Search Results
Results 201 - 250 of 1714
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Craiem Damian - - 2010
The ambulatory arterial stiffness index (AASI) is claimed to be a new estimator for arterial rigidity. It was recently defined as one minus the slope of the linear regression of systolic to diastolic ambulatory pressure during 24 h. Although several reports testify its clinical relevance, the explanation of how this ...
Duivenvoorden Raphaël - - 2010
Low endothelial shear stress (ESS) elicits endothelial dysfunction. However, the relationship between ESS and arterial remodeling and arterial stiffness is unknown in humans. We developed a 3.0-T MRI protocol to evaluate the contribution of ESS to arterial remodeling and stiffness. Fifteen young (aged 26 ± 3 years) and 15 older ...
van den Broek Chantal N - - 2011
Constitutive models describing the arterial mechanical behavior are important in the development of catheterization products, to be used in arteries with a specific radius. To prove the possible existence of a constitutive model that, provided with a generic set of material and geometric parameters, is able to predict the radius-specific ...
Segade Fernando - - 2010
Arterial Tortuosity Syndrome (ATS) is a heritable disease characterized by twisting and lengthening of the major arteries, hypermobility of the joints, and laxity of skin. ATS is caused by mutations in SLC2A10, encoding Glucose Transporter 10 (GLUT10). The current model of ATS holds that loss of GLUT10 at the nuclear ...
Zócalo Yanina - - 2010
This study aimed to characterize the following: (i) in chronically hemodialyzed subjects (CHDSs), with and without diabetic nephropathy (DN), and in healthy subjects (non-CHDSs) different arterial pathways stiffness to determine potential pathology-dependent, etiology- and/or pathway-dependent differences; and (ii) the biomechanical mismatch (BM) between arteries from non-CHDSs or CHDSs (with and ...
Sokolis Dimitrios P - - 2010
A plethora of phenomenological and structure-motivated constitutive models have thus far been used as pseudoelastic descriptors in arterial biomechanics, but their parameters have not been explicitly correlated with histology. This study associated biaxial histological data with strain-energy function (SEF) parameters derived from uniaxial tension data of arteries from different topographical ...
Billaut Francois - - 2010
The ability to repeatedly generate maximum power output is usually accompanied by neuromuscular adjustments. PURPOSE: This study aimed to explore the occurrence of arterial O2 desaturation during prolonged repeated-sprint ability (RSA) testing and its relationship to neuromuscular activity, as evidenced by changes in surface integrated electromyogram (iEMG). METHODS: Fifteen, national-level ...
Nixon Alexander M - - 2010
Atherosclerosis and intracranial saccular aneurysms predictably localize in areas with complex arterial geometries such as bifurcations and curvatures. These sites are characterized by unique hemodynamic conditions that possibly influence the risk for these disorders. One hemodynamic parameter in particular has emerged as a key regulator of vascular biology--wall shear stress ...
Thapar A - - 2010
The national abdominal aortic aneurysm (AAA) screening programme measures internal wall diameter; however, current UK intervention criteria use external wall diameter. Our aim was to determine the clinical significance of the difference between these two measurements. Fifty patients on an aneurysm surveillance programme were ultrasound scanned by two experienced vascular ...
Laing Susan T - - 2010
Vascular smooth muscle cells (VSMCs) are important targets in the treatment of atherosclerosis. However, the arterial media, where the majority of VSMCs reside, have proven to be a difficult target for drug/gene delivery. We have demonstrated that ultrasound enhances drug/gene delivery to VSMCs in vitro by using echogenic immunoliposomes (ELIPs) ...
Eryilmaz Salih - - 2010
Reduced arterial elasticity is an important mediator of accelerated atherogenesis and consequent increased cardiovascular morbidity in obstructive sleep apnea (OSA). The aim of our study was to investigate whether continuous positive airway pressure (CPAP) therapy may improve arterial elasticity in subjects with OSA. In 44 subjects with OSA, we measured ...
Krasiński Z - - 2010
OBJECTIVE: To evaluate the relationship between the biomechanical properties and the structure of elastic components in different veins used for vascular reconstruction. DESIGN: In vitro experimental study. MATERIAL AND METHODS: Groups of 30 samples of incompetent saphenous veins (rSV), competent saphenous veins (cSV) and femoral veins (FVs) were compared following ...
Watton P N - - 2011
A fluid-solid-growth (FSG) model of saccular cerebral aneurysm evolution is developed. It utilises a realistic two-layered structural model of the internal carotid artery and explicitly accounts for the degradation of the elastinous constituents and growth and remodelling (G&R) of the collagen fabric. Aneurysm inception is prescribed: a localised degradation of ...
Rachev Alexander - - 2011
A structure-based mathematical model for the remodeling of arteries in response to sustained hypertension is proposed. The model is based on the concepts of volumetric growth and constitutive modeling of the arterial tissue within the framework of the constrained mixture theory. The major novel result of this study is that ...
Schyma Christian - - 2011
A 57-year-old employee in a military scientific institute was found acephalous in a supine position in an anteroom to the bunker. On the walls was abundant spattering of blood and tissue, concentrated above shoulder height. A mobile ignition device stood on the control desk. The complete destruction of the head ...
Wiernicki Ireneusz - - 2010
The maintenance of an arterial elastin's integrity is essential in the prevention of abdominal aortic aneurysm (AAA) development. So far, the effect of intraluminal thrombus (ILT) thickness on the elastolytic activity within the AAA wall has not been studied. In the present study the hypothesis that thin thrombus is associated ...
Borović Milica Labudović - - 2010
Coronary artery by-pass grafting (CABG) with arterial grafts is widely accepted as the procedure of choice in the treatment of coronary ischemic disease. It brings back focus on morphological studies of arteries used as conduits in this procedure. One of the most frequently used CABG grafts is the internal thoracic ...
Cinthio Magnus - - 2010
Using a recently developed high-resolution noninvasive ultrasonic method, we recently demonstrated that the intima-media complex of the common carotid artery show a bidirectional multiphasic longitudinal displacement of the same magnitude as the diameter change during the cardiac cycle. The longitudinal movement of the adventitial region was smaller, thus, we identified ...
Chung Ada W Y - - 2010
Abnormalities of vascular function and accumulation of oxidative stress have been associated with chronic kidney disease (CKD). Dialysis modalities, peritoneal dialysis (PD) and haemodialysis (HD) may differentially impact on vascular function and oxidative stress. Patients undergoing living donor transplantation were studied for vascular stiffness using pulse wave velocity measurements, and ...
Maltete David - - 2010
Because an underlying arteriopathy might contribute to the development of intracranial aneurysms (IAs), we assessed the elastic properties of proximal conduit arteries in patients with IA. In 27 patients with previous ruptured IA and 27 control subjects matched for age, gender and BMI, we determined arterial pressure, internal diameter, intima-media ...
Hamburg Naomi M NM Evans Department of Medicine and Whitaker Cardiovascular Institute, Boston University School of Medicine, Boston, MA, USA. - - 2010
Maladaptive peripheral arterial remodeling, which leads to large arteries with low shear stress, may be associated with increased cardiovascular risk. We tested the hypothesis that arterial enlargement in severe obesity represents maladaptive remodeling and that weight reduction would reverse this process. We evaluated brachial arterial diameter and flow using ultrasound ...
Torii Ryo - - 2010
The aim of this study was to develop a fully subject-specific model of the right coronary artery (RCA), including dynamic vessel motion, for computational analysis to assess the effects of cardiac-induced motion on hemodynamics and resulting wall shear stress (WSS). Vascular geometries were acquired in the right coronary artery (RCA) ...
Agger Peter - - 2010
BACKGROUND: TachoComb has frequently been used for the treatment of both venous and arterial bleeding. However, anaphylactic reactions have been reported after repeated use of hemostatic agents containing aprotinin such as TachoComb. Because aprotinin is also associated with risk of renal failure, manufacturing of a new product--TachoSil--which lacks aprotinin seems ...
Keenan Niall G NG Cardiovascular Magnetic Resonance Unit, Royal Brompton Hospital, London, - - 2010
To validate cardiovascular magnetic resonance (CMR) arterial wall volume measurement using whole arterial specimens ex vivo. Twenty cadaveric carotid arteries (from 10 patients) were fixed in formaldehyde and imaged with a clinical T1-weighted 2D CMR sequence and, for imaging validation, with a high-resolution 3D sequence. Histological validation was performed by ...
Vacek Thomas P - - 2010
Remodeling by its very nature implied synthesis and degradation of extracellular matrix (ECM) proteins. Although oxidative stress, matrix metalloproteinase (MMP) and tissue inhibitor of metalloproteinase (TIMP) have been implicated in vascular remodeling, the differential role of MMPs versus TIMPs and oxidative stress in vascular remodeling was unclear. TIMP-3 induced vascular ...
Fischer Edmundo Cabrera - - 2010
The aims were to characterize in muscular arteries (a) the passive and active effects of the adventitia on vessel biomechanical properties and conduit function (CF), and (b) potential differences between the adventitial role in elastic and muscular arteries. Ovine femoral arteries were studied in vivo and in vitro (reduced smooth ...
Duprey A - - 2010
OBJECTIVE: Ascending thoracic aortic aneurysms (ATAA) are a life-threatening condition due to the risk of rupture or dissection. This risk is increased in the presence of a bicuspid aortic valve (BAV). The purpose of this study was to provide data on the elastic modulus of aortic wall of ATAA using ...
Yamamoto Masuki - - 2010
Chronic obstructive pulmonary disease is mainly characterized by irreversible airflow limitation, and its major pathological change is alveolar destruction and enlargement, which induces emphysema. In this study, we used stereoscopic microscopy to observe the cut surfaces of 21 surgically resected or autopsied lungs showing centriacinar emphysema. We identified columnar structures ...
Bosman Willem-Maarten P F - - 2010
Aortic Customize is a new concept for endovascular aortic aneurysm repair in which a non polymerized elastomer is injected to fill the aneurysm sac around a balloon catheter. The aim of this in vitro study was to investigate the extent of aneurysm wall stress reduction by the presence of a ...
Smodlaka H - - 2010
Phocid seals exhibit vascular adaptations that allow them to undertake prolonged deep dives. These vascular adaptations are either unique to phocids, or are modified vascular equivalents to those present in terrestrial mammals. One such adaptation, the aortic bulb, is a spherical enlargement of the ascending aorta specific to phocid seals. ...
Hitchcock Kathryn E - - 2010
The goal of this study was to determine whether targeted, Rhodamine-labeled echogenic liposomes (Rh-ELIP) containing nanobubbles could be delivered to the arterial wall, and whether 1-MHz continuous wave ultrasound would enhance this delivery profile. Aortae excised from apolipoprotein-E-deficient (n=8) and wild-type (n=8) mice were mounted in a pulsatile flow system ...
Pazos V - - 2010
The comparison, evaluation, and optimization of new techniques, models, or algorithms often require the use of realistic deformable test phantoms. The purpose of this paper is to present a multilayer deformable test specimen mimicking an atherosclerotic coronary artery, suitable for mechanical testing and intravascular imaging. Mock arteries were constructed in ...
Gaubatz John W JW Department of Medicine, Baylor College of Medicine, 6565 Fannin St, Houston, TX 77030, - - 2010
To examine the relationship of plasma levels of matrix metalloproteinases (MMPs) and tissue inhibitor of metalloproteinase 1 (TIMP-1) with carotid artery characteristics measured by MRI in a cross-sectional investigation among Atherosclerosis Risk in Communities Carotid MRI Study participants. A stratified random sample was recruited based on intima-media thickness from a ...
Grond-Ginsbach Caspar - - 2010
Arterial dissection (AD) is defined as the longitudinal splitting up of the arterial wall caused by intramural bleeding. It can occur as a spontaneous event in all large and medium sized arteries. The histological hallmark of AD is medial degeneration. Histological investigations, gene expression profiling and proteome studies of affected ...
Maier A - - 2010
As a degenerative and inflammatory desease of elderly patients, about 80% of abdominal aortic aneurysms (AAA) show considerable wall calcification. Effect of calcifications on computational wall stress analyses of AAAs has been rarely treated in literature so far. Calcifications are heterogeneously distributed, non-fibrous, stiff plaques which are most commonly found ...
Novoa Ana M - - 2010
OBJECTIVE: To assess the effectiveness of speed cameras in reducing the numbers of crashes and people injured on the arterial roads of Barcelona, and to assess their long-term effectiveness on the beltway. METHODS: Time series analyses were performed separately for the arterial roads and the beltway. The stretches of arterial ...
Shum Judy - - 2010
PURPOSE: Quantitative measurements of wall thickness in human abdominal aortic aneurysms (AAAs) may lead to more accurate methods for the evaluation of their biomechanical environment. METHODS: The authors describe an algorithm for estimating wall thickness in AAAs based on intensity histograms and neural networks involving segmentation of contrast enhanced abdominal ...
Gasser T Christian - - 2010
The reliable assessment of Abdominal Aortic Aneurysm rupture risk is critically important in reducing related mortality without unnecessarily increasing the rate of elective repair. Intra-luminal thrombus (ILT) has multiple biomechanical and biochemical impacts on the underlying aneurysm wall and thrombus failure might be linked to aneurysm rupture. Histological slices from ...
Biasetti Jacopo - - 2010
Abdominal Aortic Aneurysms (AAAs), i.e., focal enlargements of the aorta in the abdomen are frequently observed in the elderly population and their rupture is highly mortal. An intra-luminal thrombus is found in nearly all aneurysms of clinically relevant size and multiply affects the underlying wall. However, from a biomechanical perspective ...
Coats Paul - - 2010
Peripheral vascular disease (PVD) is associated with numerous pathophysiological adaptations of the microvasculature. Considering this, active and passive pressure-dependent and pressure-independent mechanisms of vascular control were studied in small resistance arteries isolated from patients with PVD. Using pressure myography and confocal microscopy, human skeletal muscle arteriolar structure and function were ...
Venkatasubramanian Ramji T - - 2010
Applications involving freeze-thaw, such as cryoplasty or cryopreservation can significantly alter artery biomechanics including an increase in physiological elastic modulus. Since artery biomechanics plays a significant role in hemodynamics, it is important to understand the mechanisms underlying these changes to be able to help control the biomechanical outcome post-treatments. Understanding ...
Hunter Kendall S - - 2010
Developing clinical work suggests that vascular stiffening plays a role in the progression of pulmonary hypertension (PH), while recent studies in animal models of hypoxic PH have found significant proximal vascular stiffening in the diseased population. Here, we develop and validate a minimally invasive, clinically realizable method to estimate the ...
Wang Ruoya - - 2010
Identification of an appropriate stress-free reference configuration is critically important in providing a reasonable prediction of the intramural stress distribution when performing biomechanical analyses on arteries. The stress-free state is commonly approximated as a radially cut ring that typically opens into a nearly circular sector, relieving much of the circumferential ...
Koskinen Juha - - 2010
BACKGROUND: The reversibility of ultrasonographic vascular changes associated with the metabolic syndrome (MetS) recovery is unknown. We examined whether spontaneous recovery from MetS (according to the International Diabetes Federation definition) has a favorable effect on vascular properties and evaluated the associations between lifestyle factors and MetS recovery. METHODS AND RESULTS: ...
McClure Michael J - - 2010
Throughout native artery, collagen, and elastin play an important role, providing a mechanical backbone, preventing vessel rupture, and promoting recovery under pulsatile deformations. The goal of this study was to mimic the structure of native artery by fabricating a multi-layered electrospun conduit composed of poly(caprolactone) (PCL) with the addition of ...
L? Wei-Dong - - 2010
In this study, valved photooxidatively crosslinked acellular bovine jugular vein conduits (BJVCs) were implanted in young dogs to reconstruct the connections of pulmonary arteries and right ventricles, with acellular conduits used as controls. All acellular conduits had moderate to severe valvular dysfunction and were explanted at 1-month implantation (n = ...
Murphy Jonathan B - - 2010
The benefit of coronary stent implantation is reduced by excessive intimal hyperplasia which re-narrows the artery and the prevention of which is still a primary concern for clinicians. Abnormal hemodynamics create non-physiological viscous stress on the artery wall, one of the root causes of intimal hyperplasia following stent implantation. A ...
Rodríguez Javier O - - 2010
Fractal geometry is employ to characterize the irregular objects and had been used in experimental and clinic applications. Starting from a previous work, here we made a theoretical research based on a geometric generalization of the experimental results, to develop a theoretical generalization of the stenotic and restenotic process, based ...
O'Rourke M J - - 2010
The flow fields within three patient-specific models of an abdominal aortic aneurysm (AAA) were investigated under steady laminar inflow conditions over a range of Reynolds numbers. Each model extended from the renal arteries to downstream of the iliac bifurcation. The aneurysms (referred to as models A, B, and C) are ...
Rosenbaum Pearl S - - 2010
A 14-year-old girl presented with sudden, painless loss of vision in the left eye. Complete ophthalmologic examination including fluorescein angiography revealed an impending central vein occlusion and a branch retinal artery occlusion inferotemporally. One month later, there was a non-ischemic central retinal vein occlusion of the same eye. Systemic evaluation ...
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