Transformation of Tobacco, Tomato, Potato, and Arabidopsis thaliana Using a Binary Ti Vector System

Using a binary tumor-inducing (Ti) plasmid vector system, several plant species were transformed with a kanamycin resistance marker (neomycin phosphotransferase gene). Four Nicotiana species, seven tomato cultivars, two potato cultivars, and Arabidopsis thaliana were transformed by the binary vector transformation method. In this method, various plant organ pieces were co-cultivated with Agrobacterium tumefaciens cells carrying the binary vector, pGA472, and a helper Ti plasmid. We have also demonstrated that a wild type Ti plasmid can be used as a helper to obtain a transformed plant.     

体外分化的人体巨噬细胞抑制天然杀伤(NK)细胞的研究

本文继先前工作后,进一步应用正常健康人外周血单个核细胞(PBMNC)经塑料培皿粘附技术把单核细胞分离出来,经培养进一步纯化,随后动态观察培养0,2,4,6和8天的单核-巨噬细胞的形态变化和对新鲜分离同种异基因个体PBMNC中NK活性的影响。实验表明,体外分化6天和8天的巨噬细胞质/核比例和胞浆内空泡显著增加,细胞直径约为0天时的2倍。这些细胞和PBMNC之比为0.5:1时,引起了NK细胞活性的50%以上抑制(4小时~(51)Cr标记K 562肿瘤的同位素释放试验)。这种抑制效应不为过氧化氢酶(Catalase 4000单位/毫升)和前列腺素合成酶的抑制剂(Indom 1×10~(-5)M)所阻断。实验证明,同种异基因个体的NK细胞不能识别巨噬细胞表面抗原,从而排除了巨噬细胞和K562肿瘤抗原竞争的可能性。实验还表明,巨噬细胞对NK活性的抑制是不受HLA约束的。应用高频超声振荡破碎巨噬细胞膜方法和免疫调变技术进一步提示,人体巨噬细胞对NK活性的抑制与巨噬细胞体积无关,而与体外分化所赋有的固有特性和它们分泌的免疫调节分子有关。     

大萼香茶菜丁素的化学结构

从大萼香茶菜叶中又分得一个具有细胞毒活性的新的二萜类化合物,命名为大萼香茶菜丁素(macrocalyxin D)。根据光谱和化学数据鉴定其化学结构为[3]。     

四川自贡大山铺蜀龙动物群——简报Ⅴ 两栖类

本文对扁头中国短头鲵(新属新种) (Sinobrachyops placenticephalus gen. et sp. nov.) 的形态特征和分类位置进行简述.标本得自著名的恐龙化石产地——自贡大山铺,产出时代为中侏罗世.中国短头鲵是目前迷齿类中在地史上最年轻的一个属.它的发现使迷齿类在地球上生存时代的上限推移到中侏罗世.     

高滴度单克隆抗体杂交瘤细胞系获得途径的探讨

为探索获得能分泌较高价单克隆抗体杂交瘤细胞系的途径,比较了用不同免疫方法得到的小鼠脾细胞制备杂交瘤,对其产生有效瘤和高价抗体分泌瘤的影响。用不使小鼠致病的病毒(如NDV)或巳灭活的病毒作为抗原时,以较高浓度加佐剂、长间隔(30天)、多次免疫效果较好。用能使小鼠感染的病毒作为免疫原时,以活病毒的亚致死剂量感染小鼠,取其脾细胞制备杂交瘤,效果最理想。有效杂交瘤产率高,分泌高效价抗体的杂交瘤细胞系也多。探讨了从免疫方法着手,定向研制高价单克隆抗体杂交瘤细胞系的可行性。     

新疆石河子地区印度麻花叶病植株病毒分离物的鉴定

1984年,从新疆石河子农学院实验站印度麻花叶病植株上,分离到一株病毒分离物Sc-1,经汁液摩擦接种试验表明,它可以侵染10种豆科植物和2种藜科植物。在印度麻、蚕豆、豌豆、箭舌豌豆、扁豆、山藜豆、田菁和红三叶草上引起系统花叶,在豇豆上产生局部枯斑和系统花叶,在苋色藜、昆诺藜上表现为系统黄斑。失毒温度为55～60℃,稀释限点10~(-3)～10~(-4),体外保毒期3～4天。可经汁液和蚜虫传播,不通过种子传毒。病毒粒体为线条状,大小为13～15×750nm。光学显微镜检查可见,病叶表皮细胞内形成不定形的内含体。电镜下可见风轮状、环状内含体。分离物Sc-1与菜豆黄色花叶病毒(BYMV)抗血清呈阳性反应。我们将Sc-1归为菜豆黄色花叶病毒(BYMV),且为豇豆株系。     

Population structure and dynamics of Pinus massoniana Lamb. on mount Jinyun,Sichuan, China

Masson Pine (Pinus massoniana Lamb.) is a pioneer in forest succession in the subtropics of East Asia. However, the species persits, though with decreasing abundance, throughout the various successional phases. Agestructure, spatial pattern, density, population biomass, and their dynamics are described for a population in Sichuan, China, on the basis of a census of all individuals in the population while substituting space with time. In the course of succession, the population density increases and its rate of growth decreases until self-thinning starts; during the phase of self-thinning density decrease and continues to decrease even afterwards, but the rate of growth increase markedly after self-thinning has stopped. The development of population biomass (Bp) during the early succession from shrub-grassland to the early stages of mixed pine and broad-leaved forest can be described by a logistic equation. Later, Bp decrease rapidly. These changes are governed partly by inherent biological features of P. massoniana and partly by the invasion, establishment and development of shade-tolerant evergreen broad-leaved trees. Both self- and alien-thinning occur. Soil conditions affect the rates of these processes.     

In vitro growth and differentiation of human kidney tubular cells on a basement membrane substrate

Summary Kidney cortical tubular cells, mainly proximal tubular cells, isolated from human kidney and grown either on a basement membrane substrate in chemically defined medium or on plastic in serum-supplemented medium, had substantial proliferative potential and could be propagated for more than 10 generations or 8 passages before senescence. Basement membrane produced on a plastic substrate by the HR-9 endodermal cell line could replace serum supplementation in promoting tubular cell growth. Tubular cells grown on an HR-9 basement membrane substrate exhibited stable epithelial morphology over an extended period of time; in the presence of 5% serum they differentiated into organized structures such as hemicysts and cell cords. Cells grown on plastic failed to differentiate and gradually degenerated. Tubular cells on HR-9 basement membrane were characterized by densely packed microvilli, abundant rough endoplasmic reticulum and free polysomes, basal cell membrane interdigitations, a well-developed endocytotic apparatus, and conspicuous junctional complexes—all features of the proximal tubular cell. Compared with cells on plastic substrate, there were higher levels of the brush border enzymes γ-glutamyl transpeptidase,l-leucine aminopeptidase, and alkaline phosphatase in cells maintained on an HR-9 basement membrane substrate, further supporting the conclusion that a basement membrane substrate promoted differentiation of tubular cells. These data and morphological observations indicate that a basement membrane substrate can promote growth and both functional and morphologic differentiation of human kidney tubular cells. This work was supported by the Veterans Administration.