Water and macromolecular transport into the walls of vessels with differing atherogenic susceptibilities.
Item
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Title
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Water and macromolecular transport into the walls of vessels with differing atherogenic susceptibilities.
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Identifier
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AAI3187390
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identifier
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3187390
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Creator
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Shou, Yixin.
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Contributor
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Mentors: David S. Rumschitzki | Kung-ming Jan
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Date
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2005
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Language
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English
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Publisher
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City University of New York.
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Subject
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Engineering, Chemical | Engineering, Biomedical
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Abstract
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Large arteries such as the aorta and the coronary arteries are atherogenic. Transendothelial transport of lipid into and its spread in the subendothelial intima of large arteries, together with its subsequent accumulation therein are believed to be the earliest steps leading to plaque formation. The pulmonary artery can develop the disease when it is under prolonged pulmonary hypertension. Veins are only disease-prone after grafting a vein as an arterial bypass. This thesis focuses on experimental studies on the water filtration, tracer transport and ultrastructures of the rat aorta, pulmonary artery and the inferior vena cava, as representatives of the three classes of large vessels, in order to understand their very different atherogenicity. In addition, we investigate the contribution of the trans-membrane water channel Aquaporin to the aortic hydraulic conductivity and propose a preliminary model for understanding the water filtration processes through the walls of the three vessels.;This thesis begins by studying the ultrastructures of the pulmonary artery (PA) and the inferior vena cava (IVC) and comparing them with that of the aorta. Using the elastin-specific stain orcein, we find that the PA has continuous endothelium and complete internal elastic lamina (IEL). Its structure is similar to that of the aorta, but has a thinner wall and fewer and thinner elastin sheets. The vein has a very different structure; it has a continuous endothelium, a very incomplete IEL, only sparse bits of elastin and considerably more collagen than the arteries.;We measure the hydraulic conductivity Lp for each vessel as a function of transmural pressure DeltaP, both with intact and denuded endothelium on the same vessel. Aortic Lp is high at 60 mmHg, drops by ∼40% at 100 mmHg and is pressure-insensitive beyond. The trends are similar in the PA and IVC, dropping 42% from 10--40 mmHg and flat to 100 mmHg for the PA and dropping 33% from 10--20 mmHg and essentially flat to 60 mmHg. Endothelial removal renders Lp(DeltaP) flat; it increases the aortic Lp by ∼75%, doubles Lp of the PA and quadruples Lp of the IVC. The specific resistance (1/Lp) of the aortic endothelium is ∼47% of the total resistance. (Abstract shortened by UMI.).
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Type
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dissertation
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Source
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PQT Legacy CUNY.xlsx
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degree
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Ph.D.
