Search results for "3a"
showing 10 items of 351 documents
Transcriptional Regulation of Human CYP3A4 Basal Expression by CCAAT Enhancer-Binding Protein α and Hepatocyte Nuclear Factor-3γ
2003
Cytochrome P450 3A4 (CYP3A4) is involved in the metabolism of more than 50% of currently used therapeutic drugs, yet the mechanisms that control CYP3A4 basal expression in liver are poorly understood. Several putative binding sites for CCAAT/enhancer-binding protein (C/EBP) and hepatic nuclear factor 3 (HNF-3) were found by computer analysis in CYP3A4 promoter. The use of reporter gene assays, electrophoretic mobility shift assays, and site-directed mutagenesis revealed that one proximal and two distal C/EBP alpha binding sites are essential sites for the trans-activation of CYP3A4 promoter. No trans-activation was found in similar reporter gene experiments with a HNF-3 gamma expression vec…
Caracterización molecular de la anemia refractaria con sideroblastos en anillo mediante un panel de secuenciación de segunda generación
2019
Los síndromes mielodisplásicos (SMD) son un grupo heterogéneo de neoplasias hematológicas que presentan citopenias, mielodisplasia, hematopoyesis ineficaz y un riesgo variable de transformación a leucemia mieloide aguda (t-LMA). Los SMD con sideroblastos en anillo (SMD-SA) constituyen aproximadamente el 10-12% de todos los SMD y en médula ósea muestran SA, eritroblastos con depósitos anormales de ferritina, en porcentaje igual o superior al 5%. El objetivo terapéutico en los SMD-SA es mejorar las citopenias y su sintomatología, en especial el síndrome anémico. La administración de eritropoyetina y el soporte transfusional con concentrados de hematíes son las opciones terpéuticas de primera …
Highly transitive actions of groups acting on trees
2015
We show that a group acting on a non-trivial tree with finite edge stabilizers and icc vertex stabilizers admits a faithful and highly transitive action on an infinite countable set. This result is actually true for infinite vertex stabilizers and some more general, finite of infinite, edge stabilizers that we call highly core-free. We study the notion of highly core-free subgroups and give some examples. In the case of amalgamated free products over highly core-free subgroups and HNN extensions with highly core-free base groups we obtain a genericity result for faithful and highly transitive actions. In particular, we recover the result of D. Kitroser stating that the fundamental group of …
Endoplasmic Reticulum stress reduces COPII vesicle formation and modifies Sec23a cycling at ERESs
2013
AbstractExit from the Endoplasmic Reticulum (ER) of newly synthesized proteins is mediated by COPII vesicles that bud from the ER at the ER Exit Sites (ERESs). Disruption of ER homeostasis causes accumulation of unfolded and misfolded proteins in the ER. This condition is referred to as ER stress. Previously, we demonstrated that ER stress rapidly impairs the formation of COPII vesicles. Here, we show that membrane association of COPII components, and in particular of Sec23a, is impaired by ER stress-inducing agents suggesting the existence of a dynamic interplay between protein folding and COPII assembly at the ER.
Darboux curves on surfaces I
2017
International audience; In 1872, G. Darboux defined a family of curves on surfaces of $\mathbb{R}^3$ which are preserved by the action of the Mobius group and share many properties with geodesics. Here, we characterize these curves under the view point of Lorentz geometry and prove that they are geodesics in a 3-dimensional sub-variety of a quadric $\Lambda^4$ contained in the 5-dimensional Lorentz space $\mathbb{R}^5_1$ naturally associated to the surface. We construct a new conformal object: the Darboux plane-field $\mathcal{D}$ and give a condition depending on the conformal principal curvatures of the surface which guarantees its integrability. We show that $\mathcal{D}$ is integrable w…
Foliations of $\mathbb{S}^3$ by Cyclides
2018
Throughout the last 2–3 decades, there has been great interest in the extrinsic geometry of foliated Riemannian manifolds (see [2], [4] and [22]). ¶One approach is to build examples of foliations with reasonably simple singularities with leaves admitting some very restrictive geometric condition. For example (see [22], [23] and [17]), consider in particular foliations of $\mathbb{S}^{3}$ by totally geodesic or totally umbilical leaves with isolated singularities. ¶The article [14] provides families of foliations of $\mathbb{S}^{3}$ by Dupin cyclides with only one smooth curve of singularities. Quadrics and other families of cyclides like Darboux cyclides provide other examples. These foliat…
La théorie des lignes parallèles de Johann Heinrich Lambert
2014
International audience; The memoir "Theory of parallel lines" (1766) by Johannes Heinrich Lambert is one of the founding texts of hyperbolic geometry, even though his author conceived it as an attempt to show that this geometry does not exist. In fact, Lambert developed that theory with the hope of finding a contradiction. In doing so, he obtained several fundamental results of hyperbolic geometry. This was sixty years before the first writings of Lobachevsky and Bolyai appeared in print. This book contains the first complete translation of Lambert's memoir as well as mathematical and historical commentaries.
Effet anti-tumoral de l'acide docosahexaénoïque : implication des microARNs et du TNFalpha
2015
Docosahexaenoic acid (DHA) is an omega-3 polyunsaturated fatty acid with anti-inflammatory and anti-tumoral properties. The anti-tumor effect of DHA in colorectal cancer might be attributed to direct anti-proliferative action on cancer cells and to its ability to reduce inflammatory status involved in tumor growth. Tumor Necrosis Factor-alpha (TNFa) is an inflammatory cytokine with paradoxical effect in cancer biology. According to the cellular context, TNFa activates RIP1 kinase dependent signaling pathway leading to proliferation or cell death. Our aim was to evaluate the role of TNFa in anti-proliferative effect of DHA in colon cancer cells and to precise the molecular mechanisms regulat…
Influence of aluminates phases hydration in presence of calcium sulfate on silicates phases hydration : consequences on cements optimum sulfate
2012
The mechanical properties of hydrated cements need to be optimized according to the nature of cement products. Among the factors of optimization, the addition of calcium sulphate intended to regulate the reactivity of tricalcium aluminate (C3A), in quantity and quality in cement is an essential parameter.The advancement of knowledge on the mechanisms of hydration of each cement phase allows a study devoted entirely to the concept of optimum of sulphate. We studied simple system that we complicated and we studied the evolution of hydration, porosity and mechanical properties of cement at different age. The first system studied was the mixture C3S/gypsum, the objective was to determine whethe…
Auditory P3a response to native and foreign speech in children with or without attentional deficit
2023
The aim of this study was to investigate the attentional mechanism in speech processing of native and foreign language in children with and without attentional deficit. For this purpose, the P3a component, cognitive neuromarker of the attentional processes, was investigated in a two-sequence two-deviant oddball paradigm using Finnish and English speech items via event-related potentials (ERP) technique. The difference waves reflected the temporal brain dynamics of the P3a response in native and foreign language contexts. Cluster-based permutation tests evaluated the group differences over the P3a time window. A correlation analysis was conducted between the P3a response and the attention sc…