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141.
Hideyuki Matsushima Shun Shimohama Motohiko Chachin Takashi Taniguchi Jun Kimura 《Journal of neurochemistry》1996,67(1):317-323
Abstract: We examined protein kinase C (PKC) activity in Ca2+ -dependent PKC (Ca2+ -dependent PKC activities) and Ca2+ -independent PKC (Ca2+ -independent PKC activities) assay conditions in brains from Alzheimer's disease (AD) patients and age-matched controls. In cytosolic and membranous fractions, Ca2+ -dependent and Ca2+ -independent PKC activities were significantly lower in AD brain than in control brain. In particular, reduction of Ca2+ -independent PKC activity in the membranous fraction of AD brain was most enhanced when cardiolipin, the optimal stimulator of PKC-ε, was used in the assay; whereas Ca2+ -independent PKC activity stimulated by phosphatidylinositol, the optimal stimulator of PKC-δ, was not significantly reduced in AD. Further studies on the protein levels of Ca2+ -independent PKC-δ, PKC-ε, and PKC-ζ in AD brain revealed reduction of the PKC-ε level in both cytosolic and membranous fractions, although PKC-δ and PKC-ζ levels were not changed. These findings indicated that Ca2+ -dependent and Ca2+ -independent PKC are changed in AD, and that among Ca2+ -independent PKC isozymes, the alteration of PKC-ε is a specific event in AD brain, suggesting its crucial role in AD pathophysiology. 相似文献
142.
Oxygen consumption rates of tilapia in fresh water, sea water, and hypersaline sea water 总被引:5,自引:0,他引:5
Whole animal oxygen consumption rates and plasma constituents were determined in the tilapia O. mossambicus , acclimated for 1 month in fresh water, sea water, and 1·6 × sea water. Oxygen consumption rates for the three water salinities were: 177·2 ± 16·86, 78·6 ± 2·32, and 195·4 ± 15·39 mg O2 kg−1 h−1 (means ± 1 s.e.), respectively. Plasma prolactin (tPRL188 ) concentration was significantly lower in 1·6 × sea water compared to fresh and sea water. There were no significant differences among mean plasma cortisol concentration and lysozyme activity. Ventilation was significantly higher in fish in sea water compared to the fish in fresh and 1·6 × sea water. The lowest oxygen consumption rates were found in fish acclimated to sea water. That salinity is probably closest to the brackish waters from which they were captured in the wild, and this agreement likely reflects the selection for optimal morphological and physiological characteristics to live in that environment. 相似文献
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146.
Motohiko Hikuma Hiroshi Suzuki Takeo Yasuda Isao Karube Shuichi Suzuki 《Applied microbiology and biotechnology》1980,9(4):305-316
Summary A microbial electrode consisting of the immobilized microorganisms to be tested and an oxygen electrode was used to study the assimilation characteristics of microorganisms. When a sample solution containing a substrate was injected into the microbial sensor system, the current of the sensor markedly decreased with time if the microorganisms assimilated the substrate. On the other hand, no current decrease was observed if the microorganisms could not assimilate the substrate. Assimilation characteristics of various microorganisms such as molds, yeasts, bacteria, actinomycetes and activated sludges were tested with various substrates. The time required for a test was 30 min per substrate by the pulse method (sample injection period, 5 min). Good correlations were obtained between this electrochemical method and the conventional growth test. The fundamental differences between the two methods and the application of the electrochemical method are discussed. 相似文献
147.
Miura Yoshiharu; Yokoyama Hiroaki; Kimura Motohiko; Iwamoto Tsuneko; Miyamoto Kazuhisa 《Plant & cell physiology》1981,22(8):1375-1383
Hydrogen photoevolution by a thermophilic blue-green alga, Mastigocladuslaminosus, was investigated with respect to the effect of C2H2and/or CO on nitrogenase and H2 uptake activities. Nitrogenaseactivity, which supported H2 evolution of this alga, was increasedby one day of nitrogen starvation and thereafter remained ata high level. During the starvation, however, H2 uptake activityalso increased, resulting in a decreased and less sustainableH2 evolution. This uptake activity was sensitive to C2H2 butrather insensitive to CO. When assayed in the presence of C2H2and CO, H2 evolution in the decreased phase was restored tothe maximum value. In the mechanism of the restoration, C2H2and CO seemed to partially inhibit the H2 uptake catalyzed byhydrogenase and CO blocked all but the proton reducing activityof nitrogenase. In addition, further inhibition of H2 uptakeoccurred during incubation with C2H2, resulting in further stimulationof H2 evolution in the presence of both gases, or occurred immediatelyafter several hours of preincubation with C2H2. Such a delayedinhibition of H2 uptake by C2H2 did not involve the inhibitionof hydrogenase enzyme. (Received January 12, 1981; Accepted September 4, 1981) 相似文献
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S Ozawa T Iguchi K K Takemura H A Bern 《Proceedings of the Society for Experimental Biology and Medicine. Society for Experimental Biology and Medicine (New York, N.Y.)》1991,198(2):760-763
Neonatal treatment with diethylstilbestrol (DES) induces ovary-independent vaginal epithelial changes in mice. The response of vaginal epithelial cells from intact prepuberal BALB/cCrgl mice treated neonatally with 2 micrograms of DES for 5 days to growth-stimulatory and -inhibitory factors was studied using a serum-free collagen gel culture system that sustains the growth of normal vaginal epithelial cells. Cells from control and DES-exposed mice at 21 days of age showed about a 5-fold increase in number during 10 days in a serum-free medium supplemented with transferrin, bovine serum albumin fraction V, insulin, and epidermal growth factor. Epidermal growth factor and insulin stimulated dose-related proliferation of vaginal epithelial cells from both control and DES-exposed mice; however, cells from DES-exposed mice showed a reduced growth response to epidermal growth factor and an increased growth response to insulin, compared with control cells. Insulin-like growth factor I (1-100 ng/ml) tested in the absence of insulin failed to stimulate cell growth. Transforming growth factor-beta (0.05-5 ng/ml) consistently inhibited cell growth in a dose-dependent manner. 相似文献
150.