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961.
A.H. Koyama T. Maeda Sumi Toyama S. Ohnishi H. Uetake S. Toyama 《生物化学与生物物理学报:生物膜》1978,508(1):130-136
The nature of the interaction between Sendai virus and Sil mutant cells was examined by measuring a change in ESR spectrum of spin-labeled phosphatidylcholine molecules on the viral envelope. When spin-labeled virus was incubated with the Sil cells that had a reduced ability to respond to virus-induced cell fusion, interchange of the phospholipid molecules between viral envelope and cell surface membrane occurred to a smaller extent than that observed with parental cells. Moreover, the degree of the interchanging correlated with the degree of the fusion capacity of the mutant lines. The results show that the mutant cells carry such a lesion(s) on their surface membranes that the viral envelopes can hardly fuse into them. 相似文献
962.
963.
964.
O Maeda K Takenokuma Y Karoji A Kuroda O Sasaki T Karaki T Ishii 《Japanese journal of medical science & biology》1978,31(4):317-324
Natural infection with Japanese encephalitis virus in three sentinel pigs held in separate experimental huts was examined daily by virus recovery from blood samples of the pigs and from mosquitoes after incubation for about 7 days from their blood feeding and by HI antibody titration of the blood samples. After a period of low infection rates, below 6%, for about two weeks in engorged Culex tritaeniorhynchus summorosus, high mosquito infections of over 30% from each viremic pig occurred for two to three days. The pigs may be probably have been bitten by many infected but not infective mosquitoes in a period of about 10 days before infection. 相似文献
965.
K Sugahara K Ezaki T Kaneko T Morioka H Maeda 《Biochemical and biophysical research communications》1981,98(1):163-168
Structurally diverse anions (folate, 5-formyltetrahydrofolate, AMP, ADP, thiamine pyrophosphate, phosphate, sulfate, and chloride) that are competitive inhibitors of methotrexate influx in L1210 cells also enhance the efflux of methotrexate from these cells. The increase in efflux reaches a maximum of 2- to 4-fold depending upon the anion employed, and the anion concentrations required for half-maximal stimulation of efflux are similar to their Ki values for inhibition of methotrexate influx. A competitive inhibitor of methotrexate uptake (fluorescein-diaminopentane-methotrexate) that is not transported by this system, does not increase methotrexate efflux. These results suggest that the efflux of intracellular methotrexate is coupled to the concomitant uptake of an extracellular anion. 相似文献
966.
A designed mRNA consisting of 42 ribonucleotides having the cap structure was synthesized. The capped leader sequence of the brome mosaic virus (BMV) mRNA 4, m7G5'pppGUAUUAAUA (F-1), was synthesized by the phosphotriester method and followed by the capping reaction. A 32-mer consisting of an initiation codon (AUG), the coding region corresponding to a bacterial pheromone cAD1 and two stop codons, was constructed by the 18-mer (F-2) and 14-mer (F-3), which were synthesized by the phosphoramidite method. 2'-,3'-O-Methoxymethylene-guanosine 5'-phosphate was condensed with F-3 using P1-2',3'-O-methoxymethyleneguanosine-5'-yl P2-adenosine-5'-yl pyrophosphate (9) with T4 RNA ligase. The chemically synthesized RNA fragments were ligated successively with T4 RNa ligase to afford the whole RNA molecule. 相似文献
967.
K Maeda E Uchida H Tsukamura N Ohkura S Ohkura A Yokoyama 《Endocrinologia japonica》1990,37(3):405-411
The plasma LH concentration in ovariectomized lactating rats is low for 14 days postpartum, while the prolactin concentration is high during this period. We examined the effect of the inhibition of increased prolactin secretion with bromocriptine (CB-154) on the LH secretion in lactating rats ovariectomized on day 2 (day 0 = day of parturition). Blood samples were collected through an indwelling atrial cannula every day. LH levels were kept low until day 9 in lactating rats injected daily with CB-154 (0.6 mg/day, s.c.). The duration of the period during which LH secretion was suppressed was shorter in lactating rats treated with CB-154 than in saline-injected controls. The replacement with ovine prolactin by means of a mini-osmotic pump (0.3 mg/day, s.c.) in CB-154-treated lactating rats restored the duration of LH suppression. In rats deprived of their pups on day 2, the LH concentration rose immediately after removal of the pups and the LH level was not significantly different between rats treated with CB-154, ovine prolactin and saline, indicating that neither the CB-154 treatment nor the high level of prolactin alone has any effect on LH secretion in rats deprived of their pups. The present results clearly demonstrate that prolactin does not mediate the suppressing effect of the suckling stimulus on LH secretion in early lactation and support our theory that the suckling stimulus controls the LH and prolactin secretion independently at the hypothalamic level. 相似文献
968.
Seasonal changes in surface cover and long-term floral changes in aquatic plants of a shallow eutrophic pond, Ojaga-ike, as well as the phenology of each species, were studied. Out of ten floating-leaved and submerged plants, the following five species showed a change in surface cover during 1978: Potamogeton crispus and Elodea nuttallii occupied 53.5% of the total pond surface in May, Trapa natans and Nelumbo nucifera 79.1% in July, N. nucifera and Hydrilla verticillata 62.0% in September and N. nucifera 41.2% in November. In addition to dramatic seasonal changes in surface cover, long-term floral changes occurred in this pond from 1971 onwards. While Nymphoides indica, Myriophyllum spicatum and H. verticillata decreased in number and in distribution ranges between 1971 and 1978, two newly established plants, N. nucifera and E. nuttallii, have now become dominant. The alteration in dominance may be due to water level fluctuations and interspecific competition for light. Seasonal changes in water quality during the study period are also summarized. 相似文献
969.
We studied the proteolytic action in vitro of free and alpha 2-macroglobulin-bound porcine pancreatic elastase [EC 3.4.21.11] on the apolipoproteins of plasma: very low density lipoprotein (VLDL), low density lipoprotein (LDL), and high density lipoprotein (HDL). Polyacrylamide gel electrophoresis, isoelectric focusing and immunodiffusion tests of elastase-treated plasma lipoproteins revealed that apolipoprotein C-II and C-III polypeptides were more susceptible to elastase in free form than plasma apolipoproteins (A-I, A-II, B, and E). Elastase bound to alpha 2-macroglobulin did not show any such activities. 相似文献
970.
The DNA-binding protein of Pf1 filamentous bacteriophage: amino-acid sequence and structure of the gene 总被引:9,自引:0,他引:9
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Maeda K Kneale GG Tsugita A Short NJ Perham RN Hill DF Petersen GB 《The EMBO journal》1982,1(2):255-261
The amino-acid sequence of the single-stranded DNA-binding protein of bacteriophage Pf1 and the nucleotide sequence of the corresponding gene have been determined. The protein has 144 amino acids and a molecular weight of 15 400; the gene consists of 435 nucleotides. The amino-acid sequence was determined by Edman degradation, carboxypeptidase A, B, and P digestion of intact protein and of peptides derived by chymotrypsin, Staphylococcus aureus V8 protease, and trypsin digestion. The nucleotide sequence was determined by the dideoxy method after random cloning of fragments of Pf1 DNA into M13. No sequence homology could be established between the amino-acid sequence of the DNA-binding protein of Pseudomonas aeruginosa-specific bacteriophage Pf1 and bacteriophage fd of Escherichia coli. 相似文献