特异性DNA倍增技术检测t-PA cDNA基因在表达细胞中的稳定性

利用特异性DNA倍增技术(polymerase chain Reaction,PCR)检测t-PA cDNA基因在表达细胞基因组中的稳定性,并对所得的PCR反应产物进行了限制性内切酶片段、分子杂交和核苷酸顺序分析等方面的研究,证实了t-PA cDNA基因已插入到表达细胞染色体中。这种方法快速、简便、灵敏度和特异性高,是检测基因工程表达细胞中cDNA基因稳定整合状况的好方法。     

A newly recognized point mutation in the cytochrome b558 heavy chain gene replacing alanine57 by glutamic acid,in a patient with cytochrome b positive X-linked chronic granulomatous disease

Molecular genetic analysis was performed in a patient with cytochrome b positive X-linked chronic granulomatous disease. A previous Southern blot study, using a cytochrome b heavy chain cDNA as probe, revealed a Pst I restriction fragment pattern for the cytochrome b heavy chain gene (CYBB) different to that of normal individuals. Since restriction length polymorphism with Pst I has never been observed in control individuals and no abnormal restriction fragment patterns in the patient's CYBB was detected with seven other enzymes used, we focussed on the single Pst I site in the CYBB cDNA as being the only mutation site responsible for his disease. A fragment of the patient's cDNA which included the Pst I site was amplified by reverse polymerase chain reaction, and loss of the Pst I site in the fragment was confirmed by incubation with Pst I. Subsequent sequence analysis of the fragment revealed a point mutation in the Pst I site (cytosine to adenine), substituting glutamic acid for alanine at position 57.     

SRY基因诊断在临床中的应用

应用聚合酶链式反应（ＰＣＲ）扩增技术，对１０例染色体核型为４６，ＸＹ和１例为４６，ＸＸ／４６，ＸＹ的性反转、睾丸女性化、两性畸形及男性生殖器发育不良的患者进行了性别决定区（ＳＲＹ）基因检测。结果表明９例４６，ＸＹ和１例４６，ＸＸ／４６，ＸＹ患者的ＳＲＹ基因存在，１例４６，ＸＹ女性患者的ＳＲＹ基因缺失。该结果表明能够用分子生物学技术对性反转、性发育异常的病因进行分析     

膀胱肿瘤组织中端粒酶催化亚基和c-myc的表达

目的 研究膀胱肿瘤组织中端粒酶催化亚基(hTERT)和c-myc间的表达及关系。方法 采用逆转录-聚合酶链反应(RT-PCR)法对27例膀胱肿瘤组织、16例癌旁组织和16例正常膀胱粘膜同时测定hTERT和c-myc表达,分析两指标在3种组织的表达差异和相关性。结果 TCC组织hTERT和c-myc的表达阳性率分别为100.0％(27/27)和66.7％(18/27);癌旁组织两指标的阳性率均为 37.5％,而正常膀胱粘膜分别为 0和 25.0％;hTERT和c-myc两指标在膀胱肿瘤组织中的阳性表达有相关性(P<0.01)。结论 hTERT较c-myc作为TCC的诊断指标更灵敏和特异;两指标在TCC中的阳性表达具有相关性。     

血浆巨细胞病毒多聚酶链反应检测用于指导干预性治疗

目的：分析用血浆巨细胞病毒（cytomegalovirus,CMV)多聚酶链反应（plymerase chain reaction,PCR)检测结果指导抗CMV干预性治疗的临床意义。方法：1999年8月至2001年7月行异基因造血干细胞移植（hematopoietic stem cell transplantation,HSCT)的所有患者自预处理开始，常规用PCR法检测血浆的CMV－DNA（采用华美公司生产的巨细胞病毒4℃ PCR检测试剂盒），每周1次。其中尚无CMV病的临床表现而检测到血浆CMV阳性的患者89例。随机选取52例阳性患者给予干预性治疗。将上述89例患者分为3组（分别为停止治疗时血浆CMV－PCR转阴组、停止治疗时未转阴组、血浆CMV阳性未治疗组）比较各组CMV病的发生率。CMV病的发生率采用Kaplan-Meier曲线表示，曲线间的比较用Log-Rank（曲线无交叉）或Breslow（曲线交叉）检验，某时点率的比较采用RXC列联表或χ^2检验。结果：100d内CMV病的发生率，在治疗后血浆CMV－PCR由阳性转为阴性组为10．26％，治疗结束时血浆CMV－PCR仍为阳性组为66.67%，血浆CMV－PCR阳性未治疗组为36．24％（P＝0.0000)。上述3组中任两组移植后100d CMV病的发生率差异均有显著性。移植后1年时上述3例CMV病累积发生率分别为30.65%、75.00%、42.95%(P=0.0009)，治疗未转阴组与治疗转阴组和阳性未治疗组相比，CMV病的发生率明显升高。结论：血浆CMV－PCR检测结果用来指导干预性治疗有一定临床意义。干预性治疗后血浆CMV－DNA仍未转阴者，应考虑换药或联合用药治疗。     

聚合酶链反应检测淋球菌的临床应用

应用ＰＣＲ法对１１３例临床标本中淋球菌菌体内所特有的４．２ｋｂ隐蔽性质粒上的ｃｐｐＢ基因进行了检测。与直接涂片法相比，ＰＣＲ法的敏感性和特异性分别达１００％和８７．５％。     

白色念珠菌感染的分子生物学诊断研究进展

综述了白色念珠菌感染的分子生物学诊断研究进展，包括核型分析，限制性片段长度多态性分析，特异的ＤＮＡ探针及ＰＣＲ等方法。     

Hormone receptors in vestibular schwannomas

Summary The possibility that steroid hormones play a role in vestibular schwannoma proliferation has been suggested by a number of investigators. There is conflicting information about the presence of steroid hormone receptors in these tumors. The aim of this study was to examine the expression of androgen, progesterone, glucocorticoid and estrogen receptor messenger ribonucleic acid levels (mRNA) in twenty-one vestibular schwannomas by either Northern blot analysis or the polymerase chain reaction (PCR).Glucocorticoid receptor mRNA was expressed in all twentyone tumors examined. Only two male specimens were positive for androgen receptor mRNA expression by PCR-Southern blot analysis. Thirty-three percent of the schwannomas (7/21) showed a strong band for progesterone receptor mRNA by PCR-Southern blot analysis; there were an equal number of males and females in this group. Estrogen receptor mRNA levels were undetectable in all tumors examined by PCR-Southern blot analysis. These studies suggest that the pattern of steroid receptor expression is different in schwannomas than in meningiomas. Individual vestibular schwannomas need to be examined for their steroid receptor mRNA expression mRNA expression to know whether they will be responsive.