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Results 301 - 350 of 1743
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Crapo Peter M PM Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology, Atlanta, GA 30332, USA. - - 2010
Compliance mismatch is a significant challenge to long-term patency in small-diameter bypass grafts because it causes intimal hyperplasia and ultimately graft occlusion. Current engineered grafts are typically stiff with high burst pressure but low compliance and low elastin expression. We postulated that engineering small arteries on elastomeric scaffolds under dynamic ...
Yang Feng-Yi - - 2009
Continuous high-intensity focused ultrasound (HIFU) at various intensities has been shown to induce functional changes in arteries. The objective of the current study was to investigate the functional changes in arteries when pulsed HIFU is used at various acoustic power levels. Sonication was applied at an ultrasound frequency of 1 ...
Han Hai-Chao - - 2009
The stability of blood vessels under the lumen blood pressure is essential to the maintenance of normal arterial function. Buckling equations have been established recently for linear and nonlinear elastic artery models with assumed sinusoidal mode shapes. However, the theoretical base for the assumption is not clear. This study established ...
Souza Joyce G R - - 2009
Angiostrongylus lenzii n. sp. (Nematoda: Metastrongyloidea) is described and illustrated from the pulmonary artery of the wild rodent Akodon montensis Thomas, 1913, collected in the municipality of Teresopólis, Rio de Janeiro State, Brazil. It represents the 17th species of the genus and the 2nd in South America as parasites in ...
Hogan Benjamin M - - 2009
The development of arteries, veins and lymphatics from pre-existing vessels are intimately linked processes controlled by a number of well-studied reiteratively acting signalling pathways. To delineate the mechanisms governing vessel formation in vivo, we performed a forward genetic screen in zebrafish and isolated the mutant expando. Molecular characterisation revealed a ...
Nakamura Ryuji - - 2009
Arterial mechanical impedance is a characteristic of arterial dynamics that is determined by photoplethysmographic amplitude and direct arterial pressure, while mechanical impedance is indicated by stiffness, viscosity, and inertia. We compared the parameters of mechanical impedance and photoplethysmographic amplitude to estimate the magnitude of stress response in patients undergoing general ...
Hernandez-Garcia Luis L Functional MRI Laboratory, University of Michigan, Ann Arbor, Michigan 48109-2108, USA. - - 2009
Cerebral blood flow-dependent phase differences between tagged and control arterial spin labeling images are reported. A biophysical model is presented to explain the vascular origin of this difference. Arterial spin labeling data indicated that the phase difference is largest when the arterial component of the signals is preserved but is ...
Cardamone L L Dipartimento di Ingegneria Civile, Università degli Studi di Salerno, Fisciano, - - 2009
The structural protein elastin endows large arteries with unique biological functionality and mechanical integrity, hence its disorganization, fragmentation, or degradation can have important consequences on the progression and treatment of vascular diseases. There is, therefore, a need in arterial mechanics to move from materially uniform, phenomenological, constitutive relations for the ...
Cousin Maud - - 2010
Angiotensin II is a potent growth factor involved in arterial wall homeostasis. In resistance arteries, chronic increases in blood flow induce a rise in diameter associated with arterial wall hypertrophy. Nevertheless, the role of angiotensin II in this remodeling is unknown. We investigated the effect of blocking angiotensin II production ...
van der Giessen Alina G - - 2010
Wall shear stress, the force per area acting on the lumen wall due to the blood flow, is an important biomechanical parameter in the localization and progression of atherosclerosis. To calculate shear stress and relate it to atherosclerosis, a 3D description of the lumen and vessel wall is required. We ...
Krous Henry F HF Department of Pathology, Rady Children's Hospital-San Diego, CA 92123, USA. - - 2009
Previous studies addressing pulmonary artery morphology have compared cases of sudden infant death syndrome (SIDS) to controls but none have compared demographic profiles, exposure to potentially hypoxic risk factors and other pathologic variables in SIDS cases grouped according to pulmonary artery medial smooth muscle thickness. To compare the relative medial ...
Schmid H - - 2010
Recent experimental and computational studies have shown that transmurally heterogeneous material properties through the arterial wall are critical to understanding the heterogeneous expressions of constituent degrading molecules. Given that expression of such molecules is thought to be intimately linked to local magnitudes of stress, modelling the transmural stress distribution is ...
Scuteri Angelo - - 2010
We evaluated whether specific clusters of metabolic syndrome (MetS) components differentially impact on arterial structure and function, and whether the impact is similar in men and in women. Components of the MetS and arterial properties were assessed in 6148 subjects, aged 14-102 in a cluster of four towns in Sardinia, ...
Oda Shinichiro - - 2010
OBJECTIVES: Reliable suture line hemostasis should improve the outcome of aortic surgery. We examined the hemostatic effect and the tissue response of a novel elastomeric surgical sealant. METHODS: Using porcine internal carotid arteries, we performed 16 end-to-end anastomoses with four stitches of simple interrupted sutures under full heparinization. The anastomoses ...
Troidl Kerstin - - 2009
Previous studies showed that targeted eNOS disruption in mice with femoral artery occlusion does not impede - and transgenic eNOS over-expression does not stimulate - collateral artery growth following femoral artery occlusion, suggesting that NO from eNOS does not play a role in arteriogenesis. However, pharmacological NOS inhibition with L-NAME ...
Kanbay Mehmet - - 2010
Patients with end-stage renal disease treated by chronic dialysis have an impressive mortality, which more than half of this mortality is attributable to cardiovascular disease. Despite stratification for sex, race, and the presence of diabetes, cardiovascular disease mortality is 10-30 times higher in dialysis patients compared to general population. In ...
Xu X Y - - 2010
BACKGROUND: Functional imaging using positron emission tomography (PET) showed increased metabolic activities in the aneurysm wall prior to rupture, whereas separate studies using finite element analysis techniques found the presence of high wall stresses in aneurysms that subsequently ruptured. This case series aimed to evaluate the association between wall stress ...
Vriens Dennis - - 2009
For the quantification of dynamic (18)F-FDG PET studies, the arterial plasma time-activity concentration curve (APTAC) needs to be available. This can be obtained using serial sampling of arterial blood or an image-derived input function (IDIF). Arterial sampling is invasive and often not feasible in practice; IDIFs are biased because of ...
Witter Kirsti - - 2010
Tissue glues are used during surgical treatment of acute aorta dissection although some glues release toxic products and thus alter the histological structure of the vessel wall. The aim of our study was to use a porcine experimental model of infrarenal aorta dissection to compare histological changes of the vessel ...
van den Akker Jeroen - - 2010
Blood flow regulation by small arteries and arterioles includes adaptation of both vascular tone and structure. It is becoming clear that tone and remodeling of resistance vessels are highly interrelated. Indeed, concepts pointing to continuous resistance artery adaptation and plasticity are emerging. The purpose of this review is to summarize ...
Klein Andrew J - - 2009
BACKGROUND: The unique physical forces exerted on the femoropopliteal (FP) artery during movement have been implicated in the high rates of restenosis and stent fracture in this artery. Conformational changes in the FP artery during movement are important surrogates of these forces. This study sought to quantify the conformational change ...
Park Ji Kang - - 2009
In this study, we evaluated the wall of saccular cerebral aneurysms (SCAs) using two-dimensional double inversion recovery black-blood sequence (BBDI). We examined 14 patients with an unruptured SCA (USCA). The BBDI was peripheral-pulse gated, and was acquired during the mid-diastolic period. We evaluated whether the aneurysmal wall could be visualized ...
Cohn Jay N - - 2009
Noninvasive evaluation of the health of the vasculature is an increasingly important approach to identifying individuals at risk for cardiovascular morbid events. Vascular health assessment involves functional and structural examination of the large and small arteries. Endothelial dysfunction, which alters small artery function, is a key contributor to progressive structural ...
Matthews Peter B - - 2009
BACKGROUND AND AIM OF THE STUDY: Pulmonary autograft dilation can lead to aortic insufficiency requiring reoperation. Remodeling occurs when the pulmonary root is subjected to systemic pressure. It is unknown whether a regional variability of the material properties exists within the root, resulting in unequally distributed wall stress prior to ...
Yazici Ilker - - 2009
In this article, we present the use of triangulation for end-to-side microvascular arterial anastomosis. The classic end-to-side anastomosis starts by putting 2 sutures 180 degrees apart to the lateral arteriotomy aperture that is parallel to the longitudinal axis. We are performing triangulation in end-to-side microvascular artery anastomoses by putting 3 ...
Wang Chong C Robert M. Berne Cardiovascular Research Center, University of Virginia, Charlottesville, 22908, - - 2009
The stress distribution in the vessel wall has an important bearing on vascular function in health and disease. We studied the relationship between the transmural stress distribution and the opening angle (OA) to determine the stress gradient. The simulation of wall stress was based on transmural measurements of strain and ...
Chen Henry Y HY Weldon School of Biomedical Engineering, Purdue University, West Lafayette, IN 47907, - - 2010
Vascular cross-clamping is applied in many cardiovascular surgeries such as coronary bypass, aorta repair and valve procedures. Experimental studies have found that clamping of various degrees caused damage to arteries. This study examines the effects of popular clamps on vessel wall. Models of the aorta and clamp were created in ...
Massey Philip G PG University of Washington, Seattle, WA 98195-7710, - - 2009
Urokinase-type plasminogen activator (uPA) is expressed at increased levels in stenotic, atherosclerotic human arteries. However, the biological roles of uPA in the artery wall are poorly understood. Previous studies associate uPA with both acute vasoconstriction and chronic vascular remodeling and attribute uPA-mediated vasoconstriction to the kringle - not the catalytic ...
Kawasaki Toshihiro - - 2009
OBJECTIVE: The elastic properties of the carotid arterial wall have not been directly characterized in the clinical setting. Strain rate (SR) imaging is a newly developed echocardiographic method developed for imaging the tissue motion of the myocardium. The purpose of this study was to directly estimate the elastic properties of ...
Bjarnegård Niclas - - 2010
The normal aging process of the brachial artery (BA) wall is of specific interest since it is often selected as a model artery in studies of vascular function. With echo-tracking ultrasound, diameter, absolute diameter change, and intima-media thickness (IMT) were registered in 60 healthy subjects, 21-86 yr (30 men), at ...
Karmonik C - - 2010
PURPOSE: The quantification of wall motion in cerebral aneurysms is of interest for the assessment of aneurysmal rupture risk, for providing boundary conditions for computational simulations and as a validation tool for theoretical models. MATERIALS AND METHODS: 2D cine phase contrast magnetic resonance imaging (2D pcMRI) in combination with quantitative ...
Horiguchi Masahito - - 2009
Great arteries, as well as lungs and skin, contain elastic fibers as important components to maintain their physiological functions. Although recent studies have revealed that a glycoprotein fibulin-4 (FBLN4) is indispensable for the assembly of mature elastic fibers, it remains to be elucidated how FBLN4 takes part in elastogenesis. Here, ...
Carta Luca L Department of Pharmacology and Systems Therapeutics, Mount Sinai School of Medicine, New York, NY 10029, - - 2009
Even though elastin and fibrillin-1 are the major structural components of elastic fibers, mutations in elastin and fibrillin-1 lead to narrowing of large arteries in supravalvular aortic stenosis and dilation of the ascending aorta in Marfan syndrome, respectively. A genetic approach was therefore used here to distinguish the differential contributions ...
Wang Susanna S SS Department of Human Genetics, UCLA David Geffen School of Medicine, Los Angeles, CA, - - 2009
Disruption of the elastic lamina, as an early indicator of aneurysm formation, and vascular calcification frequently occur together in atherosclerotic lesions of humans. We now report evidence of shared genetic basis for disruption of the elastic lamina (medial disruption) and medial calcification in an F(2) mouse intercross between C57BL/6J and ...
Zhao Yilin - - 2010
Alternatives to using native arteries in vascular surgery are urgently needed. Vessels made from synthetic polymers have shortcomings such as thrombosis, rejection, intimal hyperplasia, calcification, infection, chronic inflammation and no growth potential. Tissue-engineered blood vessels (TEBV) may overcome these problems. We developed a tissue-engineered artery using autologous bone marrow derived ...
Thacher Tyler - - 2009
Cyclic circumferential stretch and shear stress act in concert and yet are capable of independently mediating arterial smooth muscle function, modulating the production of superoxide and stimulating arterial remodeling. Porcine carotid arteries were perfused ex vivo for 72 h. Groups combining normal (5%) and reduced (1%) stretch with high shear ...
Gonzalez Magdalena - - 2009
Vascular calcification is caused by the deposition of basic calcium phosphate crystals in blood vessels, myocardium, and/or cardiac valves. Calcification decreases artery wall compliance, and arterial calcification is associated to mortality in hyperphosphatemic renal failure and diabetes mellitus. The calcification of the tunica media characterizes the arteriosclerosis observed with age, ...
Rachev Alexander - - 2009
Organ culture systems are used to study remodeling of arteries and to fabricate tissue engineered vascular grafts. Investigations to date focused on changes in geometry and mechanical response of arteries or constructs associated with controlled sustained alterations in the global load parameters such as the arterial pressure, flow, or axial ...
Collette Mathieu - - 2009
PURPOSE: Stiffness of the large arteries (e.g., aorta) plays an important role in the pathogenesis of cardiovascular diseases. To date, the reference method for the determination of regional arterial stiffness is the measurement of the carotid-femoral pulse wave velocity (PWV) by tonometric techniques. However, this method suffers from several drawbacks ...
Eriksson Thomas - - 2009
A model for saccular cerebral aneurysm growth, proposed by Kroon and Holzapfel (2007, "A Model for Saccular Cerebral Aneurysm Growth in a Human Middle Cerebral Artery," J. Theor. Biol., 247, pp. 775-787; 2008, "Modeling of Saccular Aneurysm Growth in a Human Middle Cerebral Artery," ASME J. Biomech. Eng., 130, p. ...
Masugata Hisashi - - 2009
Large vessel vasculitis leads to arterial wall thickening and stiffening because of chronic inflammatory changes. The cardio-ankle vascular index (CAVI) is recently utilized for assessing arterial stiffening caused by atherosclerosis-related diseases, including hypertension and diabetes, as well as aging. CAVI is mathematically calculated from stiffness index beta, which is established ...
Watton Paul N - - 2009
The physiological mechanisms that give rise to the inception and development of a cerebral aneurysm are accepted to involve the interplay between the local mechanical forces acting on the arterial wall and the biological processes occurring at the cellular level. In fact, the wall shear stresses (WSSs) that act on ...
Trachet Bram - - 2009
In this paper, the influence of the aortic dimensions of an investigated mouse on its resulting wall shear stress (WSS) was studied. A numerical model of a mouse aortic arch was created based on a micro-CT scan of a vascular corrosion cast of an 8-week-old wild type mouse. This model ...
Van Epps J Scott JS Department of Surgery, McGowan Institute for Regenerative Medicine, Center for Vascular Remodeling and Regeneration, University of Pittsburgh, PA 15219, - - 2009
Certain arteries (e.g., coronary, femoral, etc.) are exposed to cyclic flexure due to their tethering to surrounding tissue beds. It is believed that such stimuli result in a spatially variable biomechanical stress distribution, which has been implicated as a key modulator of remodeling associated with atherosclerotic lesion localization. In this ...
Chuang Ting-Hsien TH Department of Bioengineering, Clemson University, Clemson, South Carolina 29634, - - 2009
Tissue-engineered vascular grafts require elastic, acellular porous scaffolds with controlled biodegradability and properties matching those of natural arteries. Elastin would be a desirable component for such applications, but elastin does not easily regenerate experimentally. Our approach is to develop tubular elastin scaffolds using decellularization and removal of collagen from porcine ...
Ke Xue Dan - - 2010
Pathological levels of homocysteine induce a dramatic degradation of arterial elastic structures. This severe metalloproteinase-dependant elastolysis affects elastic structures all over the media suggesting that smooth muscle cells (SMC) may participate to this process induced by homocysteine. Therefore, we investigated the effect of physiological (10 microM) and pathological (50, 100, ...
Myredal Anna - - 2010
Ultrabiomicroscopy is a novel high-frequency (55 MHz) ultrasound technique that could be used to non-invasively measure the vessel wall and separate the intima-media complex into measurements of intima and media thickness. Since no previous study has measured intima and media thickness separately in vivo in patients with coronary heart disease ...
Valentín A A Department of Biomedical Engineering, 337 Zachry Engineering Center, 3120 TAMU, Texas A&M University, College Station, TX 77843-3120, - - 2009
Evolving constituent composition and organization are important determinants of the biomechanical behaviour of soft tissues. In arteries, vascular smooth muscle cells and fibroblasts continually produce and degrade matrix constituents in preferred modes and at altered rates in response to changing mechanical stimuli. Smooth muscle cells similarly exhibit vasoactive changes that ...
Jeffcoate W J - - 2009
Calcification of the media of arterial walls is common in diabetes and is particularly associated with distal symmetrical neuropathy. Arterial calcification also complicates chronic kidney disease and is an independent risk factor for cardiovascular and all-cause mortality. The term calcification is not strictly accurate because the morphological changes incorporate those ...
Miller Steven J - - 2010
Aging is a major risk factor for the development of cardiovascular diseases, including arterial occlusive disease. Oxidant stress increases with age, and may be a significant factor contributing to vascular dysfunction and disease. We have shown that aging and hypertension impair collateral growth, the natural compensatory response to arterial occlusive ...
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