白介素-6对NMDA诱导的小脑神经元放电活动的抑制作用及其机制

目的：观察白介素-6（IL-6）对N-甲基-D-天冬氨酸（NMDA）激发的神经元放电活动的影响及其可能的作用机制。方法：用含IL-6、NMDA和JAK抑制剂ACA90的人工脑脊液（ACSF）灌流小脑脑片,利用离体脑片神经元单位放电细胞外记录技术,记录药物对小脑间位核神经元放电的影响。用Western blot法测定间位核神经元NMDA受体亚单位1（NRI）的磷酸化水平。结果：单独用12．5μmol／L和25μmol／LNMDA灌流,神经元放电频率均较基础放电频率增加;用不同浓度IL-6（50,100,200μg／ml）联合NMDA作用后,神经尤的放电频率出现浓度依赖性地降低;AG490可部分阻断IL-6对NMDA兴奋神经元放电的抑制作用。与单独NMDA处理组比较,用IL-6联合NMDA处理神经元后,神经元的NR1磷酸化水平出现浓度依赖性地降低。AG490可阻断IL-6所致的神经元NR1磷酸化水平的降低。结论：IL-6可抑制NMDA激发的小脑间位核神经元的放电兴奋活动;并同时下调神经元的NR1磷酸化水平。     

Specific targeting of nasopharyngeal carcinoma cell line CNE1 by C225-conjugated ultrasmall superparamagnetic iron oxide particles with magnetic resonance imaging

An accurate definition of clinical target volume (CTV) is essential for the application of radiotherapy in nasopharyngeal carcinoma (NPC) treatment. A novel epidermal growth factor receptor (EGFR)-targeting contrast agent (C225-USPIO) was designed by conjugating ultrasmall superparamagnetic iron oxide (USPIO) nanoparticles with cetuximab (C225), to non-invasively define the CTV of tumor. The immunobinding activity of C225-USPIO to NPC cell line CNE1 was confirmed by flow cytometry and immunofluorescence. The time-dependent accumulation of C225-USPIO in CNE1 cells was evaluated using Prussian blue staining. Targeted internalization and subcellular localization of C225-USPIO was confirmed by transmission electron microscope. The results indicated that C225-USPIO specifically bound to EGFR on the surface of CNE1 cells and was taken up into the cell. The uptake of C225-USPIO by CNE1 cells increased significantly with time, when compared with human IgG-USPIO. In addition, 4.7 T magnetic resonance imaging (MRI) revealed that C225-USPIO had a capacity to accumulate in the CNE1 cells, with a resultant marked decrease in MRI T2-weighted signal intensity over time. These findings imply that C225-USPIO has the potential as an MRI contrast agent and can be employed to non-invasively detect early-stage NPC with EGFR overexpression. This provides sufficient theoretical basis for commencing in vivo experiments with the compound.     

鹅细小病毒结构蛋白B细胞线性抗原表位的鉴定

为了对鹅细小病毒结构蛋白B细胞线性抗原表位进行进一步定位,设计了16个覆盖结构蛋白各抗原表位区的长约30个氨基酸残基的重叠短肽,并进行了融合表达。用攻毒10周龄鹅血清对这16个融合蛋白进行蛋白质印迹分析,检测结果表明,VP蛋白线性抗原表位位于35-81、111-161、423-453、462-491、531-577、616-669和678-732氨基酸区域。     

温度对感染沃尔巴克氏体的松毛虫赤眼蜂种群参数的影响

在16℃、20℃、24℃、28℃和32℃恒温下,观察了温度对感染沃尔巴克氏体的松毛虫赤眼蜂发育、存活和繁殖的影响,组建了相应温度下的实验种群生命表。结果表明,在实验温度范围内,感染沃尔巴克氏体的松毛虫赤眼蜂的发育历期随着温度的升高而逐渐缩短,5个温度下感染沃尔巴克氏体的松毛虫赤眼蜂世代的发育历期分别为23.2、17.8、13.2、11.1和7.8天,世代的发育起点温度和有效积温分别为7.40℃和212.69日·度,内禀增长率(r_m)和净生殖力(R₀)分别介于0.2448～0.4584和28.00～84.03之间。结果提示温度24℃～28℃为繁殖感染沃尔巴克氏体的松毛虫赤眼蜂的理想温度条件。     

华南植物区系的评论（三） Ⅳ．旋花科一些种类的修订

作者编写《广东植物志》旋花科时,对据本科的花粉形态特征划分族和属的意义予肯定并采用之;现将其中４个属、６个分类单位的分类或其分布等予于报道．对华南和北越的心萼薯属植物作修订;论证本地区不产ＡｎｉｓｅｉａＣｈｏｉｓｙ．被认为该属的狭花心萼薯Ａ．ｓｔｅｎａｎｔｈｏ和大花心萼薯Ａ．ｓｔｅｎａｎｔｈａｖａｒ．ｍａｃｒｏｓｒｅｐｈａｎａ均是龙骨萼牵牛Ｉｐｏｍｏｅａａｔｅｎａｎｔｈａ;心萼薯Ａｎｉｓｅｉａｂｉｆｌｏｒａ是毛牵牛Ａｎｉｓｅｉａｓｉｎｅｎｓｉｓ;云南土丁桂Ｅｖｏｌｖｕｌｕｓｙｕｎｎａｎｅｎｓｉｓ作新异名处理．应为我国新纪录的归化种（美洲土丁桂Ｅ．ｎｕｍｍｕｌａｒｉｕｓ）;裂叶鳞蕊藤Ｌｅｐｉｓｔｅｍｏｎｌｏｂａｔｕｍ为越南新纪录．也分布于我国江西、海南;海滩牵牛Ｉｐｏｍｏｅｏｓｔｏｌｏｎｉｆｅｒａ这个开白花的海滩植物是一种中草药;虎脚牵牛Ｉｐｏｍｏｅａｐｅｓ－ｔｉｇｒｉｄｉｓ是亚洲和非洲东部热带的广布种,广东大陆西部也有;它是ＩｐｏｍｏｅａＬｉｎｎ．选模式种;这属的中名,本文恢复《广州植物志》（１９５６）等采用的牵牛属,会比较确切用“番薯属”为这个属的中名。     

靶向M细胞的抗原递送¾¾增强黏膜免疫应答的关键策略

黏膜是阻止病原入侵的第一道防线,黏膜免疫系统在抵抗感染方面起着至关重要的作用。通过黏膜途径接种疫苗可以同时诱导黏膜和全身免疫反应,因此,理论上针对黏膜的免疫策略是最合理和有效的。但黏膜免疫系统的复杂性和屏障作用造成抗原诱导的免疫应答水平低下,制约了黏膜疫苗的发展。M细胞(Microfoldcells)是黏膜免疫系统所独有的,其具有捕获腔内抗原和启动抗原特异性免疫应答的功能。M细胞摄取抗原的多少直接关系到黏膜疫苗的免疫效力,而利用M细胞配体可将抗原靶向递呈给M细胞,从而实现高效的黏膜免疫应答。靶向M细胞的抗原递送策略及其应用可以提高黏膜免疫应答水平,促进黏膜疫苗的研制。尽管如此,要成功研制安全高效的黏膜疫苗,今后依然有漫长的路要走,这可能有赖于进一步探究M细胞的特性和功能及黏膜免疫机制。     

Host diversity and behavior determine patterns of interspecies transmission and geographic diffusion of avian influenza A subtypes among North American wild reservoir species

Wild birds can carry avian influenza viruses (AIV), including those with pandemic or panzootic potential, long distances. Even though AIV has a broad host range, few studies account for host diversity when estimating AIV spread. We analyzed AIV genomic sequences from North American wild birds, including 303 newly sequenced isolates, to estimate interspecies and geographic viral transition patterns among multiple co-circulating subtypes. Our results show high transition rates within Anseriformes and Charadriiformes, but limited transitions between these orders. Patterns of transition between species were positively associated with breeding habitat range overlap, and negatively associated with host genetic distance. Distance between regions (negative correlation) and summer temperature at origin (positive correlation) were strong predictors of transition between locations. Taken together, this study demonstrates that host diversity and ecology can determine evolutionary processes that underlie AIV natural history and spread. Understanding these processes can provide important insights for effective control of AIV.