Search Results
Results 401 - 450 of 1720
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Wiernicki I - - 2008
BACKGROUND: The natural history of abdominal aortic aneurysm (AAA) is wall remodelling potentially leading to a final rupture. The pathogenesis of AAA appears to be multifactorial. The aim of this pilot prospective study was to assess the relationship between the thickness of the thrombus within the abdominal aortic aneurysm, intramural ...
Caro C G - - 2009
The suggestion was made in the 1870s that mechanical irritation of the arterial wall is a cause of atherosclerosis, because the changes were chiefly found at points "exposed to the full stress and impact of the blood." The mechanical damage theory persisted until well into the 20th century when, with ...
Cheng Chao-Hung - - 2009
AIMS: Glucose transporter 10 (GLUT10), encoded by the SLC2A10 gene, is a member of the class III facilitative glucose transporter family. Mutations in the SLC2A10 gene cause arterial tortuosity syndrome (ATS) in humans. To further study the pathogenesis of the disease, we generated mice carrying GLUT10 mutations. METHODS AND RESULTS: ...
Thijssen Dick H J - - 2009
Flow-mediated dilatation (FMD) has become a commonly applied approach for the assessment of vascular function and health in humans. Recent studies emphasize the importance of normalizing the magnitude of FMD to its apparent eliciting stimulus, the postdeflation arterial shear. However, the relationship between shear stress and the magnitude of FMD ...
Gundiah Namrata - - 2009
Uniaxial mechanical experiments have shown that a neo-Hookean/Gaussian model is suitable to describe the mechanics of arterial elastin networks [Gundiah, N., Ratcliffe, M.B., Pruitt, L.A., 2007. Determination of strain energy function for arterial elastin: Experiments using histology and mechanical tests. J. Biomech. 40, 586-594]. Based on the three-dimensional elastin architecture ...
Renner-Martin T F P - - 2009
Although donkeys play an important role as companion or pack and draught animals, theriogenological studies and anatomical data on the genital organs of the jenny are sparse. To provide anatomical descriptions and morphometric data, the organa genitalia feminina, their arteries and the ligamentum latum uteri of 10 adult but maiden ...
Macedo Robson - - 2008
To evaluate the use of coronary wall MRI as a measure of atherosclerotic disease burden in an asymptomatic population free of clinical cardiovascular disease. Coronary wall magnetic resonance imaging (MRI) is a noninvasive method for evaluation of arterial wall remodeling associated with atherosclerosis. Asymptomatic participants of the Multi-Ethnic Study of ...
Kouhi E - - 2008
A three-dimensional (3D) computational model of stenotic coronary artery bypass grafting (CABG) system with fluid-structure interaction (FSI) using realistic physiological conditions is introduced. Unsteady pulsatile blood flow is applied to the wall of non-linear deformable arteries over the systolic period. In the analysis, the arbitrarily Lagrangian-Eulerian (ALE) formulation is used ...
Nain S - - 2009
This study examined the putative role of blood vessel pathology in the development of ascites in broilers. Major blood vessels (aorta, brachiocephalic arteries, pulmonary arteries, and vena cava) from normal commercial male broiler chickens, and broilers that developed congestive heart failure (CHF) with or without ascites were subjected to gross ...
Lee Yong-Ung YU Department of Mechanical Engineering, University of Texas at San Antonio, 1 UTSA Circle, San Antonio, TX 78249, - - 2008
Arteries in vivo are subjected to large longitudinal stretch, which changes significantly due to vascular disease and surgery. However, little is known about the effect of longitudinal stretch on arterial endothelium. The aim of this study was to determine the morphologic adaptation of arterial endothelial cells (ECs) to elevated axial ...
Arribas Silvia M - - 2008
Elastin is a major component of conduit arteries and a key determinant of vascular viscoelastic properties. Aberrant organization of elastic lamellae has been reported in resistance vessels from spontaneously hypertensive rats (SHR) before the development of hypertension. Hence, we have characterized the content and organization of elastic lamellae in conduit ...
Kroon Martin - - 2008
Saccular aneurysm growth in a human middle cerebral artery is modeled. The aneurysm growth model was presented in a companion paper by Kroon and Holzapfel ("A Model for Saccular Cerebral Aneurysm Growth by Collagen Fibre Remodelling," J. Theor. Biol., in press) and was assessed there for axisymmetric growth. The aneurysm ...
Richardson Richard B - - 2008
PURPOSE: The aim is to assess the change with age and disease of the oxygen concentration within the coronary artery walls. MATERIALS AND METHODS: In an accompanying paper, Part A, the age-dependent morphology and composition for the wall layers of normal and diseased coronary arteries were developed from published data. ...
Richardson Richard B - - 2008
PURPOSE: The aim is to study the implications of the decrease in oxygen concentration in the coronary artery walls with age and atherosclerosis, particularly with regard to an associated reduction in the radiosensitivity to high-and low-linear-energy-transfer (LET) irradiation. MATERIALS AND METHODS: In accompanying papers, the age-dependent morphology and composition for ...
Boyd J - - 2008
Near-wall shear is known to be important in the pathogenesis and progression of atherosclerosis. In this paper, the shear field in a three-dimensional model of the human carotid artery is presented. The simulations are performed using the lattice Boltzmann model and are presented at six times of interest during a ...
Isaksen Jørgen Gjernes - - 2008
BACKGROUND AND PURPOSE: Cerebral artery aneurysms rupture when wall tension exceeds the strength of the wall tissue. At present, risk-assessment of unruptured aneurysms does not include evaluation of the lesions shape, yet clinical experience suggests that this is of importance. We aimed to develop a computational model for simulation of ...
Krishnamoorthy Mahesh K - - 2008
Venous stenosis is a significant problem in arteriovenous fistulae, likely due to anatomical configuration and wall shear stress profiles. To identify linkages between wall shear stress and the magnitude and pattern of vascular stenosis, we produced curved and straight fistulae in a pig model. A complete wall stress profile was ...
Kim Young-Ho - - 2008
The influence of wall motion on the hemodynamic characteristics of the human femoral bifurcation and its effects on the development of peripheral artery disease has not been previously investigated. This study aimed in investigating the hemodynamics of a compliant patient-specific femoral artery bifurcation model by a fluid structure interaction (FSI) ...
Sung Si Chan - - 2009
The growth potential of the neoaorta after the stage I Norwood procedure could be limited when the patient has a small ascending aorta. Patients with hypoplastic left heart syndrome usually have a large main pulmonary artery (MPA) and from its posterior wall both pulmonary arteries arise. We describe a modified ...
Debrah, Dan Onwona
Relaxin is a peptide hormone emanating from the corpus luteum of the ovary which circulates during pregnancy. Traditionally, the hormone has been associated with female reproductive processes but recent evidence has suggested relaxin may play a vital role in regulating renal and cardiovascular function. Analogous to pregnancy, chronic administration of ...
Shifren Adrian - - 2008
Elastin is a major structural component of large elastic arteries and a principal determinant of arterial biomechanical properties. Elastin loss-of-function mutations in humans have been linked to the autosomal-dominant disease supravalvular aortic stenosis, which is characterized by stenotic lesions in both the systemic and pulmonary circulations. To better understand how ...
Atkinson Jeffrey - - 2008
With age, the calcium content of the arterial wall increases. Calcification occurs at two main levels: intimal plaques and the medial elastic fiber network. The latter has been referred to as medial elastocalcinosis and is the subject of this review. The mechanisms involved in elastocalcinosis are complex and involve polar, ...
Boussel Loic L Department of Radiology, VA Medical Center, San Francisco, USA 94121, USA. - - 2008
Evolution of intracranial aneurysmal disease is known to be related to hemodynamic forces acting on the vessel wall. Low wall shear stress (WSS) has been reported to have a negative effect on endothelial cells normal physiology and may be an important contributor to local remodeling of the arterial wall and ...
Cai Weijun - - 2008
Patients with occlusive atherosclerotic vascular diseases have frequently developed collateral blood vessels that bypass areas of arterial obstructions. The growth of these collateral arteries has been termed "arteriogenesis" which describes the process of a small arteriole's transformation into a much larger conductance artery. In recent years, intensive investigations using various ...
Bonnier Franck - - 2008
The advent of moderate dilatations in ascending aortas is often accompanied by structural modifications of the main components of the aortic tissue, elastin and collagen. In this study, we have undertaken an approach based on FTIR microscopy coupled to a curve-fitting procedure to analyze secondary structure modifications in these proteins ...
Zeng Dehong - - 2008
A computational model incorporating physiological motion and uniform transient wall deformation of a branchless right coronary artery (RCA) was developed to assess the influence of artery compliance on wall shear stress (WSS). Arterial geometry and deformation were derived from modern medical imaging techniques, whereas the blood flow was solved numerically ...
Casella Ivan Benaduce - - 2008
To describe and test a practical protocol to measure common carotid intima-media thickness that uses the combined values of two longitudinal examination angles to increase sensitivity. Between February and September 2005, 206 patients underwent duplex scan examination of carotid vessels, and the intima-media thickness of 407 common carotids were measured ...
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 ...
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