The Ixodes ricinus tick as a vector of Borrelia burgdorferi in Slovenia

In many parts of Slovenia, the vegetation, climate and animals form an ideal natural environment for the persistence of different tick species. In this study, Ixodes ricinus ticks, the prevalent tick species in our country, are identified as the vectors of Borrelia burgdorferi in Slovenia. Ticks were collected by flagging between May and October 1990. All the ticks collected from different parts of Slovenia were I. ricinus and each one was examined individually. The ticks were tested to determine the presence of B. burgdorferi by indirect immunofluorescent assay. Among the 496 ticks examined for borreliae there were 85 adults and 411 nymphs. Twenty (23.5%) adults and 18 (4.4%) nymphs were found positive for Borreliae. This study discusses the importance of I. ricinus ticks in the role of Lyme borreliosis in Slovenia.     

Viral and bacterial vectors of immunogenes

A recent development in the production of experimental vaccines has been the use of the smallpox vaccine virus (vaccinia virus) as a carrier (vector) of the genes (immunogenes) which code for the protection-inducing proteins (immunogens) of unrelated viruses. The potential of these vector vaccines lies in the hope that such a vaccine would be cheaper, safer and/or more effective than existing vaccines to some pathogens. Vaccinia virus as a vector has attracted most attention to date because: several immunogenes can be inserted into its genome without destroying its infectivity; the immunogens appear to be produced normally; vaccinia virus has been used highly successfully to eradicate smallpox; and it has a wide host-range and thus might find veterinary as well as human medical application. Experimental vaccines, successfully tested in animals, have been prepared using immunogenes from influenza virus, hepatitis B virus and herpes simplex virus. Apathogenic enteric bacteria have some potential as vectors, most probably against enteric pathogens, although the potential of viral vectors is likely to be realized first. Parasitic worms and protozoa devastate millions of people. When the immunogens of these organisms have been identified there will be added impetus to investigate the potential of vector vaccines against these pathogens.     

以肝脏为靶器官的基因治疗时重组腺病毒引起的急性肝炎

目的 研究腺病毒为载体的基因治疗时淋巴细胞在肝组织免疫反应中的作用,探讨免疫抑制疗法在腺病毒载体基因治疗中的可行性。方法 取8只恒河猴,经不同路径输入携带大肠杆菌lacZ基因或荧火虫荧光素酶基因luc的重组腺病毒6只。其中4只进行免疫抑制治疗。将含lacZ的质粒DNA注入2只动物作为对照。用免疫组织化学法检测β2－MG、HAL－DR、CD3、CD4、CD8及CD20。结果 腺病毒介导的基因治疗时肝脏的β2－MG、HLA－DR、CD3、CD4及CD8阳性细胞明显增多。腺病毒载体和转基因均与肝损害有关,表现为一过性,呈轻、中度无黄疸性肝炎。免疫抑制的动物只要处于免疫抑制状态下就没有肝炎的表现,基因表达的时间延长。质粒介导的基因转导效果差,无肝损害及免疫反应。所有动物B淋巴细胞抗原CD20始终阴性。结论 腺病毒介导的基因治疗时肝脏的β2－MG、HLA－DR、CD3、CD4及CD8阳性细胞明显增多,造成轻、中度一过性肝损害。使用免疫抑制药物可避免肝损害的发生并延长基因表达的时间。     

大鼠FasL全长cDNA真核质粒的构建及转染HepG2细胞体外诱导细胞凋亡的作用

目的观察HepG2细胞过表达FasL介导细胞凋亡的作用。方法从大鼠睾丸细胞中扩增出rFasL全长cDNA,亚克隆到T载体中,再克隆到pDC315载体中。转染HepG2细胞后用RT-PCR、Wester blot检测rFasL mRNA和蛋白表达,培养48h后收集细胞计数,进行比较分析。结果 rFasL cDNA序列与其在Genbank中的序列完全一致。rFasL真核表达载体转染HepG2细胞后能表达rFasL mRNA和蛋白;转染pDC315-rFasL的实验组HepG2细胞大量死亡。结论成功克隆了rFasL基因并构建其真核表达载体,证明能有效表达于HepG2中,表达FasL的HepG2细胞通过Fas-FasL结合介导周围及自身表达Fas的HepG2细胞凋亡。     

抗菌肽Defensin真核表达载体的构建及其在中国仓鼠卵巢细胞中的表达

目的 构建家蝇幼虫抗菌肽的真核表达载体,并检测它在中国仓鼠卵巢(CHO)细胞中的表达情况.方法 以pUCm-T/Defensin为模板,设计带His标签特异引物,扩增C-末端融合6×His标签的Defensin基因的cDNA全长编码区序列,将其克隆至pcDNA3.1(+)真核表达载体.经酶切及测序鉴定后,以阳离子脂质体...     

胞嘧啶脱氨酶和血管内皮抑素基因慢病毒载体的构建与鉴定

目的 构建携带胞嘧啶脱氨酶(CD)和血管内皮抑素(ES)基因的慢病毒载体.方法 根据GenBank提供大肠杆菌源CD和ES基因序列设计、合成2个基因并构建与荧光蛋白融合的真核表达载体pEGFP-CD和pDS-RED-ES.酶切和测序鉴定后,将载体瞬时转染HEK293细胞,运用实时PCR检测CD和KS基因表达情况.把载体中基因片段EGFP-CD和DS-RED-ES通过BP/LR重组分别构建慢病毒载体,并利用293FT细胞进行慢病毒的包装.将病毒原液浓缩,并测定病毒滴度.结果 酶切、测序及PCR鉴定证实构建出慢病毒载体pLenti6.3-CD-EGFP和pLenti6.3- ES- Monomer - DsRed.感染293FT细胞后荧光显微镜下观察到GFP和DsRed的表达.浓缩慢病毒滴度分别为2.2× 108 TU/ml和6.5×107 TU/ml.结论 成功构建了CD和ES基因慢病毒载体.     

北京市房山区“7.21”水灾后病媒生物监测

目的了解北京市房山区"7.21"水灾后病媒生物密度情况、水灾对病媒生物密度的影响,为灾后媒介生物性传染病的防控提供依据。方法蚊密度监测采用二氧化碳诱蚊灯法,蝇密度监测采用目测法,鼠密度监测采用鼠夹法。结果房山区"7.21"水灾后平均蝇密度为3.48只/m2,蚊密度为2.05(只/灯·小时),鼠密度为0.42%。蚊密度低于常年监测水平,但差异无统计学意义(t=-1.501,P=0.194),鼠密度低于常年监测水平,差异有统计学意义(t=-3.035,P=0.029)。结论蚊蝇鼠总的密度较低,根据病媒生物的监测结果,指导灾后病媒生物的综合防治,降低媒介生物性传染病的暴发与流行。     

北京市怀柔区雁栖湖生态示范区病媒生物防制模式探讨

目的探索雁栖湖生态示范区病媒生物防制模式。方法对雁栖湖生态示范区病媒生物本底调查结果和雁栖湖地区病媒生物控制保障所面临的风险与挑战进行分析,探讨病媒生物防制模式。结果雁栖湖生态示范区病媒生物防制模式包括5大部分,即示范区病媒生物监测及控制、媒介生物性传染病及突发公共卫生事件监测、监测数据的汇总分析、病媒生物危害风险评估和风险预警及分级管理;5个环节紧密相连,其中病媒生物监测及控制和媒介生物性传染病及突发公共卫生事件监测为并行结构。结论经过1年的实施,证实该防制模式具有可操作性;可总结经验,完善模式,向长效机制方面发展。