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1.
Masayo Suzuki Hiroyuki Ishida Yukimasa Shiotsu Taisuke Nakata Shiro Akinaga Shigemitsu Takashima Toshiaki Utsumi Toshiaki Saeki Nobuhiro Harada 《The Journal of steroid biochemistry and molecular biology》2009,113(3-5):195-201
In order to evaluate the importance of estrogen production in tumor and surrounding tissues, we measured mRNA expression levels of 5 enzymes participating to estrogen synthesis in situ and 4 breast cancer-related proteins in 27 pairs of tumor and non-malignant tissues. Steroid sulfatase (STS) mRNA was more frequently detected in tumor tissues rather than in their non-malignant counterparts. Estrogen sulfotransferase (EST) was constantly expressed with high level not only in tumor tissues but also in their surrounding non-malignant counterparts. In contrast, mRNA expression levels of aromatase, and 17β-hydroxysteroid dehydrogenase type I and II were relatively low and detected only in small proportion of the patients. We also measured the mRNA expression levels of the same nine genes in tumor tissues of 197 breast cancer patients, and analyzed relationship between the mRNA expression level and the clinicopathological parameters. The mRNA expression levels of STS, aromatase and erbB2 in tumor tissues increased as breast cancer progressed. The tumoral mRNA expression levels of STS, estrogen receptor β, and erbB2 in patients with recurrence were higher than those in patients without recurrence. Upregulation of STS expression plays an important role in tumor progression of human breast cancer and is considered to be responsible for estrogen production in tumor and surrounding tissues. 相似文献
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Adenosine binding sites of rat pheochromocytoma PC 12 cell membranes: partial characterization and solubilization 总被引:1,自引:0,他引:1
Rat pheochromocytoma PC 12 cell membranes were shown to possess A2-like adenosine binding sites as assessed by using 5'-N-ethylcarboxamide[3H]adenosine [( 3H]NECA). Specific [3H]NECA binding to PC 12 cell membrane at 0 degrees C was saturable and showed a monophasic saturation profile. In contrast, [3H]NECA binding to PC 12 cell membrane at 30 degrees C exhibited a biphasic profile suggesting the presence of two specific binding site. The rank order of potency for inhibition of [3H]NECA binding at 0 degrees C was NECA greater than 2-chloroadenosine greater than 2',5'-dideoxyadenosine greater than isobutylmethylxanthine much greater than phenylisopropyladenosine. These adenosine binding sites were solubilized with sodium cholate and the solubilized portion retained the same ligand binding characteristics as those of the membrane-bound form. Gel filtration experiments indicated an apparent Stokes radius of 6.7 nm for these adenosine binding sites/detergent complexes. 相似文献
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Thermotropic phase behavior and stability of monosialoganglioside micelles in aqueous solution. 下载免费PDF全文
The thermotropic phase behavior of monosialoganglioside in a dilute aqueous dispersion at pH 6.8 was measured by using synchrotron radiation small-angle x-ray scattering and was analyzed by a shell-modeling method. Previous calorimetric studies on ganglioside systems have shown quite different thermotropic behaviors from other biological lipid systems, however, the details have still been ambiguous. Because of high statistical data and a shell-modeling analysis, we could elucidate the internal structural change of monosialoganglioside micelle induced by the elevation of temperature from 6 to 60 degrees C, that is, the shrinkage of the hydrophilic region and the slight expansion of the hydrophobic region occurring simultaneously, accompanying the elongation of the axial ratios of the ellipsoidal micelles. The model structures obtained explain the changes in the experimental scattering curves, the distance distribution functions, and the gyration radii. In addition we have also found an evident thermal hysteresis in the scattering curves and in the structural parameters. The present result suggests that the thickness of the hydrophilic region, namely, the conformation of oligosaccharide chains, is sensitive to a change of temperature. 相似文献
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Norepinephrine(NE) release in posterior nucleus(PH) of the hypothalamus was examined before and during acute shaker (oscillation) stress in sinoaortic denervated(SAD) and sham-operated(SO) rats. NE in PH extracellular fluid of freely moving rats was collected by microdialysis and measured by sensitive radioenzymatic assay. Three days after SAD or SO operation, mean arterial pressure(MAP) and heart rate(HR) were significantly higher in SAD rats than SO rats. Baseline levels of NE in PH dialysate were also significantly elevated in SAD rats. Although five minutes of shaker stress elicited pressor and tachycardic responses coupled with increased NE release in PH of both groups, the increases in MAP and dialysate NE were larger in SAD than SO rats. These findings indicate that noradrenergic neurons in the PH respond to stress-induced stimuli and receive tonic input from baroreflex pathways. 相似文献
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The formation of effective root nodules on a non-nodulating line (T201) of soybean (Glycine max (L.) Merr.,) was induced by a treatment with 2,4-dichlorophenoxyacetate (2,4-D). The induced nodules, inoculated with mixed Bradyrhizobium japonicum strains A1017 and IRj2101, had a normal internal structure, red in colour and the cells being filled with bacteroids. Externally, the induced nodules were of unusual shape, being paired or gourd-like in form and were attached to thickened roots. The nodules were capable of acetylene reduction (3.1–3.5 moles g-1 fresh weight nodules h-1), allowing the growth of plants with dark green leaves. 相似文献
7.
Properties of the Escherichia coli RuvA and RuvB proteins involved in DNA repair, recombination and mutagenesis 总被引:4,自引:0,他引:4
The ruvA and ruvB genes constitute an operon, which is regulated by the SOS system and involved in DNA repair, recombination and mutagenesis. RuvA protein binds to both single-stranded and double-stranded DNA. RuvB protein has weak ATPase activity. RuvA bound to DNA greatly enhances ATPase activity of RuvB. UV-irradiation to supercoiled DNA further enhances the stimulatory effect of RuvA on the RuvB ATPase activity. In the presence of ATP the RuvA-RuvB complex has an activity that renatures cruciform structures formed by heating and gradually cooling supercoiled DNA with an inverted repeat. These findings suggest that the RuvA-RuvB complex interacts with an irregular conformation in damaged DNA and induces conformational changes in DNA using energy provided by ATP hydrolysis, so that it facilitates DNA repair, recombination and error prone replication. 相似文献
8.
Structure and regulation of the Escherichia coli ruv operon involved in DNA repair and recombination. 总被引:23,自引:7,他引:16 下载免费PDF全文
H Shinagawa K Makino M Amemura S Kimura H Iwasaki A Nakata 《Journal of bacteriology》1988,170(9):4322-4329
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