Image Quality Of Energy-Dependent Approaches For X-Ray Angiography, Jesse Evan Tanguay

Electronic Thesis and Dissertation Repository

Digital subtraction angiography (DSA) is an x-ray-based imaging method widely used for diagnosis and treatment of patients with vascular disease. This technique uses subtraction of images acquired before and after injection of an iodinated contrast agent to generate iodine-specific images. While it is extremely successful at imaging structures that are near-stationary over a period of several seconds, motion artifacts can result in poor image quality with uncooperative patients and DSA is rarely used for coronary applications.

Alternative methods of generating iodine-specific images with reduced motion artifacts might exploit the energy-dependence of x-ray attenuation in a patient. This could be performed …

Vascular Stem Cells In Diabetic Complications, Emily C. Keats

Electronic Thesis and Dissertation Repository

Diabetes leads to a variety of secondary complications. At the heart of these complications lies endothelial cells (ECs) – cells that take up unregulated plasma glucose, experience various biochemical alterations, and provide the basis for whole organ vascular dysfunctions. With the purpose of generating new vascular networks for the treatment of these chronic complications, my initial work focused on vascular stem cells (VSCs). VSCs have the ability to differentiate into both endothelial (EPC) and mesenchymal (MPC) progenitor cells, both of which are necessary for the creation of stable and functional blood vessels. To establish whether these progenitor populations retain their …

Role Of Inos In Septic Pulmonary Microvascular Endothelial Cell Activation, Zahra Asad

Electronic Thesis and Dissertation Repository

Abstract

Background. Neutrophils and nitric oxide (NO) derived from inducible NO synthase (iNOS) contributes importantly to the pathophysiology of acute lung injury (ALI) and pulmonary microvascular endothelial cell (PMVEC) injury. However, the mechanism of neutrophil and neutrophil iNOS dependent PMVEC injury has not been addressed. In our studies, we assessed PMVEC activation under septic conditions, and defined the role of PMVEC vs. bone-marrow polymorphonuclear leukocytes (PMN) iNOS in this septic PMVEC activation.

Methods and Results. We isolated PMVEC from iNOS+/+ and iNOS-/- mice lungs magnetically by microbeads attached to anti-PECAM antibodies, sorted by flow cytometry (FACS) by DiI-acetylated low density …

Effects Of Niacin In Human Vascular Endothelial Cells During Lipotoxicity, Jennifer M. Hughes-Large

Electronic Thesis and Dissertation Repository

Nicotinic acid (NA) can improve vascular function and regeneration independent of correcting dyslipidemia. NA, as a potential biosynthetic precursor for NAD⁺, may elicit these vascular benefits through SIRT-mediated NAD⁺-dependent responses. We hypothesized that NA improves endothelial cell function under lipotoxic conditions through NAD⁺-dependent pathways. Angiogenic function in excess palmitate was assessed by tube formation assay following treatment of human microvascular endothelial cells (HMVEC) with NA or nicotinamide mononucleotide (NMN; a direct NAD⁺ precursor). Both NA and NMN improved HMVEC angiogenic function during palmitate overload. Only NMN increased cellular NAD⁺ and SIRT1 activity, …

Causes Of Post Stroke Falls Along The Care Continuum: Implications For Improving Patient Safety, Mona Madady

Electronic Thesis and Dissertation Repository

In Western countries stroke is responsible for 10-12% of all deaths. In 2000, strokes cost $3.6 billion for the Canadian healthcare system and lost productivity due to premature death and long-term disability. Falls are a frequent occurrence at all stages of post-stroke recovery and can have significant negative impacts. While information about the incidence and risk factors of falling among stroke survivors is available, considerably less is known about the specific factors contributing to falls and the circumstances surrounding these adverse events. The purpose of this project was to identify similarities between systemic factors of falls in stroke survivors across …

Regulation Of Lipid Homeostasis, Inflammatory Signalling And Atherosclerosis By The Peroxisome Proliferator-Activated Receptor Delta, Lazar A. Bojic

Electronic Thesis and Dissertation Repository

The peroxisome proliferator-activated receptor (PPAR) δ is a ligand-dependent transcription factor that has been implicated in metabolic and inflammatory regulation. The molecular and physiological mechanisms by which PPARδ activation regulates lipid metabolism, inflammatory signaling and protection from atherosclerosis in states of metabolic disturbance such as insulin resistance and dyslipidemia, were investigated in a series of in vitro and in vivo studies. In vitro experiments demonstrated that PPARδ activation inhibits atherogenic lipoprotein-induced lipid accumulation and the associated proinflammatory responses. The primary mechanisms for these effects were increased fatty acid β-oxidation, decreased lipoprotein lipase (LPL) activity, reduced MAPK signaling and improved insulin …

Genetic Approaches To Studying Complex Human Disease, Joseph B. Dube

Electronic Thesis and Dissertation Repository

Common, complex diseases such as cardiovascular disease (CVD) represent an intricate interaction between environmental and genetic factors and now account for the leading causes of mortality in western society. By investigating the genetic component of complex disease etiology, we have gained a better understanding of the biological pathways underlying complex disease and the heterogeneity of complex disease risk. However, the development of high throughput genomic technologies and large well-phenotyped multi-ethnic cohorts has opened the door towards more in-depth and trans-disciplinary approaches to studying the genetics of complex disease pathogenesis. Accordingly, we sought to investigate select complex traits and diseases using …