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991.
Ildikó Vidra Kálmán Simon László Institóris Ingeborg Csöregh Mátyás Czugler 《Carbohydrate research》1982,111(1):41-57
After hydrolysis of 1,6-dibromo-1,6-dideoxygalactitol (1) and 1,2:5,6-dianhydrogalactitol (2), 11 compounds were isolated, three of them as tritylated derivatives. Their structures were established on the basis of chemical evidence and, for four compounds, by X-ray diffraction. The main product of the hydrolysis of 1 was 3,6-anhydro-1-bromo-1-deoxy-dl-galactitol; the end-products of the hydrolysis of 2 were 1,5-anhydro-dl-galactitol, 2,5-anhydro-dl-altritol, and galactitol. 相似文献
992.
993.
C H H?kansson U Mercke B Sonesson N G Toremalm 《Acta morphologica Neerlando-Scandinavica》1976,14(4):291-297
The smooth musculature of the human trachea was studied and compared with earlier observations in the rabbit. The results may be summarized as follows: 1. The annular m. constrictor tracheae, previously observed in the rabbit, has also been identified in the human trachea. 2. Longitudinal muscle fibers outside the constrictor musculature were observed in man. These fibers are rudimentary and appear to be of no functional importance. 3. From a functional point of view, it appears justified to regard the outer tracheal musculature largely as a constrictor musculature. 4. The main function of the outer musculature of the trachea and the elastic cartilaginous arches is to maintain the stability of the tracheal wall. 5. The variation of the lumen of the trachea is mainly controlled by the m. trachealis in the pars membranacea. 相似文献
994.
995.
The contractile indices Vmax (maximum shortening velocity of the contractile element) and ARPD (power averaged rate of power density generation) which have been shown to be unaffected by alterations in preload and afterload were computed from isovolumic left ventricular pressure data of dogs. The two indices were tested for their ability to detect changes in contractility induced by a positive inotropic drug (Isoprenalin). Whereas a good correlation was found between ARPD and Vmax (coefficient of correlation 0,895) the index ARPD was more sensitive to augmentation of myocardial contractility; also because it is simpler to obtain computationally and more appropriate for the intact heart from a theoretical point of view. ARPD should be useful especially for quantification of acute changes in myocardial contractility. 相似文献
996.
Cultures of lapine articular chondrocytes were exposed to purified, human, recombinant interleukin-1 alpha or partially purified preparations of lapine, synovial, cytokines in the presence of [32P]orthophosphate. After 30 min incubation, phosphoproteins were extracted from the cells, separated by two-dimensional gel electrophoresis and visualized autoradiographically. Analysis of the autoradiograms revealed that interleukin-1 and the synovial factors produced marked changes in the pattern of protein phosphorylation. The synovial cytokines induced many of the same changes as interleukin-1, as well as a number of unique changes. This finding is consistent with the notion that, in addition to interleukin-1, synoviocytes secrete other cytokines which modulate the metabolism of chondrocytes. These data support the idea that signal transduction in chondrocytes responding to interleukin-1 involves the activation of one or more protein kinases. 相似文献
997.
CD15 monoclonal antibodies react with a phosphotyrosine-containing protein on the surface of human neutrophils 总被引:1,自引:0,他引:1
K M Skubitz J R Mendiola M S Collett 《Journal of immunology (Baltimore, Md. : 1950)》1988,141(12):4318-4323
mAb are useful as probes in the study of the roles of cell-surface components in neutrophil function. Many mAb that bind to human neutrophils react with the oligosaccharide lacto-N-fucopentaose III (CD15 antibodies). These antibodies, as well as several other widely used mAb reactive with human neutrophils, were employed to detect phosphoproteins present on these cells. Immunoprecipitation and subsequent gel electrophoresis of proteins from neutrophils labeled with [gamma-32P]ATP revealed a 170 to 190-kDa phosphoprotein specifically reactive with CD15 antibodies. No phosphoproteins were immunoprecipitated by CD11 or CD18 mAb. Phosphoamino acid analysis of the 170- to 190-kDa protein showed that it contained predominantly phosphotyrosine and a low level of phosphoserine. Recently, it was shown that this phosphoprotein is one of the major substrates of ecto-protein kinase activity on human neutrophils. The roles for the 170- to 190-kDa phosphoprotein and the ecto-protein kinase in neutrophil function remain to be determined. 相似文献
998.
C Greve W Opsahl K Reiser U Abbott C Kenney D Benson R Rucker 《Biochimica et biophysica acta》1988,967(2):275-283
The amounts of lysine-derived crosslinks in collagens from tendon, cartilage, intervertebral disc, and bone and changes in the composition of sternal cartilage glycosaminoglycans were estimated in two lines of chickens, a control-isogenic line and a line that develops scoliosis. In the scoliotic line, scoliosis first appears at 3-4 weeks and progressively increases in severity and incidence so that 90% of the birds express the lesion by week 10. We have reported previously that cartilage, tendon, and bone collagens from scoliotic birds are more soluble than corresponding collagens from normal birds. Herein, collagen crosslinking and altered proteoglycan metabolism are examined as possible mechanisms for the differences in collagen solubility. At 1 week of age there were fewer reducible crosslinking amino acids (hydroxylysinonorleucine, dihydroxylysinonorleucine, and lysinonorleucine) in collagens from sternal cartilage and tendon in the scoliotic line than in the isogenic line. However, by week 3 and at weeks 5 or 7 values were similar in both groups. The amounts of hydroxypyridinium in vertebral bone and intervertebral disc collagen were also similar in both groups of birds. Consequently, differences in collagen crosslinking do not appear to be a persistent developmental defect underlying the expression of scoliosis in the model. However, differences were observed in cartilage proteoglycans and glycosaminoglycans from the scoliotic line that were not present in cartilage from the isogenic line. The average molecular weight of the uronide-containing glycosaminoglycans was 30% less in the scoliotic line than in the isogenic line, i.e., 12,000 compared to 18,000. The size distribution of cartilage proteoglycans from the scoliotic line also differed from that of proteoglycans from the isogenic line.(ABSTRACT TRUNCATED AT 250 WORDS) 相似文献
999.
1000.
Effect of Phosphate on the Corrosion of Carbon Steel and on the Composition of Corrosion Products in Two-Stage Continuous Cultures of Desulfovibrio desulfuricans 总被引:9,自引:4,他引:5 下载免费PDF全文
Paul J. Weimer Margaret J. Van Kavelaar Charles B. Michel Thomas K. Ng 《Applied microbiology》1988,54(2):386-396
A field isolate of Desulfovibrio desulfuricans was grown in defined medium in a two-stage continuous culture apparatus with different concentrations of phosphate in the feed medium. The first state (V1) was operated as a conventional chemostat (D = 0.045 h−1) that was limited in energy source (lactate) or phosphate. The second stage (V2) received effluent from V1 but no additional nutrients, and contained a healthy population of transiently starved or resting cells. An increase in the concentration of phosphate in the medium fed to V1 resulted in increased corrosion rates of carbon steel in both V1 and V2. Despite the more rapid corrosion observed in growing cultures relative to that in resting cultures, corrosion products that were isolated under strictly anaerobic conditions from the two culture modes had similar bulk compositions which varied with the phosphate content of the medium. Crystalline mackinawite (Fe9S8), vivianite [Fe3(PO4)2 · 8H2O], and goethite [FeO(OH)] were detected in amounts which varied with the culture conditions. Chemical analyses indicated that the S in the corrosion product was almost exclusively in the form of sulfides, while the P was present both as phosphate and as unidentified components, possibly reduced P species. Some differential localization of S and P was observed in intact corrosion products. Cells from lactate-limited, but not from phosphate-limited, cultures contained intracellular granules that were enriched in P and Fe. The results are discussed in terms of several proposed mechanisms of microbiologically influenced corrosion. 相似文献