蓖麻毒素A链的基因克隆

作为导向药物蓖麻毒素A(Ricin-A)链在大肠杆菌中表达时不含糖基侧链,在体内半衰期长,可提高共作为导向药物的疗效。我们根据Ricin基因核苷酸序列,设计Ricin-A的上、下游引物,通过PCR(多聚酶链式反应)方法,扩增出Ricin-A链基因。与pUC_(19)载体连接,转化到JM103大肠杆菌中,得到重组克隆。对其进行几种酶切鉴定,证明酶切位点正确,又经序列分析,读出与文献发表的Ricin-A序列只有两个碱基不同,但无氨基酸残基的改变。有关Ricin-A的表达工作正在进行中。     

广西木鼻白蚁属四新种

木鼻白蚁属[Stylotermes Holmgren(syn.Operculitermes Yu et Ping)]是一个较为特殊的类群。一般为害活的树干,外形虽近似木白蚁,但属于鼻白蚁科(Rhinotermitidae)Holmgren,K.et N.(1917)最先建立木鼻白蚁亚科(stylotermitinae)仅有一种。以后经多数专家先后发表了八个新种,并对其科属地位作出了几种不同的处置。本文同意Emerson,A.(1971)意见,把本属作为鼻白蚁科的一个亚科。现在根据广西的标本经鉴定有四个新种,记述于后。     

缺氧对离体鸡胚前脑神经细胞生长的影响

在缺氧(95％N_2和5％CO_2)条件下进行8d鸡胚前脑的纯神经细胞培养。培养24,48和72h后,MTT微量比色法检测显示,甲(目替)明显减少,表明神经元已遭严重损害,同时,培养液中葡萄糖被急剧地消耗。但是,即使把糖浓度提高到800—1200mg/100ml,缺氧仍造成神经细胞死亡。结果提示,胚胎脑神经细胞对缺氧敏感,胶质细胞对缺氧神经元的保护可能不在于提供糖原。     

Evaluation of the biofilm-forming ability and genetic typing for clinical isolates of Pseudomonas aeruginosa by enterobacterial repetitive intergenic consensus-based PCR

Biofilm formation is an important phenotype associated with chronic Pseudomonas aeruginosa infections. In the present study, a total of 48 P. aeruginosa strains isolated from clinical specimens were examined for their biofilm-forming ability using a microtiter plate method. The different biofilm-forming abilities were demonstrated among the strains; however, most strains formed a larger biofilm than strain PAO1, a reference strain. The genetic typing was also carried out by enterobacterial repetitive intergenic consensus-based polymerase chain reaction. Although they were divided into five groups (A to E), most of the strains showing the higher biofilm-forming ability were found to be in groups D and E, suggesting a significant relationship between the biofilm-forming ability and the genetic group.     

陕西省汉族人群11号染色体10个STR基因座的遗传多态性研究

为了分析陕西汉族人群中11号染色体上10个短串联重复序列(short tandem repeat, STR)基因座的多态性,采用荧光标记基因扫描方法,对11号染色体上的D11S1760、D11S4102、D11S4116、D11S4207、D11S4162、D11S914、D11S4127、D11S917、D11S4146和^D11S915基因座的遗传多态性进行分析。结果显示：D11S1760、D11S4102、D11S4116、D11S4207、D11S4162、D11S914、D11S4127、D11S917、D11S4146和D11S915基因座分别检出17、11、15、11、4、6、7、12、11和13个等位基因,41、18、36、30、8、10、16、30、29和32个基因型,等位基因型符合Hardy-Weinberg平衡（P>0.05）。其杂合度分别为86.72%、67.95%、83.90%、85.96%、58.18%、57.63%、72.60%、72.73%、77.87%和86.40%,表明11号染色体上的这10个STR基因座在汉族人群中有较好的多态性,是理想的遗传标记物。     

Leaf Volatiles Induced by Mechanical Damage from Diverse Taxonomic Tree Species

Plant volatiles induced by wounding play key roles in plant-insect and plant-plant interactions. To deeply understand the mechanism of their induction by wounding and their functions in interplant communications, four diverse tree species: ashleaf maples ( Acer negundo L.), hankow willow ( Salix matsudana Koidz.), Chinese white poplar ( Populus tomentosa Carr.) and poplar opera 8277　( P. simonii×P. pyramibalis cv.), were used as materials. The blends of volatiles collected after damage were detected with GC-MS. Most of the induced compounds reach high concentrations in 5 h. They are acyclic monoterpenes, fatty acid derivatives, and aromatic compounds. To authors' knowledge, dimethyl adipate, diisobutyl succinate and benthothiazole have never been reported in previous herbivore insect-plant systems. After being damaged 2 h, green leaf volatiles were released in large amount. The repellents were detected in higher concentration after 24 h. The time of releasing is different within different species, but many kinds of volatiles widely existed in different trees. There were some difference among species. Health ashleaf maple released more terpenoids, but poplars and willow produced more aromatic compounds.     

天麦消渴片通过miRNA改善糖尿病大鼠血糖的机制

目的探讨天麦消渴片对糖尿病大鼠体重、血糖、血脂和胰岛素等相关代谢指标的影响,并且利用miRNA表达谱芯片和实时定量RT-PCR探讨天麦消渴片降血糖的机制。方法 SD大鼠通过高脂饮食/注射STZ法构建糖尿病大鼠模型。将SD大鼠分为小剂量天麦消渴片组[8只,给予50 mg/(kg·d)的天麦消渴片粉末悬浊液]、大剂量天麦消渴片组[8只,给予100 mg/(kg·d)的天麦消渴片粉末悬浊液]、糖尿病模型组(8只,给予等体积生理盐水)和正常对照组(8只,给予等体积生理盐水),均连续灌胃8周。每2周测定SD大鼠空腹血糖(FBG)和体重。7周末进行口服糖耐量实验(OGTT),测空腹和葡萄糖负荷后血糖。8周末测定大鼠空腹血糖、血清胰岛素和血脂水平,观察天麦消渴片对糖尿病大鼠血糖和血脂的改善作用。取大鼠胰腺组织进行miRNA表达谱芯片实验,并运用实时定量RT-PCR验证芯片结果,以期探讨天麦消渴片对糖尿病大鼠降血糖的机制。结果干预后,大剂量天麦消渴片组大鼠较糖尿病模型组空腹血糖和OGTT曲线下面积(AUC)显著下降。干预8周后,大剂量天麦消渴片组空腹血清胰岛素(FINS)和胰岛素抵抗指数(HOMA-IR)较糖尿病模型组显著降低(P0.01)。干预8周后,大剂量天麦消渴片组血总胆固醇(TC)和甘油三酯(TG)较糖尿病模型组显著降低(P0.05)。大剂量天麦消渴片组胰腺较糖尿病模型组有18个miRNA上调,3个miRNA下调。结论天麦消渴片不仅能有效降低糖尿病大鼠FBG,改善胰岛素敏感性,还能调节脂代谢。天麦消渴片可能是通过上调胰腺miR-375和miR-30d水平,刺激胰岛β细胞增殖,抑制胰岛α细胞增殖,增加胰岛素基因表达;上调胰腺let-7b、let-7e、miR-142-5p和miR-375,抑制细胞因子及受体相互作用通路和MAPK通路的功能,从而改善糖尿病大鼠血糖和胰岛素抵抗状态。     

1个新巨胚等位基因的鉴定与表达分析及其性状考察

该研究以‘超2-10’水稻和‘上师大5号’巨胚水稻为材料,分析了2种水稻的胚重、胚与糙米质量比、巨胚性状的遗传,克隆和分析了其巨胚基因(GE)序列,并对巨胚基因进行了表达分析。结果显示:(1)‘上师大5号’的胚重、胚与糙米质量比均极显著大于‘超2-10’,且‘超2-10’的胚重接近或大于一些已报道的巨胚水稻;(2)‘上师大5号’巨胚表型由1对隐性基因控制,并与韩国巨胚稻‘M-2-565-11-3-B(ge)’属于相同的等位基因突变;(3)‘超2-10’、‘上师大5号’和‘M-2-565-11-3-B(ge)’3种水稻各自具有1个新的GE等位基因,它们的突变位点分别位于启动子、启动子及编码链、编码链;(4)‘上师大5号’启动子及编码链都有突变的GE等位基因(gec),在开花后4~7d的颖果中表达量持续增加,完全不同于只有编码链突变的GE等位基因呈持续下降的表达模式。该研究首次报道了突变在启动子、突变同时发生在启动子及编码链2种新型巨胚等位基因。     

阿霉素脂质体的制备及其体外抗肿瘤活性的初步研究

目的:应用超声波分散法制备脂质体阿霉素,并比较脂质体阿霉素与游离性阿霉素抗肿瘤活性。方法:以卵磷脂和胆固醇为原料,将阿霉素包封于脂质体中,采用超声分散法制备脂质体阿霉素,对其在290-700nm范围内进行紫外扫描,用SephedexG-50柱分离脂质体阿霉素并计算其包封率。以昆明种小鼠为载体建立肿瘤模型(S180型肉瘤)和细胞荧光染色法研究脂质体阿霉素的抗肿瘤活性,以ZITA SIZER3000型表面电位与粒度测定仪测定其粒径分布。结果:脂质体阿霉素在480nm处有最大吸收峰值,包封率达91.3%,细胞荧光染色显示,脂质体及游离型阿霉素均对S180细胞有明显的抑制作用。结论:此法制备的脂质体阿霉素包封率高,粒径分布集中,脂质体阿霉素较游离型阿霉素有较强的抗肿瘤活性剂及较低的细胞毒作用,对阿霉素的临床应用有一定的参考价值。     

URI基因稳定表达对肝癌SMMC-7721细胞增殖能力的影响

目的:瞬转以及筛选出能够稳定表达URI(RPB5-mediating protein)基因的SMMC-7721细胞株,以其为模型研究URI基因对人肝癌SMMC-7721细胞增殖的影响.方法:首先,抽提URI的重组质粒并转染到SMMC-7721细胞中,在G418药物的筛选下选出能够稳定表达URI基因的细胞株,RT-PCR法和酶切检测该稳定细胞中URI基因的表达效率以确认URI是否稳定表达,MTT法和克隆形成实验检测URI基因对SMMC-7721细胞增殖的影响.结果:成功建立URI基因过表达的稳定细胞株.与SMMC-7721细胞对照组比较,其URI mRNA表达水平显著上调,能稳定表达URI细胞株的增殖,克隆形成率明显升高.结论:pFLAG-CMV-4-URI重组质粒能使URI在肝癌SMMC-7721细胞内稳定表达,过表达URI基因有可能帮助细胞通过G2/M期检验点来提高肝癌细胞SMMC-7721的增殖能力.