南岭植物区系地理学研究──Ⅲ．植物区系地理亲缘与区划

南岭山地与相邻地区植物区系具有明显的过渡或替代关系,主要通过亚热带及亚热带亚热带亚洲分布成分与华南南亚热带及亚洲热带地区联系;与华中和华东地区植物区系的联系以亚热带及亚热带至温带分布和中国—日本间断分布成分来沟通;与西南地区植物区系的联系则表现为两地共有的古老和与遗成分区及石灰岩山地区系成分．华夏植物区系,是从古老的华夏植物群逐步发展起来的统一体,在区系分区上应划归为统一的华夏植物界,下分东亚植物区、马来西亚植物区和印度—喜马拉雅植物区。南岭山地植物区系拥有其自身的标志种、特有属和丰富的特有种,在区系分区上可划为完整的南岭植物亚省,下分东南岭植物县、中南岭植物县和西南岭植物县。     

Effects of prostaglandin E2, 16,16-dimethyl prostaglandin E2 and a prostaglandin endoperoxide analogue (U-46619) on gastric secretory volume, [H] and mucus synthesis and secretion in the rat

The effects of orally administered prostaglandin E₂, 16,16-dimethyl prostaglandin E₂ and U-46619, an analogue of the prostaglandin endoperoxide PGH₂, on gastric secretory volume, acid and mucus were studied in the rat. All of the compounds significantly increased the volume of gastric secretion, mucus secretion, measured as N-acetylneuraminic acid and mucus synthesis measured as the incorporation of [³H]-glucosamine into mucosal glycoprotein; however, only PGE₂ and 16,16-dimethyl PGE₂ inhibited acid secretion. U-46619, 1.5 mg/kg provided significant protection against ethanol-induced gastric ulcers, an effect that has been previously shown for the other two compounds. These studies provide additional evidence that prostaglandin induced mucosal protection may by related to an effect on mucus and on stimulation of nonparietal cell gastric secretion. Further study of these parameters may be important in the development of antiulcer drugs for long term clinical use.     

Altered surface glycoproteins in melanoma cell variants with reduced metastasizing capacity selected for resistance to wheat germ agglutinin

Variants of B 16-F 1 mouse melanoma cells selected for resistance to wheat germ agglutinin (WGA) toxicity $\text{in}\text{vitro}$ were found to have undergone a stable surface change correlated both to lectin resistance and reduced metastasizing potential. The surface alteration, as indicated by the increased electrophoretic mobilities of several lactoperoxidase-iodinated cell surface proteins in SDS-PAGE, was restricted to polypeptides able to interact with WGA. The availability of lectin-resistant melanoma cell variants having altered metastasizing behavior provides a promising approach to studies of the role of specific cell surface components in the metastasizing process.     

An H-2 haplotype possibly derived by crossing-over between the (A α A β ) duplex and the E βlocus

The B10.STA62 strain carries the H-2 ^w27 haplotype derived from a wild mouse captured in the vicinity of Ann Arbor, Michigan. Products of two class II loci composing this haplotype, A and A , are serologically, biochemically (by tryptic peptide mapping), and functionally indistinguishable from products controlled by the A ^b and A ^/b genes of the B10.A(5R) strain. In contrast, the polypeptide chain controlled by the third class II locus, E , is different from that controlled by the E ^/b gene. This E ^/w27 chain lacks an antigenic determinant present on the E^b molecule and carries determinants lacking on the E^b molecule, the E ^/b and E ^/w27 peptide maps differ in at least six peptides, and cytotoxic T cells specific for the E ^b chains do not react with B10.STA62 target cells. This great difference between the E ^/b and E ^/w27 chains suggests that the corresponding genes have not been derived from one another by a direct mutational conversion; instead, H-2 ^w27 appears to be a recombinant haplotype derived by crossing-over between the A A duplex and the E locus. This is the first recombinant discovered separating these class II loci.     

Differential phosphorylation of band 3 and glycophorin in intact and extracted erythrocyte membranes

This report presents an analysis of the phosphorylation of human and rabbit erythrocyte membrane proteins which migrate in NaDodSO₄-polyacrylamide gels in the area of the Coomassie Blue-stained proteins generally known as band 3. The phosphorylation of these proteins is of interest as band 3 has been implicated in transport processes. This study shows that there are at least three distinct phosphoproteins associated with the band 3 region of human erythrocyte membranes. These are band 2.9, the major band 3, and PAS-1. The phosphorylation of these proteins is differentially catalyzed by solubilized membrane and cytoplasmic cyclic AMP-dependent and -independent erythrocyte protein kinases. Band 2.9 is present and phosphorylated in unfractionated human and rabbit erythrocyte ghosts but not in NaI- or dimethylmaleic anhydride (DMMA)-extracted membranes. These latter membrane preparations are enriched in band 3 and in sialoglycoproteins. The NaI-extracted ghosts contain residual protein kinase activity which can catalyze the autophosphorylation of band 3 whereas the DMMA-extracted ghosts are usually devoid of any kinase activity. However, both NaI- and DMMA-extracted ghosts, as well as Triton X-100 extracts of the DMMA-extracted ghosts, can be phosphorylated by various erythrocyte protein kinases. The kinases which preferentially phosphorylate the major band 3 protein are inactive towards PAS-1 while the kinases active towards PAS-1 are less active towards band 3. The band 3 protein in the DMMA-extracted ghosts can be cross-linked with the Cu²⁺ -σ-phenanthroline complex. The cross-linking of band 3 does not affect its capacity to serve as a phosphoryl acceptor nor does phosphorylation affect the capacity of band 3 to form cross-links. In addition to band 2.9, the major band 3 and PAS-1, another minor protein component appears to be present in the band 3 region in human erythrocyte membranes. This protein is specifically phosphorylated by the cyclic AMP-dependent protein kinases isolated from the cytoplasm of rabbit erythrocytes. The rabbit erythrocyte membranes lack PAS-1 and the cyclic AMP-dependent protein kinase substrate.     

Cytokinin biochemistry in relation to leaf senescence I. The metabolism of 6-benzylaminopurine and zeatin in oat leaf segments

Journal of Plant Growth Regulation - The metabolism of zeatin and that of 6-benzylaminopurine (BAP) have been compared in oat leaf segments in relation to the markedly differing ability of these...     

黑胸大蠊（Periplaneta fuliginosa）病毒的分离及某些特性

从黑胸大蠊(Periplaneta fuliginosa)自然罹病的虫尸中分离得到一株非包涵体病毒。将病毒悬液均匀拌入无菌饲料并供食154～169日龄黑胸大蠊健康若虫时,能使其感染、发病,死亡率可达98％以上。在电子显微镜下观察时,病毒为球形二十面体颗粒,直径约23nm。病毒悬液具有典型核蛋白紫外吸收光谱。病毒用DNase和RNase处理并经吖啶橙染色、二苯胺和苔黑酚试验及甲醛反应证明:该病毒含有单链DNA。以上特性与细小病毒科的特征有点类似。     

四种中草药对大鼠半乳糖性白内障氧化还原物质及糖类含量的影响

对正常和半乳糖性白内障及给中草药的大鼠晶状体中某些吡啶核苷酸成分、糖类、非蛋白质巯基的含量进行了比较。结果表明,在白内障晶状体中,NADPH及非蛋白质巯基的含量明显低于正常晶状体的,而NADP、半乳糖及半乳糖醇的含量明显高于正常晶状体的;当注射半乳糖的同时分别用黄岑、石斛、菟丝子及玉蝴蝶四种中草药水煎剂灌胃,上述变化为基本恢复至正常晶状体的水平。表明四种中草药对晶状体中的异常生化变化具有阻止及纠正作用。     

壳聚糖固定化木瓜蛋白酶的研究

以壳聚糖为载体,成二醛为交联剂将木瓜蛋白酶固定化。5％戊二醛在4-6℃下处理载体5h,加酶液(3.5mg/mL蛋白,pH7.2)固定12h,活力回收达32％,作用于酪蛋白的半衰期为36天,其表观K_m(酪蛋白)值为0.075％(W/V),溶液酶的K_m值为0.086％;最适pH7.0～7.5,溶液酶为7.0～8.5。固定化酶在pH8.5以下,溶液酶在9.0以下活力稳定。固定化酶在45℃以下,溶液酶在75℃以下稳定。用6mol/L脲洗脱固定化酶4次(5.5h)活力仍有54.5％。用固定化酶处理啤酒浊度比对照下降了1.5-3.7倍,蛋白质含量下降了44％,冷藏(4℃)120天无冷混浊现象发生并保持了啤酒原有风味和理化性状。