Éditeur(s) : HAL CCSD
Résumé : National audience
Due to their extended indications, intravenous immunoglobulins (IVIg) are increasingly used in hospital setting. After injection, classical IVIg half-life reaches more than 3weeks. IVIg result from the pooling of many blood donations and contain all natural antibodies usually found in the general population. Administered antibodies are known to interfere with many diagnostic assays, particularly those used for infectious serology. It is not recommended to perform serological determination after IVIg infusion. It is recommended to keep a delay of at least 4months after IVIg infusion before doing any serological assay; failure to do so will result in misinterpretation of biological findings. Interpretation of any serological test after IVIg administration should be particularly cautious.
Presse medicale

hal-01477208
https://hal-univ-rennes1.archives-ouvertes.fr/hal-01477208
DOI : 10.1016/j.lpm.2016.03.009
PUBMED : 27132942

Résumé : L’objet de cette thèse est l’étude des comportements mécanique et à la corrosion d’un nouveau système de fondation, dit pieux SPIRMEC, adapté aux structures légères. Le travail s’est focalisé sur deux grands aspects. Le premier aspect concerne l’analyse du comportement sous chargement axiale des pieux SPIRMEC sur la base de l’expérimentation et de la modélisation numérique dans un sol mou non cohésif. Quant au deuxième aspect, il traite du problème de la corrosion de l’acier constituant le pieu dans un environnement tropical humide. Le comportement des pieux SPIRMEC sous une charge axiale de traction, dans un sol fin non cohésif, a montré le développement d’une surface cylindrique de rupture. Celle-ci ne dépend pas de la configuration géométrique des pieux tel que : l’espacement S, le diamètre d’hélice Dh et le diamètre du tube d. En adoptant ce critère de rupture et à l’aide d’une analyse statistique des données, nous avons proposé quatre méthodes analytiques de prédiction de la capacité portante des pieux SPIRMEC à partir des essais in-situ et au laboratoire qui sont: •Méthode CPT basée sur la résistance de pointe pénétromètrique (essai CPT), •Méthode MPT basée sur la pression limite pressiomètrique (essai MPT), •Méthode du couple d’installation, •Méthode analytique basée sur les paramètres de cisaillement de sol notamment l’angle de frottement interne (essais triaxial et boîte de cisaillement). Ces méthodes tiennent compte de la géométrie du pieu, du procédé de mise en oeuvre et de la compacité du sol. L’analyse de performance des méthodes proposées a montré que les méthodes analytique et CPT représentent mieux le comportement des pieux testés. La modélisation numérique du comportement des pieux SPIRMEC sous charge axiale de traction a été également étudiée à l’aide du code de calcul Plaxis 2D. Un modèle axisymétrique a été adopté pour modéliser la géométrie de la structure. Le modèle de comportement hardening soil a été retenu pour modéliser le comportement élastoplastiq des couches de sol. Un modèle élastique linéaire a été retenu pour le pieu. Quant au comportement de l’interface sol-structure, il a été pris en compte par un modèle élastoplastique basé sur les critères de Mohr-Coulomb. L’expansion du sol résultant de l’installation des pieux a été approchée par une cavité cylindrique. Cette dernière a été modélisée par des déformations volumiques anisotropes. Nous avons constaté, qu’appliquer une déformation volumique de l’ordre de 40% permet une bonne concordance entre les résultats numériques et expérimentaux. L’étude paramétrique nous a également permis de constater l’existence d’une variation linéaire entre la capacité portante et l’espacement S. Le comportement de l’acier galvanisé dans le sol a été également étudié au moyen de trois approches: électrochimique, visuelles grâce au microscope électronique et gravimétrique. Les tests électrochimiques de corrosion du zinc ont été réalisés dans la solution de sol artificielle pour deux périodes bien distinctes : saison des pluies et après 8 mois de contact sol-pieu. Une forte dépendance est constatée de la vitesse de corrosion de zinc au pH et à la conductivité de la solution. La vitesse de corrosion est plus importante en saison des pluies qu’après 8 mois de contact de pieu avec le sol. Les fortes concentrations en sulfates semblent augmenter la vitesse de corrosion. Les analyses menées au MEB montrent que la zone de fluctuation de nappe et en surface externe (sol/air) sont les zones les plus corrodées. La comparaison entre les différentes techniques d’évaluation de la vitesse de corrosion a montré que l’eau de nappe peut être utilisée comme un milieu représentatif du profil chimique d’un sol non cohésif et légèrement granulaire.
The purpose of this thesis is to study the both behaviors mechanical and of the corrosion of a new foundation system, called spirec piles, for lightweight structures. The work was based on two main aspects. The first aspect concerns the analysis of behavior of the spirmec piles under axial loading on the basis of experimental and numerical modeling in a non-cohesive soft soil. On the second aspect, it addresses the problem of corrosion of steel forming the pile in a humid tropical environment. The behavior of the tested piles under axial traction load, in a non-cohesive soil, showed the development of a cylindrical surface of failure. This does not depend on the geometrical configuration of the tested piles such that: the spacing s, the helix diameter dh and the diameter of the shaft. By adopting this failure criterion and using statistical data analysis, we proposed four analytical methods for predicting the bearing capacity of the piles from in-situ and laboratory tests, which are: cpt method based on tip resistance penetrometer (cpt test), mpt method based on pressuremeter limit pressure (test mpt), method of installation torque and analytical method based on the shear parameters of soil (triaxial tests and shear box). These methods take into account the geometry of the pile, the method and implementation of soil compaction. Performance analysis of the proposed methods showed that the analytical methods and cpt represent better the behavior of piles tested. An axisymmetric condition was assumed to model this geometry in two-dimensional space. In this study, we proposed to model the pipe screw pile with plates elements available in plaxis 2d. The helixes were modeled as circular disks. Interface elements were incorporated along the pile to simulate the soil-pile interaction. Hardening soil model was chosen to describe the soil with drained behavior was assigned for all layers. Linear elastic for pile and elastic plastic model based on the mohr-coulomb criterion was used to describe the interface behavior. The lateral expansion generated by the pile shaft was modeled by anisotropic volumetric strains (ɛxx=ɛzz, ɛyy=0). The pile behavior under tensile loading at different volumetric strains, it is clear that the best fit was obtained at volumetric strain of 40%. The parametric study also allowed us to establish the existence of a linear variation between the bearing capacity and spacings. The behavior of the galvanized steel in the ground has also been studied using three approaches such as: electrochemical, microscopic imaging and gravimetrically. Electrochemical tests of the corrosion of the zinc have been made in artificial soil solution into two periods, the rainy season and after eight months of contact soil-pile. Is a strong dependence of the observed corrosion rate of the zinc at the ph and conductivity of the solution. The corrosion rate is higher in the rainy season compared to eight months of contact of the pile with soil. High sulfate concentrations increase the rate of corrosion. The meb analysis shows that the fluctuation zone of the water table is the most corroded area. Comparison between the different methods of evaluating the corrosion rate showed that the ground water may be used as a representative profile of the chemical environment of a non-cohesive soil and slightly granular.

http://www.theses.fr/2014AGUY0790/document

Éditeur(s) : Springer
Résumé : The Balearic Basin is a young basin composed of thick Plio-Quaternary sediments, including active gravity sedimentation. During the Quaternary, gravity processes deposited (1) turbidite systems, either as symmetrical fans (Petit-Rhone and Valencia fans) or asymmetrical ridges (Marseille-Planier, Grand- Rhone and Pyreneo-Languedocian ridges) and (2) several mass-transport deposits, indicating recurrent sedimentary failures of the margin. This paper synthesizes previous works and proposes a chronological sedimentary evolution for the basin. Except for the last 20 ka, the chronostratigraphy remains poorly constrained but should soon be established for the last 500 ka, based on the PROMESS1 drillings on the outer shelf of the Gulf of Lions, and hopefully for the last 30 Ma, based on ultra-deep drilling in the deep basin from aboard the Chikyu research vessel (IODP proposal Pre699).
Geo-Marine Letters (0276-0460) (Springer), 2006-12 , Vol. 26 , N. 6 , P. 347-359

Droits : 2006 Springer Science+Business Media
http://archimer.ifremer.fr/doc/2006/publication-2171.pdf
DOI:10.1007/s00367-006-0044-0
http://archimer.ifremer.fr/doc/00000/2171/

Éditeur(s) : HAL CCSD Elsevier
Résumé : International audience
This study aimed to identify factors associated with virological response (VR) to raltegravir (RAL)-containing regimens in 468 treatment-experienced but integrase inhibitor-naive HIV-1 patients receiving a RAL-containing regimen. VR was defined at Month 6 (M6) as HIV-1 RNA viral load (VL) <50 copies/mL. The impacts on VR of baseline integrase mutations, VL, CD4 count, genotypic sensitivity score for nucleoside reverse transcriptase inhibitors, non-nucleoside reverse transcriptase inhibitors and protease inhibitors, and the number of new antiretrovirals used for the first time associated with RAL were investigated. For patients with VL >50 copies/mL at M6, integrase mutations selected were characterised. Median baseline VL was 4.2 log(10)copies/mL (IQR 3.3-4.9 log(10) copies/mL) and CD4 count was 219 cells/mm(3) (IQR 96-368 cells/mm(3)). At M6, 71% of patients were responders. In multivariate analysis, baseline VL and CD4 count and ≥ 2 new antiretrovirals among darunavir, etravirine, maraviroc and enfuvirtide were associated with VR to RAL. Neither HIV-1 subtype nor baseline integrase polymorphisms were associated with VR to RAL. Among 63 failing patients at M6, selection of ≥ 1 change in the integrase gene was observed in 49 (77.8%), and 27/63 (42.9%) were considered as RAL-associated resistance mutations. Factors independently associated with the occurrence of ≥ 1 RAL-associated resistance mutation were VL at failure >3 log(10) and having no new drugs associated with RAL. RAL showed great potency in treatment-experienced patients. The number of new drugs associated with RAL was an important factor associated with VR. HIV-1 subtype and baseline integrase polymorphisms do not influence the RAL VR.
ISSN: 0924-8579

hal-00875083
https://hal.archives-ouvertes.fr/hal-00875083
DOI : 10.1016/j.ijantimicag.2013.02.016
PUBMED : 23562640

Éditeur(s) : HAL CCSD
Résumé : International audience
Background Orodental diseases include several clinically and genetically heterogeneous disorders that can present in isolation or as part of a genetic syndrome. Due to the vast number of genes implicated in these disorders, establishing a molecular diagnosis can be challenging. We aimed to develop a targeted next-generation sequencing (NGS) assay to diagnose mutations and potentially identify novel genes mutated in this group of disorders. Methods We designed an NGS gene panel that targets 585 known and candidate genes in orodental disease. We screened a cohort of 101 unrelated patients without a molecular diagnosis referred to the Reference Centre for Oro-Dental Manifestations of Rare Diseases, Strasbourg, France, for a variety of orodental disorders including isolated and syndromic amelogenesis imperfecta (AI), isolated and syndromic selective tooth agenesis (STHAG), isolated and syndromic dentinogenesis imperfecta, isolated dentin dysplasia, otodental dysplasia and primary failure of tooth eruption. Results We discovered 21 novel pathogenic variants and identified the causative mutation in 39 unrelated patients in known genes (overall diagnostic rate: 39%). Among the largest subcohorts of patients with isolated AI (50 unrelated patients) and isolated STHAG (21 unrelated patients), we had a definitive diagnosis in 14 (27%) and 15 cases (71%), respectively. Surprisingly, COL17A1 mutations accounted for the majority of autosomal-dominant AI cases. Conclusions We have developed a novel targeted NGS assay for the efficient molecular diagnosis of a wide variety of orodental diseases. Furthermore, our panel will contribute to better understanding the contribution of these genes to orodental disease. Trial registration numbers NCT01746121 and NCT02397824
Journal of Medical Genetics

hal-01272929
https://hal-univ-rennes1.archives-ouvertes.fr/hal-01272929
DOI : 10.1136/jmedgenet-2015-103302
PUBMED : 26502894

Éditeur(s) : EDP Sciences
Résumé : For centuries, several species of prawns and crabs have been raised from wild-caught juveniles in coastal brackish-water fish ponds in various countries of south east Asia. The Indonesian "tambaks" are well known examples of such traditional practices. In western countries, since the turn of the century, advances of marine biology and fast increase of marine fisheries enabled the development of large-scale production and release of larval stages of American and European lobsters in a fruitless attempt to restock natural populations. After the Second World War, the increasing demand for crustaceans in United States and Japan was satisfied by opening new prawn fisheries all over the world. A major breakthrough was achieved with the development of hatchery technologies for the penaeid prawn Penaeus japonicus (Hudinaga, 1942 in Japan) and the caridean prawn Macrobrachium rosenbergii (Ling, 1969 in Malaysia), which occurred during the first decades of the second half of this century. Together with the increasing market demand in developed countries for sea food, this led to a considerable interest of both public agencies and private investors in marine shrimp and prawn culture. In western countries, a large number of pioneering commercial ventures, often based on assumptions not scientifically founded, failed. Nevertheless, the aquaculture production of prawns mainly based on wild-caught juveniles increased in South-East Asia and Central America during the 1980s. This overall positive trend should not hide important failures which occurred at a local scale, such as the Taiwanese crisis of 1988 due principally to environmental degradation, resulting in severe disease problems and a near collapse of the farming activity. Following the early period of hatchery technology development, the major scientific achievements were related to food requirements and formulation of compound diets for larvae, juveniles and adults and to a better knowledge of diseases caused by bacteria and several viruses which have been identified from hatcheries and intensive farming ponds. Additional new technological advances have emerged from recent research in the fields of physiology (endocrinology) and genetics. By far, the major part of the world production of marine crustaceans relies on penaeid prawns and, to a lesser extent, on Macrobrachium species. However, some other species of marine crustaceans have potential for aquaculture. The economic aspects of marine crustacean aquaculture should be considered together with those of the fishing industry: market prices are rather similar, depending on the quality of the product. The balance between market demand and production is an important constraint which, in turn, establishes the success of prawn farming. Since the early 1980s, crustacean aquaculture has increased tremendously in both Asia and America: the world production for 1991 approximated 700,000 tons, with more than 600,000 tons from penaeid prawn culture.
Pendant des siècles, quelques espèces de crevettes et de crabes ont été élevées à partir d'individus juvéniles capturés dans le milieu naturel, dans des bassins à poissons d'eau saumâtre de différents pays d'Asie du Sud-Est. Les « tambaks » indonésiens sont des exemples bien connus de ces pratiques traditionnelles. Dans les pays occidentaux, depuis le début du siècle, les progrès réalisés en biologie marine et la croissance rapide des pêches maritimes ont permis le développement de la production à grande échelle de stades larvaires des homards européen et américain, dans une vaine tentative de reconstitution des stocks naturels. Après la Seconde Guerre mondiale, la demande croissante des Etats-Unis et du Japon a été satisfaite par l'ouverture de nouvelles pêcheries de crevettes dans l'océan mondial. Un progrès décisif a été réalisé avec la mise au point des techniques d'écloserie pour la crevette Pénaeidé Penaeus juponicus (Hudinaga, 1942 au Japon) et la crevette Caridé Macrobrachium rosenbergii (Ling, 1969 en Malaisie), qui sont apparues au cours des premières décennies de la seconde moitié de ce siècle. Parallèlement à la demande croissante du marché des pays développés pour les produits de la mer, ce résultat s'est traduit par un intérêt considérable porté à l'élevage des crevettes marines de la part des institutions de recherche et des investisseurs. Dans les pays occidentaux, un grand nombre de tentatives d'élevage commerciales, fondées sur des considérations non scientifiquement établies, ont échoué. Néanmoins, la production aquacole de crevettes reposant sur la capture d'animaux juvéniles dans la nature, s'est développée en Asie du Sud-Est et en Amérique Centrale au cours des années 1980. Cette tendance globalement positive ne doit pas dissimuler les faillites importantes qui se sont produites à l'échelle locale, comme la crise des élevages de Taiwan en 1988, causée principalement par une dégradation de l'environnement, entraînant l'apparition de problèmes pathologiques sévères et une disparition presque totale de l'activité d'élevage. Après la période pionnière du développement de la technologie d'écloserie, les principaux acquis scientifiques concernent les besoins alimentaires et la formulation d'aliments composés pour les larves, les jeunes et les adultes, et une meilleure connaissance des maladies bactériennes et virales qui interviennent dans les écloseries et les fermes d'élevage intensif. De nouveaux progrès techniques complémentaires ont vu le jour à la suite de recherches dans les domaines de la physiologie (endocrinologie) et de la génétique. De loin, la majeure partie de la production mondiale de Crustacés marins repose sur les crevettes Pénaeidés et, dans une moindre mesure, sur des espèces de Macrobrachium. Cependant, quelques autres espèces de Crustacés marins intéressent potentiellement l'aquaculture. Les aspects économiques de l'aquaculture de crustacés marins doivent être considérés avec ceux de l'industrie des pêches maritimes : les prix du marché sont à peu près les mêmes, et dépendent de la qualité du produit. Le rapport entre la demande du marché et la production est une contrainte importante qui à son tour, détermine les conditions du succès de l'élevage de crevettes. Depuis le début des années 1980, l'aquaculture de crustacés a augmenté considérablement en Asie et en Amérique : la production mondiale pour 1991 avoisine 700 000 tonnes, avec plus de 600 000 tonnes provenant des élevages de crevettes Pénaeidés.
Aquatic Living Resources (0990-7440) (EDP Sciences), 1993-10 , Vol. 6 , N. 4 , P. 319-329

Droits : IFREMER-Gauthier-Villars, 1993
http://archimer.ifremer.fr/doc/00190/30119/28587.pdf
DOI:10.1051/alr:1993033
http://archimer.ifremer.fr/doc/00190/30119/

Éditeur(s) : HAL CCSD American Physical Society
Résumé : International audience
We investigate a class of granular materials characterized by the possibility of interlocking between the particles. The interlocking is modeled by its effect through rolling resistance depending on relative rotation and normal force at the contact points and involving a single parameter analogous to the sliding friction coefficient. The model, which is introduced in the framework of the contact dynamics, method, is applied to simulate the simple shear of a large granular sample. We present a detailed analysis regarding the influence of rolling and sliding friction parameters on the macroscopic response in terms of shear strength, fabric properties, and force transmission. Interestingly, two distinct regimes can be distinguished in which the steady-state shear strength is controlled by either rolling resistance or sliding friction. The relative contributions of rolling and sliding contacts to the shear strength are consistent with the same two regimes. Interlocking strongly affects the force network by enhancing the arching effect and thus increasing the relative importance of weak contact forces and torques, which is reflected in a decreasing power-law probability distribution of the contact forces and torques below the mean. Due to the combined effect of friction and interlocking, the force-carrying backbone takes an increasingly columnar aspect involving a low fraction of particles. Our data suggest that the nature of the weak contact network is strongly affected by the formation of these columns of particles which do not need to be propped laterally. In particular, in the limit of high rolling resistance and sliding friction, the role of the weak network of contacts is no longer to prop the force chains, but, like the strong contact network, to actively sustain the deviatoric load imposed on the system.
ISSN: 1539-3755

hal-00412020
https://hal.archives-ouvertes.fr/hal-00412020
DOI : 10.1103/PhysRevE.78.021301

Éditeur(s) : HAL CCSD American Society of Tropical Medicine and Hygiene
Résumé : International audience
From September 2013 to July 2014, several gold miners working in the tropical forest consulted the Maripasoula Health Center in French Guiana for edema and findings consistent with right cardiac failure. Of the 42 cases of beriberi that were diagnosed, one patient died. The laboratory and clinical investigation demonstrated vitamin B1 deficiency in most of the patients tested. Furthermore, 30 of 42 patients responded favorably to 500 mg of intravenous or intramuscular thiamine supplementation. In addition, dietary investigation showed insufficient thiamine intake in these patients. We concluded that patients had acquired beriberi because of diet restrictions, hard labor, and infectious diseases, notably malaria. In 2016, cases were still being reported. We recommend screening for compatible symptoms in gold miners, thiamine supplementation, and nutritional intervention
ISSN: 0002-9637

inserm-01503899
http://www.hal.inserm.fr/inserm-01503899
http://www.hal.inserm.fr/inserm-01503899/document
http://www.hal.inserm.fr/inserm-01503899/file/2017%2C%20Mosnier%20-%20A%20Large%20Outbreak%20of%20Thiamine%20Deficiency%20among%20Illegal%20Gold%20Miners%20in%20French%20Guiana.pdf
DOI : 10.4269/ajtmh.15-0906

Éditeur(s) : HAL CCSD Elsevier
Résumé : International audience
Background & Aims: The severity of liver diseases is exacerbated by the death of hepatocytes, which can be induced by the sensing of pathogen associated molecular patterns (PAMPs) derived from the gut microbiota. The molecular mechanisms regulating these cell death pathways are poorly documented. In this study, we investigated the role of the receptor interacting protein kinase 1 (RIPK1), a protein known to regulate cell fate decisions, in the death of hepatocytes using two in vivo models of PAMP-induced hepatitis. Methods: Hepatitis was induced in mice by independent injections of two different bacterial PAMPs: lipopolysaccharide (LPS) and unmethylated CpG oligodeoxynucleotide (CpG-DNA) motifs. The role of RIPK1 was evaluated by using mice specifically lacking RIPK1 in liver parenchymal cells (Ripk1(LPC-KO)). Administration of liposome-encapsulated clodronate served to investigate the role of Kupffer cells in the establishment of the disease. Etanercept, a tumor necrosis factor (TNF)-decoy receptor, was used to study the contribution of TNF-alpha during LPS-mediated liver injury. Results: Whereas RIPK1 deficiency in liver parenchymal cells did not trigger basal hepatolysis, it greatly sensitized hepatocytes to apoptosis and liver damage following a single injection of LPS or CpG-DNA. Importantly, hepatocyte death was prevented by previous macrophage depletion or by TNF inhibition. Conclusions: Our data highlight the pivotal function of RIPK1 in maintaining liver homeostasis in conditions of macrophage-induced TNF burst in response to PAMPs sensing. Lay summary: Excessive death of hepatocytes is a characteristic of liver injury. A new programmed cell death pathway has been described involving upstream death ligands such as TNF and downstream kinases such as RIPK1. Here, we show that in the presence of LPS liver induced hepatic injury was due to secretion of TNF by liver macrophages, and that RIPK1 acts as a powerful protector of hepatocyte death. This newly identified pathway in the liver may be helpful in the management of patients to predict their risk of developing acute liver failure. (C) 2017 European Association for the Study of the Liver. Published by Elsevier B.V. All rights reserved.
ISSN: 0168-8278

hal-01532060
https://hal-univ-rennes1.archives-ouvertes.fr/hal-01532060
DOI : 10.1016/j.jhep.2017.01.005
PUBMED : 28088582

Éditeur(s) : HAL CCSD Elsevier Masson
Résumé : International audience
The Société de pneumologie de langue française defines acute exacerbation of chronic obstructive pulmonary disease (AE COPD) as an increase in daily respiratory symptoms, basically duration ≥ 48h or need for treatment adjustment. Etiology of EA COPD are mainly infectious, viral (rhinovirus, influenzae or parainfluenzae virus, coronavirus, adenovirus and respiratory syncytial virus) or bacterial (Haemophilus influenzae, Streptococcus pneumoniae, or Moraxella catarrhalis). Pollutant exposure can also lead to AE COPD, such as NO2, SO2, ozone or particulates (PM10 and PM2.5). In 30% the etiology remains unknown. Differential diagnoses of AE COPD include infectious pneumonia, pneumothorax, acute heart failure and pulmonary embolism. Presences of signs of severity impose hospitalization: signs of respiratory distress, shock, acute confusion but also fragile patients, insufficient home support or absence of response to initial treatment. AE COPD treatments consist on increase in bronchodilators, chest physiotherapy, and antibiotics if sputum is frankly purulent. Systemic corticosteroids should not be systematic.Recommended dose is 0.5 mg/kg on short course (7 days). During hospitalization, oxygen supplementation and thromboprophylaxis could be prescribed. The main interest in noninvasive ventilation is persistent hypercapnia despite optimal medical management. During ambulatory management or hospitalization, clinical assessment at 48-72h is mandatory. L’exacerbation aiguë de bronchopneumopathie chronique obstructive (EA BPCO) représente un événement important dans l’histoire naturelle de la BPCO, notamment en cas d’hospitalisation. Les EA BPCO interviennent dans la gravité et l’évolution de la BPCO ; et leur prévention est un des objectifs principal des traitements de fond.
La Société de pneumologie de langue française définie l’exacerbation aiguë de bronchopneumopathie chronique obstructive (EA BPCO) comme une majoration des symptômes respiratoires au-delà des variations quotidiennes, en pratique, d’une durée ≥ 48h ou justifiant une modification thérapeutique. L’étiologie de ces EA BPCO est principalement infectieuse, virale (rhinovirus, virus influenzae et parainfluenzae, coronavirus, adénovirus et virus respiratoire syncytial) ou bactérienne (principalement Haemophilus influenzae, Streptococcus pneumoniae et Moraxella catarrhalis). Elles peuvent également résulter de l’exposition à certains polluants comme le NO2, le SO2, l’ozone et la pollution particulaire (PM10 et PM2,5). L’étiologie reste indéterminée dans près de 30 % des cas. Les diagnostics différentiels des EA BPCO incluent les pneumopathies infectieuses, les pneumothorax, les poussées d’insuffisance cardiaque et les embolies pulmonaires. La présence de signes de gravité conditionnent l’hospitalisation : signes d’insuffisance respiratoire aiguë, de choc ou de défaillance neurologique, mais aussi en cas de patient fragile, d’absence de soutien familial à domicile ou d’absence de réponse au traitement initial. Le traitement d’une EA BPCO consiste en une majoration des bronchodilatateurs, une kinésithérapie respiratoire, une antibiothérapie en cas d’expectoration franchement purulente.La prescription de corticoïdes systémiques ne doit pas être systématique. La dose recommandée est de 0,5 mg/kg sur une courte période (7 jours). Lors d’une hospitalisation, une oxygénothérapie et une thromboprophylaxie peuvent être prescrite. La ventilation noninvasiveest principalement indiquée en cas de persistance d’une hypercapnie malgré un traitement médical optimal. Que le patient soit pris en charge en ambulatoire ou en hospitalisation, une réévaluation clinique à 48-72h est indispensable.
ISSN: 0755-4982

hal-01117949
https://hal-univ-rennes1.archives-ouvertes.fr/hal-01117949
https://hal-univ-rennes1.archives-ouvertes.fr/hal-01117949/document
https://hal-univ-rennes1.archives-ouvertes.fr/hal-01117949/file/Prise%20en%20charge%20des%20exacerbations_accepted.pdf
DOI : 10.1016/j.jeurea.2015.02.002

Éditeur(s) : HAL CCSD
Résumé : International audience
In many geological reservoirs, open fractures or fault zones generally induce high spatial variability of hydrodynamical properties and shape the main deep-seated flow paths. It is of crucial interest to determine their structure and properties in order to achieve a sound and sustained exploitation of resources or to estimate the risk of failure of any underground storage. Tiltmeters have emerged as new tools to observe deformation generated by groundwater flow. As such instruments are highly sensitive to pressure gradients, they are perfectly suited for monitoring channelized flow in connected fractures and fault zones. Hence, they provide a unique insight of these reservoirs' geometry and dynamics over broad time scales. Here we demonstrate that continuous tilt data from surface long baseline tiltmeters (LBT) can be used alone to evaluate the general functioning of a fractured hardrock system and estimate the hydraulic properties of its main conductive features. The study is applied to the pumping site of Ploemeur observatory (Brittany, France) which is well documented and instrumented, and therefore forms a convenient setting for introducing LBT as tools for fractured media hydrology. On the short term, tilt signals are strongly correlated with pumping cycles and associated head level changes in well-connected boreholes. Besides, when pumps are stopped the maximal tilt direction is systematically perpendicular to a subvertical fault zone whose azimuth of strike has thereby been refined down to degree precision. By using a semi-analytical model of deformation, we establish the link between tilt and pressure change during pumping interruptions which then allows for hydraulic properties estimation from tilt measurements only. Finally, we validate our results with previous estimates obtained from other studies and discuss the orientation of future work that could enhance these estimates.
AGU Fall Meeting 2014
San Francisco, United States

insu-01093437
https://hal-insu.archives-ouvertes.fr/insu-01093437

Éditeur(s) : HAL CCSD Elsevier
Résumé : International audience
We developed a new granular material (MatIV) to study experimentally landscape evolution in active mountain belt piedmonts. Its composition and related physical properties have been determined using empirical criteria derived from the scaling of deformation, erosion-transport and sedimentation natural processes. MatIV is a water-saturated composite material made up with 4 granular components (silica powder, glass microbeads, plastic powder and graphite) whose physical, mechanical and erosion-related properties were measured with different laboratory tests. Mechanical measurements were made on a modified Hubbert-type direct shear apparatus. Erosion-related properties were determined using an experimental set-up that allows quantifying the erosion/sedimentation budget from tilted relaxation topographies. For MatIV, we also investigated the evolution of mean erosion rates and stream power erosion law exponents in 1D as a function of slope.;Our results indicate that MatIV satisfies most of the defined criteria. It deforms brittlely according to the linear Mohr-Coulomb failure criterion and localizes deformation along discrete faults. Its erosion pattern is characterized by realistic hillslope and channelized processes (slope diffusion, mass wasting, channel incision). During transport, eroded particles are sorted depending on their density and shape, which results in stratified alluvial deposits displaying lateral fades variations. To evaluate the degree of similitude between model and nature, we used a new experimental device that combines accretionary wedge deformation mechanisms and surface runoff erosion processes. Results indicate that MatIV succeeded in producing detailed morphological and sedi-mentological features (drainage basin, channel network, terrace, syntectonic alluvial fan). Geometric, kinematic and dynamic similarity criteria have been investigated to compare precisely model to nature. Although scaling is incomplete, it yields particularly informative orders of magnitude. With all these characteristics, MatIV appears as a very promising material to investigate experimentally a wide range of scientific questions dealing with relief dynamics and interactions between tectonics, erosion and sedimentation processes.
ISSN: 0040-1951

hal-00669904
https://hal.archives-ouvertes.fr/hal-00669904
DOI : 10.1016/j.tecto.2011.09.029

Éditeur(s) : HAL CCSD American Geophysical Union
Résumé : International audience
After the January 12, 2010, Haiti earthquake, we deployed a mainly offshore temporary network of seismologic stations around the damaged area. The distribution of the recorded aftershocks, together with morphotectonic observations and mainshock analysis, allow us to constrain a complex fault pattern in the area. Almost all of the aftershocks have a N‐S compressive mechanism, and not the expected left‐lateral strike‐slip mechanism. A first‐order slip model of the mainshock shows a N264°E north‐dipping plane, with a major left‐lateral component and a strong reverse component. As the aftershock distribution is sub‐parallel and close to the Enriquillo fault, we assume that although the cause of the catastrophe was not a rupture along the Enriquillo fault, this fault had an important role as a mechanical boundary. The azimuth of the focal planes of the aftershocks are parallel to the north‐dipping faults of the Transhaitian Belt, which suggests a triggering of failure on these discontinuities. In the western part, the aftershock distribution reflects the triggering of slip on similar faults, and/or, alternatively, of the south‐dipping faults, such the Trois‐Baies submarine fault. These observations are in agreement with a model of an oblique collision of an indenter of the oceanic crust of the Southern Peninsula and the sedimentary wedge of the Transhaitian Belt: the rupture occurred on a wrench fault at the rheologic boundary on top of the under‐thrusting rigid oceanic block, whereas the aftershocks were the result of the relaxation on the hanging wall along pre‐existing discontinuities in the frontal part of the Transhaitian Belt.
ISSN: 0094-8276

insu-00643489
https://hal-insu.archives-ouvertes.fr/insu-00643489
https://hal-insu.archives-ouvertes.fr/insu-00643489/document
https://hal-insu.archives-ouvertes.fr/insu-00643489/file/GRL-haiti.2011.pdf
DOI : 10.1029/2011GL049799

Éditeur(s) : HAL CCSD
Résumé : The ovary is not solely the unique source of oocytes necessary for fertilization but also a crucial conductor of endocrine regulations of the reproductive system. In the fetal ovary, oocytes grouped in clusters are surrounded by somatic pre-granulosa cells, altogether delineated by a basement membrane and constituting ovarian cords. The formation of the definitive ovarian functional units requires their fragmentation into follicles formed by a single oocyte surrounded by granulosa cells and delineated by a basement membrane. This partitioning occurs within a tiny period and is dependent on the correct timing of the meiotic process, on an apoptotic wave that specifically targets oocytes and the remodelling of the basement membrane. Follicle formation is a crucial event of ovarian development because the follicle stock formed at the end of this process is non-renewable. Therefore, any disturbance of this process can lead to reproductive abnormalities in adulthood. Recent data on endocrine disruptors displaying estrogenic activity have involved the fragile estrogenic homeostasis in the process. We aimed at better understanding how the endogen estrogen 17b-estradiol (E2) contributes to follicle formation. To assess it, Sprague-Dawley rats were treated with E2 at different doses during follicle formation, /i.e./ in the 3 days following birth. We show that although this treatment impairs the development of the hepatic and ovarian detoxification systems, the female neonate is able to increase its estrogen clearance capabilities. Nevertheless, E2 treatment within this critical period triggers a dose-dependent decrease of oocyte number per ovary. Regardless of the E2 dose, puberty is advanced. All treated females are at least transiently fertile, yet these reproductive capabilities rapidly decline. A high (10 µg/day) dose of E2 leads to a secondary infertility characterized by anovulation that probably result from a dysfunction of the whole reproductive tract. By contrast, a lower (0.1 µg/day) dose of E2, that does not significantly modify neonatal oocyte survival, leads to a progressive reproductive senescence likely due to ovarian failure. Long-term troubles may originate from precocious E2 impact on the ovary since it disturbs ovarian transcriptome and produces many lesions on ovarian cell DNA.
L'ovaire est au cœur de la physiologie de la reproduction féminine. Il est à la fois à l'origine des ovocytes nécessaires à la fécondation et acteur des régulations endocrines du système reproducteur. Les ovocytes de l'ovaire fœtal sont groupés en amas bordés de cellules somatiques et d'une membrane basale, formant les cordons ovariens. Ces cordons ovariens se fragmentent pour former les follicules ovariens: un ovocyte bordé de cellules somatiques et d'une membrane basale. Cette fragmentation se déroule sur une courte période (/in utero/ chez la femme et juste après la naissance chez les rongeurs) et fait intervenir une vague de mort cellulaire programmée touchant les ovocytes pendant leur méiose et un remodelage de la membrane basale. La formation des follicules est une période cruciale du développement ovarien puisque le stock de follicules formés à l'issue de ce processus est non renouvelable. Son altération peut donc être à l'origine de troubles de la fonction de reproduction chez le futur adulte. Il existe une fragile homéostasie œstrogénique en place au moment de la formation folliculaire: chez la femme, l'ovaire se développe /in utero/, sous l'influence des œstrogènes circulants maternels et la production ovarienne fœtale. Chez les rongeurs, les follicules se forment lors de la levée de l'imprégnation hormonale maternelle au moment de la naissance. Nous avons souhaité comprendre comment le 17b-œstradiol (E2), œstrogène endogène, pouvait contribuer à la mise en place des follicules. Pour cela, des rattes Sprague-Dawley ont été traitées pendant la période de formation des follicules avec de l'E2 à différentes doses entre 0.01 et 10 µg/jour. Nos travaux démontrent que le traitement de rattes par des œstrogènes entre leur naissance et 3 jours induit une réduction dose-dépendante de leur nombre d'ovocytes. Bien que le traitement entrave le développement normal du système de détoxication hépatique et ovarien, l'animal est capable d'accroître ses capacités d'élimination des œstrogènes. Ces capacités sont toutefois insuffisantes pour bloquer les effets du traitement. Quelle que soit la dose d'E2 utilisée (0.1 ou 10 µg/jour), la puberté est plus précoce chez les femelles exposées mais toutes sont fertiles, au moins transitoirement. Cependant le traitement induit une dégradation rapide des capacités reproductives. L'E2 modifie la dynamique folliculaire chez l'adulte, longtemps après l'arrêt du traitement. Si une forte dose d'E2 réduit la survie des ovocytes lors de la formation des follicules et conduit à une infertilité secondaire due à un dysfonctionnement général du tractus reproducteur, une dose faible n'affecte pas la survie des ovocytes à court terme mais conduit à une sénescence reproductive précoce vraisemblablement d'origine ovarienne. L'origine de ces troubles pourrait résider dans les effets précoces de l'exposition à E2 : cette molécule altère le transcriptome ovarien et induit de nombreuses lésions de l'ADN des cellules ovariennes.
https://tel.archives-ouvertes.fr/tel-00953657

NNT : 2013REN1S107
tel-00953657
https://tel.archives-ouvertes.fr/tel-00953657
https://tel.archives-ouvertes.fr/tel-00953657/document
https://tel.archives-ouvertes.fr/tel-00953657/file/CHALMEY_Clementine.pdf

Éditeur(s) : HAL CCSD
Résumé : International audience
Background: In French Guiana, a recent study has shown that a major part of the histoplasmosis incidence temporal fluctuations could be explained by climatic factors and thus postulated that disseminated histoplasmosis cases could be in a large proportion due to new infections. The description of the seasonal pattern of histoplasmosis could potentially help to test this new hypothesis. Patients and methods: A study using prospective data from the French Hospital Database for HIV was conducted in order to determine seasonal variations of the incidence of first cases of disseminated histoplasmosis in HIV persons in Cayenne, French Guiana. Single failure Cox proportional hazards models were used. Results: After adjusting for CD4 counts and antiretroviral treatment, the incidence of disseminated histoplasmosis was significantly higher during the Short Wet Season-Long Dry Season than during the Short Dry Season-Long Wet Season (Adjusted Hazard ratio 1.7 (1.1-2.5), P= 0.01). Conclusion: This result gives both valuable epidemiologic information to clinicians and a supplementary argument in favour of the hypothesis that an important proportion of cases were due to recent exposure. Therefore, the use of a primary prophylaxis must be discussed in French Guiana.
J AIDS Clinic Res

Droits : info:eu-repo/semantics/OpenAccess
inserm-00915009
http://www.hal.inserm.fr/inserm-00915009
http://www.hal.inserm.fr/inserm-00915009/document
http://www.hal.inserm.fr/inserm-00915009/file/2012_Hanf_-_Disseminated_Histoplasmosis_seasonal_incidence_variations_a_supplementary_argument_for_recent_infection.pdf
DOI : 10.4172/2155-6113.1000175

Éditeur(s) : HAL CCSD
Résumé : International audience
Chronic obstructive pulmonary disease (COPD) is the chronic respiratory disease with the most important burden on public health in terms of morbidity, mortality and health costs. For patients, COPD is a major source of disability because of dyspnea, restriction in daily activities, exacerbation, risk of chronic respiratory failure and extra-respiratory systemic organ disorders. The previous French Language Respiratory Society (SPLF) guidelines on COPD exacerbations were published in 2003. Using the GRADE methodology, the present document reviews the current knowledge on COPD exacerbation through 4 specific outlines: (1) epidemiology, (2) clinical evaluation, (3) therapeutic management and (4) prevention. Specific aspects of outpatients and inpatients care are discussed, especially regarding assessment of exacerbation severity and pharmacological approach.
Revue Des Maladies Respiratoires

hal-01560287
https://hal-univ-rennes1.archives-ouvertes.fr/hal-01560287
DOI : 10.1016/j.rmr.2017.03.034
PUBMED : 28552256

Éditeur(s) : HAL CCSD Springer Verlag
Résumé : International audience
In this study, we quantify and analyze the spatial and temporal evolution of the surface displacement of Kahrod landslide located in the center of Alborz range (Iran) within the Haraz valley. This landslide represents a threat for this main drainage axis and its numerous infrastructures. We present three sets of displacement vectors based on GPS technique. An 8-benchmark network has been surveyed four times on a 1-year period basis. It provides accurate information on the rate of displacement within the landslide, and addresses the problem of the mechanical resistance of a small hillock, down slope, under the stress imposed by the landslide. Then. this network is densified (57 marks) and measured twice in 6 months using a rapidstatic approach. This yields to a dense description of surface deformation over the whole landslide. Finally, a 1-year time series of permanent GPS recordings is presented and compared to rainfall. Furthermore, we analyze Envisat radar differential interferograms (DInSAR) spanning the same period as permanent GPS. These geodetic data allow to precisely determine the limits of the current sliding zone and to describe the spatial and temporal evolution of surface displacement. The combination of geodesy and field observations leads to a precise description of the past and present kinematics behavior of Kahrod landslide. The chaotic nature of the sliding mass suggests a first catastrophic landslide in a first episode. During the period of observation, the landslide appears to deform quite steadily, and the evidence of short-term correlation between rainfall and deformation amplitude needs to be confirmed by future measurements. Carrying on the acquisition of GPS and InSAR data within the sliding mass but also within adjacent bedrock should give fundamental information with regards to major activation processes (river sapping, water seeping, earthquakes, or failure within the frontal hill of bedrock) and their potential consequences.
ISSN: 1435-9529

hal-00411318
https://hal.archives-ouvertes.fr/hal-00411318
DOI : 10.1016/j.enggeo.2008.02.013

Éditeur(s) : HAL CCSD Elsevier
Résumé : International audience
We use 3-D mechanical modeling representing faults as planar surfaces with frictional properties that obey Coulomb-failure process to explore the long-term slip rates of the Altyn Tagh fault and Kunlun faults in the north Tibetan plateau. Crustal theology is simplified as an elastoplastic upper crust and a viscoelastic lower crust. Far-field GPS velocities and late Quaternary fault slip rates are used to constrain the model results. Rheological tests show that effective fault friction lower than 0.1-0.08 leads to high slip rates that fit with geologically and geodetically determined slip rates of the Kunlun fault (10-11.7 +/- 1.5 mm/yr). Meanwhile, the modeled Altyn Tagh fault reaches slip rates similar to 13.7 mm/yr to similar to 7.8 mm/yr in its central portion, between ranges of the geological slip rates. Associated with high slip rates, our model predicts that central Tibet (similar to 84 degrees E-95 degrees E) from the Altyn Tagh fault to the north of the Himalayan arc accommodates north-south shortening and east-west extension rates of similar to 10-12 mm/yr and similar to 8-10 mm/yr, respectively. We also question the widely accepted idea that interseismic strain is driven at the base of the seismogenic zone by a screw dislocation. If this assumption fails, the presented model implies that interseismic strain around large strike-slip faults could be distributed in a much broader way if the lithosphere deforms as a thin elastic plate rather than an elastic half-space with an embedded dislocation. If this distributed deformation is ignored, and the instantaneous surface deformation field modeled as that resulting from slip on a dislocation below a specified depth embedded in an elastic half-space, the estimated slip rate will inevitably be lower than the true long-term slip rate. This appears to explain why geodetic slip rates proposed for the Altyn Tagh fault (510 mm/yr) are lower than some of the geological slip rates. (C) 2008 Elsevier B.V. All rights reserved.
ISSN: 0012-821X

hal-00411926
https://hal.archives-ouvertes.fr/hal-00411926
DOI : 10.1016/j.epsl.2008.06.049

Éditeur(s) : HAL CCSD Wiley
Résumé : International audience
Clin Microbiol Infect ABSTRACT: Atypical Toxoplasma gondii strains, unrelated to archetypal clonal lineages (I, II, III), have been reported more frequently over the last decade in areas other than Europe and North America. A newly described form of toxoplasmosis, 'Amazonian toxoplasmosis' (AT), has been reported since 2002 in French Guiana. It is characterized by severe cases and atypical strains linked to a neotropical forest-based cycle. We report on the cases of AT that required intensive care management. We performed a prospective observational study on hospitalized adults in the Intensive Care Unit (ICU) from 2002 to 2008. Clinical and laboratory data, microbiological findings and outcomes were recorded. Data, including the ICU simplified acute physiology score and the pneumonia severity index, were calculated. Epidemiological risk factors for AT were assessed through questionnaires. Eleven non-immunodeficient patients were admitted to the ICU in Cayenne for life-threatening pneumonia associated with disseminated toxoplasmosis. Mechanical ventilation was necessary in seven patients, four of whom required immediate orotracheal intubation. Cardiac and ophthalmological abnormalities were found in five and four patients, respectively. One patient died from multiple organ failure. The genetic characterization of Toxoplasma DNA using six microsatellite markers revealed unique and atypical genotypes in eight patients. All patients presented epidemiological risk factors for AT. In French Guiana, significant T. gondii-related infectious syndrome associated with the lungs, a high level of LDH activity and the reported risk factors for AT was strongly suggestive of disseminated toxoplasmosis with a possible trend toward life-threatening pneumonia.
ISSN: 1198-743X

hal-00678752
https://hal-unilim.archives-ouvertes.fr/hal-00678752
DOI : 10.1111/j.1469-0691.2011.03648.x
PUBMED : 21958195

Éditeur(s) : HAL CCSD Elsevier
Résumé : International audience
Chronic liver damage due to viral or chemical agents leads to a repair process resulting in hepatic fibrosis. Fibrosis may lead to cirrhosis, which may progress to liver cancer or a loss of liver function, with an associated risk of liver failure and death. Chlordecone is a chlorinated pesticide used in the 1990s. It is not itself hepatotoxic, but its metabolism in the liver triggers hepatomegaly and potentiates hepatotoxic agents. Chlordecone is now banned, but it persists in soil and water, resulting in an ongoing public health problem in the Caribbean area. We assessed the probable impact of chlordecone on the progression of liver fibrosis in the population of contaminated areas, by developing a mouse model of chronic co-exposure to chlordecone and a hepatotoxic agent, carbon tetrachloride (CCl4). After repeated administrations of chlordecone and CCl4 by gavage over a 12-week period, we checked for liver damage in the exposed mice, by determining serum liver transaminase (AST, ALT) levels, histological examinations of the liver and measuring the expression of genes encoding extracellular matrix components. The co-exposure of mice to CCl4 and chlordecone resulted in significant increases in ALT and AST levels. Chlordecone also increased expression of the Col1A2, MMP-2, TIMP-1 and PAI-1 genes in CCl4-treated mice. Finally, we demonstrated, by quantifying areas of collagen deposition and alpha-SMA gene expression, that chlordecone potentiated the hepatic fibrosis induced by CCl4. In conclusion, our data suggest that chlordecone potentiates hepatic fibrosis in mice with CCl4-induced chronic liver injury
ISSN: 0378-4274

hal-01274228
https://hal-univ-rennes1.archives-ouvertes.fr/hal-01274228
https://hal-univ-rennes1.archives-ouvertes.fr/hal-01274228/document
https://hal-univ-rennes1.archives-ouvertes.fr/hal-01274228/file/Chlordecone%20potentiates%20hepatic%20fibrosis%20%281%29.pdf
DOI : 10.1016/j.toxlet.2016.02.005