共查询到20条相似文献，搜索用时 15 毫秒
1.
Applied electric current is transmitted between mammalian glial cells grown in tissue culture. A similar electrical coupling exists between certain neurons as well as between neuroglia and neurons. Although this phenomenon may be a peculiarity of mammalian neural cells maintained in culture, it may, on the other hand, represent a phenomenon with greater neurophysiological significance, a process whereby neurons can become silent. 相似文献
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Labeled strain L cells in suspension tissue culture showed no degradation of protein when maintained in logarithmic growth. Although the protein of these cells was not in dynamic equilibrium, the conclusions cannot be transferred to the intact mammalian organism. 相似文献
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Liquid ethylene oxide, which kills bacteria, yeasts, and molds, was added to a tissue culture medium instead of the usual antibiotics. With some limitations, the use of ethylene oxide sterilization of tissue culture medium has been shown feasible. Data indicate that this method can be used in experiments involving the sterilization of test chemicals and components of the medium used for mammalian cells in culture. 相似文献
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Derivation of oocytes from mouse embryonic stem cells 总被引：3，自引：0，他引：3
Hübner K Fuhrmann G Christenson LK Kehler J Reinbold R De La Fuente R Wood J Strauss JF Boiani M Schöler HR 《Science (New York, N.Y.)》2003,300(5623):1251-1256
Continuation of mammalian species requires the formation and development of the sexually dimorphic germ cells. Cultured embryonic stem cells are generally considered pluripotent rather than totipotent because of the failure to detect germline cells under differentiating conditions. Here we show that mouse embryonic stem cells in culture can develop into oogonia that enter meiosis, recruit adjacent cells to form follicle-like structures, and later develop into blastocysts. Oogenesis in culture should contribute to various areas, including nuclear transfer and manipulation of the germ line, and advance studies on fertility treatment and germ and somatic cell interaction and differentiation. 相似文献
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Microcloning and replica plating of mammalian cells 总被引：2，自引：0，他引：2
J A Robb 《Science (New York, N.Y.)》1970,170(960):857-858
A technique for cloning single mammalian cells has been developed by means of a microculture method (0.010 milliliters per culture). A technique of replica plating has also been developed for use with clones of single cells in microcultures; this technique permits the screening of desired properties of many clones simultaneously before the growth of stock cultures. With these techniques an investigator can with limited budget, space, and personnel perform research using tissue culture systems. 相似文献
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Immunization of normal mouse spleen cell suspensions in vitro 总被引：43，自引：0，他引：43
Dissociated cells from the spleens of unimmunized mice were cultured with and without various mammalian erythrocytes. Spleen cell suspensions cultured with heterologous red cells developed levels of hemolytic plaque-forming cells only one log(2) less than those seen in vivo. The reaction is specific for the in vitro immunizing erythrocytes. Antibody was demonstrated in the culture fluids. 相似文献
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An experiment is described suggesting that the glia cells in the mammalian cerebral cortex are capable of developing electric responses to direct stimuli. When hyperfine microelectrodes were pushed into the cortex of a cat, slow, reversible potential variations were recorded which resembled the "electric responses" from the glia cells in tissue culture. 相似文献
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Penetration of somatic mammalian cells by sperm 总被引：3，自引：0，他引：3
Penetration of somatic mammalian cells by spermatozoa occurred after simple admixture in culture. With sperm labeled in vivo, autoradiography revealed incorporation of DNA into nuclei of recipient cells, indicating release of DNA after entrance by sperm. This system provides a new approach to study the molecular biology of information transfer and of haploid gene expression. 相似文献
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High-frequency C-type virus induction by inhibitors of protein synthesis 总被引：16，自引：0，他引：16
When inhibitors of protein synthesis are added to BALB/c mouse cells in culture, induction of naturally integrated C-type RNA virus occurs in a high percentage of cells. The action of protein synthesis inhibitors differs from that of halogenated pyrimidines, another class of virus inducers, in their effects on biologically distinguishable viruses. The use of such inhibitors to study integrated virus expression provides a means for studying gene regulation in mammalian cells. 相似文献
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Most mammalian somatic cells are thought to have a limited proliferative capacity because they permanently stop dividing after a finite number of divisions in culture, a state termed replicative cell senescence. Here we show that most oligodendrocyte precursor cells purified from postnatal rat optic nerve can proliferate indefinitely in serum-free culture if prevented from differentiating; various cell cycle-inhibitory proteins increase, but the cells do not stop dividing. The cells maintain high telomerase activity and p53- and Rb-dependent cell cycle checkpoint responses, and serum or genotoxic drugs induce them to acquire a senescence-like phenotype. Our findings suggest that some normal rodent precursor cells have an unlimited proliferative capacity if cultured in conditions that avoid both differentiation and the activation of checkpoint responses that arrest the cell cycle. 相似文献
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Large-scale cell culture in biotechnology 总被引：2，自引：0，他引：2
The purpose of this article is to review the current state of large-scale cell culture in terms of its applications, problems, and potential. Because of the commercial and proprietary nature of most large-scale cell culture processes, this review does not contain many detailed scientific results although an attempt is made to address some key issues and findings. Much of this summary deals with processes having an established, commercial track record but some attention is given to more recent innovations with interesting potential applications. Reference is made to plant cell culture but the main emphasis is on mammalian cells. 相似文献
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Nicotinic antagonists enhance process outgrowth by rat retinal ganglion cells in culture 总被引：2，自引：0，他引：2
S A Lipton M P Frosch M D Phillips D L Tauck E Aizenman 《Science (New York, N.Y.)》1988,239(4845):1293-1296
Functional nicotinic cholinergic receptors are found on mammalian retinal ganglion cell neurons in culture. The neurotransmitter acetylcholine (ACh) can be detected in the medium of many of these retinal cultures, after release presumably from the choline acetyltransferase-positive amacrine cells. The postsynaptic effect of endogenous or applied ACh on the ganglion cells can be blocked with specific nicotinic antagonists. Here it is shown that within 24 hours of producing such a pharmacologic blockade, the retinal ganglion cells begin to sprout or regenerate neuronal processes. Thus, the growth-enhancing effect of nicotinic antagonists may be due to the removal of inhibition to growth by tonic levels of ACh present in the culture medium. Since there is a spontaneous leak of ACh in the intact retina, the effects of nicotinic cholinergic drugs on process outgrowth in culture may reflect a normal control mechanism for growth or regeneration of retinal ganglion cell processes that is exerted by ACh in vivo. 相似文献
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Glial cell diversification in the rat optic nerve 总被引：43，自引：0，他引：43
M C Raff 《Science (New York, N.Y.)》1989,243(4897):1450-1455
A central challenge in developmental neurobiology is to understand how an apparently homogeneous population of neuroepithelial cells in the early mammalian embryo gives rise to the great diversity of nerve cells (neurons) and supporting cells (glial cells) in the mature central nervous system. Because the optic nerve is one of the several types of glial cells but no intrinsic neurons, it is an attractive place to investigate how neuroepithelial cells diversify. Studies of developing rat optic nerve cells in culture suggest that both cell-cell interactions and intrinsic cellular programs play important parts in glial cell diversification. 相似文献
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High efficiency DNA-mediated transformation of primate cells 总被引：156，自引：0，他引：156
Tissue culture cells from several mammalian species, including three primate lines, were transfected with recombinant vectors carrying Escherichia coli xanthine-guanine phosphoribosyltransferase or Tn5 aminoglycoside phosphotransferase dominant selectable markers. Human HeLa and SV40-transformed xeroderma pigmentosum cells exhibited stable transformation frequencies of at least 10(-3) (0.1 percent). CV-1, an African green monkey kidney cell line, could be stably transformed with the exceptionally high frequency of 6 X 10(-2) (6 percent). 相似文献
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鱼类肝细胞分离与原代培养技术已有30多年的历史,目前已有40多种鱼的肝细胞被分离、培养并用于各种研究中。主要讨论鱼类肝细胞的分离与培养方法以及不同条件对细胞生理的影响;概括鱼类肝细胞体外培养在生理学、环境毒理学和药理学等方面的应用研究,旨在为建立更多的鱼类肝细胞原代培养模型并应用于相关的研究领域提供参考依据。 相似文献
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The protective antigen moiety of anthrax toxin translocates the toxin's enzymic moieties to the cytosol of mammalian cells by a mechanism that depends on its ability to heptamerize and insert into membranes. We identified dominant-negative mutants of protective antigen that co-assemble with the wild-type protein and block its ability to translocate the enzymic moieties across membranes. These mutants strongly inhibited toxin action in cell culture and in an animal intoxication model, suggesting that they could be useful in therapy of anthrax. 相似文献
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Buffer combinations for mammalian cell culture 总被引：30，自引：0，他引：30
H Eagle 《Science (New York, N.Y.)》1971,174(8):500-503
The growth and metabolism of cultured mammalian cells are markedly affected by the pH variation in ordinary hicarbonate-buffered media (pH 8.0 to 6.9). Those pH swings can be reduced and the pH of the culture can be stabilized as desired in the range pH 6.4 to 8.3 by appropriate combinations of two or three organic buffers, each at 10 to 15 millimolar, in conjunction with phosphate and bicarbonate. The initial alkalinization in sparse cultures is then minimized, and the metabolic acidificatiotn in 24 hours is usually less than 0.4 pH unit except in heavy cultutres. 相似文献