Development and Evaluation of a DAS-ELISA for Rapid Detection of Tembusu Virus Using Monoclonal Antibodies against the Envelope Protein

Since April 2010, Tembusu virus (TMUV) which is a contagious pathogen of waterfowls, causing symptoms of high fever, loss of appetite and fall in egg production, has been reported in east of China. A double antibody sandwich enzyme-linked immunosorbent assay (DAS-ELISA) which detects for TMUV was developed, using two monoclonal antibodies (mAbs) against the TMUV envelope (E) protein. BALB/c mice were immunized with purified recombinant E protein expressed in E. coli. Three hybridoma cell lines designated as 12B1, 10C6 and 2D2, were screened by cell fusion and indirect ELISA for their ability to recognize different linear epitopes on the E protein, and were characterized subsequently. High-affinity mAbs 12B1 and 2D2 were used as capture and detection antibodies, respectively. The reaction conditions for the DAS-ELISA were optimized for TMUV detection. The cross-reactivity of the DAS-ELISA was determined using TMUV, duck plague virus, avian influenza virus subtype H9, Newcastle disease virus, duck hepatitis A virus type 1 and duck reovirus samples. A total of 191 homogenized tissues of field samples were simultaneously detected by DAS-ELISA and by RT-PCR. The former was found to have a high specificity of 99.1% and a sensitivity of 93.1%. These results reveal a positive coincidence between DAS-ELISA and RT-PCR at a coincidence rate of 95.8%. The method developed in this study can be used for the diagnosis of TMUV infection of duck origin.     

山西翅果油树的适生区预测及其对气候变化的响应

研究濒危物种生境在气候变化下的响应对保护物种多样性和保持生态系统功能完整性具有重要意义.本文选取我国特有濒危植物翅果油树为研究对象,以该物种73个野外调查数据和35个环境因子为基础,应用最大熵模型对山西翅果油树当前的适生分布区进行预测;进而结合政府间气候变化专门委员会第五次评估报告发布的气候模式数据,探讨未来不同气候情景下山西翅果油树分布格局的变化趋势.结果表明:受试者工作特征曲线分析法的AUC值为0.987,表明模型的模拟精度很好且预测可靠性高;刀切法检验结果显示,降水量季节变化、温度年变化范围、年均温、等温线、表层土p H值和年降水量是影响翅果油树分布的主要环境因子,其累积贡献率达到了94.8%;当前,山西翅果油树的适生区主要集中在山西省吕梁山南部和中条山地带;未来不同气候情景下,到21世纪70年代翅果油树适生区面积均有不同幅度的缩减,低浓度情景(RCP 2.6)下呈先增后减趋势,中高浓度情景(RCP 4.5和RCP8.5)下响应较敏感且呈先减后增趋势.两个不同适生区的空间分布格局对气候变化也有不同的响应,吕梁山南部表现出纬度方向的轻微波动,而中条山地带则是海拔方向的迁移.     

禽畜养殖粪便中多重抗生素抗性细菌研究

通过对新乡地区8家养猪场和11家养鸡场饲喂抗生素情况的调研,发现头孢氨苄、阿莫西林、卡那霉素、庆大霉素等4种抗生素是该地区被普遍使用的兽药抗生素。通过多点取样法和微生物培养技术对3家养鸡场和3家养猪场不同养殖时期的粪便进行单一抗生素和多重抗生素抗性细菌的检测,结果表明养鸡场堆置1周的粪便中抗头孢氨苄的细菌比例最高,达到65.90%,对所研究的3种和4种抗生素同时抗性的比例高达8.60%—12.51%和9.73%,明显高于饲喂中药的对照养鸡场样本检测结果(0.02%—2.73%和0.12%)。养猪场堆置1周的粪便中检测到抗头孢氨苄的细菌比例也是最高,达到49.12%上,但养猪场粪便中多重抗生素抗性细菌的比例明显低于养鸡场。同时研究发现,在两种养殖场中,幼龄期粪便中检测到的多重抗性细菌比例明显高于成熟期粪便,这可能与养殖过程中鸡、猪在幼龄期由于防病和促生长等因素而同时大剂量使用多种抗生素有关。     

IL-33-ST2 pathway regulates AECII transdifferentiation by targeting alveolar macrophage in a bronchopulmonary dysplasia mouse model

Evidence points to the indispensable function of alveolar macrophages (AMs) in normal lung development and tissue homeostasis. However, the importance of AMs in bronchopulmonary dysplasia (BPD) has not been elucidated. Here, we identified a significant role of abnormal AM proliferation and polarization in alveolar dysplasia during BPD, which is closely related to the activation of the IL-33-ST2 pathway. Compared with the control BPD group, AMs depletion partially abolished the epithelialmesenchymal transition process of AECII and alleviated pulmonary differentiation arrest. In addition, IL-33 or ST2 knockdown has protective effects against lung injury after hyperoxia, which is associated with reduced AM polarization and proliferation. The protective effect disappeared following reconstitution of AMs in injured IL-33 knockdown mice, and the differentiation of lung epithelium was blocked again. In conclusion, the IL-33-ST2 pathway regulates AECII transdifferentiation by targeting AMs proliferation and polarization in BPD, which shows a novel strategy for manipulating the IL-33–ST2-AMs axis for the diagnosis and intervention of BPD.     

Antibodies specific for heat shock proteins in human and murine malaria

Heat shock proteins (HSPs) are immunodominant antigens recognized by the host immune system in various infectious diseases. We analyzed HSP-specific antibodies, including immunoglobulin G (IgG), IgM and IgA, in sera from malaria patients in Thailand by using an enzyme-linked immunosorbent assay. All of the antibodies to HSP90 were remarkably increased in the patients compared with those in controls, while only IgM to HSP70 or IgA to HSP65 was significantly elevated. Further experiments showed that anti-HSP IgG was significantly increased in C57BL/6 mice infected with a non-lethal strain of Plasmodium yoelii, with anti-HSP90 IgG being the most elevated. These results suggest that the antigenic potential of HSP90 is higher than those of HSP70 and HSP65 in malaria infection.     

三株芽胞杆菌菌株对松材线虫低温存活与繁殖的影响

为明确细菌在松材线虫生态适应性中的作用,本研究选择与致病相关的松材线虫伴生细菌GD1、马尾松内生细菌GD2以及具有杀松材线虫活性的湿地松内生细菌NJSZ-13为试验对象,测定经这3株芽胞杆菌菌株3个浓度低温驯化10、15和20 d后,在冷冻条件下松材线虫强毒虫株AMA3、中毒虫株AA3和弱毒虫株YW4的存活率和繁殖量。结果表明：低温驯化15 d和20 d后3株菌株对不同毒力线虫的活力影响较驯化10 d后的更显著。在低温驯化15 d、-20℃冷冻处理1 h后,5×10⁶ CFU/mL浓度菌株GD1处理下,虫株AMA3、AA3和YW4的存活率分别为77.22%、83.68%和84.26%,与对照差异显著;5×10⁵ CFU/mL浓度菌株GD1处理下,虫株AMA3、AA3和YW4的存活率分别为75.76%、80.67%和81.50%,与对照差异显著。5×10⁶ CFU/mL和5×10⁵ CFU/mL浓度菌株GD2处理下,与GD1处理组结果相似,菌株NJSZ-13处理组则与菌株GD1和GD2的结果相反。低温驯化15 d、-20℃冷冻处理1 h后,5×10⁶ CFU/mL浓度菌株GD1处理下,虫株AMA3、AA3和YW4的繁殖量分别为7 530、9 317和12 793条/皿,与对照（3 192、3 840和5 823条/皿）差异显著;5×10⁵ CFU/mL浓度菌株GD1处理时,3个虫株的繁殖量均与对照差异显著。而菌株GD2和NJSZ-13处理后,3个虫株的繁殖量均无显著变化。表明不同芽胞杆菌对松材线虫的低温适应性影响存在差异,松材线虫伴生细菌GD1和马尾松内生细菌GD2能增强其低温适应性,而湿地松内生细菌NJSZ-13菌株则相反。     

Protoplast culture and plant regeneration ofPinellia ternata

A study was undertaken to develop a protoplast regeneration system for pinellia. A yield of 19 29 x 10⁵ protoplasts/g F. W. could be obtained from cell suspension cultures incubated in a digestion enzyme solution with 2% cellulase Onzuka R-10, 10% pectinase (Sigma), 0.01% pectolyase Y23. K8P and modified MS media were used to culture protoplasts in: a) liquid, b) liquid-solid double layer, or c) agarose embedded protoplast culture. The former two were conducive to colony formation from protoplast-derived cells. The frequency of cell division was about 8% after 3 days in culture. Gradually adding fresh medium of lower osmotic pressure into the medium for protoplast culture favored cell division. Calli (1–2 mm in diameter) formed after 30–40 days in culture. The calli transferred onto medium supplemented with KT (0.5 mg 1^–1) and NAA (0.2 mg 1)^–1) could regenerate plants after 40–50 days. Of 47 plantlets transplanted into plots, 29 flowered and were fertile.Abbreviations 2,4-D 2,4-dichlorophenoxyacetic acid - NAA -naphthaleneacetic acid - KT kinetin - CH casein hydrolysate     

甘南高山林线岷江冷杉—杜鹃种群结构与动态

高山林线是一种典型的生态交错带,是对气候反映最敏感的地区之一。甘肃南部高山林线区域主要以原始岷江冷杉种群和杜鹃种群为优势种,通过对岷江冷杉和杜鹃种群建立静态生命表,绘制存活曲线描述其结构特征,利用种群数量动态预测时间序列分析定量研究未来的发展趋势。结果显示:(1)岷江冷杉种群幼苗比较丰富,能很好的维持种群个体的自疏死亡,存活曲线呈Deevey-Ⅲ型;杜鹃种群幼苗缺乏,存活曲线趋向于Deevey-Ⅰ型;死亡曲线和危险率曲线都随着龄级的增加而增加,杜鹃种群的死亡率在各个龄级一直大于岷江冷杉种群,危险率在Ⅱ龄级以后杜鹃种群也始终大于岷江冷杉种群。(2)岷江冷杉种群结构动态变化指数Vpi大于修正后的种群结构动态变化指数V′pi且大于0,而杜鹃种群结构动态变化指数Vpi小于修正后的种群结构动态变化指数V′pi且小于0,则岷江冷杉种群属于增长型,杜鹃种群属于衰退型,岷江冷杉、杜鹃随机干扰极大值分别为0.027、0.011,说明二者对外界干扰均比较敏感。(3)杜鹃种群时间序列预测为前期幼苗比较缺乏,中期稳定,后期衰退的动态特征,而岷江冷杉种群表现出各龄级时间变化较小,幼苗个体数较多,种群为稳定增长型,岷江冷杉更能适应甘肃南部高山林线区域当前环境。     

菊科入侵植物三叶鬼针草的繁殖特征及其与入侵性的关系

三叶鬼针草(Bidens pilosa)是一种危害严重的菊科入侵植物.通过实验观察和人工控制套袋等方法,对其花序开花动态、花粉胚珠比(P/O)、自交亲和性、花粉活力、访花昆虫和种子(瘦果)的萌发率等与繁殖相关的特征进行了研究,探讨了这些繁殖特征与入侵性的关系.三叶鬼针草在10-11月开花,单个花序的花期约为5-6天.每小花的花柱基部有圆筒状的蜜腺环绕.单个花序内可自交亲和,自交结实率和花粉活力均较高,其P/O值为1754.12士29.87.主要访花者为灰蝶科(Lycaenidae)、粉蝶科(Pjerjdae)和茧蜂科(Braconidae)昆虫.三叶鬼针草所具有的灵活交配机制是其入侵成功的重要因素.此外,三叶鬼针草结实量大、种子产生迅速且适于传播,以及种子萌发范围广和短期快速萌发等特性也增强了其入侵性.