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451.
452.
Yusuke Amino Yu-ki Tahara Kei Yamada Masakazu Nakazawa Uno Tagami Takaho Tajima 《Bioscience, biotechnology, and biochemistry》2017,81(9):1690-1698
Umami taste is imparted predominantly by monosodium glutamate (MSG) and 5′-ribonucleotides. Recently, several different classes of hydrophobic umami-imparting compounds, the structures of which are quite different from MSG, have been reported. To obtain a novel umami-imparting compound, N-cinnamoyl phenethylamine was chosen as the lead compound, and a rational structure-optimization study was conducted on the basis of the pharmacophore model of previously reported compounds. The extremely potent umami-imparting compound 2-[[[2-[(1E)-2-(1,3-benzodioxol-5-yl)ethenyl]-4-oxazolyle]methoxy]methyl]pyridine, which exhibits 27,000 times the umami taste of MSG, was found. Its terminal pyridine residue and linear structure are suggested to be responsible for its strong activity. The time taken to reach maximum taste intensity exhibited by it, as determined by the time-intensity method, is 22.0 s, whereas the maximum taste intensity of MSG occurs immediately. This distinct difference in the time-course taste profile may be due to the hydrophobicity and strong receptor affinity of the new compound. 相似文献
453.
Syed Bilal Ahmad Andrabi Michiru Tahara Ryuma Matsubara Tomoko Toyama Hiroka Aonuma Hitoshi Sakakibara Makoto Suematsu Kazuyuki Tanabe Tomoyoshi Nozaki Kisaburo Nagamune 《Parasitology international》2018,67(1):47-58
Cytokinins are plant hormones that are involved in regulation of cell proliferation, cell cycle progression, and cell and plastid development. Here, we show that the apicomplexan parasites Toxoplasma gondii and Plasmodium berghei, an opportunistic human pathogen and a rodent malaria agent, respectively, produce cytokinins via a biosynthetic pathway similar to that in plants. Cytokinins regulate the growth and cell cycle progression of T. gondii by mediating expression of the cyclin gene TgCYC4. A natural form of cytokinin, trans-zeatin (t-zeatin), upregulated expression of this cyclin, while a synthetic cytokinin, thidiazuron, downregulated its expression. Immunofluorescence microscopy and quantitative PCR analysis showed that t-zeatin increased the genome-copy number of apicoplast, which are non-photosynthetic plastid, in the parasite, while thidiazuron led to their disappearance. Thidiazuron inhibited growth of T. gondii and Plasmodium falciparum, a human malaria parasite, suggesting that thidiazuron has therapeutic potential as an inhibitor of apicomplexan parasites. 相似文献
454.
Tomomitsu Tahara Tomoyuki Shibata Masaaki Okubo Kazuya Sumi Takamitsu Ishizuka Masakatsu Nakamura Mitsuo Nagasaka Yoshihito Nakagawa Naoki Ohmiya Tomiyasu Arisawa Ichiro Hirata 《PloS one》2014,9(8)
Background
The neurochemical serotonin (5-HT) is an important signaling molecule in the gastrointestinal motor and sensory functions. A key regulator of 5-HT levels is the transmembrane serotonin transporter (5-HTT; SLC6A4) that governs the reuptake of 5-HT. Recent studies have indicated 5-HTT expression may be regulated by epigenetic mechanisms. We investigated DNA methylation status of SLC6A4 gene in the gastric mucosa from functional dyspepsia (FD) because of their potential role in dyspeptic symptoms.Methods
Endoscopic gastric biopsies were obtained from 78 subjects with no upper abdominal symptoms and 79 patients with FD. Bisulfite Pyrosequencing was carried out to determine the methylation status of promoter CpG islands (PCGIs), promoter non-CpG islands (PNCGIs) and gene body non-CpG islands (NPNCGIs) in the SLC6A4 gene. Gene expression was examined by real-time PCR.Results
In overall, methylation level of PCGIs was significantly lower in FD compared to control subjects (p = 0.04). On the other hand, methylation level of NPNCGIs was significantly higher in FD compared to control subjects (p = 0.03). Lower methylation level in PNCGIs was highlighted in the patients with PDS (p = 0.01), while higher methylation level in NPNCGIs was more prominent in the patients with EPS (p = 0.017). Methylation levels of PCGIs and PNCGIs were inversely correlated, while methylation levels of NPNCGIs was positively correlated with SLC6A4 mRNA levels in FD patients.Conclusions
Our data suggest that change in DNA methylation pattern of SLC6A4 in the gastric mucosa may have a role for developing FD. A role of epigenetics for developing FD needs to be further evaluated. 相似文献455.
We examined antioxidants exhibiting no effects on DNA cross-linking, which is the basis of psoralen and ultraviolet-A therapy for skin diseases, and suppressing oxidative DNA damage incidental to the therapy. Epigallocatechin gallate and esculetin effectively suppressed oxidative DNA damage with little effect on the formation of DNA cross-linking. These antioxidants might be useful in suppressing the adverse reaction induced by this therapy. 相似文献
456.
Tahara E Tahara H Kanno M Naka K Takeda Y Matsuzaki T Yamazaki R Ishihara H Yasui W Barrett JC Ide T Tahara E 《Cancer immunology, immunotherapy : CII》2005,54(8):729-740
Expression of an interferon inducible gene 6-16, G1P3, increases not only in type I interferon-treated cells but also in human senescent fibroblasts. However, the function of 6-16 protein is unknown. Here we report that 6-16 is 34 kDa glycosylated protein and localized at mitochondria. Interestingly, 6-16 is expressed at high levels in gastric cancer cell lines and tissues. One of exceptional gastric cancer cell line, TMK-1, which do not express detectable 6-16, is sensitive to apoptosis induced by cycloheximide (CHX), 5-fluorouracil (5-FU) and serum-deprivation. Ectopic expression of 6-16 gene restored the induction of apoptosis and inhibited caspase-3 activity in TMK-1 cells. Thus 6-16 protein has anti-apoptotic function through inhibiting caspas-3. This anti-apoptotic function is expressed through inhibition of the depolarization of mitochondrial membrane potential and release of cytochrome c. By two-hybrid screening, we found that 6-16 protein interacts with calcium and integrin binding protein, CIB/KIP/Calmyrin (CIB), which interacts with presenilin 2, a protein involved in Alzheimers disease. These protein interactions possibly play a pivotal role in the regulation of apoptosis, for which further detailed analyses are need. These results overall indicate that 6-16 protein may have function as a cell survival protein by inhibiting mitochondrial-mediated apoptosis. 相似文献
457.
458.
BD Biosciences is a leader in the use of flow cytometry for determining immune system status and for counting CD4 cells in patients with human immunodeficiency virus (HIV) infection. The company has gained this position through many years of basic research and product development in immunology and cell biology, dye chemistry, immunoassays, instrumentation, and software. Some of the highlights of these developments and their historical perspective are described in this review. 相似文献
459.
Katagiri Y Hashidoko Y Tahara S 《Zeitschrift für Naturforschung. C, Journal of biosciences》2002,57(9-10):811-816
Quantification of the flavonoids in yellow lupin (Lupinus luteus; Leguminosae) seedlings revealed that a flavone glucoside, 7-O-beta-(2-O-beta-rhamnosyl)glucosyl-4',5,7-trihydroxyflavone (apigenine 7-O-beta-neohesperidoside), is rich in the epicotyl and cotyledon. In hypocotyls and roots, 8-C-beta-glucosyl-4',5,7-trihydroxyisoflavone (genistein 8-C-beta-glucoside) was a predominant flavonoid constituent. The roles of the localized flavonoids are briefly discussed relating to defense against biotic and abiotic external stresses. 相似文献
460.
Katagiri Y Hashidoko Y Ibrahim RK Tahara S 《Zeitschrift für Naturforschung. C, Journal of biosciences》2001,56(11-12):1038-1046
Exogenous jasmonic acid (JA) and methyl jasmonate (MJ) induced accumulation of isoflavone constituents in cotyledons prepared from imbibed seeds of white lupin (Lupinus albus L.). Exogenous 0.2 mM MJ enhanced the levels of 7-O-(6"-O-malonyl)glucosylgenistein and 7-O-glucosylgenistein in the cotyledons of etiolated seedlings that had been incubated in the dark for 48 h. Regarding isoflavone induced by excision and slicing in the cotyledons as background level, the effect of light was 2- to 3-fold higher than that of 0.2 mM MJ. Cotyledons exposed to MJ along with a 24-h light period displayed a higher level of isoflavone accumulation than that of light alone. Total molar amounts of isoflavone accumulated in the cotyledons treated with MJ under continuous light were approximately the sum of those induced by MJ alone and light alone, respectively. The additive-like effect of MJ and light on isoflavone accumulation in lupin tissues suggested the presence of two different signaling systems independently responsible for those two stimuli. Excised cotyledons from etiolated yellow lupin (L. luteus L. cv. Topaz) seedlings also supported this hypothesis. The cotyledons could accumulate both an isoflavone and a flavone, and MJ selectively increased some of the isoflavone constituents, whereas light enhanced the levels of both. The selective accumulation mechanism of isoflavonoids in cotyledons, in which jasmonoids are involved, clearly differed from that activated by light. 相似文献