Tandem mass spectrometric analysis of a mixture of isobars using the survival yield technique.

International audienceCollision induced dissociation tandem mass spectrometry experiments were performed to unequivocally separate compounds from an isobaric mixture of two products. The Survival Yield curve was obtained and is shown to consist in a linear combination of the curves corresponding to the two components separately. For such a mixture, a plateau appears on the diagram in lieu of the continuous decrease expected allowing for the structural study of the two components separately. The width of the plateau critically relates to the fragmentation parameters of the two molecular ions, which need to be sufficiently different structurally for the plateau to be observed. However, at constant fragmentation parameters, we have observed the width significantly increases at large m/z. This makes the separation more and more efficient as isobars have larger m/z and the technique complementary to those applicable at low m/z only. We have observed that the vertical position of the plateau relates linearly to the relative concentration of the two compounds that may be useful for quantification. Repeatability was estimated at 2% on a quadrupole ion trap. An advantage of using survival yield curves only, is that a priori knowledge of the respective fragmentation patterns of the two isobars becomes unnecessary. Consequently, similar performances are obtained if fragments are isobaric, which is also demonstrated in our study. The critical case of reverse peptides, at low m/z and similar fragmentation parameters, is also presented as a limitation of the method

Simple scoring system to predict in-hospital mortality after surgery for infective endocarditis

BACKGROUND: Aspecific scoring systems are used to predict the risk of death postsurgery in patients with infective endocarditis (IE). The purpose of the present study was both to analyze the risk factors for in-hospital death, which complicates surgery for IE, and to create a mortality risk score based on the results of this analysis. METHODS AND RESULTS: Outcomes of 361 consecutive patients (mean age, 59.1\ub115.4 years) who had undergone surgery for IE in 8 European centers of cardiac surgery were recorded prospectively, and a risk factor analysis (multivariable logistic regression) for in-hospital death was performed. The discriminatory power of a new predictive scoring system was assessed with the receiver operating characteristic curve analysis. Score validation procedures were carried out. Fifty-six (15.5%) patients died postsurgery. BMI >27 kg/m2 (odds ratio [OR], 1.79; P=0.049), estimated glomerular filtration rate 55 mm Hg (OR, 1.78; P=0.032), and critical state (OR, 2.37; P=0.017) were independent predictors of in-hospital death. A scoring system was devised to predict in-hospital death postsurgery for IE (area under the receiver operating characteristic curve, 0.780; 95% CI, 0.734-0.822). The score performed better than 5 of 6 scoring systems for in-hospital death after cardiac surgery that were considered. CONCLUSIONS: A simple scoring system based on risk factors for in-hospital death was specifically created to predict mortality risk postsurgery in patients with IE

Mise au point du dosage de métabolites de toxiques de guerre organophosphorés

Dans un contexte international tendu, les attentats au gaz sarin dans les années 1990 ont démontré la possibilité d un emploi terroriste des agents neurotoxiques organophosphorés (NOPs) comme arme chimique. Le développement de méthodes de dosage des traces de NOPs et de leurs métabolites dans les milieux biologiques est donc indispensable pour la prise en charge et la protection des populations civiles et militaires. Ce travail est consacré à la mise au point du dosage de l acide pinacolylméthylphosphonique (PMPA), métabolite spécifique du gaz soman, dans un milieu biologique de synthèse (HBSS), par chromatographie gazeuse couplée à un détecteur azote-phosphore, précédée d une extraction solide-liquide (R = 88%) et d une dérivation au PFBBr (R = 47%). Cette méthode est linéaire (R2 > 0,99) entre 12,7 et 1270 nmol/L et présente des limites de détection et de quantification respectivement de 0,7 ng/mL et 2,5 ng/mL. Cette méthode de dosage pourra être étendue au dosage du PMPA dans l urine, après transposition de l extraction. Dans une première approche, le dosage par cette méthode de l acide éthylméthylphosphonique (métabolite du VX) et de l acide méthylphosphonique (métabolite terminal de nombreux NOPs) avait été envisagé ; pour différentes raisons, ce dosage a été momentanément abandonné. Cependant, cette partie pourra être réalisée ultérieurement lors du passage à une détection par spectrométrie de masse.LIMOGES-BU Médecine pharmacie (870852108) / SudocLYON1-BU Santé (693882101) / SudocSudocFranceF

Parade's End de Ford Madox Ford (vers une esthétique de la crise)

PARIS7-Bibliothèque centrale (751132105) / SudocSudocFranceF

Analyse toxicologique des composés organophosphores (application au diisopropylfluorophosphate, simili du sarin et du soman)

LYON1-BU Santé (693882101) / SudocSudocFranceF

Improved access to 2-O-monobenzyl ethers of β-cyclodextrin as precursors of catalysts for organophosphoryl esters hydrolysis

International audienc

La démarche qualité d'une plate-forme technologique - Guide pratique de mise en place

National audienc

Synthesis of 2-substituted β-cyclodextrin derivatives with a hydrolytic activity against the organophosphorylester paraoxon

International audienceβ-Cyclodextrin was substituted by an iodosobenzoic acid derivative to create a catalytic hydrolytic activity against neurotoxic organophosphorus agents. The catalytic moiety was introduced on a secondary hydroxy group at the position 2 of a glucose unit. Several β-cyclodextrin derivatives were obtained. In these derivatives, the methylene linker occupied all potential positions on the aromatic ring. Kinetic assays were carried out with paraoxon as organophosphate model. Three regioisomers hydrolyzed paraoxon, although the paraoxon-leaving group, para-nitrophenol, was not released from the β-cyclodextrin torus

A fluorescence-quenched chitopentaose for the study of endo-chitinases and chitobiosidases

International audienc

State of Britain

Les articles réunis dans le présent volume ont été originellement présentés sous forme de communications dans le cadre du colloque de la SÉAC organisé en octobre 2014 à l’Université Paris-Diderot, Paris, en octobre 2015. Figure également au sommaire la retranscription de la table ronde sur laquelle s’est conclu le colloque. The articles collected in this volume developed from oral presentations originally delivered during the SEAC conference hosted the University Denis-Diderot, Paris and convened by Catherine Bernard in October 2014. The conference was rounded off by a round table on contemporary British fiction whose written version also features in this volume