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The cause of the pregnancy condition preeclampsia (PE) is thought to be endothelial dysfunction caused by oxidative stress. As abnormal glucose tolerance has also been associated with PE, we use a fluorinated-mimic of this metabolite to establish whether any oxidative damage to lipids and proteins in the erythrocyte membrane has increased cell membrane permeability. Data were acquired using 19F Dynamic-NMR (DNMR) to measure exchange of 3-fluoro-3-deoxyglucose (3-FDG) across the membrane of erythrocytes from 10 pregnant women (5 healthy control women, and 5 from women suffering from PE). Magnetisation transfer was measured using the 1D selective inversion and 2D EXSY pulse sequences, over a range of time delays. Integrated intensities from these experiments were used in matrix diagonalisation to estimate the values of the rate constants of exchange and membrane permeability. No significant differences were observed for the rate of exchange of 3-FDG and membrane permeability between healthy pregnant women and those suffering from PE, leading us to conclude that no oxidative damage had occurred at this carrier-protein site in the membrane. 相似文献
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Molecular characterization of glutamic acid/glutamine-rich secretory proteins from rat submandibular glands 总被引:3,自引:0,他引:3
L Mirels G S Bedi D P Dickinson K W Gross L A Tabak 《The Journal of biological chemistry》1987,262(15):7289-7297
A family of abundant rat submandibular gland secretory proteins has been identified in glandular extracts and characterized. By amino acid analysis these proteins contain approximately 35% glutamic acid and glutamine plus 14% proline. They have therefore been named "Glx-rich proteins" (GRP). Plasmids containing cDNAs for a GRP have been isolated from a cDNA library prepared from rat submandibular gland poly(A)+RNA. The nucleotide sequence of these cDNAs have been determined. Approximately half of the protein coding sequence is composed of a 23-residue tandem repeat which is repeated five times. The first four repeats are highly conserved at both the nucleotide and amino acid level and consist of the prototype sequence: Asn-Gln-Glu-Pro-Pro-Ala-Thr-Ser-Gly-Ser-Glu-Glu-Glu-Gln-Gln-Gln-Gln-Glu- Pro-Thr-Gln-Ala-Glu. The expression of GRP appears to be specific to the submandibular gland. In vitro assays demonstrate that the GRP have a marked affinity for hydroxyapatite. This suggests that GRP may play a role in the formation of the protective acquired pellicle at the saliva-tooth interface. 相似文献
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Summary The use of reticulated polyurethane foam as a support material for the immobilization of methanogenic associations and its application to the anaerobic treatment of fine particulate solid wastes was investigated. The colonization of polyurethane support particles in a continuous upflow reactor fed on a mixture of acetate, propionate and butyrate, was both rapid and dense. The combination of rumen microorganisms and colonized support particles in a two-phase digester resulted in an efficient anaerobic decomposition of papermill sludge. 相似文献