Search results for " Models"
showing 10 items of 4240 documents
Caribbean Plate margin evolution: constraints and current problems
2021
Oceanic crust was generated at multiple spreading centres during the Jurassic and Early Cretaceous, forming a "proto-Caribbean" oceanic domain. During the Cretaceous, part of that crustal domain thickened into an oceanic plateau, of petrologic Mid-Ocean Ridge (MOR) to Ocean Island Basalt (OIB) affinity. Simultaneously, the South and North American continental plates developed rifting and tholeiitic magmatism in the Middle America region (Venezuela and Cuba). The rifting created space for the proto-Caribbean oceanic domain. Petrological and regional correlations suggest that, beginning in the Cretaceous, the proto-Caribbean domain was involved into two main stages of subduction, referred to …
Carotid atherosclerosis and chronic hepatitis C: A prospective study of risk associations
2011
BACKGROUND AND AIMS: There are contrasting results in studies of cardiovascular risk in patients with genotype 1 chronic hepatitis C (G1 CHC). We evaluated the prevalence of carotid atherosclerosis compared with a control population in order to assess the potential association between atherosclerosis, host and viral factors, and liver histological features. MATERIALS AND METHODS: One hundred seventy-four consecutive biopsy-proven G1 CHC patients were evaluated by anthropometric and metabolic measurements. One hundred seventy-four patients attending an outpatient cardiology unit were used as controls. Intima-media thickness (IMT) and carotid plaques, defined as focal thickening of > 1.3 mm a…
Relationship between carotid intima-media thickness and non valvular atrial fibrillation type.
2015
OBJECTIVE: Carotid intima-media thickness (cIMT) is a surrogate marker of subclinical atherosclerosis and it is able to predict both coronary and cerebral vascular events. No data exist on the association between cIMT and non valvular atrial fibrillation (NVAF) type. We conduct this study with the aim to analyze the association between abnormal cIMT and NVAF type. METHODS: A cross-sectional study of the "Atrial fibrillation Registry for Ankle-brachial index Prevalence Assessment-Collaborative Italian Study (ARAPACIS)" has been performed. Among 2027 patients enrolled in the ARAPACIS, 673 patients, who underwent carotid ultrasound examination to assess cIMT, were included in the study. RESULT…
Association between asymptomatic carotid atherosclerosis and degenerative aortic stenosis.
2012
OBJECTIVE: Degenerative aortic stenosis shows similarities with atherosclerosis. To confirm the hypothesis that aortic stenosis is an "atherosclerosis-like" disease, we investigated the association between degenerative aortic stenosis and atherosclerosis of carotid arteries. METHODS: We studied 270 consecutive patients, 135 with degenerative aortic stenosis (trans-aortic peak velocity ≥ 2 m/sec) and other 135 subjects without aortic valve disease. All patients underwent echocardiography and ultrasound scan of the supra-aortic trunks to assess the presence of plaque and/or intima-media thickening (IMT). RESULTS: Atherosclerosis of carotid arteries (IMT and plaque) was significantly more freq…
Changes in ultrasound-assessed carotid intima-media thickness and plaque with a Mediterranean diet: a substudy of the PREDIMED trial.
2014
OBJECTIVE - : The Prevención con Dieta Mediterránea (PREDIMED) trial showed that a Mediterranean diet (MedDiet) supplemented with either extra virgin olive oil or 30 g/d of mixed nuts reduced incident cardiovascular events compared with a control (low fat) diet. The mechanisms of cardiovascular protection afforded by MedDiets remain to be uncovered. We assessed the effect of both supplemented MedDiets on internal carotid intima-media thickness (ICA-IMT) and plaque height, the ultrasound features that best predict future cardiovascular events, in subjects at high cardiovascular risk. APPROACH AND RESULTS - : In a PREDIMED subcohort (n=175), plaque height and carotid IMT of 3 prespecified seg…
Metabolic syndrome (MetS) predicts cardio and cerebrovascular events in a twenty years follow-up. A prospective study.
2012
BACKGROUND AND PURPOSE: Metabolic syndrome (MetS) is a cluster of cardiovascular risk factors, considered as emerging and promoting atherosclerosis. This study aimed at the evaluation of the influence of MetS on the prediction of cerebro and cardiovascular events during a 20 years follow-up period in an asymptomatic population of middle-aged subjects. METHODS: We evaluated 529 asymptomatic persons through a prospective study. Study population was divided into two subgroups: patients with and without MetS. Echo-color-Doppler was used in order to assess the presence of subclinical atherosclerosis. A 20 years follow-up study was carried out in order to estimate the incidence of cerebro and car…
External stenting with a new polyester mesh reduces neointimal hyperplasia of vein grafts in a sheep model.
2007
Objective External stents placed around vein grafts have demonstrated effectiveness in reducing neointimal hyperplasia by preventing distension of the thin-walled vein grafts when exposed to arterial pressure. However, the ideal stent material has yet to be defined. The following study investigates the short- and long-term effects of an innovative polyester mesh stent designed with optimized adaptation of circumferential compliance. Methods Following in vitro definition of the ideal macro-porous polyester stent material, a total of 12 sheep underwent implantation of bilateral carotid artery vein graft bypasses. In six sheep, the short-term outcome (four weeks of implantation) was investigat…
Biostable Scaffolds of Polyacrylate Polymers Implanted in the Articular Cartilage Induce Hyaline-Like Cartilage Regeneration in Rabbits
2017
[EN] Purpose: To study the influence of scaffold properties on the organization of ¿in vivo¿ cartilage regeneration. Our hypothesis is that stress transmission to the cells seeded inside the scaffold pores or surrounding it, which is highly dependent on the scaffold properties, determine differentiation of both mesenchymal cells and dedifferentiated autologous chondrocytes. Methods: Four series of porous scaffolds made of different polyacrylate polymers, previously seeded with cultured rabbit chondrocytes or without cells preseeded, were implanted in cartilage defects in rabbits. Subchondral bone was always injured during the surgery in order to allow blood to reach the implantation site an…
Genetic abrogation of the fibronectin-α5β1 integrin interaction in articular cartilage aggravates osteoarthritis in mice.
2018
The balance between synthesis and degradation of the cartilage extracellular matrix is severely altered in osteoarthritis, where degradation predominates. One reason for this imbalance is believed to be due to the ligation of the α5β1 integrin, the classic fibronectin (FN) receptor, with soluble FN fragments instead of insoluble FN fibrils, which induces matrix metalloproteinase (MMP) expression. Our objective was to determine whether the lack of α5β1-FN binding influences cartilage morphogenesis in vivo and whether non-ligated α5β1 protects or aggravates the course of osteoarthritis in mice. We engineered mice (Col2a-Cre;Fn1RGE/fl), whose chondrocytes express an α5β1 binding-deficient FN, …
Dose Responsive Effects of Subcutaneous Pentosan Polysulfate Injection in Mucopolysaccharidosis Type VI Rats and Comparison to Oral Treatment
2014
Background We previously demonstrated the benefits of daily, oral pentosan polysulfate (PPS) treatment in a rat model of mucopolysaccharidosis (MPS) type VI. Herein we compare these effects to once weekly, subcutaneous (s.c.) injection. The bioavailability of injected PPS is greater than oral, suggesting better delivery to difficult tissues such as bone and cartilage. Injected PPS also effectively treats osteoarthritis in animals, and has shown success in osteoarthritis patients. Methodology/principal findings One-month-old MPS VI rats were given once weekly s.c. injections of PPS (1, 2 and 4 mg/kg, human equivalent dose (HED)), or daily oral PPS (4 mg/kg HED) for 6 months. Serum inflammato…