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排序方式: 共有552条查询结果,搜索用时 15 毫秒
1.
K Nakashima T Tsukada H Hibasami S Maekawa 《Biochemical and biophysical research communications》1986,141(2):718-722
N-Chlorosulfonyl dicyclohexylamine (CSD) was synthesized as a potent inhibitor of spermidine synthase and analyzed for antiproliferative effects on leukemic cells. The compound specifically inhibited spermidine synthase in a competitive mode with the substrate putrescine (Ki, 1.8 X 10(-7) M). When human leukemia Molt4B cells were cultured in the presence of the inhibitor, the intracellular level of spermidine and the rate of cell proliferation were markedly depressed. In these polyamine depleted and growth retarded cells the synthesis of protein, but not of DNA or RNA, was found to be significantly diminished. 相似文献
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Novel lipase-catalyzed ring-opening copolymerization of lactide and trimethylene carbonate forming poly(ester carbonate)s. 总被引:3,自引:0,他引:3
S Matsumura K Tsukada K Toshima 《International journal of biological macromolecules》1999,25(1-3):161-167
Poly(lactide-co-trimethylene carbonate)s were prepared by the lipase-catalyzed ring-opening copolymerization of lactide and trimethylene carbonate having carbonate content from 0 to 100%. Their thermal properties and enzymatic degradability were measured. The L,L-, D,D- and D,L-lactides were copolymerized with trimethylene carbonate by porcine pancreatic lipase to produce random copolymers having molecular weights of up to 21000. The glass transition temperature (Tg of the copolymer was dependent on the carbonate content and the Tg values linearly decreased from 35 degrees C (polylactide) to -8 degrees C [poly(trimethylene carbonate)]. Among the lipases tested, the porcine pancreatic lipase and proteinase K showed biodegradability towards poly(ester-carbonate)s. 相似文献
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Tsuyoshi Tsukada Eriko Simamura Hiroki Shimada Takuma Arai Nobuaki Higashi Takuya Akai Hideaki Iizuka Toshihisa Hatta 《PloS one》2015,10(6)
Recent studies in rodents suggest that maternal immune activation (MIA) by viral infection is associated with schizophrenia and autism in offspring. Although maternal IL-6 is though t to be a possible mediator relating MIA induced these neuropsychiatric disorders, the mechanism remains to be elucidated. Previously, we reported that the maternal leukemia inhibitory factor (LIF)–placental ACTH–fetal LIF signaling relay pathway (maternal–fetal LIF signal relay) promotes neurogenesis of fetal cerebrum in rats. Here we report that the maternal–fetal LIF signal relay in mice is suppressed by injection of polyriboinosinic-polyribocytidylic acid into dams, which induces MIA at 12.5 days post-coitum. Maternal IL-6 levels and gene expression of placental suppressor of cytokine signaling 3 (Socs3) increased according to the severity of MIA and gene expression of placental Socs3 correlated with maternal IL-6 levels. Furthermore, we show that MIA causes reduction of LIF level in the fetal cerebrospinal fluid, resulting in the decreased neurogenesis in the cerebrum. These findings suggest that maternal IL-6 interferes the maternal–fetal LIF signal relay by inducing SOCS3 in the placenta and leads to decreased neurogenesis. 相似文献
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Tomoharu Tsukada Mizuki Takahashi Toshiyasu Takemoto Osamu Kanno Takahiro Yamane Sayako Kawamura Takahide Nishi 《Bioorganic & medicinal chemistry letters》2009,19(20):5909-5912
With the aim of discovering a novel class of fructose-1,6-bisphosphatase (FBPase) inhibitors, a series of compounds based on tricyclic scaffolds was synthesized. Extensive SAR studies led to the finding of 8l with an IC50 value of 0.013 μM against human FBPase. An X-ray crystallographic study revealed that 8l bound at AMP binding sites of human liver FBPase with hydrogen bonding interactions similar to AMP. 相似文献
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Yoshihiko Tsukada Atsushi Suetsugu Yosuke Osawa Hisataka Moriwaki 《Biochemical and biophysical research communications》2009,381(4):733-4088
Engelbreth-Holm-Swarm (EHS) gel has been reported to maintain the mature hepatocyte phenotypes in primary cultured hepatocytes. We investigated the effect of EHS gel on the differentiation of fetal liver cells, which contain stem/progenitor cells. The isolated fetal liver cells cultured on EHS gel formed a spherical shape and increased liver-specific gene expressions compared with cells cultured on collagen. The hepatic progenitor cells that were transplanted subcutaneously to BALB/c nude mice could survive and express hepatocyte marker alpha-fetoprotein when the cells were suspended with EHS gel. These findings demonstrate that EHS gel supports cytodifferentiation from immature progenitor cells to hepatocytes and maintain its differentiated phenotypes in vitro and in vivo. 相似文献
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Yoji Tsukada Hiroshi Taki Tsunetake Sugimori 《Bioscience, biotechnology, and biochemistry》2013,77(3):170-172
Riboflavin producing mutant of Zygosaccharomyces soja* was obtained by a treatment with cycloheximide. This mutant actively utilized various sugars and excreted riboflavin to the culture medium in a concentration of 30 to 40 μg per ml. Aerobic condition was prefered to sustain the growth of mutant and glucose catabolism was altered from alcohol fermentation in case of mother strain to respiration in mutant. This paper presents data obtained from morphological and physiological investigations. 相似文献
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