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147 results on '"Elbayed, Karim"'

2. Metabolome Profiling by HRMAS NMR Spectroscopy of Pheochromocytomas and Paragangliomas Detects SDH Deficiency: Clinical and Pathophysiological Implications

Author

Imperiale, Alessio, Moussallieh, François-Marie, Roche, Philippe, Battini, Stéphanie, Cicek, A. Ercument, Sebag, Frédéric, Brunaud, Laurent, Barlier, Anne, Elbayed, Karim, Loundou, Anderson, Bachellier, Philippe, Goichot, Bernard, Stratakis, Constantine A., Pacak, Karel, Namer, Izzie-Jacques, and Taïeb, David

Published
2015
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11. Investigation of tetrahedral mixed-metal carbonyl clusters by two-dimensional (super 59)Co COSY and DQFCOSY NMR experiments

Author

Kempgens, Pierre, Elbayed, Karim, Raya, Jesus, Granger, Pierre, Rose, Jacky, and Braunstein, Pierre

Subjects
Carbonyl compounds -- Chemical properties, Clusters (Chemistry) -- Research, Nuclear magnetic resonance spectroscopy -- Usage, Chemistry
Abstract

Two-dimensional (2D) (Super 59)Co correlation spectroscopy (COSY)/Double-quantum-filtered (DQF)COSY experiments are reported for three tetrahedral mixed-metal clusters HFeCo3(CO)11L with L = PPh3, p(OMe)3, and PCy3 (Cy = cyclohexyl). The 2-D (Super 59)Co COSY and DQFCOSY NMR spectra of these clusters in solution prove the existence of a scalar coupling constant between the (super 59)Co nuclei.

Published
2006

13. Synthesis and In SituBehavior of 1,4- and 2,5-(13C) Isotopomers of p-Phenylenediamine in Reconstructed Human Epidermis Using High Resolution Magic Angle Spinning NMR

Author

Srour, Hassan, Gosset, Alexis, Moussallieh, François-Marie, Elbayed, Karim, Giménez-Arnau, Elena, and Lepoittevin, Jean-Pierre

Abstract

p-Phenylenediamine (PPD) has been classified as a strong skin allergen, but when it comes to toxicological concerns, benzoquinone diamine (BQDI), the primary oxidation derivative of PPD, is frequently considered and was shown to covalently bind nucleophilic residues on model peptides. However, tests in solution are far from providing a reliable model, as the cutaneous metabolism of PPD is not covered. We now report the synthesis of two 13C substituted isotopomers of PPD, 1,4-(13C)p-phenylenediamine 1and 2,5-(13C)p-phenylenediamine 2, and the investigation of their reactivity in reconstructed human epidermis (RHE) using the high resolution magic angle spinning (HRMAS) NMR technique. RHE samples were first treated with 1or 2and incubated for 1 to 48 h. Compared to the control, spectra clearly showed only the signals of 1or 2gradually decreasing with time to disappear after 48 h of incubation. However, the culture media of RHE incubated with 1for 1 and 24 h, respectively, showed the presence of both monoacetylated- and diacetylated-PPD as major products. Therefore, the acetylation reaction catalyzed by N-acetyltransferase (NAT) enzymes appeared to be the main process taking place in RHE. With the aim of increasing the reactivity by oxidation, 1and 2were treated with 0.5 equiv of H2O2prior to their application to RHE and incubated for different times. Under these conditions, new peaks having close chemical shifts to those of PPD-cysteine adducts previously observed in solution were detected. Under such oxidative conditions, we were thus able to detect and quantify cysteine adducts in RHE (maximum of 0.2 nmol/mg of RHE at 8 h of incubation) while no reaction with other nucleophilic amino acid residues could be observed.

Published
2022
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16. Evidence of secondary structure by high-resolution magic angle spinning NMR spectroscopy of a bioactive peptide bound to different solid supports

Author

Furrer, Julien, Piotto, Martial, Bourdonneau, Maryse, Limal, David, Guichard, Gilles, Elbayed, Karim, Raya, Jesus, Briand, Jean-Paul, and Bianco, Alberto

Subjects
Foot-and-mouth disease virus -- Research, Nuclear magnetic resonance spectroscopy -- Usage, Proteins -- Research, Chemistry
Abstract

Research is presented concerning the use of high-resolution magic angle spinning NMR spectroscopy to determine the structure of the 141-159 sequence of the foot-and-mouth disease virus capsid viral protein VP1.

Published
2001

21. Towards real-time metabolic profiling of a biopsy specimen during a surgical operation by 1H high resolution magic angle spinning nuclear magnetic resonance: a case report

Author

Piotto Martial, Moussallieh François-Marie, Neuville Agnès, Bellocq Jean-Pierre, Elbayed Karim, and Namer Izzie

Subjects
Medicine
Abstract

Abstract Introduction Providing information on cancerous tissue samples during a surgical operation can help surgeons delineate the limits of a tumoral invasion more reliably. Here, we describe the use of metabolic profiling of a colon biopsy specimen by high resolution magic angle spinning nuclear magnetic resonance spectroscopy to evaluate tumoral invasion during a simulated surgical operation. Case presentation Biopsy specimens (n = 9) originating from the excised right colon of a 66-year-old Caucasian women with an adenocarcinoma were automatically analyzed using a previously built statistical model. Conclusions Metabolic profiling results were in full agreement with those of a histopathological analysis. The time-response of the technique is sufficiently fast for it to be used effectively during a real operation (17 min/sample). Metabolic profiling has the potential to become a method to rapidly characterize cancerous biopsies in the operation theater.

Published
2012
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26. Modifications induced by chemical skin allergens on the metabolome of reconstructed human epidermis: A pilot high‐resolution magic angle spinning nuclear magnetic resonance study.

Author

Moussallieh, François‐Marie, Moss, Eric, Elbayed, Karim, Lereaux, Guillaume, Tourneix, Fleur, and Lepoittevin, Jean‐Pierre

Subjects
MAGIC angle spinning, NUCLEAR magnetic resonance, EPIDERMIS, ALLERGENS, EXTRACTION techniques
Abstract

Background: High‐resolution magic angle spinning (HRMAS) is a nuclear magnetic resonance (NMR) technique that enables the characterization of metabolic phenotypes/metabolite profiles of cells, tissues, and organs, under both normal and pathological conditions, without resorting to time‐consuming extraction techniques. Objectives: To assess the impact of chemical skin sensitizers vs non‐sensitizers on the metabolome of three‐dimensional reconstructed human epidermis (RHE) by HRMAS NMR. Methods: Based on the SENS‐IS assay, 12 skin sensitizers and five non‐sensitizing chemicals were investigated and applied on EpiSkin RHE at the published maximal non‐irritating concentrations under the conditions of the test. The metabolome of RHE samples was then analyzed by HRMAS NMR. Results: A total of 32 different metabolites were identified; 20 of these were quantified for all samples. Statistical univariate analysis showed that the tissue content of most measured metabolites (with the exception of acetate and glucose) was different in the untreated, treated with non‐sensitizers, and treated with sensitizers samples. In RHE samples in contact with sensitizing chemicals, concentrations of 18 metabolites were significantly decreased. Alanine and tyrosine could not discriminate between sensitizer‐ and non‐sensitizer‐treated groups. A multivariate partial least‐squares‐discriminant analysis was performed on the two treated groups, discriminating sensitizing and non‐sensitizing chemicals with a very good R2Y value of 0.87 and a good Q2Y value of 0.70. Conclusions: Data suggest that HRMAS NMR could be used to monitor the impact of chemicals, skin allergens vs non‐sensitizers, on the metabolome of three‐dimensional RHE. Highlights: A total of 32 different metabolites were identified in reconstructed human epidermis (RHE) by high‐resolution magic angle spinning nuclear magnetic resonance, among which 20 could be quantified for all samples.Statistical univariate analysis showed that the measured metabolites were different in the RHE samples treated with sensitizers vs non‐sensitizers.A multivariate partial least‐squares‐discriminant analysis was performed on the two treated groups, discriminating sensitizing and non‐sensitizing chemicals. [ABSTRACT FROM AUTHOR]

Published
2020
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28. A Metabolomic Approach (1H HRMAS NMR Spectroscopy) Supported by Histology to Study Early Post-transplantation Responses in Islet-transplanted Livers

Author

Vivot, Kevin, primary, Benahmed, Malika A., additional, Seyfritz, Elodie, additional, Bietiger, William, additional, Elbayed, Karim, additional, Ruhland, Elisa, additional, Langlois, Allan, additional, Maillard, Elisa, additional, Pinget, Michel, additional, Jeandidier, Nathalie, additional, Gies, Jean-Pierre, additional, Namer, Izzie-Jacques, additional, Sigrist, Séverine, additional, and Reix, Nathalie, additional

Published
2016
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34. Metabolic Characterization of Caviar Specimens by H NMR Spectroscopy: Towards Caviar Authenticity and Integrity.

Author

Heude, Clement, Elbayed, Karim, Jezequel, Tangi, Fanuel, Mathieu, Lugan, Raphael, Heintz, Dimitri, Benoit, Philippe, and Piotto, Martial

Abstract

The specific metabolic profile of aqueous extracts of caviar samples ( n = 91) originating from producers in the Aquitaine region in France was determined using H NMR spectroscopy. This metabolic profile was used to develop multivariate statistical models (Soft Independent Modeling by Class Analogy (SIMCA) and Orthogonal Partial Least Square Discriminant Analysis (OPLS-DA)) for the purpose of differentiating the Aquitaine production from other productions. The main purpose of these models is to help Aquitaine producers establish a protected geographical indication (PGI) to protect their know-how in caviar production from aquaculture. The parameters characterizing both the OPLS-DA and the SIMCA models were quite satisfactory, and the analysis of blind test samples with the two models provided a good level of discrimination between Aquitaine caviars and other caviars. The same NMR metabolic profile could also be used to provide an estimation of the freshness of caviar samples and define a shelf life for caviar cans. The first characterization of the different metabolites detected in caviar specimens by H NMR spectroscopy is also presented. The statistical models obtained could be used to prevent counterfeiting of Aquitaine caviar and guarantee an adequate level of freshness. [ABSTRACT FROM AUTHOR]

Published
2016
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35. The assessment of the quality of the graft in an animal model for lung transplantation using the metabolomics 1 H high-resolution magic angle spinning NMR spectroscopy

Author

Benahmed, Malika A., primary, Santelmo, Nicola, additional, Elbayed, Karim, additional, Frossard, Nelly, additional, Noll, Eric, additional, Canuet, Mathieu, additional, Pottecher, Julien, additional, Diemunsch, Pierre, additional, Piotto, Martial, additional, Massard, Gilbert, additional, and Namer, Izzie J., additional

Published
2011
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40. Analysis and exploitation of nuclear magnetic relaxation measurements : thorough study of cross-relaxation phenomena in txo spin 1/2 system

Author

Elbayed, Karim, Université Henri Poincaré - Nancy 1 (UHP), Université Henri Poincaré - Nancy 1, Daniel Canet, and UL, Thèses

Subjects
Systèmes de deux spins 1/2, [PHYS.COND.CM-GEN] Physics [physics]/Condensed Matter [cond-mat]/Other [cond-mat.other], [PHYS.COND.CM-GEN]Physics [physics]/Condensed Matter [cond-mat]/Other [cond-mat.other], Octyl-benzène sulfonate du sodium(obs), Relaxation croisée, Termes d'interférence, Relaxation spin-spin, Tensio-actifs micellisés, Transferts de type hartmann-hahn, 4-dodecyl-benzène sulfonate du sodium(4-DBS), Paramètres dynamiques et mouvements moléculaires
Abstract

Not available, Ce travail a été entrepris en vue d'une étude approfondie des phénomènes de relaxation croisée dans un système de deux spins 1/2. Nous avons été amenés à développer des logiciels qui couvrent toutes les phases du traitement de données de RMN : analyse des signaux de précession libre (RMNY), traitement des données de relaxation (TFIT) en termes de paramètres dynamiques et interprétation de ces derniers en termes de mouvements moléculaires (TWOSTEG). Ces logiciels sont écrits en turbo pascal et fonctionnent sur tout micro-ordinateur compatible PC. L'étude de la relaxation croisée a été réalisée sur deux tensio-actifs micellisés comportant un cycle benzénique avec la tête polaire et la chaîne aliphatique en position para. Ce sont l'obs (octyl-benzène sulfonate du sodium) et le 4-DBS (4-dodecyl-benzène sulfonate du sodium) étudiés dans les mêmes conditions (0.3M dans D20 à 50#O). Nous avons élaboré de nouvelles méthodes aussi bien sur le plan expérimental que sur le plan du traitement pour : 1) Détermination précise des termes de relaxation croisée, en fonction de la fréquence de mesure, dans des systèmes homo et hétéronucléaires de deux spins 1/2 ; 2) détermination précise des termes d'interférence entre l'intéraction dipolaire carbone-proton et l'anisotropie de déplacement chimique du carbone ou du proton ; 3) Étude d'un système de deux spins 1/2 couplés en présence d'un champ radio-fréquence (relaxation et transferts de type hartmann-hahn)

Published
1990

41. Logiciels pour l'analyse et l'exploitation des mesures de relaxation magnétique nucléaire : étude approfondie des phénomènes de relaxation croisée dans un système de deux spin 1/2

Author

Elbayed, Karim, UL, Thèses, Université Henri Poincaré - Nancy 1 (UHP), Université Henri Poincaré - Nancy 1, and Daniel Canet

Subjects
Systèmes de deux spins 1/2, [PHYS.COND.CM-GEN] Physics [physics]/Condensed Matter [cond-mat]/Other [cond-mat.other], [PHYS.COND.CM-GEN]Physics [physics]/Condensed Matter [cond-mat]/Other [cond-mat.other], Octyl-benzène sulfonate du sodium(obs), Relaxation croisée, Termes d'interférence, Relaxation spin-spin, Tensio-actifs micellisés, Transferts de type hartmann-hahn, 4-dodecyl-benzène sulfonate du sodium(4-DBS), Paramètres dynamiques et mouvements moléculaires
Abstract

Not available, Ce travail a été entrepris en vue d'une étude approfondie des phénomènes de relaxation croisée dans un système de deux spins 1/2. Nous avons été amenés à développer des logiciels qui couvrent toutes les phases du traitement de données de RMN : analyse des signaux de précession libre (RMNY), traitement des données de relaxation (TFIT) en termes de paramètres dynamiques et interprétation de ces derniers en termes de mouvements moléculaires (TWOSTEG). Ces logiciels sont écrits en turbo pascal et fonctionnent sur tout micro-ordinateur compatible PC. L'étude de la relaxation croisée a été réalisée sur deux tensio-actifs micellisés comportant un cycle benzénique avec la tête polaire et la chaîne aliphatique en position para. Ce sont l'obs (octyl-benzène sulfonate du sodium) et le 4-DBS (4-dodecyl-benzène sulfonate du sodium) étudiés dans les mêmes conditions (0.3M dans D20 à 50#O). Nous avons élaboré de nouvelles méthodes aussi bien sur le plan expérimental que sur le plan du traitement pour : 1) Détermination précise des termes de relaxation croisée, en fonction de la fréquence de mesure, dans des systèmes homo et hétéronucléaires de deux spins 1/2 ; 2) détermination précise des termes d'interférence entre l'intéraction dipolaire carbone-proton et l'anisotropie de déplacement chimique du carbone ou du proton ; 3) Étude d'un système de deux spins 1/2 couplés en présence d'un champ radio-fréquence (relaxation et transferts de type hartmann-hahn)

Published
1990

44. Conformational analysis by HRMAS NMR spectroscopy of resin-bound homo-peptides from Cα-methyl-leucine

Author

Rainaldi, Mario, primary, Lancelot, Nathalie, additional, Elbayed, Karim, additional, Raya, Jesus, additional, Piotto, Martial, additional, Briand, Jean-Paul, additional, Kaptein, Bernard, additional, Broxterman, Quirinus B., additional, Berkessel, Albrecht, additional, Formaggio, Fernando, additional, Toniolo, Claudio, additional, and Bianco, Alberto, additional

Published
2003
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