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Charles A. Tyson Carol E. Green Susanna E. LeValley Robert J. Stephens 《In vitro cellular & developmental biology. Plant》1982,18(11):945-951
Summary Hepatocytes from livers of rats loaded by Fe-dextran treatment were isolated by an in situ collagenase perfusion technique
and evaluated for their biochemical, cytochemical, and morphological characteristics in cell culture. Iron loads 15 times
higher than in normal rat liver cells isolated in the same way were retained in the preparations with 40% present as hemosiderin.
A simple centrifugation-mathematical approach is described for the calculation of Fe content in the hepatocyte (95%) and reticuloendothelial
(5%) fractions in the isolates. The cells were cultured for 22 h without loss of protein synthesis capability or significant
changes in cell count, viability, endogenous glutamate-oxaloacetate transaminase (GOT) or Fe and were morphologically similar
in most respects to unloaded (normal) hepatocytes similarly cultured. Studies are in progress to assess the utility of these
preparations as a model for Fe mobilization from Fe-loaded animals.
This work is supported by National Institutes of Health Grants AM 25647-03 (M. Dawson, Principal Investigator) and GM 28158-01
(C. Tyson, Principal Investigator). The technical assistance of Mr. Jack E. Dabbs, Mr. Charles Hart, and Mr. Randy Douglas
is acknowledged. 相似文献
23.
Anionic peroxidase isoenzymes, separated on acrylamide gels, were examined in two flax genotrophs and in their reciprocal F2 hybrids. Isoenzyme 1 exhibited a significant difference in Rm between stem base and apex and there was a gradient of decreasing Rm and activity between base and apex. Isoenzyme 2 displayed only the activity gradient. The parents differed significantly in the Rm's and activities of isoenzymes 1 and 2, and the F2's showed complete dominance of the L parent for Rm, with activities being approximately intermediate. 相似文献
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Analysis of plasmodial fusion experiments shows that the timing of mitosis in the myxomycete Physarum polycephalum is controlled by a discontinuous (extreme relaxation) oscillator. Furthermore, there is no convincing evidence that mitosis and DNA synthesis are “downstream” from the control mechanism. 相似文献
26.
Eleni Panousopoulou Richard A. Tyson Till Bretschneider Jeremy B.A. Green 《Developmental biology》2013
Convergent extension (CE) is a conserved morphogenetic movement that drives axial lengthening of the primary body axis and depends on the planar cell polarity (PCP) pathway. In Drosophila epithelia, a polarised subcellular accumulation of PCP core components, such as Dishevelled (Dvl) protein, is associated with PCP function. Dvl has long been thought to accumulate in the mediolateral protrusions in Xenopus chordamesoderm cells undergoing CE. Here we present a quantitative analysis of Dvl intracellular localisation in Xenopus chordamesoderm cells. We find that, surprisingly, accumulations previously observed at mediolateral protrusions of chordamesodermal cells are not protrusion-specific but reflect yolk-free cytoplasm and are quantitatively matched by the distribution of the cytoplasm-filling lineage marker dextran. However, separating cell cortex-associated from bulk Dvl signal reveals a statistical enrichment of Dvl in notochord–somite boundary-(NSB)-directed protrusions, which is dependent upon NSB proximity. Dvl puncta were also observed, but only upon elevated overexpression. These puncta showed no statistically significant spatial bias, in contrast to the strongly posteriorly-enriched GFP-Dvl puncta previously reported in zebrafish. We propose that Dvl distribution is more subtle and dynamic than previously appreciated and that in vertebrate mesoderm it reflects processes other than protrusion as such. 相似文献
27.
Jian-Jun Jia Roni M Lahr Michael T Solgaard Bruno J Moraes Roberta Pointet An-Dao Yang Giovanna Celucci Tyson E Graber Huy-Dung Hoang Marius
R Niklaus Izabella A Pena Anne K Hollensen Ewan M Smith Malik Chaker-Margot Leonie Anton Christopher Dajadian Mark Livingstone Jaclyn Hearnden Xu-Dong Wang Yonghao Yu Timm Maier Christian K Damgaard Andrea J Berman Tommy Alain Bruno D Fonseca 《Nucleic acids research》2021,49(6):3461
28.
Jenna Morissette Sula Swart Tyson J. MacCormack Suzanne Currie Andrea J. Morash 《Journal of fish biology》2021,98(6):1585-1589
Typically, laboratory studies on the physiological effects of temperature are conducted using stable acclimation temperatures. Nonetheless, information extrapolated from these studies may not accurately represent wild populations living in thermally variable environments. The aim of this study was to compare the growth rate, metabolism and swimming performance of wild Atlantic salmon exposed to cycling temperatures, 16–21°C, and stable acclimation temperatures, 16, 18.5, 21°C. Growth rate, metabolic rate, swimming performance and anaerobic metabolites did not change among acclimation groups, suggesting that within Atlantic salmon's thermal optimum range, temperature variation has no effect on these physiological properties. 相似文献
29.
Michael?E?KonkelEmail author Derrick?R?Samuelson Tyson?P?Eucker Eric?A?Shelden Jason?L?O'Loughlin 《Cell communication and signaling : CCS》2013,11(1):100
Caveolae are 25–100 nm flask-like membrane structures enriched in cholesterol and glycosphingolipids. Researchers have proposed that Campylobacter jejuni require caveolae for cell invasion based on the finding that treatment of cells with the cholesterol-depleting compounds filipin III or methyl-β-cyclodextrin (MβCD) block bacterial internalization in a dose-dependent manner. The purpose of this study was to determine the role of caveolae and caveolin-1, a principal component of caveolae, in C. jejuni internalization. Consistent with previous work, we found that the treatment of HeLa cells with MβCD inhibited C. jejuni internalization. However, we also found that the treatment of HeLa cells with caveolin-1 siRNA, which resulted in greater than a 90% knockdown in caveolin-1 protein levels, had no effect on C. jejuni internalization. Based on this observation we performed a series of experiments that demonstrate that MβCD acts broadly, disrupting host cell lipid rafts and C. jejuni- induced cell signaling. More specifically, we found that MβCD inhibits the cellular events necessary for C. jejuni internalization, including membrane ruffling and Rac1 GTPase activation. We also demonstrate that MβCD disrupted the association of the β1 integrin and EGF receptor, which are required for the maximal invasion of epithelial cells. In agreement with these findings, C. jejuni were able to invade human Caco-2 cells, which are devoid of caveolae, at a level equal to that of HeLa cells. Taken together, the results of our study demonstrate that C. jejuni internalization occurs in a caveolae-independent manner. 相似文献
30.
Junko Shibayama Tyson G. Taylor Paul W. Venable Nathaniel L. Rhodes Ryan B. Gil Mark Warren Adam R. Wende E. Dale Abel James Cox Kenneth W. Spitzer Alexey V. Zaitsev 《PloS one》2013,8(3)