抗黄曲霉毒素B1单克隆抗体的制备研究

从影响融合率的2个主要因素探讨骨髓瘤细胞系Sp2/0细胞与黄曲霉毒素B_1免疫的脾细胞融合的最佳条件,使融合率达到100%.经筛选和克隆化,获得3株稳定分泌单克隆抗体的细胞株,分别命名为3B3、3H9、5G9.经过鉴定3株均为IgG_1亚类.其中3B3抗体与其他黄曲霉毒素几乎不发生交叉反应,腹水效价为1∶2×10~5,亲和力常数为3.1×10~7 L/mol,竞争性ELISA测出3B3抗体的最低反应浓度为0.05μg/L标准AFB_1样品的的回收率达96%.另外两株腹水抗体水平低,交叉反应强烈,腹水效价仅在1∶10~4数量级.     

耐高浓度甘油的1,3-丙二醇生产菌的诱变选育

利用紫外线对克雷伯杆菌进行诱变,筛选出耐高浓度甘油且1,3-丙二醇(1,3-PD)产量较高的突变株KpⅥ.实验结果表明,在距离34 cm,功率30 W的紫外灯垂直照射下,最佳紫外诱变时间为6 min,此时,致死率为90.9%.克雷伯杆菌经过紫外诱变后,菌落明显增大,是原始菌株的2~4倍;变异菌株KpⅥ经过6代遗传稳定性考察,甘油消耗率和1,3-PD产量稳定,且保持了较高水平.在甘油质量浓度为90 g.L-1的条件下,变异菌株KpⅥ的甘油消耗率为98.3%,甘油转化率为50.4%,1,3-PD产量为44.81 g.L-1,生产能力达到0.75 g.(L.h)-1.     

Understanding the importance of selenium and selenoproteins in muscle function

Selenium is an essential trace element. In cattle, selenium deficiency causes dysfunction of various organs, including skeletal and cardiac muscles. In humans as well, lack of selenium is associated with many disorders, but despite accumulation of clinical reports, muscle diseases are not generally considered on the list. The goal of this review is to establish the connection between clinical observations and the most recent advances obtained in selenium biology. Recent results about a possible role of selenium-containing proteins in muscle formation and repair have been collected. Selenoprotein N is the first selenoprotein linked to genetic disorders consisting of different forms of congenital muscular dystrophies. Understanding the muscle disorders associated with selenium deficiency or selenoprotein N dysfunction is an essential step in defining the causes of the disease and obtaining a better comprehension of the mechanisms involved in muscle formation and maintenance. Received 13 July 2005; received after revision 9 September 2005; accepted 4 October 2005     

Cholera toxin structure, gene regulation and pathophysiological and immunological aspects

Many notions regarding the function, structure and regulation of cholera toxin expression have remained essentially unaltered in the last 15 years. At the same time, recent findings have generated additional perspectives. For example, the cholera toxin genes are now known to be carried by a non-lytic bacteriophage, a previously unsuspected condition. Understanding of how the expression of cholera toxin genes is controlled by the bacterium at the molecular level has advanced significantly and relationships with cell-density-associated (quorum-sensing) responses have recently been discovered. Regarding the cell intoxication process, the mode of entry and intracellular transport of cholera toxin are becoming clearer. In the immunological field, the strong oral immunogenicity of the non-toxic B subunit of cholera toxin (CTB) has been exploited in the development of a now widely licensed oral cholera vaccine. Additionally, CTB has been shown to induce tolerance against co-administered (linked) foreign antigens in some autoimmune and allergic diseases. Received 25 October 2007; accepted 12 December 2007     

The roles of poly(ADP-ribose)-metabolizing enzymes in alkylation-induced cell death

Poly(ADP-ribose) (PAR) has been identified as a DNA damage-inducible cell death signal upstream of apoptosis-inducing factor (AIF). PAR causes the translocation of AIF from mitochondria to the nucleus and triggers cell death. In living cells, PAR molecules are subject to dynamic changes pending on internal and external stress factors. Using RNA interference (RNAi), we determined the roles of poly(ADP-ribose) polymerases-1 and -2 (PARP-1, PARP-2) and poly(ADP-ribose) glycohydrolase (PARG), the key enzymes configuring PAR molecules, in cell death induced by an alkylating agent. We found that PARP-1, but not PARP-2 and PARG, contributed to alkylation-induced cell death. Likewise, AIF translocation was only affected by PARP-1. PARP-1 seems to play a major role configuring PAR as a death signal involving AIF translocation regardless of the death pathway involved. Received 7 November 2007; received after revision 19 December 2007; accepted 21 December 2007 O. Cohausz, C. Blenn: These two authors contributed equally to this work.     

Endocrine-dependent expression of circadian clock genes in insects

Current models state that insect peripheral oscillators are directly responsive to light, while mammalian peripheral clock genes are coordinated by a master clock in the brain via intermediate factors, possibly hormonal. We show that the expression levels of two circadian clock genes, period (per) and Par Domain Protein 1 (Pdp1) in the peripheral tissue of an insect model species, the linden bug Pyrrhocoris apterus, are inversely affected by contrasting photoperiods. The effect of photoperiod on per and Pdp1 mRNA levels was found to be mediated by the corpus allatum, an endocrine gland producing juvenile hormone. Our results provide the first experimental evidence for the effect of an endocrine gland on circadian clock gene expression in insects. Received 31 October 2007; received after revision 7 January 2008; accepted 9 January 2008 D. Dolezel, L. Zdechovanova: These authors contributed equally to this work.     

灰色预测模型特性的研究

对 GM(1 ,1 )模型特性进行了研究 ,证明了 GM(1 ,1 )模型是有偏差的指数模型 ,分析了模型偏差的特性 ,进而从理论上阐明了 GM(1 ,1 )模型误差的实质 .     

TIBO类衍生物抗HIV-1活性的QSAR研究

在分子图邻接矩阵的基础上,定义并计算了TIBO类衍生物原子的点价值iδ,利用图论方法建构了新的分子连接性指数mE,基于多元回归技术发展了对TIBO类衍生物药物的活性参数作出精确估算的定量结构-活性相关关系,得到的多元回归方程为:P=-274.563 80E-1 65.530 61E-1-149.681 6Jx-'1 26.084 7计算结果表明,抗H IV-1活性参数的计算值和实验值的一致性令人满意。