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排序方式: 共有668条查询结果,搜索用时 31 毫秒
21.
Takahiro Shiga Yoshifumi Kimira Hiroshi Mano Tetsunori Kawata Tadahiro Tadokoro Tsukasa Suzuki 《Bioscience, biotechnology, and biochemistry》2016,80(3):510-513
Vitamin B12 deficiency is a risk factor for bone disorders via mechanisms not fully understood. In this study, an increase in serum inorganic phosphorus (Pi) concentrations was associated with a vitamin B12 deficiency. Napi2a, a renal cotransporter for Pi reabsorption, accumulated on plasma membranes in a vitamin B12 deficiency suggests that vitamin B12 plays an important role in Pi homeostasis. 相似文献
22.
Hideyuki Yoshida Caleb A. Lareau Ricardo N. Ramirez Samuel A. Rose Barbara Maier Aleksandra Wroblewska Fiona Desland Aleksey Chudnovskiy Arthur Mortha Claudia Dominguez Julie Tellier Edy Kim Dan Dwyer Susan Shinton Tsukasa Nabekura YiLin Qi Bingfei Yu Michelle Robinette Christophe Benoist 《Cell》2019,176(4):897-912.e20
23.
Ghrelin, an endogenous ligand for the growth hormone secretagogue receptor (GHS-R), was isolated from the rat stomach and determined to be n-octanoylated 28-amino-acid peptide. In this study, we studied the distribution of ghrelin-producing cells (ghrelin cells) in the gastrointestinal tract of male and female rainbow trout (Oncorhynchus mykiss) by immunohistochemistry using N-terminal region-recognizing antibody and also by in situ hybridization using a trout ghrelin-specific cRNA probe. Ghrelin cells were found in the mucosal layer of the stomach but not in the myenteric plexus, and no ghrelin cells were observed in other regions of the gastrointestinal tract. Ghrelin cells could be classified into two types: closed- and opened-type cells. The density of ghrelin cells increased gradually in the direction from the cardiac to pyloric portions of the stomach in both sexes. The number of ghrelin cells per unit area seemed to be higher in females than in males. In conclusion, trout ghrelin cells exist in the stomach and are classified into two types of cells, closed- and opened-type cells. 相似文献
24.
We successfully isolated a novel aerobic chemolithotrophic sulfur-oxidizing bacterium, designated strain SO07, from wastewater biofilms growing under microaerophilic conditions. For isolation, the use of elemental sulfur (S(0)), which is the most abundant sulfur pool in the wastewater biofilms, as the electron donor was an effective measure to establish an enrichment culture of strain SO07 and further isolation. 16S rRNA gene sequence analysis revealed that newly isolated strain SO07 was affiliated with members of the genus Halothiobacillus, but it was only distantly related to previously isolated species (89% identity). Strain SO07 oxidized elemental sulfur, thiosulfate, and sulfide to sulfate under oxic conditions. Strain SO07 could not grow on nitrate. Organic carbons, including acetate, propionate, and formate, could not serve as carbon and energy sources. Unlike other aerobic sulfur-oxidizing bacteria, this bacterium was sensitive to NaCl; growth in medium containing more than 150 mM was negligible. In situ hybridization combined with confocal laser scanning microscopy revealed that a number of rod-shaped cells hybridized with a probe specific for strain SO07 were mainly present in the oxic biofilm strata (ca. 0 to 100 micro m) and that they often coexisted with sulfate-reducing bacteria in this zone. These results demonstrated that strain SO07 was one of the important sulfur-oxidizing populations involved in the sulfur cycle occurring in the wastewater biofilm and was primarily responsible for the oxidation of H(2)S and S(0) to SO(4)(2-) under oxic conditions. 相似文献
25.
Akira?Kikkawa Akira?KidoEmail author Tsukasa?Kumai Toru?Hoshida 《World journal of surgical oncology》2004,2(1):33
Background
Fibromatosis or desmoid tumor covers a broad spectrum of benign fibrous tissue proliferations. It is characterized by infiltrative growth and a tendency towards recurrence; however, unlike sarcoma, it never metastasizes. 相似文献26.
Sasamori K Sasaki T Takasawa S Tamada T Nara M Irokawa T Shimura S Shirato K Hattori T 《American journal of physiology. Lung cellular and molecular physiology》2004,287(1):L69-L78
Cyclic ADP-ribose (cADPR), a putative Ca(2+)-mobilizing second messenger, has been reported to operate in several mammalian cells. To investigate whether cADPR is involved in electrolyte secretion from airway glands, we used a patch-clamp technique, the measurement of microsomal Ca(2+) release, quantification of cellular cADPR, and RT-PCR for CD38 mRNA in human and feline tracheal glands. cADPR (>6 microM), infused into the cell via the patch pipette, caused ionic currents dependent on cellular Ca(2+). Infusions of lower concentrations (2-4 microM) of cADPR or inositol 1,4,5-trisphosphate (IP(3)) alone were without effect on the baseline current, but a combined application of cADPR and IP(3) mimicked the cellular response to low concentrations of acetylcholine (ACh). Microsomes derived from the isolated glands released Ca(2+) in response to both IP(3) and cADPR. cADPR released Ca(2+) from microsomes desensitized to IP(3) or those treated with heparin. The mRNA for CD38, an enzyme protein involved in cADPR metabolism, was detected in human tissues, including tracheal glands, and the cellular content of cADPR was increased with physiologically relevant concentrations of ACh. We conclude that cADPR, in concert with IP(3), operates in airway gland acinar cells to mobilize Ca(2+), resulting in Cl(-) secretion. 相似文献
27.
Takahashi T Matsumoto T Nakamura M Matsui H Kiyohara H Sasakawa C Yamada H 《Helicobacter》2004,9(4):302-312
BACKGROUND: Helicobacter pylori is found within the gastric surface mucous gel layer and in the epithelial surface. Gastric cancer cells have been used in experimental H. pylori infection in vitro, although cancer cells have some abnormalities in cellular properties. The aim of this study was to develop an in vitro H. pylori infection model using normal gastric surface cells that produce gastric mucin. MATERIALS AND METHODS: Normal murine gastric surface mucous cells (GSM06) were cultured by the liquid interface method using a serum-free medium and a collagen gel containing a fibroblast cell line (L929) and infected with H. pylori. Infection by H. pylori was assessed by enumerating the colony-forming units (CFU) of H. pylori adhered to GSM06 cells and by transmission electron microscopy. The production of mucin was determined by a lectin binding assay, sugar analysis, and MUC5AC gene expression. RESULTS: GSM06 cells cultured under these conditions produced mucin containing N-acetylgalactosamine and MUC5AC as the core protein. Significantly higher numbers of H. pylori adhered to GSM06 cells under mucin-producing conditions than under nonproducing conditions. Microscopic observation showed a filamentous structure resembling a type IV secretion system apparatus formed between the surface of GSM06 cells and H. pylori. CONCLUSIONS: This study demonstrates a novel in vitro H. pylori infection model using mucin-producing murine GSM06 cells for early stages of infection. 相似文献
28.
Syntheses and biological evaluation of novel quinuclidine derivatives as squalene synthase inhibitors 总被引:2,自引:0,他引:2
Ishihara T Kakuta H Moritani H Ugawa T Sakamoto S Tsukamoto S Yanagisawa I 《Bioorganic & medicinal chemistry》2003,11(11):2403-2414
Squalene synthase (E.C. 2.5.1.21) catalyses the reductive dimerization of two molecules of farnesyl diphosphate to form squalene and is involved in the first committed step in cholesterol biosynthesis. Inhibition of this enzyme is therefore an attractive target for hypocholesterolemic strategies. A series of quinuclidine derivatives incorporating a tricyclic system was synthesized and evaluated for their ability to inhibit squalene synthase in vitro. A 9H-fluorene moiety was found to be optimal as the tricyclic system for potent inhibitory activity. Improved activity can be achieved with a conformationally constrained three-atom linkage connecting the tricyclic system with the quinuclidine nucleus. Among these compounds, (Z)-3-[2-(9H-fluoren-2-yloxy)ethylidene]-quinuclidine hydrochloride 31 was found to be a potent inhibitor of squalene synthase derived from hamster liver and human hepatoma cells with IC(50) values of 76 and 48 nM, respectively. Oral dosing of compound 31 demonstrated effective reduction of plasma non-HDL cholesterol levels in hamsters. 相似文献
29.
Maehashi E Sato C Ohta K Harada Y Matsuda T Hirohashi N Lennarz WJ Kitajima K 《The Journal of biological chemistry》2003,278(43):42050-42057
The 350-kDa sperm-binding protein (SBP), a species-specific sperm-binding protein, is localized in the vitelline layer of sea urchin eggs. In this study, we have shown for the first time that sperm gangliosides are ligands for the intact glycosylated SBP. Using recombinant fragments of the SBP, the N-terminal heat shock protein 110-like domain was shown to be responsible for the binding. The intact SBP could bind various gangliosides, and the binding was sialidase-sensitive and inhibited by sialyllactose, thus indicating that it is the sialic acid-binding protein. Calcium and magnesium ions were not required but they did enhance the binding activity of SBP. The observation that bacterially expressed recombinant SBP and the sialidase-treated intact glycosylated SBP lost divalent cation-dependent enhancement of binding activity suggests that the sialylated carbohydrate moieties of the SBP may be involved in this property. Furthermore, the SBP was shown to bind sperm lipid rafts, in which gangliosides are enriched, and this binding was lost upon sialidase treatment of the lipid rafts. Finally, liposomes containing the ganglioside specifically inhibited fertilization. Taken together, these results allow us to identify SBP as a member of a new class of sialic acid-binding lectin belonging to the Hsp110 family, and indicate that SBP may be involved in interaction of sperm with the vitelline layer of the egg. 相似文献
30.
Neuronal differentiation-dependent expression of the disialic acid epitope on CD166 and its involvement in neurite formation in Neuro2A cells 总被引:4,自引:0,他引:4
We previously demonstrated that alpha2,8-linked disialic acid (diSia) residues occur in several glycoproteins of mammalian brains (Sato, C., Fukuoka, H., Ohta, K., Matsuda, T., Koshino, R., Kobayashi, K., Troy, F. A., II, and Kitajima, K. (2000) J. Biol. Chem. 275, 15422-15431). The role of the diSia epitope on these glycoproteins is not known, whereas the importance of the diSia epitope on glycolipids is well documented in neurite formation. In this study, we demonstrated that the diSia epitope (Neu5Acalpha2 --> 8Neu5Acalpha2 --> 3Gal) on glycoproteins, but not on glycolipids, is involved in neurite formation in a mouse neuroblastoma cell line, Neuro2A, based on the following lines of evidence. First, the amount of diSia epitope on glycoproteins increased during retinoic acid-induced neurite formation. Second, retinoic acid treatment primarily increased the diSia epitope on a 100-kDa glycoprotein. We identified this protein as CD166 (SC1), an immunoglobulin superfamily cell adhesion molecule involved in neurite extension. Third, a monoclonal antibody against the diSia epitope specifically inhibited neurite formation. We also demonstrated that alpha2,8-sialyltransferase III mRNA expression increased 1.7-fold after the induction of neurite formation, suggesting that alpha2,8-sialyltransferase III is responsible for formation of the diSia epitope on CD166. 相似文献