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131.
T. Wakabayashi E. F. Korman D. E. Green 《Journal of bioenergetics and biomembranes》1971,2(5-6):233-247
A set of six biological membranes has been examined electron microscopically in positively-stained sections at both low and high resolution. At low resolution, all six membranes exhibit a railroad track pattern, while at high resolution all six membranes exhibit a pattern of a double-tier of globular particles. The correspondence between the railroad track pattern and the double-tiered pattern is considered. The relationship of the double-tiered pattern to the bimodal properties of the constituent protein and phospholipid molecules is discussed. 相似文献
132.
Induction of a deoxycytidineless state in cultured mammalian cells by bromodeoxyuridine 总被引:21,自引:0,他引:21
Bromodeoxyuridine triphosphate is an allosteric inhibitor of ribonucleotide reductase, and bromodeoxyuridine can therefore kill cells by starving them for deoxycytidine nucleotides. The toxicity of bromodeoxyuridine for some cell lines is reduced many fold when deoxycytidine is also present. For example, wild type 3T6 cells can be grown serially in 1.5 × 10?4 Molar bromodeoxyuridine and 2 × 10?4 Molar deoxycytidine, remain healthy, and incorporate bromodeoxyuridine extensively into cellular DNA. Some of the numerous effects of this drug on the behavior of cells and viruses may be due to a deoxycytidineless state, rather than to the incorporation of the bromodeoxyuridine into DNA. 相似文献
133.
134.
Warren O. Kessler Ruben F. Gittes Sheldon R. Hurwitz Joseph P. Green 《The Western journal of medicine》1974,121(2):91-93
Gallium-67 (67Ga) citrate was administered intravenously (50 microcuries per kg of body weight) to patients in whom acute and chronic urinary tract infections were suspected. Scanning was done, using both the Anger-type scintillation camera and the rectilinear scanner, 24 to 78 hours after injection of the isotope.The preliminary results imply that 67Ga renal uptake is present in patients with pyelonephritis whether overt or silent, as well as in patients with uretero-sigmoidostomies. However, 67Ga renal uptake is not present in patients with radiographic evidence of chronic pyelonephritis without active infection and in patients without renal disease. 相似文献
135.
136.
137.
Conformational basis of energy transduction in mitochondria 总被引:1,自引:0,他引:1
138.
The isolation of cod muscle tropomyosin by heat treatment 总被引:1,自引:0,他引:1
139.
140.
Origin of the Thymidine Kinase Induced by Polyoma Virus in Productively Infected Cells 总被引:13,自引:4,他引:9
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Cells of the 3T3 mouse line efficiently supported the multiplication of polyoma virus, and the infectious process was accompanied by a marked increase in thymidine kinase (TK) activity. Two lines of 5-bromodeoxyuridine-resistant 3T3 cells have been isolated. As expected, these cells incorporated practically no exogenous thymidine into their deoxyribonucleic acid (DNA) and contained negligible TK activity. Like the parental 3T3 cells, TK(-) lines were susceptible to productive infection by polyoma virus, but infection did not lead to an increase in TK activity. Since kinase activity did appear after infection with another virus (vaccinia) known to contain the gene(s) for that enzyme, it is concluded that TK is not one of the gene products of polyoma virus. As induction of cellular DNA synthesis by polyoma virus occurs normally when the TK(-) cells are infected in the stationary phase, TK cannot play a role in the determination of this phenomenon. 相似文献