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61.
62.
Ozaki TJ Sato N Kitajo K Someya Y Anami K Mizuhara H Ogawa S Yamaguchi Y 《Cognitive neurodynamics》2012,6(2):185-198
An ambiguous figure such as the Necker cube causes spontaneous perceptual switching (SPS). The mechanism of SPS in multistable
perception has not yet been determined. Although early psychological studies suggested that SPS may be caused by fatigue or
satiation of orientation, the neural mechanism of SPS is still unknown. Functional magnetic resonance imaging (fMRI) has shown
that the dorsal attention network (DAN), which mainly controls voluntary attention, is involved in bistable perception of
the Necker cube. To determine whether neural dynamics along the DAN cause SPS, we performed simultaneous electroencephalography
(EEG) and fMRI during an SPS task with the Necker cube, with every SPS reported by pressing a button. This EEG–fMRI integrated
analysis showed that (a) 3–4 Hz spectral EEG power modulation at fronto-central, parietal, and centro-parietal electrode sites
sequentially appeared from 750 to 350 ms prior to the button press; and (b) activations correlating with the EEG modulation
traveled along the DAN from the frontal to the parietal regions. These findings suggest that slow oscillation initiates SPS
through global dynamics along the attentional system such as the DAN. 相似文献
63.
Properties of two different Na+/H+ antiport systems in alkaliphilic Bacillus sp. strain C-125. 下载免费PDF全文
Na+/H+ antiport was studied in alkaliphilic Bacillus sp. strain C-125, its alkali-sensitive mutant 38154, and a transformant (pALK2) with recovered alkaliphily. The transformed was able to maintain an intracellular pH (pHin) that was lower than that of external milieu and contained an electrogenic Na+/H+ antiporter driven only by delta psi (membrane potential, interior negative). The activity of this delta psi-dependent Na+/H+ antiporter was highly dependent on pHin, increasing with increasing pHin, and was found only in cells grown at alkaline pH. On the other hand, the alkali-sensitive mutant, which had lost the ability to grow above pH 9.5, lacked the delta psi-dependent Na+/H+ antiporter and showed defective regulation of pHin at the alkaline pH range. However, this mutant, like the parent strain, still required sodium ions for growth and for an amino acid transport system. Moreover, another Na+/H+ antiporter, driven by the imposed delta pH (pHin > extracellular pHout), was active in this mutant strain, showing that the previously reported delta pH-dependent antiport activity is probably separate from delta psi-dependent antiporter activity. The delta pH-dependent Na+/H+ antiporter was found in cells grown at either pH 7 or pH 9. This latter antiporter was reconstituted into liposomes by using a dilution method. When a transmembrane pH gradient was applied, downhill sodium efflux was accelerated, showing that the antiporter can be reconstituted into liposomes and still retain its activity. 相似文献
64.
Yoshiaki Suzuki Hisao Yamamura Susumu Ohya Yuji Imaizumi 《Biochemical and biophysical research communications》2013,430(3):1169-1174
Caveolin family is supposed to be essential molecules for the formation of not only caveola structure on cell membrane but also functional molecular complexes in them with direct and/or indirect interaction with other membrane and/or submembrane associated proteins. The direct coupling of caveolin-1 (cav1) with large conductance Ca2+-activated K+ channel, KCa1.1 has been established in several types of cells and in expression system as well. The possible interaction of caveolin-3 (cav3), which shows expression in some differential tissues from cav1, with KCa1.1 remains to be determined. In the present study, the density of KCa1.1 current expressed in HEK293 cells was significantly reduced by the co-expression of cav3, as well as cav1. The co-localization and direct interaction of GFP- or CFP-labeled cav3 (GFP/CFP-cav3) with YFP- or mCherry-labeled KCa1.1 (KCa1.1-YFP/mCherry) were clearly demonstrated by single molecular image analyses using total internal reflection fluorescence (TIRF) microscopy and fluorescence resonance energy transfer (FRET) analyses with acceptor photobleaching method. The deletion of suggested cav1-binding motif in C terminus region of KCa1.1 (KCa1.1ΔCB-YFP) resulted in the marked decrease in cell surface expression, co-localization and FRET efficiency with CFP-cav3 and CFP-cav1. The FLAG-KCa1.1 co-immunoprecipitation with GFP-cav3 or GFP-cav1 also supported their direct molecular interaction. These results strongly suggest that cav3 possesses direct interaction with KCa1.1, presumably at the same domain for cav1 binding. This interaction regulates KCa1.1 expression to cell surface and the formation of functional molecular complex in caveolae in living cells. 相似文献
65.
Tomohiro Yamaguchi Youichi Suzuki Ryuichi Katakura Takusaburo Ebina Junkichi Yokoyama Yoshiaki Fujimiya 《Cancer immunology, immunotherapy : CII》1998,47(2):97-103
γδT cells play a regulatory role in both primary and metastatic tumor growth in humans. The mechanisms responsible for the
activation and proliferation of circulating γδT cells should be fully understood prior to their adoptive transfer to cancer
patients. We have examined in vitro functional effects of interleukin-15 (IL-15) on highly purified γδT cells isolated from
glioblastoma patients. γδT cells constitutively express the heterotrimeric IL-2 receptor (IL-2R) αβγ, but the levels of IL-2Rβ
or γ expression were not increased by incubation with saturating amounts of IL-15. IL-15 was shown to induce a maximal γδT
cell proliferation, although at much higher concentrations (at least 2000 U/ml) than IL-2 (100 U/ml). Submaximal concentrations
of IL-15 plus low concentrations of IL-2 produced an additive proliferative response. In contrast to the IL-2-induced response,
this activity was completely or partially abrogated by anti-IL-2Rβ, or anti-IL-2Rγ antibodies, but not by anti-IL-2Rα antibodies.
Incubation of γδT cells in the presence of IL-15 resulted not only in the appearance of NK and LAK activity, but also in specific
autologous tumor cell killing activity, an additive effect being seen with IL-15 and IL-2. This IL-15-induced tumor-specific
activity could be significantly blocked by anti-IL-2Rγ and anti-IL-2R-β mAb, but not by anti-IL-2Rα mAb. Thus, in contrast
to IL-2, IL-15 activates tumor-specific γδT cells through the components of IL-2Rβ and IL-2Rγ, but not IL-2Rα. These enhanced
in vitro tumor-specific and proliferative responses of γδT cells seen with IL-15 suggest a rational adjuvant imunotherapeutic
use of γδT cells in cancer patients.
Received: 23 January 1998 / Accepted: 20 May 1998 相似文献
66.
Masaki Honda Tatsuya Kudo Takahiro Kuwa Takuma Higashiura Tetsuya Fukaya Yoshinori Inoue 《Bioscience, biotechnology, and biochemistry》2017,81(2):365-371
Lycopene has a large number of geometric isomers caused by E/Z isomerization at arbitrary sites within the 11 conjugated double bonds, offering varying characteristics related to features such as antioxidant capacity and bioavailability. However, the geometric structures of only a few lycopene Z-isomers have been thoroughly identified from natural sources. In this study, seven multi-Z-isomers of lycopene, (9Z,13′Z)-, (5Z,13Z,9′Z)-, (9Z,9′Z)-, (5Z,13′Z)-, (5Z,9′Z)-, (5Z,9Z,5′Z)-, and (5Z,9Z)-lycopene, were obtained from tomato samples by thermal isomerization, and then isolated by elaborate chromatography, and fully assigned using proton nuclear magnetic resonance. Moreover, the theoretically preferred pathway from (all-E)-lycopene to di-Z-isomers was examined with a computational approach using a Gaussian program. Fine-tuning of the HPLC separation conditions led to the discovery of novel multi-Z-isomers, and whose formation was supported by advanced theoretical calculations. 相似文献
67.
Masatsugu Ueda Eisaku Toji Osamu Nunobiki Shinji Izuma Yoshiaki Okamoto Kiyo Torii Sadamu Noda 《Human cell》2008,21(4):95-104
The multifactorial process of carcinogenesis involves mutations in oncogenes, or tumor suppressor genes, as well as the influence of environmental etiological factors. Common DNA polymorphisms in low penetrance genes have emerged as genetic factors that seem to modulate an individual’s susceptibility to malignancy. Genetic studies, which lead to a true association, are expected to increase understanding of the pathogenesis of each malignancy and to be a powerful tool for prevention and prognosis in the future. Here, we review the findings of genetic association studies of gene polymorphisms in gynecologic cancer with special reference to glutathione-S-transferase, FAS/CD95 and p53 genes including our recent research results. 相似文献
68.
Susumu Goto Yoshiaki Tsuda Yukihiro Koike Chunlan Lian Yuji Ide 《Ecological Research》2009,24(6):1267-1277
To evaluate the effects of landscape and demographic history on genetic variation in Picea glehnii at a regional scale we have investigated the genetic diversity and genetic differentiation of P. glehnii populations in the Furano region, central Hokkaido, Japan, using seven simple sequence repeat (SSR) markers. We found significant
correlations between elevation and genetic diversity parameters. The value of A
[46] increased and the value of F
IS decreased with increasing elevation, while F
IS values were not significantly different from 0 in any of the populations. Significant recent bottlenecks were detected for
isolated populations at low-elevation sites and for relatively large populations at moderate- and high-elevation sites. Evolutionary
events pre-dating the Holocene should be taken into consideration, as elevational gradients should be with respect to locally
adapted traits such as flowering phenology, However, the palynological data from the Holocene in this region suggest that
the distribution pattern of genetic diversity of P. glehnii detected here may have been influenced by past demographic history related to the elevation shifts in this species’ distribution
associated with climate change during this period. Population differentiation was low, with F
ST and G′ST values of 0.022 and 0.065, respectively. However, genetic boundaries were detected around one swamp population (C13). Therefore,
significant isolation by distance (IBD) was not detected when all populations were considered, but there was significant IBD
when the C13 population was excluded. Information on genetic diversity and genetic differentiation at the regional scale may
be useful for selecting seed sources for afforestation programs for P. glehnii. 相似文献
69.
Osamu Nunobiki Masatsugu Ueda Michiko Yamamoto Eisaku Toji Naomi Sato Shinji Izuma Yoshiaki Okamoto Kiyo Torii Sadamu Noda 《Human cell》2009,22(4):101-106
Genetic polymorphisms of p53 and its negative regulator murine double minute 2 homolog (MDM2) have been shown to be closely associated with tumorigenesis in a variety of human cancers. In the present study, single nucleotide polymorphism (SNP) at p53 codon 72 and MDM2 promoter 309 was examined for germline DNA samples from 102 endometrial cancer cases and 95 controls using polymerase chain reaction-based fragment analysis. There were no significant differences in the genotype and allele prevalence between control subjects and endometrial cancer patients for p53 codon 72. The GG genotype frequency of MDM2-SNP309 was statistically higher in endometrial cancer patients than that in normal healthy women when compared with the TG genotype ( P = 0.0088). However, no statistically significant differences were found between the TT and TG or GG genotype frequencies and allele prevalence. Interestingly, the combination of the homozygous Arg/Arg genotype of p53 codon 72 and homozygous GG genotype of MDM2 SNP309 polymorphisms was significantly associated with the risk of endometrial cancer (odds ratio = 3.28, 95% confidence interval = 1.13 to 9.53, P = 0.0212). The homozygous variants of wild p53 codon 72 and mutant MDM2 promoter 309 may cooperatively increase the risk of endometrial cancer in a Japanese population. 相似文献
70.