Intérêt de la Gabapentine et de la Mirtazapine dans la reprise de l’alimentation en période post-opératoire chez le chat sain : synthèse bibliographique et étude clinique

L'auteur présente une étude clinique évaluant le pouvoir orexigène de la Gabapentine et de la Mirtazapine chez le chat. Il propose d'en comparer les effets lorsque ces molécules sont administrées par voie orale à des jeunes chattes subissant une ovariectomie. La prise alimentaire et la douleur sont suivies en post-opératoire immédiat puis pendant une journée chez le propriétaire de l'animal à l'aide d'une enquête téléphonique. Deux groupes d'animaux sont établis, Gabapentine ou Mirtazapine ; un troisième groupe de référence (groupe placebo) est mis en place afin d'évaluer la pertinence de ces molécules. La Gabapentine et la Mirtazapine augmentent de manière très significative la propension des chattes à s'alimenter et la quantité d'aliment ingérée dans les heures qui suivent leur réveil de l'intervention chirurgicale

Functional evaluation of anterior cruciate ligagment autografts in pre-clinical animal models

Introduction Rupture of the Anterior Cruciate Ligament (ACL) affects about 1 person over 3000 every year. The current standard care is based on ligament reconstruction by autograft from tendon tissues and is considered as the gold standard. Yet, autograft reconstruction presents serious limitations. Recent developments in artificial ligaments are promising and could potentially address the currently growing demand from surgeons and patients for an off-the-shelf alternate solution. However, before these can be commonly used in clinical routine, their biocompatibility and biomechanical performance for the short and long terms must be studied in pre-clinical animal models. Building upon the work of [1], we propose in this contribution a methodology for assessing the biomechanical performance of artificial ligaments, and to provide reference data (autografts) using an animal model (sheep) at 3 months after implantation. Materials and Methods Surgery and specimen preparation 14 fresh frozen lower limbs were used in this study, seven left (autograft implantation) and seven right (contralateral) knees. These were harvested from seven sheep sacrificed 3 months after implantation. The biomechanical analysis of the knees consisted of four successive in vitro experiments: three kinematics tests (flexion-extension, varus-valgus laxity and anterior drawer tests) and a pull-out destructive test. Kinematics analysis: flexion-extension and laxity tests The kinematic analysis was performed using specific motorized devices adapted from previously described and validated ones [1]. The protocol combined motion analysis of tripods screwed in the bony structures and 3D personalized reconstruction (figure 1) from low-dose X-ray system (EOS, EOS Imaging, Paris, France) [1,2,3,4]. Pull-out destructive tests The pull-out tests were performed using an INSTRON 5566 testing machine (Instron Ltd., Buckingham-shire, England) instrumented with a 5 kN load cell. After conditioning, a tension load was applied to the specimen (5 mm/min) until total failure. Data analysis: mobility assessment and statistical tests The following parameters were extracted to allow the comparison with the literature [1] (i) Internal rotation Ry (°) value for a 40° flexion angle (Ry_40), (ii) Anterior Tibial Translation (mm) for 100 N loading (ATT_100), (iii) Varus Valgus amplitude (°) at 4 Nm loading (VV_4) and (iv) the Failure load (N) (FL). Results and discussion The results shows a good consistency for kinematic parameters of the contralateral knees. The failure load was clearly different due to the interindividual variability. As concerns the autograft, a reduction of internal rotation during the flexion motion and an increase of the laxity in ATT could be observed. The failure load was also decreased for the grafted knee.This work was supported by the French National Research Agency (ANR project n°ANR-08-ETEC-003

Examining wheat yield sensitivity to temperature and precipitation changes for a large ensemble of crop models using impact response surfaces

Impact response surfaces (IRSs) depict the response of an impact variable to changes in two explanatory variables as a plotted surface. Here, IRSs of spring and winter wheat yields were constructed from a 25-member ensemble of process-based crop simulation models. Twenty-one models were calibrated by different groups using a common set of calibration data, with calibrations applied independently to the same models in three cases. The sensitivity of modelled yield to changes in temperature and precipitation was tested by systematically modifying values of 1981-2010 baseline weather data to span the range of 19 changes projected for the late 21st century at three locations in Europe

An ensemble of projections of wheat adaptation to climate change in europe analyzed with impact response surfaces

IRS2 TEAM:Alfredo Rodríguez(1), Ignacio J. Lorite(3), Fulu Tao(4), Nina Pirttioja(5), Stefan Fronzek(5), Taru Palosuo(4), Timothy R. Carter(5), Marco Bindi(2), Jukka G Höhn(4), Kurt Christian Kersebaum(6), Miroslav Trnka(7,8),Holger Hoffmann(9), Piotr Baranowski(10), Samuel Buis(11), Davide Cammarano(12), Yi Chen(13,4), Paola Deligios(14), Petr Hlavinka(7,8), Frantisek Jurecka(7,8), Jaromir Krzyszczak(10), Marcos Lana(6), Julien Minet(15), Manuel Montesino(16), Claas Nendel(6), John Porter(16), Jaime Recio(1), Françoise Ruget(11), Alberto Sanz(1), Zacharias Steinmetz(17,18), Pierre Stratonovitch(19), Iwan Supit(20), Domenico Ventrella(21), Allard de Wit(20) and Reimund P. Rötter(4).An ensemble of projections of wheat adaptation to climate change in europe analyzed with impact response surfaces . International Crop Modelling Symposiu

Applying adaptation response surfaces for managing wheat under perturbed climate and elevated CO2 in a Mediterranean environment

This study developed Adaptation Response Surfaces and applied them to a study case in North East Spain on winter crops adaptation, using rainfed winter wheat as reference crop.  Crop responses to perturbed temperature, precipitation and CO2 were simulated by an ensemble of crop models. A set of combined changes on cultivars (on vernalisation requirements and phenology) and management (on sowing date and irrigation) were considered as adaptation options and simulated by the crop model ensemble. The discussion focused on two main issues: 1) the recommended adaptation options for different soil types and perturbation levels, and 2) the need of applying our current knowledge (AOCK) when building a crop model ensemble. The study has been published Agricultural Systems (Available online 25 January 2017, https://doi.org/10.1016/j.agsy.2017.01.009), and the  text below consists on extracts from that paper

A wear model to predict the damage of ACL implants

International audienc

A wear model to predict damage of reconstructed ACL

International audienc

A wear model to predict damage of reconstructed ACL

International audienc

A wear model to predict damage of reconstructed ACL

Impingement with surrounding tissues is a major cause of failure of anterior cruciate ligament reconstruction. However, the complexity of the knee kinematics and anatomical variations make it difficult to predict the occurrence of contact and the extent of the resulting damage. Here we hypothesise that a description of wear between the reconstructed ligament and adjacent structures captures the in vivo damage produced with physiological loadings. To test this, we performed an in vivo study on a sheep model and investigated the role of different sources of damage: overstretching, excessive twist, excessive compression, and wear. Seven sheep underwent cranial cruciate ligament reconstruction using a tendon autograft. Necropsy observations and pull-out force measurements performed postoperatively at three months showed high variability across specimens of the extent and location of graft damage. Using 3D digital models of each stifle based on X-ray imaging and kinematics measurements, we determined the relative displacements between the graft and the surrounding bones and computed a wear index describing the work of friction forces underwent by the graft during a full flexion-extension movement. While tensile strain, angle of twist and impingement volume showed no correlation with pull-out force (ρ = −0.321, p = 0.498), the wear index showed a strong negative correlation (r = −0.902, p = 0.006). Moreover, contour maps showing the distribution of wear on the graft were consistent with the observations of damage during the necropsy. These results demonstrate that wear is a good proxy of graft damage. The proposed wear index could be used in implant design and surgery planning to minimise the risk of implant failure. Its application to sheep can provide a way to increase preclinical testing efficiency

Selective and reversible disruption of mitochondrial inner membrane protein complexes by lipophilic cations

Triphenylphosphonium (TPP) derivatives are commonly used to target chemical into mitochondria. We show that alkyl-TPP cause reversible, dose- and hydrophobicity-dependent alterations of mitochondrial morphology and function and a selective decrease of mitochondrial inner membrane proteins including subunits of the respiratory chain complexes, as well as components of the mitochondrial calcium uniporter complex. The treatment with alkyl-TPP resulted in the cleavage of the pro-fusion and cristae organisation regulator Optic atrophy-1. The structural and functional effects of alkyl-TPP were found to be reversible and not merely due to loss of membrane potential. A similar effect was observed with the mitochondria-targeted antioxidant MitoQ