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Teruo Okasora Mitsumasa Nagase Hiroshi Kawachi Katsuyuki Matsui Michiaki Orikasa Tetsuo Morioka Ichiroh Yamazaki Takashi Oite Fujio Shimizu 《Virchows Archiv. B, Cell pathology including molecular pathology》1991,60(1):41-46
Change in the localization of the antigen recognized by the proteinuria-inducing monoclonal antibody (MA) 5-1-6 in experimental nephrosis was studied by indirect and biotin-avidin immunofluorescence, and immunoperoxidase at light and electron microscopical levels. The proteinuric state was induced by the administration of the aminonucleoside of puromycin (PAN) or adriamycin. The antigen decreased in quantity and/or its distribution changed with an increase in the amount of protein excreted in both experimental models. Recovery from the alterations observed during the development and proteinuria appeared to occur when PAN-induced proteinuria subsided. This antigenic molecule may thus be essential for maintaining the normal permselectivity of glomerular capillary walls. 相似文献
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Summary The actin-activated ATPase activityPhysarum myosin was shown to be inhibited of M levels of Ca2+. To determine if Ca2+ regulates ATP-dependent movement ofPhysarum myosin on actin, latex beads coated withPhysarum myosin were introduced intoChara cells by intracellular perfusion. In perfusion solution containing EGTA, the beads moved along the parallel arrays ofChara actin filaments at a rate of 1.0–1.8 m/sec; however, in perfusion solution containing Ca2+, the rate reduced to 0.0–0.7 m/sec. The movement of beads coated with scallop myosin, whose actin-activated ATPase activity is activated by Ca2+, was observed only in the perfusion solution containing Ca2+, indicating that myosin is responsible for the inhibitory effect of Ca2+ onPhysarum myosin movement. The involvement of this myosin-linked regulation in the inhibitory effect of Ca2+ on the cytoplasmic streaming observed inChara internodal cell andPhysarum plasmodium was discussed.Abbreviations ATP
adenosine 5-triphosphate
- DTT
dithiothreitol
- EDTA
ethylenediaminetetraacetic acid
- EGTA
ethyleneglycolbis(-aminoethylether) N,N,N,N-tetraacetic acid
- PIPES
piperazine-N,N-bis(2-ethanesulfonic acid) 相似文献
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Studies on Mechano-Perception in Characean Cells: Development of a Monitoring Apparatus 总被引:3,自引:0,他引:3
An apparatus to monitor the electrical signal generated in Characells upon mechanical stimulation was developed. An internodalcell was stimulated by dropping a glass tubing with the intensityof the stimulus being controlled by changing either the weightof the glass tubing or the height from which it was dropped.Upon stimulation, a receptor potential was generated with theamplitude being dependent on the stimulus intensity. When thereceptor potential reached a threshold value, an action potentialwas generated. The receptor potential and action potential werecharacterized. The usefulness of this apparatus for analyzingreceptor potentials is discussed. (Received January 29, 1996; Accepted April 16, 1996) 相似文献
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Oarada M Tsuduki T Suzuki T Miyazawa T Nikawa T Hong-quan G Kurita N 《Biochimica et biophysica acta》2003,1622(3):151-160
The effect of dietary docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA) on host resistance to Paracoccidioides brasiliensis infection was investigated. Mice fed palm oil supplemented with DHA showed reduced antifungal activity in the spleen and liver, as compared with mice fed palm oil or soybean oil without supplementation with DHA. Mice fed DHA-supplemented soybean oil also showed reduced antifungal activity in the liver, but the extent of reduction was less profound. This reduction in antifungal activity was not observed with EPA-supplemented palm or EPA-supplemented soybean oil. These results suggest that two factors, DHA and palm oil in combination, are involved in reducing the host resistance. DHA-enriched palm oil was also responsible for an increase in DHA concentration and a marked decrease in arachidonic acid content in the spleen and liver. However, this group did not show elevated spleen and liver phospholipid hydroperoxide levels compared with the other groups, excluding the possibility that the reduction in antifungal activity observed with DHA-enriched palm oil is due to acceleration of in vivo lipid peroxidation. Greater infection-induced increases in spleen and serum interferon-gamma concentrations were observed in mice fed DHA-enriched palm oil compared with the other groups. 相似文献
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Fujita M Shiota S Kuroda T Hatano T Yoshida T Mizushima T Tsuchiya T 《Microbiology and immunology》2005,49(4):391-396
During the screening of compounds that potentiate the effect of antimicrobial agents against methicillin-resistant Staphylococcus aureus(MRSA), we found that an extract of thyme (Thymus vulgaris L) leaves greatly reduced the minimum inhibitory concentration (MIC) of tetracycline against MRSA. We isolated the effective compound and identified it as baicalein (5, 6, 7-trihydroxyflavone). One of the clinically isolated MRSA strains possessed tetK, a gene encoding active efflux pump for tetracycline. We examined the effect of baicalein on the efflux of tetracycline, using Escherichia coli KAM32/pTZ1252 carrying the tetK. The E. coli KAM32/pTZ1252 showed 8 to 16 times higher MIC than E. coli KAM32. We observed strong inhibition of transport of tetracycline by baicalein with membrane vesicles prepared from E. coli KAM32/pTZ1252. Baicalein also showed synergy with tetracycline in a MRSA strain that doesn't possess tetK, or with beta-lactams. Thus, mechanisms of the synergies seem to be versatile. 相似文献
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The growth factor for malo-lactic fermentation bacteria was partially purified from tomato juice, and some properties of the factor were examined. The factor was comparatively a low molecule, thermo-stable and insoluble in nonpolar organic solvents. The purified factor fraction showed positive reaction with Molisch-, tetrazolium- and Nessler-reagents, suggesting the existence of sugar and nitrogen as the chemical components. The treatment with cellobiase or cellulase-II resulted in the inactivation of the factor and simultaneously released the sugar constituent composed of glucose from the factor. These results indicated that the glucose residue might exist as the β-1,4-glucosidic linkage in the growth factor. 相似文献
10.
Mitsuyoshi Yoshikawa Toshifumi Kiyohara Teruo Iwasaki Izumi Yoshida 《Bioscience, biotechnology, and biochemistry》2013,77(9):1989-1990
We investigated the effects of compounds isolated from a methanolic extract of rose hips on melanin biosynthesis in B16 mouse melanoma cells and the possible mechanisms responsible for the inhibition of melanin biosynthesis. We found that, among the isolated compounds, quercetin was a particularly potent melanogenesis inhibitor. To reveal the mechanism for this inhibition, the effects on tyrosinase of B16 mouse melanoma were measured. Quercetin decreased the intracellular tyrosinase activity as well as the tyrosinase activity in a cell culture-free system. We also examined the cellular level of tyrosinase protein and found that quercetin dose-dependently inhibited tyrosinase protein expression. We consider from these results that the inhibition of melanogenesis by quercetin was due to the inhibition of both tyrosinase activity and of the protein expression. 相似文献