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61.
Enzymatic activities of uridine and thymidine phosphorylase in normal and cancerous uterine cervical tissues 总被引:1,自引:0,他引:1
Kobayashi Y Wada Y Ohara T Okuda Y Suzuki N Hasegawa K Kiguchi K Ishizuka B 《Human cell》2007,20(4):107-110
In this study, the preliminary analyses were conducted of enzymatic activities of uridine phosphorylase (UP) and thymidine phosphorylase (TP) in normal tissues and cancer tissues of the uterine cervix. The study was performed on 27 patients of cervical cancer, treated first in our hospital. Normal cervical tissues obtained from 15 patients undergoing hysterectomy for benign diseases were used as controls. The supernatant of the homogenated cervical tissues and the stroma (5-FU and ribose-1-P or deoxyribose-1-P) were analyzed by high performance liquid chromatography, and then the UP and TP activities calculated. TP activity was significantly greater than UP activity (P < 0.0001). Both UP and TP showed significantly greater activity in cancer tissues than in normal tissues (P < 0.0001). In the TP activity of the cancer tissues, there was no significant difference among the histological types, while the TP activity tended to be significantly higher in the cases with lymph node metastasis. These results showed that the TP-mediated route seemed important as the 5FU metabolic pathway in the uterine cervical tissues, and TP enzymatic activity might be associated with lymph node metastasis. 相似文献
62.
Nakamura T Hoaki T Hanada S Maruyama A Kamagata Y Fuse H 《FEMS microbiology letters》2007,277(2):157-164
Soluble methane monooxygenase (sMMO) and particulate methane monooxygenase (pMMO) gene clusters in the marine methanotroph Methylomicrobium sp. strain NI were completely sequenced and analysed. Degenerated primers were newly designed and used to amplify the gene fragments containing intergenic mmoX-Y and mmoD-C regions and a partial pmoC region. Phylogenetic analysis of amino acid sequences deduced from mmoX and pmoA, as well as of 16S rRNA gene sequences, indicated that this strain was most closely related to the halotolerant methanotroph Methylomicrobium buryatense. There were putative sigma(54)- and sigma(70)-dependent promoter sequences upstream of the sMMO and pMMO genes, respectively, and mmoG, which is known to be related to the expression and assembly of sMMO, existed downstream of the sMMO genes. These findings suggest that the major components and regulation of MMOs in this marine methanotroph are quite similar to those in freshwater methane oxidizers, despite the difference in their habitats. 相似文献
63.
Abscisic acid (ABA) is not a plant-specific compound but one found in organisms across kingdoms from bacteria to animals,
suggesting that it is a ubiquitous and versatile substance that can modulate physiological functions of various organisms.
Recent studies have shown that plants developed an elegant system for ABA sensing and early signal transduction mechanisms
to modulate responses to environmental stresses for survival in terrestrial conditions. ABA-induced increase in stress tolerance
has been reported not only in vascular plants but also in non-vascular bryophytes. Since bryophytes are the key group of organisms
in the context of plant evolution, clarification of their ABA-dependent processes is important for understanding evolutionary
adaptation of land plants. Molecular approaches using Physcomitrella patens have revealed that ABA plays a role in dehydration stress tolerance in mosses, which comprise a major group of bryophytes.
Furthermore, we recently reported that signaling machinery for ABA responses is also conserved in liverworts, representing
the most basal members of extant land plant lineage. Conservation of the mechanism for ABA sensing and responses in angiosperms
and basal land plants suggests that acquisition of this mechanism for stress tolerance in vegetative tissues was one of the
critical evolutionary events for adaptation to the land. This review describes the role of ABA in basal land plants as well
as non-land plant organisms and further elaborates on recent progress in molecular studies of model bryophytes by comparative
and functional genomic approaches. 相似文献
64.
65.
Ryota Imai Shoko Yokota Shoichiro Horita Yoichi Ueta Yuko Maejima 《Bioscience, biotechnology, and biochemistry》2019,83(2):202-211
Oxytocin is produced by neurons in the paraventricular nucleus (PVN) and the supraoptic nucleus in the hypothalamus. Various ion channels are considered to regulate the excitability of oxytocin neurons and its secretion. A-type currents of voltage-gated potassium channels (Kv channels), generated by Kv4.2/4.3 channels, are known to be involved in the regulation of neuron excitability. However, it is unclear whether the Kv4.2/4.3 channels participate in the regulation of excitability in PVN oxytocin neurons. Here, we investigated the contribution of the Kv4.2/4.3 channels to PVN oxytocin neuron excitability. By using transgenic rat brain slices with the oxytocin-monomeric red fluorescent protein 1 fusion transgene, we examined the excitability of oxytocin neurons by electrophysiological technique. In some oxytocin neurons, the application of Kv4.2/4.3 channel blocker increased firing frequency and membrane potential with extended action potential half-width. Our present study indicates the contribution of Kv4.2/4.3 channels to PVN oxytocin neuron excitability regulation.
Abbreviation: PVN, paraventricular nucleus; Oxt-mRFP1, Oxt-monometric red fluorescent protein 1; PaTx-1, Phrixotoxin-1; TEA, Tetraethylammonium Chloride; TTX, tetrodotoxin; aCSF, artificial cerebrospinal fluid;PBS, phosphate buffered saline 3v, third ventricle. 相似文献
66.
Katsumoto Y Hayashi Y Oshige I Omori S Kishii N Yasuda A Asami K 《Biophysical journal》2008,95(6):3043-3047
We have developed what we believe is an efficient method to determine the electric parameters (the specific membrane capacitance C(m) and the cytoplasm conductivity kappa(i)) of cells from their dielectric dispersion. First, a limited number of dispersion curves are numerically calculated for a three-dimensional cell model by changing C(m) and kappa(i), and their amplitudes Deltaepsilon and relaxation times tau are determined by assuming a Cole-Cole function. Second, regression formulas are obtained from the values of Deltaepsilon and tau and then used for the determination of C(m) and kappa(i) from the experimental Deltaepsilon and tau. This method was applied to the dielectric dispersion measured for rabbit erythrocytes (discocytes and echinocytes) and human erythrocytes (normocytes), and provided reasonable C(m) and kappa(i) of the erythrocytes and excellent agreement between the theoretical and experimental dispersion curves. 相似文献
67.
68.
Tsutsumi H Katagi M Miki A Shima N Kamata T Nishikawa M Nakajima K Tsuchihashi H 《Journal of chromatography. B, Analytical technologies in the biomedical and life sciences》2005,819(2):315-322
To prove the intake of recently controlled designer drugs, N-benzylpiperazine (BZP) and 1-(3-trifluoromethylphenyl)piperazine (TFMPP), a simple, sensitive and reliable method which allows us to simultaneously detect BZP, TFMPP and their major metabolite in human urine has been established by coupling gas chromatography-mass spectrometry (GC-MS) and high-performance liquid chromatography-electrospray ionization mass spectrometry (LC-ESI-MS). GC-MS accompanied by trifluoroacetyl (TFA) derivatization and LC-MS analyses were performed after the enzymatic hydrolysis and the solid phase extraction with OASIS HLB, and BZP, TFMPP and their major metabolites, 4'-hydroxy-BZP (p-OH-BZP), 3'-hydroxy-BZP (m-OH-BZP) and 4'-hydroxy-TFMPP (p-OH-TFMPP), have found to be satisfactorily separated on a semi-micro SCX column with acetonitrile-40 mM ammonium acetate buffer (pH 4) (75:25, v/v) as the eluent. The detection limits produced by GC-MS were estimated to be from 50 ng/ml to 1 microg/ml in the scan mode, and from 200 to 500 ng/ml in the selected ion monitoring (SIM) mode. Upon applying the LC-ESI-MS technique, the linear calibration curves were obtained by using the SIM mode for all analytes in the concentration range from 10 ng/ml to 10 microg/ml. The detection limits ranged from 5 to 40 ng/ml in the scan mode, and from 0.2 to 1 ng/ml in the SIM mode. These results indicate the high reliability and sensitivity of the present procedure, and this procedure will be applicable for proof of intake of BZP and TFMPP in forensic toxicology. 相似文献
69.
Yoichi Tamai Hisako Kojima Shintaro Saito† Kikue Uchida Rie Kitajima Hiroshi Komatsu Tsuneo Moriya‡ 《Journal of neurochemistry》1993,60(5):1854-1863
Abstract: The metamorphic changes in levels of glycolipids and myelin proteins and 2',3'-cyclic nucleotide 3'-phosphohydrolase (CNP) in the brains of bullfrog tadpoles, adult frogs, and axolotls were investigated, with particular emphasis on myelin maturation. The concentrations of cerebroside. sulfatide, and galactosyldiacylglycerol gradually increased from the onset of prometamorphosis throughout the active metamorphic period and then greatly increased after metamorphosis was completed. The ratio of glucocerebroside to galactocerebroside increased greatly in the prometamorphic period and then rapidly decreased to the frog level during the climax period. The fatty acid compositions of cerebroside and sulfatide showed a developmental change, with 24:1 being more predominant in the later metamorphic stage. The proportion of hydroxy fatty acids increased up to the onset of the prometamorphic stage and thereafter remained constant at ∼ 50% of the total. The CNP activity remained unchanged throughout metamorphosis at 60% that in frog myelin and increased in the adult frog. The composition of tadpole myelin proteins remained constant during metamorphosis, with large basic protein being the most abundant, and in the frog, proteolipid protein and large basic protein were present in comparable amounts. The two adult forms of axolotl, i.e., the neotenous and metamorphosed forms, exhibited almost identical myelin constituents, and CNP activity in the neotenous form amounted to one-fifth that in the bullfrog. These results indicate that active biosynthesis of myelin marker components occurs as metamorphosis proceeds, but more pronounced changes of myelin components occur after metamorphosis is completed. 相似文献
70.
Tsukasa Ohmori Yuji Kashiwakura Akira Ishiwata Seiji Madoiwa Jun Mimuro Yusuke Furukawa Yoichi Sakata 《The Journal of biological chemistry》2010,285(41):31763-31773
Vinculin is a highly conserved actin-binding protein that is localized in integrin-mediated focal adhesion complexes. Although critical roles have been proposed for integrins in hematopoietic stem cell (HSC) function, little is known about the involvement of intracellular focal adhesion proteins in HSC functions. This study showed that the ability of c-Kit+Sca1+Lin− HSCs to support reconstitution of hematopoiesis after competitive transplantation was severely impaired by lentiviral transduction with short hairpin RNA sequences for vinculin. The potential of these HSCs to differentiate into granulocytic and monocytic lineages, to migrate toward stromal cell-derived factor 1α, and to home to the bone marrow in vivo were not inhibited by the loss of vinculin. However, the capacities to form long term culture-initiating cells and cobblestone-like areas were abolished in vinculin-silenced c-Kit+Sca1+Lin− HSCs. In contrast, adhesion to the extracellular matrix was inhibited by silencing of talin-1, but not of vinculin. Whole body in vivo luminescence analyses to detect transduced HSCs confirmed the role of vinculin in long term HSC reconstitution. Our results suggest that vinculin is an indispensable factor determining HSC repopulation capacity, independent of integrin functions. 相似文献