Search Results
Results 251 - 300 of 1743
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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 KE Department of Biomedical Engineering, University of Cincinnati, Cincinnati, OH, United States. - - 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 ...
Lou Min - - 2010
Dolichoectasia (dilatative arteriopathy) describes marked elongation, widening, and tortuosity of arteries. The intracranial vertebral and basilar arteries are preferentially involved. Dolichoectatic arteries usually have an abnormally large external diameter and a thin arterial wall, with degeneration of the internal elastic lamina, multiple gaps in the internal elastica, thinning of the ...
Warnock James N - - 2010
BACKGROUND AND AIM OF THE STUDY: Although the vasoactive agents, angiotensin II (Ang II) and 5-hydroxytryptamine (5-HT) are implicated in aortic heart valve disease, it is unclear how these compounds alter the biomechanical properties of valve leaflet tissue. The study aim was to characterize temporal changes in the elastic modulus ...
Hussain M - - 2010
The Carotid Artery Insufficiency Retinopathy (CAIR) is an uncommon sign of carotid artery obstruction. It is mainly found in patients with complete occlusion or severe obstruction of internal Carotid Artery (ICA). Retinopathy is caused by progressive and chronic hypoxia to ocular tissues. The purpose of the study is to describe ...
Hinson Holly E - - 2010
The use of antithrombotic therapy (anticoagulants and/or antiplatelets) in the setting of traumatic cervical arterial dissection (CAD) for the prevention of stroke remains controversial. This issue is further complicated by the frequent co-existence of intracranial hemorrhage (ICH) and other intracranial injuries, and also the wide variability in treatment due to ...
Javey Golnaz - - 2010
The authors report the management of a ruptured retinal arterial macroaneurysm and associated hemorrhages with intravitreal injections of bevacizumab. A 79-year-old woman presented with a history of systemic arterial hypertension and a ruptured retinal arterial macroaneurysm with pre-retinal, intraretinal, and subretinal hemorrhages extending into the macula. Visual acuity at presentation ...
Biswas Rohan - - 2010
Ultrasonography for the noninvasive assessment of tissue properties has enjoyed widespread success. With the growing emphasis in recent years on arteriovenous fistulae (AVFs) for dialysis vascular access in patients with end-stage renal disease, and on reducing AVF failures, there is increasing interest in ultrasound for the preoperative evaluation of the ...
Teeter M G MG Department of Clinical Studies, University of Guelph, Ontario, - - 2010
Arterial calcification is found frequently in the pulmonary artery of racehorses, but the aetiology is unknown. Calcification might be associated with increased wall stress due to arterial geometry (shape) and exercise-induced hypertension. High wall stress levels are found in the regions associated with calcified lesion formation, exacerbated as transluminal pressure ...
Brum J J Instituto de Fisica, Facultad de Ciencias, Universidad de la Republica, Igua 4225, Montevideo, Uruguay. - - 2010
The early detection of biomechanical modifications in the arterial wall could be used as a predictor factor for various diseases, for example hypertension or atherosclerosis. In this work a transient elastography technique is used for the in vitro evaluation of the arterial wall elasticity. The obtained Young modulus is compared ...
Zajarevich N N CITEFA, Ministry of Defense, Villa Martelli, Buenos Aires, - - 2010
In this present paper, we showed that wavelet analysis (WA) has the potential for extracting specific features from measured arterial diameter and pressure waveforms. The fifth detail of the Daubechies 4 (Db4) wavelet appears to be the most appropriate level for application, in order to analyze artery waveforms and was ...
Li Ye Y Brunel Institute for Bioengineering, Brunel University, Greater London, UK. - - 2010
Wave speed is one of the key factors describing wave propagation in arteries [1]. Local wave speed is directly related to the arterial wall properties [2]. With aging, arterial wave speed increases due to the stiffening of arterial wall, and also related to arterial disease.
Bernal Miguel M Mayo Clinic College of Medicine, Rochester, MN 55905, USA. - - 2010
Arterial elasticity has gained importance in the past few decades as a predictor of cardiovascular diseases and mortality. Measuring the speed of propagation of the pressure wave traveling in the wall of the arteries has been used for a very long time to estimate the mechanical properties of the artery. ...
Pessana F F Electronic Department, Buenos Aires Regional Faculty, National Technological University, Medrano 951, (C1179AAQ), Ciudad Autónoma de Buenos Aires, Argentina. - - 2010
Wall artery viscoelastic properties (WAVP) are correlated with structural and functional state of the arterial system. An accurate estimation of these properties is achieved measuring wall instantaneous diameter and pressure signals. The aim of this work was to evaluate a new non invasive estimation method of the instantaneous arterial diameter ...
Balay G G Instituto de Fisica, Facultad de Ciencias, UdelaR, Montevideo, Uruguay. - - 2010
In several clinical and experimental circumstances, it is widely necessary to characterize the bio-mechanical changes induced by atherosclerosis to the arterial wall. In this context, the purpose of this paper is twofold. Firstly, to propose a low cost ultrasound setup to improve artery radii determination in elasticity experiments, based on ...
Xu Da D Department of Electrical and Computer Engineering, Michigan State University, East Lansing, MI 48824, USA. - - 2010
Pulse wave velocity (PWV) determined through the foot-to-foot time delay between carotid and femoral artery waveforms is an index of aortic stiffness with proven clinical value. However, handheld transducers, which are often used to non-invasively measure the waveforms, are prone to motion artifact that may limit the full potential of ...
Misra Sanjay S Department of Radiology, Mayo Clinic College of Medicine, 200 First Street SW, Alfred 6460, Rochester, MN 55905, USA. misra.sanjay@mayo.edu - - 2010
To evaluate the wall shear stress, protein expression of matrix metalloproteinase (MMP)-2 and MMP-9 and tissue inhibitor of matrix metalloproteinase (TIMP)-1 and TIMP-2, and vessel area over time in a porcine model for polytetrafluoroethylene (PTFE) hemodialysis grafts. In 21 pigs, subtotal renal infarction was created, and 28 days later, a ...
Karmy-Jones Riyad R Riyad Karmy-Jones, Desarom Teso, Nichole Jackson, Division of Cardiac, Thoracic and Vascular Surgery, Southwest Washington Medical Center, Suite 330 400 NE Mother Joseph Place, Vancouver, WA 98664, United - - 2009
Traumatic thoracic aortic injury remains a major cause of death following motor vehicle accidents. Endovascular approaches have begun to supersede open repair, offering the hope of reduced morbidity and mortality. The available endovascular technology is associated with specific anatomic considerations and complications. This paper will review the current status of ...
Lindeman Jan H N - - 2010
An aneurysm of the aorta is a common pathology characterized by segmental weakening of the artery. Although it is generally accepted that the vessel-wall weakening is caused by an impaired collagen metabolism, a clear association has been demonstrated only for rare syndromes such as the vascular type Ehlers-Danlos syndrome. Here ...
Huang Jianbin J Department of Molecular Biology, University of Texas Southwestern Medical Center, Dallas, TX, - - 2010
Loss of fibulin-4 during embryogenesis results in perinatal lethality because of aneurysm rupture, and defective elastic fiber assembly has been proposed as an underlying cause for the aneurysm phenotype. However, aneurysms are never seen in mice deficient for elastin, or for fibulin-5, which absence also leads to compromised elastic fibers. ...
Coutard Michèle - - 2010
BACKGROUND/AIM: The intraluminal thrombus (ILT) is considered to participate in abdominal aortic aneurysm (AAA) evolution. To assess whether this role proceeds via ILT influence on biological activity of the AAA wall, we studied the relationships between the levels of some relevant proteases and microparticles (MP) released by ILT versus wall ...
Georgakarakos E - - 2010
Using finite element analysis, we evaluated if the site of an aortic bleb, known to be prone to rupture, coincides with the location of peak wall stress (PWS) in a patient-specific abdominal aortic aneurysm (AAA) model. PWS was not located at the bleb site, even when stress values were estimated ...
Chung Sangwon - - 2010
Current surgical therapy for diseased vessels less than 6mm in diameter involves bypass grafting with autologous arteries or veins. Although this surgical practice is common, it has significant limitations and complications, such as occlusion, intimal hyperplasia and compliance mismatch. As a result, cardiovascular biomaterials research has been motivated to develop ...
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