人脑星形细胞瘤中p27 kip1 蛋白和增殖细胞核抗原PCNA 表达的变化

目的:研究p27kip1蛋白和增殖细胞核抗原(proliferating cell nuclear antigen,PCNA)在星形细胞瘤中的表达与肿瘤病理分级的关系,探讨p27kip1蛋白在星形细胞瘤演变过程中的意义。方法:SP免疫组化法对64例星形细胞瘤的p27kip1蛋白和PCNA表达进行观察。结果:随着病理级别的升高,p27kip1阳性细胞百分率降低,而PCNA则相反,两者的表达成显著负相关。结论:p27kip1表达的缺失可能与星形细胞瘤的发生发展密切相关,PCNA能较客观地反映肿瘤的恶性程度。     

中国淡水三角属涡虫研究的历史与进展

三角涡虫为扁形动物门涡虫纲的代表动物,在动物的起源与演化中占有重要地位,是研究胚胎发育与细胞分化、去分化的好材料。我国研究基础薄弱,缺乏系统资料,以至于三角涡虫种名在我国曾被错误沿用几十年。本文对我国三角涡虫的种类、分布、研究历史与现状进行了全面概述,以期为我国三角涡虫资源调查与区系分类研究提供全面详实的资料。     

mtCOI PCR-RFLP技术鉴别中国入侵型和土著型烟粉虱种群的有效性分析

烟粉虱Bemisia tabaci (Gennadius)是世界范围内最重要的入侵生物之一,准确地鉴别烟粉虱入侵生物型和土著生物型具有十分重要的现实意义。mtCOI PCR-RFLP技术具有快速、高效的特点,是当前应用最广泛的烟粉虱生物型鉴定技术,但是,不同限制性内切酶为基础的mtCOI PCR-RFLP技术在鉴定我国烟粉虱种群中的有效性仍不明了。本文比较了已报导的5种mtCOI PCR-RFLP技术在鉴别中国烟粉虱种群入侵生物型和土著生物型(B型、Q型,ZHJ1型、ZHJ2型、ZHJ3型)的有效性。结果表明,内切酶AluI不能区分B型和ZHJ2型烟粉虱;内切酶TaqI不能准确区分ZHJ3型和Q型烟粉虱个体;而内切酶VspI不仅不能准确区分ZHJ1型和Q型烟粉虱个体,也不能准确区分B型和ZHJ2型烟粉虱;内切酶MseI和Tru9I则不能有效鉴别上述5种烟粉虱生物型,因此不适宜推广使用。     

转双价基因(Bt+CpTI)棉对棉铃虫中肠羧酸酯酶活性的诱导作用

为了明确棉铃虫Helicoverpa armigera(Hübner)取食转双价基因(Bt+CpTI)棉叶以及取食一段时间转基因棉叶后,再取食常规棉叶,对棉铃虫取食量、体重增长量及中肠羧酸酯酶活性的影响,本研究分别用转双价基因棉叶和常规棉叶饲喂4龄棉铃虫幼虫5 d,比较考察了棉铃虫的取食量、体重增长量及中肠羧酸酯酶的活性;另外分别考察了棉铃虫取食转基因棉叶1 d及3 d后再取食常规棉叶,其中肠羧酸酯酶的变化。结果表明,持续取食常规棉花叶片5 d的棉铃虫,其中肠羧酸酯酶的活性持续升高;而持续取食转基因棉叶5 d的棉铃虫,其中肠羧酸酯酶的活性先升高后降低。取食转基因棉花叶片1 d后,取食常规棉叶的棉铃虫,其中肠羧酸酯酶的活性,随着换取常规棉叶时间的延长,活性逐渐降低;而棉铃虫在取食3 d转基因棉叶后再取食常规棉叶,其中肠羧酸酯酶活性却一直保持较高。可见,棉铃虫在取食转基因棉花后,其羧酸酯酶活性可以被诱导,这应与棉铃虫对转基因棉的抗性及防御性有一定关系。     

Ox-LDL-induced TGF-β1 production in human alveolar epithelial cells: involvement of the Ras/ERK/PLTP pathway

Oxidized-low density lipoprotein (Ox-LDL) has been shown to play an important role in impaired surfactant metabolism and transforming growth factor-β1 (TGF-β1) is a critical mediator in the pathogenesis of acute lung injury (ALI)/acute respiratory distress syndrome (ARDS). In this study, we investigated whether Ox-LDL can induce TGF-β1 protein production, and if so, how it achieves this induction in human alveolar epithelial cells (A549). We show here that Ox-LDL not only caused a dose- and time-dependent up-regulation of TGF-β1 production, but also increased Smad3 phosphorylation, Ras/extracellular signal-regulated kinase (ERK) activity and phospholipid transfer protein (PLTP) expression in A549 cells. The inhibition of Ras/ERK activity with specific inhibitors significantly suppressed Ox-LDL-induced TGF-β1 production, Smad3 phosphorylation and PLTP expression. Furthermore, treatment of cells with PLTP siRNA suppressed both TGF-β1 release and Smad3 activation induced by Ox-LDL, but not the activation of Ras/ERK cascade. Taken together, we provide evidences that induction of TGF-β1 production and Smad3 phosphorylation by Ox-LDL is mediated by Ras/ERK/PLTP pathway in human alveolar epithelial cells.     

Progress on breeding for best-hybridized crossing of meat rabbits

Best-hybridized crossing should ideally result in optimal exploitation of heterosis of lines and capitalize on expressed heterosis. Rabbit breeding is heading in the direction of breeding for best-hybridized crossing of meat rabbits. Most special sire lines are selected for post-weaning average daily gain and marketing weight. Post-weaning growth has a negative and favorable genetic correlation with the feed conversion ratio, which is used in indirect selection for feed conversion ratio. The most common selection criteria for special maternal lines are related to litter size at birth or at weaning. Since the heritability of most reproductive traits is low, we must collect as many individual and relative records as possible in the genetic evaluation of rabbits. The BLUP procedure under an animal repeatability model is the most common procedure used for evaluation of animals in selection programs for special lines of meat rabbits. Direct selection for litter size is less efficient than selection for post-weaning growth, but the estimation of heterosis is generally higher for litter size than that for the post-weaning growth. Evaluation of heterosis could be performed by estimating crossbreeding parameters in the cross or comparing contemporary productivity among purebreds and crossbreds. Here, we reviewed breeding of special lines, exploitation of heterosis of crossbreds, and establishment of crossbreeding system of hybrid meat rabbits and summarized the methodologies of breeding special lines, criteria in selection programs, and the result of heterosis estimates.     

肉兔配套系的选育研究进展

配套系在动物育种中能最大程度地利用品系的杂种优势,以获得最大的经济效益,配套系的选育是今后肉兔遗传改良的发展趋势。肉兔父系以选择平均日增重和上市体重为主,断奶后生长性状一般与料肉比呈有利的负遗传相关,可作为料肉比的间接选择标准。而母系以选择断奶数和产仔数为主。大多数繁殖性状的遗传力较低,在进行遗传评估时应当尽可能全面地收集个体和相关亲缘关系个体的记录。重复观测值动物模型下的BLUP估计是进行肉兔专门化品系选育的主要方法。虽然窝内个体数性状的直接选择效率低于生长性状,但其杂种优势一般高于生长性状。通过计算杂交参数和比较同代杂种与纯种间的生产性能可以进行杂种优势的估计。文章对肉兔专门化品系的选育、杂种优势的利用和良种繁育体系的建立进行了综述,总结了肉兔专门化品系的培育方法,性状选择的标准以及杂种优势的估计结果。     

Multifunction of autophagy-related genes in filamentous fungi

Autophagy (macroautophagy), a highly conserved eukaryotic mechanism, is a non-selective degradation process, helping to maintain a balance between the synthesis, degradation and subsequent recycling of macromolecules to overcome various stress conditions. The term autophagy denotes any cellular process which involves the delivery of cytoplasmic material to the lysosome for degradation. Autophagy, in filamentous fungi plays a critical role during cellular development and pathogenicity. Autophagy, like the mitogen-activated protein (MAP) kinase cascade and nutrient-sensing cyclic AMP (cAMP) pathway, is also an important process for appressorium turgor accumulation in order to penetrate the leaf surface of host plant and destroy the plant defense. Yeast, an autophagy model, has been used to compare the multi-valued functions of ATG (autophagy-related genes) in different filamentous fungi. The autophagy machinery in both yeast and filamentous fungi is controlled by Tor kinase and both contain two distinct phosphatidylinositol 3-kinase complexes. In this review, we focus on the functions of ATG genes during pathogenic development in filamentous fungi.     

Risk Factors for Preterm Birth in Five Maternal and Child Health Hospitals in Beijing

Background

Preterm birth, the birth of an infant prior to 37 completed weeks of gestation, is the leading cause of perinatal morbidity and mortality. Preterm infants are at greater risk of respiratory, gastrointestinal and neurological diseases. Despite significant research in developed countries, little is known about the causes of preterm birth in many developing countries, especially China. This study investigates the association between sciodemographic data, obstetric risk factor, and preterm birth in five Maternal and Child Health hospitals in Beijing, China.

Methods and Findings

A case-control study was conducted on 1391 women with preterm birth (case group) and 1391 women with term delivery (control group), who were interviewed within 48 hours of delivery. Sixteen potential factors were investigated and statistical analysis was performed by univariate analysis and logistic regression analysis. Univariate analysis showed that 14 of the 16 factors were associated with preterm birth. Inter-pregnancy interval and inherited diseases were not risk factors. Logistic regression analysis showed that obesity (odds ratio (OR) = 3.030, 95% confidence interval (CI) 1.166–7.869), stressful life events (OR = 5.535, 95%CI 2.315–13.231), sexual activity (OR = 1.674, 95%CI 1.279–2.191), placenta previa (OR 13.577, 95%CI 2.563–71.912), gestational diabetes mellitus (OR = 3.441, 95%CI1.694–6.991), hypertensive disorder complicating pregnancy (OR = 6.034, 95%CI = 3.401–10.704), history of preterm birth (OR = 20.888, 95%CI 2.519–173.218) and reproductive abnormalities (OR = 3.049, 95%CI 1.010–9.206) were independent risk factors. Women who lived in towns and cities (OR = 0.603, 95%CI 0.430–0.846), had a balanced diet (OR = 0.533, 95%CI 0.421–0.675) and had a record of prenatal care (OR = 0.261, 95%CI 0.134–0.510) were less likely to have preterm birth.

Conclusions

Obesity, stressful life events, sexual activity, placenta previa, gestational diabetes mellitus, hypertensive disorder complicating pregnancy, history of preterm birth and reproductive abnormalities are independent risk factors to preterm birth. Identification of remedial factors may inform local health and education policy.     

丙型肝炎病毒F蛋白缺失对病毒复制及感染性的影响

探索了F蛋白缺失及核心蛋白(Core)二级结构改变对丙型肝炎病毒(HCV)复制和感染性的影响．利用定点突变方法,将J6JFH1的核心基因引进5个终止密码子以中断F蛋白的表达,从而获得F蛋白缺失的病毒复制子J6JFH1/ΔF．体外制备RNA转录体,并电穿孔转染Huh7.5.1细胞,采用免疫荧光、实时荧光定量PCR方法以及病毒感染等方法,观察F蛋白缺失对病毒复制、蛋白质表达及转染细胞上清感染性病毒颗粒产生的影响．在此基础上,构建5个单一突变病毒体,对HCV核心蛋白进行二级结构分析,观察核心蛋白二级结构对HCV复制和翻译的影响．结果显示,转染48 h后,J6JFH1/ΔF与野生型J6JFH1相比,J6JFH1/ΔF转染阳性细胞数明显降低,细胞内HCV RNA 水平降低约95%,J6JFH1/ΔF转染后不同时间点细胞上清中HCV RNA拷贝数和病毒颗粒也明显降低．5个单一突变体不影响核心基因二级结构,病毒在细胞内复制和感染性与野生型水平一致．J6JFH1/ΔF所产生的改变可能是由于5处突变导致核心基因二级结构改变而造成的．结果说明,HCV F蛋白缺失不影响病毒的复制翻译及病毒颗粒的包装释放,核心蛋白二级结构的改变对病毒复制和翻译则产生较大影响．