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991.
992.
Stimulatory effects of islet amyloid polypeptide (amylin) on exocrine pancreas and gastrin release in conscious rats. 总被引:2,自引:0,他引:2
A Funakoshi K Miyasaka K Kitani J Nakamura S Funakoshi H Fukuda N Fujii 《Regulatory peptides》1992,38(2):135-143
A rat islet amyloid polypeptide (amylin), 37-residue peptide amide was synthesized by the Fmoc-based solid phase method and the biological activity of synthetic rat amylin on exocrine pancreas was evaluated for the first time in conscious rat. Amylin (1, 10 nmol/kg/h) stimulated pancreatic exocrine secretion and plasma gastrin concentration. CR-1409, a CCK receptor antagonist, did not change amylin-stimulated pancreatic secretion. However, omeprazole (proton pump inhibitor) and atropine inhibited amylin-stimulated pancreatic secretion. This study suggests that amylin may play a role in biological action in the exocrine pancreas possibly mediated by gastric acid hypersecretion. 相似文献
993.
Kennichi Yanagi Hirotoshi Miyoshi Hideki Fukuda Norio Ohshima 《Applied microbiology and biotechnology》1992,37(3):316-320
Summary To enable high density culture of hepatocytes for use as a hybrid artificial liver support system or a bioreactor system, a packed-bed reactor using collagen-coated reticulated polyvinyl formal (PVF) resin was applied to a primary culture of hepatocytes. Cubic PVF resins (2×2×2 mm, mean pore size: 100, 250 or 500 m) were used as supporting substrates to immobilize hepatocytes. Two hundred and fifty cubes were packed in a cylindrical column, and 2.6–11.3×107 hepatocytes were seeded in the column by irrigating with 3 ml of the medium containing hepatocytes. Perfusion culture experiments using this packed-bed reactor, as well as monolayer cultures using conventional collagen-coated petri dishes as control experiments, were performed. Sufficient amounts of hepatocytes were found to be immobilized in the reticulated structure of the PVF resins. The highest density of immobilized hepatocytes attained with PVF resin was 1.2×107 cells/cm3 PVF, which showed levels of ammonium removal and urea-N secretion comparable to those in the monolayer culture. It is concluded that the packed-bed reactor system utilizing PVF resin is a promising process for developing a bioreactor or a bioartificial organ using hepatocytes.
Correspondence to: N. Ohshima 相似文献
994.
Summary Growth and death of anchorage-independent animal cells entrapped within porous biomass support particles (BSPs) in static or shake-flask cultures were evaluated by comparison of enzyme activity with non-immobilized cells grown under static culture using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) assay and release of lactate dehydrogenase into the culture medium. Mouse myeloma MPC-11 (ATCC CCL 167) cells inoculated within porous polyvinyl formal resin BSPs (3 × 3 × 3 or 2 × 2 × 2 mm; mean pore diameter, 60 ) grew exponentially at a specific growth rate comparable to that of non-immobilized cells in the initial period of incubation. Entrapped cells then reached the stationary phase with a cell density over 107 cells/cm3 BSP. The death rate of entrapped cells increased in response to the rise in viable cell density in the BSPs. Observation of viable cell distribution within the BSPs using MTT staining indicated that the cells concentrated within a thin outer shell of the BSPs with time. After the immobilized cells reached the stationary phase, penetration of cells into the outer shell ceased and heterogeneous distribution of cell density occurred in the viable cell layer in the shake-flask culture. 相似文献
995.
Covalently cross-linked multimers of cytokeratins were shown to be present in transplantable Morris hepatoma 7777 cells. These high molecular weight antigens were not detectable in normal rat liver cells. However, identical high molecular weight antigens were also demonstrated in rat liver cells when the cells were homogenized in solutions containing Ca2+. The cross-linking reaction was suggested to be mediated by the action of tissue transglutaminases. 相似文献
996.
Morquio disease: isolation, characterization and expression of full-length cDNA for human N-acetylgalactosamine-6-sulfate sulfatase. 总被引:7,自引:0,他引:7
S Tomatsu S Fukuda M Masue K Sukegawa T Fukao A Yamagishi T Hori H Iwata T Ogawa Y Nakashima 《Biochemical and biophysical research communications》1991,181(2):677-683
We cloned and sequenced a full-length cDNA of human placental N-acetylgalactosamine-6-sulfate sulfatase, the enzyme deficient in Morquio disease. The 2339-nucleotide sequence contained 1566 nucleotides which encoded a polypeptide of 522 amino acid residues. The deduced amino acid sequence was composed of a 26-amino acid N-terminal signal peptide and a mature polypeptide of 496 amino acid residues including two potential asparagine-linked glycosylation sites. Expression of the cDNA in transfected deficient fibroblasts resulted in higher production of this sulfatase activity than in untransfected deficient fibroblasts. The cDNA clone was hybridized to only a 2.3-kilobase species of RNA in human fibroblasts. The amino acid sequence of N-acetylgalactosamine-6-sulfate sulfatase showed a high degree of homology with those of other sulfatases such as human arylsulfatases A, B or C, glucosamine-6-sulfatase, iduronate-2-sulfatase and sea urchin arylsulfatase. 相似文献
997.
The major obstacle to clinical application of artificial blood vessel grafts with inside diameter of less than 4 mm is neogenic intimal hypertrophy at anastomotic sites. With the aim of preventing this artificial blood vessel graft anatomotic intimal hypertrophy, attempts have been made to improve surgical techniques and develop new materials for sutures and the grafts themselves. In the assessment of the preventive effects of various measures on anastomotic intimal hypertrophy, it is desirable to minimize variation in preoperative arteriosclerotic changes and uniform hemodynamics after vessel replacement surgery among the subjects. The present authors succeeded in creating an infrarenal abdominal aorta replacement model that meets these requirements using rabbits, and conducted experiments using this model to assess the effects of hyperlipidemia on anastomotic intimal hypertrophy. The anastomotic intimal hypertrophy lesion in the present rabbit infrarenal abdominal aorta replacement model is both morphologically and histologically similar to that found in human artificial blood vessel graft anastomotic sites. In addition, this model permits the easy obtain of animals showing the same hemodynamic status after vascular surgery. For these reasons, the present model is expected to serve well as an experimental model of artificial blood vessel graft anastomotic intimal hypertrophy. 相似文献
998.
Takumi Saito Van Tu Do Larisa Prozorova Takahiro Hirano Hiroshi Fukuda Satoshi Chiba 《Conservation Genetics》2018,19(4):947-958
Currently, many species are facing the risk of extinction, as it one of the most serious conservation issues. Many conservation programs have evolved to prevent species extinction; however, developing these strategies may prove to be difficult for the species itself, which includes different cryptic species. In this paper, we document the invasion of non-native cryptic species of ancylin limpets, Ferrissia californica, with a molecular phylogenetic analysis. Three species (F. nipponica, F. japonica, Gundlachia japonica) have been described as native, whereas the present analysis shows that most of them are actually non-native F. californica, having been introduced from North America and spreading throughout Japan. In addition, we found a few subpopulations of the cryptic native species of the ancylin limpets, though the native limpet species is very rare, and has limited distribution. The conservation status assigned to ancylin limpets on the Japanese red list is problematic, because F. japonica is listed as an endangered species. All individuals identified as F. japonica are of F. californica, so the current red list treats invasive non-native species as endangered. Reassessment of the conservation status of native species and an estimation of the impact of non-native species is required to better delineate these limpet species by genetic markers. 相似文献
999.
Chika Saito Wakana Ogawa Hisayasu Kobayashi Takashi Yamanaka Masaki Fukuda Akiyoshi Yamada 《Mycoscience》2018,59(1):89-97
The Japanese delicacy Tricholoma matsutake has been conducted in vitro ectomycorrhizal syntheses for more than 20 y. The development of its ectomycorrhizal structures varies among experimental systems. Here, we examined the effects of soil-fungus interactions on the early stage of in vitro T. matsutake ectomycorrhization. Axenic Pinus densiflora seedlings were transplanted into autoclaved natural inorganic soil, inoculated with the cultured mycelium of T. matsutake, and incubated for 90 d in vitro. Both soil type and fungal strain significantly affected host plant growth; host plant growth and mycorrhization levels significantly differed among soil type/fungal strain combinations. Therefore, the selection of T. matsutake strains for optimal mycorrhization must take into account such fungal and soil properties. 相似文献
1000.