Study on noncovalent complexes of cytotoxic protoberberine alkaloids with double-stranded DNA by using electrospray ionization mass spectrometry

The noncovalent complexes of four cytotoxic protoberberine alkaloids that is, berberine, palmatine, jatrorrhizine, and coptisine with double-stranded oligodeoxynucleotides d(AAGAATTCTT)(2) were investigated by electrospray ionization mass spectrometry. These four active components from Chinese herbal medicines showed both 1:1 and 1:2 binding stoichiometries, independent on the alkaloid-to-DNA ratios. Binding affinities in the order of palmatine> or =jatrorrhizine>coptisine>berberine with d(AAGAATTCTT)(2) were obtained. Additionally, the preliminary results indicated that berberine had some sequence selectivities.     

东北三省野生北细辛资源调查报告

通过对东北三省野生北细辛资源的地理分布、生态环境、群落类型、单位面积蕴藏量等进行调查研究,为野生北细辛资源保护与可持续利用措施的制定提供依据。     

Expression and purification of chicken beta interferon and its antivirus immunological activity

Interferon beta (IFN-β) belongs to a class of natural proteins that can inhibit virus replication. In this paper, nucleic acid sequence encoding chicken interferon beta (chIFN-β) mature protein was cloned and highly expressed in Escherichia coli (E. coli) by 1mM IPTG induction. The expressed chIFN-β was about 20% of total bacterial protein. The recombinant protein in form of inclusion body was then solubilised, refolded and purified to a purity of greater than 95% by immobilized metal ion affinity chromatography (IMAC). This recombinant chIFN-β could inhibit vesicular stomatitis Indiana virus (VSV) and infectious bursal disease virus (IBDV) replication in vitro. Animal experiments showed that the recombinant chIFN-β could decrease pathological lesions caused by the IBDV in bursa of Fabricius. These results will provide useful information for further investigations on veterinary clinical applications and fundamental research.     

苏州地区野生黄颡鱼寄生虫多样性及其寄生特性

2002年2～9月对苏州地区野生黄颡鱼寄生虫进行了系统调查,发现其体内外寄生虫共有37种,分别隶属于5门11纲14目22科28属,其中原生动物门13种,占所有寄生虫的35．1％;扁形动物门15种,占40．5％;线形动物门5种,占13．5％;节肢动物门3种,占8．1％;环节动物门1种,占2．7％。从不同体长组黄颡鱼的寄生虫感染率和平均感染强度变化以及季节变化的结果表明,黄颡鱼对许多淡水寄生虫易感,而且吸虫与纤毛虫是苏州地区黄颡鱼的主要寄生虫。研究还发现,当黄颡鱼体长超过20cm时,寄生虫的感染程度显著减弱。     

基于环介导等温扩增技术的微流控芯片在病原菌检测方面的研究进展

环介导等温扩增(LAMP)技术是一种新兴的核酸恒温扩增技术,与微流控芯片技术相结合,可实现对病原菌的快速检测,具有特异性强、灵敏度高、操作简单等优点。本文根据不同终产物的检测方法对目前检测病原菌的相关微流控LAMP芯片进行了分类与介绍,并对技术的改进和存在的问题进行了分析,以期为后续的相关研究提供参考。     

温室白粉虱触角miRNA转录组分析及调控嗅觉相关基因miRNA的鉴定

microRNA(miRNA)是一类真核生物中内源性的非编码小RNA,在基因转录后水平调控靶基因的小分子.温室白粉虱(Trialeurodes vaporariorum)是一种危害多种蔬菜、花卉及农作物等的世界性害虫,可以导致植物细菌性病害的传播和流行,其触角对温室白粉虱的取食、行为和生长发育等起到了重要作用.本研究以...     

Distinct reactions catalyzed by bacterial and yeast trans-aconitate methyltransferases

The trans-aconitate methyltransferase from the bacterium Escherichia coli catalyzes the monomethyl esterification of trans-aconitate and related compounds. Using two-dimensional (1)H/(13)C nuclear magnetic resonance spectroscopy, we show that the methylation is specific to one of the three carboxyl groups and further demonstrate that the product is the 6-methyl ester of trans-aconitate (E-3-carboxy-2-pentenedioate 6-methyl ester). A similar enzymatic activity is present in the yeast Saccharomyces cerevisiae. Although we find that yeast trans-aconitate methyltransferase also catalyzes the monomethyl esterification of trans-aconitate, we identify that the methylation product of yeast is the 5-methyl ester (E-3-carboxyl-2-pentenedioate 5-methyl ester). The difference in the reaction catalyzed by the two enzymes may explain why a close homologue of the E. coli methyltransferase gene is not found in the yeast genome and furthermore suggests that these two enzymes may play distinct roles. However, we demonstrate here that the conversion of trans-aconitate to each of these products can mitigate its inhibitory effect on aconitase, a key enzyme of the citric acid cycle, suggesting that these methyltransferases may achieve the same physiological function with distinct chemistries.     

小麦抗禾缢管蚜的生化研究

通过福林法、葸酮法、滴定法等分别测定了不同抗蚜性小麦品种植株中酚、糖含量及酸度。结果表明：小麦对禾缢管蚜尺Rhopalosiphum padi(Linnaeus)的抗性与小麦体内酚含量有关,抗性强的小麦其体内含酚量相对高,反之低。同时小麦抗性的强弱与体内糖含量,酸度亦有相关性。另外还测走了在不同抗性小麦品种上生长的蚜虫体内淀粉酶及羧酸酯酶的活性,结果表明在抗性强的小麦品种上生长的蚜虫体内淀粉酶,羧酸酯酶活性强,反之弱。     

Functional dissection of lupus susceptibility loci on the New Zealand black mouse chromosome 1: evidence for independent genetic loci affecting T and B cell activation

In previous work, we demonstrated linkage between a broad region on New Zealand Black (NZB) chromosome 1 and increased costimulatory molecule expression on B cells and autoantibody production. In this study, we produced C57BL/6 congenic mice with homozygous NZB chromosome 1 intervals of differing lengths. We show that both B6.NZBc1(35-106) (numbers denote chromosomal interval length) and B6.NZBc1(85-106) mice produce IgG anti-nuclear autoantibodies, but B6.NZBc1(35-106) mice develop significantly higher titers of autoantibodies and more severe renal disease than B6.NZBc1(85-106) mice. Cellular analysis of B6.NZBc1(85-106) mice revealed splenomegaly and increased numbers of memory T cells. In addition to these features, B6.NZBc1(35-106) mice had altered B and T cell activation with increased expression of CD69, and for B cells, costimulatory molecules and MHC. Introduction of an anti-hen egg white lysozyme Ig transgene, as a representative nonself-reactive Ig receptor, onto the B6.NZBc1(35-106) background corrected the B cell activation phenotype and led to dramatic normalization of splenomegaly and T cell activation, but had little impact on the increased proportion of memory T cells. These findings indicate that there are multiple lupus susceptibility genes on NZB chromosome 1, and that although B cell defects play an important role in lupus pathogenesis in these mice, they act in concert with T cell activation defects.     

上皮细胞分裂过程中中等纤维的变化

Immunofluorescence microscopy was used to follow the rearrangement of keratin filaments and vimentin filaments during mitosis in Vero and HeLa cell lines. The experiment results showed that the three dimensional organization and structure of intermediate filaments changed drastically during mitosis. The behavior of intermediate filaments was different in these two epithelial cell lines. In mitotic Vero cells the keratin filaments and vimentin filaments maintained their filamentous structure and formed a cage around the mitotic apparatus. In mitotic HeLa cells the keratin filaments and vimentin filaments reorganized extensively and formed granular cytoplasmic bodies. The ratio of granular cytoplasmic body formation changed in different mitotic phase. The interphase intermediate filament network was reconstructed after mitosis. It is proposed that the state of intermediate filament network in these cells is cell cycle-dependent and intermediate filaments may have some skeletal role in mitosis.