Copy number of the 16S rRNA gene in Coxiella burnetii

Coxiella burnetii is an obligate intracellular bacterium with a doubling time of 5–7 hours. Chromosomal DNA from C. burnetii was digested with various restriction enzymes previously determined to not cut within the genomic 16S rRNA gene, or with a combination of these noncutting enzymes in conjunction with AflIII, a restriction enzyme that cuts twice within the 16S rRNA gene. Restriction fragments were resolved electrophoretically and probed with a radiolabeled DNA fragment containing the 3 AflIII portion of the C. burnetii 16S rRNA gene. Only a single DNA fragment in these digests hybridized to the probe, indicating that there is a single genomic copy of the 16S rRNA gene in C. burnetii and thus only a single copy of the rRNA operon.     

P^16基因蛋白在子宫颈鳞癌组织中的表达

应用免疫组织化学方法对58例子宫颈鳞状上皮细胞癌及5例宫颈上皮内瘤样病变标本的P^16基因表达进行研究,取8例正常子宫颈组织作对照,结果显示：P16基因的阳性表达率在宫颈鳞癌,宫颈上此内瘤样病谱及正常宫颈组织中分别为43．1％,40％,12．5％,肿瘤病理分级越低,临床分期越晚,阳性表达率越低,差异有显著性（P＜0．05）,提示：P16基因的异常表达在子宫颈鳞癌的发生,发展过程中起重要作用。     

原位PCR和免疫组化检测垂体腺癌P16基因

目的研究人垂体腺瘤P16基因的改变,同时探索原位PCR技术的适宜条件和结果确认,以及用于基因缺失检测的可行性。方法原位PCR和免疫组化技术。结界绝大部分间质细胞为P16蛋白免疫组化阴性,而一部分垂体肿瘤细胞呈P16阳性;针对P16基因的原位PCR信号则可见于垂体肿瘤细胞和间质细胞等各种细胞,即P16组化阴性的细胞同样表明有P16基因存在。结论原位PCR可以是P16基因研究的一种有效手段,提示垂体腺癌的P16基因改变形式可能主要是表达过度而不是基因缺失。     

Molecular cytogenetic characterization of 16p11.2 microdeletions with diverse prenatal phenotypes: Four cases report and literature review

ObjectiveChromosome 16p11.2 deletions have been recognized as a genetic disorder with well-described postnatal phenotypes. However, the prenatal manifestations are atypical for lacking of enough evidence.Case reportFour pregnant women underwent amniocentesis for cytogenetic analysis and chromosomal microarray analysis (CMA) because of various indications for prenatal diagnosis: prenatal ultrasound abnormalities (cases 1, 2 and 4) and the childbearing history of cerebral palsy child (case 3). No overlapping phenotypes were observed in cases 1, 2 and 4, which might indicate phenotypic diversities in prenatal phenotypes for 16p11.2 microdeletion. All four fetuses showed normal karyotypic results while CMA identified 0.303–0.916 Mb microdeletions of 16p11.2, encompassing BP2–BP3 and BP4–BP5 regions separately. According to the parental CMA verification, case 1 carried a maternal inherited duplication in the region of Xp22.33 and a de novo deletion in the region of Xp21.1. All parents opted for the termination of pregnancies based upon genetic counselling.ConclusionOur findings enriched the intrauterine phenotypic features of 16p11.2 microdeletions, which would be beneficial for genetic counselling in clinic. In addition, preimplantation genetic testing was recognized as a first-tier approach for such carriers if they intended to conceive again.     

胰腺癌 P16、 P53及 PCNA 的表达及其临床意义

目的：研究胰腺癌中 Ｐ１６和 Ｐ５３基因产物的表达及其临床意义。方法：应用免疫组化 Ｌ Ｓ Ａ Ｂ法研究２８例胰腺癌组织中 Ｐ１６蛋白和 Ｐ５３蛋白的表达情况,并进行增殖细胞核抗原（ Ｐ Ｃ Ｎ Ａ）检测,计算细胞增殖指数（ Ｐｒｏｌｉｆｅｒａｔｉｏｎ ｉｎｄｅｘ, Ｐ Ｉ）。结果： Ｐ１６蛋白低表达和 Ｐ５３蛋白过表达均有促进胰腺癌细胞增殖的作用。 Ｐ１６蛋白表达与淋巴结转移无关; Ｐ５３蛋白高表达者具有较高的淋巴结转移率,预后较差。 Ｐ１６蛋白低表达与 Ｐ５３蛋白高表达共存者,其恶性度最高,预后最差。结论：联合检测 Ｐ１６和 Ｐ５３蛋白表达情况,更能充分反映胰腺癌的生物学行为,对胰腺癌患者预后判断及临床治疗有指导意义。     

p16在肝细胞癌组织内变异的研究

应用分子杂交及免疫组化方法检测５６例ＨＣＣ组织内的抑癌基因ｐ１６。结果显示,ＨＣＣ标本中ｐ１６蛋白在癌细胞内表达的阳性率为３７５％（２１／５６）,而ｐ１６ＤＮＡ斑点杂交的阳性率为５５３６％（３１／５６）。Ｓｏｕｔｈｅｒｎ转膜杂交证实,１２５％（７／５６）ＨＣＣ标本存在ｐ１６的甲基化变异,４４６４％（２５／５６）ｐ１６基因缺失。提示ＨＣＣ发生、发展过程中存在ｐ１６基因的缺失和甲基化变异     

P^16蛋白,增殖细胞核抗原在肾癌的表达及与预后的关系

目的　探讨多肿瘤抑制基因Ｐ１６／ＭＴＳ１蛋白在肾细胞癌（ＲＣＣ）的表达及与临床病理指标、预后的关系。方法　采用免疫组化方法对Ｐ１６蛋白和增殖细胞核抗原（ＰＣＮＡ）在５６例ＲＣＣ的表达进行病理观察。结果　Ｐ１６蛋白在ＲＣＣ的阳性率为６０．７％（３４／５６）,各组织学分级的阳性率差异有显著性（Ｐ＜０．０１）,其阳性组和阴性组的５年生存率差异无显著性。ＰＣＮＡ标记指数（ＰＣＮＡＬＩ）在１％～８５％,平均为１９．７％,在不同组织学分级及临床分期中差异有显著性（Ｐ＜０．０１）。ＰＣＮＡ高表达组和ＰＣＮＡ低表达组的５年生存率差异有显著性（Ｐ＜０．０５）。Ｐ１６蛋白的表达与ＰＣＮＡ无一致性（Ｐ＜０．０５）。结论　ＰＣＮＡＬＩ是反映ＲＣＣ组织分化程度及预后的良好指标,Ｐ１６蛋白的胞浆型表达对肾癌临床分期及预后无明显影响。     

PCR和分离培养检测细胞培养支原体污染的比较

目的：检测细胞培养中支原体的污染,建立支原体通用的ＰＣＲ方法。方法：根据已出版的序列设计并合成一对支原体（柔膜体纲）１６ＳｒＲＮＡ基因组特异引物。对实验室所存的１２种支原体、大肠杆菌、变形杆菌及无支原体污染的组织培养细胞进行了ＰＣＲ扩增。以ＰＣＲ与分离培养比较检测了３３份细胞培养标本。结果：１２种支原体均出现了约６２０ｂｐ左右的特异性扩增带,敏感性为１００～１０００个支原体细胞,且常见的６种细胞培养污染支原体的扩增片段均能被ＨｉｎｄⅢ切成２８０与３４０ｂｐ左右的２条带。理论上推测这对引物可扩增所有支原体１６ＳｒＤＮＡ。但对大肠杆菌、变形杆菌及无支原体污染的组织培养细胞等未见有扩增带出现。在对３３份细胞培养标本的检测中,除ＰＣＲ和分离培养同时检出２份阳性外,前方法还另检出阳性３份。５份ＰＣＲ扩增物均被ＨｉｎｄⅢ切出２条带。结论：ＰＣＲ较分离培养敏感性高,可提高细胞培养污染支原体的检出率,防止出现假阴性结果;如做好质量控制,对于一般实验室检测细胞培养支原体污染,ＰＣＲ扩增较分离培养具有更大的应用意义     

聚合酶链反应检测细菌16S rRNA基因

根据细菌１６ＳｒＲＮＡ基因的高度保守性,设计合成所有细菌、革兰氏阳性细菌及革兰氏阴性细菌的共同引物,采用聚合酶链反应检测已知细菌１３株,三对引物分别扩增的阳性率为１００％,倍比稀释法能检出细菌的最低浓度为４ＣＦＵ·ｍｌ－１,同时检测临床样本４０份,阳性率为６７５％（２７／４０）,同期细菌培养阳性率为４５％（１８／４０）,二者比较差异有显著性（Ｐ＜０．０５）。结果提示聚合酶链反应检测细菌１６ＳｒＲＮＡ基因具有高度的特异性和敏感性。     

Ginkgo biloba extract EGb761 reduces the development of amphetamine-induced behavioral sensitization: effects on hippocampal type II corticosteroid receptors

Pretreatment of rats with the extract of Ginkgo biloba termed EGb761 reduced the behavioral sensitization induced by successive -amphetamine administrations (0.5 mg/kg) as estimated by increasing values of locomotor activity. EGb761 pretreatment also prevented the reduced density of [³H]dexamethasone binding sites in the dentate gyrus and the CA1 hippocampal regions of -amphetamine treated animals. These observations suggest that EGb761, by reducing glucocorticoid levels, could modulate the activity of the neuronal systems involved in the expression of the behavioral sensitization.