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991.
Two kinds of xyloglucan derivatives (xyloglucan selenious ester and sulfated xyloglucan) were prepared and evaluated on antioxidant activity and antitumor activity. Compared with xyloglucan, xyloglucan derivatives have new bioactivity against oxidative damage and tumor. Furthermore, xyloglucan selenious ester is more potent than sulfated xyloglucan at antioxidant activity and antitumor activity in vitro. The current data suggest for the first time that selenition of xyloglucan significantly increases its bioactivity and the chemical modification of polysaccharide may allow the preparation of derivatives with new properties and a variety of applications. 相似文献
992.
Toru Wada Yosuke Okamura Shinji Takeoka Ryo Sudo Yasuo Ikeda Kazuo Tanishita 《Journal of Biorheology》2009,23(1):35-40
Platelet glycoprotein GPIaIIa is an adhesive protein that recognizes collagen. We have investigated polymerized albumin particles
conjugated with recombinant GPIaIIa (rGPIaIIa-poly Alb) for their platelet-like function. To evaluate the feasibility of these
particles to achieve the hemostatic process, we measured the deformability (Young’s modulus and spring constant) and the adhesive
force of the particles using atomic force microscopy, which can measure the mechanical properties of individual cells. Our
results showed that the Young’s modulus of these particles was 2.3-fold larger than that of natural platelets and 12-fold
larger than that of human red blood cells. The Young’s modulus of the particles may have been determined by the properties
of the polymerized albumin particle, although the glycoprotein of the platelet surface also contributed to the higher modulus.
Our results also showed that the adhesive force of the rGPIaIIa-poly Alb with the collagen ligand was 52% of that of natural
platelets. These two mechanical properties (deformability and adhesive force) of cells or particles, such as rGPIaIIa-poly
Alb, are important specifications for the optimum design of platelet substitutes. 相似文献
993.
Masayuki Ikeda Moritoshi Hirono Takashi Sugiyama Takahiro Moriya Masami Ikeda-Sagara Naomi Eguchi Yoshihiro Urade Tohru Yoshioka 《PloS one》2009,4(11)
Background
The sleep sequence: i) non-REM sleep, ii) REM sleep, and iii) wakefulness, is stable and widely preserved in mammals, but the underlying mechanisms are unknown. It has been shown that this sequence is disrupted by sudden REM sleep onset during active wakefulness (i.e., narcolepsy) in orexin-deficient mutant animals. Phospholipase C (PLC) mediates the signaling of numerous metabotropic receptors, including orexin receptors. Among the several PLC subtypes, the β4 subtype is uniquely localized in the geniculate nucleus of thalamus which is hypothesized to have a critical role in the transition and maintenance of sleep stages. In fact, we have reported irregular theta wave frequency during REM sleep in PLC-β4-deficient mutant (PLC-β4−/−) mice. Daily behavioral phenotypes and metabotropic receptors involved have not been analyzed in detail in PLC-β4−/− mice, however.Methodology/Principal Findings
Therefore, we analyzed 24-h sleep electroencephalogram in PLC-β4−/− mice. PLC-β4−/− mice exhibited normal non-REM sleep both during the day and nighttime. PLC-β4−/− mice, however, exhibited increased REM sleep during the night, their active period. Also, their sleep was fragmented with unusual wake-to-REM sleep transitions, both during the day and nighttime. In addition, PLC-β4−/− mice reduced ultradian body temperature rhythms and elevated body temperatures during the daytime, but had normal homeothermal response to acute shifts in ambient temperatures (22°C–4°C). Within the most likely brain areas to produce these behavioral phenotypes, we found that, not orexin, but group-1 metabotropic glutamate receptor (mGluR)-mediated Ca2+ mobilization was significantly reduced in the dorsal lateral geniculate nucleus (LGNd) of PLC-β4−/− mice. Voltage clamp recordings revealed that group-1 mGluR-mediated currents in LGNd relay neurons (inward in wild-type mice) were outward in PLC-β4−/− mice.Conclusions/Significance
These lines of evidence indicate that impaired LGNd relay, possibly mediated via group-1 mGluR, may underlie irregular sleep sequences and ultradian body temperature rhythms in PLC-β4−/− mice. 相似文献994.
995.
Ayumi Ikeda Esteban C. Gabazza John Morser Ichiro Imoto Mikihito Kuroda Corina N. D'Alessandro-Gabazza Kenichiro Hara Daniel Boveda Ruiz Paloma Gil Bernabe Masaki Katsurahara Masaaki Toda Yoshinao Kobayashi Yutaka Yano Yasuhiro Sumida Koji Suzuki Osamu Taguchi Yoshiyuki Takei 《Helicobacter》2009,14(2):147-155
Thrombin-activatable fibrinolysis inhibitor (TAFI) plays a role in the regulation of coagulation and inflammation. In addition to inhibiting the fibrinolytic system, TAFI may also regulate the bradykinin and complement systems. We hypothesized that TAFI also plays a role in defense mechanisms of the gastric mucosa during Helicobacter pylori infection. This study comprised 65 patients with gastroduodenal disorders: 41 patients with H. pylori infection, 13 without, and 11 patients with cured H. pylori infection. The gastric intramucosal concentrations of TAFI were measured by enzyme immunoassay. The gastric levels of TAFI and plasminogen activator inhibitor-1 were significantly increased in patients with H. pylori compared to those without infection or cured H. pylori . The presence of TAFI was detected in gastric mucosal epithelial cells. The concentration of TAFI was correlated with the degree of gastric mucosal atrophy, inflammation, and disease activity. These results show that TAFI is present in the gastric mucosa and that it may play a role in the pathogenesis of H. pylori infection-associated gastroduodenal disorders. 相似文献
996.
Kentaro Morita Tomoyuki Yamamoto Naoki Fusada Mamoru Komatsu Haruo Ikeda Nobutaka Hirano Hideo Takahashi 《Molecular genetics and genomics : MGG》2009,282(6):607-616
We have previously shown that, in vivo, the integration system based on the gene encoding the TG1 integrase and the corresponding
attB
TG1
and attP
TG1
sites works well not only in Streptomyces strains, but also in Escherichia coli. Furthermore, the attachment sites for TG1 integrase are distinct from those of ϕC31 integrase. In this report, we expressed
TG1 integrase as a GST-TG1 integrase fusion protein and then used affinity separation and specific cleavage to release purified
integrase. Conditions for in vitro recombination were established using the purified TG1 integrase and its cognate attP
TG1
and attB
TG1
sites. TG1 integrase efficiently catalyzed a site-specific recombination between attB
TG1
and attP
TG1
sites irrespective of their substrate topology. The minimal sequences of attP
TG1
and attB
TG1
sites required for the substrates of TG1 integrase were demonstrated to be 43 and 39-bp, respectively. These results provide
the basic features of the TG1 integrase system to be used as biotechnological tools, as well as to unravel the mechanism of
the serine integrase. 相似文献
997.
Yu L Ikeda K Kato A Adachi I Godin G Compain P Martin O Asano N 《Bioorganic & medicinal chemistry》2006,14(23):7736-7744
The most common lysosomal storage disorder, Gaucher disease, is caused by inefficient folding and trafficking of certain variants of lysosomal beta-glucosidase (beta-Glu, also known as beta-glucocerebrosidase). Recently, Sawker et al. reported that the addition of subinhibitory concentrations (10 microM) of the pharmacological chaperone N-nonyl-1-deoxynojirimycin (NN-DNJ) (10) to Gaucher patient-derived cells leads to a 2-fold increase in activity of mutant (N370S) enzyme [Proc. Natl. Acad. Sci. U.S.A.2002, 99, 15428]. However, we found that the addition of NN-DNJ at 10 microM lowered the lysosomal alpha-glucosidase (alpha-Glu) activity by 50% throughout the assay period in spite of the excellent chaperoning activity in N370S fibroblasts. Hence, we prepared a series of DNJ derivatives with an alkyl chain at the C-1alpha position and evaluated their in vitro inhibitory activity and potential as pharmacological chaperones for Gaucher cell lines. Among them, alpha-1-C-octyl-DNJ (CO-DNJ) (15) showed 460-fold stronger in vitro inhibitory activity than DNJ toward beta-Glu, while NN-DNJ enhanced in vitro inhibitory activity by 360-fold. Treatment with CO-DNJ (20 microM) for 4 days maximally increased intracellular beta-Glu activity by 1.7-fold in Gaucher N370 cell line (GM0037) and by 2.0-fold in another N370 cell line (GM00852). The addition of 20 microM CO-DNJ to the N370S (GM00372) culture medium for 10 days led to 1.9-fold increase in the beta-Glu activity without affecting the intracellular alpha-Glu activity for 10 days. Only CO-DNJ showed a weak beta-Glu chaperoning activity in the L444P type 2 variant, with 1.2-fold increase at 5-20 microM, and furthermore maximally increased the alpha-Glu activity by 1.3-fold at 20 microM. These experimental results suggest that CO-DNJ is a significant pharmacological chaperone for N370S Gaucher variants, minimizing the potential for undesirable side effects such as alpha-Glu inhibition. 相似文献
998.
Kusunoki Y Yamaoka M Kubo Y Hayashi T Kasagi F Douple EB Nakachi K 《Radiation research》2010,174(6):870-876
In this paper we summarize the long-term effects of A-bomb radiation on the T-cell system and discuss the possible involvement of attenuated T-cell immunity in the disease development observed in A-bomb survivors. Our previous observations on such effects include impaired mitogen-dependent proliferation and IL-2 production, decreases in naive T-cell populations, and increased proportions of anergic and functionally weak memory CD4 T-cell subsets. In addition, we recently found a radiation dose-dependent increase in the percentages of CD25(+)/CD127(-) regulatory T cells in the CD4 T-cell population of the survivors. All these effects of radiation on T-cell immunity resemble effects of aging on the immune system, suggesting that ionizing radiation might direct the T-cell system toward a compromised phenotype and thereby might contribute to an enhanced immunosenescence. Furthermore, there are inverse, significant associations between plasma levels of inflammatory cytokines and the relative number of na?ve CD4 T cells, also suggesting that the elevated levels of inflammatory markers found in A-bomb survivors can be ascribed in part to T-cell immunosenescence. We suggest that radiation-induced T-cell immunosenescence may result in activation of inflammatory responses and may be partly involved in the development of aging-associated and inflammation-related diseases frequently observed in A-bomb survivors. 相似文献
999.
Zin’ichi Karube Yoichiro Sakai Tomohiro Takeyama Noboru Okuda Ayato Kohzu Chikage Yoshimizu Toshi Nagata Ichiro Tayasu 《Ecological Research》2010,25(4):847-855
Carbon and nitrogen stable isotope ratios (δ13C and δ15N) of macroinvertebrates inhabiting littoral zones of lakes can serve as useful indicators of material loading from the watershed. We collected snails (Semisulcospira spp.) and bivalves (Unio douglasiae biwae Kobelt) from 29 littoral sites in Lake Biwa near the mouths of river tributaries with various human population density (HPD) and land-use patterns. The δ13C and δ15N signatures were determined for three potential food sources: particulate organic matter in the pelagic zone (PPOM), riverine particulate organic matter from tributaries (RPOM) and epilithic organic matter in the littoral zone (EOM). The stable isotope mixing model revealed that snails relied mainly on EOM, and bivalves on PPOM and RPOM. Multiple regression analysis showed that intersite variation in δ15N for snails was best explained by HPD, while variation in δ15N of EOM and nitrate was explained to a lesser extent by HPD. Comparison with isotope signatures of their food sources and riverine nutrients revealed that snails assimilated anthropogenic nitrogen from wastewater in the watershed. Our results also showed that the δ13C value of bivalves was marginally related to the fraction of paddy fields in the watersheds. In conclusion, the isotope signatures of macroinvertebrates inhabiting the littoral zone can be useful indicators of anthropogenic impacts from the watershed. 相似文献
1000.
Pollen tubes of Cyrtanthus mackenii, a species with bicellular pollen, were cultured in vitro to investigate nuclear phase changes during generative cell division
and male germ unit (MGU) formation, using flow cytometric analysis. Results revealed that sperm cells were formed after 12 h
of culture. During sperm maturation, the nuclei of sperm cells were not associated with the vegetative nucleus (unassociated
sperm cells; Sua) and became longer than those of sperm cells associated with the vegetative nucleus (Svn). These findings
indicate that the pair of sperm cells in the C. mackenii MGU is dimorphic in terms of nuclear shape. Dimorphism coincides with anti-α-tubulin antibody immunofluorescence, which was
higher in the Sua than in Svn. Following treatment with oryzalin, triggering microtubule depolymerization, differences between
nuclear shapes in the two sperm nuclei disappeared, suggesting that microtubule accumulation between sperm cells in the MGU
correlates with differences in the nuclear shape. 相似文献