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21.
Suzuki N Shiota T Watanabe F Haga N Murashi T Ohara T Matsuo K Oomori N Yari H Dohi K Inoue M Iguchi M Sentou J Wada T 《Bioorganic & medicinal chemistry letters》2011,21(6):1601-1606
A structure-activity relationship study of 4-anilinopyrimidines for dual EGFR/Her-2 inhibitor has resulted in the identification of 4-anilino-5-alkenyl or 5-alkynyl-6-methylpyrimidine derivatives that have exhibited effective inhibitory activity against both enzymes. The presence of 5-alkenyl or 5-alkynyl moiety bearing terminal hydrophilic group played important role for inhibition of these enzymes. Selected compounds in the series demonstrated some activity against Her-2 dependent cell line (BT474). 相似文献
22.
Keiichi Okada Takami Satomura Akihiko Kinoshita Takao Horikoshi Koh Yasue Masaki Fukuda Akiyoshi Yamada 《Mycoscience》2011,52(1):59-64
In this study, two plots in a secondary and another two in planted Pinus densiflora stands were exposed to different forest treatments, and the ectomycorrhizal (EM) biomass and its ergosterol content was measured
for a year. The unmanaged plot in the secondary stand had greater EM biomass than those in any other plots. Whereas understory
cutting had less effect on EM biomass, litter and humus removal decreased pine EM biomass and its ergosterol content, suggesting
that such forest treatment alters EM biomass and its structure. 相似文献
23.
Masamichi Takahashi 《American journal of botany》1995,82(7):847-854
Pollen development in Lilium longiflorum was reinvestigated with high resolution scanning electron microscopy, with special attention to three-dimensional conformation in the exine pattern formation. At the early tetrad stage, the invaginated plasma membrane takes the form of a reticulate pattern that corresponds to the mature exine tectum. Protectum is the first exine layer to be deposited on the reticulate-patterned plasma membrane. The initial protectum consists of aggregated fibrous threads and granules. Subsequently, probacules are formed under the protectum on the plasma membrane. At the free microspore stage the developing exine becomes further enlarged and the protectum develops into mature verrucate muri. The present three-dimensional investigation conflicts with the previous studies on exine development in Lilium. 相似文献
24.
Keizo Nishikawa Shigeto Seno Toshitada Yoshihara Ayako Narazaki Yuki Sugiura Reito Shimizu Junichi Kikuta Reiko Sakaguchi Norio Suzuki Norihiko Takeda Hiroaki Semba Masamichi Yamamoto Daisuke Okuzaki Daisuke Motooka Yasuhiro Kobayashi Makoto Suematsu Haruhiko Koseki Hideo Matsuda Masayuki Yamamoto Seiji Tobita Yasuo Mori Masaru Ishii 《EMBO reports》2021,22(12)
Oxygen plays an important role in diverse biological processes. However, since quantitation of the partial pressure of cellular oxygen in vivo is challenging, the extent of oxygen perturbation in situ and its cellular response remains underexplored. Using two‐photon phosphorescence lifetime imaging microscopy, we determine the physiological range of oxygen tension in osteoclasts of live mice. We find that oxygen tension ranges from 17.4 to 36.4 mmHg, under hypoxic and normoxic conditions, respectively. Physiological normoxia thus corresponds to 5% and hypoxia to 2% oxygen in osteoclasts. Hypoxia in this range severely limits osteoclastogenesis, independent of energy metabolism and hypoxia‐inducible factor activity. We observe that hypoxia decreases ten‐eleven translocation (TET) activity. Tet2/3 cooperatively induces Prdm1 expression via oxygen‐dependent DNA demethylation, which in turn activates NFATc1 required for osteoclastogenesis. Taken together, our results reveal that TET enzymes, acting as functional oxygen sensors, regulate osteoclastogenesis within the physiological range of oxygen tension, thus opening new avenues for research on in vivo response to oxygen perturbation. 相似文献
25.
26.
Noguchi M Ikarashi Y Yuzurihara M Kase Y Watanabe K Plotnikoff GA Takeda S Aburada M 《Life sciences》2005,76(18):2079-2090
The effects of Keishi-bukuryo-gan on calcitonin gene-related peptide (CGRP)-induced elevation of skin temperature were investigated in gonadotropin-releasing hormone (GnRH) analogue-treated female rats. Leupline (1.0 mg/kg) as the GnRH analogue was subcutaneously (s.c.) injected into female rats. After Keishi-bukuryo-gan (100-1,000 mg/kg, p.o.) or 17beta-estradiol (0.010 mg/kg, s.c.) was administered to GnRH analogue-treated rats for 14 days, CGRP-induced skin temperature elevation, concentration of plasma 17beta-estradiol and pituitary gonadotropin (luteinizing hormone; LH, and follicle stimulating hormone; FSH) were measured. In addition, effects of 17beta-estradiol and Keishi-bukuryo-gan on the proliferation of estrogen-dependent human breast cancer (MCF-7) cells were investigated under in vitro conditions. GnRH analogue significantly lowered the concentrations of plasma 17beta-estradiol and pituitary gonadotropins. Tissue weights of the ovaries and uterus were also decreased by the analogue. Under the condition of estrogen deficiency, intravenous (i.v.) injection of exogenous CGRP (10 microg/kg) elevated the skin temperature of the hind paws more significantly than it did in sham-treated control rats. Estrogen supplementation inhibited this elevation of skin temperature with restoration of both the lowered plasma estrogen level and the decreased uterine weight in GnRH analogue-treated rats. On the other hand, Keishi-bukuryo-gan inhibited the elevation of skin temperature in a dose-dependent manner without restoring the plasma estrogen level and uterine weight. In addition, in an in vitro study, MCF-7 cells proliferated in a dose-dependent manner by the addition of 17beta-estradiol (10(-13)-10(-8) M) to the medium. However, Keishi-bukuryo-gan (10(-6)-10(-4) mg/ml) did not activate the MCF-7 cell proliferation. These results suggest that Keishi-bukuryo-gan, which does not exhibit estrogen activity, may be useful for the treatment of hot flashes in women who are undergoing medical ovariectomy with a GnRH analogue. 相似文献
27.
28.
Fumiaki Abe Masamichi Muto Tomoko Yaeshima Keiji Iwatsuki Hiroaki Aihara Yuji Ohashi Tomohiko Fujisawa 《Anaerobe》2010,16(2):131-136
Although probiotic-containing nutrient formulas for infants and toddlers have become very popular, some adverse effects related to translocation of probiotic strains have been reported. We assessed the safety of probiotic bifidobacteria that have been used in clinical investigations and proven to have beneficial effects, by analyzing mucin degradation activity and translocation ability. Mucin degradation activities of three probiotic bifidobacteria strains; Bifidobacterium longum BB536, Bifidobacterium breve M-16V and Bifidobacterium infantis M-63, were evaluated by three in vitro tests comprising growth in liquid medium, SDS-PAGE analysis of degraded mucin residues, and degradation assay in Petri dish. All test strains and control type strains failed to grow in the liquid medium containing mucin as the only carbon source, although good growth was obtained from fecal sample. In the SDS-PAGE analyses of mucin residues and observation of mucinolytic zone in agar plate, the three test strains also showed no mucin degradation activity as the type strains, although fecal sample yielded positive results. In another study, a high dose of B. longum BB536 was administered orally to conventional mice to examine the translocation ability. No translocation into blood, liver, spleen, kidney and mesenteric lymph nodes was observed and no disturbance of epithelial cells and mucosal layer in the ileum, cecum and colon was detected, indicating that the test strain had no translocation ability and induced no damage to intestinal surface. These results resolve the concern about bacterial translocation when using bifidobacteria strains as probiotics, which have been tested in various clinical trials, supporting the continuous use of these probiotic strains without anxiety. 相似文献
29.
High density culture of hybridoma cells using a perfusion culture vessel with an external centrifuge 总被引:2,自引:1,他引:2
The influence of centrifugal force on the growth of cells was examined by exposing the cells of the mouse-human hybridoma X87 line to centrifugal force (100–500 G) for ten minutes twice a day and comparing the static culture with that of unexposed cells. In this experiment, both cell proliferation and specific antibody productivity were independent of the centrifugal effect, and gave the same results as in the case of no exposure to centrifugal force. High density cultivation of the mouse-human hybridoma X87 line was obtained by a perfusion system where the cells were separated from the culture medium by continuous centrifugation. In the serum-free culture, the maximum viable cell density exceeded 107 cells/ml, and monoclonal antibody was stably produced for 37 days. The results in this culture were equivalent to those obtained by intermittent centrifugal cell separation from the culture medium, and separation by gravitational settlement. 相似文献
30.
Masamichi Takahashi 《Journal of plant research》1989,102(2):219-234
Development of the echinate pollen grains inFarfugium (Compositae: Senecioneae) has been studied by a combination of transmission electron microscopy and field emission scanning
electron microscopy with a freeze fractured method. The inner surface of the callose wall surrounding each microspore does
not possess an echinate pattern before primexine deposition begins. The primexine formation coincides with the initiation
of spines. The freeze fractured primexine shows probacula which form transverse rods. The developing exine has an inner spongy
substructure. The endexine is formed by the accumulation of the electron dense lamellae with white lines after the dissolution
of the callose wall. In the present study, it is confirmed that the developmental process of pollen formation revealed in
the field emission scanning electron microscope is consistent with the results obtained using the transmission electron microscope. 相似文献