Biomedical Engineering and Bioengineering Commons^™

Impact Of Sex On Proliferation And Maturation Of Primary Isolated Myoblasts, Elsa M. Bean

Biomedical Engineering

Peripheral arterial occlusive disease (PAOD) is caused by the buildup of atherosclerotic plaque causing restriction in blood flow in tissue, known as ischemia. It affects 8 million people in the United States and can hinder daily life through the onset of symptoms such as intermittent claudication and in extreme cases ulcers and gangrene. Surgical revascularization is not accessible to certain patient populations, such those of advanced age, highlighting a need for alternative therapies. For example, naturally occurring bypass arteries, called collateral blood vessels, can remodel and enlarge to bypass the occlusion. This process, known as arteriogenesis, has been studied as …

Impact Of Primary Myoblasts On Macrophage Polarization In-Vitro, Olivia Welch

Master's Theses

Peripheral artery disease (PAD) is characterized by the development of atherosclerotic plaques on arterial walls, leading to the narrowing of blood vessels, resulting in ischemia in the downstream tissue. In the United States, 12% of the adult population is affected by PAD and its related symptoms. Current surgical revascularization techniques can be effective in part of the patient population, but there is a need for other options. Alternatively, collateral blood vessels, or natural bypass arteries, enlarge to increase blood flow to the ischemic tissue in a process called arteriogenesis, which has been studied as a therapeutic option. Cell-based therapies, such …

Sex Differences And The Effects Of Exercise Training On Functional Vasodilation Following Arterial Occlusion In The Balb/C Mouse Spinotrapezius, Britta Nelson

Master's Theses

Peripheral arterial occlusive disease (PAOD) often presents as intermittent claudication, which may be caused by impaired vasodilation. Impairment of resistance vessels may contribute to the pathogenesis of PAOD, and explain the poor correlation between resting blood flow and limb function. Collateral function following arterial occlusion is not well defined, however collaterals and arterialized collateral capillaries (ACCs) in male and female animal models exhibit impaired vasodilation following arterial occlusion, which can potentially be improved with exercise training. Furthermore, resistance vessels in the ischemic tree and stem are likely involved in the pathogenesis of PAOD, however the relative importance of each is …

The Impacts Of Arterial Occlusion, Sex, And Exercise On Arteriogenesis And Functional Vasodilation, Megan Tze-Mei Chu

Master's Theses

The most frequent clinical presentation of peripheral arterial occlusive disease (PAOD) is intermittent claudication, which may be caused by impaired vasodilation. Patients demonstrate both local and systemic impairments in vasodilation, but as the collateral circulation is the primary site of resistance to the ischemic zone, impaired collateral vasodilation would have the greatest potential to induce claudication. Collateral function following arterial occlusion is not well defined, but immature collaterals may demonstrate impaired vasodilation in animal models, although this is potentially improved with exercise training. Furthermore, as females exhibit poorer physical function with ischemia and less improvement with therapeutic exercise, there appears …

Functional Vasodilation And Vascular Reactivity In Arteriolar Collaterals In The Spinotrapezius Of Males And Females, Britta C. Nelson

Biomedical Engineering

Peripheral arterial occlusive disease (PAOD) occurs when there is narrowing or blockage of the peripheral arteries that carry blood to the extremities, most commonly the legs. The most common symptom of PAOD is intermittent claudication, or ischemic pain during exercise. Women with PAOD experience a greater extremity functional impairment than men. Since impaired vasodilation might cause the ischemic pain from PAOD, we should evaluate vasodilation post ligation in males and females in collateral vessels, which connect two arterial segments to maintain blood flow to an otherwise hypoxic area. First, we need to examine collateral vasodilation in unoperated male and female …

The Effect Of Neurostimulation On Ischemic Pain And Methods Of Assessing Pain, Kaylee Keck

Biomedical Engineering

Peripheral arterial disease (PAD) impacts approximately eight million people in the United States [1]. Disease progression leads to chronic ischemic pain, hindering quality of life. Pharmaceuticals are a typical treatment for pain associated with PAD; but as few as 30% of patients have a significant reduction of pain (≥50%) [2].

Neurostimulation is commonly used as a treatment for various diseases and injuries, including Parkinson’s disease and sports-related back and knee injuries [2]. The objective of the study was to explore neurostimulation and its effect on pain and paresthesia for a model of acute peripheral ischemia in young college students.

Pain …

The Effects Of Transcutaneous Electrical Neurostimulation On Analgesia And Peripheral Perfusion, Leah I. Schafer

Master's Theses

Peripheral arterial occlusive disease (PAOD) affects 8 to 12 million Americans over the age of 50. As the disease progresses, arterial occlusions arising from atherosclerotic lesions inhibit normal metabolic vasodilation in the peripheries, resulting in limb ischemia and claudication. Pharmacological and surgical treatments currently used to treat both the hemodynamic and pain symptoms associated with PAOD can involve adverse and potentially life-threatening side effects. Thus, there is a need for additional innovative therapies for PAOD.

Neurostimulation has a known analgesic effect on both acute and chronic pain. Although the exact mechanisms remain under investigation, local vascular tone may be modulated …

Measuring Blood Flow In The Skeletal Muscle Microcirculation Using Laser Speckle Flowmetry, Kenneth Howard Gouin Iii

Biomedical Engineering

The presence of a native collateral circulation, which serves as a natural bypass for blood flow around an occlusion, improves prognosis for patients with ischemic diseases, such as peripheral arterial occlusive disease (PAOD). However, not all patients have a native collateral circulation, and animal models suggest a genetic basis for this variability. In mice, such as the BALB/c, that lack native arteriolar collaterals, neocollateral formation from capillaries that connect two arterial trees can occur after arterial occlusion, resulting in reperfusion of the ischemic watershed. Immature arterialized collateral capillaries (ACCs) at 7 days post arterial occlusion do not vasodilate in response …

Analysis Of Particles Thorough The Aortic Arch During Transcatheter Aortic Valve Replacement, Andrew Joseph Janicki

Master's Theses

Ischemia caused by particles becoming dislodged during transcatheter aortic valve replacement (TAVR) is a possible complication of TAVR. The particles that become dislodged can travel out of the aortic valve, into the aortic arch, and then into either the brachiocephalic artery, the left common carotid artery, the left subclavian artery or continue into the descending aorta. If the particles continue into the descending aorta it poses no risk of causing ischemia however if it travels into the other arteries then it increases the possibility of the particle causing an ischemic event. The goal of this study is to determine what …

Vascular Reactivity In Newly-Formed And Mature Arterialized Collateral Capillaries, Sara K. Hellstrom

Master's Theses

Peripheral arterial occlusive disease (PAOD) is a globally-prevalent cardiovascular disease in which atherosclerotic plaques narrow arterial lumen diameters and restrict blood flow to downstream tissues. The impact of these occlusions can be mitigated by collateral vessels that connect parallel arterial branches and act as natural bypasses to maintain perfusion. In animal models that lack collateral arterioles, capillaries that connect terminal arteriolar segments can arterialize and form functional collaterals following an ischemic event; however, in the early stages of development, vasodilation is impaired. We explored the mechanism of impaired vasodilation in arterialized collateral capillaries (ACCs) and pre-existing collaterals (PECs) by evaluating …

Investigating Hemodynamic Responses To Electrical Neurostimulation, Sean Youra

Master's Theses

Since the 1900s, the number of deaths attributable to cardiovascular disease has steadily risen. With the advent of antihypertensive drugs and non-invasive surgical procedures, such as intravascular stenting, these numbers have begun to level off. Despite this trend, the number of patients diagnosed with some form of cardiovascular disease has only increased. By 2030, prevalence of coronary heart disease is expected to increase approximately by 18% in the United States. By 2050, prevalence of peripheral arterial occlusive disease is expected to increase approximately by 98% in the U.S. No single drug or surgical intervention offers a complete solution to these …

Functional Vasodilation Is Impaired In Arterialized Capillaries In The Spinotrapezius, Joshua P. Cutts

Biomedical Engineering

Ischemic diseases are the result of atherosclerotic plaques, which occlude conduit arteries. Ischemic disease in different tissues leads to different conditions, such as coronary artery disease (CHD), cerebrovascular disease (CVD), and peripheral arterial occlusive disease (PAOD). Patient vasculature architecture is variable; some patients having many collateral vessels, which are connect one arterial branch to another, and readily serve as natural bypass routes to atherosclerotic occlusions, to enlarge and provide blood flow to tissue distal to the occlusion. Patients with many natural collateral vessels are ischemia protected. Unfortunately, not all patients have collateral arterioles to remodel into conduit vessels and provide …

The Effect Of Neurostimulation On Blood Flow And Ischemic Pain, Stacey M. Fishman

Biomedical Engineering

Chronic pain caused by lack of blood flow is known as ischemic pain. Neurostimulation, the application of electrical currents through a region of the body, is effective for pain modulation, and it is hypothesized that this can be explained by the gate control theory and alterations of the sympathetic output initiated by the metaboreflex. The decrease of sympathetic output reduces vasoconstriction and improves blood flow. Transcutaneous electrical nerve stimulation (TENS) and interferential currents (IFC) stimulation, both non-invasive neurostimulation techniques, were evaluated for their effects on cutaneous blood flow on the palm. High or low frequency TENS and/or IFC, and the …

Vascular Reactivity Of Immature Arterialized Capillaries, Sara Hellstrom

Biomedical Engineering

Peripheral arterial occlusive disease (PAOD) is a globally prevalent cardiovascular disease in which atherosclerotic plaques narrow arterial lumen diameters and restrict blood flow to down stream tissues. The impact of these occlusions can be mitigated by collateral vessels that connect parallel arterial branches and act as natural bypasses to maintain perfusion. Some patients with PAOD may not have robust collateral networks to accommodate ischemic tissues in the event of an occlusion and, therefore, may be more susceptible to hypoxia and tissue necrosis. In animal models that lack collateral arterioles, capillaries can arterialize and form functional collaterals; however, in the early …

A Mouse Model Of Aortic Endothelial Denudation And Neointimal Formation, Ashkon C. Nehzati

Biomedical Engineering

More than 385,000 people die from coronary heart disease (CHD) annually and treatment costs $108.9 billion each year including the cost of health care services, medications, and lost productivity. CHD decreases heart function by limiting oxygen and nutrient transport carried through the coronary arteries. A complete block to the coronary arteries causes a myocardial infarction in response to an elimination of blood supply to cardiomyocytes. Partial occlusion results in insufficient blood supply to cardiomyocytes, producing myocardial ischemia and angina, which are usually treated with intravascular stents deployed percutaneously, before myocardial infarction occurs. Stents are the most common ways to expand …

Ischemia Impairs Vasodilation In Skeletal Muscle Resistance Artery, Kyle Remington Struthers

Master's Theses

Functional vasodilation in arterioles is impaired with chronic ischemia. We sought to examine the impact of chronic ischemia and age on skeletal muscle resistance artery function. To examine the impact of chronic ischemia, the femoral artery was resected from young (2-3mo) and adult (6-7mo) mice and the profunda femoris artery diameter was measured at rest and following gracilis muscle contraction 14 days later using intravital microscopy. Functional vasodilation was significantly impaired in ischemic mice (14.4±4.6% vs. 137.8±14.3%, p<0.0001 n=8) and non-ischemic adult mice (103.0±9.4% vs. 137.8±14.3%, p=0.05 n=10). In order to analyze the cellular mechanisms of the impairment, a protocol was developed to apply pharmacological agents to the experimental preparation while maintaining tissue homeostasis. Endothelial and smooth muscle dependent vasodilation were impaired with ischemia, 39.6 ± 13.6% vs. 80.5 ± 11.4% and 43.0 ± 11.7% vs. 85.1 ± 10.5%, respectively. From this data, it can be supported that smooth muscle dysfunction is the reason for the observed impairment in arterial vasodilation.

Immunohistochemical Mapping Of Hypoxia In Ischemic Mouse Hindlimb Skeletal Muscle, Emily Deckert

Biomedical Engineering

The study of blood vessel growth and remodeling is a complex endeavor. Hypoxia, the lack of oxygen in a tissue, is known to stimulate angiogenesis (the growth of new blood vessels), and have little effect on arteriogenesis (the enlargement of existing blood vessels). However, the role of hypoxia in vessel function is unknown, but may be determined using the results and methods developed in this experiment.

Supplied by the bloodstream, oxygen is required by all cells and tissues to remain healthy. If the bloodstream supplying a certain tissue with blood is disrupted, the tissue becomes ischemic, often leading to hypoxia. …