Medicine and Health Sciences Commons^™

Spontaneous Coronary Artery Dissection, Amy N. Wagner

Graduate Dissertations and Theses

Spontaneous coronary artery dissection (SCAD) causes 35% of myocardial infarctions in women under the age of 50 years old. Typically, these are healthy, active women without risk factors for atherosclerotic coronary artery syndromes. SCAD is a myocardial infarction caused by a coronary arterial dissection and not atherosclerotic plaques. Because of this, those effected do not present with the typical risk factors associated with acute atherosclerotic coronary syndromes. Therefore, clinicians must maintain a high level of suspicion for SCAD in young, healthy, women presenting with chest pain. Observation and pharmacological therapies are the preferred methods of treatment for a SCAD event. …

Engineering Advanced Micro And Nanofiber Materials For Biomedical Applications, Alec D. Mccarthy

Theses & Dissertations

At the functional crossroads of engineering and biomedical sciences lies the interdisciplinary field of biomedical engineering. Principles of biomedical engineering are vast, and the rigorous application of engineering towards clinically-relevant medicine has the ability to take novel concepts from bench to bedside. Arguably one of the most promising and productive sub-fields within the biomedical engineering discipline is biomaterial engineering. Here, novel biomaterials, synthesized from natural, synthetic, or hybrid materials, can be used in tissue repair and regeneration, hemostasis, as anatomical support and drug delivery vessels, or as diagnostic devices.

Of particular interest are applications of nanofiber and microfiber objects, which …

Evaluation Of Stratified Antibiograms For Use In Laboratory And Antimicrobial Stewardship, Linsey Donner

Theses & Dissertations

Antibiograms are critical for choosing empiric antimicrobial therapy. Cumulative antibiograms, which aggregate susceptibility data, can mask differences within specific patient subsets or clinical syndromes. This dissertation was done to determine if antibiotic susceptibilities showed substantial differences when comparing stratified antibiograms to cumulative antibiograms.

Antibiotic susceptibility data was retrospectively obtained from Nebraska Medicine January 1, 2017 – December 31, 2019 for Escherichia coli, Pseudomonas aeruginosa, Klebsiella pneumoniae, Staphylococcus aureus, and Enterococcus faecalis. The University of Nebraska Medical Center’s web antibiogram clinical decision support tool was used to export the data. Bacteria-antibiotic susceptibility rates of stratified antibiograms …

Mapping Neural Responses Onto Innate And Acquired Behavior: From Insect Olfaction To Realizing A Bio-Hybrid Chemical Recognition System, Rishabh Chandak

McKelvey School of Engineering Theses & Dissertations

In many organisms, the sense of smell, driven by the olfactory system, serves as the primary sensory modality that guides a plethora of behaviors such as foraging for food, finding mates, and evading predators. Using an array of biological sensors, the olfactory system converts volatile chemical inputs from an organism’s environment into well-patterned neural responses that inform downstream motor neurons to drive appropriate behaviors (e.g., moving towards food or away from danger). For many external cues, the elicited neural responses are often determined by the genetic makeup of the organism, which assigns an innate preference, or valence, for these different …

An Investigation Of Sensory Percepts Elicited By Macro-Sieve Electrode Stimulation Of The Rat Sciatic Nerve, Nikhil Shiva Chandra

McKelvey School of Engineering Theses & Dissertations

Intuitive control of conventional prostheses is hampered by their inability to replicate the rich tactile and proprioceptive feedback afforded by natural sensory pathways. Electrical stimulation of residual nerve tissue is a promising means of reintroducing sensory feedback to the central nervous system. The macro-sieve electrode (MSE) is a candidate interface to amputees’ truncated peripheral nerves whose unique geometry enables selective control of the complete nerve cross-section. Unlike previously studied interfaces, the MSE’s implantation entails transection and subsequent regeneration of the target nerve. Therefore, a key determinant of the MSE’s suitability for this task is whether it can elicit sensations at …

The Role Of Neuronal Atp-Sensitive Potassium Channels In Learning And Memory, Shaul Vladimir Yahil

Arts & Sciences Electronic Theses and Dissertations

ATP-sensitive potassium (KATP) channels link cellular metabolism and membrane excitability in many tissues, including brain and pancreas. Gain-of-function (GOF) mutations to KATP channels cause neonatal diabetes, with some patients exhibiting developmental delay, epilepsy, and neonatal diabetes (DEND) syndrome. Diabetic symptoms have been attributed to loss of membrane excitability and insulin secretion in pancreatic β-cells, though the origin of neurological deficits and the effects of neuronal KATP-GOF mutations more generally remain elusive. In this dissertation, I will present evidence that mice expressing KATP-GOF mutations pan-neuronally (nKATP-GOF) demonstrated sensorimotor and cognitive deficits, whereas hippocampus-specific hKATP-GOF mice exhibited predominantly learning and memory deficits. …

On Arousal And The Internal Regulation Of Brain Function: Theory And Evidence Across Modalities And Species, Ryan Raut

Arts & Sciences Electronic Theses and Dissertations

The brain is an organ. It is subject to the same physiological regulatory processes that engage the rest of the body’s organs, sculpted over hundreds of millions of years to sustain life so effectively. The central message of this thesis is that the holistic functioning of the brain, rather than operating at some level above or independent from these systemic regulatory processes, is deeply related to them. In short, as our limited attention spans might suggest: brain function is internally regulated. I propose that this internal regulation is a primary function of intrinsic brain activity. Chapter 2 provides a theoretical …

Identification Of Multi-Tissue Protein Quantitative Trait Loci And Causal Inference Of Protein Effects In Neurological And Other Complex Human Diseases Via Mendelian Randomization, Chengran Yang

Arts & Sciences Electronic Theses and Dissertations

Alzheimer disease (AD) is the most common neurodegenerative disease, affecting 6.2 million people mostly aged 65 years or older in the United States as of early 2021. AD has been widely studied and characterized worldwide, but there is still no effective treatment or cure. Even the latest FDA-approved treatment, Aducanumab, cannot stop decline or improve cognition. To develop a truly effective treatments, researchers keep discovering genetic and molecular mechanisms underlying the disease. Protein biomarkers are keys to bridge the mechanisms to disease. Here, I first used a high-throughput proteomic dataset from three tissues (CSF, plasma, and brain) with array-based genotype …

Defining The Epigenetic And Transcriptional Regulatory Mechanisms By Which Hrsv Ns1 Alters Host Transcriptional Response, Nina Rose Beri

Arts & Sciences Electronic Theses and Dissertations

No abstract provided.

Influence Of Aging And Cerebrovascular Disease On Neuroimaging Measures Of Alzheimer Disease, Lauren Nicole Koenig

Arts & Sciences Electronic Theses and Dissertations

The overall goal of this dissertation is to gain a better understanding of how Alzheimer disease relates to normal aging and cerebrovascular disease to impact neuroimaging measures in a clinically meaningful way. Both aging and cerebrovascular disease are known to influence measures of Alzheimer disease, making it difficult to separate what changes are attributable specifically to Alzheimer disease. We hypothesize that a better understanding of these relationships will allow future studies to appropriately take these factors into account. In Chapters 2 and 3 we attempt to separate out the influences of normal aging and Alzheimer disease on measures of atrophy. …

Slo2.1 Channels: A New Molecular Mechanism To Regulate Uterine Excitability, Juan Jose Ferreira

Arts & Sciences Electronic Theses and Dissertations

At the end of pregnancy, the uterus transitions from a non-contractile state to a highly contractile state. Two processes primarily drive this transition. First, from the 28th week of pregnancy until labor, the resting membrane potential of uterine (myometrial) smooth muscle cells (MSMCs) gradually becomes more positive (depolarizes) (Parkington et al. 1999). Second, at the end of pregnancy, MSMCs express more oxytocin receptors and become more sensitive to oxytocin (Kimura et al. 1996). However, the detailed mechanisms by which these processes occur have not been determined. My central hypothesis was that the Na+-activated K+ channel SLO2.1 plays a key role …

Causal Function And Bias Correlation Of The Orbitofrontal Cortex In Economic Choices, Shi Weikang

Arts & Sciences Electronic Theses and Dissertations

Economic choices entail two mental processes, value calculation and value comparison (Niehans, 1990). Studies in the last twenty years have shown that neurons in the orbitofrontal cortex (OFC) could support both processes. Namely, in the studies in which monkeys chose between two juice options with various amounts, three functional cell groups had been found in the OFC: offer value cells encode the value of individual juices, chosen juice cells encode the choice in a binary way and chosen value cells encode the value of the chosen juice (Padoa-Schioppa and Assad, 2006). These results suggest a decision circuit within OFC with …

Genetic Risk Factors For Neurodevelopmental Disorders: Insights From Hipsc-Cerebral Organoids, Michelle L. Wegscheid

Arts & Sciences Electronic Theses and Dissertations

Neurofibromatosis type 1 (NF1) is a common neurodevelopmental disorder (NDD) characterized by remarkable phenotypic variability, where affected children manifest a spectrum of central nervous system (CNS) abnormalities, including brain tumors, impairments in attention, behavior, learning disabilities, and an increased incidence of autism spectrum disorder (ASD). A significant barrier to the implementation of precision medicine strategies for children with NF1 is a lack of prognostic risk factors to guide clinical management. However, emerging population-based genotype-phenotype association studies have suggested that the germline NF1 gene mutation may represent one clinically actionable risk factor for NF1-associated neurodevelopmental abnormalities. As a critical step in …

Influence Of Focal Activity On Macroscale Brain Dynamics In Health And Disease, Zachary Pollack Rosenthal

Arts & Sciences Electronic Theses and Dissertations

Macroscopic recordings of brain activity (e.g. fMRI, EEG) are a sensitive biomarker of the neural networks supporting neurocognitive function. However, it remains largely unclear what mechanisms mediate changes in macroscale networks after focal brain injuries like stroke, seizure, and TBI. Recently, optical neuroimaging in animal models has emerged as a powerful tool to begin addressing these questions. Using widefield imaging of cortical calcium dynamics in mice, this dissertation investigates the mechanisms by which focal disruptions in activity alter brain-wide functional dynamics. In two chapters, I demonstrate 1) that focal sensory stimulation elicits state-dependent, global slow waves propagating from primary somatosensory …

Macronutrient Intake: A Multi-Sport Study Of Female Division I Collegiate Athletes, Ffion Price

Theses and Dissertations

Background: Macronutrients play a critical role within collegiate athletes’ performance and health, with carbohydrates providing most of the energy needs for most athletes. There is little research examining the macronutrient intake of healthy collegiate female athletes across sports. The aim of the present study was to compare macronutrient intakes of female collegiate athletes within different sports and compare their intakes to recommendations. Methods: An observational study was conducted to determine whether a sample of female collegiate athletes (n=26) consumed the IOC nutritional recommendations. Sports included within the study were soccer, basketball, volleyball, and cross-country. Athletes were asked to complete a …

Investigating A Novel Receptor That Mediates Vasoconstriction In Mouse Femoral Arteries, Joselia Carlos

Electronic Thesis and Dissertation Repository

The synthetic peptide trans-cinnamoyl-leucine-isoleucine-glycine-arginine-leucine-ornithine-amide (tcLIGRLO) causes smooth muscle contraction in mouse femoral arteries. The identity of the receptor that mediates this response is undetermined. We hypothesize that the novel mechanism for tcLIGRLO-induced contractions involves a G-protein coupled receptor (GPCR) and a G_q-Ca²⁺ signalling pathway. Chapter 2 describes experiments using femoral arteries isolated from male and female systemic protease-activated receptor 2 (PAR2KO) mice (n=31; 21 – 39 weeks of age) using tcLIGRLO and the G_q-inhibitor, YM-254890 (YM). Contractions produced by tcLIGRLO did not differ by sex but decreased as age increased. YM inhibited tcLIGRLO-induced contractions. Chapter …

Developing Core-Shell Silver/Polymeric Nano-Composites As Drug Nano-Carriers For Breast Cancer Therapy, Nancy Mohamed El-Baz

Archived Theses and Dissertations

In an attempt to find an effective cancer therapy, nanotherapeutics comes onto the scene as a new therapeutic approach, which is emerging both nanotechnology and biotechnology. Nanotherapeutics offer tremendous advantages over conventional cancer therapy including prolonged drug systemic circulation half-life, targeted drug delivery and nanoparticles-based combination therapy, which result in improving drug pharmacokinetic profile and efficacy/toxicity balance. Recently, ongoing studies regarding cancer therapy are focusing on the anticancer action of various inorganic nanoparticles such as gold (AuNPs) and silver (AgNPs) nanoparticles. In fact, AgNPs have proven a potent anticancer action on different cancer types.

Applications Of Genetic Testing For Endocrine And Metabolic Disorders, Amanda Berberich

Electronic Thesis and Dissertation Repository

Knowledge of inherited diseases and the ability to rapidly, efficiently and comprehensively perform genetic testing are advancing steadily. However, the ideal approach to translate this ability into clinical applications for endocrine disorders has yet to be determined. This work focuses on aspects of clinically translating knowledge of select heritable endocrine and metabolic conditions.

For maturity onset diabetes of the young (MODY), a monogenic disorder with no current consensus guidelines governing testing procedures, this work addresses methods to improve detection by validating the use of next generation sequencing-based techniques to identify MODY cases and to detect copy number variations.

For very …

Endothelial Dysfunction In Hindlimb Arteries Of Old Sprague Dawley Rats, And The Type 2 Diabetic Zucker Diabetic Sprague Dawley Strain., Andrea N. Wang

Electronic Thesis and Dissertation Repository

Ageing, and type 2 diabetes are associated with cardiovascular diseases and endothelial dysfunction. Endothelial dysfunction is characterized by a decline in endothelium-mediated vasodilation. In this thesis, we determined the vascular function of hindlimb arteries supplying skeletal muscle and extremities using isolated arteries and wire myography. For ageing studies, we used Sprague Dawley rats and for type 2 diabetes we used the Zucker Diabetic Sprague Dawley strain. Vasodilation of hindlimb arteries with acetylcholine were impaired in both models. However, protease-activated receptor 2 mediated vasodilation was upregulated in arteries. Evidence of non-nitric oxide mechanisms were also found in peripheral vasculature. These data …

Atrx Inactivation And Idh1-R132h Drive Preferential Sensitivity To Proton Vs. X-Ray Radiotherapy In Glioma Stem Cells, Ángel Adrián Garcés

Dissertations & Theses (Open Access)

Background: Glioma Stem Cells (GSCs) are self-renewable, treatment resistant cells in the glioma tumor mass known to promote tumor development. In contrast to traditional photon-based radiation therapy (XRT), proton radiation therapy (PRT) may induce more complex DNA damage and therefore might have the potential to eliminate GSCs. Although previous studies have individually linked IDH mutations, specifically IDH1^R132H, and ATRX inactivating mutations to improved patient outcomes and suppressed DNA damage repair compared to their respective wild-types, the mechanisms by which these two genetic alterations interact in GSCs treated with PRT compared to XRT are currently unknown. We hypothesize that …

(R)-2,5-Dimethoxy-4-Iodoamphetamine [(R)-Doi] Influences Coping Strategies To An Escapable Social Stress, Kevin Thomas Krupp

Dissertations and Theses

Depressive mood disorders are a leading cause of disability worldwide and pharmacological treatments for these disorders are inadequate, requiring new compounds with greater efficacy be investigated. The etiology of depression is heterogeneous; however, it is well established that stress exposure, and the proinflammatory effects of stress have a major role. Psychedelic compounds have rapid and long-lasting anxiolytic and antidepressive effects in humans and animal models of stress induced affective behavior. However, it is not completely understood how these compounds produce such rapid effects. We investigated whether the psychedelic compound (R)-2,5-dimethoxy-4-iodoamphetamine [(R)-DOI], a selective 5-HT2A partial agonist with potent anti-inflammatory properties, …

Characterizing And Overcoming Resistance To Aminomethylspectinomycins In Gram-Negative Bacteria, Nisha Das

Theses and Dissertations (ETD)

Spectinomycin (SPC) is a broad-spectrum aminocyclitol antibiotic. Its use in agriculture has led to widespread resistance in enteric bacteria, necessitating the development of more effective analogs. Aminomethyl spectinomycins (amSPC) are modified spectinomycins with increased potency against many bacterial species. These species include Legionella pneumophila, which harbors a chromosomally encoded aminoglycoside modifying enzyme (AME). In this study, we follow up on this observation and examine the extent to which the amSPCs are substrates for AMEs through adenylation (ANTs) and phosphorylation (APH). APH(9)-Ia and ANT(3")(9) were expressed in E. coli BL21(DE3) and purified using the Ni-affinity chromatography. The ability of AMEs to …

The Effect Of Cancer Cachexia Progression On The Feeding Regulation Of Skeletal Muscle Protein Turnover, Brittany R. Franch

Theses and Dissertations (ETD)

Cancer cachexia is defined as the unintentional loss of skeletal muscle mass with or without fat loss that cannot be reversed by conventional nutritional support. Cachexia occurs in ~20% of cancer patients. More specifically, 50% of lung cancer patients, the most common cancer worldwide, develop cachexia. Cachexia occurs most often in lung and gastrointestinal cancers, whereas breast and prostate have the lowest rate of cachexia. Cancer-induced cachexia disrupts skeletal muscle protein turnover (decreasing protein synthesis and increasing protein degradation). Skeletal muscle’s capacity for protein synthesis is highly sensitive to local and systemic stimuli that are controlled by mTORC1 and AMPK …

Comparative Metabolism Of Aflatoxin B1 In Two Quail Genera Coturnix Japonica And Callipepla Californica, Sean Moody

All Graduate Plan B and other Reports, Spring 1920 to Spring 2023

Avian species are highly susceptible to the hepatotoxic mycotoxin aflatoxin B₁ (AFB₁). Domesticated turkeys are exquisitely sensitive, due to a combination of highly-efficient hepatic cytochrome P450 (CYP)-mediated bioactivation, and to dysfunctional alpha-class glutathione S-transferases (GSTAs) which typically detoxify the bioactivated electrophilic metabolite exo-AFB₁-8,9-epoxide (AFBO). Wild turkeys are relatively resistant to AFB₁ in large part due to expression of functional GSTAs. Quail, a related Galliforme, are slightly less sensitive in vivo to AFB₁, but whether this is related to the hepatic metabolic profiles of these two critical enzymes has not been rigorously evaluated. …

Test Transferability Of 3d-Mot Training On Soccer Specific Parameters, Micaela Dusseault

Honors Theses

Objective: The benefits of perceptual-cognitive training in elite level athletes has recently been investigated in multiple sports such as basketball, soccer, and archery, but conclusive evidence proving test transferability of 3D-MOT training is lacking. The purpose of this research is to examine the transferability of perceptual-cognitive training to on-field soccer performance parameters. Participants: NCAA Division I women’s soccer players (n=22) between the ages of 18-25 who were placed into either the experimental group (n=10) or control group (n=12). After baseline testing for both groups to determine visual tracking speed (VTS), the experimental group completed 10 3D-MOT training sessions with NeuroTracker …

Role Of Meibum And Tear Phospholipids In The Evaporative Water Loss Associated With Dry Eye., Samiyyah M. Sledge

Electronic Theses and Dissertations

It is generally believed that the tear film lipid surface film inhibits the rate of evaporation (Revap) of the underlying tear aqueous. It is also generally believed that changes in the composition of the tear film lipid layer is responsible for an increase in Revap in patients with dry eye. Both of these ideas have never been proven. The purpose of the current studies was to test these ideas. Revap was measured in vitro gravimetrically. Lipid spreading was measured using Raman spectroscopy and microscopy. The influence of the following surface films on the Revap of the sub phase of physiologically …

Novel Peptide Biomaterials For Enhanced Delivery Of Sirna Cargo For Treatment Of Ovarian Cancer, Timothy Samec

All Dissertations

Ovarian cancer is the 7^th leading cause of cancer related death and the 5^th most commonly diagnosed cancer among women. Primarily diagnosed in stage III or stage IV, aggressive treatment is necessary and involves surgical debulking and administration of systemic chemotherapeutics. Unfortunately, these strategies fall short in effectively treating ovarian cancer and many patients experience local disease recurrence, development of multidrug resistant tumors, regional or distant metastatic events, or a combination of the three. As such, there is a significant need for additional treatment options and methods of delivery to improve therapeutic efficacy and disease survivability.

RNA interference …

Preclinical Development Of Epicertin, A Novel Biotherapeutic For The Treatment Of Ulcerative Colitis., Micaela Ann Reeves

Electronic Theses and Dissertations

Epicertin (EPT) is a recombinant variant of the cholera toxin B subunit with a C-terminal KDEL endoplasmic retention motif. Previously, orally administered EPT demonstrated mucosal healing activity in acute and chronic dextran sulfate sodium colitis models, indicating its therapeutic potential for ulcerative colitis (UC) treatment. However, oral dosing with EPT requires neutralization of gastric acid prior to administration, hindering its facile application in the treatment of chronic diseases like UC. One solution to this issue is that EPT may also be administered intracolonically without losing efficacy. This work describes the determination of a target intracolonic dose of EPT for future …

Differentiating The Mechanistic Role And Chemotherapeutic Potential Of Src And Podoplanin In Oncogenic Transformation, Edward P. Retzbach

Graduate School of Biomedical Sciences Theses and Dissertations

There were an estimated 20 million new cancer cases worldwide in 2020, resulting in nearly 1000 deaths per hour [1]. Oral cancer exemplifies the difficulties of treating cancer patients. The first line for oral cancer treatment is surgery and radiation that can lead to patient disfigurement and decreased quality of life in cancer survivors [2-4]. Though there have been many developments in chemotherapy in the last 30 years, the 50% mortality rate associated with oral cancer has not changed [4, 5]. Longitudinal studies that track survival rates in oral cancer patients demonstrate a 3-fold reduction in patient deaths when patients …

The Physiological Benefits Of A Plant-Based Diet On Cardiovascular Health, Jenevieve Petray

Nursing | Senior Theses

Cardiovascular disease (CVD) is increasingly more prevalent in today’s society and is attributed to an alarming percentage of American hospitalizations and deaths. Americans are unhealthier than ever before, and the main contributor is the Western diet. Diet is a double-edged sword that can offer benefits or detriments to one’s health. CVD encompasses numerous diagnoses originating from various underlying physiological alterations. These alterations are downstream effects of increased body weight and BMI, increased cholesterol levels, decreased insulin sensitivity and increased arterial plaque buildup. Research shows that a plant-based diet has the potential to manage and reverse all fundamental physiological alterations that …