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641.
The suppression characteristics of Escherichia coli strain KO1 have been investigated. The growth patterns of nonsense mutants of RNA (GA and f2) and DNA (λ and T4) phages suggested that KO1 carried an amber, but not ochre or opal suppressors. The comparison of KO1 with previously identified amber suppressors indicated that KO1 differed from su1, su3 and su6 in its suppression pattern. KO1 and su2 shared some properties in common, for instance, their ability to suppress GA amber mutants with one exception (amN20) and the restriction of suppression capacity by the strr mutation. However, the suppression efficiency of KO1 (48%) was about three times that of su2 (18%). A possibility that KO1 contained a new amber suppressor is discussed. 相似文献
642.
Itaru Yamamoto Norio Muto Emi Nagata Tomoe Nakamura Yukio Suzuki 《Biochimica et Biophysica Acta (BBA)/General Subjects》1990,1035(1):44-50
Enzymatic transglucosylation from maltose to l-ascorbic acid (AA) with mammalian tissue homogenates was determined by a high-performance liquid chromatography method and compared with the reaction catalyzed by α-glucosidase from Aspergillus niger. The homogenates of small intestine and kidney had a high transglucosylase activity to form a new type of glucosylated AA, which was associated with α-glucosidase activity. The new compound was demonstrated to be an equimolar conjugate of AA and glucose by the spectral and quantitative analyses. In particular, it showed a high stability in a neutral solution and no reducing activity toward cytochrome c and a dye. These properties were very different from those of AA and l-ascorbic acid α-glucoside formed with α-glucosidase form A. niger, but they were consistent with those of l-ascorbic acid 2-O-phosphate and l-ascorbic acid 2-O-sulfate. Moreover, it exhibited a reducing power associated with AA after mild acid hydrolysis or treatment with rat intestinal α-glucosidase. These results indicate that it should be assigned the 2-O-α-glucoside structure. Consequently, i should be assigned the 2-O-α-glucoside structure. Consequently, it is concluded that mammalian α-glucosidase is able to form a very stable and nonreducing form of glucosylated AA through a specific transglucosylation reaction distinct from that of microbial α-glucosidase. 相似文献
643.
A Urabe F Takaku H Mizoguchi K Kubo K Ota N Shimizu K Tanaka N Mimura H Nihei S Koshikawa 《International journal of cell cloning》1988,6(3):179-191
Phase I and Phase II studies of recombinant human erythropoietin (rhEpo) were conducted in normal volunteers and in anemic patients with chronic renal failure on maintenance hemodialysis. Three hundred U/person of rhEpo was administered intravenously to healthy normal volunteers in the Phase I study, resulting in no subjective or objective changes. In the Phase II study, 66 patients with chronic renal failure on maintenance hemodialysis with less than 20% hematocrit values were treated with rhEpo in doses of 50 U/kg to 200 U/kg two or three times a week. Hematocrit values increased significantly during the 12 weeks, and the patients' conditions improved. Patients previously requiring blood transfusions became transfusion-independent during our study. There were no obvious side effects, thus indicating the safety and efficacy of rhEpo in the anemia of chronic renal failure. 相似文献
644.
S Miura Y Hara M Iitaka N Fukasawa K Hase M Urabe Y Sakatsume M Yanagisawa J Ishii S Kawazu 《Endocrinologia japonica》1991,38(6):647-653
To investigate the thyroid function in Bio-Breeding Worcester (BB/W) rats, we have examined the iodine metabolism, serum TSH and thyroid hormone levels in 8- and 16-week-old BB/W and normal Wistar (W) rats. At 8 weeks of age, serum TSH levels were significantly higher in BB/W rats than in W rats, although there was no difference in the serum levels of free T3 and free T4. Furthermore, the thyroidal radioactive iodine incorporation at 48 h was significantly lower in BB/W rats, suggesting that they might have some defects in iodine organification. At 16 weeks of age, serum TSH levels were also significantly higher in BB/W rats than in W rats. Furthermore, serum TSH levels in 16-week-old BB/W rats were significantly higher than in 8-week-old BB/W rats. The thyroid weight was significantly greater in BB/W rats, probably due to the increased serum TSH. The thyroidal radioactive iodine uptake at 48 h and the iodine content in the thyroid homogenates were significantly lower in BB/W rats. These results suggest that BB/W rats have some defect in iodine metabolism resulting in impaired thyroid hormone synthesis. 相似文献
645.
Toshihiko Saheki Hitomi Ito Akihiro Sekiguchi Atsuyoshi Nishina Toshihiro Sugiyama Takashi Izumi Itaru Kojima 《Cytotechnology》2008,57(2):137-143
To understand the molecular mechanism underlying vigorous proliferative activity of hepatic stem-like (HSL) cells, we performed
two-dimensional electrophoresis to identify the proteins statistically more abundant in rapidly growing undifferentiated HSL
cells than in sodium butyrate-treated differentiated HSL cells. Matrix-assisted laser desorption/ionization-time of flight
mass spectrometry and Mascot search identified 6 proteins including prohibitin, vimentin, ezrin, annexin A3, acidic ribosomal
phosphoprotein P0 and Grp75. Prohibitin and vimentin control the mitogen-activated protein (MAP) kinase pathway. Ezrin is
phosphorylated by various protein-tyrosine kinases and modulates interactions between cytoskeletal and membrane proteins.
Annexin A3 has a role in DNA synthesis. Acidic ribosomal phosphoprotein P0 and Grp75 play in protein synthesis. These results
suggest that the proteins related to the MAP kinase cascade had some role in continuous proliferation of HSL cells without
differentiation. 相似文献
646.
Closely related competitors comprising ofEscherichia coli strains having the same metabolic system and differing only with a few bases on the glutamine synthetase gene in the plasmid
pKGN were previously shown to coexist in a chemostat. The differences among these closely related competitors can be considered
large enough to allow coexistence as the level of enzyme activity is different. To bring the difference among competitors
to the slightest possible, the mutation was introduced on the noncoding region of the plasmid pKGN harbored in the wild-type
strain (strain W). The new strain, strain W’, carries the plasmid pKGN’ with a 4-base insertion at theHind III site in the polycloning site of pKGN. As the noncoding region is a nucleotide segment that is not translated into amino
acids, the relatedness between strains W and W’ is the closest possible from the genetic point of view. Interestingly, though
both strains are almost identical, they can coexist stably in a chemostat irrespective of the initial population size. These
experimental results suggest that in the natural ecosystem, no matter how akin competitors are, coexistence is not impossible. 相似文献
647.
Burst-promoting activity in anemia and polycythemia 总被引:1,自引:0,他引:1
H Fukamachi A Urabe T Saito F Takaku M Kubota 《International journal of cell cloning》1986,4(2):74-81
Burst-promoting activity (BPA) in the sera of patients with various types of anemia and polycythemia was compared with that of normal subjects by an in vitro method using mouse bone marrow cells. The control culture contained normal human AB serum instead of sample materials. Results were expressed as a percentage of burst numbers in control cultures. Serum erythropoietin (Epo) levels were determined by a radioimmunoassay. Serum BPA in patients with aplastic anemia (155.4 +/- 56.7%, mean +/- SD) was significantly higher than that in normal subjects (112.1 +/- 29.1%, Wilcoxon's rank sum test, P less than 0.05). However, serum BPA in patients with uremic anemia (122.2 +/- 26.5%), polycythemia vera (101.9 +/- 19.5%) and stress polycythemia (115.5 +/- 25.6%) was not significantly different from normal subjects. There was a correlation between serum BPA and Epo titers in patients with aplastic anemia and paroxysmal nocturnal hemoglobinuria (r = 0.81, t test, P less than 0.001). 相似文献
648.
Mamoru Urabe Takara Yamamoto Shuichi Yoshiji Hideo Honjo Okada Hiroji 《Steroids》1987,50(4-6):607-608
Homogenates of human adult liver are capable of aromatizing norethindrone (17-ethynyl-19-nortestosterone) to ethynylestradiol (17-ethynylestradiol). The evidence of ethynylestradiol formation was obtained using a Bio-Rad AG1-X2 column, thin-layer chromatography and co-crystallization. 相似文献
649.
S Yoshida Y Mizuguchi K Mizue H Sakamoto S Urabe 《Japanese journal of medical science & biology》1987,40(5-6):171-174
Prevalence of hepatitis B (HB) markers, antibodies to human T cell leukemia virus (HTLV-1) and antibodies to human immune deficiency virus 1 (HIV-1) in prostitutes working in Fukuoka city were studied. Sera were collected from 237 prostitutes during January-September, 1986. Among them, 9 (3.8%) were HB virus surface-antigen (HBs Ag) positive, of whom, 3 were HBe antigen positive and the remaining 6 were anti-HBe positive. The positive rate of anti-HBs was 34.2%. The incidence of anti-HTLV-1 in the prostitutes was 5.9%. These incidences are considered to be within the usual range in Kyushu district. No seropositive case for anti-HIV was found. 相似文献