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911.
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Embryos of Xenopus laevis were exposed to 0.4 M LiCl for 5 min at various stages of development. The effect of lithium on the larval body pattern could be detected from the 2-cell to the late gastrula stage, but changed from reduction of posterior structures ("anteriorization") to reduction of anterior structures ("posteriorization") just after the 12th cleavage, the time of midblastula transition (MBT). Temporal coincidence of MBT with alteration of the effect of lithium was observed even with embryos derived from half-egg fragment, in which MBT occurs just after the 11th cleavage. These results suggest the existence of a mechanism for formation of the basic plan of the larval body whose function changes at MBT. Combinations of the pre- and post-MBT exposures to lithium induced marked posteriorization in most larvae, indicating that the basic plan is not irreversibly determined until MBT, but is fixed during post-MBT stages. 相似文献
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915.
T Imoto A Miyasaka R Ishima K Akasaka 《Comparative biochemistry and physiology. A, Comparative physiology》1991,100(2):309-314
1. A new substance that suppressed selectively the neural responses of the rat to sweet taste stimuli was isolated from the leaves of Gymnema sylvestre. 2. The substance was proved to be a peptide consisting of 35 amino acids and having a molecular weight of about 4,000. 3. The inhibitory effect on the sweet responses appeared after treating the tongue surface with the peptide at a concentration of more than 1 x 10(-6) M. 相似文献
916.
The cysteinyl residues in proteins had been S-2-aminoethylated with ethylenimine quantitatively. However, ethylenimine is now listed as a carcinogen and is no longer commercially available. A method of converting cysteinyl residues to S-2-aminoethyl derivatives quantitatively using 2-bromoethylamine under mild conditions was developed here. 相似文献
917.
Immunohistochemical localization of Met-enkephalin, Met-enkephalin-Arg6-Gly7-Leu8, Met-enkephalin-Arg6-Phe7 and Leu-enkephalin was studied in human adrenal medulla and pheochromocytomas at the light and electron microscopic levels. Both adrenal medulla and pheochromocytomas (4 adrenal, 1 extra-adrenal) showed scattered or clustered cells which contained all of the above peptides and suggested the production of proenkephalin A. The presence of these peptides predominantly in the secretory granules suggested that proenkephalin A is processed to final products mainly in the secretory granules. The localization of Met-enkephalin-Arg6-Gly7-Leu8 and Met-enkephalin-Arg6-Phe7 in cisternae of rough endoplasmic reticula indicated their actual production in pheochromocytomas. 相似文献
918.
Kiyoshi Hayashi Li Ying Satya Singh Satoshi Kaneko Satoru Nirasawa Tsuyoshi Shimonishi Yasushi Kawata Taiji Imoto Motomitsu Kitaoka 《Journal of Molecular Catalysis .B, Enzymatic》2001,11(4-6):811-816
The genes of family 3 β-glucosidase enzymes consist of five distinct regions; the N-terminal residues, an N-terminal catalytic domain, a nonhomologous region, a C-terminal domain of unknown function and the C-terminal residues. The β-glucosidase genes derived from Cellvibrio gilvus (CG) and Agrobacterium tumefaciens (AT) have been subjected to gene deletion, truncation and shuffling. The folding information was found to be distributed unevenly across the different regions based on the gene manipulation results. Chimeric enzymes with improved enzyme characteristics were obtained only by gene shuffling at the C-terminal domain. 相似文献
919.
Yoshimasa Suda Takashi Umeda Kiyotaka Watanebe Jun Kuroiwa Eiji Sasaki Toshiaki Tsukamoto Ippei Takahashi Masashi Matsuzaka Kaori Iwane Shigeyuki Nakaji 《Luminescence》2013,28(2):121-128
We examined changes in neutrophil function of soccer players over a 10‐month period and determined its effectiveness as an index for athlete physical condition. Subjects included 21 male professional Japanese soccer players. Data on body composition, myogenic enzymes and neutrophil function were obtained before and after 2 h of training at 3 investigation points: one week before opening season, at season mid‐point, and one week before the last game of the season. As a result, change ratios of myogenic enzyme levels before and after the 2‐hr training session at the third investigation point were significantly higher compared to the two other points. Reactive oxygen species production and phagocytic activity significantly increased after 2‐hr training session at point 1, although the extent of the increase became smaller over time and ROS production capability decreased significantly by point 3 assessment. Fatigue, especially muscle fatigue, chronically accumulated along with a gradual decrease in neutrophil immune function over the 10‐month season. Therefore, determination of neutrophil function can be used as a useful index to assess and understand an athlete's physical condition. Copyright © 2012 John Wiley & Sons, Ltd. 相似文献
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