Medicine and Health Sciences Commons^™

Exploiting Vulnerabilities In The Ras-Rac Signaling Pathway For The Selective Targeting Of Pancreatic Cancer Cells, Neha Chaudhary

Theses & Dissertations

Deregulation of the KRas (Kirsten rat sarcoma virus) GTPase is one of the early hallmarks of Pancreatic Cancer (PC). The most common genetic alteration found in PC are mutations in the KRas protein that block its ability to hydrolyze GTP to GDP and resulting in higher levels of GTP-bound KRas, its active form. Pancreatic tumors driven by oncogenic mutants of KRas tend to be addicted to the oncogene, to the extent that its repression leads to the induction of cell death. This addiction to the KRAS oncogene makes the KRas protein an ideal target for cancer therapy. However, the globular …

A Literature Review Of The Psychosocial Impacts On Livestock Producers And Veterinary Responders Involved With Depopulation During And After An Animal Health Emergency, Beth Galles

Capstone Experience

A vital aspect of an animal health emergency in the United States is removing and disposing of diseased and healthy animals through depopulation. It is frequently required to prevent the spread of diseases that affect human health or economic stability. Production animals are eventually slaughtered, but this does not negate the human-animal bond felt between these animals and their caretakers. There is increasing recognition that participation in depopulation may be a traumatic event requiring care for the individuals involved, including livestock producers and veterinarians. Despite this, limited resources are available for these individuals when an animal health emergency occurs. This …

A Cell Culture Model To Study Tobacco Associated Oral Cancer Progression And Treatment Resistance, Amanda Busch

Theses & Dissertations

Head and Neck Squamous cell carcinoma is the 6^th most common cancer in the world. Risk factors for HNSCC include alcohol and tobacco consumption, infection with Human Papilloma Virus, and exposure to environmental toxins. Unlike many other cancers, the incidence of HNSCC is growing, yet the treatment options and outcomes have not been significantly improved for decades. An increased understanding of the molecular mechanisms of these cancers is needed for improvement in early diagnosis, enhanced treatment effectiveness, and cancer prevention. 4-nitroquinoline 1-oxide (4NQO) is a well-tested, tobacco mimicking, carcinogen. 4NQO produces similar histological and chemical changes found in human …

Health Effects Of Neonicotinoids On An Agricultural Community, Jocelyn Rodriguez-Paar

Capstone Experience

Mead, Nebraska, a small United States agricultural community consisting of approximately 600 people, was accidentally exposed to high amounts of neonicotinoids when AltEn, an ethanol plant that used neonicotinoid coated corn and soybean seeds for biofuel, was discovered not disposing of the toxic byproduct safely. Coincidentally, there was also a leak in their wastewater system that also contaminated the nearby areas. Although neonicotinoids are not considered highly dangerous with low dose exposures, large dose exposures can cause symptoms similarly to nicotine poisonings, such as difficulty breathing, vomiting, nausea, hypertension, tachycardia, and lethargy (Imamura, T. et al., 2010). Neonicotinoid poisoning can …

A Systematic Literature Review On The Capability Of Sio₂-Np’S Exposure To Exacerbate Parkinson’S (Pd) Pathology And The Risk Factors For Biomedical Applications In Pd, Seth Abdallah

Capstone Experience

Silica Dioxide nanoparticles (SiO₂-NP) have become increasingly ubiquitous in industry, which has stimulated research into the potential toxicity of these compounds. Recent studies have explored the association between amorphous silica nanoparticle exposure and the potential for neurotoxicity. Additionally, research has been conducted in the application of SiO₂-NP’s in theranostics and as drug directing agents , which based on current literature may be contraindicated for individuals with conditions such as Parkinson's Disease (PD) which is characterized by neuroinflammation. The following literature review will discuss evidence for silica dioxide nanoparticle exposure to induce neurotoxicity which may exacerbate neurodegenerative diseases such as PD. …

Evaluating How Physical Activity Affects The Perception Of Resilience In Box Butte County, Nebraska, Eric Pulver

Capstone Experience

Physical activity is one of the modern hallmarks for good health in individuals and the public, in general. Resiliency is a growing concentration in all levels of disaster preparedness where the focus is on how to deal with the growing number of disasters stemming from global climate change. This research project’s aim is to look at the possible relationships between physical activity and resiliency in a rural Nebraska population. This was done with the use of a cross-sectional study utilizing a fifteen-question survey to gather demographics, assess the amount of physical activity, and then apply a perception of resilience tool …

Characterization Of 1,1-Diarylethylene Foxm1 Inhibitors Against High-Grade Serous Ovarian Carcinoma Cells, Cassie Liu

Theses & Dissertations

Forkhead box M1 (FOXM1) is a member of the conserved forkhead box (FOX) transcription factor family. Over the last two decades, FOXM1 has emerged as a multifunctional oncoprotein and a robust biomarker of poor prognosis in many human malignancies. FOXM1 and its associated oncogenic transcriptional signature are enriched in >85% of ovarian cancer cases, and FOXM1 expression and activity can be enhanced by a plethora of genomic, transcriptional, post-transcriptional, and post-translational mechanisms. As a master transcriptional regulator, FOXM1 promotes critical oncogenic phenotypes in ovarian cancer, including: (1) cell proliferation, (2) invasion and metastasis, (3) chemotherapy resistance, (4) cancer stem cell …

Linking Spinal Cord Circuits With Upper Limb Sensorimotor Control In Adults With Cerebral Palsy, Saihari Dukkipati

Theses & Dissertations

Cerebral palsy (CP) is the most common neurological disorder originating in childhood, but most of the people living with CP are currently adults. While people with CP continue to get older, the amount of research focused on adults has been rather limited. The early childhood insults leading to CP are thought to originate in the brain, but the effects on the entire neuromuscular system across the lifespan have only recently started to be explored. Of note, recent neuroimaging evidence suggests that the cervical spinal cord structure is atypical in adults with CP. However, it is largely unclear how the neurophysiological …

The Role Of Calprotectin In T-Lymphocyte Driven Inflammation In A Mouse Model Of Psychological Trauma, Cassandra Moshfegh

Theses & Dissertations

Post-traumatic stress disorder (PTSD) is a debilitating psychological disorder that affects nearly 45 million Americans. This mental disorder is characterized by behavioral symptoms such as learned helplessness, hyperarousal, withdrawal, and flashbacks. The deleterious effects of PTSD are far-reaching and go beyond behavioral dysfunction, as these individuals are at a three-fold higher risk of comorbid inflammatory diseases. Autonomic, metabolic, and cardiovascular diseases plague these individuals later in their lifetime, however, the mechanistic link connecting psychological trauma to this systemic peripheral immunological dysfunction remains elusive. T-lymphocyte-induced inflammation plays a significant role in all these disease pathologies. Previous work from our laboratory demonstrated …

Gut Commensals Modulate Siv/Shiv Pathogenesis And Therapeutics, Samuel Johnson

Theses & Dissertations

Despite significant advancements in combination antiretroviral therapy (cART), ongoing inflammation in the brain and gut remain two of the most significant hurdles in the health of people living with human immunodeficiency virus (HIV). Additionally, a viral reservoir in each compartment inhibits cure efforts by allowing rapid viral rebound following cART interruption. Emerging understanding of the gut-brain axis (GBA) implicates each compartment in the modulation of the other in a complex bi-directional interaction mediated by vagus innervation, circulating lymphocytes, and microbiome composition and biproducts. Using multiple models of the simian (and simian-human) immunodeficiency virus (SIV/SHIV) and therapeutic intervention, I present how …

Psychological Trauma Alters T-Lymphocyte Inflammation And Redox Through Sympathetic Mechanisms, Safwan K. Elkhatib

Theses & Dissertations

Posttraumatic stress disorder (PTSD) is a devastating psychiatric disorder characterized by distinctive symptom clusters, including intrusive memories (i.e., flashbacks), avoidance of related stimuli, affective changes, and hyperarousal. Strikingly, patients with PTSD face a significantly increased risk for a number of inflammation-driven pathologies, ranging from cardiovascular to autoimmune disease. Yet, the exact etiology of this increased risk remains unknown. The immune system is known to be strongly influenced by the sympathetic nervous system, and sympathetic overactivity is a hallmark of PTSD. Lymphoid organs, such as the spleen, are richly innervated by sympathetic nerve fibers which terminate near adaptive immune …

Polymeric Nanocarriers For Delivery Of Small Molecules Inhibiting Tubulin Polymerization For The Treatment Of Pancreatic Cancer And Lung Metastatic Melanoma, Rajan Sharma Bhattarai

Theses & Dissertations

The aim of this thesis is to develop delivery systems for the novel small molecules which inhibit tubulin polymerization. One of the small molecules was modified to lipid conjugate to increase the lipophilicity of the molecules which in turn drastically improved the drug loading in amphiphilic polymeric system. The second molecule was conjugated to the amphiphilic polymeric backbone with pH sensitive Schiff’s linker for the tumor site specific delivery in lung metastatic melanoma model.

Chapter 1 discusses the tumor microenvironment for the solid tumor especially focusing on Pancreatic Ductal Adenocarcinoma (PDAC). Further the drug delivery system currently researched for addressing …

Frailty And Neurocognition In Prostate Cancer, Lindsey Hanson

Theses & Dissertations

Prostate cancer (PCa) treatment often leads to distressing side effects ranging from muscle loss, physical inactivity, and fatigue to cancer associated cognitive decline (CACD). Evidence suggests that men treated with androgen deprivation therapy (ADT) may have a specifically high risk of CACD, partially due to increased frailty. However, the current literature on cognitive effects of ADT is equivocal. Therefore, the primary objectives of this study were to (1) compare cognitive function, physical activity (PA), and fitness in men receiving ADT, men scheduled to receive radiation, and men under active surveillance for PCa; (2) examine changes in cognitive performance and PA …

Atrazine Levels In Rural Nebraska Counties And Parkinson's Disease, Muhammad Zahid

Capstone Experience

Parkinson's disease (PD) is a multifactorial disorder, connecting both genetic susceptibility and environmental risk factors. Several epidemiological and experimental studies support the evidence that pesticides exposure is positively associated with enhancing neurodegenerative diseases. The high amount of atrazine used in Nebraska and increased PD cases led us to evaluate the association between the long-lived water-soluble pesticide atrazine and PD in Nebraska counties. A person's exposure to atrazine may come from inhalation, dermal absorption, and ingestion. Three types of atrazine data covering 1992 to 2017 were used for this study: applied atrazine, atrazine in surface water, and atrazine in groundwater. In …

Assessing Nutritional Health Knowledge In Sharing Clinic Patients With Diabetes, Minden Huntrods

Capstone Experience

Effective diabetes prevention and management relies on nutritional behaviors, thus a basic level of health knowledge is important for patients with diabetes and their caregivers in their quest to acquire acute glycemic control and minimize negative health outcomes (Ley et al., 2014). The purpose of this study was to assess the nutrition-related health knowledge of patients living with diabetes who are seen at the UNMC Sharing Clinic by use of a verbal questionnaire. This nutritional health knowledge assessment was a quantitative, prospective, survey-based study utilizing descriptive statistics. Approximately 86% of patients were proficient in food group and nutritious foods knowledge …

Development Of A Muc16-Targeted Near-Infrared Antibody Probe For Fluorescence-Guided Surgery Of Pancreatic Cancer, Madeline T. Olson

Theses & Dissertations

Pancreatic cancer (PDAC) is an extremely lethal disease with an overall survival rate of 10%. Surgery remains the only potentially curative treatment option, but resections are complicated by infiltrative disease, proximity of critical vasculature, peritumoral inflammation, and dense stroma. Surgeons are limited to tactile and visual cues to differentiate cancerous tissue from normal tissue. Furthermore, translating preoperative images to the intraoperative setting poses additional challenges for tumor detection, and can result in undetected and unresected lesions. Thus, PDAC has high rates of incomplete resections, and subsequently, disease recurrence. Fluorescence-guided surgery (FGS) has emerged as a method to improve intraoperative detection …

The Rotator Cuff Tendon-To-Bone Interface: Maturation, Aging, And 3d Bioprinting For Regeneration, Xiping Jiang

Theses & Dissertations

Rotator cuff tendon injuries often occur at the tendon-to-bone interface (i.e., enthesis) area with a high prevalence for the elderly population. In addition, regeneration of the gradient structure of the enthesis is still a significant clinical challenge. Our studies aim to identify the histological, molecular, and biomechanical alterations of the rotator cuff enthesis with maturation and aging, and develop a novel therapeutic method using three-dimensional (3D) bioprinting technique to regenerate a functional enthesis. Striking variations of the entheses were observed both histologically and biomechanically during the maturation process. The histological features did not show many differences at the insertion site …

Development Of Macromolecular Prodrug Of Sinomenine For The Treatment Of Rheumatoid Arthritis, Roshni Mukundan

Theses & Dissertations

Inflammation is a natural response of the body to infections or any potential threat to the body. But, sometimes the immune system attacks its own body causing persistent inflammation leading to inflammatory diseases. One of the common chronic inflammatory diseases is rheumatoid arthritis (RA) which causes inflammation of the synovial membrane. The current treatments for RA are effective in controlling the symptoms but they come with severe side effects and economic burden. Further, the management of pain is still a problem with these drugs. Sinomenine is a natural alkaloid obtained from the Chinese medicinal plant Sinomenium acutum that has been …

Dynamics Of Protein-Dna Interactions Characterized By Atomic Force Microscopy, Yaqing Wang

Theses & Dissertations

This thesis describes the nanoscale studies of protein-DNA interactions with different complexities using atomic force microscopy (AFM). One of the systems deals with DNA replication rescue. To maintain the genetic integrity, replication machinery needs to minimize the error rate, repair the damages, and restart the stalled replication caused by the attacks from the environment and inside the cell. The stalled replication rescue is orchestrated by a series of proteins, for example, the DNA helicases PriA and RecG and the ssDNA binding protein (SSB).

We demonstrated that SSB stimulates the restart process in two aspects. First, SSB facilitates the binding of …

Gene Expression Profiling Of Mapk Pathway Inhibitor Resistance In Cutaneous Melanoma: Can Bioinformatics Be Used To Select Better Melanoma Cell Lines?, Stephen Luebker

Theses & Dissertations

Melanoma is the deadliest form of skin cancer, and incidence has continued to increase. Half of all melanomas have a BRAF V600E mutation and respond to MAPK pathway inhibitors, including BRAF inhibitor therapy or BRAF/MEK inhibitor combination therapy, but nearly all patients develop treatment resistance. Melanoma cell lines produce variable results as models of MAPK pathway inhibitor resistance. To better understand how the genomic similarity of a melanoma cell line to patient-derived tumors affects resistance mechanisms, differences in DNA mutations and copy-number alterations were compared between melanoma cell lines profiled by the Cancer Cell Line Encyclopedia and cutaneous melanoma tumors …

Mucin And Splice Variant Profiles Of Pancreatic Adenocarcinoma Predict Patient Survival And Subtyping, Christopher M. Thompson

Theses & Dissertations

PDAC is a pancreatic epithelial malignancy and demonstrates aggressive progression and bleak patient prognosis. Despite decades of research, the evolution of novel diagnostics and intervention modalities for PDAC is stagnant. This dissertation explores the characteristic aberrant and elevated expression of mucins in PDAC. Beginning with the hypothesis that mucins are associated with disease aggressiveness, analysis of PDAC patient survival in TCGA revealed no associations between single mucin expression and patient survival. This led to the underlying issue of PDAC tumor cellularity since this disease demonstrates variability in the proportion of cancer cells within the tumor. Tumor purity assessed with the …

Design, Synthesis And Evaluation Of Novel Inhibitors Of Type 5 And 10 17Β-Hydroxysteroid Dehydrogenases, Ahmed Morsy

Theses & Dissertations

17β-Hydroxysteroid dehydrogenases (17β-HSDs) are essential enzymes in steroid metabolism. More and more evidence points to the pivotal contributions of these enzymes in various other metabolic pathways. Therefore, the latest research results give new insights into the complex metabolic interconnectivity of the 17β-HSDs with human diseases. This dissertation focuses on the metabolic activities of type 5 and 10 17β-HSDs. More specifically, regarding 17β-HSD5 contributions to the progression of prostate cancer (PCa) and 17β-HSD10 aggravation of amyloid-beta (Aβ)-induced toxicity in Alzheimer's disease (AD).

The second leading cause of cancer-related death in males is PCa, with the highest incidence rate of all cancers …

Biomedical Porcine Models For The Study Of Surgical Hemostasis, Hindlimb Ischemia, And Pancreatic Cancer, Shruthishree Aravind

Theses & Dissertations

Murine models have dominated the world of biomedical research and comparative medicine since their development in the early 1900s. [1] While they may be suitable models to study proteomics and genomics, they may not serve as effective translational models. [2-4] Murine models do not accurately model the pathophysiology of human disease and are limited by their size, application of medical imaging and intervention, which reduces their overall preclinical predictive value. [2-4]

Porcine models on the other hand, are slowly and steadily bridging the gap between murine models and human patients. [5] Pigs …

Reach, Effectiveness, Adoption, And Maintenance Of Mobile Electronic Clinical Decision Support Tools Deployed As Part Of National Quality Improvement Projects, Ellen K. Kerns

Theses & Dissertations

Electronic clinical decision support (ECDS) tools are often developed within quality improvement (QI) projects to increase adherence with the latest clinical practice guidelines. However, the potential reach and maintenance of ECDS use beyond the time and location of their associated project are very limited. Deploying ECDS using a mobile app (mECDS) has shown the potential to be a viable method of overcoming these limitations. However, it is unclear what pattern the reach and adoption of such a tool might follow and what effect this use has on clinical practice. Our team developed an app which contained two different mECDS tools …

Neurocognitive Impairment In People Living With Human Immunodeficiency Virus (Hiv): Risk Factors And Mortality, Zaeema Naveed

Theses & Dissertations

Despite the widespread use of combination antiretroviral therapy (cART), HIV-associated neurocognitive impairment (NCI) persists in people living with HIV (PLWH) with clinical and public health implications. Studies have generated inconsistent results regarding etiological factors for NCI in PLWH and a brief user-friendly predictive tool is desirable in clinical practice to assess the probability of having NCI in PLWH. Furthermore, factors associated with clinically meaningful decline in neurocognitive status and survival disadvantage for patients with NCI are understudied in the post-cART era. The goal of this dissertation was to investigate factors associated with baseline NCI and neurocognitive decline and the association …

Multimodal Neuroimaging Of Hiv And Aging, Brandon Lew

Theses & Dissertations

HIV infection remains a significant contributor to disease burden, and with the success of antiretroviral therapies, the population of people with HIV is aging. A growing literature suggests a relationship between HIV-infection and a profile of age advancement, most notably in molecular studies of epigenetics. However, despite the widely-known high prevalence of HIV-related brain atrophy, functional deficits, and HIV-associated neurocognitive disorder (HAND), epigenetic age advancement has not been linked to HIV-related changes in neuroimaging metrics.

We applied three neuroimaging methods, structural MRI, resting state functional MRI, and resting state MEG, to study the brain structure and function of 121 virally-suppressed …

Secreted Mucin 5ac-Mediated Epithelial And Stromal Modulations Augment Pancreatic Cancer Aggressiveness, Koelina Ganguly

Theses & Dissertations

The mucosal layer that shields the epithelium of the body cavities is made up of high molecular weight, heavily glycosylated proteins called mucins that are broadly categorized into transmembrane and secreted members. Aberrant expression of secreted mucin MUC5AC has been implicated in lung, stomach, and colon cancer pathologies. MUC5AC is expressed de novo in the pancreas upon oncogenic insult, and its abundance in pancreatic tumor and circulation correlates to disease progression. However, few studies have explored beyond the diagnostic and prognostic significance of MUC5AC in pancreatic cancer (PC).

In this dissertation, we sought to investigate the mechanistic contribution of MUC5AC …

Quantifying Fear Of Falling By Utilizing Objective Body Sway And Muscle Contraction Measures, Chenfan Gui

Theses & Dissertations

Fear of falling (FOF) is a psychological condition that can lead to increased morbidity and mortality in the elder population. However, the subjective and multidimensional nature of FOF resulted in the limitations of existing FOF measurements, which could influence the quality of those studies. The present study aimed to quantify FOF by using objective center of pressure (COP) trajectories and muscle contraction of the lower extremity to compensate for those limitations. Nineteen young healthy adults (24 years ± 2.47) were recruited in the present study. Subjects were required to watch three 360-degree videos, one control video and two roller coaster …

Development Of Long-Acting Antiviral Drug Nanoformulations, Denise Cobb

Theses & Dissertations

Antiretroviral therapy (ART) has improved the quality and duration of life for people living with human immunodeficiency virus (HIV) infection. However, opportunities to improve its profile abound. ART is limited by putative viral reservoir penetrance, emergence of viral mutations, inherent toxicities, and regimen non-adherence. These highlight the need improved drug delivery schemes. Previously, our lab has demonstrated that targeting mononuclear phagocytes for antiretroviral drug delivery extends drug half-life and improves penetrance into viral reservoirs, addressing these limitations of ART. Herein, we developed synthetic and biologic antiretroviral (ARV) drug nanocarriers improve the pharmacokinetic (PK) and pharmacodynamic (PD) profiles of ARVs through …

The Effect Of Fiber And Omega-6:Omega-3 Fatty Acid Ratio On Asthma And Asthma-Related Symptoms In An Adult U.S. Population, Korie As Nelson

Capstone Experience

Asthma is one of the most common diseases in the world affecting more than 10% of adults in many westernized countries and 339 million globally. Studies have shown a positive association between increased dietary fiber and improvement in asthma-related inflammation. Omega-3 fatty acids have also been shown to help mitigate inflammation in general. No identified studies have looked at the synergistic effect of omega-3 and omega-6 fatty acids alone and as a ratio with fiber on asthma, lung function, and respiratory morbidities. A positive association could mean that dietary interventions of fiber and fatty acids could significantly improve asthma and …