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41.
42.
This study evaluated the body composition (underwater weighing) and cardiorespiratory function (VO(2)max and O(2)debt max measured by the treadmill exercise test) in 12 members of the women's volleyball team (mean age 17.4 years) and 11 members of the women's basketball team (mean age 17.6 years) that won the championship in the Japan Inter-high School Meeting. We also examined differences in the physical abilities between the members of the top teams of different events. The following results were obtained. (1) The mean values of the height and body weight were 168.7+/-5.89 cm and 59.7+/-5.73 kg in the volleyball players and 166.5+/-7.87 cm and 58.8+/-6.85 kg in the basketball players. (2) The mean %Fat was 18.4+/-3.29% in the volleyball players and 15.7+/-5.05% in the basketball players, and was similar to the reported values in elite adult players. (3) The mean VO(2)max was 2.78+/-0.32 L x min(-1) (46.5+/-2.90 ml x kg(-1) x min(-1)) in the volleyball players and 3.32+/-0.31 L x min(-1) (56.7+/-4.17 ml x kg(-1) x min(-1)) in the basketball players, and was similar to the reported values in elite adult players. (4) The mean O(2)debt max was 6.18+/-1.15 L (103.2+/-12.40 ml x kg(-1)) in the volleyball players and 7.92+/-1.80 L (134.3+/-23.24 ml x kg(-1)) in the basketball players. These values were 2.6 times and 3.3 times as high as the average values in high school students in general. (5) No significant difference was observed in any measured item of the physique, skinfold thickness, or body composition between the volleyball players and basketball players. (6) The VO(2)max and O(2)debt max were 22% and 28% higher in the basketball players than in the volleyball players.From these results, the female volleyball players and basketball players evaluated in this study had the physical abilities needed to win the championship in the Japan Inter-high School Meets, i.e. a large FFM and excellent aerobic and anaerobic work capacities. Also, basketball appears to require higher aerobic and anaerobic work capacities than volleyball.  相似文献   
43.
Two novel isoflavonoid dimers presumably originating from 2'-hydroxygenistein, 5,7,4'-trihydroxycoumaranochroman-4-one-(3-->5"')-5",7",2"'4"'- tetrahydroxyisoflavone (1, lupinalbisone A) and 5,7,4'-trihydroxycoumaranochroman-4-one-(3-6")-5",7",2"',4"'-te trahydroxyisoflavone (2, lupinalbisone B) were isolated from the roots of Lupinus albus L., and their structures involving relative stereochemistry were elucidated by spectroscopic methods. Using horse radish peroxidase and 2'-hydroxygenistein (3) as the substrate revealed the formation of these dimers together with 5,7,4'-trihydroxycoumaronochromone (4, lupinalbin A). Dimerization of 3 caused a remarkable increase of antifungal activity.  相似文献   
44.
Despite groundbreaking work to identify numerous proteins and to focus attention on molecular interactions, the mechanism of calcium-triggered membrane fusion remains unresolved. A major difficulty in such research has been the many overlapping and interacting membrane trafficking steps in the secretory pathway, including those of membrane retrieval. Identifying the specific role(s) of a given protein, beyond its general involvement in exocytosis, has therefore proven problematic. Furthermore, the power of time-resolved optical and electrophysiological assays can be best applied to testing the function of known proteins rather than to the identification of unknown, critical membrane components. The identification of essential membrane constituents requires combined biochemical (molecular) and functional (physiological) analyses. A fully functional, stage-specific physiological membrane preparation would be one direct approach to dissecting the calcium-triggered fusion steps of regulated exocytosis. Herein we review our use of specific minimal membrane preparations consisting of fully primed and docked secretory vesicles, or the isolated vesicles themselves, and characterize the late events of exocytosis, with an aim towards identification of essential molecular components. We have established a functional definition of the fusion complex and its activation by calcium, based on our kinetic analyses. Together with a variety of biochemical and alternate functional assays, we have tested whether the SNARE core complex that is present in our vesicle membranes satisfies the criteria of the functionally defined fusion complex. Rather than a direct fusogenic role, the SNARE complex may promote the calcium sensitivity of fusion, possibly by defining or delimiting a localized, focal membrane fusion site that ensures rapid and efficient exocytosis in vivo.  相似文献   
45.
Thrombopoietin (TPO) is a cytokine that primarily stimulates megakaryocytopoiesis and thrombopoiesis. TPO has a unique C-terminal tail peptide of about 160 amino acids that consists mostly of hydrophilic residues and contains six N-linked sugar chains. In order to investigate the biological function of the C-terminal domain, two series of mutations were performed. One is systematic truncation from the C terminus. Another is elimination of N-glycosylation sites in the C-terminal domain by Asn to Gln mutations. After the mutant proteins were expressed by mammalian cells, it was found that the elimination of the N-linked sugar sites did not affect the biological activity, whereas truncation of the C-terminal domain resulted in elevation of in vitro activity up to 4-fold. The C-terminal peptide itself was found to inhibit the in vitro activity. Moreover, both the C-terminal truncation and the elimination of the N-glycosylation sites decreased the secretion level progressively down to (1)/(10) that of wild type, and the amount of the mutant left in the cell increased. The N-glycosylation in the C-terminal region was found to be important for secretion of TPO. Among six N-glycosylation sites in the C-terminal region, two locations, Asn-213 and Asn-234, were found to be critical for secretion, and two other locations, Asn-319 and Asn-327, did not affect the secretion.  相似文献   
46.
We recently reported that angiotensin II (AngII) biphasically activates the JAK/STAT pathway and induces delayed phosphorylation of STAT3 in the late stage (120 min) in cardiomyocytes. This study was designed to determine the mechanism of delayed phosphorylation of STAT3. Conditioned medium prepared from AngII-stimulated cardiomyocytes could reproduce the tyrosine phosphorylation of STAT3 at 5 min. This delayed phosphorylation was almost completely inhibited by anti-gp130 blocking antibody RX435, but not by TAK044 (ET-A/B-R antagonist), prazosin, or propranolol. AngII induced phosphorylation of gp130 in the late stage, which was temporally in parallel with the delayed phosphorylation of STAT3. AngII augmented IL-6, CT-1, and LIF mRNA expression at 30-60 min, but not CNTF expression. AngII increased IL-6 protein levels by 3-fold in the conditioned media at 2 h compared with the control. These findings indicated that AngII-induced delayed activation of STAT3 is caused by autocrine/paracrine secreted IL-6 family cytokines.  相似文献   
47.
Two nitro compounds, 2-(4-methoxyphenyl)-1-nitroethane named as lysichitalexin and 2-(4-hydroxyphenyl)-1-nitroethane were isolated as stress metabolites from the leaves of Lysichitum americanum Hultén and St. John treated with cupric chloride. Their structures were determined by spectroscopic methods and chemical reactions. The former compound showed antifungal activities against Fusarium oxysporum and Cladosporium herbarum. Both compounds were isolated for the first time from this species and the former was isolated from natural sources for the first time. This is the first report on stress metabolites from a member of the Araceae.  相似文献   
48.
Clinical isolates of measles virus (MV) use signaling lymphocyte activation molecule (SLAM) as a cellular receptor, whereas vaccine and laboratory strains may utilize the ubiquitously expressed CD46 as an additional receptor. MVs also infect, albeit inefficiently, SLAM(-) cells, via a SLAM- and CD46-independent pathway. Our previous study with recombinant chimeric viruses revealed that not only the receptor-binding hemagglutinin (H) but also the matrix (M) protein of the Edmonston vaccine strain can confer on an MV clinical isolate the ability to grow well in SLAM(-) Vero cells. Two substitutions (P64S and E89K) in the M protein which are present in many vaccine strains were found to be responsible for the efficient growth of recombinant virus in Vero cells. Here we show that the P64S and E89K substitutions allow a strong interaction of the M protein with the cytoplasmic tail of the H protein, thereby enhancing the assembly of infectious particles in Vero cells. These substitutions, however, are not necessarily advantageous for MVs, as they inhibit SLAM-dependent cell-cell fusion, thus reducing virus growth in SLAM(+) B-lymphoblastoid B95a cells. When the cytoplasmic tail of the H protein is deleted, a virus with an M protein possessing the P64S and E89K substitutions no longer grows well in Vero cells yet causes cell-cell fusion and replicates efficiently in B95a cells. These results reveal a novel mechanism of adaptation and attenuation of MV in which the altered interaction of the M protein with the cytoplasmic tail of the H protein modulates MV growth in different cell types.  相似文献   
49.
Levels of lysophosphatidic acid (LPA), an important phospholipid mediator, in serum and ascitic fluid from ovarian cancer patients were shown to be higher than those from healthy women and from patients with other type of cancer, respectively. Although LPA in human serum seems mainly to be generated by lysophospholipase D (lysoPLD), the source and pathway for LPA in the ascitic fluid remain still obscure. In this study, we examined whether lysoPLD activity producing bioactive LPA in human peritoneal fluid was significantly elevated under pathological statuses. Lysophospholipase D activity in human peritoneal fluids was measured by quantifying choline released from exogenous lysophosphatidylcholine on their incubation at 37 degrees C. We also compared the activity of lysoPLD in sera from patients with different gynecologic diseases. We found relatively high lysoPLD activity in peritoneal fluids from patients with ovarian cancer, dermoid cyst or mucinous cystadenoma, whereas there were no significant differences in the serum lysoPLD activity among clinical groups and healthy subjects. The lysoPLD in the peritoneal fluid was found to have similar substrate specificity and metal ion requirement to those of serum lysoPLD, that has been identified as autotaxin, a tumor cell-motility stimulating protein. Our results suggest that increased lysoPLD activity in peritoneal fluid from patients with certain gynecologic tumors might be relevant to its potential of tumor progression.  相似文献   
50.
Pseudomonas jessenii EC-S101 produced hyphal branching-inducing and mitosis-accelerating factors active towards Peronosporomycetes, Aphanomyces cochlioides hyphae. In searching for the active substances, EtOAc-solubles extracted from EC-S101-cultured solid medium were fractionated under the guidance of a paper disc assay using an A. cochlioides mycelium. Two active substances were subsequently isolated and the structure was elucidated by spectroscopic analysis to be (+)-4,5-didehydroacaterin (1) and 3-[(1R)-hydroxyhexyl]-5-methylene-2(5H)-furanone (2), both of which accelerated the mitotic process of A. cochlioides hyphae along with excessive branching at 1.0 microg per disc. These compounds are likely to affect the morphophysiological development of certain eukaryotic organisms in the terrestrial ecosystem.  相似文献   
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