Syn-tectonic, meteoric water-derived carbonation of the New Caledonia peridotite nappe

International audienceExceptional outcrops recently exposed in the Koniambo massif allow the study of the serpentine sole of the peridotite nappe of New Caledonia (southwest Pacific Ocean). Many magnesite veins are observed, with characteristics indicating that they were emplaced during pervasive top-to-the-southwest shear deformation. The oxygen isotope composition of magnesite is homogeneous (27.4‰ < δ18O < 29.7‰), while its carbon isotope composition varies widely (−16.7‰ < δ13C < −8.5‰). These new data document an origin of magnesite from meteoric fluids. Laterization on top of the peridotite nappe and carbonation along the sole appear to represent complementary records of meteoric water infiltration. Based on the syn-kinematic character of magnesite veins, we propose that syn-laterization tectonic activity has enhanced water infiltration, favoring the exportation of leached elements like Mg, which has led to widespread carbonation along the serpentine sole. This calls for renewed examination of other magnesite-bearing ophiolites worldwide in order to establish whether active tectonics is commonly a major agent for carbonation

The metamorphic sole of New Caledonia ophiolite: 40Ar/39Ar, U-Pb, and geochemical evidence for subduction inception at a spreading ridge

Amphibolite lenses that locally crop out below the serpentinite sole at the base of the ophiolite of New Caledonia (termed Peridotite Nappe) recrystallized in the high-temperature amphibolite facies and thus sharply contrast with blueschists and eclogites of the Eocene metamorphic complex. Amphibolites mostly display the geochemical features of MORB with a slight Nb depletion and thus are similar to theyoungest (Late Paleocene–Eocene) BABB components of the allochthonous Poya Terrane. Thermochronological data from hornblende (40Ar/39Ar), zircon, and sphene (U-Pb) suggest that these mafic rocks recrystallized at ~56 Ma. Using various geothermobarometers provides a rough estimate of peak recrystallization conditions of ~0.5 GPa at ~80–95°C. The thermal gradient inferred from the metamorphic assemblage (~60°C km-1), geometrical relationships, and geochemical similarity suggest that these mafic rocks belong to the oceanic crust of the lower plate of the subduction/obduction system and recrystallized when they subducted below young and hot oceanic lithosphere. They were detached from the down-going plate and finally thrust onto unmetamorphosed Poya Terrane basalts. This and the occurrence of slab melts at ~53 Ma suggest that subduction inception occurred at or near to the spreading ridge of the South Loyalty Basin at ~56 Ma

European Organization for Research and Treatment of Cancer (EORTC) open label phase II study on glufosfamide administered as a 60-minute infusion every 3 weeks in recurrent glioblastoma multiforme

BACKGROUND: Glufosfamide is a new alkylating agent in which the active metabolite of isophosphoramide mustard is covalently linked to beta-D-glucose to target the glucose transporter system and increase intracellular uptake in tumor cells. We investigated this drug in a multicenter prospective phase II trial in recurrent glioblastoma multiforme (GBM). PATIENTS AND METHODS: Eligible patients had recurrent GBM following surgery, radiotherapy and no more than one prior line of chemotherapy. Patients were treated with glufosfamide 5000 mg/m(2) administered as a 1-h intravenous infusion. Treatment success was defined as patients with either an objective response according to Macdonald's criteria or 6 months progression-free survival. Toxicity was assessed with the Common Toxicity Criteria (CTC) version 2.0. RESULTS: Thirty-one eligible patients were included. Toxicity was modest, the main clinically relevant toxicities being leukopenia (CTC grade >3 in five patients) and hepatotoxicity (in three patients). No responses were observed; one patient (3%; 95% confidence interval 0 to 17%) was free from progression at 6 months. Pharmacokinetic analysis showed a 15% decrease in area under the curve and glufosfamide clearance in patients treated with enzyme-inducing antiepileptic drugs, but no effect of these drugs on maximum concentration and plasma half-life. CONCLUSION: Glufosfamide did not show significant clinical antitumor activity in patients with recurrent GBM

CC9 Livestock-Associated Staphylococcus aureus Emerges in Bloodstream Infections in French Patients Unconnected With Animal Farming

We report 4 bloodstream infections associated with CC9 agr type II Staphylococcus aureus in individuals without animal exposure. We demonstrate, by microarray analysis, the presence of egc cluster, fnbA, cap operon, lukS, set2, set12, splE, splD, sak, epiD, and can, genomic features associated with a high virulence potential in human

Rôle des peptides trifoliés et des mucines dans la régénération et la différenciation de l'épithélium respiratoire humain

REIMS-BU Santé (514542104) / SudocPARIS-BIUP (751062107) / SudocSudocFranceF

La femme alcoolo-dépendante et son médecin traitant (points de vue de patientes)

BREST-BU Médecine-Odontologie (290192102) / SudocPARIS-BIUM (751062103) / SudocSudocFranceF

Réparation et régénération de l’épithélium respiratoire

L’épithélium de surface des voies aériennes proximales assure la protection de la muqueuse respiratoire grâce à différents mécanismes, comme la clairance mucociliaire, la régulation des flux d’ions et d’eau et la sécrétion de molécules de défense. La seconde ligne de protection est assurée par des complexes jonctionnels intercellulaires permettant de préserver la fonction de barrière de l’épithélium. En contact permanent avec l’environnement extérieur, l’épithélium des voies aériennes est cependant fréquemment lésé par les agents toxiques, les bactéries ou les virus inhalés : ces lésions peuvent entraîner la perte de l’intégrité de la barrière épithéliale ou la desquamation partielle ou totale des cellules épithéliales. Afin de restaurer sa fonction, l’épithélium respiratoire doit non seulement réparer les lésions, mais aussi reconstituer et régénérer un épithélium fonctionnel. Ces processus complexes allient des fonctions de migration, prolifération et différenciation cellulaire, régulées par divers facteurs de croissance, cytokines, protéines de la matrice extracellulaire et enzymes protéolytiques. La connaissance des mécanismes cellulaires et moléculaires gouvernant la restauration tissulaire est un prérequis indispensable à l’élaboration de stratégies prorégénératrices de l’épithélium de surface des voies aériennes dans de nombreuses pathologies respiratoires telles que l’asthme, les bronchopneumopathies chroniques obstructives, la mucoviscidose ou les bronchiolites oblitérantes