Requirements for effective malaria control with homing endonuclease genes

Malaria continues to impose a substantial burden on human health. We have previously proposed that biological approaches to control the mosquito vector of disease could be developed using homing endonuclease genes (HEGs), a class of selfish or parasitic gene that exists naturally in many microbes. Recent lab studies have demonstrated that HEGs can function in mosquitoes. We constructed and analyzed a model of mosquito population genetics and malaria epidemiology to determine how well HEGs need to function in order to have a significant effect on the burden of disease. Our model, combined with currently available data, indicates that populations of Anopheles gambiae could be eliminated by releasing 2-3 HEGs targeting female fertility genes, or a driving-Y chromosome that is transmitted to 75-96% of progeny. Combinations of fertility-targeting HEGs and Y drive may also be effective. It is possible to eliminate the disease without eliminating the vector, but the parameter space producing this outcome appears to be small. HEGs causing a quantitative reduction in adult survival can be more effective than those targeting female fertility, but the selection coefficients that need to be imposed are still large, unless many HEGs are to be released. Simulations show that HEG-based strategies can be effective over socially relevant time frames. Important limiting assumptions of the models are that there is only a single vector species, and we model a homogeneous population, not a landscape. Nevertheless, we conclude that HEG-based approaches could have a transformational effect on malaria control efforts.     

GDF5基因启动子表达载体的构建

目的构建含人生长分化因子5（GDF5）基因启动子表达载体pGL3-GDF5,为研究GDF5在骨骼、肌肉发育的作用机制提供实验基础。方法扩增人GDF5基因启动子序列,克隆至pGL3-Basic表达载体并转化入大肠杆菌DH10b,双酶切鉴定并测序。结果 PCR扩增后的产物在约854 bp处出现明显的特异性条带,酶切鉴定结果与理论预测值一致,测序未出现碱基突变。结论成功构建了含GDF5基因启动子的表达载体。     

Regeneration of axons in injured spinal cord by activation of bone morphogenetic protein/Smad1 signaling pathway in adult neurons

Axon growth potential is highest in young neurons but diminishes with age, thus becoming a significant obstacle to axonal regeneration after injury in maturity. The mechanism for the decline is incompletely understood, and no effective clinical treatment is available to rekindle innate growth capability. Here, we show that Smad1-dependent bone morphogenetic protein (BMP) signaling is developmentally regulated and governs axonal growth in dorsal root ganglion (DRG) neurons. Down-regulation of the pathway contributes to the age-related decline of the axon growth potential. Reactivating Smad1 selectively in adult DRG neurons results in sensory axon regeneration in a mouse model of spinal cord injury (SCI). Smad1 signaling can be effectively manipulated by an adeno-associated virus (AAV) vector encoding BMP4 delivered by a clinically applicable and minimally invasive technique, an approach devoid of unwanted abnormalities in mechanosensation or pain perception. Importantly, transected axons are able to regenerate even when the AAV treatment is delivered after SCI, thus mimicking a clinically relevant scenario. Together, our results identify a therapeutic target to promote axonal regeneration after SCI.     

四环素调控复制缺陷性疱疹病毒载体介导LacZ基因在原代培养神经元中的表达

目的利用四环素调控复制缺陷性单纯疱疹病毒I型重组载体(QR9TO-LacZ)感染体外原代培养的大鼠皮层神经元,探讨其介导半乳糖苷酶(LacZ)基因的表达情况及基因调控效能;并检测该载体对神经元活力的影响。方法用RUL9-8细胞系扩增QR9TO-LacZ病毒株,收集后采用噬斑法测定病毒滴度;体外原代培养大鼠皮层神经元。将培养的原代神经元分为强力霉素(DOX)组和对照组。两组细胞均用QR9TO-LacZ转染,强力霉素组加入四环素衍生物强力霉素(0.5μg/ml),对照组加入等剂量空白对照液。同时根据感染复数(MOI),即MOI=3、5、10、30 PFU/cell,将两组培养细胞进一步分为亚组。病毒转染48h后行X-gal染色;光镜下观察神经元形态,随机选取10个高倍镜视野(×400),计算每高倍镜视野中平均蓝染细胞率,比较不同MOI病毒感染神经元的效率。采用四甲基偶氮唑盐微量酶反应比色法(MTT法)检测感染病毒48 h(MOI同上)后神经元的活性。结果在含有DOX的培养环境中,不同MOI亚组(3、5、10、30 PFU/cell)QR9TO-LacZ感染神经元出现蓝染细胞百分比分别为5.35%±0.84%、10.64%±1.92%、19.73%±2.87%、34.41%±2.58%;在无DOX的培养环境中,各亚组均未观察到蓝染细胞。上述MOI感染的神经元细胞存活率分别为:90.24%±8.16%、88.00%±5.69%、83.95%±3.82%、78.90%±5.49%。结论 QR9TO-LacZ载体能有效地将目的基因导入原代培养神经元中并表达;目的基因表达的开启受强力霉素调控;QR9TO-LacZ对体外原代培养神经元毒性较低。     

虫媒病毒及其媒介蚊虫microRNA的研究现状和展望

目前,虫媒病毒引起的严重传染病在世界范围内流行.有关虫媒病毒与媒介蚊虫间相互作用关系成为研究的热点.随着microRNA在动物、植物,甚至是病毒中的发现,使得虫媒病毒与蚊媒之间复杂的分子作用关系有了新的研究视野.本文主要综述虫媒病毒与其媒介蚊虫在microRNA水平上的相关研究进展.     

基于MR图像三维纹理特征的阿尔茨海默病和轻度认知障碍的分类

目的 利用三维纹理特征对阿尔茨海默病(AD)患者和轻度认知障碍(MCI)患者进行分类识别,以探索AD早期诊断新途径。方法 对12例早期AD患者(AD组)、12例MCI患者(MCI组)及12名健康对照者(NC组)的MR图像进行三维纹理分析,采用灰度共生矩阵和游程长矩阵提取每位受试者左、右侧海马结构及胼胝体的三维纹理特征,选取三组间存在显著性差异的纹理参数作为特征变量,采用支持向量机(SVM)方法对各组进行分类,利用留一法估算分类准确率。结果 对NC组与MCI组、MCI组与AD组、NC组与AD组进行分类识别的最高准确率分别为79.17%、83.33%、91.67%。结论 利用三维纹理分析可分类识别早期AD患者及MCI患者,有助于AD的早期诊断。     

超声速度向量成像技术评价胎儿左心发育不良综合征右心室功能

目的 运用超声速度向量成像技术(VVI)评估胎儿左心发育不良综合征(HLHS)右心室功能,探讨其临床意义。 方法 Ⅰ组为56胎HLHS胎儿:分为Ⅰa组(心室腔狭小,30胎)和Ⅰb组(心室腔不可见,26胎),Ⅱ组为147胎正常胎儿(正常对照组)。通过Syngo US Workplace VVI工作站处理胎儿标准四腔心二维动态图,获得右心室心肌的运动参数,包括应变(S)、收缩期应变率(SRs)、舒张期应变率(SRd)、收缩期达峰速度(Vs)、舒张期达峰速度(Vd)。 结果 Ⅰ组与对照组比较,右心室心肌各参数差异有统计学意义(P<0.05);Ⅰa和Ⅰb组比较,右心室心肌各参数差异无统计学意义(P>0.05);Ⅰ组Vs与孕周呈正相关(r=0.835,P<0.05),Vd与孕周无显著相关性(r=0.013,P>0.05)。 结论 HLHS胎儿右心室收缩功能增强,舒张功能受损,孕中晚期Vs随孕周增加的程度高于正常胎儿。VVI为探讨胎儿心肌发育的生理及病理学机制提供了一种新的方法。     

速度向量成像技术评价病毒性心肌炎患者左心室扭转运动

目的 探讨采用速度向量成像(VVI)技术定量评价病毒性心肌炎(VMC)患者左心室扭转运动的临床价值。 方法 对27例VMC患者(VMC组)及27名正常人(正常对照组)进行常规超声心动图检查并采集左心室短轴切面图像后,使用VVI技术分析左心室扭转运动参数,并检测所有受试者血浆氮末端脑钠素前体(NT-proBNP)的含量,分析VMC患者左心室扭转参数的变化与血浆NT-proBNP浓度变化的相关性。 结果 VMC患者左心室扭转参数均小于正常对照组(P均<0.05),且扭转角度和速度下降程度与射血分数的改变具有较好的相关性;VMC患者左心室扭转参数的变化与其血浆NT-proBNP浓度测值呈负相关。 结论 VMC患者左心室扭转运动变化与心功能及血浆NT-proBNP的变化明显相关。测量扭转运动参数可为临床评定VMC患者心功能、指导治疗及判断预后提供重要信息。     

基于可见反射光谱法的中医舌诊定量与归类分析研究

目的：应用可见反射光谱方法对舌尖舌质的舌象进行数据采集,探讨中医舌诊对舌质淡白色、淡红色、红色、绛色的定量与归类方法。方法：由舌尖的可见光反射光谱数据计算反演出98位测试对象的舌尖色品坐标及色分布,依据舌尖舌色主要受红光波段能量分布影响的特征,对590～780nm红光范围舌象光谱进行舌尖舌色的计量与分类研究。结果：舌尖舌色数据计算反演于CIE1931色度图,有利于形象地比较不同样本之间的差异性;舌质的可见光反射光谱归一化后,有利于样本间数据的比较与分析;通过670nm光谱能量强度与590～780nm红色色域光谱能量比实现了舌质舌色的量化,并与临床的舌质淡白色、淡红色、红色、绛色有很好的对应准确率。结论：采用可见反射光谱法采集舌象建立的两种舌质舌色中针对红色的量化方法可以根据量化值的差异进行不同舌象变化的区域划分,为中医舌诊的客观化提供有益的参考