链霉菌原生质体种间融合提高细胞分裂素效价的研究

本文报道粉红孢类群的泾阳链霉菌与淡紫灰链霉菌不液化亚种的原生质体种间融合重组的结果。利用单亲灭活和双亲株的遗传标记筛选细胞分裂素的融合子,融合率为 10-4—10-2。在所得的融合菌株中,F1211菌株的CTK效价为292μg/L,F1613的CTK效价为857μg／L,比低产原始亲株提高2—7倍,比高产亲株提高0.3--3.0倍。在电子显微镜下观察到融合过程。     

人肝癌细胞表皮生长因子受体以及佛波酯对它的调度

Using radioligand binding assay, the presence of epidermal growth factor (EGF) receptors in cells of two human liver cancer cell lines, BEL-7402 and SMMC-7721, was demonstrated. The ligand binding data were analyzed by a computer program. The dissociation constants (KD) of the ligand-receptor binding complex at equilibrium for 7402 and 7721 cells were 1.2 nM and 0.8 nM respectively, and their number of EGF receptors per cell were 6.2 x 10(4) and 2.5 x 10(4) respectively. After the treatment of cells with phorbol 12-myristate 13-acetate (PMA), no change either in the affinity or in the number of EGF receptors was found in 7721 cells. However, in the case of 7402 cells, while the number of receptors, like 7721 cells, remained unchanged, the affinity of EGF receptors displayed a time dependent modulation after PMA treatment. It dropped within the first hour to a KD value of 3.0 nM and then gradually returned to the normal control value at 48 hours or even slightly higher than normal (0.95 nM) at 96 hours of treatment. The modulation or down-regulation of EGF receptors by PMA in 7402 cells was paralleled by the simultaneous inhibition of DNA synthesis in these cells as evidenced from their reduction of 3H-TdR uptake. It is not clear what is the basis for the differences found between 7402 cells and 7721 cells in their number of EGF receptors per cell and their responsiveness to PMA treatment. It might be related to their difference in autocrine secretion of alpha-transforming growth factors.(ABSTRACT TRUNCATED AT 250 WORDS)     

成人及新生儿颅骨铜和锌含量的初步研究

本文系用原子吸收光谱法测定了西安地区10例成人尸体和15例新生儿尸体的颅盖骨内Cu和zn的含量。结果求得成人颅骨中Cu正常含量(均数±标准差)为4.48±3.78mg/kg(干组织重);zn为597.05±472.54mg/kg。新生儿颅骨中Cu和zn的含量分别为1.96±0.76mg/kg;1160.38±859.71mg/kg。结果表明,成人颅骨内Cu含量高于新生儿,而成人颅骨内Zn含量显著低于新生儿。     

聚丙烯酰胺板状凝胶的简单干燥方法

我们依据组织逐级脱水的原理,经过摸索得到一种经济简单的凝胶干燥方法,特别是解决了浓度较高(10％—15％)凝胶和3％—25％梯度凝胶的干燥,可将聚丙烯酰胺板状凝胶干燥成一张平整、透明的干胶片,可直接照相或用感光胶片直接印制成负片。现将方法介绍如下:     

一种简单快速的聚丙烯酰胺凝胶电泳染色法——铜染色法

十二烷基硫酸钠-聚丙烯酰胺凝胶电泳(SDSPAGE)作为分离鉴定生物大分子的有效手段已广泛用于分子生物学和医学临床工作,迄今为止,用于该技术的染色法多沿用考马斯亮蓝(CBB)和银染色。但上述两法均有其局限性,如蛋白凝胶染色前须经酸醛固定,不易洗脱且操作繁琐,脱色耗时。最近,Lee等报道一种SDS-PAGE负染色法,利用氯化铜分别与凝胶中     

从凝胶中回收DNA的一种简便方法

从凝胶中回收DNA的方法已见多种报道,其中的电洗脱法较实用,已有几种装置作为商品出售。Wu等的方法无须任何专门设备,而是在DNA电泳区带前方挖槽,槽内嵌半透膜,使样品自凝胶泳入槽内的缓冲液中。该方法说来简单,实际操作却很费劲,尤其在样品数量大或重复操作时,更觉不便。我们按照Wu等的工作原理,制成一种电洗脱器,可使DNA的回收操作变得简单而高效。     

黑龙江桔梗科叶表皮研究

本文对分布在黑龙江省的桔梗料(Campanulaceae)植物叶表皮进行了光学显微镜和扫描电镜方面的观察。发现桔梗科植物的气孔复合体是不规则型的;毛状体是单细胞的,其表面的角质纹饰因类群而异;表皮角质纹饰可用于某些种间的鉴别。