结核分枝杆菌Ag85A DNA的克隆与原核表达

抗原85(Ag85)复合体是BCG合成分泌的可刺激机体产生细胞免疫和体液免疫应答。Ag85A是抗原85复合体组成成分之一,可显著刺激细胞免疫功能增强。研究构建了高效表达的pTrcHisB-Ag85A基因重组质粒,并将其转化至大肠埃希菌TOP10中进行重组蛋白的表达,筛选转化物,SDS-PAGE进行蛋白表达的分子量检测,并通过Western Blotting方法,应用抗Ag85A的单克隆抗体进一步确认重组Ag85A蛋白的表达,建立了Ag85A的原核表达体系,为进一步制备出有效的重组Ag85A疫苗奠定基础。     

海绵状的小肠粘膜下层促进成骨样细胞增殖分化

目的:观察人脂肪干细胞(hADSCs)诱导分化的成骨样细胞在海绵状的猪小肠粘膜下层(SIS)表面的生长情况,探讨三维立体海绵状的SIS能否促进成骨样细胞的增殖和分化.方法:采用物理和化学结合的方法将猪近段空肠制备成脱细胞的SIS,再将薄膜状的SIS经液氮低温研磨制成微粒,交联后采用冷冻干燥技术重塑形为海绵状的SIS;原代培养hADSCs,流式术检测表面抗原,诱导其成骨、成软骨、成脂分化并染色鉴定;将诱导的成骨样细胞与海绵状SIS复合培养,扫描电镜观察细胞形态;应用SIS材料浸提液培养成骨样细胞,MTT法检测细胞增殖情况,ALP活度检测成骨分化情况.结果:脱细胞的SIS未见有核物质,海绵状的SIS呈三维立体状,具有大量均匀一致的孔隙;原代培养的hADSCs表达干细胞相关抗原,并可分化为成骨样细胞,茜素红将钙结节染成紫红色.成骨样细胞与海绵状SIS复合培养后,细胞生长旺盛增殖能力强,ALP表达量明显增加.结论:海绵状的SIS具有均匀的三维孔隙,细胞相容性好,能明显促进hADSCs来源的成骨样细胞的增殖及成骨分化,可成为骨组织工程新型的三维立体天然生物衍生材料.     

改良型抗菌肽的研究进展

长期滥用抗生素导致了耐药菌株“超级细菌”的出现,增加了动物、人类健康和环境污染风险．寻找抗生素替代品正成为全球研究热点,抗菌肽因其高效抗菌效果和不同于抗生素的独特作用机制引起了各国研究者的关注,并进行了相关研究．然而抗菌肽的安全性、稳定性、生产成本等问题限制了其生产与应用．为了克服这些不利因素,研究者们对抗菌肽进行了多种方式的改造,产生了模拟型、同源型、杂合型、轭合型、稳定型和固位型等改良型抗菌肽,并有望在畜牧业、食品业、医药业等领域得到广泛的应用．本文主要综述了这些改良型抗菌肽近年来的研究进展．     

西北地区苹果褐斑病数学预测模型建立与分析

依据2001～2010年我国西北苹果主产区的气象数据与苹果褐斑病(Marssonina coronaria)病害发生流行数据,构建了平均气温(T)、相对湿度(Hm)、风速(Ws)及地表温度(St)影响下苹果褐斑病的流行趋势预测模型,并利用多元回归分析方法建立了苹果褐斑病预测模型.结果表明环境因素严重影响苹果褐斑病的发生和流行,苹果褐斑病预测模型为:f(T,Hm,Ws,St)=1.317T+0.002Hm+0.047Ws+0.001St-11.885[f(T,Hm,Ws,St)为病情指数].苹果褐斑病发生的T为14℃～15℃,Hm为45%,Ws为13m/s,St为10℃.大发生条件为T为20℃～23℃,Hm在70%～90%之间,Ws为0m/s～2m/s及St为22°.     

Quantum dots-based double-color imaging of HER2 positive breast cancer invasion

It has been well recognized that human epidermal growth factor receptor 2 (HER2) level in breast cancer (BC) is closely related to the malignant biologic behaviors of the tumor, including invasion and metastasis. Yet, there has been a lack of directly observable evidence to support such notion. Here we report a quantum dots (QDs)-based double-color imaging technique to simultaneously show the HER2 level on BC cells and the type IV collagen in the tumor matrix. In benign breast tumor, the type IV collagen was intact. With the increasing of HER2 expression level, there has been a progressive decrease in type IV collagen around the cancer nest. At HER2 (3+) expression level, there has virtually been a total destruction of type IV collagen. Moreover, HER2 (3+) BC cells also show direct invasion into the blood vessels. This novel imaging method provides direct observable evidence to support the theory that the HER2 expression level is directly related to BC invasion.     

VANGUARD1 encodes a pectin methylesterase that enhances pollen tube growth in the Arabidopsis style and transmitting tract

In flowering plants, penetration of the pollen tube through stigma, style, and transmitting tract is essential for delivery of sperm nuclei to the egg cells embedded deeply within female tissues. Despite its importance in plant reproduction, little is known about the underlying molecular mechanisms that regulate the navigation of the pollen tube through the stigma, style, and transmitting tract. Here, we report the identification and characterization of an Arabidopsis thaliana gene, VANGUARD1 (VGD1) that encodes a pectin methylesterase (PME)-homologous protein of 595 amino acids and is required for enhancing the growth of pollen tubes in the style and transmitting tract tissues. VGD1 was expressed specifically in pollen grain and the pollen tube. The VGD1 protein was distributed throughout the pollen grain and pollen tube, including the plasma membrane and cell wall. Functional interruption of VGD1 reduced PME activity in the pollen to 82% of the wild type and greatly retarded the growth of the pollen tube in the style and transmitting tract, resulting in a significant reduction of male fertility. In addition, the vgd1 pollen tubes were unstable and burst more frequently when germinated and grown on in vitro culture medium, compared with wild-type pollen tubes. Our study suggests that the VGD1 product is required for growth of the pollen tube, possibly via modifying the cell wall and enhancing the interaction of the pollen tube with the female style and transmitting tract tissues.     

Neural differentiation ability of mesenchymal stromal cells from bone marrow and adipose tissue: a comparative study

Background aimsThe characteristics, such as morphologic and phenotypic characteristics and neural transdifferentiation ability, of mesenchymal stromal cells (MSC) derived from different origins have yet to be reported for cases isolated from the same individual.MethodsThe proliferation capacity, secretion ability of neurotrophins (NT) and neural differentiation ability in rat MSC isolated from bone marrow (BMSC) and adipose tissue (ADSC) were compared from the same animal.ResultsThe ADSC had a significantly higher proliferation capacity than BMSC according to cell cycle and cumulative population doubling analyses. The proportion of cells expressing neural markers was greater in differentiated ADSC than in differentiated BMSC. Furthermore, the single neurosphere derived from ADSC showed stronger expansion and differentiation abilities than that derived from BMSC. The findings from Western blot lent further support to the immunocytochemical data. The mRNA and protein levels of nerve growth factor (NGF) and brain-derived growth factor (BDNF) expressed in ADSC were significantly higher than those in BMSC at different stages before and following induction.ConclusionsOur study suggests that the proliferation ability of ADSC is superior to that of BMSC. Furthermore, differentiated ADSC expressed higher percentages of neural markers. As one possible alternative source of BMSC, ADSC may have wide potential for treating central nervous system (CNS) diseases.     

西咪替丁联合潘生丁治疗过敏性紫癜73例疗效分析

目的:探讨西咪替丁联合潘生丁治疗过敏性紫癜的临床疗效.方法:将我院2010年3月～2011年6月收治的共73例过敏性紫癜患儿随机分为两组,实验组37例给予西咪替丁联合潘生丁进行治疗,对照组36例给予地塞米松、泼尼松、维生素C、维生素D、扑尔敏、钙剂治疗,比较两组患者临床疗效及不良反应的发生情况.结果:治疗后,两组患儿总有效率具有差异性(P＜0.05);且实验组患者皮肤紫癜消退时间,腹痛缓解时间,关节疼痛、肿胀缓解时间,血尿消失时间,血便消失时间,住院天数均明显低于对照组,两组相比具有差异性(P＜0.05).西咪替丁联合潘生丁也无明显不良反应.结论:西咪替丁联合潘生丁治疗过敏性紫癜疗效显著,且无严重不良反应发生,使用便利,值得临床广泛推广和使用.     

Combined effect of sCD40L and PI3K siRNA on transplanted tumours growth and microenvironment in nude mice with gastric cancer

The objective of the paper is to investigate the combined effect of sCD40L and phosphatidylinositol 3-kinase (PI3K) siRNA on transplanted tumours growth and microenvironment in nude mice with gastric cancer. 48 h after modeling, the animals were randomly divided into saline + AGS group (A), sCD40L + AGS group (B), saline + PI3K siRNA group (C) and sCD40L + PI3K siRNA group (D), six mice in each group. The mouse in the groups was inoculated with exponential phase AGS cell or PI3K gene silencing cells (100 μl, 5 × 10(6)). After tumour size reaches 0.2-0.3 cm, Tumours in animals of groups were injected with sCD40L (100 μl, 10 mg/kg) or equal volume of saline, thrice each day, respectively. Microvessel density (MVD), apoptosis index, and expression levels of PI3K, Survivin and vascular endothelial growth factor (VEGF) proteins in transplanted tumor cells in gastric cancer nude mice were analyzed by utilizing Immunohistochemistry, western blot, terminal deoxynucleotidyl transferase dUTP nick end labeling assays. Results showed that combination of sCD40L with PI3K siRNA could significantly decrease tumour size, MVD, expression levels of PI3K, Survivin and VEGF proteins, and increase apoptosis index. It can be concluded that combination of sCD40L with PI3K siRNA provides a promising future for gastric cancer therapy.     

Isolation of phenanthrene-degrading bacteria and characterization of phenanthrene metabolites

Three aerobic bacterial consortia GY2, GS3 and GM2 were enriched from polycyclic aromatic hydrocarbon-contaminated soils with water-silicone oil biphasic systems. An aerobic bacterial strain utilizing phenanthrene as the sole carbon and energy source was isolated from bacterial consortium GY2 and identified as Sphingomonas sp. strain GY2B. Within 48 h and at 30°C the strain metabolized 99.1% of phenanthrene (100 mg/l) added to batch culture in mineral salts medium and the cell number increased by about 40-fold. Three metabolites 1-hydroxy-2-naphthoic acid, 1-naphthol and salicylic acid, were identified by gas chromatographic mass spectrometry and UV–visible spectroscopy analysis. A degradation pathway was proposed based on the identified metabolites. In addition to phenanthrene, strain GY2B could use other aromatic compounds such as naphthalene, 2-naphthol, salicylic acid, catechol, phenol, benzene and toluene as a sole source of carbon and energy.