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81.
Sugawara K Nakamura H Kanai M Iwata S Kawai Y Taki Y Yodoi J Takabayashi A 《Redox report : communications in free radical research》2002,7(3):165-169
Surgical stress is difficult to evaluate quantitatively. It has been reported that mitochondrial membrane potential (delta psi(m)) in the peripheral blood lymphocytes (PBLs) is decreased by surgical stress. Thioredoxin (TRX), a small protein with redox-active dithiol/disulfide in the active site, is induced by a variety of oxidative stresses and secreted from the cells. Accumulating evidence shows that plasma levels of TRX are elevated in oxidative stress-associated disorders. In the present study, we examined plasma levels of TRX in cases undergoing operations for gastrointestinal cancer. Plasma levels of TRX were significantly elevated on the first postoperative day compared with the pre-operative levels. The changes in the plasma TRX levels tended to show an inverse relationship with the changes in delta psi(m) in PBLs, which shows a significant decrease caused by surgical stress. Plasma TRX levels as well as delta psi(m) in PBLs are valuable markers to evaluate surgical stress. 相似文献
82.
83.
Stable isotope and radiocarbon compositions of methane emitted from tropical rice paddies and swamps in Southern Thailand 总被引:1,自引:0,他引:1
Fumiko Nakagawa Naohiro Yoshida Atsuko Sugimoto Eitaro Wada Takahito Yoshioka Shingo Ueda Pisoot Vijarnsorn 《Biogeochemistry》2002,61(1):1-19
Stable isotopes (13C, D) and radiocarbon weremeasured in methane bubbles emitted from rice paddies and swamps in southernThailand. Methane emitted from the Thai rice paddies was enriched in13C (mean 13C; –51.5 ±7.1 and–56.5 ± 4.6 for mineral soil and peat soil paddies,respectively)relative to the reported mean value of methane from temperate rice paddies(– 63 ± 5). Large seasonal variation was observed in13C(32) in the rice paddies, whereas variationinD was much more smaller (20), indicating that variation in13C is due mainly to changes in methane production pathways.Values of 13C were lower in swamps (–66.1 ±5.1)than in rice paddies. The calculated contribution of acetate fermentation from13C value was greater in rice paddies (mineral soils:62–81%, peat soils: 57–73%) than in swamps (27–42%). Din methane from Thai rice paddies (–324± 7 (n=46)) isrelativelyhigher than those from 14 stations in Japanese rice paddies ranging from–362 ± 5 (Mito: n=2) to –322 ± 8(Okinawa: n=3), due tohigher D in floodwaters. 14C content in methane produced fromThai rice paddies (127±1 pMC) show higher 14Cactivity compared with previous work in paddy fields and those from Thai swamps(110±2 pMC). 相似文献
84.
vas RNA has been identified in germ-line cells and its precursors in zebrafish, with the result that the germ-line lineage can be traced throughout embryogenesis. In the present study, we described vas localization and the migration of vas-positive cells in goldfish, using whole mount in situ hybridization. The signals of vas mRNA localization appeared at the marginal part of the first to third cleavage planes. The eight signals were detected during the period from the 8- cells to the 512-cell stage. At the late-blastula stage, additional numbers of vas-positive cells were observed, suggesting the proliferation of these cells. At the segmentation period, vas-positive cells showed a long extended distribution along the embryonic axis, but did not form any clusters. vas-positive cells were occasionally distributed at the head region, especially around the future otic vesicle. These signals were inherited to the primordial germ cells, suggesting that vas-positive cells were primordial germ cells (PGCs) in goldfish. 相似文献
85.
Yokomaku D Numakawa T Numakawa Y Suzuki S Matsumoto T Adachi N Nishio C Taguchi T Hatanaka H 《Molecular endocrinology (Baltimore, Md.)》2003,17(5):831-844
Changes in synaptic efficacy are considered necessary for learning and memory. Recently, it has been suggested that estrogen controls synaptic function in the central nervous system. However, it is unclear how estrogen regulates synaptic function in central nervous system neurons. We found that estrogen potentiated presynaptic function in cultured hippocampal neurons. Chronic treatment with estradiol (1 or 10 nm) for 24 h significantly increased a high potassium-induced glutamate release. The estrogen-potentiated glutamate release required the activation of both phosphatidylinositol 3-kinase and MAPK.The high potassium-evoked release with or without estradiol pretreatment was blocked by tetanus neurotoxin, which is an inhibitor of exocytosis. In addition, the reduction in intensity of FM1-43 fluorescence, which labeled presynaptic vesicles, was enhanced by estradiol, suggesting that estradiol potentiated the exocytotic mechanism. Furthermore, protein levels of synaptophysin, syntaxin, and synaptotagmin (synaptic proteins, respectively) were up-regulated by estradiol. We confirmed that the up-regulation of synaptophysin was blocked by the MAPK pathway inhibitor, U0126. These results suggested that estrogen enhanced presynaptic function through the up-regulated exocytotic system. In this study, we propose that estrogen reinforced excitatory synaptic transmission via potentiated-glutamate release from presynaptic sites. 相似文献
86.
We describe the use of direct injection of circular plasmid DNA and subsequent in vivo electroporation (EP) for efficient gene delivery to the ovarian cells, including follicular cells and oocytes of mice. When Trypan blue (TB) was injected into the central portion of an ovary by a glass micropipette, rapid dispersion of TB to each preantral and antral follicle was observed. Injections of lacZ-expressing plasmid DNA and subsequent in vivo EP resulted in transfection of follicles with efficiencies ranging from 8-60%, together with cells in the thecal portion of the ovary. Of the lacZ-positive follicles, some oocytes were also positive for lacZ activity. These findings suggest that a solution introduced inside the ovary is rapidly dispersed to each follicle. With this technique, we expect great progress in genetic engineering in murine ovary. 相似文献
87.
The chemical compositions of ground water and organic matter in sediments were investigated at a sandy shore of Tokyo Bay, Japan to determine the fate of ground water NO3
–. On the basis of Cl– distribution in ground water, the beach was classified into freshwater (FR)-, transition (TR)-, and seawater (SW)-zones from the land toward the shoreline. The NO3
– and N2O did not behave conservatively with respect to Cl– during subsurface mixing of freshwater and seawater, suggesting NO3
– consumption and N2O production in the TR-zone. Absence of beach vegetation indicated that NO3
– assimilation by higher plants was not as important as NO3
– sink. Low NH4
+ concentrations in ground water revealed little reduction of NO3
– to NH4
+. These facts implied that microbial denitrification and assimilation were the likely sinks for ground water NO3
–. The potential activity and number of denitrifiers in water-saturated sediment were highest in the low-chlorinity part of the TR-zone. The location of the highest potential denitrification activity (DN-zone) overlapped with that of the highest NO3
– concentration. The C/N ratio and carbon isotope ratio (13C) of organic matter in sediment (< 100 -m) varied from 12.0 to 22.5 and from –22.5 to –25.5, respectively. The 13C value was inversely related to the C/N ratio (r
2 = 0.968, n = 11), which was explained by the mixing of organic matters of terrestrial and marine origins. In the DN-zone, the fine sediments were rich in organic matters with high C/N ratios and low 13C values, implying that dissolved organic matters of terrestrial origin might have been immobilized under slightly saline conditions. A concurrent supply of NO3
– and organic matter to the TR-zone by ground water discharge probably generates favorable conditions for denitrifiers. Ground water NO3
– discharged to the beach is thus partially denitrified and fixed as microbial biomass before it enters the sea. Further studies are necessary to determine the relative contribution of these processes for NO3
– removal. 相似文献
88.
89.
Haraguchi K Takeda S Tanaka H Nitanda T Baba M Dutschman GE Cheng YC 《Bioorganic & medicinal chemistry letters》2003,13(21):3775-3777
Compounds having methyl, vinyl, and ethynyl groups at the 4'-position of stavudine (d4T: 2',3'-didehydro-3'-deoxythymidine) were synthesized. The compounds were assayed for their ability to inhibit the replication of HIV in cell culture. The 4'-ethynyl analogue (15) was found to be more potent and less toxic than the parent compound stavudine. 相似文献
90.
The process of egg formation in the body cavity of a phytoseiid mite, Phytoseiulus persimilis, was observed to examine fertilization of male eggs. After insemination, one of the ova at the periphery of the ovary began to expand, taking up yolk. Two pronuclei appeared in the expanded egg, located dorsally in the ovary, and yolk granules were formed gradually. After the egg became filled with yolk granules the two pronuclei fused. The egg moved via the narrow entrance at the ventral region into the oviduct, where the eggshell was formed. When the eggshell was complete, and while embryogenesis proceeded, the egg was deposited. In the meantime some ova began to expand sequentially and two joining pronuclei appeared in expanding eggs. The joining pronuclei in the first egg proved male diploidy. This is additional evidence of pseudo-arrhenotoky in this phytoseiid mite species, since the first eggs developed into males. 相似文献