胃癌组织p16基因蛋白表达的意义

目的　检测 p1 6基因蛋白在胃癌组织、癌旁组织中的表达及其分布特点 ,分析其与胃癌临床病理学特征及预后的关系 .方法　采用 S- P免疫组织化学法对 53例胃癌组织及 35例癌旁组织进行 p1 6蛋白的定位观察 .结果　各病理类型胃癌组织、癌旁组织均有 p1 6基因蛋白表达 .阳性率分别为 62 .3% (33/53)和 88.6% (31 /35) ,阳性细胞的棕黄色颗粒主要位于细胞核 .胃癌 p1 6基因蛋白表达与性别、年龄、肿瘤部位在统计学上无差异 (P>0 .0 5) ;而与组织学类型、病理分级、淋巴结转移、临床病理分期在统计学上有差异 (P<0 .0 5) .p1 6蛋白阳性者 5年生存率 51 .0 %高于 p1 6蛋白阴性者 2 0 .0 % (P<0 .0 5) .结论　 p1 6基因缺失和表达水平的改变与胃癌发生、发展密切相关 ,检测 p1 6基因蛋白表达可作为辅助临床判断胃癌的生物学行为及推测预后的指标     

人原发性肝癌中p16基因表达及CpG岛甲基化状态的研究

目的　进一步探讨人原发性肝癌中 p16基因 m RNA转录水平变化与其基因启动子区 Cp G岛甲基化的关系 ,及其在肝癌发生中的意义。方法　采用狭缝印迹杂交检测 2 0例人原发性肝癌及相应的癌旁、远癌组织及 2例正常人肝组织中 p16基因 m RNA表达水平 ,以甲基化特异性 PCR分析各组织中 p16基因启动子区 Cp G岛的甲基化状况 ,并进行统计分析。结果　 2 0例人原发性肝癌中 14例 (70 % ) p16 m RNA水平比远癌组织显著降低 ;13例 (6 5 % )显示 p16基因启动子区 Cp G岛甲基化 ,其中 84 .6 % (11例 )伴 p16 m RNA转录水平降低。结论　人原发性肝癌中存在高频率的 p16基因表达失活 ,其主要机制可能是启动子区 Cp G岛甲基化抑制了基因的转录 ,在人原发性肝癌的发生发展中有重要作用。其临床诊断和治疗意义有待进一步深入研究。     

C57小鼠源性淋巴瘤的基因枪途径抗肿瘤免疫研究

[目的]诱导C57小鼠建立有效的抗肿瘤免疫.[方法]用基因枪途径给C57小鼠腹部接种含有粒巨噬细胞集落刺激因子(GMCSF)基因的质粒,24h后在同一部位注射FBL3肿瘤细胞破碎后的上清液,15d后用3×106个FBL3肿瘤细胞皮下接种攻击.[结果]肿瘤的生长受到抑制,小鼠的生存时间明显延长.[结论]基因枪途径局部接种含有GMCSF基因的质粒,可增强机体的抗肿瘤免疫,抑制肿瘤细胞的生长.     

Modelling Germline Mosaicism and Different New Mutation Rates Simultaneously for Appropriate Risk Calculations in Families with Duchenne Muscular Dystrophy

For several genetic diseases two biological phenomena have been recognised as important: germline mosaicism; and different new mutation rates in males and females depending on mutation type. Both principles have been investigated separately and their influence on risk estimation in families has been exemplified in the literature. The aim of this paper is to present a general model that includes mosaicism and different new mutation rates. Mosaicism is introduced by defining additional alleles at the disease locus in combination with adapted segregation rules. Taking Duchenne muscular dystrophy as an example, we derive the conditions which have to be fulfilled for a population in mutation selection equilibrium. Our approach describes the model at the population level and not in individual subjects. This has the advantage of being able to use well known algorithms for the calculation of likelihoods in pedigrees, and to include additional diagnostic information such as marker genotypes and carrier deletion test results. We demonstrate the impact of the new model on a typical pedigree. In families where the patient is not available, the distinction between point mutations and deletions is important, since often molecular diagnostic tests for females can only screen for deletions. Negative deletion test results can now be included in the risk calculations.     

PTEN基因敲除降低辐射敏感性及其机制

目的 探讨PTEN基因敲除对辐射敏感性的影响及机制。方法 采用流式细胞术检测MEF1和MEF1/PTEN^－/－细胞内ROS水平;采用Western blot方法,检测H₂O₂和DPI预处理后AKT激酶的表达变化;采用细胞克隆形成率试验分析细胞对⁶⁰Co γ射线的敏感性。结果 PTEN基因敲除后细胞ROS水平增加,辐射敏感性降低。H₂O₂和DPI预处理后影响MEF1细胞AKT激酶活性,但对MEF1/Pten^－/－细胞无影响。 结论 PTEN基因敲除阻断了ROS对AKT的介导,AKT激酶持续活化,可能是辐射敏感性降低的重要原因。     

Molecular basis of severe myoclonic epilepsy in infancy

Severe myoclonic epilepsy (SMEI) or Dravet syndrome is caused by mutations of the SCN1A gene that encodes voltage-gated sodium channel alpha-1 subunit. Recently, we generated and characterized a knock-in (KI) mice with an SCN1A nonsense mutation that appeared in three independent SMEI patients. The SCN1A-KI mice well reproduced the SMEI disease phenotypes. Both homozygous and heterozygous knock-in mice developed epileptic seizures within the first postnatal month. In heterozygous knock-in mice, trains of evoked action potentials in inhibitory neurons exhibited pronounced spike amplitude decrement late in the burst but not in pyramidal neurons. We further showed that in wild-type mice the Nav1.1 protein is expressed dominantly in axons and moderately in somata of parbalbumin (PV) – positive inhibitory interneurons. Our immunohistochemical observations of the Nav1.1 are clearly distinct to the previous studies, and our findings has corrected the view of the Nav1.1 protein distribution. The data indicate that Nav1.1 plays critical roles in the spike output from PV interneurons and further, that the specifically altered function of these inhibitory circuits may contribute to epileptic seizures in the mice. These information should contribute to the understanding of molecular pathomechanism of SMEI and to develop its effective therapies.     

应用HMM和加权距离判别法的真核基因识别程序研究

根据现代科学对基因的认识，应用了隐马尔科夫模型(HMM)的算法，以大量核酸序列为信息来源，通过计算机计算来寻找未知基因的大体位置；再通过基因的固有结构特征及密码子使用的偏向性，使用加权距离判别法来准确地定位基因，以图形及文本的形式输出，从而极大地方便了实验室的研究工作。考虑到基因的许多特征还不为人们所了解，而且不同物种之间基因结构又有一定的差异，所以还开发了程序自学习功能，不断地存储已知的基因，再据此改变一些已有固有数据，以便更好地适应和了解不同生物基因结构的特异性，更加准确地寻找未知基因的位置。     

原位杂交法检测BP1基因在乳腺癌组织中表达

目的探讨BP1同源盒基因在乳腺癌中的表达及其与临床病理指标的关系。方法收集165例乳腺癌临床和病理资料,采用原位杂交法检测BP1的表达,同时用二步法进行ER、p53、PCNA、bcl2、cerbB2免疫组化染色。结果BP1基因表达率为67.88%,免疫组化:ER70.30%、p5349.09%、PCNA74.55%、bcl253.33%、cerbB275.52%。BP1与bcl2具有相关性(P<0.01),且均与ER相关(P<0.05),与p53呈负相关(P<0.05)。BP1与PCNA、cerbB2、患者年龄、组织学类型、淋巴结转移等无相关性。结论BP1可能通过某种非依赖p53基因调控机制,与bcl2、ER协同抑制肿瘤细胞的凋亡而参与乳腺癌的发生。     

CD44v7/8基因表达与宫颈癌关系的探讨

目的探讨宫颈癌组织中CD44v7/8基因的异常表达及临床意义。方法1986～2000年沈阳医学院附属中心医院采用免疫组化的方法随机测定59例宫颈癌、18例尖锐湿疣和18例慢性宫颈炎组织中CD44v7/8基因的表达情况。结果宫颈癌、尖锐湿疣及慢性宫颈炎3种疾病中CD44v7/8表达阳性率分别为76.27%、11.11%和11.11%,宫颈癌组的CD44v7/8表达分别高于慢性宫颈炎组及尖锐湿疣组,且差异非常显著(P<0.01)。慢性宫颈炎组及尖锐湿疣组比较差异无显著性(P>0.05)。结论CD44v7/8蛋白的表达增强与宫颈癌的发生、发展及和局部浸润转移有关。