医学信息学的研究领域及人才培养

医学信息学(MedicalInformatics,又称医药信息学)是计算机科学、信息科学与医学科学结合,新近形成的前沿多学科交叉的科学,它以信息论、系统论、计算机科学技术为理论基础,几乎全方位地涉及所有的医药卫生领域,已成为现代和未来生物医学发展的基石。目前,医学信息学应用的领域,面临人才短缺的现象,本文论述了在生物医学工程学科中,建立医学信息本科专业方向,通过相关课程体系的设置,培养符合社会需要的医学信息人才。     

Extracellular matrix activity and caveolae events contribute to cell surface receptor activation that leads to MAP kinase activation in response to UV irradiation in cultured human keratinocytes

Activation of cell surface components has been implicated in the activation of downstream signaling cascade in response to UV irradiation, and yet the identity and the interaction of those components have been scantly documented. Accumulating evidence indicates that caveolae encapsulating caveolins is the location for those interactions. We found in cultured human keratinocytes that UV irradiation induced both caveolin-1 and EGFR phosphorylation. Filipin, a caveolae disruptive agent, inhibited UV-induced caveolin-1 activation. Na+-K+-ATPase catalyzes active transport of Na+ and K+ across plasma membrane of mammalian cells, inactivation of which has recently been shown to be involved in the activation of signal transduction pathways including MAP kinase cascade. We found in this study that UV inactivated Na+-K+-ATPase in time-dependent manner, Na+-K+-ATPase activity started to decrease 5 min post UV irradiation and reduced to 60% of its original activity within 1 h. Pretreatment with Flipin and MMP inhibitor recovered Na+-K+-ATPase activity lost by UV irradiation. ECIS analysis indicated that both EGF treatment and UV irradiation increased membrane electric activity which was inhibited by MMP inhibitor and Filipin. Further study showed that pretreatment of human keratinocytes with MMP inhibitor or Filipin inhibited UV-induced phosphorylation of p38 and JNK, which was however not observed in LnCap cells, a prostate cancer cell line lacking caveolin-1. UV irradiation also induced ectodomain shedding of HB-EGF in a time-dependent manner in keratinocytes. Collectively, we conclude that UV-induced MAP kinase activation is mediated by cell surface receptor activation due to the matrix activity and membrane caveolae function and inactivation of Na+-K+-ATPase.     

应用PCR-酶切法进行脊肌萎缩症基因诊断

目的探讨脊肌萎缩症(SMA)的基因诊断方法.方法基于运动神经元生存基因(SMN)的两个同源拷贝碱基上的差异,应用PCR-酶切分析法对10例临床和病理诊断为Ⅰ、Ⅱ、Ⅲ型SMA的患者及其直系亲属16人、25例正常对照进行SMN基因检测.结果 10例SMA患者中9例患者缺失SMN第7、8号外显子,1例患者仅缺失第7号外显子;正常对照组及患者亲属均未发现外显子缺失.结论 PCR-酶切检测SMN基因第7号、8号外显子缺失是诊断儿童型脊肌萎缩症可靠的基因诊断方法.     

Inhibition of VEGFR2 prevents DMBA-induced mammary tumor formation

Preinvasive mammary pathologies in humans and rat chemical carcinogenesis model systems have an increased microvascular density relative to normal tissue. This suggests the possibility of preventing invasive breast cancer by inhibiting angiogenesis. Vascular endothelial cell growth factor (VEGF) is a potent angiogenic growth factor, commonly involved in tumor-induced angiogenesis. Here, we show that both VEGF and VEGFR2 expression increase with histological progression to invasive disease in the rat 7,12-dimethylbenz[a]anthracene (DMBA) model. Other VEGF receptors, VEGFR1, neuropilin 1 and neuropilin 2, are constitutively expressed throughout progression. To examine whether VEGF signaling is functionally relevant to tumor-induced endothelial tubule formation in vitro and for tumor formation in vivo, we utilized the VEGFR2 inhibitor, ZD6474. In vitro endothelial cell tubulogenesis induced by isolated mammary organoids or carcinoma in situ from DMBA-treated rats is inhibited by ZD6474, in a dose-dependent fashion. The administration of ZD6474 to DMBA-treated rats inhibits the formation of atypical ductal hyperplasia and carcinoma in situ by greater than 95% (P < 0.05), when administered 1 week or 6 weeks post-DMBA initiation. Invasive disease was absent in all ZD6474 cohorts. These data support the hypothesis that progression of DMBA-induced preinvasive mammary pathologies to palpable disease requires angiogenesis via a VEGF-dependent mechanism.     

高压力对体外培养动脉中膜平滑肌细胞凋亡及其相关蛋白的影响

目的观察血管平滑肌细胞在单纯高压力作用下凋亡及其相关蛋白Bcl-2和Bax的变化，探讨力学因素在血管重建中的作用。方法应用血管体外应力培养系统，分别在压力100mmHg和160mmHg条件下培养猪颈总动脉1、4和7d，新鲜血管为对照。应用TUNEL法、透射电镜等观察血管平滑肌细胞的凋亡；用免疫组织化学方法检测血管平滑肌细胞内Bcl-2和Bax的表达。结果高压力作用下，血管平滑肌细胞凋亡第1d较多，而后逐渐减少；Bcl-2蛋白表达持续增强；Bax蛋白第1d较多，而后逐渐减少。结论高压力可以影响血管平滑肌细胞的凋亡，凋亡相关蛋白Bcl-2持续增加，Bax先增加后减少，揭示高压力可能通过调节Bcl-2和Bax来调控血管平滑肌细胞的凋亡。     

抗肝癌细胞噬菌体单链抗体库的构建及筛选

构建抗人肝癌细胞单链抗体库 ,从中筛选与肝癌细胞特异结合的高亲和力单链抗体。从HepG2细胞免疫的BALB/c小鼠脾脏提取总RNA ,RT PCR扩增小鼠抗体重、轻链可变区基因 ,用 (Gly4Ser) 3 连接肽基因 ,经重叠延伸反应 ,在体外将VH 和VL 连接成单链抗体 (scFv)基因 ,并克隆入噬菌粒载体pCANTAB5E中 ,构建噬菌体单链抗体库。以HepG2细胞为抗原对抗体库进行淘选 ,ELISA法鉴定各单克隆与肝癌细胞的结合活性 ,并对阳性克隆进行表达。成功构建了库容为 1 1× 10 6抗肝癌细胞的噬菌体单链抗体库 ,经筛选得到了与HepG2细胞具有较强结合能力的单链抗体 ,实现了scFv在大肠杆菌中的可溶性表达。序列测定结果表明 ,VH 和VL 基因符合小鼠抗体可变区特征 ,scFv基因拼接正确     

流式细胞术检测细胞毒方法的建立

目的：建立一种用流式细胞仪测定细胞介导细胞毒活性的方法。方法：用羧基荧光素二醋酸盐琥珀酰亚胺酯(CFSE)标记靶细胞，再用碘化丙碇(PI)标记DNA筛选细胞膜已破坏的靶细胞。效靶比为100：1—6．25：1，共孵育时间为1-6小时，流式细胞仪收集1000个靶细胞并测定被杀细胞的百分率。结果：CFSE是合适的标记靶细胞的荧光染料，18小时后也能很好地区分效靶细胞；靶细胞的自然死亡率低于5％；杀伤百分率随着效靶比和共孵育时间的增加而增加。最佳效靶比为50：1—25：1，共孵育时间为2—4小时。结论：CFSE／PI双荧光染料标记的流式细胞分析检测细胞毒具有多个优点：避免放射性试剂的应用，敏感性增强，单细胞水平的分析。     

RT-PCR-ELISA方法检测甲肝减毒活疫苗病毒滴度的初步研究

目的 应用核酸扩增产物测定的固相杂交酶联显色法(RT-PCR-ELISA)检测甲肝减毒活疫苗病毒滴度。方法 应用RT-PCR-ELISA。将标记有生物素的寡核苷酸引物所扩增的疫苗病毒基因产物。与微孔反应板上的特异性探针进行快速杂交，通过辣根过氧化物酶标记的链亲和素进行酶联显色。读取吸光度(A值)。判断结果。应用此法检测了11批甲肝活疫苗滴度。并与常规细胞培养法(CCID50)比较。结果 本方法与细胞培养法的敏感性相仿，具有简便、快速、特异的优点。结论 RTPCR-ELISA法有望代替常规细胞培养法应用于甲肝减毒活疫苗病毒滴度的检测。     

血管紧张素原基因5′端核心启动子区(-6)A-G和(-20)A-C变异与哈萨克族人原发性高血压相关性分析

目的　研究血管紧张素源 (angiotensinogen,AGT)基因核心启动子区域 (- 6 ) A- G和 (- 2 0 )A- C位点变异与哈萨克族人原发性高血压相关关系。方法　采用经典的饱和酚 /氯仿抽提法提取哈萨克族正常人 74名和高血压患者 12 5例白细胞基因组 DNA,通过 PCR、单链构象多态性、限制性片段长度多态性和测序等技术 ,鉴定不同个体 AGT基因核心启动子区域 (- 6 )、(- 2 0 )位等位基因的类型 ,观察在高血压组和正常血压组不同基因型的分布和等位基因频率的差异。结果　 (1)哈萨克族人 AGT基因 - 16 4～ 73区域仅存在 (- 6 ) A- G、(- 2 0 ) A- C两种变异。(2 ) AGT基因 (- 6 )位点 AA、AG、GG基因型的频率在高血压组和正常血压组分别为 0 .39、0 .4 5、0 .16和 0 .4 9、0 .4 9、0 .0 2 ,两组之间差异存在显著性 (χ2 =8.5 6 ,P=0 .0 14 )。A、G等位基因频率分别为 0 .6 2、0 .38和 0 .73、0 .2 7,差异存在显著性 (χ2 =5 .35 ,P=0 .0 2 1)。(3) AGT基因 (- 2 0 )位点 AA、AC、CC基因型频率在高血压组和正常血压组分别为 0 .6 9、0 .2 6、0 .0 5和 0 .6 5、0 .32、0 .0 3,差异无显著性 (χ2 =2 .4 2 ,P=0 .30 ) ;A、C等位基因的频率分别为 0 .82、0 .18和 0 .82、0 .18,差异无显著性 (χ2 =0 ,P=0 .99)。(4) AGT基     

基于核磁共振技术的生物阻抗成像研究进展

我们对最新发展的阻抗成像方法--核磁共振电阻抗成像(Magnetic resonance electrical impedance tomography,MREIT)技术进行了综述,简要介绍了CT(Computerized tomography,CT)和MRI(Magnetic resonance imaging,MRI)成像技术的基本原理,详述了MREIT技术基本理论和目前MREIT算法的发展状况,并就MREIT的发展前景及目前存在的问题进行了分析.