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Showing papers by "Université Nantes Angers Le Mans published in 2018"


Journal ArticleDOI
TL;DR: The study shows that ibuprofen use results in selective transcriptional repression of endocrine cells in the human testis, resulting in a state of compensated hypogonadism, a disorder associated with adverse reproductive and physical health disorders.
Abstract: Concern has been raised over increased male reproductive disorders in the Western world, and the disruption of male endocrinology has been suggested to play a central role. Several studies have shown that mild analgesics exposure during fetal life is associated with antiandrogenic effects and congenital malformations, but the effects on the adult man remain largely unknown. Through a clinical trial with young men exposed to ibuprofen, we show that the analgesic resulted in the clinical condition named "compensated hypogonadism," a condition prevalent among elderly men and associated with reproductive and physical disorders. In the men, luteinizing hormone (LH) and ibuprofen plasma levels were positively correlated, and the testosterone/LH ratio decreased. Using adult testis explants exposed or not exposed to ibuprofen, we demonstrate that the endocrine capabilities from testicular Leydig and Sertoli cells, including testosterone production, were suppressed through transcriptional repression. This effect was also observed in a human steroidogenic cell line. Our data demonstrate that ibuprofen alters the endocrine system via selective transcriptional repression in the human testes, thereby inducing compensated hypogonadism.

84 citations


Journal ArticleDOI
TL;DR: This paper relies on vehicle trajectory collection on a corridor, to compare different traffic representations used for the estimation of the sound power of light vehicles and the resulting sound pressure levels and significant differences within the models are highlighted.
Abstract: This paper relies on vehicle trajectory collection on a corridor, to compare different traffic representations used for the estimation of the sound power of light vehicles and the resulting sound pressure levels. Four noise emission models are tested. The error introduced when the emissions are calculated based on speeds measured at regular intervals along the road network are quantified and explained. The current noise emission models might in particular misestimate noise levels under congestion. This bias can be reduced by introducing additional traffic variables in the modeling. In addition, significant differences within the models are highlighted, especially concerning their accounting of vehicle accelerations. Models that rely on a binary representation of acceleration regimes (a vehicle or a road segment is accelerating or not) can lead to errors in practice. Models under use in Europe have a very low sensitivity to acceleration values. These results help underlying the further required improvements of dynamic road traffic noise models.

57 citations


Journal ArticleDOI
TL;DR: The ability of breast-milk lipid species to predict early-growth was validated in presence of confounding clinical factors but remains to be ascertained in larger cohort studies.
Abstract: Human milk is recommended for feeding preterm infants. The current pilot study aims to determine whether breast-milk lipidome had any impact on the early growth-pattern of preterm infants fed their own mother's milk. A prospective-monocentric-observational birth-cohort was established, enrolling 138 preterm infants, who received their own mother's breast-milk throughout hospital stay. All infants were ranked according to the change in weight Z-score between birth and hospital discharge. Then, we selected infants who experienced "slower" (n = 15, -1.54 ± 0.42 Z-score) or "faster" (n = 11, -0.48 ± 0.19 Z-score) growth; as expected, although groups did not differ regarding gestational age, birth weight Z-score was lower in the "faster-growth" group (0.56 ± 0.72 vs. -1.59 ± 0.96). Liquid chromatography-mass spectrometry lipidomic signatures combined with multivariate analyses made it possible to identify breast-milk lipid species that allowed clear-cut discrimination between groups. Validation of the selected biomarkers was performed using multidimensional statistical, false-discovery-rate and ROC (Receiver Operating Characteristic) tools. Breast-milk associated with faster growth contained more medium-chain saturated fatty acid and sphingomyelin, dihomo-γ-linolenic acid (DGLA)-containing phosphethanolamine, and less oleic acid-containing triglyceride and DGLA-oxylipin. The ability of such biomarkers to predict early-growth was validated in presence of confounding clinical factors but remains to be ascertained in larger cohort studies.

45 citations


Journal ArticleDOI
TL;DR: In this paper, the influence of kenaf fiber length on the mechanical and thermal properties of compressed earth blocks (CEB) was evaluated and the results showed that the real possibility to improve CEB mechanical properties by using fibers for reinforcement.
Abstract: The association of natural fibers and raw land soil has many advantages (thermal control, sound insulation, mechanical behavior, etc.). However, the major issue with the use of these materials is the lack of knowledge regarding their reliability and durability. In this work, we have evaluated the influence of kenaf fiber length on the mechanical and thermal properties of compressed earth blocks (CEB). Fibers with length 10, 20 or 30 mm were used at mixing rate of 1.2% dry weight of soil; with the aim to enhance the mechanical and thermal properties of CEB fabricated starting from a plastic clayey soil mined in Benin. Analysis of the mechanical behavior of different Soil/Fiber formulations in terms of flexural strength demonstrated the beneficial effect of the fibers. However, the mechanical strength of CEB obtained by immersing fibers till saturation prior to incorporation into the soil greatly diminished. The higher flexural strength was obtained with fibers 30 mm long. The thermal conductivity of CEB decreased when the fiber length was raised. The results showed the real possibility to improve CEB mechanical and thermal properties by using fibers for reinforcement.

28 citations


Journal ArticleDOI
TL;DR: This model highlights the role of KIF1C protein in preserving the structural integrity and function of myelin, since the clinical signs and lesions arise in young-adult Charolais cattle, and provides useful information for SPG58/SPAX2 disease and other demyelinating lesions.
Abstract: Hereditary spastic paraplegias (HSPs) are clinically and genetically heterogeneous human neurodegenerative diseases. Amongst the identified genetic causes, mutations in genes encoding motor proteins such as kinesins have been involved in various HSP clinical isoforms. Mutations in KIF1C are responsible for autosomal recessive spastic paraplegia type 58 (SPG58) and spastic ataxia 2 (SPAX2). Bovines also develop neurodegenerative diseases, some of them having a genetic aetiology. Bovine progressive ataxia was first described in the Charolais breed in the early 1970s in England and further cases in this breed were subsequently reported worldwide. We can now report that progressive ataxia of Charolais cattle results from a homozygous single nucleotide polymorphism in the coding region of the KIF1C gene. In this study, we show that the mutation at the heterozygous state is associated with a better score for muscular development, explaining its balancing selection for several decades, and the resulting high frequency (13%) of the allele in the French Charolais breed. We demonstrate that the KIF1C bovine mutation leads to a functional knock-out, therefore mimicking mutations in humans affected by SPG58/SPAX2. The functional consequences of KIF1C loss of function in cattle were also histologically reevaluated. We showed by an immunochemistry approach that demyelinating plaques were due to altered oligodendrocyte membrane protrusion, and we highlight an abnormal accumulation of actin in the core of demyelinating plaques, which is normally concentrated at the leading edge of oligodendrocytes during axon wrapping. We also observed that the lesions were associated with abnormal extension of paranodal sections. Moreover, this model highlights the role of KIF1C protein in preserving the structural integrity and function of myelin, since the clinical signs and lesions arise in young-adult Charolais cattle. Finally, this model provides useful information for SPG58/SPAX2 disease and other demyelinating lesions.

28 citations


Journal ArticleDOI
TL;DR: In this article, the authors investigated the printability conditions of a copolyester-based polymer that has not received yet much attention, and showed that the mechanical behavior of printed copolyesters is significantly affected by the filament arrangement within the meso-structure.

19 citations


Journal ArticleDOI
TL;DR: In this article, a multiobjective optimization procedure is employed to retrieve the viscoelatic parameters of silica aerogel clamped plates, which preserves the sample integrity and relies on the minimization of two different cost functions.
Abstract: A multiobjective optimization procedure is employed to retrieve the viscoelatic parameters of silica aerogel clamped plates. This retrieval method preserves the aerogel sample integrity and, in contrast to the existing ones, relies on the minimization of two different cost functions. The first one, namely J1, is related to the reflective properties of clamped plates backed by a rigid cavity, while the second one, namely J2, concerns both the reflectance and transmittance spectra measured in transmission configuration. The recovered parameters are in agreement with previously reported values in the literature. In addition, they are also supported by designing structures for perfect absorption (100% of absorption), which has been validated experimentally. Aerogel plates can be therefore used as innovative building units of artificial structures for the broadband absorption of sound.

11 citations


Journal ArticleDOI
TL;DR: In this paper, the gamma radiation was used for the synthesis of platinum nanoparticles by gamma irradiation at a dose of 70, 90 and 120 kGy, and the size of the nanoparticles was found to be 7.39 nm.
Abstract: The synthesis of Platinum (Pt) nanoparticles by gamma irradiation is presented. The 0.1 M Pt solution of different concentration was prepared from K2PtCl4. The platinum aqueous solutions were irradiated by gamma radiation at a dose of 70, 90 and 120 kGy. The findings show the effect of irradiation on PtII solutions with different concentrations. The big black particles that are fairly agglomerated when the concentration was above 0.0050 M were observed. The UV-Vis spectrum of Pt of different concentrations shows a strong absorption peak at the wavelength 261 nm after irradiation, which indicates the presence of platinum nanoparticles. Furthermore, FTIR, XRD and HRTEM images also confirmed the presence of the nanoparticles produced by Radiolysis. The size of the Pt nanoparticles was found to be 7.39 nm.

10 citations


Journal ArticleDOI
TL;DR: Bayesian inference results obtained from the proposed modeling extension for the description of wave propagation in porous media at low-mid frequencies suggest that the two additional parameters described by two parameters α 1 and α 2 are accessible and help reduce systematic errors in the identification of other parameters.
Abstract: In this article, a modeling extension for the description of wave propagation in porous media at low-mid frequencies is introduced. To better characterize the viscous and inertial interactions between the fluid and the structure in this regime, two additional terms described by two parameters α1 and α2 are taken into account in the representation of the dynamic tortuosity in a Laurent-series on frequency. The model limitations are discussed. A sensitivity analysis is performed, showing that the influence of α1 and α2 on the acoustic response of porous media is significant. A general Bayesian inference is then conducted to infer, simultaneously, the posterior probability densities of the model parameters. The proposed method is based on the measurement of waves transmitted by a slab of rigid porous material, using a temporal model for the direct and inverse transmission problem. Bayesian inference results obtained on three different porous materials are presented, which suggests that the two additional parameters are accessible and help reduce systematic errors in the identification of other parameters: porosity, static viscous permeability, static viscous tortuosity, static thermal permeability, and static thermal tortuosity.

10 citations


Journal ArticleDOI
TL;DR: Danish Headache Center, Department of Neurology, Rigshospitalet, University of Copenhagen, 1165 Copenhagen, Denmark; Université de Rennes I, Inserm, EHESP-School of Public Health, Irset, UMR_S 1085, F-35000 Rennes, France.
Abstract: Danish Headache Center, Department of Neurology, Rigshospitalet, University of Copenhagen, 1165 Copenhagen, Denmark; Université de Rennes I, Inserm, EHESP-School of Public Health, Irset (Institut de Recherche en Santé, Environnement et Travail) UMR_S 1085, F-35000 Rennes, France; Novo Nordisk Foundation Center for Protein Research Faculty of Health and Medical Sciences, University of Copenhagen, Blegdamsvej 3A, 2200 Copenhagen, Denmark; Institute of Sports Medicine, Department of Orthopaedic Surgery M, Bispebjerg Hospital, 2400 Copenhagen NV, Denmark; Center for Healthy Aging, Department of Biomedical Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, 1165 Copenhagen, Denmark; DTU Bio and Health Informatics, Technical University of Denmark, 2800 Kongens Lyngby, Denmark; Department of Pharmacy, Faculty of Health and Medical Sciences, University of Copenhagen, 1165 Copenhagen, Denmark; L’Université Nantes Angers Le Mans (LUNAM), Oniris, UMR 1329 INRA Laboratoire d’Etude des Résidus et Contaminants dans les Aliments (LABERCA), F-44307 Nantes, France; Unité de coordination hospitalière des prélèvements d’organes et de tissus, Centre Hospitalier Universitaire de Rennes, 35000 Rennes, France; Department of Odontology, Faculty of Health and Medical Sciences, University of Copenhagen, 1165 Copenhagen, Denmark; Department of Environmental Medicine, University of Southern Denmark, 5000 Odense, Denmark; Department of Biology, Faculty of Science, University of Copenhagen, 2100 Copenhagen, Denmark; Institute of Metagenomics, BGI-Shenzhen, Shenzhen 518083, China; Department of Growth and Reproduction, Rigshospitalet, University of Copenhagen, DK-2200 Copenhagen, Denmark; and EDMaRC (International Center for Research and Research Training in Endocrine Disruption of Male Reproduction and Child Health), Rigshospitalet, University of Copenhagen, DK-2200 Copenhagen, Denmark

9 citations


Journal ArticleDOI
TL;DR: Posterior tibial nerve stimulation was safe in a perioperative setting and had a potential effect on GI motility recovery, and will be useful for sample size calculations in a larger prospective randomized trial.
Abstract: Background Postoperative ileus involves an inflammatory pathway characterized by an increase of inflammation mediators in the colon wall; this could probably be prevented by sacral nerve neuromodulation. The posterior tibial nerve can be stimulated electrically to mimic neuromodulation. Objective The aims of this study were to assess the efficacy of transcutaneous posterior tibial nerve stimulation in reducing the delay in GI motility recovery, to assess the safety of posterior tibial nerve stimulation in a perioperative setting, and to assess the efficacy of posterior tibial nerve stimulation in reducing the occurrence of postoperative ileus. Design This was a preliminary randomized controlled study. Settings This study was conducted in 1 academic hospital in France. Patients Forty patients undergoing an elective colectomy were included and randomly assigned into 2 groups, posterior tibial nerve stimulation or placebo, according to the side of colectomy and the surgical access size. Intervention Perioperative posterior tibial nerve stimulation or placebo was performed 3 times per day according to the randomly assigned group. Main outcome measures Delay in GI motility recovery (passage of stool and tolerance of solid food) was measured. Results Of the 40 patients included, 34 were included in the final analysis, in which 2 patients in the placebo group were allocated the incorrect device. The 6 other patients were secondarily excluded because of protocol deviation. In the intention-to-treat analysis, the mean delay in GI motility recovery was 3.6 and 3.11 days (in the placebo and tibial nerve stimulation groups; p = 0.60). Occurrence of postoperative ileus was not significantly higher in the placebo group (35.3% vs 17.6%; p = 0.42). In the per-protocol analysis, we observed the same trends except for the occurrence of postoperative ileus, which was significantly higher in the placebo group (p = 0.045). Tolerance to posterior tibial nerve stimulation was good, and all of the patients completed the protocol. Limitations The amplitude of stimulation is set according to patient sensation, so some patients could have been aware of their group. In addition there were some inherent limitations because of the preliminary nature of the study and several deviations from the protocol. Conclusions Posterior tibial nerve stimulation was safe in a perioperative setting and had a potential effect on GI motility recovery. The results of this study will be useful for sample size calculations in a larger prospective randomized trial. See Video Abstract at http://links.lww.com/DCR/A708.

Journal ArticleDOI
TL;DR: The findings provide novel insights into OPG in regulation of CD34+ progenitor cells and give new opportunities for ex vivo expansion of human ECFCs using OPG as a cell culture component for future ECFC product manufacture according to GMP.
Abstract: Endothelial progenitor cells (EPCs) are the main hypothetical cells that could give rise to vessels and in particular one subtype isolated from peripheral or cord bloods: endothelial colony forming cells (ECFCs). These ECFCs are clonogenic precursors committed to endothelial lineage and have robust vasculogenic properties. However, their low number and poor expansion properties when isolated from human adult bloods, currently limit their use as an autologous cell therapy product. We previously reported that osteoprotegerin (OPG), a well-characterized regulator of bone metabolism, contributes to ischemic tissue revascularization, tumor growth in vivo, and potentiates ECFCs proangiogenic properties through the secretion of SDF-1. The current study investigated the role of OPG in ECFCs differentiation and expansion from cord blood CD34+ cells. OPG increased the number of ECFCs after endothelial differentiation of CD34+ cells, enhancing the time of EPCs colonies initial appearance and the growth kinetic of endothelial cell progeny. OPG-exposed ECFCs expressed higher levels of CD34+ compared to control ECFCs. In conclusion, our findings provide novel insights into OPG in regulation of CD34+ progenitor cells. These results give new opportunities for ex vivo expansion of human ECFCs using OPG as a cell culture component for future ECFC product manufacture according to GMP.

Journal ArticleDOI
TL;DR: The study found poor interest about work environment and that the cooperation between practitioners in disability management remains limited and the various practitioners’ cultures and interests may be a brake on cooperation and exchange of information.
Abstract: The objective of this study was to assess the workplace information collected and shared between professionals of the centers and occupational health professionals during functional restoration programs intended to chronic low back pain patients. A descriptive study carried out by a questionnaire sent to the French rehabilitation centers offering a functional restoration program. Data collection focused on the kinds of professionals involved in programs, professionals who approach work issues, work analysis, social and occupational information collected, existence of a specific work rehabilitation program, frequency of and methods for sharing information with occupational health professionals. Occupational information was mostly collected at inclusion during an individual interview by the rehabilitation physicians, social workers, and occupational therapists. Workplace environment was the most poorly discussed aspect. A minority of centers adapted their programs regarding these information. Information sharing with occupational physicians was mostly through the patient and was influenced by the presence of an ergonomist or of an occupational physician in the team. The study found poor interest about work environment and that the cooperation between practitioners in disability management remains limited. The various practitioners' cultures and interests may be a brake on cooperation and exchange of information.