Gene delivery to glioma cells in rat brain by grafting of a retrovirus packaging cell line

Retrovirus vectors only integrate into the genome of dividing cells and can thus be used to selectively infect tumor cells in the adult rat brain. Gene delivery was assessed by using the retrovirus BAG vector, which bears the Escherichia coli lacZ gene under the MoMLV LTR promoter-enhancer element, and by histochemical staining for bacterial beta-galactosidase activity. Direct injection of this vector (90-900 cfu) into the adult rat brain, with or without prior inoculation of C6 glioma cells (2 x 10(5) cells) resulted in labeling of only a few cells as assessed 1 week later. When the psi 2-BAG packaging line was grafted into the brain, labeled psi 2-BAG cells could be found after 1 day, but not after 5 days, following grafting, suggesting that the grafted cells had been rejected and that no endogenous cells had integrated released vector, or that expression of lacZ had been turned off. In contrast, when the psi 2-BAG packaging line was grafted into a brain region, which had been inoculated previously with rat C6 glioma cells (2 x 10(5) cells), beta-galactosidase labeling of these tumor cells, identified by immunocytochemistry for glial fibrillary acidic protein and S100, could be demonstrated 10 days later. Thus, grafting of retrovirus packaging lines into adult brain provides a mean to infect tumor cells in situ. The grafted packaging cells may continue to release retrovirus particles for an extended period, thus infecting more cells at the stage of division appropriate for viral integration, as compared to inoculation of the virus alone. Grafting of retrovirus packaging cell lines could be used to selectively deliver "killer" or "suppressor" genes to tumor cells in the brain to curtail their growth.     

含不同启动子的腺病毒载体介导的人β2肾上腺素能受体基因在心肌细胞的表达

目的：观察不同的启动因子cmv,mlc-2v对腺病毒载体介导的人β2肾上腺素能受体（β2－AR）基因在大鼠心肌细胞中表达,方法：分别构建cmv,mlc-2v启动子并携带人β20－AR基因的重组腺病毒Adcmvβ2AR,Admlc,β2AR,用以感染心肌细胞,并检测心肌细胞对人β2－AR基因的表达及cAMP的含量,结果：经RT－PCR,Western免疫印迹分析证帝感染的心肌细胞均表达人β2－AR,放射性配基检测显示含mlc-2v启动子Admlcβ2AR感染的心肌细胞β2－AR密度低于含cmv启动子的A β2AR感染组（P＜0．01）,经10umol/L异丙肾上腺素作用,感染组的心肌细胞内cAMP含量明显高于对照组,感染组间存在明显差异（P＜0．01）,结论：含不同启动子的腺病毒载休感染心肌细胞后均可表达具有生物活性的人β2－AR,但两者存在差异。     

云南省金平县蚊虫及其与流行性乙型脑炎病毒关系的调查

1990年8月在金平县捕获成蚊4属18种5654只,其中库蚊9种、按蚊7种、伊蚊1种、阿蚊1种。中华按蚊、伪杂鳞库蚊和三带喙库蚊为优势蚊种。该县人群血清中乙型脑炎病毒抗体阳性率为21.33％(16/75)。三带喙库蚊和伪杂鳞库蚊可能是当地乙型脑炎病毒的传播媒介。     

云南省昆明机场蚊虫调查报告

1997年5月至1998年4月,在昆明机场捕获蚊虫2366只,经鉴定计有6种。其中致倦库蚊为该机场的优势蚊种,占69.06％,且夜间活动持续时间长;其密度高峰出现在5至7月。     

云南省盈江县蚊虫调查及乙型脑炎病毒分离

1984年及1989年7～8月,在盈江县捕获成年雌性蚊虫7属32种632O只,霜背库蚊、三带喙库蚊和棕头库蚊是农村畜圈的主要蚊种,伪白纹伊蚊和白纹伊蚊是野外竹林区的优势蚊种。对所获蚊虫用C6/36细胞和小白鼠方法分离病毒,从三带喙库蚊和窄翅伊蚊中各分离到1株乙型脑炎病毒。分析认为三带喙库蚊是当地乙型脑淡病毒的主要传播媒介,窄翅伊蚊亦可参与该病毒的传播。     

AFP启动子调控PNP载体的构建及分析

目的分别构建三种启动子调控的大肠杆菌嘌呤核苷磷酸化酶(PNP)基因表达载体,检测、分析三者的表达差异.方法构建三种启动子调控的PNP基因表达载体.将三个PNP基因载体转染不同细胞株,检测PNP基因在各细胞株中表达,分析三者表达的特点.结果AF 0.3和[HRE]AF调控的PNP基因在AFP阳性肝癌细胞中实现了靶向性表达,而且后者在AFP阴性肝癌细胞中也实现了靶向性表达.结论三种PNP基因表达载体的成功构建为利用PNP/MeP-dR系统进行肝癌的靶向性基因治疗打下坚实的基础.     

大蒜膏与花露水治疗蚊虫叮咬疗效观察

目的：观察大蒜膏与花露水用于蚊虫叮咬患者治疗效果的差异性。方法：选取蚊虫叮咬症状明显的患者967人,随机分为花露水治疗组（A组）和大蒜膏治疗组（B组）。观察两组患者蚊虫叮咬后红肿、瘁痛在72h内缓解的时间,对比两组治疗蚊虫叮咬的差异。结果：蚊虫叮咬的患者在72h之内红肿、痒痛症状缓解情况,A组和B组比较有显著性差异（P〈0．001）。结论：大蒜膏用于治疗蚊虫叮咬治疗效果好,无毒副作用。     

A novel polymer-lipid hybrid nanoparticle for efficient nonviral gene delivery

Aim:

To develop a novel non-viral vector with high transfection efficiency and low cytotoxicity.

Methods:

Poly (ethylene glycol)-distearoylphosphatidylethanolamine (PEG-DSPE) was incorporated into polymer-lipid hybrid nanoparticles (PLN) to construct a PEG-DSPE modified long circulating PLN (L-PLN). The L-PLN was prepared by the emulsifying-solvent evaporation method, L-PLN and L-PLN/DNA complexes were characterized. Both HEK293 and MDA-MB-231 cells transfected by L-PLN/DNA complexes were observed under a fluorescence microscope. The transfection efficiency of the complexes to HEK293 cells was further evaluated by flow cytometry.

Results:

The GFP fluorescence intensity in HEK293 cells transfected by the L-PLN/DNA complexes (N/P=10) was about 37.2%, which was higher than those transfected by PLN alone or commercial Lipofectamine^TM 2000. The L-PLN exhibited minimal toxicity at a low N/P ratio compared with other vectors.

Conclusion:

L-PLN as a novel gene delivery system, has higher transfection efficiency and acceptable cytotoxicity compared to the corresponding PLN, which is beneficial for the development of non-viral gene transfer vectors and may offer an alternative strategy for the future gene therapy.     

腺病毒载体在病毒性疫苗中的研究进展

基于腺病毒载体安全性好、诱导体液和细胞免疫效率高、容纳外源基因片段大、易于大规模培养等优点,其为构建新型疫苗提供了新的思路与手段.此文简要综述了腺病毒的生物学特性、腺病毒载体的构建策略、以腺病毒为载体构建病毒性疫苗的研究现状和目前存在的问题等,重点介绍了已经进入临床试验的腺病毒载体病毒性疫苗的研究进展.