健康Wistar雌性大鼠50只，随机分成5组，每组10只：A组为假手术组;B组为空肠-空肠吻合组;C组为空肠吻合口瘘组;D组为回肠-回肠吻合组;E组为回肠吻合口瘘组。采集手术前后外周血及术后腹水，抽提DNA, 比较lacZ基因和16SrRNA基因的PCR阳性率，并观察各组的病理学情况。结果:（1）C，E组术后外周血lacZ基因PCR阳性率与B，D组无显著性差异（P>0.05）;C，E组术后外周血16SrRNA基因PCR阳性率显著高于B，D组（P<0.05）。（2）C，E组腹水lacZ基因和16SrRNA基因PCR阳性率均显著高于B，D组（P<0.05）。（3）C，E组腹水lacZ基因阳性率显著高于外周血（P<0.05）;C，E组腹水16SrRNA基因阳性率与外周血无显著性差异（P>0.05）。结论:（1）PCR检测术后外周血16SrRNA基因对空、回肠吻合口瘘的早期诊断有一定意义;（2）检测术后腹水lacZ基因和16SrRNA基因对空肠-空肠、回肠-回肠吻合口瘘的早期诊断也有一定意义。     

Tau isoform expression in frontotemporal dementia without tau deposition

In many cases of sporadic frontotemporal dementia (FTD) and in FTD caused by tau mutations (FTDP-17) there is disruption of the normal splicing of tau leading to the aberrant expression of tau isoforms and neurodegeneration. This suggests a central role for tau in the pathogenesis of FTD. However, more than half the cases of sporadic FTD show no tau deposition. We question whether altered expression is also involved in the pathogenesis of tau-negative FTD. Real-time polymerase chain reaction was used to investigate tau isoform expression in tau-negative FTD and age-matched controls. There were no differences in total tau mRNA or 4R versus 3R isoform expression. Our study suggests that perturbed tau mRNA expression is unlikely to be involved in the pathogenesis of tau-negative FTD.     

高转移小鼠肺癌株细胞导入人基因组DNA后的转移表型抑制

目的 探讨从正常人细胞基因组ＤＮＡ中寻找、分离并鉴定肿瘤转移抑制基因或相应ＤＮＡ序列的新途径。方法 采用体内转移灶体外再培养再硬琼脂集落克隆化筛选，获体内９０％以上高转移率小鼠肺腺癌ＬＭ２细胞株；使用磷酸钙共沉淀ＤＮＡ转染技术，将正常细胞人基因组ＤＮＡ随机片段，导入高转移小鼠肺癌细胞株ＬＭ２后，使用有限稀释法克隆化其中形态扁平的回复突变株。为证实细胞确实含有外源人ＤＮＡ序列，设计人特异性Ａｌｕ引物     

聚合酶链反应检测实验动物弓形虫核酸的研究

建立弓形虫动物模型，常规方法提取肝、脾、肾、肺等组织DNA，应用聚合酶链反应（PCR）扩增，产物经电泳检测显示199bp的弓形虫特异带谱。并以γ－32p标记克隆的弓形虫特异DNA片段为探针，对扩增产物行Southern印迹分析，结果上述4种标本均出现阳性杂交带，进一步证实扩增条带是弓形虫特异DNA顺序。同时用酶标法检测显示鼠血清弓形虫抗体IgG；阳性。组织病理学检查结果，肝组织损伤较严重，肝细胞肿大，肝窦消失，脾、肾、肺组织可见轻微的病理改变。另外本文介绍一种简单PCR方法[1]，取鼠尾静脉血2μl直接进行扩增，结果与酚-氯仿法提取的DNA扩增结果一致。     

Rapid determination of trisomy 18 parental origin using fluorescent PCR and small tandem repeat markers: case reports

Trisomy 18 is the second most common genetic defect after trisomy 21, almost 90% of which are due to additional chromosome from the mother. The parental origin of the additional chromosome can, if required, be determined by two methods: karyotyping, which takes several weeks; or, more recently, by polymerase chain reaction (PCR) which is often problematic. Fluorescent PCR of small tandem repeats (STRs) can determine the parental origin in the majority of cases within 5 h. Although the incidence of paternal origin is known for both trisomy 21 and trisomy 18, this technique can rapidly determine the parental origin in cases where there is insufficient samples to perform conventional tests. Determining parental origin by these methods may also have clinical significance in the diagnosis of chromosomal translocations or in the diagnosis of genetic disease using linkage analysis.     

P53基因突变与宫颈癌关系的研究

目的：通过对宫颈癌Ｐ５３基因７－８外显子突变的研究，探讨该基因的突变与宫颈癌的发生、发展之间的关系。方法：本文运用聚合酶链式反应（ＰＣＲ）方法，对宫颈癌组织Ｐ５３的７－８外显子是突变进行了试验，并与非肿瘤的慢性宫颈炎（宫颈糜烂、宫颈息肉）组织作了对照。结果：１０例宫颈癌标本中有７例出现了Ｐ５３７－８外显子的突变，阳性率高；而８例作为对照的宫颈炎标本仅有１例出现可疑的阳性结果。结果：试验结果说明，宫     

PCR检测结核分枝杆菌DNA中不同细菌裂解方法结果观察

目的：寻找适合于临床ＰＣＲ检测结核杆菌ＤＮＡ简单、快速、有效、经济的细菌裂解方法。方法：采用１１种细菌裂解剂对相同数量的结核分枝杆菌进行裂解，裂解上清液直接用于ＰＣＲ扩增，结果：１％ＴｒｉｔｏｎＸ－１００，１％ＮＰ４０，１％Ｔｅｗｅｅｎ２０、和１％ＯＰ四种裂解剂的裂解液可直接扩增出结核分枝杆菌ＤＮＡ；ＳＤＳ，ＮａＯＨ，十二烷基肌酸钠等裂解剂的裂解液直接用于ＰＣＲ扩增均为阴性。结论：１％的Ｔｒｉｔｏｎｘ－１００，ＮＰ４０、Ｔｅｗｅｅｎ２０和乳化剂ＯＰ裂解细菌效果好，又不抑制ＰＣＲ反应，适合于作为临床ＰＣＲ检测结核杆菌的裂解剂。     

聚合酶链反应在鼠疫菌检测中的应用 研究

本文采用聚合酶链反应（ＰＣＲ）技术，通过扩增鼠疫菌９．５ｋｂ质粒ｐｌａ基础上一个４７８ｂｌ片段，用于鼠疫菌检测，被试的４５株鼠疫菌扩增产物经琼脂糖凝胶电泳分析均呈现单一ＤＮＡ带，其分子量大小与预期结果符合。而假结核菌和一株缺６ＭＤ质粒鼠疫菌未见扩增带，洽部实验可在４ｈ内完成。本法具有快速、特异、敏感等优点，可用于不同生态型鼠疫菌的快速诊断和流行病学研究．     

Using the polymerase chain reaction to maintain DNA probe inventories in clinical and diagnostic laboratories

Clinical and diagnostic DNA laboratories must maintain a large inventory of DNA probes for use in hybridization studies. The preparation of plasmid DNA and isolation of DNA fragments for use as probes in both expensive and time consuming. We present here a rapid and relatively inexpensive method of producing large amounts of DNA fragments from stocks, using the polymerase chain reaction (PCR). Our experience over the past year using this technique has been very positive and we believe many laboratories could benefit by employing such a labor-saving approach to maintaining DNA probes. The technique uses the bacteriophage M13 DNA sequencing primers to amplify cloned inserts contained in commonly used plasmid vectors. As examples, we illustrate the use of DNA produced in this manner as probes for linkage analysis of the fragile X syndrome and for detection of deletions in the Duchenne muscular dystrophy gene. We have also found that at least two probes can be amplified in the same PCR reaction, allowing the detection of two different restriction fragment length polymorphisms (RFLP) simultaneously. It should be possible for laboratories to devise strategies particular to their individual needs using more than one DNA probe produced in the same PCR reaction to detect RFLP's. Such strategies would need only to consider that the predicted alleles of the multiple polymorphisms do not migrate to the same position during electrophoresis. Stocks of single or multiple probes produced by the PCR could then be maintained for more rapid Southern analyses.