Biomedical subjects

Andrea Remuzzi

Publications and source records attributed to Andrea Remuzzi.

21 records · Page 2Linked to original sources

PubMed2000

Effect of angiotensin-converting enzyme inhibition on glomerular basement membrane permeability and distribution of zonula occludens-1 in MWF rats.

The mechanism(s) by which angiotensin-converting enzyme (ACE) inhibitors prevent glomerular membrane loss of permselective function is still not understood. In male MWF rats, which develop spontaneous proteinuria with age, ACE inhibitors prevent proteinuria and increase glomerular ultrafiltration coefficient. These renoprotective effects are not associated with ultrastructural changes of capillary wall components. This study was undertaken to investigate whether ACE inhibitors modulate functional properties of glomerular basement membrane (GBM) and/or of epithelial cells, both of which have been suggested to play a role in the maintenance of the glomerular filtration barrier. The hydraulic and macromolecular permeability of the GBM were determined, by an in vitro filtration system, in untreated or lisinopril-treated rats and in Wistar rats taken as controls. By indirect immunofluorescence and immunoelectron microscopy, glomerular distribution of the tight junction protein zonula occludens- (ZO-1), a component of the slit diaphragm, was also studied. Results document that spontaneous proteinuria in MWF rats develops without significant changes in the permeability of the GBM to water and albumin, or in the ultrastructure of the podocyte foot processes, but is associated with an important alteration in the distribution of ZO-1 at the glomerular level. Lisinopril, which prevented proteinuria, also prevented glomerular redistribution of the protein. Thus, renoprotective effects of ACE inhibitors are not associated with changes in intrinsic functional properties of GBM, or ultrastructural changes of the epithelial cells, but rather with preservation of glomerular ZO-1 distribution and slit diaphragm function, which are essential for maintaining the filtration barrier.

Angiotensin-Converting Enzyme Inhibitors↗

PubMedDate not supplied

Geometric reconstruction for computational mesh generation of arterial bifurcations from CT angiography.

A methodology for patient-specific model reconstruction and computational mesh generation of arterial bifurcations from angio-CT scans is presented. Three-dimensional models were reconstructed with a level set technique, analyzed with a skeletoning algorithm and automatically decomposed into branches. Cooper scheme was then employed to generate high quality hexahedral mesh. We successfully applied our technique to the carotid bifurcations of two patients affected by severe atherosclerotic plaques. The proposed technique is fast, accurate and reproducible, and can be a useful tool for the evaluation of arterial fluid dynamics within conventional computed tomography investigations.

Aged↗

PubMedDate not supplied

Vascular smooth muscle cells on hyaluronic acid: culture and mechanical characterization of an engineered vascular construct.

Esterified hyaluronic acid (HYAFF) is routinely used for clinical tissue-engineering applications such as skin and cartilage. The material is degraded by neotissue formation and degradation products are highly biocompatible. In the present article we investigate the possibility to culture vascular smooth muscle cells on this biodegradable material for the generation of tubular constructs to be used for vascular tissue engineering. We have evaluated cell attachment and growth, and the possibility to obtain a three-dimensional tubular shape culture from flat HYAFF sheets. We also evaluated the mechanical properties of the cell constructs, using a specific testing protocol, and compared them with the properties of segments of porcine coronary artery. Morphology and viability tests demonstrated that vascular cells, either from porcine or human origin, adhere and grow on nonwoven meshes of HYAFF, and that precoating of the material with fibronectin or collagen had a modest effect on cell growth and extracellular matrix production. Cell growth reached a maximum 7 days after seeding. Simple wrapping of flat sheets of nonwoven meshes containing vascular cells around a cylindrical mandrel, and culture under static conditions for 14 days, yielded tubular constructs suitable for mechanical tests. Despite cell colonization, constructs showed lower mechanical resistance as compared with porcine coronary arteries. The material used and the technique developed result in highly cellularized tubular constructs. Whether the mechanical properties may be improved by dynamic culture conditions is worthy of investigation.

Animals↗