有关SARS病原冠状病毒合并感染组织胞浆菌的探讨

目的探讨SARS病原学的冠状病毒复合组织胞浆菌感染的问题。方法对象为SARS患者尸检1例和南猴(某猴场病死猴)尸检1例,采用病理组织学和免疫组化荧光检测的方法作检查,观察和比较两者尸检材料肺、脾、淋巴结和肝的病理变化和组织内组织胞浆菌的存在。结果1.人SARS和南猴的病理组织学改变极为相似。2.免疫组化结果表明,用人SARS恢复期血清和兔抗组织胞浆菌血清与组织胞浆菌抗原均呈阳性反应,显示此例SARS患者曾感染组织胞浆菌,其次用此两种抗血清分别与人SARS和南猴肺、脾、淋巴结尸检材料反应,均有组织胞浆菌阳性菌体的存在,说明人SARS和南猴脏器均有组织胞浆菌的感染。结论人SARS病原除冠状病毒外,还有组织胞浆菌的合并感染。     

肉苁蓉研究进展

本文就肉苁蓉资源分布、化学成分、分离提纯、药理作用和资源开发利用作一综述,并展望其发展前景     

福建金线莲的化学成分研究Ⅲ

从福建金线莲(Anoectochilus roxburghii)乙醇提取物的己烷萃取部分分得3个化合物和-甾体混合物,三个化合物结构分别鉴定为Sorghumol(1),木栓酮(2)和棕榈酸(3),甾体混合物经EI-MS、ESI-MS／MS技术确定含有24-异丙烯基胆甾醇、开唇兰甾醇、β-谷甾醇、豆甾醇和菜油甾醇。所有化合物均为该植物首次报道,其中化合物1为首次从兰科植物中分得,并首次对其光谱数据进行了详细的分析,化合物2为从该属植物中首次分得。     

多次采血对Wistar大鼠脏器系数的影响

目的研究不同时间间隔经眼眶静脉丛多次采血后,对雄性Wistar大鼠重要脏器系数的影响。方法实验组分别间隔3 d、7 d、10 d,经眼眶静脉丛采血,每次采血1 mL,共采3次。对照组于实验组最后一次采血时采血一次,采血1 mL。每次采血前称量体重,于最后一次采血后将大鼠处死,取心脏、肝脏、肾脏、脾脏、胸腺,称量脏器重量,计算脏器系数。结果间隔3 d多次采血,大鼠的肝、肾系数差异具有显著性（P〈0.05）,间隔7 d、10 d多次采血,大鼠的各脏器系数差异无显著性。结论间隔3 d多次采血对大鼠的肝、肾系数有影响,间隔7 d、10 d多次采血对各脏器系数均无影响。     

Fluorescence spectrometric study on the interaction of tamibarotene with bovine serum albumin

The interaction between tamibarotene and bovine serum albumin (BSA) was studied using fluorescence quenching technique and ultraviolet–visible spectrophotometry. The results of experiments showed that tamibarotene could strongly quench the intrinsic fluorescence of BSA by a dynamic quenching mechanism. The apparent binding constant, number of binding site and corresponding thermodynamic parameters at different temperatures were calculated respectively, and the main interaction force between tamibarotene and BSA was proved to be hydrophobic force. Synchronous fluorescence spectra showed that tamibarotene changed the molecular conformation of BSA. When BSA concentration was 1.00 × 10^?6 mol L^?1, the quenched fluorescence ΔF had a good linear relationship with the concentration of tamibarotene in the range 1.00 × 10^?6 to 12.00 × 10^?6 mol L^?1 with the detection limit of 6.52 × 10^?7 mol L^?1. Copyright © 2010 John Wiley & Sons, Ltd.     

Cinnamic acid pretreatment mitigates chilling stress of cucumber leaves through altering antioxidant enzyme activity

To elucidate the physiological mechanism of chilling stress mitigated by cinnamic acid (CA) pretreatment, a cucumber variety (Cucumis sativus cv. Jinchun no. 4) was pretreated with 50 μM CA for 2 d and was then cultivated at two temperatures (15/8 and 25/18 °C) for 1 d. We investigated whether exogenous CA could protect cucumber plantlets from chilling stress (15/8 °C) and examined whether the protective effect was associated with the regulation of antioxidant enzymes and lipid peroxidation. At 2 d, exogenous CA did not influence plant growth, but induced the activities of some antioxidant enzymes, including superoxide dismutase (SOD, EC 1.15.1.1), catalase (CAT, EC 1.11.1.6), guaiacol peroxidase (GPX, EC 1.11.1.7), glutathione peroxidase (GSH-Px, EC 1.6.4.2) and ascorbate peroxidase (APX, EC 1.11.1.11) in cucumber leaves, and it also elevated the contents of reduced glutathione (GSH) and ascorbate (AsA). When CA was rinsed and the CA-pretreated seedlings were exposed to different temperatures, the antioxidant activities in leaves at 3 d had undergone additional change. Chilling increased the activities of CAT, GSH-PX, APX, GSH and AsA in leaves, but the combination of CA pretreatment and chilling enhanced the antioxidant activities even more. Moreover, chilling inhibited plant growth and increased the contents of malonaldehyde (MDA), superoxide radical (O₂⁻) and hydrogen peroxide (H₂O₂) in cucumber leaves, and the stress resulted in 87.5% of the second leaves being withered. When CA pretreatment was combined with the chilling stress, we observed alleviated growth inhibition and decreased contents of MDA, H₂O₂ and O₂⁻ in comparison to non-pretreated stressed plants, and found that the withered leaves occurred at a rate of 25.0%. We propose that CA pretreatment increases antioxidant enzyme activities in chilling-stressed leaves and decreases lipid peroxidation to some extent, enhancing the tolerance of cucumber leaves to chilling stress.     

Over-expression of FoxM1 leads to epithelial-mesenchymal transition and cancer stem cell phenotype in pancreatic cancer cells

FoxM1 is known to play important role in the development and progression of many malignancies including pancreatic cancer. Studies have shown that the acquisition of epithelial-to-mesenchymal transition (EMT) phenotype and induction of cancer stem cell (CSC) or cancer stem-like cell phenotypes are highly inter-related, and contributes to drug resistance, tumor recurrence, and metastasis. The molecular mechanism(s) by which FoxM1 contributes to the acquisition of EMT phenotype and induction of CSC self-renewal capacity is poorly understood. Therefore, we established FoxM1 over-expressing pancreatic cancer (AsPC-1) cells, which showed increased cell growth, clonogenicity, and cell migration. Moreover, over-expression of FoxM1 led to the acquisition of EMT phenotype by activation of mesenchymal cell markers, ZEB1, ZEB2, Snail2, E-cadherin, and vimentin, which is consistent with increased sphere-forming (pancreatospheres) capacity and expression of CSC surface markers (CD44 and EpCAM). We also found that over-expression of FoxM1 led to decreased expression of miRNAs (let-7a, let-7b, let-7c, miR-200b, and miR-200c); however, re-expression of miR-200b inhibited the expression of ZEB1, ZEB2, vimentin as well as FoxM1, and induced the expression of E-cadherin, leading to the reversal of EMT phenotype. Finally, we found that genistein, a natural chemo-preventive agent, inhibited cell growth, clonogenicity, cell migration and invasion, EMT phenotype, and formation of pancreatospheres consistent with reduced expression of CD44 and EpCAM. These results suggest, for the first time, that FoxM1 over-expression is responsible for the acquisition of EMT and CSC phenotype, which is in part mediated through the regulation of miR-200b and these processes, could be easily attenuated by genistein.     

A missense mutation in PPARD causes a major QTL effect on ear size in pigs

Chinese Erhualian is the most prolific pig breed in the world. The breed exhibits exceptionally large and floppy ears. To identify genes underlying this typical feature, we previously performed a genome scan in a large scale White Duroc × Erhualian cross and mapped a major QTL for ear size to a 2-cM region on chromosome 7. We herein performed an identical-by-descent analysis that defined the QTL within a 750-kb region. Historically, the large-ear feature has been selected for the ancient sacrificial culture in Erhualian pigs. By using a selective sweep analysis, we then refined the critical region to a 630-kb interval containing 9 annotated genes. Four of the 9 genes are expressed in ear tissues of piglets. Of the 4 genes, PPARD stood out as the strongest candidate gene for its established role in skin homeostasis, cartilage development, and fat metabolism. No differential expression of PPARD was found in ear tissues at different growth stages between large-eared Erhualian and small-eared Duroc pigs. We further screened coding sequence variants in the PPARD gene and identified only one missense mutation (G32E) in a conserved functionally important domain. The protein-altering mutation showed perfect concordance (100%) with the QTL genotypes of all 19 founder animals segregating in the White Duroc × Erhualian cross and occurred at high frequencies exclusively in Chinese large-eared breeds. Moreover, the mutation is of functional significance; it mediates down-regulation of β-catenin and its target gene expression that is crucial for fat deposition in skin. Furthermore, the mutation was significantly associated with ear size across the experimental cross and diverse outbred populations. A worldwide survey of haplotype diversity revealed that the mutation event is of Chinese origin, likely after domestication. Taken together, we provide evidence that PPARD G32E is the variation underlying this major QTL.     

基于表达谱芯片和下一代测序技术筛选先天性心脏病胎儿心肌组织差异表达的miRNA

目的 联合采用表达谱芯片和下一代测序技术同时高通量筛选先天性心脏病胎儿心肌组织表达差异的miRNA.方法 实验组为孕中期先天性畸形胎儿,对照组为同胎龄无心脏畸形的难免流产的胎儿,取胎儿心室心肌组织,联合采用Agilent Human 2.0 microRNAs表达谱芯片和SOLiD下一代测序技术同时观察心肌组织microRNA的表达变化,数据采用生物信息学方法进行分析,并用实时PCR方法验证芯片结果.结果 通过差异miRNA筛选,发现先天性心脏畸形组在表达谱芯片和下一代测序中共同差异的24个miRNA,生物信息学预测到1 606个靶基因,靶基因Gene Ontology分析表明其中与细胞进程、代谢过程、生物调控相关的靶基因为主,Pathway显著性分析表明,部分靶基因为生物信号通路中的关键因子;随机挑选共同表达差异的4个miRNA进行验证,结果表明定量PCR检测结果与芯片与下一代测序共同筛选结果基本相符.结论 这些在先天性心脏病中异常表达的miRNA为研究先天性心脏病分子水平上的发病机制提供了重要的线索,将有可能为心脏相关疾病的诊断和治疗提供新的靶点和研发新的药物.