Search Results
Results 451 - 500 of 1743
< 5 6 7 8 9 10 11 12 13 14 15 >
Lammers Steven R - - 2008
Extracellular matrix remodeling has been proposed as one mechanism by which proximal pulmonary arteries stiffen during pulmonary arterial hypertension (PAH). Although some attention has been paid to the role of collagen and metallomatrix proteins in affecting vascular stiffness, much less work has been performed on changes in elastin structure-function relationships ...
Han Hai-Chao - - 2008
Tortuosity and kinking often occur in arteries and veins but the underlying mechanisms are poorly understood. It has been suggested recently that long arteries may buckle and become tortuosity due to reduced axial tension or hypertensive pressure, but very few studies have been done to establish the biomechanical basis for ...
Aoki Tomohiro - - 2008
BACKGROUND AND PURPOSE: A cerebral aneurysm (CA) causes catastrophic subarachnoid hemorrhage. Degradation of extracellular matrix in arterial walls is a prominent feature of cerebral aneurysms. We investigated the expression and role of cysteine cathepsins, collagen- and elastin- degrading proteinases, in CA progression. METHODS: CAs were induced in Sprague-Dawley rats with ...
Doostkam S - - 2008
In a study on amyloid deposits in vertebral arteries, many elderly patients showed amyloid deposits in the perivascular tissue. These proved to be senile systemic amyloidosis of the transthyretin-type by immunohistochemistry. Amyloid deposits were also found in the arterial wall. These intramural amyloid deposits showed significant affinity to elastic material ...
Wellnhofer E - - 2009
BACKGROUND: Local wall shear stress (WSS) has an impact on local remodelling of the vessel wall. WSS in turn strongly depends on local geometry. Our aim was to characterize patterns of local wall shear stress associated with distinct types of remodelling in coronary arteries. Vessel size and flow rates are ...
Jou L-D - - 2008
BACKGROUND AND PURPOSE: Hemodynamics is often recognized as one of the major factors in aneurysm rupture. Flow impingement, greater pressure, and abnormal wall shear stress are all indications for aneurysm rupture. Characterizing wall shear stress for intracranial aneurysms at similar anatomic locations may help in understanding its role. MATERIALS AND ...
Lin Alexander P - - 2008
The walls of conduit arteries undergo cyclic stretching from the periodic fluctuation of arterial pressure. Atherosclerotic lesions have been shown to localize to regions of excessive stretching of the arterial wall. We employed a displacement encoding with stimulated echoes (DENSE) sequence to image the motion of the common carotid artery ...
O'Rourke Michael F - - 2008
The subject of arterial stiffness as a modifiable risk factor is controversial and difficult to understand. The best approach here will be to assist readers to understand the issue and the basis of controversy. We also hope to show that the subject is not as overwhelming as it might appear. ...
Al-Dhibi Hassan - - 2008
To describe uncommon association between central retinal artery obstruction and dominant macular drusen in two young female patients. First patient, a 22-year-old female was presented with right central artery obstruction associated with bilateral dominant macular drusen. Systemic evaluation disclosed the presence of mitral valve regurge. Second patient, a 34-year-old female ...
Xiong Jiang - - 2008
An adenoviral vector carrying a recombinant tropoelastin (TE) gene with a Green Fluorescent Protein (GFP) tag adenoviral tropoelastin green fluorescent protein (AdTE-GFP) was transferred to aortic vascular smooth muscle cells (VSMCs) for studying the expression of recombinant elastin in vitro and the reconstruction of elastic fibers in vivo in experimental ...
Helderman F - - 2008
Aneurysms of the abdominal aorta enlarge until rupture occurs. We assume that this is the result of remodelling to restore wall stress. We developed a numerical model to predict aneurysm expansion based on this assumption. In addition, we obtained aneurysm geometry of 11 patients from computed tomography angiographic images to ...
Tateshima Satoshi - - 2008
BACKGROUND: The remodeling of arterial extra-cellular matrix induced by hemodynamic stimuli is involved in the process of atherosclerosis in the carotid and cerebral arteries. Scarce information is available on the relationship between atherosclerotic changes in brain aneurysms itself and its intra-aneurysmal hemodynamics. METHODS: Surgical exploration of a large MCA aneurysm ...
Cansever Tufan - - 2009
BACKGROUND: Risks related to rebleeding of a ruptured intracranial aneurysm have decreased. However, ischemic neurologic deficits related to vasospasm are still the leading causes of mortality and morbidity. It is well known that vasospasm is a dynamic process affected by various factors. The severity of vasospasm in animal models and ...
Yasmin - - 2008
Cardiovascular disease is the leading cause of death worldwide and premature arterial stiffening is a key contributor to this risk. A large body of evidence now points to arterial stiffness as an independent predictor of cardiovascular events. Stiffness can be assessed by a number of indices and is itself affected ...
Takemura Akihiro - - 2008
In this study, we analyzed the respiratory motion of the upper abdominal arteries preliminary to developing a method of respiratory motion correction for the roadmap technique used in vascular interventions. We retrospectively obtained six digital angiography sequences taken during respiration. The levels of the right and left hemidiaphragms and the ...
Kwon Gina P - - 2008
Extracellular deposition of low-density lipoprotein (LDL) in the arterial wall is an essential early step in atherosclerosis. This process preferentially occurs at arterial branch points, reflecting a regional variation in lipoprotein-arterial wall interactions. In this study, we characterized the submicron microstructure of arterial wall collagen and elastin to evaluate its ...
Sokolis Dimitrios P - - 2008
INTRODUCTION: Aortic function is an important determinant of pressure and flow in the entire cardiovascular system. This study aimed at evaluating segmental differences of aortic function and composition, in order to understand their clinical implications. METHODS: The thoracic aorta from each of 20 healthy pigs was divided into four and ...
Li Wen-Chun - - 2008
We explored the feasibility of human umbilical vein (HUV) as a small-caliber vessel substitute. HUVs of 50 fetuses were collected on spontaneous miscarriage or labor with the pregnant women's permission. Gestational age ranged 24-42 weeks, and parturients were 20-30 years old. Each sample was sliced into 5 mum frozen transverse ...
Ikeshita Kazuki - - 2008
The endothelial dysfunction is considered to be an initial step of atherosclerosis. Moreover, it was reported that the smooth muscle, which constructs the media of the artery, changes its characteristics due to early-stage atherosclerosis. Therefore, it is essential to develop a method for assessing the regional endothelial function and mechanical ...
Reneman Robert S - - 2008
Based upon theory, wall shear stress (WSS), an important determinant of endothelial function and gene expression, has been assumed to be constant along the arterial tree and the same in a particular artery across species. In vivo measurements of WSS, however, have shown that these assumptions are far from valid. ...
Epstein Kira - - 2008
The objective of this study was to determine the characteristics based on ultrasonographic examination of the stomach, duodenum, jejunum, cecum, and peritoneal fluid in normal adult ponies. Abdominal ultrasonographic examination was performed in nine unsedated standing ponies. The duodenum was examined at three sites and the jejunum in 12 regions. ...
Farhan Serdar - - 2009
BACKGROUND: The impaired compliance of large and medium-sized muscular arteries has been shown to correlate with the risk of adverse cardiovascular events. We assessed coronary artery distensibility using simultaneous intracoronary ultrasound and pressure wire measurements in porcine coronary arteries after implantation of paclitaxel-eluting (PES) and bare metal stents (BMS) and ...
Pagona Georgia - - 2008
Methods of insertion of azafullerenes in single-walled carbon nanotubes (SWNTs) at different temperatures were investigated, while the effects of the conditions applied on the structure of azafullerene-based peapods, namely, C59N@SWNTs, were explored. Morphological characteristics of C59N@SWNTs were assessed and evaluated by means of high-resolution transmission electron microscopy (HR-TEM). Pathways and ...
Luckish A - - 2008
Accumulating evidence suggests that osteoporosis and coronary artery disease have epidemiologic similarities. Moreover, the anti-atherogenic effects of bisphosphonates have been observed in vitro and in animal models. The present study investigated the effect of risedronate on indices of arterial compliance, serum osteoprotegerin (OPG) level, inflammatory and metabolic parameters in osteoporotic ...
Li Zhi-Yong - - 2008
Increased biomechanical stresses within the abdominal aortic aneurysm (AAA) wall contribute to its rupture. Calcification and intraluminal thrombus can be commonly found in AAAs, but the relationship between calcification/intraluminal thrombus and AAA wall stress is not completely described. Patient-specific three-dimensional AAA geometries were reconstructed from computed tomographic images of 20 ...
Lucats Laurence - - 2008
AIMS: Postsystolic wall thickening (PSWT) occurs after aortic valve closure. We investigated the influence of ischemia location and wall interactions on PSWT in normal and stunned myocardium. METHODS AND RESULTS: Twenty-two dogs were studied. Seven chronically instrumented dogs (sonomicrometry) underwent 10-min coronary artery occlusion (CAO) of left circumflex artery ("LCX ...
Chytilová E - - 2009
Arterial sites with low wall shear stress (WSS) are more prone to the development of atherosclerotic plaques, as was observed in carotid arteries in subjects with atherosclerosis risk factors. Type 2 diabetes mellitus (DM), hypertension, hyperlipidemia and other components of the metabolic syndrome, are associated with high risk for symptomatic ...
Ferrara A - - 2008
We present 3D finite element models of atherosclerotic arteries, used to investigate the influence of the geometry and tissue properties on the plaque rupture caused by overexpansion. We adopted a geometry reconstructed from a contiguous set of in vitro magnetic resonance images of a damaged artery. The artery wall is ...
Antonova Mariya L - - 2008
The arterial wall viscoelasticity plays an essential role in the vascular responsiveness to vasoactive drugs or pathologies. The aim of this investigation was to derive and compare resonance curve (RC), natural frequency (f(0)), dynamic modulus of elasticity (E'), and coefficient of viscosity (beta) of (i) vital and devitalized preparations of ...
Blake James R - - 2008
A simple technique to estimate the wall shear rate in healthy arteries using a clinical ultrasound scanner has been developed. This method uses the theory of fully developed oscillatory flow together with a spectral Doppler trace and an estimate of mean arterial diameter. A method using color flow imaging was ...
Sibon Igor - - 2008
OBJECT: Amine oxidases play a key role in the polymerization and cross-linking of the collagens and elastic lamellae of the arterial wall. The loss of elastic lamellae integrity is one of the first steps in the genesis of a cerebral aneurysm. The authors investigated the relation between semicarbazide-sensitive amine oxidase ...
Wilkens J L - - 2008
Lobster arteries, which exhibit non-uniform elasticity when stretched, have a trilaminar organization. The inner layer is an elastic connective tissue and the outer layer is a collagenous connective tissue; the middle layer of an artery is an aggregation of cells containing microfilaments. Arterial cells possess actin, myosin and tropomyosin. Except ...
Yamashita A - - 2008
Expansive vascular remodeling is considered a feature of vulnerable plaques. Although inflammation is upregulated in the media and adventitia of atherosclerotic lesions, its contribution to expansive remodeling is unclear. We investigated this issue in injured femoral arteries of normo- and hyperlipidemic rabbits fed with a conventional (CD group; n=20) or ...
Pezet Mylène - - 2008
Elastin, the main component of elastic fibers, is synthesized only in early life and provides the blood vessels with their elastic properties. With aging, elastin is progressively degraded, leading to arterial enlargement, stiffening, and dysfunction. Also, elastin is a key regulator of vascular smooth muscle cell proliferation and migration during ...
Black P N - - 2008
Small airways are the major site of airflow obstruction in chronic obstructive pulmonary disease (COPD). This is attributed to loss of elastin in alveoli and fibrosis in small airways. In the present study, it was hypothesised that changes to elastic fibres in alveoli might be paralleled by a similar reduction ...
Fonck, Edouard
The intent of this thesis is to study the function of elastin in cerebral arteries, its contribution into the aging process and its implication into different cerebral diseases and in particular cerebral aneurysms. As of today, little is known on the genesis, growth and rupture of cerebral aneurysm. It is ...
Gong Bin - - 2008
BACKGROUND: Using a recent model of dissecting aortic aneurysm (DAA) caused by in utero exposure to semicarbazide, we examined the elastin and collagen using standard methods and two nonlinear imaging techniques, multiphoton fluorescence (MPF) and second harmonic generation (SHG) microscopy. METHODS: Sprague-Dawley rat dams were given semicarbazide (6.13 mg/kg/day i.p.) ...
Cernes Relu - - 2008
Arterial stiffness is an independent risk factor for premature cardiovascular morbidity and mortality that can be evaluated by noninvasive methods and can be reduced by good clinical management. The present chapter examines the association between arterial stiffness and cardiovascular risk factors including hypertension, metabolic syndrome, diabetes, advanced renal failure, hypercholesterolemia ...
Tuka Vladimir - - 2008
BACKGROUND/AIMS: The feeding artery of dialysis vascular access is subjected to unusually high wall shear stress (WSS), a hemodynamic factor leading to vasodilatation, for at least several months after access creation. Physiologically, high WSS leads to compensatory endothelium-dependent vasodilatation. We supposed that the dilatation of the feeding artery continues to ...
Woodman Richard J - - 2008
Increased arterial stiffness is influenced by both functional and structural properties of the vessel wall, including changes in content of smooth muscle, elastin and collagen, reduced endothelial production of NO and increased release of endothelin-1 or AngII (angiotensin II). The RAS (renin-angiotensin) system is likely to be central to increases ...
Miyamoto Shimpei - - 2008
To perform safe anastomosis for atherosclerotic arteries, we employed a posterior-wall-first anastomotic technique with a short-thread double-needle microsuture. Between October 2005 and September 2007, we performed 17 free flap transfers to the head and neck regions with this technique. Fifteen of 17 patients had one or more risk factors for ...
Plekhanova O S - - 2008
Perivascular application of urokinase to the ballooned artery promoted the growth of neointima and constrictive remodeling of the vessel and stimulated the inflammatory response in the damaged vascular wall in vivo. Recombinant tissue plasminogen activator did not induce these changes. Our results indicate that urokinase is involved in the regulation ...
Wang Yuh-Ying Lin YY The Department of Physics, National Taiwan Normal University, Taipei, Taiwan. - - 2008
Many rehabilitation exercises involve the stretching of bodies. We point out the necessity of the longitudinal stretching in arteries. The efficiency of an arterial system is closely related to the condition of the transverse vibration of the arterial walls or to the magnitudes of the area oscillation in all blood ...
Azeloglu Evren U EU Department of Biomedical Engineering, Columbia University, New York, NY 10027, - - 2008
The arterial wall contains a significant amount of charged proteoglycans, which are inhomogeneously distributed, with the greatest concentrations in the intimal and medial layers. The hypothesis of this study is that the transmural distribution of proteoglycans plays a significant role in regulating residual stresses in the arterial wall. This hypothesis ...
Olgac Ufuk - - 2008
The work herein represents a novel approach for the modeling of low-density lipoprotein (LDL) transport from the artery lumen into the arterial wall, taking into account the effects of local wall shear stress (WSS) on the endothelial cell layer and its pathways of volume and solute flux. We have simulated ...
Laughlin M Harold MH Department of Biomedical Sciences, College of Veterinary Medicine, 1600 E. Rollins Rd., University of Missouri, Columbia, MO 65211, USA. - - 2008
Current evidence indicates that the ability of physical activity to sustain a normal phenotype of arterial endothelial cells (ECs) plays a central role in the beneficial effects of exercise (Ex) on atherosclerotic disease. Here we evaluate the strength of evidence that shear stress (SS) and/or circumferential wall stress (stretch) are ...
Abisi Said - - 2007
Cysteine proteases are potent elastolytic enzymes and together with their inhibitor, cystatin C, have been linked with the growth of abdominal aortic aneurysms (AAAs). These enzymes and their inhibitors have previously been studied in AAAs, but comparisons have always been made with wall from normal aorta. Atherosclerosis is a feature ...
Kerwin William - - 2008
The purpose of this study was to investigate whether large arteries in subjects with Ehlers-Danlos Syndrome Type IV (EDS IV) exhibit altered morphological and functional characteristics that might indicate the risk of complications. Subjects with EDS IV, an inherited disorder of type III collagen, have a significant lifetime risk of ...
Dasouki Majed - - 2007
Mutations involving elastic tissue proteins result in a broad spectrum of phenotypes affecting skin, skeleton, ocular and vascular structures, including tortuous blood vessels and cutis laxa. Here we report on a female newborn with apparently long fingers, aortic aneurysm, tortuous pulmonary arteries and mild generalized lax skin. She died at ...
Claridge Martin W - - 2008
The aim of the study was to investigate the reproducibility of estimation of Young's modulus E and pressure strain elastic modulus Ep, derived from a tissue Doppler imaging (TDI) wall motion technique. Healthy subjects had their arteries insonated at the same sitting by two different observers and at two different ...
< 5 6 7 8 9 10 11 12 13 14 15 >