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。     

The role of Self-Defined Race/Ethnicity in Population Structure Control

Population-based association studies are powerful tools for the genetic mapping of complex diseases. However, this method is sensitive to potential confounding by population structure. While statistical methods that use genetic markers to detect and control for population structure have been the focus of current literature, the utility of self-defined race/ethnicity in controlling for population structure has been controversial. In this study of 1334 individuals, who self-identified as either African American, European American or Hispanic, we demonstrated that when the true underlying genetic structure and the self-defined racial/ethnic groups were roughly in agreement with each other, the self-defined race/ethnicity information was useful in the control of population structure.     

尾型同源盒转录因子-2与癌前因素及胃癌的关系

尾型同源盒转录因子-2（CDX-2）在肠上皮细胞正常发育分化和癌组织发生发展过程中起关键作用。CDX-2突变体及其异位表达可诱导胃黏膜肠化生和胃癌的发生。对于进展期胃癌患者，CDX-2与其他相关因子的联合检测对于判断其预后有着很好的临床应用价值。肝肠钙黏蛋白（LI-cadherin）可能在CDX-2调节肠细胞分化过程中起关键作用。     

CAD基因原核表达载体的构建及表达产物的活性鉴定

目的构建pCool—GST—ICAD／CAD的表达载体，并存大肠杆菌BL21（DE3）中表达具有生物学活性的CAD核酸酶？方法用PCR扩增CAD基因，将扩增产物克隆入pCool—GST—ICAD载体中构建出pCool—GST—ICAD／CAD表达载体。经酶切和电泳鉴定正确后，在大肠杆菌BL21（DE3）中诱导表达，表达产物经亲和层析、离子交换层析及凝胶过滤等方法分离纯化。最后用SDS—PAGE和DNA降解实验进行鉴定。结果构建了pCool—GST—ICAD／CAD原核表达载体，重组载体转化后表达出毫克级水平的GST—ICAD／CAD蛋白复合体。经分离纯化后得到纯度很好的CAD—ICAD篮白复合体，在SDS—PAGE电泳上旱现清晰的两条蛋白带。经DNA降解实验证明纯化所得的CAD蛋白具有非特异性降解DNA的核酸酶作用。结论成功制备了具有生物学活性的CAD核酸酶，为进一步研究细胞凋亡的作用机制提供了有效的制剂。     

多药耐药基因转染骨髓造血细胞移植小鼠的安全性研究

目的 探讨多药耐药基因(mdrl)转染骨髓造血细胞移植后,其在体内分布和安全性.方法 骨髓造血细胞转染mdrl基因后移植入BALB/C鼠,免疫组织化学和RT.PCR观察mdrl基因在骨髓、外周血及重要脏器的表达;监测外周血白细胞变化及重要脏器病检分析其安全性.结果 P-糖蛋白(P-gP)在骨髓表达率随时间降低,各时间组差异无统计学意义(x2=3.74,P＞0.05),在外周血表达第2月最高,为(9.95±1.84)%,各时间组差异无统计学意义(x2=2.31,P＞0.05),在重要脏器无表达;移植未转染组与移植转染组外周血白细胞计数至移植60 d后,两者差异有统计学意义(t=6.173,P＜0.05),病检除肝和肾有炎性渗出和水肿病变外,其余无异常.结论 mdrl基因在骨髓和外周血有持续较高表达,在重要脏器无表达;mdrl基因转染对造血恢复及重要脏器无明显影响.