Influence of murine cytomegalovirus infection on the differentiation and the differentiation genes expression in neural stem cells

AIM: The influence of MCMV infection on differentiation and differentiation gene expression in neural stem cells(NSCs) in vitro were investigated for studying the mechanisms of brain abnormalities caused by congenital cytomegalovirus infection.METHODS: NSCs were separated from fetal BALB/C mouse, and cultured and identified in vitro. The differentiation potency of NSCs was observed by immunofluorescence. The NSCs infected by MCMV at dosage of MOI(multiplicity of infection) equaled to 5, 1 and 0.1,respectively, were cultured in differentiation medium. The morphological changes of infected cells were observed under inverted microscope. The ratios of NSCs and its differentiated cells were detected by flow cytometry. The expressions of nestin, GFAP and NSE, markers of NSCs and its differentiated cells, were studied by immunofluorescence(MOI=1). The expression of early antigen(EA) of MCMV was detected to observe the infection process. Real-time RT-PCR method was employed to measure the expression levels of the key genes Neurog2, Myc and Ccnd1 in Wnt signal pathway of NSCs at early stage of differentiation culture.RESULTS: NSCs isolated from embryonic mouse brains proliferated to form neurospheres, strongly expressed nestin and differentiated into NF-200 positive neurons or GFAP positive astrocytes. The infected NSCs did not adhere to the wall and appeared differentiation growths, but showed swollen gradually after differentiation culture. The nestin expression in the infected cells downregulated slowly and was higher than that in control groups(P<0.05). The GFAP and NSE expressions of the infected cells were lower than those in control groups(P<0.05). The early antigen(EA) of MCMV was always detected in the cells in infected groups. The ratios of nestin positive cells in infected groups were higher than those in control groups, but the ratios of GFAP and NSE positive cells of former were lower than that of the latter from 3rd to 9th d after differentiation culture(P<0.05). The levels of Neurog2 mRNA and Myc mRNA in infected groups were markedly lower than those in normal control groups on 1st d and from 1st to 4th d after differentiation culture, respectively(P<0.05). The levels of Ccnd1 mRNA of infected groups were obviously lower than those in normal control groups from 12th h to 1st d(P<0.05). These changes in infected groups became more obvious as MCMV MOI increased.CONCLUSION: MCMV significantly inhibits differentiation of NSCs to neurons and astrocytes, and leads to the decrease in differentiated cells. MCMV inhibits or interferes with the gene expression of Neurog2, Myc and Ccnd1 in Wnt signal pathway of NSCs. The effect that MCMV inhibits the expressions of differentiation and the differentiation genes in NSCs shows dose-dependent with MCMV MOI. The inhibitory effect of MCMV on the differentiation of NSCs might be induced by interfering with the expression of differentiation gene in NSCs, which is possibly the one of primary causes of brain development disorders induced by congenital CMV infection.     

不同西瓜类型果实茄红素含量的比较研究

采用分光光度法对33个西瓜材料进行茄红素含量的测定,材料涉及不同的瓤色和倍性。结果表明:在白瓤、橙黄瓤、金黄瓤、粉红瓤、红瓤和深红瓤的西瓜材料之间,白瓤西瓜茄红素含量最低,深红瓤西瓜含量最高,茄红素的含量与瓤色大致成正相关。其中深红瓤二倍体西瓜材料中S292、VS8-44的茄红素含量比较高,分别为6.372 mg/100g鲜重和6.350 mg/100g鲜重,三倍体材料中最高的是VS6-19,茄红素含量为6.684 mg/100g鲜重。同瓤色的不同材料之间茄红素的含量与倍性无关,与材料的基因型相关。     

黄土高原丘陵沟壑区苹果园水肥耦合试验研究

在西北黄土高原丘陵沟壑区选择试验点,开展了苹果园水肥耦合试验,研究内容包括苹果园土壤农化性状测试分析;不同水肥耦合试验组合对土壤养分含量的影响;不同水肥耦合试验组合对苹果树的干周、产量、质量及效益的影响等。试验研究结果证明,实行平衡施肥后,土壤中的养分含量磷素提高到2~3级;氮素保持5级,钾素保持2级,有机质含量均有提高。提出了在苹果树不同树龄段,最适的水肥耦合量比例。按照该水肥耦合比例,能有效提高肥料利用率和土壤养分含量,基本达到了各树龄段的优质果园标准,经济效益显著。     

送春与多花兰杂种的非共生萌发与快速繁殖

用地生兰送春和附生兰多花兰进行种间杂交,对杂交种子进行非共生萌发和快速繁殖研究.结果表明:胚龄7个月、0.1 mol/L KOH处理10 min的种子萌发率最高;种子萌发后原球茎的增殖以Z4 (KC+BA 0.4 mg/L+NAA 0.6 mg/L+KT 0.2 mg/L ) 培养基为最好,增殖系数可达到12.8;在原球茎增殖和分化成苗过程中加入活性碳能够有效地防止切口褐化.     

DWDM技术在电力通信系统中的应用研究

采用DWDM技术是电力通信系统扩容的有效手段.简述系统的概念、原理及系统组成,介绍光放大技术、克服色散技术、光合波与分波技术、光转发技术4种主要的DWDM技术,并分析了系统保护和网络管理的设计思路.     

膜式空气弹簧动态特性有限元分析及试验研究

运用ABAQUS有限元软件仿真分析空气弹簧在不同频率与振幅激励下的动态特性,获得空气弹簧最小刚度频率曲线。通过与试验结果的比较,发现空气弹簧刚度随激励频率有一定变化规律,频率是影响空气弹簧动态力学性能的关键外在因素之一。     

茯苓酸对SLT-Ⅱe诱导的大鼠肠黏膜微血管内皮细胞分泌P-选凝素、sICAM-1及TNF-α的影响

通过检测茯苓酸对SLT-Ⅱe诱导大鼠肠黏膜微血管内皮细胞分泌P-选凝素、sICAM-1及TNF-α的浓度变化,探索茯苓主要成分茯苓酸对仔猪水肿病的疗效机制.将培养的肠黏膜微血管内皮细胞分为对照组、SLT-Ⅱ e组、不同质量浓度茯苓酸处理组5个组,采用ELISA法测定了培养3,6,9,12 h细胞上清液中P-选凝素、sICAM-1及TNF-α浓度的变化.结果表明,不同质量浓度茯苓酸处理组对SLT-Ⅱ e诱导肠黏膜微血管内皮细胞过量分泌P-选凝素、TNF-α无明显的抑制作用;0 mg/L茯苓酸处理组对SLT-Ⅱ e诱导肠黏膜微血管内皮细胞sICAM-1的分泌具有明显的下调作用,使其分泌sICAM-1的浓度逐渐下降至正常水平.由此可见,茯苓酸通过抑制SLT-Ⅱ e诱导肠黏膜微血管内皮细胞sICAM-1的过量分泌,阻止白细胞与内皮细胞之间的牢固黏附,防止过度炎症反应对机体的损害,以达到治疗疾病的目的.茯苓酸保护大鼠肠黏膜微血管内皮细胞损伤的模型剂量为10 mg/L.     

大菱鲆致病性溶藻弧菌SR1的外膜蛋白及其抗原性分析

用十二烷基肌氨酸钠(Sarkosyl)抽提结合超速离心的方法提取了一株大菱鲆致病性溶藻弧菌(Vibrio alginolyticus)SR1和其他7株弧菌的外膜蛋白。通过SDS-PAGE图谱分析比较了这8株弧菌外膜蛋白的组成,结果表明,8株弧菌的外膜蛋白电泳一般可得到6-12条条带,其分子量多集中在65-106 kD和28-48 kD,其中36 kD的蛋白带为8株弧菌所共有。用兔抗SR1全菌血清进行Western-blot印迹显示,菌株SR1的外膜蛋白条带中有6条发生了阳性反应,其分子量分别为73 kD、48 kD4、5 kD3、9 kD、36 kD和32 kD。而其他7株弧菌的外膜蛋白与兔抗SR1血清也发生程度不等的阳性反应,这些阳性反应条带的分子量集中在65-73 kD、45-48 kD和36-41 kD之间,其中36 kD的外膜蛋白在8株弧菌中均出现明显的阳性反应,说明36 kD的外膜蛋白是这8株弧菌共有的特异性抗原。     

数据仓库技术在旅游业中的应用

随着社会经济的快速发展和人民生活水平的不断提高,旅游已经日益成为人们生活和国民经济中的重要组成部分.因此,越来越多的企业管理者开始关注旅游者的消费行为.在竞争激烈的旅游市场中,如何利用大量的历史数据信息,分析挖掘出隐含其中的内在联系,用于辅助管理者制定决策信息是企业急需面对的问题.本文重点介绍了如何构建面向旅游者消费事实的企业数据仓库.     

汽车悬架阻尼匹配研究及减振器设计

为了使车辆满足平顺性要求,对车辆悬架系统阻尼匹配进行了研究,建立了最佳阻尼比设计方法及减振器速度特性分段线性数学模型.以此模型为基础,建立了减振器阎系参数设计数学模型,并对阀系参数进行优化设计.对设计减振器进行了特性试验和整车振动试验,并与原车裁减振器性能进行了对比.结果表明,车辆悬架系统阻尼匹配合理,减振器阀系参数设计方法正确,设计参数值准确、可靠.