Myelin Proteomics: Molecular Anatomy of an Insulating Sheath

Fast-transmitting vertebrate axons are electrically insulated with multiple layers of nonconductive plasma membrane of glial cell origin, termed myelin. The myelin membrane is dominated by lipids, and its protein composition has historically been viewed to be of very low complexity. In this review, we discuss an updated reference compendium of 342 proteins associated with central nervous system myelin that represents a valuable resource for analyzing myelin biogenesis and white matter homeostasis. Cataloging the myelin proteome has been made possible by technical advances in the separation and mass spectrometric detection of proteins, also referred to as proteomics. This led to the identification of a large number of novel myelin-associated proteins, many of which represent low abundant components involved in catalytic activities, the cytoskeleton, vesicular trafficking, or cell adhesion. By mass spectrometry-based quantification, proteolipid protein and myelin basic protein constitute 17% and 8% of total myelin protein, respectively, suggesting that their abundance was previously overestimated. As the biochemical profile of myelin-associated proteins is highly reproducible, differential proteome analyses can be applied to material isolated from patients or animal models of myelin-related diseases such as multiple sclerosis and leukodystrophies

Accurate Left Ventricular Segmentation Based on Morphological Watershed Transformation Towards 3D Visualization

International audienceThe current challenge for image treatment, targeting the heart ventricles (LV and RV), consists on ensuring an accurate automatic segmentation aiming to identify the myocardial contours. In this paper we propose an automatic watershed-based segmentation of the left ventricle (LV)based on topology, geometry and brightness priors. We attempted to demonstrate the accuracy of our proposed approach by comparing it with other manual segmentations carried out by two clinical experts, on 20 patients. In the aim of obtaining an accurate 3D reconstruction, we propose the volumetric object reconstruction method using The Visualization Toolkit VTK .Furthermore, the 3D+t assessment is used for the examination of the dynamic behavior of the LV to reveal regions of myocardial dysfunction