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排序方式: 共有502条查询结果,搜索用时 15 毫秒
1.
Makoto Tajima Nobuko Sekiguchi Masao Fujimaki 《Bioscience, biotechnology, and biochemistry》2013,77(2):319-320
High phosphate accumulating bacteria were isolated by autoradiography. One isoate, Arthrobacter globiformis PAB-6 accumulated phosphate intracellularly at 20% of dry cell mass in a simple synthetic medium. This amount was 3~7 times higher than type cultures examined. Almost no phosphate was released into the medium after cessation of growth. Fifty percent of total intracellular phosphate was fractionated as nucleic acids, while 20% each was recovered from cold PCA soluble fractions and polyphosphate fractions. The large content of nucleic acids in this bacterium appeared due to increased RNA content, specifically 4 S RNA fraction. 相似文献
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Katsuyuki Haranaka Nobuko Satomi Akiko Sakurai Ruriko Haranaka Naoko Okada Mosaburo Kobayashi 《Cancer immunology, immunotherapy : CII》1985,20(1):1-5
Summary The antitumor activities and capacity for tumor necrosis factor (TNF) production of traditional Chinese herbal preparations (Zhu-ling-tang, Xiao-chai-hu-tang), crude drugs (Polyporus, Hoelen, Bupleuri radix, Angelica radix, Cnidii rhizoma, Cinnamomum cortex), and Krestin (PSK) were investigated. These drugs were given to DDY mice in the drinking water before and after transplantation of Ehrlich tumors, and the development of the intradermally transplanted Ehrlich tumors and survival rate were observed. A good survival rate and sometimes a complete cure were found in the groups administered Bupleuri radix, Xiao-chai-hu-tang, Angelica radix, or Cinnamomum cortex, while the group given Hoelen showed poor results. To examine the capacity for TNF production these drugs were given to DDY mice PO as initial stimulating agents, to stimulate the reticuloendothelial system (RES) prior to lipopolysaccharide injection. The TNF activity was tested from the cytotoxicity against L cells. Significant differences in capacity for TNF production were observed among the drugs. Relatively high levels of TNF activity were noted in the groups given Angelica radix, Bupleuri radix, Cnidii rhizoma, or Cinnamomum cortex, very low activities in the groups given Xiao-chai-hu-tang, Zhu-ling-tang, or Krestin, and no TNF activities in the groups given Polyporus or Hoelen. The TNF capacity for production broadly paralleled the survival rate of the mice transplanted to Ehrlich tumors. Our findings suggest that one mechanism underlying the antitumor activities of these drugs is based on stimulation of the RES and is closely related of TNF production.This work was supported in part by a grant-in-aid from the Ministry of Education, Japan 相似文献
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Cell cycle dependence of cytotoxicity and clastogenicity induced by treatment of synchronized human diploid fibroblasts with sodium fluoride 总被引:11,自引:0,他引:11
To study the cell cycle dependence of cytotoxicity and clastogenicity of sodium fluoride (NaF), synchronized human diploid fibroblasts were treated with NaF during different phases of the cell cycle and analyzed. Exponentially growing cells were synchronized by the following two procedures. (1) The cells were synchronized at G0/G1 phase by a period of growth in medium containing 1% serum (low serum medium). (2) The cells were synchronized at the G1/S boundary by growth in low serum medium, followed by hydroxyurea treatment (Tsutsui et al., 1984a). Synchronized cells were treated with NaF for 3 h during the G1 phase or G2 phase, and for each of three 3-h periods during the S phase which lasted 9 h. Cytotoxicity, as determined by a decrease in colony-forming ability, was dependent upon the phase of the cell cycle during which NaF treatment was administered. The highest lethality was induced in when the cultures were treated with NaF during the second or third 3 h of S phase (middle or late S phase, respectively), or G2 phase. Little lethality was observed in cultures in G1 phase. Inducibility of chromosome aberrations of the cells following treatment with NaF was also dependent upon the phase of the cell cycle. A significant increase in the incidence of chromosome aberrations was observed only in cultures treated with NaF during early and / or middle S phases of cell cycle. These results suggest that cytotoxicity and clastogenicity of NaF to cultured human diploid fibroblasts are cell cycle dependent, and that the cells in early and middle S phases are more sensitive to the effects. 相似文献
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Effects of hydrostatic pressure on the ultrastructure and leakage of internal substances in the yeast Saccharomyces cerevisiae 总被引:2,自引:0,他引:2
Shoji Shimada Masayasu Andou Nobuko Naito Naoko Yamada Masako Osumi Rikimaru Hayashi 《Applied microbiology and biotechnology》1993,40(1):123-131
The structural damage to and leakage of internal substances from Saccharomyces cerevisiae 0–39 cells induced by hydrostatic pressure were investigated. By scanning electron microscopy, yeast cells treated at room temperature with pressuresbellw 400 MPa for 10 min showed a slight alteration in outer shape. Transmission electron microscopy, however, showed that the inner structure of the cell began to be affected, especially the nuclear membrane, when treated with hydrostatic pressure around 100 MPa at room temperature for 10 min; at more than 400–600 MPa, further alterations appeared in the mitochondria and cytoplasm. Furthermore, when high pressure treatment was carried out at — 20° C, the inner structure of the cells was severely damaged even at 200 MPa, and almost all of the nuclear membrane disappeared, although the fluorescent nucleus in the cytoplasm was visible by 4,6-diamidino-2-phenylindole (DAPI) staining. The structural damage of pressure-treated cells was accompanied by the leakage of internal substances. The efflux of UV-absorbing substances including amino acid pools, peptides, and metal ions increased with increase in pressure up to 600 MPa. In particular, amounts of individual metal ion release varied with the magnitude of hydrostatic pressures over 300 MPa, which suggests that the ions can be removed from the yeast cells separately by hydrostatic pressure treatment.
Correspondence to: S. Shimada 相似文献
9.
Nobuko Naito Evelyn Grace De Jesus Yasumitsu Nakai Tetsuya Hirano 《Cell and tissue research》1993,272(3):429-437
Tissue non-specific alkaline phosphatase is a membrane-bound glycoprotein enzyme which is characterized by its phosphohydrolytic, protein phosphatase, and phosphotransferase activities. This enzyme is distributed virtually in all mammalian tissues, particularly during embryonic development. Its expression is stagespecific and can be demonstrated in the developing embryo as early as the 2-cell stage. It has been suggested that tissue non-specific alkaline phosphatase might play a role in tissue formation. In the study reported here, a genetransfer approach was employed to investigate possible roles for this enzyme by inserting the cDNA for rat tissue non-specific alkaline phosphatase into CHO and LLC-PK1 cells. Permanently transfected cell-lines expressing varying levels of alkaline phosphatase were estblished. The data showed that functional enzyme was expressed in the transfected cells. Cell spreading and attachment were enhanced in transfected CHO cells expressing high levels of tissue non-specific alkaline phosphatase but not in the LLC-PK1 cells. Further, in CHO cells, proliferation was shown to be inversely proportional to the level of the tissue non-specific alkaline phosphatase expression. Homotypic cell association was demonstrated in both alkaline phosphatase-positive and alkaline phosphatase-negative cells in both CHO and LLC-PK1 celllines. Taken together, these findings suggest that in addition to a role in mineralization of bone, tissue nonspecific alkaline phosphatase might also play a role in other cell activities, including those related to differentiation, such as cell-cell or cell-substrate interaction and proliferation. 相似文献
10.
Populations of the two-spotted spider mite, Tetranychus urticae Koch collected from various localities and from various host plants in Japan showed wide variations in diapause attribute. Diapause percentages at 18°C/9L15D varied from nearly 100% in the north to 0% in the south-west. At intermediate latitudes the mites showed wide inter-population variations. Populations on herbaceous hosts in vinyl- or glass-houses gave significantly lower incidence of diapause than those on roses and deciduous fruit trees. Presence of winter hosts and better host quality under protected environments seemed to favour non-diapausing mites. The temperature threshold for diapause expression also varied widely among local populations. Northern populations consistently had higher and less variable thresholds than populations at intermediate latitudes with thresholds between 15 and 18°C. Inbred lines derived from a population in Kyoto exhibited a wide variation in diapause percentage at 18°C. These results show that diapause in T. urticae is a quantitative threshold trait and that populations in central Japan consist of a variety of genotypes with different diapause traits. This might provide a genetic source for adaptation to local and temporal variations in environmental conditions. 相似文献