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排序方式: 共有1223条查询结果,搜索用时 15 毫秒
1.
K Kasai M Hiraiwa Y Suzuki N Banba T Emoto T Nakamura S I Shimoda 《Hormones et métabolisme》1986,18(9):625-629
Effect of prostacyclin (PGI2) on adenylate cyclase activity in human thyroid membranes was examined. PGI2 caused a dose- and time-dependent production of cyclic AMP (cAMP) with high potency. When GTP was added in concentrations up to 100 uM, the activation of adenylate cyclase by PGI2 was increased. In the assay medium containing 3 mM ATP, 10 uM GTP and nucleotide regenerating system, the replacement of Mg2+ by increasing concentrations of Mn2+ caused a progressive loss of PGI2 as well as TSH-stimulated adenylate cyclase activities, while high concentrations of Mg2+ (12 or 18 mM) slightly suppressed the activity stimulated by either PGI2 or TSH. Both agents had an additive effect on the stimulation of adenylate cyclase activity in the presence of either 6 mM Mg2+ or 6 mM Mn2+. Gamma-globulin fraction containing non-stimulatory TSH receptor antibody which was prepared from a patient with chronic thyroiditis, suppressed only TSH- but not PGI2-stimulation of the adenylate cyclase activity. These results suggest that PGI2 can stimulate the adenylate cyclase activity in human thyroid tissue, and that PGI2-stimulation may be mediated by the different system from TSH-dependent one. 相似文献
2.
E Kita N Katsui K Nishi M Emoto Y Yanagase S Kashiba 《Journal of general microbiology》1986,132(11):3095-3103
Mice orally infected with Campylobacter jejuni developed focal infiltrative necrotic lesions in the liver, as determined by both histology and liver function tests. The initial histopathological feature was a focal infiltrative lesion in the parenchyma and portal triads. Foci of infiltrative lesions became necrotic between days 30 and 60 post-inoculation (p.i.). During this period, portal infiltrates increased in severity. From month 4 p.i., focal areas of infiltrative necrosis in the liver parenchyma became extensive. Study of liver function demonstrated mild elevations of transaminases, alkaline phosphatase and lactic dehydrogenase, and also the presence of hypoalbuminaemia. Although histopathological changes of the liver became gradually more marked after day 30 p.i., liver functions of infected mice were most affected at 2 months p.i. The capacity of C. jejuni to induce hepatic lesions seemed to be related to that of organisms to persist in the gall bladder; there was no correlation between biliary carriage in infected mice and positive faecal culture. 相似文献
3.
T Nakamura K Kasai S Konuma T Emoto N Banba M Ishikawa S Shimoda 《Life sciences》1990,46(15):1045-1050
Immunoreactive-endothelin (ir-ET) concentrations were determined in peripheral maternal blood and in umbilical cord blood just after delivery. The concentrations in both the umbilical artery (2.83 +/- 1.36 pmol/l plasma, Mean +/- SD) and vein (3.37 +/- 1.53 pmol/l) were significantly higher than those found in maternal venous blood (1.43 +/- 1.02 pmol/l). On the other hand, ir-ET levels in maternal blood were not significantly different when compared with those found in non-pregnant women (1.50 +/- 0.83 pmol/l). No significant difference of ir-ET levels between the umbilical artery and vein was observed. A highly significant correlation (r = 0.60, p less than 0.01) of ir-ET levels between the umbilical artery and vein was observed. Also, a significant correlation (r = 0.48, p less than 0.01) between umbilical vein and maternal vein ir-ET levels with a weaker correlation (r = 0.36, p less than 0.05) between umbilical artery and maternal vein ir-ET levels was demonstrated. The present study indicates that ir-ET may be actively secreted in fetal circulation and the plasma levels in maternal and fetal circulation may have a possible relation. 相似文献
4.
K Kasai T Ohmori N Koizumi T Hosoya M Hiraiwa T Emoto Y Hattori S Shimoda 《Life sciences》1989,45(16):1451-1459
The activity of thyroid peroxidase (TPO) in porcine follicles cultured for 96 h in suspension with five hormones (5H) still attained over 50% of that in the freshly isolated follicles. On the other hand, the activity in those cultured with 5H + TSH (6H) was several times higher than that cultured with 5H after 96 h, although an initial decrease of TPO activity during the first 24 h of culture was observed in both conditions. The ability of follicles to metabolize iodide (uptake and organification) when cultured with 6H for 96 h was also several times higher than that of those cultured with 5H. The half-maximal dose of TSH for stimulation of TPO activity and iodide metabolism was 0.03-0.04 mU/ml and the effect was mediated by cAMP. These results indicate that in porcine thyroid follicles in primary suspension culture, TPO activity as well as the ability of iodide metabolism is induced by chronic TSH stimulation. In addition, epidermal growth factor (EGF, 10(-9)M) and phorbol 12-myristate 13-acetate (PMA, 10(-8) M) completely inhibited TSH stimulation on both activities and also basal (5H) activity of iodide metabolism. 相似文献
5.
6.
James H. Fitzpatrick Jr. Douglas Kintner †Mark Anderson †William M. Westler ‡Sherrie E. Emoto David D. Gilboe 《Journal of neurochemistry》1996,66(6):2612-2620
Abstract: The inorganic phosphate (Pi) NMR peak in brain has an irregular shape, which suggests that it represents more than a single homogeneous pool of Pi. To test the ability of the Marquardt-Levenberg (M-L) nonlinear curve fit algorithm software (Peak-Fit) to separate multiple peaks, locate peak centers, and estimate peak heights, we studied simulated Pi spectra with defined peak centers, areas, and signal-to-noise (S/N) ratios ranging from ∞ to 5.8. As the S/N ratio decreased below 15, the M-L algorithm located peak centers accurately when they were detected; however, small peaks tended to grow smaller and disappear, whereas the amplitudes of larger peaks increased. We developed an in vitro three-compartment model containing a mixture of Pi buffer, phosphocreatine, phosphate diester, and phosphate monoester (PME), portions of which were adjusted to three different pHs before addition of agar. Weighed samples of each buffered gel together with phospholipid extract and bone chips were placed in an NMR tube and covered with mineral oil. Following baseline correction, it was possible to separate the Pi peaks arising from the three compartments with different pH values if each peak made up 10–35% of total Pi area. In vivo, we identified the plasma compartment by intraarterial infusion of Pi. It was assumed that intracellular compartments contained high-energy phosphates and took up glucose. Based on these assumptions we subjected the brains to complete ischemia and observed that Pi compartments at pH 6.82, 6.92, 7.03, and 7.13 increased markedly in amplitude. If the brain cells took up and phosphorylated 2-deoxyglucose (2-DG), 2-DG-6-phosphate (2-DG-6-P) would appear in the PME portion of the spectrum ionized according to pHi. Four 2-DG-6-P peaks with calculated pH values of 6.86, 6.94, 7.04, and 7.15 did appear in the spectrum, thereby confirming that the four larger Pi peaks represented intracellular spaces. 相似文献
7.
Tomomi Hidaka Masao Goda Tomohisa Kuzuyama Naomi Takei Makoto Hidaka Haruo Seto 《Molecular & general genetics : MGG》1995,249(3):274-280
The biosynthetic pathway for production of the antibiotic fosfomycin by Streptomyces wedmorensis consists of four steps including the formation of a C-P bond and an epoxide. Fosfomycin production genes were cloned from genomic DNA using S. wedmorensis mutants blocked at different steps of the biosynthetic pathway. Four genes corresponding to each of the biosynthetic steps were found to be clustered in a DNA fragment of about 5 kb. Nucleotide sequencing of a large fragment revealed the presence of ten open reading frames, including the four biosynthetic genes and six genes with unknown functions. 相似文献
8.
K Kasai F Yamaguchi T Hosoya K Ichimura N Banba T Emoto M Hiraiwa A Hishinuma Y Hattori S Shimoda 《Life sciences》1992,51(14):1095-1103
Porcine thyroid follicles cultured in suspension for 96 h synthesized and secreted thyroid hormones in the presence of thyrotropin (TSH). The secretion of newly synthesized hormones was assessed by determining the contents of thyroxine (T4) and triiodothyronine (T3) in the media and by paperchromatographic analysis of 125I-labelled hormones in the media where the follicles were cultured in the presence and absence of inhibitors of hormone synthesis. The hormone synthesis and secretion was modified by exogenously added NaI (0.1-100 microM). The maximal response was obtained at 1 microM. Thyroid peroxidase (TPO) activity in the cultured follicles with TSH for 96 h was dose-dependently inhibited by NaI. One hundred microM of NaI completely inhibited TSH-induced TPO activity. Moreover, both epidermal growth factor (EGF: 10(-9) and 10(-8) M) and phorbol 12-myristate 13-acetate (PMA: 10(-8) and 10(-7) M) inhibited de novo hormone synthesis. An induction of TPO activity by TSH was also inhibited by either agent. These data provide direct evidences that thyroid hormone synthesis is regulated by NaI as well as TSH at least in part via regulation of TPO activity and also that both EGF and PMA are inhibitory on thyroid hormone formation. 相似文献
9.
Loc Van Nguyen Ryoji Takahashi Stephen Mwangi Githiri Tito O. Rodriguez Nobuko Tsutsumi Sayuri Kajihara Takasi Sayama Masao Ishimoto Kyuya Harada Keisuke Suematsu Tomomi Abiko Toshihiro Mochizuki 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》2017,130(4):743-755
Key message
Greatest potential, QTLs for hypoxia and waterlogging tolerance in soybean roots were detected using a new phenotypic evaluation method.Abstract
Waterlogging is a major environmental stress limiting soybean yield in wet parts of the world. Root development is an important indicator of hypoxia tolerance in soybean. However, little is known about the genetic control of root development under hypoxia. This study was conducted to identify quantitative trait loci (QTLs) responsible for root development under hypoxia. Recombinant inbred lines (RILs) developed from a cross between a hypoxia-sensitive cultivar, Tachinagaha, and a tolerant landrace, Iyodaizu, were used. Seedlings were subjected to hypoxia, and root development was evaluated with the value change in root traits between after and before treatments. We found 230 polymorphic markers spanning 2519.2 cM distributed on all 20 chromosomes (Chrs.). Using these, we found 11 QTLs for root length (RL), root length development (RLD), root surface area (RSA), root surface area development (RSAD), root diameter (RD), and change in average root diameter (CARD) on Chrs. 11, 12, 13 and 14, and 7 QTLs for hypoxia tolerance of these root traits. These included QTLs for RLD and RSAD between markers Satt052 and Satt302 on Chr. 12, which are important markers of hypoxia tolerance in soybean; those QTLs were stable between 2 years. To validate the QTLs, we developed a near-isogenic line with the QTL region derived from Iyodaizu. The line performed well under both hypoxia and waterlogging, suggesting that the region contains one or more genes with large effects on root development. These findings may be useful for fine mapping and positional cloning of gene responsible for root development under hypoxia.10.
Hitomi Y Watanabe S Kizaki T Sakurai T Takemasa T Haga S Ookawara T Suzuki K Ohno H 《Redox report : communications in free radical research》2008,13(5):213-216
Exercise dramatically increases oxygen consumption and causes oxidative stress. Superoxide dismutase (SOD) is important in the first-line defence mechanisms against oxidative stress. To investigate the effect of acute exercise on the expression of SOD, we examined the expression of mRNA for three SOD isozymes, in mice run on a treadmill to exhaustion. Six hours after exercise, the expression of extracellular SOD (EC-SOD) mRNA increased significantly in skeletal muscle and persisted for 24 h, whereas no change was observed for cytoplasmic and mitochondrial SOD mRNA. Moreover, acute exercise also induced EC-SOD mRNA in the aorta. These results suggest that a single bout of exercise is enough to augment the expression EC-SOD mRNA in skeletal muscle and the aorta, and may partly explain the beneficial effect of exercise. 相似文献