胎盘型谷胱甘肽S－转移酶基因在胃癌中的表达

用Ｄｉｇ－ＧＳＴ－πｃＤＮＡ探针分子杂交方法,检测了正常胃组织,胃癌及相应癌旁正常组织中ＧＳＴ－πＤＮＡ和ＧＳＴ－πＲＮＡ水平,发现ＧＳＴ－πＤＮＡ水平没有明显变化,而ＧＳＴ－πＲＮＡ在８例胃癌组织中有６例高于正常胃组织,在１２例低分化腺癌中有７例癌旁正常组织高于相应癌组织,表明ＧＳＴ－π基因表达增加与胃癌有关,而且早于细胞形态的变化。     

《代谢性骨病生物考古学》评介

<正>The Bioarchaeology of Metabolic Bone Disease(Second Edition)《代谢性骨病生物考古学》（第2版）由Megan B. Brickley, Simon Mays和Rachel Ives编著。代谢性骨病(Metabolic bone disease)是指导致正常骨形成、吸收或矿化发生系统性改变的疾病或疾病组合。代谢性骨病多与营养不良和激素失调有关,如缺乏维生素C(坏血病)、缺乏维生素D(佝偻病或软骨病)、缺乏铁微量元素（贫血症）、骨质疏松症等。此外,在欧洲,佩吉特氏骨病已成为仅次于骨质疏松症的第二大代谢性骨病。作为一种影响骨骼的疾病,现代人类和古代人类的骨骼上均有发现代谢性骨病的存在。     

细胞膜脂质流动性的不均一性与细胞分裂动力学的关系

细胞腊脂流动性在不同类属细胞存在着差异,其差异的程度取决于细胞的生理和生化特性。正常淋巴细胞、肺腺癌、肺鳞癌细胞以及结核细胞膜脂流动发生 分别为２．５１７±０．２６７、２２．５５７±３．７７１,３２．８７５±９．７０９和４．０２６±０．７２２。细胞分裂动力学与膜脂质流动性有关系。细胞分裂及其程度是膜脂质流动性差异的物质基础,同时并受细胞膜脂质的组成,脂蛋白生化以及外界因素的ｐＨ、Ｃａ＾２＋等影响,     

Factors Affecting Plant Regeneration from Tissue Cultures of Chinese Leymus (Leymus chinensis)

Chinese leymus (Leymus chinensis Trin.) is a perennial grass of the Gramineae, which is widely distributed in China, Mongolia and in Russian-Siberian. In order to explore the potential of biotechnology for genetic improvement of this forage grass, an efficient tissue culture system was established and the factors affecting plant regeneration were evaluated. Immature inflorescence segments 3–5 mm in length from eight accessions were cultured on N6 medium supplemented with 2.26–22.60 µM 2,4-D. The callus induction frequency ranged from 72.11 to 82.19%. Shoots were differentiated from the calli on N6 medium containing 4.65 µM kinetin and 4.44 µM BA. Viable regenerants were developed on hormone-free medium. Normal plants were obtained after natural vernalization in the field. The plant regeneration frequency in Chinese leymus was associated with different genotypes and different combinations of growth regulators in medium. The concentration of 2,4-D in the callus induction medium had a strong effect on successive plant regeneration. Relatively higher concentrations of 2,4-D (i.e., 9.04 and 22.60 µM) were more favorable to the plant regeneration than lower ones (i.e., 2.26 and 4.52 µM). This is the first report on plant regeneration in vitro in L. chinensis.     

抗BmNPV即刻早期蛋白三联ribozyme在家蚕细胞中的表达

为了阻断家蚕核多角体病毒（BmNPV）的基因表达,以BmNPV的即刻早期蛋白基因(IE)为靶序列,设计了三联ribozyme．体外切割反应表明,该ribozyme能特异地切割靶序列的mRNA;细胞实验表明,细胞中表达的ribozyme也能够特异地切割靶序列,从而使受BmNPV感染的Bm-N细胞中的多角体减少约30％．     

Isolation,characterization and application of a species-specific repeated sequence from Haynaldia villosa

A species-specific repeated sequence, pHvNAU62, was cloned from Haynaldia villosa, a wheat relative of great importance. It strongly hybridized to H. villosa, but not to wheat. In situ hybridization localized this sequence to six of seven H. villosa chromosome pairs in telomeric or sub-telomeric regions. Southern hybridization to whea-H. villosa addition lines showed that chromosomes 1V through 6V gave strong signals in ladders while chromosome 7V escaped detection. In addition to H. villosa, several Triticeae species were identified for a high abundance of the pHvNAU62 repeated sequence, among which Thinopyrum bassarabicum and Leymus racemosus produced the strongest signals. Sequence analysis indicated that the cloned fragment was 292 bp long, being AT rich (61%), and showed 67% homology of pSc7235, a rye repeated sequence. Isochizomer analysis suggested that the present repeated sequence was heavily methylated at the cytosine of the CpG dimer in the genome of H. villosa.It was also demonstrated that pHvNAU62 is useful in tagging the introduced 6VS chromosome arm, which confers a resistance gene to wheat powdery mildew, in the segregating generations.     

五步蛇主要数量性状与排毒量的相关分析

本文首次报道了五步蛇身体主要部位的数量性状与其排毒量的关系。其中我们发现与排毒量有关的部位是头积、体粗、体重、佛指长。     

The conformation of single-stranded nucleic acids tDNA versus tRNA

Conformational analyses using the single-strand-specific nuclease from mung bean and restriction endonucleases have been performed on a series of DNA fragments related to the sequence of the yeast initiator tRNA(Met). Mung bean nuclease cleaves DNA fragments exclusively in some, but not all, single-stranded regions as predicted by RNA secondary structural rules. Comparison of cleavage patterns of yeast initiator tRNA(Met), tDNA(Met) (a DNA oligomer having the sequence of tRNA(Met] and the anti-tDNA(Met) (the complement of tDNA(Met] suggests that the conformation of the three molecules is very similar. Furthermore, both tDNA and anti-tDNA are cleaved by HhaI and CfoI restriction endonucleases at two GCG/C sites which would be in double-stranded regions (the acceptor and dihydrouridine stem), if the two molecules adopt the tRNA cloverleaf structure. On the other hand, minor cleavage products show that the core region, i.e. the extra loop area, is slightly more exposed in tDNA and in anti-tDNA than in tRNA. Therefore, we submit that the global conformation of nucleic acids is primarily dictated by the interaction of purine and pyrimidine bases with atoms and functional groups common to both RNA and DNA. In this view the 2'-hydroxyl group, in tRNA at least, is an auxiliary structural feature whose role is limited to fostering local interactions, which increase the stability of a given conformation.