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991.
Annett Richter Irmgard Seidl-Adams Tobias G. Köllner Claudia Schaff James H. Tumlinson Jörg Degenhardt 《Planta》2015,241(6):1351-1361
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Larsson S Rydén T Holst U Oredsson S Johansson M 《Bulletin of mathematical biology》2008,70(8):2177-2194
Increasing the knowledge of various cell cycle kinetic parameters, such as the length of the cell cycle and its different
phases, is of considerable importance for several purposes including tumor diagnostics and treatment in clinical health care
and a deepened understanding of tumor growth mechanisms. Of particular interest as a prognostic factor in different cancer
forms is the S phase, during which DNA is replicated. In the present paper, we estimate the DNA replication rate and the S
phase length from bromodeoxyuridine-DNA flow cytometry data. The mathematical analysis is based on a branching process model,
paired with an assumed gamma distribution for the S phase duration, with which the DNA distribution of S phase cells can be
expressed in terms of the DNA replication rate. Flow cytometry data typically contains rather large measurement variations,
however, and we employ nonparametric deconvolution to estimate the underlying DNA distribution of S phase cells; an estimate
of the DNA replication rate is then provided by this distribution and the mathematical model. 相似文献
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Chlamydomonas reinhardtii accumulates lipids under complete nutrient starvation conditions while overall growth in biomass stops. In order to better understand biochemical changes under nutrient deprivation that maintain production of algal biomass, we used a lipidomic assay for analyzing the temporal regulation of the composition of complex lipids in C. reinhardtii in response to nitrogen and sulfur deprivation. Using a chip-based nanoelectrospray direct infusion into an ion trap mass spectrometer, we measured a diversity of lipid species reported for C. reinhardtii, including PG phosphatidylglycerols, PI Phosphatidylinositols, MGDG monogalactosyldiacylglycerols, DGDG digalactosyldiacylglycerols, SQDG sulfoquinovosyldiacylglycerols, DGTS homoserine ether lipids and TAG triacylglycerols. Individual lipid species were annotated by matching mass precursors and MS/MS fragmentations to the in-house LipidBlast mass spectral database and MS2Analyzer. Multivariate statistics showed a clear impact on overall lipidomic phenotypes on both the temporal and the nutrition stress level. Homoserine-lipids were found up-regulated at late growth time points and higher cell density, while triacyclglycerols showed opposite regulation of unsaturated and saturated fatty acyl chains under nutritional deprivation. 相似文献
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Lukas Martin Rebecca De Santis Patrick Koczera Nadine Simons Hajo Haase Lena Heinbockel Klaus Brandenburg Gernot Marx Tobias Schuerholz 《PloS one》2015,10(11)
Heparanase is an endo-β-glucuronidase that cleaves heparan sulfate side chains from their proteoglycans. Thereby, heparanase liberates highly potent circulating heparan sulfate-fragments (HS-fragments) and triggers the fatal and excessive inflammatory response in sepsis. As a potential anti-inflammatory agent for sepsis therapy, peptide 19–2.5 belongs to the class of synthetic anti-lipopolysaccharide peptides; however, its activity is not restricted to Gram-negative bacterial infection. We hypothesized that peptide 19–2.5 interacts with heparanase and/or HS, thereby reducing the levels of circulating HS-fragments in murine and human sepsis. Our data indicate that the treatment of septic mice with peptide 19–2.5 compared to untreated control animals lowers levels of plasma heparanase and circulating HS-fragments and reduces heparanase activity. Additionally, mRNA levels of heparanase in heart, liver, lung, kidney and spleen are downregulated in septic mice treated with peptide 19–2.5 compared to untreated control animals. In humans, plasma heparanase level and activity are elevated in septic shock. The ex vivo addition of peptide 19–2.5 to plasma of septic shock patients decreases heparanase activity but not heparanase level. Isothermal titration calorimetry revealed a strong exothermic reaction between peptide 19–2.5 and heparanase and HS-fragments. However, a saturation character has been identified only in the peptide 19–2.5 and HS interaction. In conclusion, the findings of our current study indicate that peptide 19–2.5 interacts with heparanase, which is elevated in murine and human sepsis and consecutively attenuates the generation of circulating HS-fragments in systemic inflammation. Thus, peptide 19–2.5 seems to be a potential anti-inflammatory agent in sepsis. 相似文献
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