早产儿生命早期肠道菌群的建立及其相关疾病研究进展

肠道菌群是一个数量庞大且种类复杂的微生物群落, 是人类的“第二基因组”, 同时又是一个被遗忘的“器官”, 参与调控宿主生理及病理过程。随着检测技术的不断提高, 肠道菌群的研究已经成为了热点, 其与各个系统疾病关系的研究也不断深入。生命早期(包括胎儿期和婴幼儿期)是婴幼儿尤其是早产儿肠道菌群定植及演替的主要阶段, 具备动态变化的特征, 且易受多种因素的影响, 主要包括剖宫产、母乳喂养减少和抗生素使用。这些因素可能会扰乱生命早期肠道菌群分布, 进而影响人类宿主近期或远期健康状况。本文就早产儿生命早期肠道菌群的建立、影响因素及其与疾病关系的研究进展作一综述。

     

伪狂犬病病毒闽A株gE基因去信号肽片段在Pichia pastoris中的表达

伪狂犬病病毒囊膜糖蛋白E是一种在伪狂犬病根除计划中具有重要作用的糖蛋白.将伪狂犬病病毒闽A株gE基因去信号肽片段克隆到巴斯德毕赤酵母（Pichia pastoris）表达载体pPICZαA中,获得的重组表达载体pPICZαA-FL电击转化野生型酵母菌SMD1168后,得到多株酵母工程菌SMD1168/pPICZαA-FL.经高浓度Zeocin^TM筛选、表型鉴定、工程菌的诱导表达及表达产物的鉴定,最后得到高效表达gE基因去信号肽片段的酵母工程菌SMD1168/pPICZαA-FL-7.工程菌72 h培养上清的SDS-聚丙烯酰胺凝胶电泳与蛋白质印迹结果显示,gE基因去信号肽片段表达产物大小约为80 ku,比预期的63.8 ku大.凝胶薄层扫描结合Bradford蛋白质总含量测定结果表明,表达产物占工程菌培养上清总蛋白的13.49%,表达量可达11.7 mg/L.间接ELISA结果表明重组表达产物具有良好的抗原性,能够有效地区分伪狂犬病病毒gE标准阳性与阴性血清.     

新石器时代人骨遗骸中古代DNA的提取及X—Y染色体同源基因片段的PCR扩增

从中国新石器时代人骨遗骸中提取出古代ＤＮＡ。通过聚合酶链式反应技术扩增得到Ｘ－Ｙ染色体上的单考贝同源基因片段。由于扩增的基因片段长度具有性别多态性,从而为古代人骨和牙齿提供了分子生物学的性别鉴定。     

澳门九澳山海滨群落10种植物盛花期物候对极端气候事件的响应

为探究极端气候事件对植物的影响,对澳门九澳山海滨群落10种植物2012-2017年盛花期物候进行了观察。结果表明,植物的盛花期一般在3-9月,其中有4种植物为5月。2013和2016年早春澳门的极端强降水使植物的盛花期出现了明显的提前或者推迟。9种植物的盛花期与盛花期前0～2个月和上一年的秋冬季的月均温度或月降水存在显著相关性。温度和降水对植物盛花期的影响差异不大,但晚花植物对降水更加敏感。这为澳门和邻近岛屿的生态恢复和园林树种选材提供参考。     

The significance of controlled conditions in lentiviral vector titration and in the use of multiplicity of infection (MOI) for predicting gene transfer events

BACKGROUND: Although lentiviral vectors have been widely used for in vitro and in vivo gene therapy researches, there have been few studies systematically examining various conditions that may affect the determination of the number of viable vector particles in a vector preparation and the use of Multiplicity of Infection (MOI) as a parameter for the prediction of gene transfer events. METHODS: Lentiviral vectors encoding a marker gene were packaged and supernatants concentrated. The number of viable vector particles was determined by in vitro transduction and fluorescent microscopy and FACs analyses. Various factors that may affect the transduction process, such as vector inoculum volume, target cell number and type, vector decay, variable vector - target cell contact and adsorption periods were studied. MOI between 0-32 was assessed on commonly used cell lines as well as a new cell line. RESULTS: We demonstrated that the resulting values of lentiviral vector titre varied with changes of conditions in the transduction process, including inoculum volume of the vector, the type and number of target cells, vector stability and the length of period of the vector adsorption to target cells. Vector inoculum and the number of target cells determine the frequencies of gene transfer event, although not proportionally. Vector exposure time to target cells also influenced transduction results. Varying these parameters resulted in a greater than 50-fold differences in the vector titre from the same vector stock. Commonly used cell lines in vector titration were less sensitive to lentiviral vector-mediated gene transfer than a new cell line, FRL 19. Within 0-32 of MOI used transducing four different cell lines, the higher the MOI applied, the higher the efficiency of gene transfer obtained. CONCLUSION: Several variables in the transduction process affected in in vitro vector titration and resulted in vastly different values from the same vector stock, thus complicating the use of MOI for predicting gene transfer events. Commonly used target cell lines underestimated vector titre. However, within a certain range of MOI, it is possible that, if strictly controlled conditions are observed in the vector titration process, including the use of a sensitive cell line, such as FRL 19 for vector titration, lentivector-mediated gene transfer events could be predicted.     

Effects of N-1-naphthylphthalamic acid on the growth and bud formation of tobacco callus grown in vitro

The effect of N-1 -naphthylphthalamic acid (NPA), indole-3-aceticacid (IAA) and kinetin on callus growth and bud formation wasstudied mainly by a tobacco callus culture method. Callus producedfrom Nicotiana tabacum var. Wisconsin 38 was used as the testplant material. Callus growth on nutrient agar containing 2mg/liter of IAA was promoted by NPA added at a concentrationof 0.5 mg/liter with 0.4 mg/liter of kinetin or by NPA addedat 5 mg/liter in the absence of kinetin. At a high concentrationof 50 mg/liter, however, NPA inhibited growth on the mediumcontaining 2 mg/liter IAA and no kinetin. Kinetin reduced thisNPA inhibition. In the presence of 0.4 mg/liter kinetin and2 mg/liter IAA, when the concentration of NPA was 50 mg/liter,buds were initiated after calluses were grown on the test mediumfor 7 weeks in dim light, but no buds formed when NPA was omittedfrom the above medium. The control of callus growth and bud initiation is based onthe active ratio of auxin (IAA) to cytokinin (kinetin) in themedium and NPA added to the medium can promote or inhibit callusgrowth and induce bud formation. Therefore, it is proposed thatNPA can itself reduce auxin activity or enhance cytokinin activityand hence change the active ratio of the two regulators. NPAmay enhance the activity of cytokinin (here supplied as kinetin)but cannot substitute for it. ¹Present address: Department of Biology, Wisconsin State University,Oshkosh, Wisconsin 54901, U. S. A. (Received March 10, 1969; )     

1株拮抗真菌的生防细菌Xj11的分离与鉴定

从江西省井冈山自然保护区发病毛竹中分离到1株具有明显抑制植物病原真菌活性的生防细菌Xj11。其对小麦赤霉病菌、尖孢镰刀菌、甘蔗节菱孢菌、链格孢菌和炭角菌均有较强的抑制作用。通过形态特征和培养特征观察、生理生化实验及16S rDNA序列系统发育分析,初步鉴定该菌为唐菖蒲伯克霍尔德氏菌,命名为Burkholderia gladioli strain Xj11。     

MC 3T3-E1细胞在纳米羟基磷灰石/壳聚糖复合支架上的增殖和分化

用原位合成纳米羟基磷灰石的方法制备多孔纳米羟基磷灰石/壳聚糖复合支架;在支架上接种MC 3T3-E1细胞,瑞氏染色检测细胞形态,MTT法检测其增殖情况;在诱导培养基中培养30d后,碱性磷酸酶染色比较其分化水平;定量检测细胞的碱性磷酸酶活性;RT-PCR检测成骨相关基因的表达情况。实验结果表明：MC 3T3-E1细胞在纳米级羟基磷灰石/壳聚糖复合支架上粘附铺展良好,其增殖率显著高于培养于纯壳聚糖支架上的细胞。碱性磷酸酶染色表明复合支架上的细胞有较高水平的碱性磷酸酶表达。进一步定量检测细胞的碱性磷酸酶活性,结果说明在复合支架上细胞比纯壳聚糖支架上培养的细胞碱性磷酸酶活性提高了约8倍。此外,骨分化相关特征基因骨桥蛋白OPN在复合支架上培养的细胞中的表达水平也明显高于纯壳聚糖上培养的细胞。分化成熟标志基因骨钙素OC在复合支架上培养的细胞中有表达,但是纯壳聚糖支架上培养的细胞中却未检测到。支架中纳米羟基磷灰石的加入不仅提高了前成骨细胞在复合支架上的增殖,而且还促进了它的分化。纳米羟基磷灰石/壳聚糖复合支架表现出良好的生物相容性和生物活性,是极具前景的骨组织工程支架材料。     

松口蘑深层发酵工艺的研究

对松口蘑深层发酵工艺进行系统研究。通过正交试验初步确定松口蘑适宜的培养基组成 :玉米粉 30g,葡萄糖 1 0g ,豆饼粉 1 0g ,玉米浆 1 0g ,KH₂ PO₄1g ,定容至 1L。适宜发酵条件 :最适生长温度为 2 5℃ ,摇瓶转速为 1 60r/min ,最适pH为 5 0 ,最适接种量为 1 0 % ,装液量 1 2 0mL/ 5 0 0mL摇瓶培养 1 0d ,菌体生物量达 1 2 94g/L。