Hyperpolarized 13C-glucose magnetic resonance highlights reduced aerobic glycolysis in vivo in infiltrative glioblastoma.

Glioblastoma (GBM) is the most aggressive brain tumor type in adults. GBM is heterogeneous, with a compact core lesion surrounded by an invasive tumor front. This front is highly relevant for tumor recurrence but is generally non-detectable using standard imaging techniques. Recent studies demonstrated distinct metabolic profiles of the invasive phenotype in GBM. Magnetic resonance (MR) of hyperpolarized 13C-labeled probes is a rapidly advancing field that provides real-time metabolic information. Here, we applied hyperpolarized 13C-glucose MR to mouse GBM models. Compared to controls, the amount of lactate produced from hyperpolarized glucose was higher in the compact GBM model, consistent with the accepted "Warburg effect". However, the opposite response was observed in models reflecting the invasive zone, with less lactate produced than in controls, implying a reduction in aerobic glycolysis. These striking differences could be used to map the metabolic heterogeneity in GBM and to visualize the infiltrative front of GBM

Hyperpolarized ¹³C Magnetic Resonance Spectroscopy Reveals the Rate-Limiting Role of the Blood-Brain Barrier in the Cerebral Uptake and Metabolism of l-Lactate in Vivo.

The dynamics of l-lactate transport across the blood-brain barrier (BBB) and its cerebral metabolism are still subject to debate. We studied lactate uptake and intracellular metabolism in the mouse brain using hyperpolarized <sup>13</sup> C magnetic resonance spectroscopy (MRS). Following the intravenous injection of hyperpolarized [1- <sup>13</sup> C]lactate, we observed that the distribution of the <sup>13</sup> C label between lactate and pyruvate, which has been shown to be representative of their pool size ratio, is different in NMRI and C57BL/6 mice, the latter exhibiting a higher level of cerebral lactate dehydrogenase A ( Ldha) expression. On the basis of this observation, and an additional set of experiments showing that the cerebral conversion of [1- <sup>13</sup> C]lactate to [1- <sup>13</sup> C]pyruvate increases after exposing the brain to ultrasound irradiation that reversibly opens the BBB, we concluded that lactate transport is rate-limited by the BBB, with a 30% increase in lactate uptake after its disruption. It was also deduced from these results that hyperpolarized <sup>13</sup> C MRS can be used to detect a variation in cerebral lactate uptake of <40 nmol in a healthy brain during an in vivo experiment lasting only 75 s, opening new opportunities to study the role of lactate in brain metabolism

Un terrain dans un salon

Bernard Comment se souvient, depuis le salon de coiffure de son enfance, des grandes heures de la Nati, l'équipe de Suisse de football, en Coupe du monde

Nadine Norman : Call Girl

This publication documents Norman’s installation at the Canadian Cultural Centre (Paris), in which the artist hired actresses to perform as Call Girls in the art gallery. Comment’s essay on the artist’s ten-week long performative installation focuses on the theme of seduction. He suggests Norman’s appropriation of phone sex is an intervention that critiques stereotypical representations of feminine sexuality/desire. Numerous references are made to the Homeric myth of Ulysses. Bédard’s interpretation of the piece centres on the significance of the exchange between Call Girl and viewer/participant. Includes a brief text by Giraudeau on Norman’s index.html installation (based on the myth of Penelope). Texts in French and English. Brief biographical notes on the artist and Comment. 4 bibl. ref

L'ongle noir / Comment ; postface de Bernard Wallet

Collection : Mille et une nuits ; 137Contient une table des matièresAvec mode text

Le paysage en éclats

A partir des ouvrages "La mission photographique de la DATAR" de Raphaële Bertho (Éd. La Documentation française, 2013) "France(s) territoire liquide" Ouvrage collectif, texte de Jean-Christophe Bailly (Éd. Seuil/Fiction & Cie, 2014) "Paysages superposés/Saclay panorama" de Antoine Vialle (Éd. Kaiserin, 2014) Quels regards porter sur la France du XXIe siècle ? Comment aborder ce territoire devenu multiple, plastique, « liquide » ? A travers les travaux de quarante-trois photographes et d’un architecte, le paysage s’esquisse ici dans l’assemblage de fragments, témoins d’une attention portée aux singularités. Ces éclats photographiques sont alors juxtaposés, “superposés”, pour dessiner peu à peu les contours de la complexité de notre modernité. En présence des auteurs. Cédric Delsaux, photographe Bernard Comment, Editeur Antoine Vialle, architecte, chercheur (EPFL / LAMU) Modératrice : Raphaële Bertho, maître de conférence