Éditeur(s) : HAL CCSD Elsevier
Résumé : International audience
We use first first-principle methods and the Peierls-Nabarro model to evaluate the resistance to glide, characterized by the Peierls stress, of glide systems for end-member MgSiO3 Perovskite at mantle pressures. [010](100) is the easiest glide system in Mg-Perovskite at all pressures. Peierls stresses increase systematically with pressure for all systems except [001](010), indicating the importance of lattice friction at lower mantle pressures. The ratio of the maximum Peierls stress for each system relative to the [010](100) value defines their critical resolved shear stress (CRSS). These CRSS are used in a visco-plastic self-consistent homogenization model to predict the evolution of crystal preferred orientations (CPO) during deformation of polycrystalline Mg-Perovskite. In axial compression, [100] tends to align with the compression direction, in agreement with in situ observations in axial compression experiments. In simple shear, [010] concentrates near the shear direction and (100), although more dispersed, tends to align near the shear plane, consistent with the dominant activity of the easier [010](100) system. The calculated seismic anisotropy for a 100% Mg-Perovskite aggregate using the CPO in simple shear and the elastic constants Of MgSiO3 perovskite at lower mantle pressures and temperatures is weak (>3% for P-waves with and >2% for S-waves) and decreases with increasing temperature and pressure. P-waves show the fastest propagation parallel to the lineation and S-waves fast polarization is in the foliation at 38 GPa and normal to the lineation at 88 GPa. This weak anisotropy is consistent with global seismological observations of a nearly isotropic lower mantle. There are however two regions where strain-induced Mg-Perovskite CPO could contribute to anisotropy; a) low temperature regions in the uppermost lower mantle, where the predicted S-wave polarization anisotropy may attain 1.6% with a fast polarization parallel to the foliation, b) in high high-temperature domains in the D '' layer, where Mg-Perovskite may be the major stable phase, leading to polarization of fast S-waves normal to the lineation for propagation directions at high angle to the lineation and an apparent isotropy for all other propagation directions.
ISSN: 0012-821X

hal-00411460
https://hal.archives-ouvertes.fr/hal-00411460
DOI : 10.1016/j.epsl.2008.03.058

Éditeur(s) : HAL CCSD
Résumé : International audience
Background Chlordecone is a persistent organochlorine insecticide with well-defined estrogenic properties. It was intensively used in the French West Indies until 1993 to control the banana root borer. Because of the long-term contamination of soils and water, the population is currently exposed to chlordecone through food consumption. Chlordecone has been found in the blood of pregnant women and in cord blood. It has been shown to be an endocrine-disrupting chemical and exposure during pregnancy may affect fetal growth. Objectives The objective of our study was to examine the association between prenatal exposure to chlordecone and fetal growth based on the TIMOUN birth cohort conducted in Guadeloupe, with a focus on the potential modification of this relationship by maternal body mass index (BMI) and gestational weight gain (GWG). Methods Chlordecone was determined in cord plasma at birth in 593 babies. Birth weight was the indicator of fetal growth. Maternal pre-pregnancy BMI and GWG were determined. Adherence to GWG recommendations of the US Institute of Medicine based on maternal pre-pregnancy BMI was assessed. Birth weight was analyzed relative to cord blood chlordecone levels using linear and non-linear regression models. Results Overall chlordecone in cord blood was not associated with birth weight, but we found an interaction between chlordecone exposure with GWG and adherence to GWG recommendations. After stratification by GWG, we found a significant U-shaped association between birth weight and chlordecone exposure, within the upper quartiles of GWG or excessive GWG. Conclusion Chlordecone exposure may affect fetal growth, particularly when excessive GWG is present. © 2016 Elsevier Inc.
Environmental Research

hal-01367154
https://hal-univ-rennes1.archives-ouvertes.fr/hal-01367154
DOI : 10.1016/j.envres.2016.08.004
PUBMED : 27560981

Éditeur(s) : HAL CCSD
Résumé : International audience
o abstract
Revue Des Maladies Respiratoires

hal-01647782
https://hal-univ-rennes1.archives-ouvertes.fr/hal-01647782
DOI : 10.1016/j.rmr.2017.07.017
PUBMED : 28939155

Éditeur(s) : HAL CCSD European Respiratory Society
Résumé : IF 8.332
International audience
The respiratory manifestations of eosinophilic granulomatosis with polyangiitis (EGPA) have not been studied in detail. In this retrospective multicentre study, EGPA was defined by asthma, eosinophilia and at least one new onset extra-bronchopulmonary organ manifestation of disease. The study population included 157 patients (mean±SD age 49.4±14.1 years), with a mean±SD blood eosinophil count of 7.4±6.4×109 L-1 at diagnosis. There was a mean±SD of 11.8±18.2 years from the onset of asthma to the diagnosis of EGPA, of 1.4±8.4 years from the first onset of peripheral eosinophilia to the diagnosis of EGPA, and of 7.4±6.4 years from EGPA diagnosis to the final visit. Despite inhaled and oral corticosteroid treatment, the severity of asthma increased 3-6 months before the onset of the systemic manifestations. Asthma was severe in 57%, 48%, and 56% of patients at diagnosis, at 3 years, and at the final visit, respectively. Persistent airflow obstruction was present in 38%, 30%, and 46% at diagnosis, at 3 years, and at the final visit, respectively. In EGPA, asthma is severe, antedates systemic manifestations by a mean of 12 years, and progresses to long-term persistent airflow obstruction despite corticosteroids in a large proportion of patients, which affects long-term management and morbidity. Copyright © 2016 ERS.
ISSN: 0903-1936

hal-01406073
https://hal-univ-rennes1.archives-ouvertes.fr/hal-01406073
DOI : 10.1183/13993003.00097-2016
PUBMED : 27587545

Éditeur(s) : HAL CCSD Wiley
Résumé : International audience
BACKGROUND: An association between education and preterm delivery has been observed in populations across Europe, but differences in methodology limit comparability. We performed a direct cross-cohort comparison of educational disparities in preterm delivery based on individual-level birth cohort data. METHODS: The study included data from 12 European cohorts from Denmark, England, France, Lithuania, the Netherlands, Norway, Italy, Portugal, and Spain. The cohorts included between 2434 and 99 655 pregnancies. The association between maternal education and preterm delivery (22-36 completed weeks of gestation) was reported as risk ratios, risk differences, and slope indexes of inequality with 95% confidence intervals (CIs). RESULTS: Singleton preterm live delivery proportion varied between 3.7% and 7.5%. There were large variations between the cohorts in the distribution of education and maternal characteristics. Nevertheless, there were similar educational differences in risk of preterm delivery in 8 of the 12 cohorts with slope index of inequality varying between 2.2 [95% CI 1.1, 3.3] and 4.0 [95% CI 1.4, 6.6] excess preterm deliveries per 100 singleton deliveries among the educationally most disadvantaged, and risk ratio between the lowest and highest education category varying from 1.4 [95% CI 1.1, 1.8] to 1.9 [95% CI 1.2, 3.1]. No associations were found in the last four cohorts. CONCLUSIONS: Educational disparities in preterm delivery were found all over Europe. Despite differences in the distributions of education and preterm delivery, the results were remarkably similar across the cohorts. For those few cohorts that did not follow the pattern, study and country characteristics did not explain the differences.
ISSN: 0269-5022

hal-01146842
https://hal-univ-rennes1.archives-ouvertes.fr/hal-01146842
DOI : 10.1111/ppe.12185
PUBMED : 25808200

Éditeur(s) : HAL CCSD
Résumé : International audience
o abstract
Revue Des Maladies Respiratoires

hal-01647076
https://hal-univ-rennes1.archives-ouvertes.fr/hal-01647076
DOI : 10.1016/j.rmr.2017.07.022
PUBMED : 28935495

Éditeur(s) : HAL CCSD Elsevier
Résumé : International audience
In this study, we propose a theoretical approach to test the validity of the isomechanical analogues for post-perovskite structures. Intrinsic plastic properties are evaluated for three materials exhibiting a post-perovskite phase: MgSiO3, MgGeO3 and CaIrO3. Dislocation properties of each structure are determined using the Peierls-Nabarro model based on first-principles calculations of generalised stacking fault and the plastic properties are extended to crystal-preferred orientations using a visco-plastic self-consistent method. This study provides intrinsic parameters of plastic deformation such as dislocation structures and Peierls stresses that can be directly compared between the three materials. It appears that it is very difficult to draw any simple conclusions on polycrystalline deformation simply by comparing single crystal properties. In particular, contrasting single crystal properties of MgSiO3 and CaIrO3 lead to similar crystal-preferred orientation of the polycrystal aggregates.
ISSN: 0031-9201

hal-00420104
https://hal.archives-ouvertes.fr/hal-00420104
DOI : 10.1016/j.pepi.2008.04.003

Éditeur(s) : HAL CCSD
Résumé : International audience
Women who drink light-to-moderately during pregnancy have been observed to have lower risk of unfavourable pregnancy outcomes than abstainers. This has been suggested to be a result of bias. In a pooled sample, including 193 747 live-born singletons from nine European cohorts, we examined the associations between light-to-moderate drinking and preterm birth, birth weight, and small-for-gestational age in term born children (term SGA). To address potential sources of bias, we compared the associations from the total sample with a sub-sample restricted to first-time pregnant women who conceived within six months of trying, and examined whether the associations varied across calendar time. In the total sample, drinking up to around six drinks per week as compared to abstaining was associated with lower risk of preterm birth, whereas no significant associations were found for birth weight or term SGA. Drinking six or more drinks per week was associated with lower birth weight and higher risk of term SGA, but no increased risk of preterm birth. The analyses restricted to women without reproductive experience revealed similar results. Before 2000 approximately half of pregnant women drank alcohol. This decreased to 39% in 2000–2004, and 14% in 2005–2011. Before 2000, every additional drink was associated with reduced mean birth weight, whereas in 2005–2011, the mean birth weight increased with increasing intake. The period-specific associations between low-to-moderate drinking and birth weight, which also were observed for term SGA, are indicative of bias. It is impossible to distinguish if the bias is attributable to unmeasured confounding, which change over time or cohort heterogeneity. © 2017, Springer Science+Business Media B.V.
ISSN: 03932990

hal-01647159
https://hal-univ-rennes1.archives-ouvertes.fr/hal-01647159
DOI : 10.1007/s10654-017-0323-2
PUBMED : 29027084

Éditeur(s) : HAL CCSD Wiley
Résumé : International audience
BACKGROUND: This study examines gene-environment interaction between the MTHFR C667T polymorphism and folic acid in the etiology of orofacial clefts (OFC). We used a pooled-analytical approach on four studies that used similar methods. METHODS: We used logistic regression to analyze the pooled sample of 1149 isolated cases and 1161 controls. Fetal and maternal MTHFR C677T genotypes, and maternal periconceptional exposure to smoking, alcohol, vitamin containing folic acid and folic acid supplements were contrasted between the cleft types [non-syndromic clefts lip or without cleft palate (CL(P)) and non-syndromic cleft palate (CP)] and control groups. RESULTS: There was a reduced risk of CL(P) with maternal folic acid use (p = 0.008; OR = 0.70, 95% CI: 0.65-0.94) and with supplements containing folic acid (p = 0.028, OR = 0.80, 95% CI: 0.65-0.94). Maternal smoking increased the risk of both CL(P) (p < 10 e-3; OR = 1.62, 95% CI: 1.35-1.95) and CP (p = 0.028; OR = 1.38, 95% CI: 1.04-1.83). No significant risk was observed with either maternal or fetal MTHFR C677T genotypes. CONCLUSION: This individual participant data (IPD) meta-analysis affords greater statistical power and can help alleviate the problems associated with aggregate-level data-sharing. The result of this IPD meta-analysis is consistent with previous reports suggesting that folic acid and smoking influence OFC outcomes.
ISSN: 1542-0752

hal-00875899
https://hal.archives-ouvertes.fr/hal-00875899
DOI : 10.1002/bdra.23133
PUBMED : 23670871

Éditeur(s) : HAL CCSD
Résumé : International audience
Objective To guide nosology and classification of patients with eosinophilic granulomatosis with polyangiitis (EGPA) based on phenotype and presence or absence of ANCA. Methods Organ manifestations and ANCA status were retrospectively analyzed based on the presence or not of predefined definite vasculitis features or surrogates of vasculitis in patients asthma, eosinophilia, and at least one systemic organ manifestation attributable to systemic disease. Results The study population included 157 patients (mean age 49.4 ± 14.1), with a follow-up of 7.4 ± 6.4 years. Patients with ANCA (31%) more frequently had weight loss, myalgias, arthralgias, biopsy-proven vasculitis, glomerulonephritis on biopsy, hematuria, leukocytoclastic capillaritis and/or eosinophilic infiltration of arterial wall on biopsy, and other renal disease. A total of 41% of patients had definite vasculitis manifestations (37%) or strong surrogates of vasculitis (4%), of whom only 53% had ANCA. Mononeuritis multiplex was associated with systemic vasculitis (p = 0.005) and with the presence of ANCA (p < 0.001). Overall, 59% of patients had polyangiitis as defined by definite vasculitis, strong surrogate of vasculitis, mononeuritis multiplex, and/or ANCA with at least one systemic manifestation other than ENT or respiratory. Patients with polyangiitis had more systemic manifestations including arthralgias (p = 0.02) and renal disease (p = 0.024), had higher peripheral eosinophilia (p = 0.027), and a trend towards less myocarditis (p = 0.057). Using predefined criteria of vasculitis and surrogates of vasculitis, ANCA alone were found to be insufficient to categorise patients with vasculitis features. Conclusion We suggest a revised nomenclature and definition for EGPA and a new proposed entity referred to as hypereosinophilic asthma with systemic (non vasculitic) manifestations. © 2016 Elsevier B.V.
Autoimmunity Reviews

hal-01467544
https://hal-univ-rennes1.archives-ouvertes.fr/hal-01467544
DOI : 10.1016/j.autrev.2016.09.018
PUBMED : 27671089

Éditeur(s) : HAL CCSD
Résumé : International audience
o abstract
Revue Des Maladies Respiratoires

hal-01647079
https://hal-univ-rennes1.archives-ouvertes.fr/hal-01647079
DOI : 10.1016/j.rmr.2017.07.019
PUBMED : 28939154

Éditeur(s) : HAL CCSD Oxford University Press (OUP)
Résumé : International audience
Two types of olivine occur in kimberlites from Greenland, Canada and southern Africa. The first, xenocrystic olivine, displays several different forms. Most distinctive are 'nodules', a term we use to describe the large (1-5 mm), rounded, single crystals or polycrystalline aggregates that are a common constituent of many kimberlites. Olivine compositions are uniform within single nodules but vary widely from nodule to nodule, from Fo81 to 93. Within many nodules, sub- to euhedral asymmetric tablets have grown within larger anhedral olivine grains. Dislocation structures, particularly in the anhedral grains, demonstrate that this olivine was deformed before being incorporated into the kimberlite magma. Olivine grains in the kimberlite matrix between the nodules have morphologies similar to those of the tablets, suggesting that most matrix olivine grains are parts of disaggregated nodules. We propose that a sub- to euhedral form is not sufficient to identify phenocrysts in kimberlites and provide some criteria, based on morphology, internal deformation and composition, that distinguish phenocrysts from xenocrysts. The second type of olivine is restricted to rims surrounding xenocrystic grains. Only this olivine crystallized from the kimberlite magma. Major and trace element data for the rim olivine are used to calculate the composition of the parental kimberlite liquid, which is found to contain between about 20 and 30% MgO. The bulk compositions of many kimberlites contain higher MgO contents as a result of the presence of xenocrystic olivine. The monomineralic, dunitic, character of the nodules, and the wide range from Fo-rich to Fo-poor olivine compositions, provide major constraints on the origin of the nodules. Dunite is a relatively rare rock in the mantle and where present its olivine is persistently Fo-rich. The dunitic source of the nodules in kimberlites lacked minerals such as pyroxene and an aluminous phase, which make up about half of most mantle-derived rocks. It appears that these minerals were removed from the mantle peridotite that was to become the source of the nodules, and the Fo content of the retained olivine was modified during interaction with CO2-rich fluids whose arrival at the base of the lithosphere immediately preceded the passage of the kimberlite magmas. Fragments of the resultant dunite were entrained into the kimberlite, where they were retained both as intact nodules and as disaggregated grains in the matrix.
ISSN: 0022-3530

insu-00543321
https://hal-insu.archives-ouvertes.fr/insu-00543321
BIBCODE : 10.1093/petrology/egp080
DOI : 10.1093/petrology/egp080

Éditeur(s) : HAL CCSD Elsevier
Résumé : We have studied the phase transformation of forsterite to wadsleyite under shear stress at the Earth's transition zone pressure and temperature conditions. Two-step experiments were performed using a multi-anvil press. First, we hot pressed iron-free forsterite at 6 or 11 GPa and 1100 degrees C. Then we deformed a slab of this starting material using a direct simple shear assembly at 16 GPa and 1400 degrees C for 1, 15, 35, 40, or 60 min. Both the starting material and the deformed samples were characterized using optical and scanning electron microscopy including measurements of crystal preferred orientations (CPO) by electron back scattered diffraction (EBSD), transmission electron microscopy (TEM), and Fourier transform infrared spectroscopy (FTIR). The phase transformation occurs very rapidly, in less than 1 min, and metastable forsterite relics are not observed after deformation. The grain size of wadsleyite is slightly smaller than the forsterite starting material. The water contents obtained from FTIR analyses in forsterite and wadsleyite are 65-124 wt ppm H2O and 114-736 wt ppm H2O, respectively, which are well below water solubility at similar conditions in the presence of free water. Wadsleyite aggregates display weak CPO patterns with [1 0 0] axes concentrated at low angle to the shear direction, [0 1 0] axes perpendicular to the shear plane and nearly random [0 0 1] axes. Only a few dislocations were observed in wadsleyite with TEM. This observation is consistent with the assumption that most dislocations formed during the initial high-stress stages of these stress-relaxation experiments, were consumed in the phase transformation, probably enhancing the transformation rate. CPO patterns vary as a function of the water content: with increasing water content the density of [1 0 0] axes parallel to the shear direction decreases, and the density of [0 0 1] axes increases. Viscoplastic self-consistent modeling of CPO evolution using previously reported glide systems for wadsleyite, i.e., [1 0 0]{0 k 1} and 1/2 (1 1 1){1 0 1}, cannot reproduce the measured CPO, unless the [0 0 1](0 1 0) system, for which dislocations have not been observed by TEM, is also activated. In addition, wadsleyite grain growth suggests the participation of diffusion-assisted processes in deformation. Calculated anisotropies for P and S-waves using measured CPO are always below 1%. This very low anisotropy is due to both the low finite strain achieved in the experiments, which leads to weak wadsleyite CPO, and to the diluting effect of added majorite. The present experiments emphasize the importance of stress, grain size evolution and water content in the forsterite to wadsleyite phase transformation and subsequent deformation in the transition zone.
ISSN: 0031-9201

hal-00617430
https://hal.archives-ouvertes.fr/hal-00617430
DOI : 10.1016/j.pepi.2010.11.001

Éditeur(s) : HAL CCSD European Respiratory Society
Résumé : International audience
Telomerase reverse transcriptase (TERT) or telomerase RNA (TERC) gene mutation is a major monogenic cause of pulmonary fibrosis. Sequencing of TERT/TERC genes is proposed to patients with familial pulmonary fibrosis. Little is known about the possible predictors of this mutation and its impact on prognosis. We retrospectively analysed all the genetic diagnoses made between 2007-2014 in patients with pulmonary fibrosis. We evaluated the prevalence of TERT/TERC disease-Associated variant (DAV), factors associated with a DAV, and the impact of the DAV on survival. 237 patients with pulmonary fibrosis (153 with familial pulmonary fibrosis, 84 with telomere syndrome features without familial pulmonary fibrosis) were tested for TERT/TERC DAV. DAV was diagnosed in 40 patients (16.8%), including five with non-idiopathic interstitial pneumonia. Prevalence of TERT/TERC DAV did not significantly differ between patients with familial pulmonary fibrosis or with only telomere syndrome features (18.2% versus 16.4%). Young age, red blood cell macrocytosis, and low platelet count were associated with the presence of DAV; the probability of DAV was increased for patients 40-60 years. Transplant-free survival was lower with than without TERT/TERC DAV (4.2 versus 7.2 years; p=0.046). TERT/TERC DAV were associated with specific clinical and biological features and reduced transplantfree survival. ©ERS 2016.
ISSN: 0903-1936

hal-01467555
https://hal-univ-rennes1.archives-ouvertes.fr/hal-01467555
https://hal-univ-rennes1.archives-ouvertes.fr/hal-01467555/document
https://hal-univ-rennes1.archives-ouvertes.fr/hal-01467555/file/Prevalence%20and%20characteristics%20of%20TERT.pdf
DOI : 10.1183/13993003.02115-2015

Éditeur(s) : HAL CCSD Springer Verlag
Résumé : International audience
There appears to be an incompressible high rate of preterm births among populations of African origin irrespective of their geographic location. The objective of this study was to assess the risk factors for preterm birth in a French Caribbean population of African descent, offered medical care comparable to that on the French mainland, but presenting a higher rate of preterm birth. The study was based on a birth cohort at maternity hospitals in Guadeloupe (French West Indies) including 911 singleton pregnancies enrolled during their third trimester check-up visits. Associations between risk factors and the risk of preterm delivery (spontaneous and induced) were assessed using a multivariate Cox model. In addition, prevalences of sociodemographic and medical factors in Guadeloupe were compared with those on the French mainland. 144 women (15.8 %) delivered preterm, medically induced in 52 %. Women delivering preterm were more often over 35 years old (37 %), single (54 %), and had higher prevalence of prior preterm birth (20 %), prior miscarriage (37 %), lupus (3 %), asthma (14 %), gestational hypertension (26 %), gestational diabetes (13 %) and urinary tract infection (24 %) than women with term births. In the whole cohort, these risk factors were also more frequent than in mainland France. Our results suggest highly prevalent medical risk factors for preterm births in Guadeloupe. This observation combined with specific social risk factors (older maternal age, single living) less frequent on the French mainland probably explains a large part of a higher prevalence of preterm births in this population despite similar medical provision.
ISSN: 1092-7875

hal-00860340
https://hal-univ-rennes1.archives-ouvertes.fr/hal-00860340
https://hal-univ-rennes1.archives-ouvertes.fr/hal-00860340/document
https://hal-univ-rennes1.archives-ouvertes.fr/hal-00860340/file/rouget_mat_child_health-accepted.pdf
DOI : 10.1007/s10995-012-1112-x

Éditeur(s) : HAL CCSD Endocrine Society
Résumé : International audience
The Developmental Origins of Health and Disease (DOHaD) paradigm is one of the most rapidly expanding areas of biomedical research. Environmental stressors that can impact on DOHaD encompass a variety of environmental and occupational hazards as well as deficiency and oversupply of nutrients and energy. They can disrupt early developmental processes and lead to increased susceptibility to disease/dysfunctions later in life. Presentations at the fourth Conference on Prenatal Programming and Toxicity in Boston, in October 2014, provided important insights and led to new recommendations for research and public health action. The conference highlighted vulnerable exposure windows that can occur as early as the preconception period and epigenetics as a major mechanism than can lead to disadvantageous "reprogramming" of the genome, thereby potentially resulting in transgenerational effects. Stem cells can also be targets of environmental stressors, thus paving another way for effects that may last a lifetime. Current testing paradigms do not allow proper characterization of risk factors and their interactions. Thus, relevant exposure levels and combinations for testing must be identified from human exposure situations and outcome assessments. Testing of potential underpinning mechanisms and biomarker development require laboratory animal models and in vitro approaches. Only few large-scale birth cohorts exist, and collaboration between birth cohorts on a global scale should be facilitated. DOHaD-based research has a crucial role in establishing factors leading to detrimental outcomes and developing early preventative/remediation strategies to combat these risks
ISSN: 0013-7227

hal-01187409
https://hal-univ-rennes1.archives-ouvertes.fr/hal-01187409
DOI : 10.1210/EN.2015-1350
PUBMED : 26241067

Éditeur(s) : HAL CCSD Elsevier Masson
Résumé : CCBY
National audience
ISSN: 0761-8425

hal-01117879
https://hal-univ-rennes1.archives-ouvertes.fr/hal-01117879
PUBMED : 24314711
DOI : 10.1016/j.rmr.2013.09.007

Éditeur(s) : HAL CCSD
Résumé : International audience
BACKGROUND: There is no recommendation for treating pulmonary hypertension (PH) when associated with chronic obstructive pulmonary disease (COPD). OBJECTIVE: To evaluate the effect of PH-specific therapy in patients with COPD. METHODS: All successive patients with severe PH [mean pulmonary arterial pressure (mPAP) ≥35 mm Hg] and COPD, who received specific PH medication and who underwent right heart catheterization at baseline and after 3-12 months of treatment, were analyzed from a prospective database. RESULTS: Twenty-six patients were included with a median follow-up of 14 months. Mean forced expiratory volume in 1 s was 57 ± 20% of predicted, and mean forced expiratory volume in 1 s/forced vital capacity was 47 ± 12%. Dyspnea was New York Health Association classification stage (NYHA) II in 15%, NYHA III in 81% and NYHA IV in 4%. First-line treatments were endothelin receptor antagonists in 11 patients, phosphodiesterase-5 inhibitors in 11 patients, calcium blocker in 1 patient, combination therapy in 3 patients including 2 with a prostanoid. After 6 ± 3 months, pulmonary vascular resistance decreased from 8.5 ± 3 to 6.6 ± 2 Wood units (p extless 0.001), with significant improvement of cardiac index from 2.44 ± 0.43 to 2.68 ± 0.63 liters × min × m-2 (p = 0.015) and mPAP from 48 ± 9 to 42 ± 10 mm Hg (p = 0.008). There was no significant difference in dyspnea, 6-min walking distance, echocardiographic parameters or N-terminal pro-brain natriuretic peptide levels. There was no significant difference in arterial oxygen saturation after 3-12 months of treatment. CONCLUSIONS: Specific PH medications may improve hemodynamic parameters in COPD patients with severe PH. Appropriate prospective randomized studies are needed to evaluate the potential long-term clinical benefit of treatment
Respiration; International Review of Thoracic Diseases

hal-01239807
https://hal-univ-rennes1.archives-ouvertes.fr/hal-01239807
DOI : 10.1159/000431380
PUBMED : 26277885

Éditeur(s) : HAL CCSD Elsevier
Résumé : International audience
In order to estimate the seismic anisotropy of subducted crust, polycrystalline samples of KA1Si(3)O(8) K-lingunite (25% of the total subducted transformed sediments), have been synthesized and deformed under the temperature and pressure conditions of the subducted slabs. Transmission electron microscopy (TEM) characterizations of the recovered samples reveal that the microstructures are clearly dominated by [001] glide involving screw dislocations. For this reason, only {100} could be identified as glide planes, the question of [001] slip on {110} remains open. Few 1/2 < 111 > dislocations were observed gliding on {110} planes, which implies that 1/2 < 111 > {110} is a harder slip system than those involving [001] slip. The occurrence of sub-grain boundaries suggests that diffusion and climb might be active under these conditions.;To assess the texture of polycrystalline K-lingunite, the crystal preferred orientations (CP05) were calculated using visco-plastic self-consistent (VPSC) polycrystalline plasticity model in simple shear using the slip systems identified by TEM. Finally, the seismic properties of K-lingunite aggregates were calculated from the CPO and single crystal elasticity tensor. K-lingunite is predicted to have a high seismic anisotropy, which could combine constructively with one of the stishovite (same proportion as K-lingunite at the transition zone depth ranges).
ISSN: 0031-9201

hal-00534050
https://hal.archives-ouvertes.fr/hal-00534050
DOI : 10.1016/j.pepi.2010.06.013