Enhancing West Nile virus surveillance, United States

We provide a method for constructing a county-level West Nile virus risk map to serve as an early warning system for human cases. We also demonstrate that mosquito surveillance is a more accurate predictor of human risk than monitoring dead and infected wild birds.     

人GJB2基因错义突变表达载体构建及鉴定

目的构建6种分别携带GJB2基因错义突变A40G、V37I、L90P、L90V、V84L和W44C的真核表达载体,转染HEK293细胞,建立6种错义突变的稳定表达细胞系。方法以野生型Cx26-EGFP融合蛋白质粒为模板,用Stratagene公司定点突变试剂盒构建错义突变表达载体,直接测序鉴定序列正确性,选取含有突变的载体转染HEK293细胞,G418选择性培养2周,流式细胞仪筛选表达阳性细胞,扩增培养形成稳定表达人Cx26突变的HEK293细胞系。培养细胞用4%多聚甲醛固定,鬼笔环肽和4‘,6-二脒基-2-苯基吲哚衬染细胞核,荧光显微镜下检测结果。结果6种突变表达载体经过测序,均含有相应突变,无多余突变出现,转染后均可在细胞间形成缝隙连接,呈现绿色荧光。结论成功构建6种携带GJB2基因错义突变的真核表达载体,为进一步研究错义突变致聋原因奠定了实验基础。     

Malarial vectors in an irrigated rice cultivation area in southern Sri Lanka

Entomological surveys were carried out from March 1998 to December 1999 to study the prevalence, distribution and abundance of malarial vectors in relation to selected environmental factors and potential mosquito breeding sites in irrigation channels in 15 villages in the Lunugamvehera Irrigation and Settlement Project, a malaria-endemic area of southern Sri Lanka. Mosquito collections were made at monthly intervals using four sampling methods. Thirteen anopheline species were collected. Following monsoonal rains, anopheline breeding took place primarily in rainwater accumulations. During the inter-monsoonal period, pools formed in the irrigation system, semi-permanent pools formed as a result of rainfall and permanent ground pools were the major breeding sites of anophelines. Very little anopheline breeding took place within the irrigation channels. Amongst the seven anopheline species collected from human dwellings, Anopheles subpictus was the most prevalent, followed by A. culicifacies; together these two species comprised more than 99% of the indoor resting population. The number of days of rain was an important macro-epidemiological factor influencing the density of malarial vectors. There was no consistent trend between the amount of water released or the number of days of water release from the reservoir and the outdoor or indoor resting densities of anophelines.     

银川市2006-2010年病媒生物监测与防制探讨

目的通过对宁夏银川市兴庆、金凤、西夏3个区开展病媒生物调查,分析银川市2006-2010年鼠、蚊、蝇和蜚蠊的发生动态,为病媒生物防治及其传播疾病的控制提供依据。方法鼠和蜚蠊密度全年监测,分别选择夹夜法和粘蟑纸法调查;成蚊及蝇密度监测时间为5-10月,分别选择人工小时法和笼诱法调查。结果银川市蚊、蝇和蜚蠊密度2006-2010年年际间消长呈单峰型曲线,高峰值出现在2009年,2010年密度均有不同程度下降;鼠类平均密度为0.46%,在每年3-5月和9-10月出现2个高峰,城市以褐家鼠为优势种,农村自然村以小家鼠为优势种;蚊类平均密度为2.87只/人工小时,高峰期在每年的7-8月,优势种为淡色库蚊,占捕获总数的92.90%,中华按蚊、三带喙库蚊构成比逐渐上升;蝇密度高峰期出现在每年的7-9月,家蝇、绿蝇、麻蝇为优势种;蜚蠊平均密度为1.66只/张,平均侵害率17.14%,每年4-6月和9-11月出现2个高峰,德国小蠊为优势种,占捕获总数的91.42%,美洲大蠊构成比逐年上升。结论 2010年银川市对病媒生物的控制有效,但仍需加强病媒生物高峰季节前的控制;褐家鼠、淡色库蚊、家蝇、绿蝇、麻蝇、德国小蠊为银川市优势种,与此相关的传播疾病危险性增强,建议加强对病媒生物及其传播疾病的长期监测、预警、控制对策和措施的研究工作。     

Control of rickettsial diseases

Prevention of rickettsial infections is aimed at individual control and epidemic measures (especially in epidemic typhus), vector and rodent control, milk pasteurization (in Q fever), chemoprophylaxis and immunoprophylaxis. In vector and rodent control, the main obstacle is the rise in resistance to insecticides and rodenticides. For this reason in vector control, apart from insecticides, enhancement of the natural immunity acquired by animals in response to tick infestation and vaccination with concealed tick antigens as well as the use of hormones, chemosterilants and genetic manipulation can also be considered. For short-term high-risk exposure, doxycycline may be an effective prophylaxis of illness but may not prevent infection with scrub typhus or spotted fever group rickettsiae. At present, for specific prevention by vaccination, only Q fever vaccines are available for common use. However, development of subunit vaccines, namely immunogenic rickettsial proteins, cloned and expressed in Escherichia coli, seems to be very promising.Presented at the 4th International Symposium on Rickettsiae and Rickettsial Diseases, Pietany C.S.F.R., 1–6 October, 1990.     

负载PCA3启动子及CD-TK自杀基因腺病毒载体的构建及包装

目的 构建负载PCA3启动子联合CD-TK基因的腺病毒载体,并对其进行包装及滴度测定.方法 将PCA3启动子无缝克隆到pHBAd-U6-GFP上,取代原有U6启动子形成pHBAd-PCA3-GFP,AgeI单酶切该重组载体,将CD-TK基因片段无缝克隆至线性化pH-BAd-PCA3-GFP上,抽提质粒抗性筛选后经PCR及测序鉴定为pHBAd-PCA3-CD-TK载体.取上述重组载体质粒及骨架质粒pHBAd-BHG,用LipofiterTM转染试剂进行转染HEK293细胞包装成病毒,大量扩增并测定病毒感染性滴度.结果 经PCR及测序验证证实成功构建负载PCA3启动子及CD-TK自杀基因的重组腺病毒pHBAd-PCA3-CD-TK并包装扩增,病毒滴度为1×1010PFU/mL.结论 构建负载PCA3启动子及CD-TK自杀基因的重组腺病毒,为进一步体内外对前列腺癌细胞的杀伤效应研究奠定了基础.     

Evolution of parasitism in kinetoplastid flagellates

Kinetoplastid protists offer a unique opportunity for studying the evolution of parasitism. While all their close relatives are either photo- or phagotrophic, a number of kinetoplastid species are facultative or obligatory parasites, supporting a hypothesis that parasitism has emerged within this group of flagellates. In this review we discuss origin and evolution of parasitism in bodonids and trypanosomatids and specific adaptations allowing these protozoa to co-exist with their hosts. We also explore the limits of biodiversity of monoxenous (one host) trypanosomatids and some features distinguishing them from their dixenous (two hosts) relatives.     

幽门螺杆菌热休克蛋白60核酸疫苗的构建和免疫原性鉴定

背景:核酸疫苗是新兴的第三代疫苗。目前幽门螺杆菌(H.pylori)疫苗的研究主要集中在减毒、灭活和亚单位疫苗方面,有关H.pylori核酸疫苗的研究罕见报道。目的:构建含H.pylori热休克蛋白60(hsp60)基因的核酸疫苗,并鉴定其表达蛋白的免疫原性。方法:抽提H.pylori标准菌株CCUG17874基因组DNA为模板,应用聚合酶链反应(PCR)扩增hsp60基因并插入测序载体pUCmT,测定插入的hsp60基因的核苷酸序列。通过一系列酶切、连接反应将hsp60基因克隆入真核表达载体pIRES,然后转化入感受态大肠杆菌DH5α,筛选阳性克隆,行酶切和PCR鉴定。采用脂质体法将所构建的重组载体pIRES鄄hsp60转染真核细胞COS鄄7,蛋白质印迹法(Western blotting)检测pIRES鄄hsp60表达蛋白的免疫原性。结果:以H.pylori基因组DNA为模板,PCR扩增出约1 640 bp的hsp60基因片断,测序结果表明其与GenBank中H.pylorihsp60原序列的同源性达98%。酶切和PCR鉴定结果证实hsp60基因已克隆入真核表达载体pIRES,成功构建了含hsp60基因的H.pylori核酸疫苗pIRES鄄hsp60。蛋白质印迹法检测显示经pIRES鄄hsp60转染的COS鄄7细胞在约60 kDa(1 Da=0.992 1 u)处出现特异性蛋白条带。结论:成功构建了具有免疫原性的含hsp60基因的H.pylori核酸疫苗,为进一步探索其免疫作用奠定了     

小鼠GSK-3β慢病毒表达载体的构建及其在骨髓树突状细胞DC2．4中的表达

目的构建pLVX‐IRES‐TDtomat‐GSK‐3β慢病毒表达载体,感染小鼠骨髓DC2．4细胞,建立过表达GSK‐3β的小鼠DC2．4细胞系。方法利用RT‐PCR方法扩增小鼠GSK‐3β基因的编码区,并将其重组于表达载体pLVX‐IRES‐TDtomat中,经酶切、测序鉴定后包装成慢病毒,感染小鼠DC2．4细胞。实验分3组,分别为DC2．4细胞对照组,空病毒感染组,GSK‐3β慢病毒感染组,用实时荧光定量PCR方法和Western Blotting方法检测各组GSK‐3β的表达水平。结果经酶切和测序鉴定结果证实pLVX‐IRES‐ TDtomat‐GSK‐3β构建成功,并在包装细胞中高水平表达,慢病毒滴度高达1．26×108 TU／mL。GSK‐3β慢病毒感染组的GSK‐3β在mRNA表达水平和蛋白表达水平上均高于DC2．4细胞对照组及空病毒感染组。结论成功构建了表达GSK3β基因的重组慢病毒载体,并可在DC2．4细胞中稳定表达,为后续DC2．4的免疫功能研究奠定了基础。