Search results for "Matrix"
showing 10 items of 3205 documents
Short-term atorvastatin treatment does not modify neointimal morphology but reduces MMP-2 expression in normocholesterolemic rabbit stented arteries.
2006
The aim of our study was to explore some potential pleiotropic effects of atorvastatin, after stenting in the iliac arteries of normocholesterolemic rabbits. On day 0, 27 rabbits underwent stent implantation and were randomized into either the control group (standard chow, CTRL, n = 15) or the atorvastatin group (10 mg/kg/d per os, Ator, n = 12). On day 30, the stented arteries were harvested for histomorphometry and neointimal analysis [macrophages, matrix metalloproteinases (MMP-2), tissue inhibitor of metalloproteinase-2, vascular smooth muscle cells, and collagen]. Atorvastatin did not induce significant histomorphometric and inflammatory modifications but reduced neointimal expression …
Rapamycin vermindert die Neointimaausbildung nach vaskulärer Schädigung
2003
Background: Proliferation and migration of vascular smooth muscle cells (SMCs) mark the key processes in the development of bypass graft disease and during neointima formation in restenosis after angioplasty. Growth factors are potent SMC mitogens as they are involved in SMC proliferation and in extracellular matrix (ECM) synthesis. Based on these premises, we examined the effect of the proliferation inhibitor rapamycin in human SMC culture and in a rabbit vascular injury model. Materials and methods: Injection of rapamycin or its vehicle was performed with an infusion-balloon catheter directly into the vessel wall during vascular injury. The intima/media ratio was determined histologicall…
Roles of molecules involved in epithelial/mesenchymal transition during angiogenesis
2007
Formation of vessels requires "epithelial-mesenchymal" transition of endothelial cells, with several modifications at the level of endothelial cell plasma membranes. These processes are associated with redistribution of cell-cell and cell-substrate adhesion molecules, cross talk between external ECM and internal cytoskeleton through focal adhesion molecules and the expression of several proteolytic enzymes, including matrix metalloproteases and serine proteases. These enzymes with their degradative action on ECM components, generate molecules acting as activators and/or inhibitors of angiogenesis. The purpose of this review is to provide an overview of the molecules involved in epithelial-m…
Cajal–Retzius cells: Update on structural and functional properties of these mystic neurons that bridged the 20th century
2014
Cajal-Retzius cells (CRc) represent a mostly transient neuronal cell type localized in the uppermost layer of the developing neocortex. The observation that CRc are a major source of the extracellular matrix protein reelin, which is essential for the laminar development of the cerebral cortex, attracted the interest in this unique cell type. In this review we will (i) describe the morphological and molecular properties of neocortical CRc, with a special emphasize on the question which markers can be used to identify CRc, (ii) summarize reports that identified the different developmental origins of CRc, (iii) discuss the fate of CRc, including recent evidence for apoptotic cell death and a p…
Electronmicroscopical Contrast by Palladium Chloride
1986
Thin sections of glutaraldehyde-fixed, epoxy resin-embedded bone marrow from rats were treated with 2% palladium chloride in 2% concentrated HCl. This procedure was found to induce high electron density in chromatin from all cell types and in cytoplasmic granules of neutrophils and eosinophils. In the latter, the crystalline body showed more contrast than the matrix.
Analysis of Nicotine and Its Oxidation Products in Nicotine Chewing Gum by a Molecularly Imprinted Solid-Phase Extraction
2000
Chromatographic stationary phases showing exceptional selectivity for nicotine can be prepared by the technique of molecular imprinting. Such phases were used in the search for a rapid cleanup step for nicotine and some of its oxidation products in chewing gum formulations. Thus, using an organic mobile phase, the nicotine analytes from chewing gums dissolved in nonpolar solvent were retained, whereas the nonpolar matrix eluted close to the void peak. A subsequent switch to an acidic mobile phase resulted in elution of the analytes as one sharp peak. Due to weak binding of the less basic oxidation products, other imprinted polymers were tested, and the solid-phase extraction procedure was o…
HSP90 and eNOS partially co-localize and change cellular localization in relation to different ECM components in 2D and 3D cultures of adult rat card…
2007
Background information. Cultivation techniques promoting three-dimensional organization of mammalian cells are of increasing interest, since they confer key functionalities of the native ECM (extracellular matrix) with a power for regenerative medicine applications. Since ECM compliance influences a number of cell functions, Matrigel-based gels have become attractive tools, because of the ease with which their mechanical properties can be controlled. In the present study, we took advantage of the chemical and mechanical tunability of commonly used cell culture substrates, and co-cultures to evaluate, on both two- and three-dimensional cultivated adult rat cardiomyocytes, the impact of ECM c…
Development of a polydimethylsiloxane–thymol/nitroprusside composite based sensor involving thymol derivatization for ammonium monitoring in water sa…
2014
This report describes a polydimethylsiloxane (PDMS)-thymol/nitroprusside delivery composite sensor for direct monitoring of ammonium in environmental water samples. The sensor is based on a PDMS support that contains the Berthelot's reaction reagents. To prepare the PDMS-thymol/nitroprusside composite discs, thymol and nitroprusside have been encapsulated in the PDMS matrix, forming a reagent release support which significantly simplifies the analytical measurements, since it avoids the need to prepare derivatizing reagents and sample handling is reduced to the sampling step. When, the PDMS-thymol/nitroprusside composite was introduced in water samples spontaneous release of the chromophore…
Heparin–polynitroxides: Synthesis and preliminary evaluation as cardiovascular EPR/MR imaging probes and extracellular space-targeted antioxidants
2011
We report here the synthesis of heparin-polynitroxide derivatives (HPNs) in which nitroxide moieties are linked either to uronic acid or glycosamine residues of the heparin macromolecule. HPNs have low anticoagulant activity, possess superoxide scavenging properties, bind to the vascular endothelium/extra-cellular matrix and can be detected by EPR and MRI techniques. As the vascular wall-targeted redox-active paramagnetic compounds, HPNs may have both diagnostic (molecular MRI) and therapeutic (ecSOD mimics) applications.
Mixed and Nitsche's discretizations of frictional contact-mechanics in fractured porous media
2023
This work deals with the discretization of single-phase Darcy flows in fractured and deformable porous media, including frictional contact at the matrix-fracture interfaces. Fractures are described as a network of planar surfaces leading to so-called mixed dimensional models. Small displacements and a linear poro-elastic behavior are considered in the matrix. One key difficulty to simulate such coupled poro-mechanical models is related to the formulation and discretization of the contact mechanical sub-problem. Our starting point is based on the mixed formulation using facewise constant Lagrange multipliers along the fractures representing normal and tangential stresses. This is a natural c…