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排序方式: 共有661条查询结果,搜索用时 771 毫秒
91.
Fukumoto K Nakahara K Katayama T Miyazatao M Kangawa K Murakami N 《Biochemical and biophysical research communications》2008,374(1):60-63
Gastrin and ghrelin are secreted from G cells and X/A-like cells in the stomach, respectively, and respective hormones stimulate gastric acid secretion by acting through histamine and the vagus nerve. In this study, we examined the relationship between gastrin, ghrelin and gastric acid secretion in rats. Intravenous (iv) administration of 3 and 10 nmol of gastrin induced transient increases of ghrelin levels within 10 min in a dose-dependent manner. Double immunostaining for ghrelin and gastrin receptor revealed that a proportion of ghrelin cells possess gastrin receptors. Although (iv) administration of gastrin or ghrelin induced significant gastric acid secretion, simultaneous treatment with both hormones resulted in a synergistic, rather than additive, increase of gastric acid secretion. This synergistic increase was not observed in vagotomized rats.These results suggest that gastrin may directly stimulate ghrelin release from the stomach, and that both hormones may increase gastric acid secretion synergistically. 相似文献
92.
We investigated patterns of acorn growth in Quercus variabilis Blume and Quercus serrata Thunb., seasonal trends in emergence of seed insects found in the acorns, oviposition periods of the insects and falling periods of insect-infested acorns. In Q. variabilis, two insect guilds were associated with acorn development: (i) the immature acorn feeding (IAF) guild [Curculionidae sp., Poecilips cardamomi (Schaufuss), and Characoma ruficirra (Hampson)]; and (ii) the mature acorn feeding (MAF) guild [Curculio robustus (Roelofs), Curculio sikkimensis (Heller), and Cydia glandicolana (Danilevsky)]. In Q. serrata, there were three guilds: (i) the pistillate flower feeding (PFF) guild (cynipid wasp); (ii) the IAF guild [sap absorption by Mechoris ursulus (Roelofs)]; and (iii) the MAF guild (M. ursulus, C. sikkimensis, Cydia danilevskyi (Kuznetzov), C. glandicolana and Autostichidae sp.). The succession of guilds during acorn development may be a consequence of the use by different species of the limited food resource. The lack of a PFF guild in Q. variabilis that was found in our field site would have a positive effect on IAF guilds in utilizing the acorns. 相似文献
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94.
Takashi Yokochi Izumi Nakashima Nobuo Kato Junpei Asai Soichi Iijima 《Microbiology and immunology》1980,24(10):933-944
The sequence of histological changes in the regional lymph node and other lymphoid organs of mice injected with the capsular polysaccharide of Klebsiella pneumoniae (CPS-K) or bacterial lipopolysaccharide (LPS) was followed. Injection of CPS-K, but not LPS, induced the following characteristic histological changes in the regional lymph node. In the early stage there was a marked decrease in the number of small lymphocytes, accompanied by the appearance of scattered fragmented nuclei and infiltration of polymorphonuclear neutrophilic leukocytes, and in the late stage there was marked proliferation of macrophage-like cells and pyroninophilic cells. Histological changes in the thymus and spleen and changes in cell populations in the bone marrow and peripheral blood after CPS-K injection were essentially the same as after LPS injection. Since CPS-K has a much stronger adjuvant action on antibody response than does LPS, it is suggested that the characteristic histological changes in the regional lymph node after injection of CPS-K are closely related to its extraordinarily strong adjuvant action. 相似文献
95.
Preservation of Purified Peanut Stripe and Turnip Mosaic Potyviruses by Freezing and Freeze-drying 总被引:1,自引:0,他引:1
During storage at - 20 °C of purified preparations of peanut stripe and turnip mosaic potyviruses, infectivity of intact particles and RNA extracted from preserved preparations decreased. This decrease can be attributed to several factors such as virus aggregation and alterations of the nucleic acids and coat proteins. However, the addition to the preparations of 0.5% peptone or 1% sucrose permitted a high level of infectivity to be retained for extended periods. Freeze-drying led to aggregation of the particles and in a marked decrease of infectivity. Virus aggregatioti and RNA degradation were suppressed by the addition of protectants such as 0.5% lysine. Results suggest that other potyviruses may be well preserved under similar conditions. 相似文献
96.
Mitsunori Kono Tsuneo Oda Michiko Tawada Takashi Imada Yoshihiro Banno Naohiro Taya Tetsuji Kawamoto Hidekazu Tokuhara Yoshihide Tomata Naoki Ishii Atsuko Ochida Yoshiyuki Fukase Tomoya Yukawa Shoji Fukumoto Hiroyuki Watanabe Keiko Uga Akira Shibata Hideyuki Nakagawa Satoshi Yamamoto 《Bioorganic & medicinal chemistry》2018,26(2):470-482
A series of tetrahydroisoquinoline derivatives were designed, synthesized, and evaluated for their potential as novel orally efficacious retinoic acid receptor-related orphan receptor-gamma t (RORγt) inverse agonists for the treatment of Th17-driven autoimmune diseases. We carried out cyclization of the phenylglycinamide core by structure-based drug design and successfully identified a tetrahydroisoquinoline carboxylic acid derivative 14 with good biochemical binding and cellular reporter activity. Interestingly, the combination of a carboxylic acid tether and a central fused bicyclic ring was crucial for optimizing PK properties, and the compound 14 showed significantly improved PK profile. Successive optimization of the carboxylate tether led to the discovery of compound 15 with increased inverse agonistic activity and an excellent PK profile. Oral treatment of mice with compound 15 robustly and dose-dependently inhibited IL-17A production in an IL23-induced gene expression assay. 相似文献
97.
98.
99.
Efficient transformation of pBR322 and its derived
plasmids, which have been widely used as cloning vectors in Escherichia
coli, was observed in Pseudomonas avenae (K1), the pathogen of
leaf blight disease in cereals. Moreover, there was a 10- to 50-fold
transformation efficiency (1.3–3.0 × 106/μg DNA) in the
proline-auxotrophic mutant (Pr47), whose virulence to rice seedlings
decreased. Similar enhancement of the frequency of transfer by mobilization
of RSF1010, a broad host range plasmid, was observed in the recipient Pr47
strain in mating with donor Pseudomonas syringae. The plasmids
harbored in these strains were maintained very stably after subcultures.
Thus, a highly efficient transformation system with pBR322-derived plasmids
used as a vector and Pseudomonas as a host bacterium was developed.
Received: 13 July 1996 / Accepted: 26 August 1996 相似文献
100.