126 results match your criteria: "laboratoire associé à l'Université Pierre et Marie Curie[Affiliation]"

Objective: This study aimed to assess if quantitative diffusion magnetic resonance imaging analysis would improve prognostication of individual patients with severe traumatic brain injury.

Methods: We analyzed images of 30 healthy controls to extract normal fractional anisotropy ranges along 18 white-matter tracts. Then, we analyzed images of 33 patients, compared their fractional anisotropy values with normal ranges extracted from controls, and computed severity of injury to white-matter tracts.

View Article and Find Full Text PDF

There is experimental evidence that the astaxanthin, betanin, and epigallocatechin-3-gallate (EGCG) compounds slow down the aggregation kinetics and the toxicity of the amyloid-β (Aβ) peptide. How these inhibitors affect the self-assembly at the atomic level remains elusive. To address this issue, we have performed for each ligand atomistic replica exchange molecular dynamic (REMD) simulations in an explicit solvent of the Aβ trimer from the U-shape conformation and MD simulations starting from Aβ dimer and tetramer structures characterized by different intra- and interpeptide conformations.

View Article and Find Full Text PDF

Background: Fabry disease (OMIM 301500) is an X-linked disorder caused by alpha-galactosidase A (α-Gal A) deficiency. The administration of a pharmacologic chaperone (migalastat) in Fabry patients with amenable mutations has been reported to improve or stabilize organ damages and reduce lyso-Gb3 plasma level. An increase of α-Gal A activity has been observed in vitro in cells expressing amenable GLA mutations when incubated with migalastat.

View Article and Find Full Text PDF

Global impact models represent process-level understanding of how natural and human systems may be affected by climate change. Their projections are used in integrated assessments of climate change. Here we test, for the first time, systematically across many important systems, how well such impact models capture the impacts of extreme climate conditions.

View Article and Find Full Text PDF

Dihydroorotase (DHOase) is involved in the de novo synthesis of pyrimidine in virtually all organisms, and it is usually associated with two other enzymes found in this biosynthetic pathway, carbamylphosphate synthetase and/or aspartate transcarbamylase (ATCase). In the hyperthermophilic bacterium Aquifex aeolicus, ATCase and DHOase are noncovalently associated. Upon dissociation, ATCase keeps its activity entirely while DHOase is totally inactivated.

View Article and Find Full Text PDF

Atmospheric deposition, CO, and change in the land carbon sink.

Sci Rep

August 2017

CSIC, Global Ecology Unit, CREAF-CSIC-UAB, Cerdanyola del Vallès, 08193, Barcelona, Catalonia, Spain.

Concentrations of atmospheric carbon dioxide (CO) have continued to increase whereas atmospheric deposition of sulphur and nitrogen has declined in Europe and the USA during recent decades. Using time series of flux observations from 23 forests distributed throughout Europe and the USA, and generalised mixed models, we found that forest-level net ecosystem production and gross primary production have increased by 1% annually from 1995 to 2011. Statistical models indicated that increasing atmospheric CO was the most important factor driving the increasing strength of carbon sinks in these forests.

View Article and Find Full Text PDF

Enzyme Activation with a Synthetic Catalytic Co-enzyme Intermediate: Nucleotide Methylation by Flavoenzymes.

Angew Chem Int Ed Engl

October 2017

Laboratoire de Chimie des Processus Biologiques, CNRS-UMR 8229, Collège De France, Université Pierre et Marie Curie, 11 place Marcelin Berthelot, 75231, Paris Cedex 05, France.

To facilitate production of functional enzymes and to study their mechanisms, especially in the complex cases of coenzyme-dependent systems, activation of an inactive apoenzyme preparation with a catalytically competent coenzyme intermediate is an attractive strategy. This is illustrated with the simple chemical synthesis of a flavin-methylene iminium compound previously proposed as a key intermediate in the catalytic cycle of several important flavoenzymes involved in nucleic acid metabolism. Reconstitution of both flavin-dependent RNA methyltransferase and thymidylate synthase apoproteins with this synthetic compound led to active enzymes for the C5-uracil methylation within their respective transfer RNA and dUMP substrate.

View Article and Find Full Text PDF

High-Resolution Structures of the Amyloid-β 1-42 Dimers from the Comparison of Four Atomistic Force Fields.

J Phys Chem B

June 2017

Laboratoire de Biochimie Théorique, UPR 9080 CNRS, Université Paris Diderot, Sorbonne Paris Cité, IBPC, 13 Rue Pierre et Marie Curie, 75005 Paris, France.

The dimer of the amyloid-β peptide Aβ of 42 residues is the smallest toxic species in Alzheimer's disease, but its equilibrium structures are unknown. Here we determined the equilibrium ensembles generated by the four atomistic OPLS-AA, CHARMM22*, AMBER99sb-ildn, and AMBERsb14 force fields with the TIP3P water model. On the basis of 144 μs replica exchange molecular dynamics simulations (with 750 ns per replica), we find that the four force fields lead to random coil ensembles with calculated cross-collision sections, hydrodynamics properties, and small-angle X-ray scattering profiles independent of the force field.

View Article and Find Full Text PDF

Acute Facial Nerve Palsy With Ipsilateral Soft Palate Ulcers.

J Oral Maxillofac Surg

September 2017

Associate Professor, AP-HP, Service de chirurgie maxillo-faciale, Hôpital Universitaire Pitié-Salpêtrière, Paris; Université Pierre-et-Marie-Curie, Paris, France. Electronic address:

Ramsay-Hunt syndrome (RHS) is a rare complication of herpes zoster in which reactivation of latent varicella zoster virus (VZV) infection occurs in the geniculate ganglion. Major clinical findings are peripheral facial nerve palsy accompanied by ipsilateral ear pain and erythematous vesicular rash on the external ear (herpes zoster oticus) and in the mouth. Thus, diagnosis of RHS is usually clinical.

View Article and Find Full Text PDF

Evolution of ligands, receptors and metabolizing enzymes of thyroid signaling.

Mol Cell Endocrinol

December 2017

Laboratoire de Biologie Intégrative des Organismes Marins UMR 7232, CNRS et Université Pierre et Marie Curie, Avenue Pierre Fabre, 66650 Banyuls-sur-Mer, France. Electronic address:

Thyroid hormones (THs) play important roles in vertebrates such as the control of the metabolism, development and seasonality. Given the pleiotropic effects of thyroid disorders (developmental delay, mood disorder, tachycardia, etc), THs signaling is highly investigated, specially using mammalian models. In addition, the critical role of TH in controlling frog metamorphosis has led to the use of Xenopus as another prominent model to study THs action.

View Article and Find Full Text PDF

Aryl Butenes Active against K562 Cells and Lacking Tyrosinase Inhibitory Activity as New Leads in the Treatment of Leukemia.

Mini Rev Med Chem

September 2018

Universite Pierre et Marie Curie-Paris, Sorbonne Universites, Institut Parisien de Chimie Moleculaire (IPCM) - UMR 8232, 4 place Jussieu, 75252 Paris Cedex 05, France.

Background & Objective: The inhibitory effects of four series of aryl butene derivatives, active against breast cancer, on the monophenolase activity of tyrosinase, in melanin-free ink from Sepia officinalis, have been studied. Hydroxytamoxifen 1, ferrociphenol 17 and several aryl butene analogs have shown strong antiproliferative activity on hormone-dependent and hormone-independent breast cancer cells and were evaluated in leukemia K562 cell proliferation. Their potential to induce skin depigmentation by evaluating their anti-tyrosinase activity was also estimated.

View Article and Find Full Text PDF

Metabolic Control of Tobacco Pollination by Sugars and Invertases.

Plant Physiol

February 2017

Institut für Zellbiologie und Pflanzenphysiologie, Universität Regensburg, 93053 Regensburg, Germany (M.G., T.R.);

Pollination in flowering plants is initiated by germination of pollen grains on stigmas followed by fast growth of pollen tubes representing highly energy-consuming processes. The symplastic isolation of pollen grains and tubes requires import of Suc available in the apoplast. We show that the functional coupling of Suc cleavage by invertases and uptake of the released hexoses by monosaccharide transporters are critical for pollination in tobacco (Nicotiana tabacum).

View Article and Find Full Text PDF

Electrophilic RNA for Peptidyl-RNA Synthesis and Site-Specific Cross-Linking with tRNA-Binding Enzymes.

Angew Chem Int Ed Engl

October 2016

Laboratoire de Chimie et de Biochimie Pharmacologiques et Toxicologiques, Université Paris Descartes, UMR 8601, Paris, F-75006, France.

RNA functionalization is challenging due to the instability of RNA and the limited range of available enzymatic reactions. We developed a strategy based on solid phase synthesis and post-functionalization to introduce an electrophilic site at the 3' end of tRNA analogues. The squarate diester used as an electrophile enabled sequential amidation and provided asymmetric squaramides with high selectivity.

View Article and Find Full Text PDF

Monitoring of freshwater toxins in European environmental waters by using novel multi-detection methods.

Environ Toxicol Chem

March 2017

Department of Pharmacology, Faculty of Veterinary, Universidade de Santiago de Compostela, Lugo, Spain.

Monitoring the quality of freshwater is an important issue for public health. In the context of the European project μAqua, 150 samples were collected from several waters in France, Germany, Ireland, Italy, and Turkey for 2 yr. These samples were analyzed using 2 multitoxin detection methods previously developed: a microsphere-based method coupled to flow-cytometry, and an ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) method.

View Article and Find Full Text PDF

Modelling survival: exposure pattern, species sensitivity and uncertainty.

Sci Rep

July 2016

Bayer CropScience Aktiengesellschaft, BCS AG-R&D-D-EnSa-Emod, Monheim, Germany.

The General Unified Threshold model for Survival (GUTS) integrates previously published toxicokinetic-toxicodynamic models and estimates survival with explicitly defined assumptions. Importantly, GUTS accounts for time-variable exposure to the stressor. We performed three studies to test the ability of GUTS to predict survival of aquatic organisms across different pesticide exposure patterns, time scales and species.

View Article and Find Full Text PDF

Association of hidradenitis suppurativa and familial Mediterranean fever: A case series of 6 patients.

Joint Bone Spine

March 2017

Service de médecine interne, centre de référence des amyloses d'origine inflammatoire et de la fièvre méditerranéenne familiale, hôpital Tenon, Assistance publique-Hôpitaux de Paris (AP-HP), université Paris 6, Pierre-et-Marie-Curie (UPMC), 20, rue de la Chine, 75020 Paris, France; Inserm UMRS_933, hôpital Trousseau, AP-HP université Pierre-et Marie-Curie (UPMC)-Paris 6, Paris, France.

Objectives: Familial mediterranean fever (FMF) is the most common monogenic autoinflammatory disease. Hidradenitis suppurativa (HS) is an inflammatory cutaneous disease. Those diseases can occur simultaneously among the same individual.

View Article and Find Full Text PDF

The electrochemical response of many redox species on boron-doped diamond (BDD) electrodes can be strongly dependent on the type of chemical termination on their surface, hydrogen (HT-BDD) or oxygen (OT-BDD). For instance, on an HT-BDD electrode the [Fe(CN)6](3-/4-) redox system presents a reversible voltammetric behavior, whereas the oxidation overpotential of ascorbic acid (AA) is significantly decreased. Moreover, the electrochemical activity of BDD electrodes can be significantly affected by electrochemical pretreatments, with cathodic pretreatments (CPTs) leading to redox behaviors associated with HT-BDD.

View Article and Find Full Text PDF

Biocompatible amphiphilic block copolymers composed of polysarcosine (PSar) and poly(ε-caprolactone) (PCL) were synthesized using ring-opening polymerization of sarcosine N-thiocarboxyanhydride initiated by oxyamine-ended PCL and characterized by NMR, SEC, and DSC. Self-assembling of two triblock copolymers PSar8-b-PCL28-b-PSar8 (CS7) and PSar16-b-PCL40-b-PSar16 (CS10) in dilute solution was studied in detail toward polymersome formation using thin-film hydration and nanoprecipitation techniques. A few giant vesicles were obtained by thin-film hydration from both copolymers and visualized by confocal laser scanning microscope.

View Article and Find Full Text PDF

Release kinetics of an amphiphilic photosensitizer by block-polymer nanoparticles.

Int J Pharm

November 2015

Université Pierre et Marie Curie-Paris 6, Laboratoire Jean Perrin - UMR8237, 4 place Jussieu, Paris F-75005, France; CNRS, Laboratoire Jean Perrin, UMR8237, 4 place Jussieu, Paris F-75005, France. Electronic address:

Block-polymer nanoparticles are now well-known candidates for the delivery of various non-soluble drugs to cells. The release of drugs from these nanoparticles is a major concern related to their efficiency as nanovectors and is still not completely deciphered. Various processes have been identified, depending of both the nature of the block-polymer and those of the drugs used.

View Article and Find Full Text PDF

Inhibition of the aggregation of the monomeric peptide β-amyloid (Aβ) into oligomers is a widely studied therapeutic approach in Alzheimer's disease (AD). Many small molecules have been reported to work in this way, including 1,4-naphthoquinon-2-yl-L-tryptophan (NQ-Trp). NQ-Trp has been reported to inhibit aggregation, to rescue cells from Aβ toxicity, and showed complete phenotypic recovery in an in vivo AD model.

View Article and Find Full Text PDF

From Homogeneous to Segregated Structure of Poly(dimethylsiloxane)/Cellulose Derivative Mixed Langmuir Films Depending on Composition: An in Situ Neutron Reflectivity Study.

Langmuir

June 2015

†Laboratoire de Physicochimie des Polymères et des Interfaces (LPPI, EA 2528), Institut des Matériaux, Université de Cergy-Pontoise, 5 mail Gay-Lussac Neuville/Oise, Cergy-Pontoise Cedex 95000, France.

The mixing behavior of deuterated polydimethylsiloxane (PDMSd) and cellulose acetate butyrate (CAB) spread as Langmuir films at the air-water interface was studied by means of surface pressure-area isotherms, Brewster angle microscopy (BAM) observations, and in situ neutron reflectivity. The contrast variation method was used with different D2O/H2O mixtures as subphase, allowing contrast matching to either CAB, PDMSd, or PDMSd/CAB mixed film if homogeneous. At PDMSd volume fractions Φ lower than 0.

View Article and Find Full Text PDF

Demethylmenaquinol is a substrate of Escherichia coli nitrate reductase A (NarGHI) and forms a stable semiquinone intermediate at the NarGHI quinol oxidation site.

Biochim Biophys Acta

August 2015

Aix-Marseille Université, CNRS, Unité de Bioénergétique et Ingénierie des Protéines (UMR7281), F-13402 Marseille, France. Electronic address:

Quinones are essential building blocks of respiration, a universal process dedicated to efficient harvesting of environmental energy and its conversion into a transmembrane chemiosmotic potential. Quinones differentiate mostly by their midpoint redox potential. As such, γ-proteobacteria such as Escherichia coli are characterized by the presence of demethylmenaquinone (DMK) with an intermediate redox potential between low-potential (menaquinone) and high-potential (ubiquinone) quinones.

View Article and Find Full Text PDF

Ferrociphenols have been found to have high antiproliferative activity against estrogen-independent breast cancer cells. The rat and human liver microsome-mediated metabolism of three compounds of the ferrocifen (FC) family, 1,1-bis(4-hydroxyphenyl)-2-ferrocenyl-but-1-ene (FC1), 1-(4-hydroxyphenyl)-1-(phenyl)-2-ferrocenyl-but-1-ene (FC2), and 1-[4-(3-dimethylaminopropoxy)phenyl]-1-(4-hydroxyphenyl)-2-ferrocenyl-but-1-ene (FC3), was studied. Three main metabolite classes were identified: quinone methides (QMs) deriving from two-electron oxidation of FCs, cyclic indene products (CPs) deriving from acid-catalyzed cyclization of QMs, and allylic alcohols (AAs) deriving from hydroxylation of FCs.

View Article and Find Full Text PDF