Specific binding of antigenic peptides to cell-associated MHC class I molecules

T lymphocytes recognize antigen in the form of peptides that associate with specific alleles of class I or class II major histocompatibility (MHC) molecules. By contrast with the clear MHC allele-specific binding of peptides to purified class II molecules purified solubilized class I molecules either bind relatively poorly or show degenerate specificity. Using photo-affinity labelling, we demonstrate here the specific interaction of peptides with cell-associated MHC class I molecules and show that this involves metabolically active processes.     

Characterization of the rough endoplasmic reticulum ribosome-binding activity.

The rough endoplasmic reticulum membranes of mammalian cells contain specific ribosome-binding sites. A purification to apparent homogeneity of a negatively charged protein (ERp180) of relative molecular mass 180,000 (180 K) was reported which was proposed to function as a rough endoplasmic reticulum ribosome receptor. We report here that ribosome-binding site activity quantitatively solubilized from rough endoplasmic reticulum membranes does not cofractionate with ERp180. By contrast, ribosome-binding site activity fractionates as a much smaller, positively charged protein.     

Genotoxic effects of dithane M-45 on the bone marrow cells of mice in vivo

Genotoxic effects of dithane M-45 were studied on the bone marrow cells of male albino mice (Lacca strain) in vivo. Different doses (30 mg, 40 mg and 300 mg/kg b.wt) of dithane M-45 were injected intraperitoneally and their effects were investigated after time intervals of 1, 2, 5 and 10 days. The chromosomal aberrations observed in the bone marrow cells of male mice after treatment with dithane M-45 were fragments, rings, dicentric chromosomes, terminal chromatid deletions, chromatid gaps and breaks. In addition to these chromosomal aberrations, physiological effects such as uneven stretching of chromatin material, end-to-end chromosomal associations, exchange configurations, clumping, stickiness and centromeric associations were also observed.     

S桶空间的几个性质(Ⅱ)

讨论了S桶空间在归纳限和稠密子空间方面的一些基本性质．     

秋水仙素诱导青虾次级卵母细胞二倍体初探

以青虾卵巢为材料，采用秋水仙素诱导多倍体次级卵母细胞．经滴片试验，确立此实验最佳滴片高度为1．5cm，通过设置5个秋水仙素浓度(0．08～0．40mg／mL)及3个作用时间(6～24h)，观察发生染色体加倍的细胞相对数目．实验结果表明：在使用秋水仙素的浓度为0．08～0．40mg／mL，处理6～24h时都可以获得多倍体卵细胞．在秋水仙素浓度是0．32mg／mL，处理6h可得到最高二倍体突变率(32．58％)．还测试了0．32mg／mL COM作用6h时ATPase活性与生理盐水对照组的变化，结果显示COM会在一定程度上影响细胞的新陈代谢．但是50％左右的成活率表明，这种诱导突变的方法仍具有一定的应用价值．     

易中天《品三国》补正

易中天教授在《品三国》中，把历史唯物主义具体化，提出了评论历史人物和历史事件的三项准则，即：“还原”、“比较”、“分析”。易教授在贯彻这三项原则时也难免有疏漏之处：一、把襄阳、赤壁之战说成曹刘之战不能成立；二、曹操一封信促成孙刘联盟的提法不妥；三、《白衣渡江》引用了《吕蒙传》上有两条错误的史料。     

Hydrobiologische Anstalt Plön der Max-Planck-Gesellschaft zur Förderung der Wissenschaften

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