产气荚膜梭菌ε毒素的细胞毒机制及致病机理的研究进展

产气荚膜梭菌ε毒素（Epsilon toxin ，ETX）由B、D型产气荚膜梭菌产生并分泌至宿主动物体内，在临床上主要症状为肠毒血症．ETX属于以七聚体形式存在的β‐样成孔毒素，它能够形成由14个β折叠片组成的“β‐桶状”结构，这个“β‐桶状”结构可以插入真核细胞的质膜形成穿孔．在细胞水平，ETX能够迅速使细胞膜肿胀、多种细胞器破坏，最终导致靶细胞的坏死．在哺乳动物体内，ETX能够使哺乳动物血管产生水肿，从而穿透血脑屏障而聚积在动物肾和脑中，导致机体随着谷氨酸盐的释放而产生过度兴奋，这一系列反应的发生可以引起机体出现脑水肿和肾衰竭，最终导致动物的死亡．目前， ETX备受关注的主要原因不仅仅因为它是一种β‐样成孔毒素，而是可以作为潜在的一种工具类药物，经改造后可以携带治疗药物在短时间内靶向性地到达哺乳动物脑和中枢神经系统，继而为脑和中枢神经系统疾病的治疗提供新的方向．结合国内外相关研究，对ETX细胞毒机制及致病机理进行了综和评述．     

Combined-modality treatment of adductor spasmodic dysphonia with botulinum toxin and voice therapy

A combined-modality treatment program consisting of botulinum toxin injection (Botox) and voice therapy was used to treat 17 subjects diagnosed with adductor spasmodic dysphonia (ADD SD). Ten subjects with ADD SD served as the control and were given Botox only. Voice therapy after Botox injection was directed toward reducing the hyperfunctional vocal behaviors, primarily glottal overpressure at voice onset and anterior-posterior squeezing. The results indicated that subjects who underwent combined-modality treatment maintained significantly higher mean airflow rates for significantly longer periods. Moreover, there was a carryover effect in these patients when they received Botox only. Adductor spasmodic dysphonia is treated most effectively when intrinsic laryngeal muscle spasms are reduced or eliminated by Botox injection and extrinsic hyperfunctional vocal behaviors are treated with voice therapy     

Structure and enantioselective synthesis of polyamine toxin MG30 from the venom of the spider Macrothele gigas

A novel polyamine toxin, named MG30, was isolated from the venom of the spider, Macrothele gigas, and its structure was elucidated by two-dimensional NMR and mass analysis. In addition, the enantioselective synthesis of MG30 was achieved to assign its absolute stereochemistry.     

An optical surface plasmon resonance biosensor for determination of tetanus toxin

Surface plasmon resonance (SPR) has been successfully applied for the simple, rapid, and label-free assay of various biomolecules. This assay evaluates a novel wavelength modulation SPR biosensor for the detection of tetanus toxin. The wavelength modulation SPR biosensor is designed based on fixing the incident angle of light and measuring the reflected intensities in the resonance wavelength range spanning 400-800 nm simultaneously. Tetanus toxin (TeNT), one of the most potent toxins known, is synthesized as a 150 kDa single polypeptide chain. The SPR biosensor has been shown to be capable of directly detecting concentration of tetanus toxin as low as 0.028 Lf ml⁻¹. Under selected experimental conditions, the SPR biosensor has a good reproducibility, sensitivity and reversibility. The results illustrate how wavelength modulation SPR biosensor can be used to detect biomolecular interactions.     

Competition in the bioreactor with general quadratic yields when one competitor produces a toxin

Microorganisms produce toxins against its competitors sometimes, and variable yields are useful to explain the observed oscillatory behavior in the reactor. In this paper, a model with general quadric yields of competition in the bioreactor of two competitors for a single nutrient where one of the competitors can produce toxin against its opponent, is proposed. We analyze the asymptotic behavior of the model in terms of the relevant parameters. The conditions of the three dimensional Hopf bifurcation, and the existence of limit cycles in the nutrient-organism phase plane are obtained.     

Solid-phase synthesis of N-labeled acylpentamines as reference compounds for the MS/MS investigation of spider toxins

A solid-phase route for synthesis of ¹⁵N-labeled acylpolyamines is described. Utilizing alkylation at benzylic N-atom as a key step, ¹⁵N-atoms are incorporated by stepwise construction of the polyamine framework on the solid support. The derivatives were used as reference compounds for the investigation of the MS/MS behavior of spider toxins.     

棉花黄萎病毒素在早期抗病性检测中的应用研究

用棉花黄萎病（Ｖ．ｄａｈｌｉａｅ）毒素,处理不同抗性品种二叶期幼苗,结果表明,黄萎病毒素对棉花幼苗有明显致萎作用,其萎蔫指数与田间病情指数呈显著正相关,同时发现黄萎病毒素对种子发芽也有明显的抑制作用     

卟啉杀虫剂对稻蝗的毒杀作用及机理初探

以太原晋源区的中华稻蝗为材料，用以5-氨基乙酰丙酸(ALA)为主要成份的卟啉杀虫剂作用蝗虫，7d内处理组雄虫全部死亡，而对照组雄虫死亡数约为一半，雌虫死亡数在低浓度下无明显差异．用荧光检测法和考马斯亮蓝蛋白测定法对试虫作进一步的毒性分析，发现卟啉杀虫荆作用于蝗虫后，导致雄虫体内每克组织蛋白含量与对照组相比显著降低，A分析组平均降低73．049mg／g，B分析组降低106．271mg／g．雌虫体内每克组织蛋白含量与对照组相比下降不显著，A分析组平均降低22．741mg／g，B分析组为6．640mg／g．由此得知，卟啉杀虫剂对试虫的作用效果与试虫体内每克组织蛋白含量呈相关关系．此外，分析表明，卟啉杀虫荆作用于试虫后，处理组与对照组相比，试虫体内每毫克蛋白原卟啉Ⅸ(PpⅨ)的含量普遍提高，这一点与Constantin A．Rebeiz的部分实验结果基本吻合．同时还发现，A分析组中雄虫平均每毫克蛋白PpⅨ含量处理组比对照组高0．351gg／mg，雌虫的高0．277pg／mg，前者比后者多0.074pg／mg．B分析组中雄虫平均每毫克蛋白PpⅨ含量处理组比对照组高0．171μg／mg，雌虫的高0．103μg／mg，前者比后者高0．068μg／mg．从实验结果可以看出卟啉杀虫剂对试虫的作用效果与试虫体内每毫克蛋白中PpⅨ含量呈相关关系，结果表明卟啉杀虫剂对试虫的作用效果是由PpⅨ的光敏毒性引起的．     

稻瘟病菌粗毒素对水稻幼胚愈伤组织的影响及抗性筛选

利用目前稻瘟病不同的优势小种菌株的液体培养提取的粗毒素对水稻幼胚进行处理,稻瘟病菌粗毒素提取液对水稻幼胚的愈伤的诱导和分化的有明显的抑制效应。随着毒素浓度的增加,水稻胚性愈伤获得率和分化能力显著降低。在诱导培养基中加入毒素对幼胚的筛选取效果较好,可以获得较多的胚性愈伤和较多的分化苗。培养基中毒素的浓度处理以30%效果好。水稻幼胚的抗性筛选过程中胚性愈伤获得和分化苗数较高,是很好的培养材料;而且不同的水稻品种产生的耐性不同,并可以同时筛选出抗稻瘟病的突变体。     

百日咳毒素的等电点测定及层析分离

百日咳毒素是百日咳杆菌(Bordetellapertussis)产生的一种主要毒力因子,也是百日咳菌苗的主要成分之一.用等电聚焦法测得其等电点为pH6 8.将百日咳杆菌液体培养液在等电点盐析后,通过DEAE-Sephadex-A50阴离子交换剂进一步分离纯化了百日咳毒素.ELISA测定其比活力表明,3批样品的提纯倍数分别为1 47,1 37和1 36.