大豆下胚轴线粒体产生超氧物自由基的效率

大豆下胚轴线粒体在呼吸基质存在下,显著地增加了肾上腺素氧化速率,这种氧化速率能为外源SOD抑制,表明线粒体呼吸时产生分子氧的单电子还原成O_2(?)。亚线粒体颗粒产生O_2(?)的效率略高于线粒体。大豆下胚轴线粒体吸链内O_2(?)的产生为NADH所支持并与交替途径无关。表明分子氧单电子还原的部位可能是NADH-黄素蛋白和UbQ-Cyt.B。     

Cross-reactive idiotype family observed in the phthalate-specific B cell repertoire of adult BALB/c mice: diversity of IgM compared with IgG monoclonal anti-phthalate antibodies

A highly conserved clonotype has been identified within the repertoire of B cells specific for the negatively charged hapten phthalate. The prototype of this phthalate-specific clonotype is a primary-response hybridoma (2E9) that produces a mu,kappa anti-phthalate antibody. The 2E9 monoclonal antibody was found to share idiotypic determinants with several other independently-derived mu,kappa and gamma 1,kappa anti-phthalate monoclonal antibodies and with a significant proportion of conventional anti-phthalate antibodies derived from all of the BALB/c mice immunized with phthalate-keyhole limpet hemocyanin. Competitive RIA analysis of the 2E9 idiotypic relatedness between primary and secondary response antibodies was consistent with the hypothesis that the primary response mu,kappa antibodies represent a conserved germ-line product, whereas the secondary response to gamma 1,kappa antibodies reflect somatic variants of the 2E9 clonotype. Further analysis with a site-specific anti-idiotype reagent suggests that the idiotypic differences between mu,kappa and gamma 1,kappa monoclonal antibodies occur at positions outside of the combining site. Fine specificity analysis of the monoclonal antibodies expressing the 2E9 cross-reactive idiotype (CRI) also supports this hypothesis. Seven to 35% of the anti-phthalate antibodies after a single immunization with phthalate-KLH and 1 to 10% of the antibodies after a second immunization express the 2E9 CRI. The 2E9 CRI was also found in several other strains of mice, and its expression was associated exclusively with anti-phthalate antibodies.     

Minor and trace sterols in marine invertebrates 55. The isolation, structure elucidation and synthesis of ergosta-5, 24(28), 25-trien-3 beta-ol

The isolation, structure determination and synthesis of ergosta-5, 24(28), 25-trien-3 beta-ol, as well as the synthesis of its 28-14C analog--a possible biosynthetic precursor of several marine sterols--is described.     

猕猴(Macaca mulatta)主动脉弓的分支类型

随着心血管系统研究的进展和猿猴在医学中的广泛应用,猴主动脉弓分支的情况引起人们的重视。虽然张胜泉等（1974）对猕猴的心脏冠状动脉的解剖学作过调查,但有关主动脉弓分支的资料很少。为此,我们进行了本题研究,以供参考。     

湖南土家族的体质特征

以20至69岁的湖南土家族人为观察测量对象,根据1392人(男896,女496)的身高,1038人(男668,女370)的头部测量,364人(男235,女129)的五官测量和观察结果,分析该民族的体质特征,并与国内其他民族相比较。     

Serum beta 2 microglobulin in adult myeloid acute leukemias

Serum beta 2 microglobulin levels, measured by radioimmunoassay (Phadebas test), were found increased in acute myeloid leukemias at diagnosis. Serum beta 2 microglobulin levels were significantly higher in patients with monocytic leukemias (13 patients, M4-M5 FAB classification) than in those with other cytological types (18 patients). Beta 2 microglobulin levels at diagnosis were correlated with serum lysozyme levels, but they were not correlated with blood blast counts, serum LDH and ferritin levels. 195 serum beta 2 microglobulin measurements were made serially in 30 patients with acute myeloid leukemias in first remission. Compared to values at diagnosis, beta 2 microglobulin levels in remission were significantly decreased. Out of 30 patients in remission 12 had increased serum beta 2 microglobulin levels (greater than 3 mg/l). Serial measurements were not predictive for relapses.     

Virion orientation in cubic crystals of the human common cold virus HRV14

A new cubic crystal form (a = 445.1 A) of space group P23 is reported for human rhinovirus R14. There are four particles per unit cell, each situated on a crystallographic 3-fold axis. The orientation of these particles has been determined with a rotation function and their approximate positions have been derived from a Patterson map. The crystals diffract to at least 2.8 A resolution. Limitations to the possible surface features of the virus are set by a comparison of the cubic and orthorhombic crystal forms.     

Nonrandomness of point mutation as reflected in nucleotide substitutions in pseudogenes and its evolutionary implications

Summary We have obtained a revised estimate of the pattern of point mutation by considering more pseudogene sequences. Compared with our previous estimate, it agrees better with expectations based on the double-strand structure of DNA. The revised pattern, like the previous one, indicates that mutation occurs nonrandomly among the four nucleotides. In particular, the proportion of transitional mutations (59%) is almost twice as high as the value (33%) expected under random mutation. The same high proportion of transitions is observed in synonymous substitutions in genes. The proportion of transitional changes observed among electrophoretic variants of human hemoglobin is about the same as that predicted by the revised pattern of mutation. We also show that nonrandom mutation increases, by about 15%, the proportion of synonymous mutations due to single-nucleotide changes in the codon table, and increases, from 10% to 50%, the rate of synonymous mutation in the seven genes studied. However, nonrandom mutation reduces (by about 10%) the proportion of polar changes among nonsynonymous mutations in a gene. As far as single-nucleotide changes (in the codon table) are concerned, nonrandom mutation only slightly favors relatively conservative amino acid interchanges, and has virtually no effect on the proportions of radical changes and nonsense mutations.     

三种核型多角体病毒核酸同源性的研究

用分子杂交技术研究了黑点银纹夜蛾(Arqyrogramma agnata Stgr,)单粒包埋型核型多角体病毒(简称A,A,SNPV),斜纹夜蛾(Prodenia litura)多粒包埋型核型多角体病毒(简称PL MNPV)以及用A,A,SNPV感染斜纹夜蛾幼虫所获得的多粒包埋型核型多角体病毒(暂称PoI MNPV)三种病毒核酸的同源性,用SDS-Tris酚法分别提取病毒核酸,用内切酶Eco RⅠ酶解,比较了病毒核酸的酶解图谱及分子量,用〔α-~(32)P〕dATP标记的三种病毒核酸Eco RⅠ酶解片段作探针,分别与各病毒核酸的Eco RI酶解片段杂交,结果表明PoI MNPV与PL MNPV的病毒核酸同源,而A,A,SNPV DNA不与PoI MNPV DNA、PL MNPV DNA杂交,无同源序列。     

In vitro lipid oxidation modifies proteins and functional properties of sarcoplasmic reticulum

Changes in protein and fatty acid compositions of flounder sarcoplasmic reticulum during NADH plus ascorbate-dependent lipid peroxidationin vitro were related to the ability of the sarcoplasmic reticulum to sequester Ca⁺². Progressive accumulation of high-molecular-weight protein components occurred concomitantly with loss of Ca⁺²-sequestering activity. Part of this polymerized protein may be the dimer or trimer of Ca⁺², Mg⁺²-ATPase. Loss in Ca⁺², Mg⁺²-ATPase protein could account for over 60% of the polymerized protein. Rate of loss of polyunsaturated fatty acids was C22:6>C20:4>C20:5>C22:5. Loss of polyunsaturated fatty acids and accumulation of thiobarbituric acid-reactive substances occurred concomitantly with protein polymerization.