Dynamic analysis of DNA damage induced miRNAs in colon cancer cells

It is known that microRNAs （miRNAs） expression profile shows substantial changes in cells under DNA damage. Here, we did miRNA microarray and quantitative real-time PCR to comprehensively identify the differentially expressed miRNAs in colon cancer cell lines HCT116 p53＋/＋ and HCT116 p53-/-. Cluster analysis revealed a panel of differentially expressed miRNAs which are regulated by p53 and/or UV-C induced DNA damage. These altered miRNAs tend to be located in chromosomes 13, X and 17. Moreover, pathways enrichment analysis estimated that MAPK pathway, focal adheren pathway, p53 pathway and Wnt pathway were mediated by these miRNAs to exert their functions in DNA damage response. Additionally, we found that miR- 320a, one of the UV-C induced miRNAs, play a role in protecting cells from DNA damage. Taken together, our results show that miRNAs are dynamic regulated in p53- dependent or -independent manners in different cell contexts and different situations following DNA damage.     

h-1保持各种独立语言的条件

设h：X＊→X＊是同态映射,主要研究了h-1保持各种独立语言的条件.得到了h-1保持ρc-独立语言,ρd-独立语言以及ρb-独立语言的充分必要条件都是h-1（1）={1}.此外,证明了若h：X＊→＊是同态映射,则h-1保持ρe-独立语言.     

A simulation study on the thermal and wetting behavior of alkane thiol SAM on gold (111) surface

Molecular dynamics simulations have been performed to investigate the structural,thermal and wetting properties of self-assembled monolayer(SAM) of alkane thiol on gold surface.The specific heat capacity of the gold SAM surface was found to linearly increase with the temperature in the range 100–300 K.It was found to drop down at 400 K and this decrease might be attributed to the disorder of the SAM chains.Hydration of gold SAM surface for two different terminal groups,namely methyl(hydrophobic),and hydroxy(hydrophilic) was studied at room temperature.The difference in their wetting behavior and the structure of their interfacial water were examined from the estimation of the z density profile,radial distribution function,hydrogen bonds and orientation of water dipoles in the interfacial region.The present simulation results suggest that the wetting behavior of the gold SAM surface can be modified by altering the terminal functional group of the SAM chains.     

小鼠金属硫蛋白基因-I 在CHO细胞中稳定表达及其在医疗方面的应用

将小鼠的MT-I基因插入pSV₂-dhfr质粒的EcoRI位点,构建了具有SV₄₀和MT双启动子并正向插入MT-I基因的表达载体。用改良的磷酸钙/DNA沉淀法将表达载体导入CHO-dhfr-细胞内,用不含次黄嘌呤(H)和胸腺嘧啶(T) 的选择培养基筛选出稳定表达MT阳性克隆D-22,经检测10⁶细胞的 MT 表达量约为1.8 μg,D-22细胞对Cd²⁺浓度抗性较之CHO-dhfr-细胞高14倍。为了研究金属硫蛋白对正常细胞所具有的保护作用,将不同浓度的顺铂分别处理无MT表达的CHO-dhfr-细胞和有MT表达的D-22细胞。实验发现顺铂对D-22细胞和CHO-dhfr^-细胞 50%生长抑制浓度(IC50)分别是0.145μmol/L 和0.04μmol/L。上述研究表明MT对正常细胞有一定的保护作用,因而通过诱导正常细胞提高MT的表达量,同时使用MT阻断剂阻断肿瘤组织的MT合成,这样可能会为治疗某些顽固肿瘤开辟一条新途径。     

甲基异柳磷气相色谱定量法

甲基异柳磷原油用气相色谱法测定,其色谱条件如下:不锈钢柱1m×3mm、柱内填充物为5%OV-3涂于ChromosorbW-HP60—80目担体,以氮气作载气,柱温190℃,用氢火焰检测器,癸二酸二正丁酯作内标,测定误差<±1.2%.     

KM小鼠与BALB／c小鼠五项免疫学指标的初步观察

采用五种免疫功能测定法对８３２只健康ＫＭ小鼠和８３只ＢＡＬＢ／ｃ小鼠进行免疫学功能指标的测定,结果表明ＣｏｎＡ诱导小鼠脾淋巴细胞转化能力ＯＤ值分别为０．０１４８－０．０１９２和０．０１２０１～０．０２０６,二硝基氟苯诱导小鼠迟发型变态反应（耳肿胀法）小鼠耳重差分别为１０．３９～１２．１７ｍｇ和１１．４６８～１６．２３４ｍｇ;血清溶血素抗体积数分别为７８．９８～９１．３０和１０６．７３～１１６．０７     

Mad2蛋白在有HeLa细胞有丝分裂期的动态定位

准确的染色体分离依赖于有丝分裂过程的精确调控,包括有丝分裂的时间,及纺锤体检查点的正确调控等。通过动态观察有丝分裂染色体的运动可对上述研究进行精确定量。结果显示,我们利用逆转录病毒系统成功构建了稳定融合表达绿色荧光蛋白GFP-H2B的HeLa细胞系,结合细胞同步化方法,建立了一套利用活细胞荧光共聚焦显微镜观察HeLa细胞有丝分裂的实验体系。     

基于核方法的分类型属性数据集模糊聚类算法

针对分类型属性数据的聚类问题．将核方法的思想推广到快速、高效率的模糊c-均值算法,构造了基于核函数的模糊核c-均值聚类算法．该算法通过使用经验核矩阵充分利用了数据间的“相异性”信息,并且避免了模糊k-modes算法中每次迭代均要直接计算类中心的缺点,提高了聚类的精确度和稳定性．同时该算法对模式(类中心)的初始值选择不敏感．时实际的线性可分的和线性不可分的分类型属性数据集的仿真实验证明了该算法的有效性．     

表达结核分枝杆菌休眠相关抗原Rv2031c-Rv2626c融合蛋白

利用大肠埃希菌-分枝杆菌穿梭表达载体pDE22,构建能够表达结核分枝杆菌（Mycobacterium tuberculosis, MTB）休眠相关抗原Rv2031c-Rv2626c融合蛋白的重组耻垢分枝杆菌（Mycobacterium smegmatis, M.s）。采用聚合酶链反应（PCR）方法,从MTB H37Rv基因组DNA中扩增MTB休眠相关抗原Rv2031c和Rv2626c基因片段并克隆入pMD18-T载体,序列测定正确后分别亚克隆入大肠埃希菌-分枝杆菌穿梭表达载体pDE22,将重组载体pDE22-Rv2031c-Rv2626c电穿孔导入M.s,42℃热诱导表达目的蛋白,并进行SDS-PAGE和Western-blot分析。利用PCR方法扩增获得MTB休眠相关抗原Rv2031c和Rv2626c基因片段,大小分别为435bp和480bp,基因测序与Genebank公布的基因序列完全一致。SDS-PAGE分析结果表明重组载体pDE22-Rv2031c-Rv2626c电穿导入M.s后能够特异性表达目的蛋白,大小约为35kDa,与理论值相符。Western-blot鉴定结果表明抗Rv2031c和抗Rv2626c的单克隆抗体均能够与目的蛋白发生特异性的反应,大小相一致。成功构建表达MTB休眠相关抗原Rv2031c-Rv2626c融合蛋白的重组M.s,并命名为Rv2031c-Rv2626c-rM.s,为其用于结核新型疫苗的研究奠定了基础。