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91.
综述了近年来有关利用基因转移技术修饰肿瘤细胞制备肿瘤基因工程疫苗的最新研究进展,着重阐述了逆转录病毒载体介导的基因转移及其安全性;归纳了目前可用于肿瘤基因工程疫苗的各种目的基因的特点及作用并对这类肿瘤疫苗制备过程中所存在的问题进行了分析. 相似文献
92.
Biological activities of chemically synthesized analogues of the nonreducing sugar moiety of lipid A 总被引:12,自引:0,他引:12
M Matsuura Y Kojima J Y Homma Y Kubota A Yamamoto M Kiso A Hasegawa 《FEBS letters》1984,167(2):226-230
Adriamycin-Fe3+ complex catalyzes the formation of hydroxyl radical from hydrogen peroxide but the DNA-adriamycin-iron ternary complex is much more effective. 11-Deoxyadriamycin, which shows no spectral evidence of complex formation with iron, was ineffective. The generation of hydroxyl radical by adriamycin-Fe3+ complex in the presence of DNA correlates with its ability to cleave DNA. Hydroxyl radicals are thus implicated as the reactive oxygen species involved in the DNA damage caused by the adriamycin-Fe3+ complex. 相似文献
93.
G. M. S. van Slogteren P. J. J. Hooykaas R. A. Schilperoort 《Plant molecular biology》1984,3(6):333-336
Summary A shooty tumor induced by a shooter mutant of an octopine strain of Agrobacterium tumefaciens was cloned. One clone obtained (TS038) behaved aberrantly in that it grew as a shooty tumor tissue on phytohormone free medium, but did not contain octopine synthase activity. In line TS038 the genes for octopine synthase and for the enzymes involved in agropine and mannopine synthesis were present, but were not transcribed. However, the above genes became active in TS038 tumor shoots after grafting as well as after treatment with the hypomethylating agent 5-azacytidine. After an unusually long incubation period in the growth cabinet shoot cultures appeared to have developed small shoots from the top of the leaves. This unusual form of differentiation was found to be accompanied by the induction of octopine synthase activity. 相似文献
94.
John C. Angello Howard L. Hosick 《Biochemical and biophysical research communications》1982,107(3):1130-1137
Multicellular aggregates of tumorigenic mouse mammary epithelial cells contain a hyaluronate-rich matrix, both at the aggregate periphery and within the growing spheroid. It is proposed that the establishment of a hyaluronaterich matrix is essential to spheroid growth in vitro, and that the spheroid is a good model system for analysis of this aspect of early tumor development. 相似文献
95.
W.James Nelson Constantin E. Vorgias Peter Traub 《Biochemical and biophysical research communications》1982,106(4):1141-1147
A new method is described for the purification of the intermediate filament protein vimentin from Ehrlich ascites tumor cells using single-stranded DNA-cellulose affinity chromatography. The procedure is rapid and allows the large scale isolation of the protein. Partial characterization of vimentin shows that it has a molecular weight of 58000 and an apparent pI of 5.3. It can be degraded by the vimentin-specific, Ca2+-activated proteinase which results in the production of a characteristic set of degradation products. The vimentin also cross-reacts with the intermediate filament protein monoclonal antibody, α-IFA. 相似文献
96.
Thomas E. Gray David G. Thomassen Marc J. Mass J. Carl Barrett 《In vitro cellular & developmental biology. Plant》1983,19(7):559-570
Summary A cell culture system is described for the growth of rat tracheal epithelial (RTE) cells at clonal density. The system uses
normal, early passage RTE cells grown on feeder layers of lethally irradiated 3T3 cells. The RTE cells have a high colony
forming efficiency (5 to 10%) in culture, can be passaged up to 5 times, and are capable of more than 20 cumulative doublings
per colony forming cell. The epithelial nature of the cells was confirmed by cell and colony morphology, immunoperoxidase
staining of intracellular keratin, and cellular ultrastructural studies. The cytotoxic response of RTE cells to a variety
of carcinogens, including a direct acting chemical carcinogen, a physical carcinogen, and a series of polycyclic aromatic
hydrocarbons, was quantitated. A linear decrease in the logarithm of survival was observed with increasing doses ofN-methyl-N′-nitro-N-nitrosoguanidine (MNNG), γ-irradiation, 7,12-dimethylbenz(a)anthracene, and a diol-epoxide of benzo(a)pyrene. No toxicity was observed after treatment with benzo(a)pyrene or 3-methylcholanthrene over the concentration range examined. In contrast, phorbol ester tumor promoters stimulated
cell growth markedly. Based on these and other studies, the RTE cell culture system represents a model system that will be
useful for quantitative studies of epithelial cell growth, differentiation, and carcinogenesis. 相似文献
97.
Imre Mezö János Seprödi Judit Érchegyi István Teplán Magdolna Kovacs Bela Flerkó 《Peptides》1983,4(2):149-151
Inhibitory analogues of luteinizing hormone-releasing hormone (LH-RH) were prepared with formyl-D-Trp1, acetyl-D-Trp1, valeryl-D-Trp1, tartaryl-D-Trp1, diacetyl-tartaryl-D-Trp1, acetyl-Gly1, and acetyl-Sar1 successively replacing the position one in the analogue [D-Trp1, D-p-Cl-Phe2, D-Trp3, D-Phe6, D-Ala10]-LH-RH. The formyl-D-Trp1 and acetyl-D-Trp1 analogues yielded 100% blockade of ovulation at the 10 μg dose; the others were less potent and inhibited ovulation at the 50 μg dose. The inhibitory potency seems to correlate with the polarity of the acyl group. 相似文献
98.
本文根据MTT只能被活的增殖细胞中线粒体切断形成紫色甲(?)的原理,测定了8—甲氧基补骨脂素(8—MOP)对体外培养人癌细胞系HCT、KB和BEL细胞的光敏灭活作用。结果表明,8—MOP和UVA光照对这几种人癌细胞有肯定的灭活作用,该作用与8—MOP剂量和光照时间以及细胞种类有关;MTT法可以作为光敏剂活性检测的一种快捷方法。 相似文献
99.
转移及非转移肿瘤移植后615小鼠血液流变学变化的研究 总被引:1,自引:0,他引:1
血道高转移瘤株FC、淋巴合并血道高转移瘤株U14、淋巴道高转移瘤株H22、非转移瘤株P615分别接种于336只纯系近交615小鼠.不同时间取血并处死动物,进行组织学及血液流变学检查.将转移瘤发展过程分为潜伏期、侵袭期、转移早、中、晚期,非转移瘤发展过程分为潜优期、增殖期、囊腔形成期及中心坏死期.本实验结果显示,不同转移能力及途径肿瘤发展的不同时期血液流变学变化规律不同,因而表明肿瘤侵袭、转移与血液流变学变化之间存在互为因果的紧密关系.其临床诊断及治疗意义被讨论. 相似文献
100.
D. Needham 《Cell biochemistry and biophysics》1991,18(2):99-121
Studies that examine the shear- and abrasion-sensitivity of proliferating cells are important in order to understand the behavior
of hybridoma cells in bioreactor culture and metastasizing cancer cells in the bloodstream. Little is known about the link
between morphology, structure, and mechanical properties of a given cell line, especially with respect to variations throughout
the cell cycle. In our experiments with GAP A3 hybridoma cells, distinct cell morphologies were identified and correlated
with phases of the cell cycle by video microscopic observation of synchronized cells, and of individual cells that were followed
throughout their cell cycle. Micropipet manipulation was used to measure the geometrical (cell volume) and mechanical (apparent
cell viscosity) properties of single cells. As the cell cycle progressed at 37°C, an increase in cell volume from 1400 μm3 to 5700 μm3 was accompanied by an increase in apparent cell viscosity from 430 poise to 12,000 poise, consistent with an accumulation
of more cytoplasmic material in the “older” cells. Hybridomas are representative of the various leukemias derived from hemopoietic
cells, and even though as a whole, they appeared to be rather shear-insensitive, the wide range of property values demonstrates
that a given cell line cannot be characterized by a single value for any one property, and that properties must be related
to the cell cycle when considering proliferating cells. It is interesting to see if distinct stages in the metastatic sequence
of events might correlate with any of these physical features of the cell cycle, irrespective of cell type or cell line. For
example, the cytokinetic doublet could represent a fragile structure that may fail and produce cell death under fluid-shear
conditions that would not affect the cells at any other stage in the cell cycle. Identifying such cell cycle-dependent features
in metastasizing cancer cells could lead to a better understanding of the metastatic process and to possible clinical treatments
directed at making cells more shear- and abrasion-sensitive, and therefore, more likely to be killed by the natural hydrodynamic
forces of the circulatory system. 相似文献