人类白细胞抗原B27亚型基因与急性前葡萄膜炎的相关性研究

目的 探讨人类白细胞抗原B27亚型基因与急性前葡萄膜炎(acute anterior uveitis,AAU)易感性的关系。 方法 对49例临床确诊的AAU患者,通过聚合酶链反应(polymerase chain reaction, PCR)特异性扩增技术检测B27;以B27阳性者的DNA为模板对其人类白细胞抗原HLA-B的第二、三外显子片段扩增。采用DNA测序技术对扩增产物做基因序列分析,经计算机处理获得受检者HLA-B27亚型的信息。 结果 受检者中29例为B27阳性,占59.39%,其中仅发现B2704(13例,占44.00%)和B27052(16例,占56.00%)二种亚型基因携带者。二者间多数临床表现差异不大,但携带B27052基因的AAU患者伴发强直性脊柱炎(ankylosing spondylitis, AS)的人数(7人,占24.24%)显著高于B2704基因携带者(1人,占3.74%)。 结论 B2704和B27052单独的亚型特异性与AAU无易感性关联;但B27052基因可能与并发AS有关。 (中华眼底病杂志, 1999, 15:139-142)     

INT2 and ERBB2 amplification and ERBB2 expression in breast tumors from patients with different outcomes

Summary The relationships of INT2 and ERBB2 amplification and of ERBB2 overexpression in primary breast tumors to prognostic factors, recurrence, and survival have generated considerable controversy. The rationale for this study is that long-term, recurrence-free survival is a more direct criterion for testing the validity of a tumor marker than correlation either with prognostic factors or with short-term recurrence and survival. We examined the association of recurrence with INT2 and ERBB2 amplification and ERBB2 expression by comparing primary breast tumors from patients surviving without recurrence for 8.5 years after diagnosis. the LTS group, to tumors from patients recurring within two years, the RR group. The RR (N = 63) and LTS (N = 61) samples were coded and examined for amplification by Southern blotting and for expression by immunohistochemistry. Comparison between the RR and LTS groups demonstrated that INT2 amplification was associated with a significantly (P = 0.018) higher (5.6-fold) risk of recurrence, an association that remained significant after controlling for lymph node (LN), tumor size (TS), and histograde (HG) status. ERBB2 amplification and expression were not associated with a higher recurrence risk. Survival analyses within the RR group, however, demonstrated significantly shorter survival time among cases with than without ERBB2 amplification (P = 0.018, median survival 16 vs 25 months), or ERBB2 expression (P = 0.019, median survival 15 vs 25 months), but not INT2 amplification. Univariate Cox proportional hazards regression models also demonstrated significantly shorter survival among cases with ERBB2 amplification (P = 0.016) or expression (P = 0.049), that remained significant in multivariate analyses (P = 0.022) for ERBB2 amplification. These results indicate a significant positive association between INT2 amplification and risk for tumor recurrence in the RR as compared to the LTS group. The relationship of ERBB2 amplification or overexpression to patient outcome is more complex. ERBB2 amplification and expression have a significant relationship with shorter survival among patients recurrent within two years, but their occurrence in tumors from women surviving without recurrence for 8.5 years suggests that ERBB2 status is not predictive of shorter survival for all breast cancers.     

Amplifications of oncogeneerbB-2 and chromosome 20q in breast cancer determined by differentially competitive polymerase chain reaction

Summary A new method of measuring gene copy number in small samples of DNA was used to measure amplification of theerbB-2 gene and of chromosome 20q in breast cancers. This method, termed differentially competitive polymerase chain reaction (DC-PCR) combines the advantages of two other techniques for measuring amplification by PCR, namely differential PCR and competitive PCR. The DC-PCR methodology was evaluated for sensitivity and specificity by comparing amplification oferbB-2 measured by DC-PCR with that obtained by fluorescencein situ hybridization (FISH) for 42 cases or Southern blotting and/or slot blot analysis for 34 cases. There was over 90 percent concordance with both FISH and Southern blotting and/or slot blot analysis.DC-PCR was used to further characterize the newly described amplicon at chromosome 20q. By analyzing DNA from 10 breast cancer cell lines at 7 different loci, we identified a potential common region of amplification of approximately 5 centimorgans at chromosome 20q13 bordered by loci D20S52 and RMC20C001-S1. One hundred and seventeen cases of primary breast cancer were evaluated for amplification at these two loci. Amplification at one or more loci, defined as > 1.5 fold higher copy number than that of normal DNA, was found in 25 cases (21%). Sixteen cases were amplified at only one of the two probes (12 cases for RMC20C001-S1 and 4 cases for D20S52), suggesting that the target gene lies between the two markers or that there are two independent target genes within a small chromosome region.     

Participation of low-threshold calcium spikes in excitatory synaptic transmission in guinea pig medial frontal cortex

We studied the activation of low-threshold calcium spikes (LTS) by excitatory postsynaptic potentials in pyramidal neurons from guinea pig medial frontal cortex with intracellular recording. We used extracellular bicuculline and phaclofen and intracellular QX-314 to block inhibitory synaptic potentials and sodium currents. Postsynaptic potentials were evoked by stimulation of layer I. We found that large (> 10-15 mV) excitatory synaptic potentials evoked from membrane potentials more negative than -75 mV were able to trigger LTS. The activation of LTS resulted in an increase of the rising slope or amplitude of the synaptic potentials depending on the size of the excitatory postsynaptic potential (EPSP). We used 100 microM NiCl2 to confirm the presence of LTS as part of the EPSPs. The N-methyl-D-aspartate (NMDA) and non-NMDA components of the excitatory synaptic potentials were isolated using (+/-)2-amino-5-phosphonovaleric acid (APV; 50 microM) or 6-cyano-7-nitroquinoxaline-2,3-dione (CNQX; 20 microM); both components could, independently, trigger an LTS. With recordings made with K+ acetate-filled electrodes, we show that the activation of LTS was critical to allow excitatory synaptic potentials to reach the threshold of action potential firing; also, this amplification of synaptic responses produced the firing of more than a single action potential by the postsynaptic cell. These results demonstrate that in cortical pyramidal neurons the activation of low-threshold calcium spikes results in the amplification of synaptic responses.     

一步法分析细胞色素P450 2D6酶活性缺陷等位基因CYP2D6A和CYP2D6B

 目的：CYP2D6A和CYP2D6B是引起细胞色素P4502D6(CYP2D6)酶活性缺陷的最主要的等位基因 ，对CYP2D6A和CYP2D6B的检测可准确(>92%)预测CYP2D6慢代谢者。本研究利用等位基因特异扩增法，建立了一步PCR法测定CYP2D6A和CYP2D6B等位基因。方法：等位基因特异扩增法分析CYP2D6A和CYP2D6B等位基因；右美沙芬作为探针药物测定表型。结果：经130例测定，说明本法更为快捷、更少污染。结论：本法的建立为该项测定应用于临床、指导临床合理用药奠定基础。     

上皮性卵巢肿瘤组织中端粒酶活性的表达及与临床病理因素相关性研究

目的:探讨端粒酶在卵巢癌发 生和发展中的作用,及端粒酶活性与临 床病理因素的相关性。方法:应用端粒 重复序列扩增技术(TRAP)检测45例卵 巢上皮性肿瘤及9例正常卵巢组织端粒 酶活性。结果:端粒酶阳性检出率在恶 性和交界性卵巢肿瘤组中分别为 83.33%(25/30)和5/7,差异无统计学意 义,P=0.5963;良性上皮性卵巢肿瘤及 正常卵巢上皮组织中未检测到端粒酶活 性,与前两组之间均差异有统计学意义 P<0.01。端粒酶的表达与临床病理因 素无明显相关性。结论:端粒酶在卵巢 癌发生和发展过程中可能具有重要作 用,并有望作为卵巢上皮性癌基因治疗 的靶点。     

红景天属植物DALP反应体系的建立

目的 利用直接扩增片段长度多态(DALP)这一新分子标记技术建立一套稳定的红景天属植物的DALP反应体系。方法 以红景天基因组DNA为模板,对DALP反应程序的一些重要参数进行摸索和优化试验。结果 建立了一套稳定性强、可靠性高的DALP应用反应体系;经过大量重复性实验,反应体系为20μL,Mg2 浓度为2.5 mmol/L,dNTPs浓度为1.25 mmol/L,模板DNA的量为60 ng,5 pmol/L选择性引物1μL,5 pmol/L反向引物3 μL,引物浓度比为1:3,Taq酶2 U。反应过程为:95℃预变性5 min、94℃变性30 s、50℃退火30 s、72℃延伸1 min;30个循环,再72℃延伸10 min,完成整个PCR反应。结论 该体系可有效地应用于红景天属药材的分类鉴定和地道性鉴定。     

一株汉坦病毒的分离及基因鉴定

目的分离汉坦病毒并采用分子生物学方法进行基因鉴定.方法组织细胞培养法和RT-PCR法.结果在黑线姬鼠体内分离出一株汉坦病毒,分别用HTN型和SEO型的特异引物对其进行基因扩增,同时以76-118株和L99株作对照,结果分离株经HTN型引物扩增出一条明亮带并同76-118株结果一致.结论分离株经基因鉴定为HTN型病毒.     

网状分枝扩增方法检测志贺毒素2基因

目的 建立一种快速、灵敏检测志贺样毒素2(STX2)的方法。方法 用网状分枝扩增技术(RAM)和PCR检测合成的志贺样毒素2基因和临床分离的菌株，确定该方法的灵敏度和特异性。结果 RAM最少能检测10个志贺样毒素2的DNA分子，与PCR具有同样灵敏度。用PCR和RAM检测临床标本和食品中分离的33株大肠埃希菌，其中26株stx2基因为阳性，2种方法检测结果一致。结论 RAM与PCR方法相同的灵敏度和特异性，但操作简便，并且是在等温条件下扩增核酸，成本较低，适合检测食品和临床标本中大肠埃希菌志贺样毒素2。     

鼻腔NK/T细胞淋巴瘤T-bet基因扩增及特异表达的研究

目的 探索鼻腔NK／T细胞淋巴瘤（N-NK／T—L）特异基因改变及其表达变化。方法 对同一病例的N-NK／T-L肿瘤细胞和外周血白细胞进行限制性酶切路标基因组扫描（RIGs），并结合相应虚拟基因组扫描（VGS）生物信息分析，及基因库检索确定异常基因信号；通过对上述结果发现的异常基因进行克隆和探针制备，对3例新鲜N—NK／T-L肿瘤组织和1例外周血标本进行了Southern和斑点印迹杂交分析，并对20例石蜡组织N-NK／T-L以及对照组包括17例同部位B细胞淋巴瘤、3例正常脾组织和5例慢性炎性鼻黏膜组织进行了原位杂交检测。结果 RLGS和VGS法显示N-NK／T-L肿瘤细胞中存在T-bet基因异常；经Southem和斑点印迹杂交检测证明在3例新鲜N-NK／T-L肿瘤细胞中有T-bet基因扩增；原位杂交显示T-bet基因在20例N-NK／T-L中阳性表达者为18例（90．0％），而B细胞淋巴瘤中仅为2例（11．8％），两者比较差异有统计学意义（P〈0．01）。在3例脾组织和5例慢性炎性鼻黏膜组织中均未有T-bet表达。结论T．bet基因在N-NK／T-L肿瘤细胞中存在基因扩增和过表达，T-bet基因的异常表达可能在N-NK／T—L的发生中起一定作用，并有必要对其是否可作为分类依据和辅助诊断的指标做进一步研究。