Glucocorticoid receptor-like antigen in lymphoma cell membranes: correlation to cell lysis

S-49 mouse lymphoma cells undergo lysis when treated with glucocorticoids; the mechanism of this effect is not understood. A protein was detected in the plasma membrane of these cells by means of direct immunofluorescent labeling with a monoclonal antibody to the soluble glucocorticoid receptor. Cellular heterogeneity in the content of this glucocorticoid receptor-like molecule was evident. By immunoadsorption to antibody-coated tissue culture plates, the cells were separated into populations positive (100%) and depleted (38%) for this membrane antigen. Gel electrophoresis, specific immunoblot, and autoradiographic (binding of [3H]dexamethasone mesylate) analysis of the membrane proteins from the membrane antigen-positive group revealed multiple protein bands ranging in size from 85 to 145 kilodaltons. Furthermore, comparison of the glucocorticoid sensitivity of these groups of cells showed complete lysis of the membrane antigen-positive cells and only partial lysis of the antigen-deficient group, which suggests that the lysis response of cells to glucocorticoids is mediated by a glucocorticoid receptor-like molecule located in the plasma membrane.     

Potentiation of glucocorticoid activity by 5 beta-dihydrocortisol: its role in glaucoma

5 beta-Dihydrocortisol potentiated the threshold level (the smallest dose producing a measurable effect) of topically applied cortisol (0.02 percent) and dexamethasone (0.003 percent) in causing nuclear translocation of the cytosolic glucocorticoid receptor in rabbit iris-ciliary body tissue. 5 beta-Dihydrocortisol accumulates in cells cultured from trabecular meshwork specimens from patients with primary open-angle glaucoma, but not in similar cells derived from nonglaucomatous patients. In view of the sensitivity of patients with primary open-angle glaucoma to the effects of glucocorticoids in raising intraocular pressure, this potentiation may be responsible for the steroid sensitivity and for the ocular hypertension seen in this disorder.     

CD158受体表位封闭对急性髓系白血病患者NK细胞杀伤活性的影响

目的 研究急性髓系白血病患者NK细胞CD158受体表位封闭对自身白血病细胞杀伤活性的影响.方法 分离急性髓系白血病患者及健康志愿者外周血NK细胞,以自身白血病细胞及K562细胞为靶细胞,用CCK-8试剂盒检测CD158a、CD158b单克隆抗体封闭前后NK细胞在1：1、5：1、10：1效靶比下对靶细胞的杀伤活性.结果 患者与正常人NK细胞对K562细胞均有高度杀伤活性,且随效靶比增大而增高（P＜0.01）.效靶比为1：1、5：1、10：1时,患者NK胞在封闭前对白血病细胞杀伤活性分别为（1.5±0.3）%、（5.6±0.8）％、（11.8±0.6）%,封闭后分别为（21.8±0.7）％、（38.6±0.9）％、（53.9±1.4）％,各效靶比组封闭前后差异有统计学意义（P＜0.01）.结论 急性髓系白血病患者NK细胞CD158受体表位封闭可提高NK细胞对自身白血病细胞的体外杀伤能力.     

The glucocorticoid receptor: rapid exchange with regulatory sites in living cells

Steroid receptors bind to site-specific response elements in chromatin and modulate gene expression in a hormone-dependent fashion. With the use of a tandem array of mouse mammary tumor virus reporter elements and a form of glucocorticoid receptor labeled with green fluorescent protein, targeting of the receptor to response elements in live mouse cells was observed. Photobleaching experiments provide direct evidence that the hormone-occupied receptor undergoes rapid exchange between chromatin and the nucleoplasmic compartment. Thus, the interaction of regulatory proteins with target sites in chromatin is a more dynamic process than previously believed.     

银杏酚酸杀灭鱼类病原菌和指环虫的研究

提取银杏外种皮中的银杏酚酸,测定了其含量,并对其杀灭鱼类病原菌和指环虫的活性进行了研究。结果表明,分离物中银杏酚酸的总含量为867 m g/g,各单体C15∶1,C17∶1,C13∶0,C15∶0,C17∶2的相对含量分别为499,226,201,32和29 m g/g;银杏酚酸对鱼害粘球菌的最低抑菌浓度(M IC)和最低杀菌浓度(M BC)均为7.81μg/mL,对鳗弧菌、点状产气单胞菌点状亚种、嗜水气单胞菌3株病原菌无明显的抑制效果,其M IC和M BC值均大于1 000μg/mL;银杏酚酸对指环虫的最佳杀虫浓度为1.70 m g/L,48 h杀灭率达95%~100%;其质量浓度为3.5m g/L时试验金鱼开始出现中毒现象,48 h的死亡率为60%。     

不同温度对独蒜兰开花和生长的影响

\t\t\t\t\t目的\t\t\t\t\t以艳花独蒜兰(Pleione aurita)、云南独蒜兰(P. yunnanensis)和黄花独蒜兰(P. forrestii)的休眠假鳞茎为试验材料,研究低温贮藏期间独蒜兰芽发育和生理生化的变化,为独蒜兰属植物的低温贮藏提供参考。\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t方法\t\t\t\t\t将3种独蒜兰贮藏在(4±1) ℃条件,在0、30、60、90、120 d时测定新芽长度、可溶性蛋白含量、SOD活性和POD活性。\t\t\t\t\t\t\t\t\t\t\t\t\t结果\t\t\t\t\t3种独蒜兰假鳞茎在(4±1) ℃低温冷藏60 d后芽开始伸长。艳花独蒜兰假鳞茎中可溶性蛋白含量无明显变化,SOD活性在处理120 d时出现显著降低,POD活性在30~60 d时呈现明显下降,90~120 d再上升。云南独蒜兰和黄花独蒜兰假鳞茎可溶性蛋白呈增加趋势,而SOD活性无明显变化,POD活性在0~30 d时明显下降,30~60 d呈上升趋势。\t\t\t\t\t\t\t\t\t\t\t\t\t结论\t\t\t\t\t艳花独蒜兰、云南独蒜兰和黄花独蒜兰落叶休眠假鳞茎在(4±1) ℃条件贮藏60 d后可进行栽培,POD活性的降低有利于三者新芽的萌动。\t\t\t\t     

Goblet cells in embryonic intestine: accelerated differentiation in culture

If duodenal tissue from 14-day chick embryos is cultured in chemically defined medium, more than twice as many goblet cells appear within 48 hours as in intact embryos during the same time. The increase in goblet cell number is further accelerated by 10(-9) molar thyroxine but is prevented by 10(-6) molar hydrocortisone. The results suggest that differentiation of intestinal epithelium is regulated in part by a circulating inhibitor.     

Junctions between cancer cells in culture: ultrastructure and permeability

Cell junctions between Novikoff hepatoma cells (N1S1-67) growing as small clumps or chains in suspension culture have been studied with ultrastructural, electrophysiological, and dye-injection techniques. Cells within clumps are commonly electrically coupled and can exchange dyes with a molecular weight of 332 to 500. Gap junctions and intermediate junctions are present, whereas true tight junctions and desmosomes are absent or very rare. This system should provide a useful model for studying the properties of "communicating" junctions.     

Sensitivity of culture mammalian cells to streptomycin and dihydrostreptomycin

Cultured mammalian cells killed by streptomycin were essentially unaffected by an identical concentration of dihydrostreptomycin.     

Isoantigenic variants: isolation from human diploid cells in culture

Variant human fibroblast substrains, resistant to a cytotoxic human isoantiserum, were isolated from sensitive strains by repeated exposure to isoantiserum and rabbit complement. The resistant phenotype was stable, apparently occurred at low frequency, and was associated with loss of surface isoantigens.     

Chloramphenicol: effects on mouse myeloma cells in tissue culture

Within 36 hours of being administered, chloramphenicol (50 micrograms per milliliter) inhibits by 50 percent the rate of protein synthesis in mouse myeloma cells grown in suspension culture. Although there is a decrease in the amount of globulin synthesized, the rate of synthesis per cell is unchanged; the observed decrease is traced to the inhibition of cell proliferation caused by chloramphenicol.     

Brain cells in culture: morphological transformation by a protein

One type of elmbryonic rat brain cell having an epithelioid morphology in the monolayer culture can be transformed by brain extract into cells having extensive processes resembling mature astrocytes. The transforming factor is a protein with a molecular weight of 350,000. A partially purified sample showed that it is active at a concentration as low as 1 x 10(-8)M. The transforming actvity is high in adult brains but low in embryonic brains and tumors of the nervous systems.     

鸡热应激及糖皮质激素受体与热休克蛋白相关性的研究

应用＾３Ｈ－Ｄｅｘ放射配体结合的Ｓｃａｔｃｈａｒｄ分析和＾３５Ｓ－蛋氨酸体外标记法分别测定了环境温度４０℃应热应激时,鸡外周血淋巴细胞的糖皮质激素受体的最大结合容量、平均衡角离常数及其热休克白的表达。     

Potentially lethal radiation damage: repair by mammalian cells in culture

Less than optimum conditions with regard to cell division after x-irradiation provide the necessary environment in which mammalian cells can repair potentially lethal radiation damage. The kinetics of repair suggest that, during the repair process, a transient, unstable cellular state occurs which prevents cell division in complete growth medium. The capacity for repair appears to be dependent on cell age.     

Bone cells: a serum-free medium supports proliferation in primary culture

Bone-cells isolated from embryonic rat calvaria increase in number two-to threefold when cultured at high, but not at low, population densities in a serum-free medium that contains albumin. Cultured cells respond to parathyroid hormone and exhibit a marked rise in alkaline phosphatase activity during proliferation, which suggests the progressive differentiation or preferential growth of osteoblast-like cells.     

Replication of human endothelial cells in culture

Investigative studies dealing with the properties and functions of endothelial cells have been hampered because there has been little or no success in the isolation, growth, and passage of individual cells in large numbers. We have developed a system whereby pure cultures of endothelial cells derived from umbilical veins can be subcultured for at least five serial passages. Many facets of endothelial function and interaction can be evaluated with the use of this new adaptive system of isolation and culture.     

Plant "primary perception": electrophysiological unresponsiveness to brine shrimp killing

A test of the "primary perception" hypothesis proposed by Backster in 1968 was made by recording electrical activity from the leaves of Philodendra scandentia while randomly ejecting the contents of micropipettes filled with brine shrimp or distilled water into boiling water. Test conditions conformed to those published by Backster or communicated in personal exchanges. Data were analysed from five experiments, in each of which recordings were made from four plants in the presence of three brine shrimp killings and two control water ejections. Inspection of the data and analysis by two statistical methods revealed no relationship between brine shrimp killing and electrical "responsiveness" of philodendron.     

Neuraminidase activity in hela cells: effect of hydrocortisone

Homogenates of HeLa cells contain neuraminidase activity. This enzyme is particle-bound, and it has a pH optimum of 4.2. Hydrocortisone-regulated cells contain two to three times as much neuraminidase as the corresponding controls. The hydrocortisone treatment also causes an increase in the cell content of beta-glucuronidase and acid deoxyribonuclease.     

Circadian clock in culture: N-acetyltransferase activity of chick pineal glands oscillates in vitro

N-Acetyltransferase activity was measured in organ-cultured chick pineal glands. A circadian rhythm of enzyme activity persisted in cultured glands for up to 4 days. The phase of the rhythm in vitro closely approximates its phase in vivo. These observations demonstrate that the pineal gland of chicks contains (or is) a self-sustained circadian oscillator.     

Differential development of two classes of acetylcholine receptors in Xenopus muscle in culture

Physiological properties of acetylcholine receptors on muscle cells at very early stages of ontogeny were compared with those of cells at later stages. Two changes were observed that contributed to an overall shortening of the mean open time of single-channels. First, there was a shift in the relative proportions of two receptor types with different conductances and mean open times, such that the contribution of receptors with large conductance and short open time increased as development proceeded. Second, there was a sharp reduction in the mean open time of channels having small conductance, with no similar change in channels having large conductance.