肉瘤-180小鼠体液中抑癌因子的研究

本文报告从肉瘤-180小鼠腹水液中分离出抑癌因子,并将其与艾氏腹水瘤小鼠腹水中的抑癌因子进行比较。结果表明,二者具有相同的生物学特性和理化性质:1.它们均能杀伤不同的癌细胞株,但对正常细胞没有影响;2.经聚丙烯酰胺凝胶电泳,为泳动速率相同的均一多肽。     

人脑胶质细胞瘤核染色质非组蛋白的聚丙烯酰胺凝胶电泳分析

用不连续SDS-聚丙烯酰胺凝胶电泳分析了人脑胶质细胞瘤与正常脑细胞核NHCP电泳图谱。从二者的NHCP电泳结果表明,脑胶质细胞瘤增加了一条表观分子量为3万的蛋白区带;表观分子量为1.75万～6.5万的蛋白区带染色明显加深。染色质紫外吸收光谱也有明显差异。总之,脑胶质细胞瘤核NHCP发生质与量的变化。     

A method for easily customizable gradient gel electrophoresis

Gradient polyacrylamide gel electrophoresis is a powerful tool for the resolution of polypeptides by relative mobility. Here, we present a simplified method for generating polyacrylamide gradient gels for routine analysis without the need for specialized mixing equipment. The method allows for easily customizable gradients which can be optimized for specific polypeptide resolution requirements. Moreover, the method eliminates the possibility of buffer cross contamination in mixing equipment, and the time and resources saved with this method in place of traditional gradient mixing, or the purchase of pre-cast gels, are noteworthy given the frequency with which many labs use gradient gel SDS-PAGE.     

华东地区黑果蝇自然群体同工酶遗传多态的研究

我们用标准垂直板聚丙烯酰胺凝胶电泳和水平板琼脂糖凝胶电泳技术检测了黑果蝇(D.virilis)在合肥、芜湖、九江、南昌、福州、泉州和常州7个自然群体中Est-α、Est-β、Amy、Acph和α-Gpdh 5个座位的遗传变异,发现Est-α、Est-β和Amy 3个座位是高度多态的,Acph、α-Gpdh两个座位则是单态的。根据这5个座位等位基因的频率,我们计算了群体间的遗传距离。综合何朝珍报道的宁波、杭州、南京和洪泽4个群体的结果和我们的结果,我们作出系统树并发现泉州、福州两群体和其他群体在基因频率的分布和遗传距离方面有显著差异;分析显示这种差异与群体间地理隔离有关。     

聚丙烯酰胺微生物降解研究进展

聚丙烯酰胺是一类重要的水溶性高分子聚合物,已广泛应用到工农业生产的各个领域和人们的日常生活中。由于具有良好的理化特性,一直被认为是安全、无毒和稳定的,所以有关其在自然界中的降解及其可能产生毒性的研究在很长一段时期内被忽视。事实上,聚丙烯酰胺在环境中的残留、迁移、降解对环境具有潜在危害性。目前,其应用范围和规模正呈现快速增长趋势,而其研究多集中在其合成和应用方面,对聚丙烯酰胺的降解尤其是生物降解研究极少。     

Thromboxane A3 (TXA3) is formed in human platelets after dietary eicosapentaenoic acid (C20:5 omega 3)

Platelet-rich plasma of subjects, who had ingested cod liver oil containing 10% eicosapentaenoic acid (C20:5 omega 3), the precursor of trienoic prostanoids, was stimulated ex vivo with collagen. Formation of thromboxane B3, the hydrolysis product of non-aggregatory thromboxane A3, from endogenous eicosapentaenoic acid was demonstrated by combined capillary gas chromatography-mass spectrometry. Concomitantly platelet aggregation in platelet-rich plasma upon low doses of collagen and associated thromboxane B2 formation from endogenous arachidonic acid were reduced. We conclude that both the formation of inactive thromboxane A3 as well as the reduction of thromboxane A2 may contribute to the reduced platelet reactivity after dietary eicosapentaenoic acid.     

Electrophoretically silent alleles in a finite population

Summary The expected number of silent alleles in an electromorph is computed for various values of population size (N), mutation rate (u), and sample size (s) under the assumption of no selection. The proportion of alleles undetectable by electrophoresis is higher when Nu is large than when this is small. It is shown that an electromorph of high population frequency has more silent alleles than an electromorph of low frequency if the sample size is the same.     

tRNA-isoleucine-tryptophan composite gene

Transfer-RNA genes in archaea often have introns intervening between exon sequences. The structural motif at the boundary between exon and intron is the bulge-helix-bulge. Computational investigations of these boundary structures in Haloarcula marismortui lead us to propose that tRNA-isoleucine and tRNA-tryptophan genes are co-located. Precise in silico identification of the splice-sites on the bulges at the exon-intron boundaries lead us to infer that a single intron-containing composite tRNA-gene can give rise to more than one gene product.     

Polyaniline/polyacrylamide conducting composite hydrogel with a porous structure

A polyaniline/polyacrylamide composite hydrogel is synthesized, characterized and measured. Fourier transform infrared spectroscopy reveals that partial polyaniline chains have grafted on the nitrogen atoms of polyacrylamide. X-ray diffraction shows that typical polyaniline crystallization is formed in polyaniline/polyacrylamide composite, which is advantageous to increase the electrical conductivity of the composite hydrogel. UV–Vis spectra indicates the formation of high conductive emeraldine polyaniline salt in polyaniline/polyacrylamide composite. Scanning electron microscopy shows a typical porous structure in the composite hydrogel. The polyaniline/polyacrylamide hydrogel has a good conductivity of 0.6 S/cm and good release stability in acidic and neutral conditions.     

Escherichia coli gal K和gpt基因注入小鼠受精卵的研究

含有E.coli galK和gpt基因的重组DNA pPB22用显微注射法导入昆明白小鼠受精卵,经发育,最后得到21只成年小鼠。其中1只小鼠的肝脏显示出E.coli gpt酶活性,但未检测出E.coli galK酶活性。印迹分子杂交表明,外源的pPB 22重组DNA已整合到2只小鼠的染色体上,其中包括那只肝脏中显示E.coli gpt酶活性的小鼠。     

用凝胶电泳发现肝素与染料之间的相互作用

目的:观察肝素与23种染料之间的相互作用.方法:利用淀粉琼脂糖凝胶电泳及聚丙烯酰胺凝胶电泳,观察染料加肝素后电泳行为的变化.结果:淀粉琼脂糖凝胶电泳中染料加肝素后多数结果是泳速变慢,有一些留在原点,也有前移、后退者.二氯荧光素、荧光红、荧光素、甲酚红、苯胺蓝、溴酚蓝、茜素红S、胭脂红、亮绿、氨基黑10B、丽春红G、曙红、苯胺黑、氯酚红加肝素后泳速变慢.亚甲蓝、灿烂甲酚蓝、甲基紫加肝素后电泳留在原点.刚果红、洋红加肝素后电泳变化不明显.四氯荧光素、氯化硝基四氮唑蓝加肝素后电泳荧光看不清.聚丙烯酰胺凝胶电泳中溴酚蓝加入肝素后泳速明显变慢,随着肝素量增加溴酚兰的泳速加快.与淀粉琼脂糖凝胶电泳结果一致,但它的电泳结果更明显.结论:本次所研究的23种染料,几乎都能与肝素发生相互作用,给它们的进一步深入研究打下基础.     

细胞凋亡检测方法的研究进展

细胞凋亡在生命活动中具有重要的地位,多年以来一直都是生命科学领域的研究热点.为了准确、快速的检测细胞凋亡,人们发明了多种方法,并且随着科技的发展和技术的进步,新的检测方法不断涌现.就近年来关于细胞凋亡的一些检测方法进行综述.     

Transamination: An Exercise in Experimental Control

In the light of the misunderstandings detected in the area of water transport a model based on the physical sciences was designed in the form of an animated film. Pupils taught by this means were able to pick their way through the proposed hierarchy of ideas to construct for themselves a shorter (self-consistent) route than that envisaged by the designers. This route formed a useful ‘core’ approach to the topic which would be sufficient for O-level, but would be weak in its predictive properties and form an unsatisfactory base for further study.     

Biochemical systematics of some serranids from Taiwan (Pisces, Serranidae)

An electrophoretic study of genetic variation at 17 loci in ten serranids belonging to three subfamilies (Anthiinae, Epinephelinae and Serraninae) was carried out to assess their systematic relationships. A relationship dendrogram was constructed from the fenetic identities calculated b Nei's method for all pairwise cornarisons. These fishes were divided into three major welldefined groups: Anthiinae, Epinepielinae and Serraninae. Although the relationships among them appear slightly different from that deduced from morphological features; e. g., Serraninae are distant from Anthiinae and Epinephelinae biochemically, but are closer to Antiinae than to Epinephelinae morphologically. However, a tendency for an increase of the genetic distance in higher categories is obvious (Table 5).     

一种PCR酶切克隆目的DNA方法

以PCR扩增克隆survivin启动子为例,根据GenBank报道的序列设计引物,PCR扩增克隆survivin启动子。通过软件在线分析扩增的survivin启动子酶切位点,将扩增与预期的片段大小一致的DNA片段进行酶切,再进行测序。结果表明,采取酶切鉴定PCR产物的方法,可以初步对PCR产物是否正确做出判断。     

不同阶段乙型流行性感冒病毒核酸的聚丙烯酰胺凝胶电泳图

本文应用聚丙烯酰胺凝胶电泳(PAGE),比较了7株不同阶段乙型流感病毒代表株的核酸电泳迁移率,发现不同阶段毒株的PAGE基因图是不同的。这种差别与乙型流感病毒血清学的结果基本相符。     

Cell surface charge. Correlation of partition with electrophoresis

Critical mixtures of aqueous solutions os polymers separate into two or more immiscible phases. Particulate materials distribute in such phase systems generally between one bulk phase and the interface between bulk phases. The distribution is described by a simple partition law, and is qunatitatively determined by, inter alia, the nature of the particle surface, particularly net electrical charge. The partition behaviour of various cells, native or modified by treatment with trypsin, neurominidase or maleic anhydride, correlate strongly with electrophoretic mobility. Partition behaviour and electrophoretic mobility are both dependent upon cell surface charge. Thus, in appropriate conditions, changes in surface charge may be registered as changes in partition.