PPAR-mediated activity of phthalates: A link to the obesity epidemic?

The endocrine disruption hypothesis asserts that exposure to small amounts of some chemicals in the environment may interfere with the endocrine system and lead to harmful effects in wildlife and humans. Many of these chemicals may interact with members of the nuclear receptor superfamily. Peroxisome proliferator-activated receptors (PPARs) are such candidate members, which interact with many different endogenous and exogenous lipophilic compounds. More particularly, the roles of PPARs in lipid and carbohydrate metabolism raise the question of their activation by a sub-class of pollutants, tentatively named "metabolic disrupters". Phthalates are abundant environmental micro-pollutants in Europe and North America and may belong to this class. Mono-ethyl-hexyl-phthalate (MEHP), a metabolite of the widespread plasticizer di-ethyl-hexyl-phthalate (DEHP), has been found in exposed organisms and interacts with all three PPARs. A thorough analysis of its interactions with PPARgamma identified MEHP as a selective PPARgamma modulator, and thus a possible contributor to the obesity epidemic.

1/2/20, arrivée de [Denis dit] Bertrand, [coureur belge] gagnant du cross de l'Intransigeant [au Bois de Boulogne, pelouse de la Muette] : [photographie de presse] / [Agence Rol]

Référence bibliographique : Rol, 57832

Fracture imaging within a granitic rock aquifer using multiple-offset single-hole and cross-hole GPR reflection data

The sparsely spaced highly permeable fractures of the granitic rock aquifer at Stang-er-Brune (Brittany, France) form a well-connected fracture network of high permeability but unknown geometry. Previous work based on optical and acoustic logging together with single-hole and cross-hole flowmeter data acquired in 3 neighbouring boreholes (70-100 m deep) has identified the most important permeable fractures crossing the boreholes and their hydraulic connections. To constrain possible flow paths by estimating the geometries of known and previously unknown fractures, we have acquired, processed and interpreted multifold, single- and cross-hole GPR data using 100 and 250 MHz antennas. The GPR data processing scheme consisting of timezero corrections, scaling, bandpass filtering and F-X deconvolution, eigenvector filtering, muting, pre-stack Kirchhoff depth migration and stacking was used to differentiate fluid-filled fracture reflections from source generated noise. The final stacked and pre-stack depth-migrated GPR sections provide high-resolution images of individual fractures (dipping 30-90°) in the surroundings (2-20 m for the 100 MHz antennas; 2-12 m for the 250 MHz antennas) of each borehole in a 2D plane projection that are of superior quality to those obtained from single-offset sections. Most fractures previously identified from hydraulic testing can be correlated to reflections in the single-hole data. Several previously unknown major near vertical fractures have also been identified away from the boreholes.

21/2/20 [i.e. 22/2/20, Juvisy, championnat de Paris de cross country], Guillemot : [photographie de presse] / [Agence Rol]

Référence bibliographique : Rol, 58127

Clamart, 18-1-20, interclubs du comité de Paris, Denis gagnant [du cross-country] : [photographie de presse] / [Agence Rol]

Référence bibliographique : Rol, 57696

Mls: a link between immunology and retrovirology.

The nature of the mysterious minor lymphocyte stimulating (Mls) antigens has recently been clarified. These molecules which were key elements for our current understanding of immune tolerance, have a strong influence on the mouse immune system and are encoded by the open reading frame (orf) of endogenous and exogenous mouse mammary tumor viruses (MMTV's). The knowledge that these antigens are encoded by cancerogenic retroviruses opens an interdisciplinary approach for understanding the mechanisms of immune responses and immune tolerance, retroviral carcinogenesis, and retroviral strategies for infection.

1/2/20, [Denis dit] Bertrand, [coureur belge] gagnant du cross de l'Intransigeant [au Bois de Boulogne, pelouse de la Muette] : [photographie de presse] / [Agence Rol]

Référence bibliographique : Rol, 57839

1/2/20, [Denis dit] Bertrand, [coureur belge] gagnant du cross de l'Intransigeant [au Bois de Boulogne, pelouse de la Muette] : [photographie de presse] / [Agence Rol]

Référence bibliographique : Rol, 57837

1/2/20, départ du cross de l'Intransigeant [au Bois de Boulogne, pelouse de la Muette] : [photographie de presse] / [Agence Rol]

Référence bibliographique : Rol, 57831

1/2/20, départ du cross de l'Intransigeant [au Bois de Boulogne, pelouse de la Muette] : [photographie de presse] / [Agence Rol]

Référence bibliographique : Rol, 57830

An exquisite cross-control mechanism among endothelial cell fate regulators directs the plasticity and heterogeneity of lymphatic endothelial cells.

Arteriovenous-lymphatic endothelial cell fates are specified by the master regulators, namely, Notch, COUP-TFII, and Prox1. Whereas Notch is expressed in the arteries and COUP-TFII in the veins, the lymphatics express all 3 cell fate regulators. Previous studies show that lymphatic endothelial cell (LEC) fate is highly plastic and reversible, raising a new concept that all 3 endothelial cell fates may co-reside in LECs and a subtle alteration can result in a reprogramming of LEC fate. We provide a molecular basis verifying this concept by identifying a cross-control mechanism among these cell fate regulators. We found that Notch signal down-regulates Prox1 and COUP-TFII through Hey1 and Hey2 and that activated Notch receptor suppresses the lymphatic phenotypes and induces the arterial cell fate. On the contrary, Prox1 and COUP-TFII attenuate vascular endothelial growth factor signaling, known to induce Notch, by repressing vascular endothelial growth factor receptor-2 and neuropilin-1. We show that previously reported podoplanin-based LEC heterogeneity is associated with differential expression of Notch1 in human cutaneous lymphatics. We propose that the expression of the 3 cell fate regulators is controlled by an exquisite feedback mechanism working in LECs and that LEC fate is a consequence of the Prox1-directed lymphatic equilibrium among the cell fate regulators.

21/2/20 [i.e. 22/2/20], Juvisy, Guillemot vainqueur du championnat de Paris de cross country : [photographie de presse] / [Agence Rol]

Référence bibliographique : Rol, 58128