The Experts below are selected from a list of 459 Experts worldwide ranked by ideXlab platform
Julian N. Kanfer - One of the best experts on this subject based on the ideXlab platform.
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Glycerophosphorylcholine phosphocholine phosphodiesterase activity during the differentiation of glial progenitor cells
Journal of Neuroscience Research, 1993Co-Authors: M. Monge, J. Yuan, Bernard Zalc, F Cabon, Julian N. KanferAbstract:O-2A progenitor cells were grown in medium containing either 1% or 10% fetal calf serum (FCS) for 4 weeks. The cells in 1% FCS were 75% oligodendrocytes by 3 weeks in culture. The cell population was so overgrown with astrocytes in the 10% medium that an accurate estimate of cell number could not be made. The activities of Glycerophosphorylcholine phosphocholine phosphodiesterase (GPC-PC-PdE), p-nitrophenylphosphorylcholine phosphodiesterase (pNPPC-PC-PdE), and ceramide UDP galactose galactosyl transferase (CGalT) were barely detectable in the cells grown in 10% FCS. The activities of these 3 enzymes were low in the cells grown in 1% FCS for the first 2 weeks and then all 3 increased manyfold. These observations reinforce the evidence previously accrued showing that these two phosphodiesterase activities (GPC-PC-PdE and pNPPC-PC-PdE) are markers of oligodendroglial cells as well as myelin. In contrast, Glycerophosphorylcholine choline phosphodiesterase (GPC-C-PdE) activities were present in cells grown in both 1% and 10% FCS. © 1993 Wiley-Liss, Inc.
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Glycerophosphorylcholine phosphocholine phosphodiesterase activity in cultured oligodendrocytes, astrocytes, and central nervous tissue of dysmyelinating rodent mutants
Journal of neuroscience research, 1992Co-Authors: J. Yuan, D. G. Mccartney, M. Monge, A. Espinosa De Los Monteros, Bernard Zalc, J. De Vellis, Julian N. KanferAbstract:The levels of GPC phosphocholine phosphodiesterase, pNP phosphocholine phosphodiesterase, CNPase, and UDP galactose: ceramide galactosyltransferase activities were estimated with pure cultures of oligodendrocytes and astrocytes; mixed primary glial cells cultures; C-6 cells; and CNS tissue of the dysmyelinating md rat, the jimpy mouse, and the quaking mouse. The highest activity of GPC and pNP phosphocholine phosphodiesterases as with CNPase and C gal T was found in the pure cultured oligodendrocytes. C-6 cells had very low or undetectable activities for these two phosphodiesterases but possessed very high CNPase activity. The activity of GPC phosphocholine phosphodiesterase was significantly decreased in the CNS tissue of the md rat and the jimpy and the quaking mouse. Similar reductions were observed for the pNP phosphocholine phosphodiesterase, CNPase, and C gal T activities. The selective cellular enrichment in oligodendrocytes of the GPC phosphocholine phosphodiesterase activity and decreases of its activity in three dysmyelinating mutants in the same ratio as for CNPase and C gal T suggest that GPC phosphocholine phosphodiesterase is a myelin marker enzyme and it may reflect the quantity of myelin and oligodendrocyte present.
Vinod Bhakuni - One of the best experts on this subject based on the ideXlab platform.
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Leishmania donovani: Metabolite mapping of promastigotes using proton nuclear magnetic resonance spectroscopy
Molecular and Cellular Biochemistry, 1996Co-Authors: U.k. Singha, Vinod BhakuniAbstract:Proton nuclear magnetic resonance spectroscopy was used for studying the intracellular metabolite profile of promastigotes of Leishmania donovani . The major intracellular metabolites observed in the promastigotes were acetate, alanine, succinate, glycine, α-Glycerophosphorylcholine, acetoacetate, arginine and ethanol. A comparative study of the intracellular metabolite profile of promastigotes of different strains of L. donovani showed that, all the major intracellular metabolites were present in promastigotes of different strains. A quantitative estimation of metabolites showed a strain specific (Finger print) metabolite profile which can be used for strain/species identification/differentiation.
Fushing Hsieh - One of the best experts on this subject based on the ideXlab platform.
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characterization of the metabolic actions of crude versus dispersed oil in salmon smolts via nmr based metabolomics
Aquatic Toxicology, 2009Co-Authors: Chingyu Lin, Brian S Anderson, Bryn M Phillips, Andrew C Peng, Sara L Clark, Jennifer P Voorhees, Marida J Martin, James Mccall, Charles R Todd, Fushing HsiehAbstract:With maritime transport of crude oil from Alaska to California, there is significant potential for a catastrophic spill which could impact migrating salmon. Therefore, this study compared the lethal and sublethal metabolic actions of the water-accommodated fraction (WAF) and the chemically enhanced WAF (CEWAF, via Corexit 9500) of Prudhoe Bay crude oil in smolts of Chinook salmon (Onchorhyncus tshawytscha). After 96-h exposure to the CEWAF, the resulting LC50 was some 20 times higher (i.e., less toxic) than that of the WAF. Muscle and liver samples from surviving fish were collected and low-molecular weight metabolites were analyzed using one-dimensional (1)H and projections of two-dimensional (1)H J-resolved NMR. Principal component analysis (PCA), employed to analyze NMR spectra and identify most variance from the samples, revealed age-related metabolic changes in the fish within the replicated studies, but few consistent metabolic effects from the treatments. However, ANOVA results demonstrated that the dose-response metabolite patterns are both metabolite- and organ-dependent. In general, exposure to either WAF or CEWAF resulted in an increase of amino acids (i.e., valine, glutamine and glutamate) and a decrease of both organic osmolytes (i.e., Glycerophosphorylcholine) and energetic substrates (i.e., succinate). The simultaneous increase of formate and decrease of Glycerophosphorylcholine in the liver, or the decrease of Glycerophosphorylcholine in muscle, may serve as sensitive sublethal biomarkers for WAF or CEWAF exposures, respectively. In conclusion, dispersant treatment significantly decreased the lethal potency of crude oil to salmon smolts, and the NMR-based metabolomics approach provided a sensitive means to characterize the sublethal metabolic actions.
Zoltan H Endre - One of the best experts on this subject based on the ideXlab platform.
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regional proton nuclear magnetic resonance spectroscopy differentiates cortex and medulla in the isolated perfused rat kidney
Magnetic Resonance Materials in Physics Biology and Medicine, 1997Co-Authors: Gary Cowin, I A Leditschke, Stuart Crozier, Ian M Brereton, Zoltan H EndreAbstract:Volume-localized proton nuclear magnetic resonance spectroscopy was used as an assay of regional biochemistry in the isolated perfused rat kidney. This model eliminated artifacts caused by respiratory and cardiac motion experiencedin vivo. Immersion of the kidney under its venous effluent reduced the susceptibility artifacts evoked by tissue-air interfaces. The rapid acquisition with relaxation enhancement imaging sequence was used for scout imaging. This gave excellent spatial resolution of the cortex, outer medulla, and inner medulla. Spectra were then acquired in 10 minutes using the volume-selective multipulse spectroscopy sequence from voxels with a volume of approximately 24 μL located within the cortical or medullary regions. Spectral peaks were assigned by the addition of known compounds to the perfusion medium and by comparison with spectra of protein-free extracts of cortex and medulla. The medullary region spectra were characterized by signals from the osmolytes betaine, Glycerophosphorylcholine, and inositol. The spectra from the cortex were more complex and contained lesser contributions from osmolytes.
Andrew N Lane - One of the best experts on this subject based on the ideXlab platform.
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identification of Glycerophosphorylcholine in mussel ovarian extracts by two dimensional nuclear magnetic resonance
Analytical Biochemistry, 1992Co-Authors: Teresa W M Fan, Andrew N LaneAbstract:The abundance of the "phosphodiester" peak in differentiating or proliferating tissues, including reproductive organs and tumors, warrants further investigations of its metabolic role(s), which would require a rigorous confirmation of its identity. The assignment of this peak to Glycerophosphorylcholine in 31P NMR spectra of biological samples has been largely based on chemical shift, which can result in ambiguities. We employed a combination of two-dimensional 31P-1H heteronuclear shift correlation and 1H total correlation spectroscopies to trace the spin connectivities of Glycerophosphorylcholine and thus to identify its structure directly from crude ovarian extracts of mussels without ambiguities and the need for extensive purification. This approach can be applied generally to the identification of molecules containing heteroatoms in crude tissue extracts.