B淋巴细胞在多向造血祖细胞生长中的地位

小鼠骨髓细胞在体外培养中,加入用流式自由电泳法分离所得的高纯度正常B淋巴细胞,可使多向祖细胞(CFU-mix)集落增加至5倍;加入小鼠B淋巴瘤细胞株的条件培基(M_(12.4.1)-CM)时,CFU-mix数也可增加至4倍。单集落形态学分析结果表明M_(12.4.1)-CM可加强CFU-GEMm及p-BFU-E等早期造血祖细胞的增殖与分化。小鼠高纯度B细胞样品在体外培养中加入1000 rad照射的骨髓细胞可出现CFU-mix集落,如果再加入适量的小鼠肺条件培基,则CFU-mix数量比对照大15倍,其集落性质为CFU-GEMm,GMm及p-BFU-E。在此培养中加不同稀释度抗小鼠IgM血清,结果CFU-mix的产率与抗IgM血清的浓度成直线反比关系,当加入1:10抗小鼠IgM血清时,CFU-mix为0。作者假设在一定培养条件下,IgM阳性的部分B细胞可返祖转化为CFU-mix。     

纪念蒋英教授

蒋英教授是著名的植物分类学家。他从事中国夹竹桃科、萝藦科、番荔枝科植物的专门研究和教育事业有五十四年历史,为祖国科学事业奋斗一生,作出了重大贡献。本文详细地介绍了他的生平、艰苦创业的经过、严谨治学精神、培养人才的经验,并总结了他一生的科研成就和八十多篇著作名录,供后人参考。     

Immunocytochemical diagnosis of acute leukemia with pleural involvement

Cytologic examination of the pleural effusion from a patient with acute leukemia, leukocytosis and bleeding revealed the presence of many leukemic cells, "lymphocytes" and erythrocytes. The significance of these cellular changes was investigated by simultaneous study of blood and effusion leukocytes by morphologic, cytochemical and immunochemical methods. Both the leukemic blasts and the "lymphocytes" in the effusion and the blood were found to be neoplastic and contained antigens characteristic of both myeloid cells (OKM-1) and lymphoblasts (C-ALLA, common acute lymphoblastic leukemia antigen). These results, when analyzed in the context of the clinical findings, were indicative of acute leukemia with pleural involvement. Such a clinically oriented approach may further enhance the potential of cytodiagnosis in patients with serous effusions.     

Chemical transformation of eremofortin C into PR toxin.

The natural products of both eremofortin C (EC) and PR toxin are secondary metabolites of Penicillium roqueforti. Because the chemical structures of EC and PR toxin are closely related to each other and differ only by a hydroxyl functional group in EC and an aldehyde functional group in PR toxin at the C-12 position, the chemical transformation of EC into PR toxin was investigated. Oxidation with a chromic anhydride-pyridine complex was found to be the most satisfactory method.     

Structure of an antifreeze polypeptide and its precursor from the ocean pout, Macrozoarces americanus

Serum antifreeze polypeptides (AFP) from Newfoundland ocean pout have been resolved by ion exchange chromatography and reverse phase high performance liquid chromatography into at least 12 components. The protein sequences of three of the AFP were determined using a combination of protein Edman degradation and cDNA sequencing. The AFP precursor protein encodes for a preprotein of 87 amino acids with no obvious prosequences. Two of the AFP (SP1-A and SP1-C) were separate gene products with minor amino acid sequence differences. The protein structure of SP1-C precursor is MKSVILTGLLFVLLCVDHMTASQSVVAT QLIPINTALTPAMMEGKVTNPIGIPFAEMSQIVGKQVNTPVAKGQTLMPNMVKTYVAGK. The third AFP (SP1-B) is a post-translation modification product of SP1-C. These experiments indicate that the ocean pout AFP are a multigene family with protein structure different from any other known polypeptide antifreezes.     

Comparative research on erythrocyte anionic adenosine triphosphatase in vertebrates

Studies have been made on the level of activity of anion ATPase and its sensitivity to anions in erythrocytic membranes from fishes, amphibians, reptiles, birds and mammals. Significant variations in these properties of the ATPase were found among the species investigated. Protein composition of erythrocytic membranes was also investigated by means of disc-electrophoresis in polyacrylamide gel in men, rabbit, rat, mouse, hamster, tortoise, crow and starling.     

Metabolic inhibition of size-fractionated marine plankton radiolabeled with amino acids,glucose, bicarbonate,and phosphate in the light and dark

The effects of various metabolic inhibitors (dichlorophenyl dimethylurea, chloramphenicol, cycloheximide, carbonyl cyanide m-chlorophenyl hydrazone) on the accumulation of radiolabeled substrates (amino acids, glucose, bicarbonate, phosphate) by size-fractionated marine microbial plankton from the Sargasso Sea and the eastern Canadian arctic were studied in time-course fashion during experimental incubations either exposed to or shielded from ambient solar radiation. Picoplankton accounted for 65% of the organic substrates and phosphate accumulated by the assemblages. The rate of organic substrate accumulation was stimulated by solar radiation in some cases but inhibited in other cases. Presumably, stimulation and inhibition co-occur and the measured response is the net result arising from these counteracting tendencies. Approximately 40% of H¹⁴ CO₃ ^– accumulation in the Sargasso Sea was associated with the picoplankton. The insensitivity of picoplankton¹⁴C-labeling to cycloheximide suggested active prokaryotic photosynthesis rather than heterotrophic assimilation of¹⁴C-labeled algal photosynthates as the route of labeling. The usefulness of some inhibitors was restricted in this study because of inconsistent correlations between the intended primary metabolic effect and the measured ecological response within the duration of the experiment.     

高等植物叶片中的硝酸还原酶活性稳定因子

从小麦、油菜、浮萍、番茄、烟草的叶片中分离得到NR-SF。不同植物材料中NR及NR-SF能起交叉反应;不同NR-SF影响NR酶动力学性质相同;不同NR-SF的凝胶电泳谱带显示蛋白和糖蛋白性质。NR-SF广泛存在于植物细胞中。     

Somatic embryogenesis and plantlet regeneration in the soybean Glycine max

A tissue culture procedure for the regeneration of somatic embryos and plantlets from somatic cells of the soybean Glycine max is described. Bean pods of soybean cv. TGM119 were immersed in liquid nitrogen for 20 minutes. Young embryos were excised from the immature seeds and cultured to form calli. Calli grown from the young embryos were incubated in liquid culture for two weeks. The liquid suspension culture was filtered to obtain single cells. The soybean cells were cultured for one month in a liquid medium in hanging drop cultures for development into proembryoids. The proembryoids were maintained on a solid growth medium for 40 days. The resultant callus tissue was transferred into MS media containing selected combinations and concentrations of 2,4-Dichlorophenoxyacetic acid, Naphthaleneacetic acid, Kinetin, Benzyladenine and Indoleacetic acid. In the presence of Benzyladenine (0.2 mg/l) and Indoleacetic acid (0.01 mg/l), globular and heart shaped somatic embryos were formed on the surface of the calli. Calli containing somatic embryos were transferred into liquid medium and incubated under low light conditions. After six months further incubation, more than 1,000 plantlets and a large number of somatic embryoids at various developmental stages were obtained per flask.Abbreviations KT kinetin - CM coconut milk - BA benzyladenine - NAA napthalene acetic acid - IAA indole acetic acid - 2,4-D 2,4 dichlorophenoxy acetic acid - MS Murashige and Skoog medium     

关于植物核型分析的标准化问题

近年,我国的植物染色体研究工作,进展较快,并取得了显著的成绩。但在研究工作中仍存在一个迫切需要解决的问题,即核型分析的标准化问题。由于国际上尚无植物核型分析的共同标准,因此,有关染色体的统计、测量、命名、图表格式等等,各人所采用的方法和标准也不尽相同。这种状况,对核型资料的比较分析以及对研究结果的评价,都带来不便。有鉴于此,1984年8月在辽宁兴城召开的第一届全国植物染色体学术讨论会上,李懋学和陈瑞阳联名作了“关于植物核型分析的标准化问题”的报告,经过