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The relationship between donor cell cycle and the developmental ability of somatic cell nuclear transfer (SCNT) embryos has not fully been elucidated. Donor cells that are usually prepared by serum starvation or confluent-cell culture for SCNT represent a heterogeneous population that includes mainly G0 phase cells, other cells in different phases of the cell cycle and apoptotic cells. In this study, we compared the developmental ability of porcine SCNT embryos reconstructed from G0 phase cells (G0-SCNT embryos) and strictly synchronized-G1 phase cells (G1-SCNT embryos), and examined the developmental rates and timing of first DNA synthesis. The G0 phase cells were synchronized by confluent culture, and the G1 phase cells were prepared from actively dividing M phase cells. The G1-SCNT embryos showed a significantly higher (P<0.05) developmental rate to the blastocyst stage per cleaved embryo (59%) than the G0-SCNT embryos (43%). Moreover, initiation of first DNA synthesis and cleavage occurred significantly earlier in the G1-SCNT embryos than in the G0-SCNT embryos. Delay of initiation of first DNA synthesis in the SCNT embryos by aphidicolin resulted in decreased developmental rates to the blastocyst stage without any effect on cleavage rates. Our data demonstrates that synchronized-G1 phase cells can be used as donor cells for SCNT embryos and that earlier initiation of first DNA synthesis may be important for subsequent development of SCNT embryos. The SCNT system using G1-synchronized cells, in terms of their highly uniform and viable cell states, can be useful for studying the reprogramming processes and embryonic development of SCNT embryos.  相似文献   
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Three dogs were examined because of episodes of recurrent pruritic dermatitis in the spring, the season of Japanese cedar (Cryptomeria japonica, CJ) pollination in Japan. The dogs were shown to be sensitive to CJ pollen allergen using intradermal testing and antigen-specific IgE measurement. Fluorometric enzyme-linked immunosorbant assay (ELISA) showed increased concentrations of IgE specific to Cry j 1 and a negative result for Cry j 2 in the three dogs. The concentrations of IgE specific to Cry j 1 during the season of CJ pollination were higher than the concentrations found during the off-season in all the dogs, and the variation in the concentrations correlated with the variation in clinical signs. Peripheral blood mononuclear cells showed apparent proliferative responses to crude CJ pollen antigen and Cry j 1 during CJ pollination season. These findings indicated that Cry j 1 was the major allergen recognized by IgE and lymphocytes and resulted in the development of type I hypersensitivity to CJ pollen allergen in these atopic dogs.  相似文献   
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An automatic counting method was developed for fish blood cells using a fluorescent dye, 3, 3-dihexyloxacarbocyanine (DiOC (6)(3)), that selectively stain lipid bilayers in living cells. In the present study, the DiOC(6)(3) method was applied to quail (Cotumix cotumix japonica) blood cells. After quail blood cells were stained with DiOC(6)(3), absolute counts and relative proportions of erythrocytes, granulocytes, monocytes, and lymphocytes plus thrombocytes in whole blood were obtained by means of flow cytometry (FC). The number of each cell types by the FC was in good agreement with those counted microscopically. This method will offer new possibilities for routine blood cell counting for avian medicine.  相似文献   
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There have been diverse reports on the effects of diazepam on cardiac contractility. The purpose of this study was to examine whether diazepam modifies the inotropic response elicited by histamine on an isolated guinea-pig papillary muscle. The responses of electrically driven papillary muscle to histamine and cyclic AMP-related inotropic agents were recorded in the absence and in the presence of diazepam. Histamine and forskolin, which directly stimulate adenylate cyclase, significantly increased the contractile force in the papillary muscle in a concentration-dependent manner. A histaminergic H2-receptor antagonist, cimetidine, but not a H1-receptor antagonist, diphenhydramine, at 10 μ M produced a rightward shift in the concentration-response curve for histamine. Diazepam (10 μ M ) shifted the concentration-response curve for histamine and forskolin to the left by 1.8 and 1.6 times, respectively. Neither a central type (fulmazenil) nor a peripheral type (PK11195) of benzodiazepine receptor antagonist modified the effect of diazepam on the histaminergic-evoked contraction. Phosphodiesterase blockade by 3-isobutyl-1-methylxanthine shifted the concentration-dependent curve for histamine to the left. A combination of 3-isobutyl-1-methylxanthine also produced a leftward shift of the curve. However, there was no significant difference between the 3-isobutyl-1-methylxanthine only group and the combination group. These results indicate that diazepam potentiates the positive inotropic effect produced by histamine, probably mediated via an increase in cyclic AMP levels induced by histamine.  相似文献   
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 The reaction behavior and kinetics of lignin model compounds were studied in supercritical methanol with a batch-type supercritical biomass conversion system. Guaiacol, veratrole, 2,6-dimethoxyphenol, and 1,2,3-trimethoxybenzene were used as model compounds for aromatic rings in lignin. In addition, 5-5, β-1, β-O-4, and α-O-4 types of dimeric lignin model compounds were used as representatives of linkages in lignin. As a result, aromatic rings and 5-5 (biphenyl)-type structures were stable in supercritical methanol, and the β-1 linkage was not cleaved in the β-1-type structure but converted rapidly to stilbene. On the other hand, β-ether and α-ether linkages of β-O-4 and α-O-4 lignin model compounds were cleaved rapidly, and these compounds decomposed to some monomeric compounds. Phenolic compounds were found to be more reactive than nonphenolic compounds. These results indicate that cleavages of ether linkages mainly contribute to the depolymerization of lignin, whereas condensed linkages such as the 5-5 and β-1 types are not cleaved in supercritical methanol. Therefore, it is suggested that the supercritical methanol treatment effectively depolymerizes lignin into the lower-molecular-weight products as a methanol-soluble portion mainly by cleavage of the β-ether structure, which is the dominant linkage in lignin. Received: December 19, 2001 / Accepted: April 30, 2002 Acknowledgments This research has been done under the research program for the development of technologies for establishing an ecosystem based on recycling in rural villages for the twenty-first century from the Ministry of Agriculture, Forestry and Fisheries, Japan; by a Grant-in-Aid for Scientific Research (B)(2) (no.12460144, 2001.4–2003.3) from the Ministry of Education, Culture, Sports, Science and Technology, Japan; and under the research program from Kansai Research Foundation for Technology Promotion, Japan. The authors thank them for their financial support. This study was presented in part at the 45th Lignin Symposium, Ehime, Japan, October 2000 and the 52nd Annual Meeting of the Japan Wood Research Society, Gifu, Japan, April 2002 Correspondence to:S. Saka  相似文献   
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The chemical conversion of Japanese beech (Fagus crenata Blume) in water-added supercritical methanol was studied for a wide range of water content using a batch-type reaction vessel to obtain chemicals from lignocellulosics. It was consequently found that addition of water enhanced the decomposition of wood cell wall components; cellulose, hemicelluloses, and lignin. In cases of high water content, however, it resulted in low solubility of lignin-derived products causing an increase in the mass of the residue. The water content was thus optimized to be around 10% (v/v) for the decomposition of wood. Concomitantly, the yields and selectivity of the chemicals from wood could be regulated by the addition of water, especially for the lignin-derived products. As a result, the monomeric compounds of lignin, coniferyl alcohol and sinapyl alcohol, were recovered as their γ-methyl ethers in the presence of water in higher yields than those obtained without addition of water.  相似文献   
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