人干扰素ω(huIFN-ω)的高效表达、纯化及生物学活性

为了获得人干扰素-ω(huIFN-ω)在大肠杆菌中的高效表达,根据大肠杆菌的偏爱密码子,人工设计并合成了huIFN-ω高表达基因,并克隆到原核表达载体pBV220,在大肠杆菌DH5α中实现了高效表达,目的蛋白占细胞总蛋白的15%左右,以包涵体形式存在.表达产物经变性、复性及阳离子和分子筛层析纯化,纯度达90%以上,产物的抗病毒活性约为1.0×108IU/mg,并具有体外促NK杀伤活性.此结果为进一步研究和开发重组huIFN-ω奠定了基础.     

Avoidable errors in the modelling of outbreaks of emerging pathogens, with special reference to Ebola

As an emergent infectious disease outbreak unfolds, public health response is reliant on information on key epidemiological quantities, such as transmission potential and serial interval. Increasingly, transmission models fit to incidence data are used to estimate these parameters and guide policy. Some widely used modelling practices lead to potentially large errors in parameter estimates and, consequently, errors in model-based forecasts. Even more worryingly, in such situations, confidence in parameter estimates and forecasts can itself be far overestimated, leading to the potential for large errors that mask their own presence. Fortunately, straightforward and computationally inexpensive alternatives exist that avoid these problems. Here, we first use a simulation study to demonstrate potential pitfalls of the standard practice of fitting deterministic models to cumulative incidence data. Next, we demonstrate an alternative based on stochastic models fit to raw data from an early phase of 2014 West Africa Ebola virus disease outbreak. We show not only that bias is thereby reduced, but that uncertainty in estimates and forecasts is better quantified and that, critically, lack of model fit is more readily diagnosed. We conclude with a short list of principles to guide the modelling response to future infectious disease outbreaks.     

新型糖基化酶AlkC和AlkD

DNA糖基化酶是一类有着重要生物功能的蛋白质,广泛存在于原核生物和真核生物中。研究表明,DNA糖基化酶能够特异性地识别损伤碱基,再通过各种酶修复DNA。最近,科学家在筛选土壤中3-甲基腺嘌呤糖基化酶时,发现了三种基因AlkC、AlkD和AlkE,其中AlkC和AlkD是两种新基因。本文根据近年来的研究成果,对AlkC和AlkD两种碱基糖基化修复酶的结构和功能,以及AlkD的切除损伤DNA的核酸捕获机理进行了总结。     

鹰嘴豆种子胰蛋白酶抑制剂的分离纯化与鉴定

为了寻找具有药物作用的天然胰蛋白酶抑制物,采用硫酸铵分级沉淀、离子交换层析(DEAE-纤维素52)及Sephadex G-100凝胶层析等方法, 从鹰嘴豆种子中分离出一种鹰嘴豆胰蛋白酶抑制剂（CPTI）. 研究表明：CPTI对胰蛋白酶有较强的抑制作用,抑制率达80%,而对胰凝乳蛋白酶抑制作用较弱,抑制率为32%, 对胃蛋白酶、木瓜蛋白酶及枯草杆菌蛋白酶均无抑制作用; 用SDS-PAGE测得CPTI近似分子质量为25.7 kD; CPTI具有较高的热稳定性,在100 ℃下加热60 min,对胰蛋白酶活性仍保持78%抑制率; Lineveaer-Burk作图得知该抑制剂属竞争性抑制类型. 动力学测定显示,来自鹰嘴豆中的CPTI对胰蛋白酶的抑制作用常数(Ki)为3.99×10^-7 mol/L.     

生长因子诱导人脐带/胎盘间充质干细胞定向分化

近年来,间充质干细胞(mesenchymal stem cell,MSC)已成为干细胞领域的研究热点,其不仅支持造血系统,还可在特定的培养条件下向多种组织细胞分化。人脐带和胎盘来源的MSC取材容易,较骨髓间充质干细胞有更广泛的应用前景。本文就含有特定生长因子的培养基诱导人脐带MSC和人胎盘MSC定向分化的研究进展作一简要的综述。     

RNA干扰在疾病治疗上的应用

RNA干扰(RNA interference,RNAi)是一种双链RNA分子在mRNA水平上引发的特异性基因沉默现象。RNAi在基因治疗方面表现出了光明的前景,已成功地应用于多种疾病的临床治疗。本文主要介绍了RNAi在疾病治疗上的应用及研究进展。     

Electronic Nose with an Air Sensor Matrix for Detecting Beef Freshness

China is one of the largest meat producing countries in the wodd. With the growing concern for food safety more attention has been paid to meat quality. The application of conventional test methods for meat quality is limited by many factors, and subjectiveness, such as longer time to prepare samples and to test. A sensor matrix was constructed with several separate air sensors, and tests were conducted to detect the freshness of the beef. The results show that the air sensors TGS2610, TGS2600, TGS2611, TGS2620 and TGS2602 made by Tianjin Figaro Electronic Co, Ltd could be used to determine the degree of freshness but TGS2442 is not suitable. This study provides a foundation for designing and making an economical and practical detector for beef freshness.     

日本的农业基因工程研究及其安全管理

农业部基因工程安全管理办公室对日本的基因工程研究状况、转基因工程体的环境安全和转基因食品的安全所采取的政策、措施,以及消费者对转基因产品的态度、政府对国民和科技普及教育等方面情况的了解,对加快我国农业生产、技术发展,加强和提高我国农业基因安全管理的水...     

山葡萄果实发育过程中花色苷和非花色苷酚成分及其含量的变化

以‘双红’山葡萄果实为试材,采用HPLC—MS／MS技术,分析山葡萄果实发育过程中果皮中花色苷和非花色苷酚成分及其含量的变化。结果表明,转色期前果皮内没有花色苷积累,随着果实的成熟,花色苷含量逐渐增加,成熟期的含量最高;非花色苷酚自花后2周至成熟期间的含量变化呈下降趋势。在山葡萄果实发育过程中检测出花色苷10种,其中双糖苷5种、单糖苷5种;非花色苷酚类物质检测到14种,其中苯甲酸类2种、肉桂酸类3种、黄烷-3-醇类2种、黄酮醇类5种、白藜芦醇类2种。