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991.
Kan Cheng Motohiro Hirose Xiupeng Wang Yu Sogo Atsushi Yamazaki Atsuo Ito 《Biochemical and biophysical research communications》2013,430(1):156-160
The initial attachment of mesenchymal stem cells (MSCs) to substrates and osteogenic differentiation are supported by culture on a hydroxyapatite substrate. Cell attachment areas of rat MSCs after 2 h of culture on hydroxyapatite substrates with various microstructures and the osteogenic differentiation activity thereafter were measured. The perceived outcome was that, after 2 h of culture, rat MSCs with a small attachment area would have a high osteogenic differentiation activity, whereas those with a large attachment area would have a low osteogenic differentiation activity. Furthermore, rat MSCs with a small attachment area had many cytoplasmic processes, while those with a large attachment area revealed clear stress fibers and focal contacts. These results suggest that cell attachment area of rat MSCs after 2 h of culture has a strong effect on the osteogenic differentiation of rat MSCs. Thus, the measurement of cell attachment area after 2 h of culture could become valuable for estimating the osteogenic differentiation activity of rat MSCs thereafter. 相似文献
992.
993.
A Chinese hamster (male, 1-month-old) was found to have a large nodular mass at the left mandible. The tumor appeared to replace the entire left mandible, extending from the third molar to the incisor. The tumor mass occupied most of the oral cavity to compress the tongue ventrally. Histologically, the neoplasm was composed of islands of chondrocytes with bizarre and enlarged nuclei which were surrounded by poorly differentiated mesenchymal cells. The tumor involved the falx cerebri to compress the frontal crest of the cerebrum. On the basis of histological features, this tumor was diagnosed as chondrosarcoma. 相似文献
994.
The ladybird beetle, Menochilus sexmaculatus (Fabricius), has a remarkable elytral colour polymorphism composed of black and red. In the present study, we investigated the effect of temperature on growth from the first instar larva to the pupal stage, as well as maternal morph types on the phenotypic expression of the elytral colour morph in a polymorphic population from Osaka, Japan. Female individuals of three different elytral colour morphs were collected from a wild population, and hatchlings from each female were divided into three groups, which were reared at three constant temperatures: 20 °C, 25 °C, and 30 °C. The phenotypic frequency of F1 adults indicated that the elytral morph type was determined by genetic factors, but not by growth temperatures. Namely, type A (almost black morph) was the most abundant in F1 from type A mothers (Male: 52.6%; Female: 32.3%); and types B (four small-dotted morph) and F (four medium-dotted morph) were the most abundant from type B (Male: 56.7%; Female: 53.3%) and type G (four larger-dotted morph) mothers (Male: 33.3%; Female: 31.3%), respectively. Therefore, the expression of elytral colour polymorphism in the Osaka, Japan population is likely to have a genetic basis contingent on parental morphs, rather than a phenotypic plasticity associated with growth temperatures. 相似文献
995.
Takuro Nakamura Toshikazu Ushijima Yukihito Ishizaka Minako Nagao Masami Aral Yukari Yamazaki Takatoshi Ishikawa 《Gene》1994,140(2):251-255
Point mutations of the Syrian hamster neu proto-oncogene have been observed in the transmembrane domain of N-nitroso-N-ethylurea(ENU)-induced neurofibromas, Genomic DNA derived from tumor tissue showed transforming activity in an NIH 3T3 assay and a cDNA clone of the hamster neu gene, containing the entire protein-coding region, was isolated from a transformant cDNA library. The encoded product is 92 and 88% homologous to the rat neu and the human c-erbB-2, respectively. The product of the mutated hamster neu gene showed increased autophosphorylation of Tyr residues. 相似文献
996.
We examined the effects of nitroglycerin (NGL) on cyclic AMP (c-AMP) and cyclic GMP (c-GMP) in the coronary artery at 15 sec, 30 sec, 60 sec, and 3 min after the injection of NGL (0.02 mg/kg i.v.) in vivo. The relaxant effect of NGL was significantly correlated to an increase in the c-GMP concentration of the coronary artery. The c-AMP concentrations were not significantly changed at any time during the time response studies. We observed purely in vivo that there was a close correlation between an increase in c-GMP concentration after treatment with NGL and relaxation of the canine coronary artery. This study suggests that intracellular c-GMP may be involved with the biologic events leading to smooth muscle relaxation. 相似文献
997.
Hog intestinal peroxidase and bovine lactoperoxidase exhibited similar spectral shifts upon pH alteration. From spectrophotometric titrations, it was found that there are hemelinked ionizations of pKa = 4.75 in intestinal peroxidase and pKa = 3.5 in lactoperoxidase. The apparent pKa (pKa′) increased with the increase in chloride concentration. The pKa′ vs log[Cl?] plots showed that the chloride forms complex with the acid forms of these enzymes with a dissociation constant (pK = 2.7). Although the dissociation constant (Kd) of the peroxidase-cyanide complexes is nearly independent of pH, cyanide competed with chloride in the acidic pH region. The slopes of logKd vs log[Cl?] were 1.0 for intestinal peroxidase and 0.5 for lactoperoxidase. The reaction of hydrogen peroxide with these peroxidases was also affected by chloride, similarly as the reaction with cyanide was. The results were explained by assuming that protonation occurs at the distal base and destroys the hydrogen bond between the base and a water molecule at the sixth coordinate position of the heme iron. 相似文献
998.
999.
K Sorimachi K Akimoto S Yamazaki A Niwa S Toda Y Yasumura 《Cell structure and function》1990,15(5):317-322
When macrophages derived from bone marrow were incubated with lignin derivative at 10 micrograms/ml, they formed multinucleated giant cells containing more than sixty nuclei. Cine-microscopic observation revealed that the formation of the giant cells was due to cell fusion. This phenomenon was specific for primary-cultured macrophages, and was not observed with either a macrophage cell line or established cell lines derived from other tissues. 相似文献
1000.