Module-based multiscale simulation of angiogenesis in skeletal muscle

<p>Abstract</p> <p>Background</p> <p>Mathematical modeling of angiogenesis has been gaining momentum as a means to shed new light on the biological complexity underlying blood vessel growth. A variety of computational models have been developed, each focusing on different aspects of the angiogenesis process and occurring at different biological scales, ranging from the molecular to the tissue levels. Integration of models at different scales is a challenging and currently unsolved problem.</p> <p>Results</p> <p>We present an object-oriented module-based computational integration strategy to build a multiscale model of angiogenesis that links currently available models. As an example case, we use this approach to integrate modules representing microvascular blood flow, oxygen transport, vascular endothelial growth factor transport and endothelial cell behavior (sensing, migration and proliferation). Modeling methodologies in these modules include algebraic equations, partial differential equations and agent-based models with complex logical rules. We apply this integrated model to simulate exercise-induced angiogenesis in skeletal muscle. The simulation results compare capillary growth patterns between different exercise conditions for a single bout of exercise. Results demonstrate how the computational infrastructure can effectively integrate multiple modules by coordinating their connectivity and data exchange. Model parameterization offers simulation flexibility and a platform for performing sensitivity analysis.</p> <p>Conclusions</p> <p>This systems biology strategy can be applied to larger scale integration of computational models of angiogenesis in skeletal muscle, or other complex processes in other tissues under physiological and pathological conditions.</p

Functional outcomes in symptomatic versus asymptomatic patients undergoing incisional hernia repair: Replacing one problem with another? A prospective cohort study in 1312 patients

Background: Incisional hernias can be associated with pain or discomfort. Surgical repair especially mesh reinforcement, may likewise induce pain. The primary objective was to assess the incidence of pain after hernia repair in patients with and without pre-operative pain or discomfort. The secondary objectives were to determine the preferred mesh type, mesh location and surgical technique in minimizing postoperative pain or discomfort. Materials and methods: A registry-based prospective cohort study was performed, including patients undergoing incisional hernia repair between September 2011 and May 2019. Patients with a minimum follow-up of 3–6 months were included. The incidence of hernia related pain and discomfort was recorded perioperatively. Results: A total of 1312 patients were included. Pre-operatively, 1091 (83%) patients reported pain or discomfort. After hernia repair, 961 (73%) patients did not report pain or discomfort (mean follow-up = 11.1 months). Of the pre-operative asymptomatic patients (n = 221), 44 (20%, moderate or severe pain: n = 14, 32%) reported pain or discomfort after mean follow-up of 10.5 months. Of those patients initially reporting pain or discomfort (n = 1091), 307 (28%, moderate or severe pain: n = 80, 26%) still reported pain or discomfort after a mean follow-up of 11.3 months postoperatively. Conclusion: In symptomatic incisional hernia patients, hernia related complaints may be resolved in the majority of cases undergoing surgical repair. In asymptomatic incisional hernia patients, pain or discomfort may be induced in a considerable number of patients due to surgical repair and one should be aware if this postoperative complication

Modification de la forme d'arcade dans les cas de fentes labio-alvéolaires palatines unilatérales : application du logiciel «Arcad'image»

L'objectif de cette étude est d'analyser l'évolution et la variation de la forme d'arcade avant et après traitement, chez des patients porteurs de fentes labio-alvéolaires palatines unilatérales. L'échantillon est constitué d'une trentaine de patient, opérés par le même chirurgien et traités dans trois cabinets d'orthodontie utilisant la même technique. Les arcades maxillaires et mandibulaires, de début et de fin de traitement, sont scannées puis analysées par le logiciel "arcad'image". La méthode de modélisation utilisée est la méthode de régression robuste LTS (procédé mathématique permettant la construction de la courbe générale de l'arcade en atténuant l'influence des dents malpositionnées par rapport à la forme générale de l'arcade). Les résultats analysés à l'aide du laboratoire de statistique de l'UPS de Toulouse, permettent de mettre en évidence que, même avec un état initial peu favorable, une homogénéisation des formes d'arcades de l'échantillon après traitement est possible. On note cependant, après le traitement, une diminution de la longueur d'arcade, un aplatissement du secteur antérieur pour le maxillaire et peu de modification de la divergence des secteurs postérieurs. L'orthodontie des patients atteints de fentes labio-alvéolo-palatines a longtemps été un traitement de compromis, mais de nos jours, avec l'évolution des techniques et des matériaux, il est possible d'obtenir des résultats reproductibles et identiques aux patients ne présentant pas de fentes

Electrokinetic leakage as a tool to probe internal fouling in MF and UF membranes

International audienceTangential electrokinetic measurements are widely used to characterize membrane fouling as the membrane zeta potential is partly governed by the presence of foulant materials on its surface. However, in the case of porous materials as micro- (MF) and ultrafiltration (UF) membranes, a part of the streaming current flows through the porosity of the membrane during measurements. This electrokinetic leakage, is directly impacted by the presence of foulant materials inside the membrane porosity. Hence, this paper investigates for the first time the possibility of using electrokinetic leakage as a probe for detecting internal fouling, taking lipid fouling as example. Firstly, a lab-scale methodology combining "upside-down" fouling experiments with electrokinetic measurements demonstrated that the intensity of the electrokinetic leakage was related to the presence of internal fouling. Secondly, the concept was applied to the pilot-scale MF and UF of an oil-in-water emulsion under various transmembrane pressures (TMP). A significant impact of the TMP on the internal fouling of a MF PES membrane was highlighted, whereas almost no impact of the TMP was noticed in the case of an UF PAN membrane. The developed methodology using the quantification of the electrokinetic leakage phenomenon allows distinguishing the contributions of internal and external (surface) fouling. These findings offer new application of tangential electrokinetic measurements to gain more insight into the characterization of membrane fouling