Medicine and Health Sciences Commons^™

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 …

Urinary Bile Acid Indices As Prognostic Biomarkers For The Complications Of Liver Diseases, Wenkuan Li

Theses & Dissertations

Hepatobilary diseases cause the accumulation of toxic bile acids (BA) in the liver, blood, and other tissues, which may lead to an unfavorable prognosis. In this study, we compared the urinary BA profile in 257 patients with hepatobilary diseases during a 7-year follow-up period. We investigated the use of the urinary BA profile to develop logistic regression models to predict the prognosis of hepatobiliary diseases in terms of developing disease-related complications, especially for ascites. The urinary BA profile was characterized by calculating BA indices, which quantify the composition, metabolism, hydrophilicity, and toxicity of the BA profile. All patients had high …

Use Of Telehealth In Home-Based End-Of-Life Care For Children In Rural Regions, Meaghann S. Weaver

Theses & Dissertations

A national shortage in pediatric-trained providers results in certain geographies, primarily rural, where children with special needs are not able to access home-based care at their end-of-life. Advances in technology have made the use of telemedicine a potential modality for palliative care subspecialty clinicians to provide clinical care and support for adult-trained hospice teams. This dissertation utilizes four approaches to consider telehealth as an unexplored opportunity in care delivery: (1) a systematic review of telehealth measures and instruments to select the Technology Acceptance Model as a validated metric of telehealth acceptance uniquely now applied to pediatric care; (b) a pilot …

Proof Of Concept: The Use Of Renal Biomarkers In Critically Ill Pediatric Patients For Therapeutic Drug Monitoring, Christopher Lee Shaffer

Theses & Dissertations

Acute kidney injury (AKI) is a serious and common complication in critically ill pediatric patients. The incidence of pediatric AKI continues to increase, especially in patients who undergo surgical correction of congenital heart defects. Serum creatinine and urine output are the most commonly used tools to assess renal function, with international guidelines standardizing AKI-definitions based upon these parameters. However, changes in serum creatinine can occur 24 hours or later after a renal insult event, delaying the diagnosis and potential interventions to reverse injury. It is critical to identify endogenous renal biomarkers within the pediatric population that are both timely and …

Molecular Pathogenesis Of A Novel Subgroup Of Peripheral T-Cell Lymphomas, Jiayu Yu

Theses & Dissertations

Peripheral T-cell Lymphoma (PTCL) consists of numerous distinct disease entities. With the current diagnostic criteria over a third of the cases cannot be further classified and are called "not otherwise specified" (PTCL-NOS). Using gene expression profiling (GEP) of tumors, we identified two novels PTCL-NOS molecular subgroups either characterized by high expression of GATA3 (33%), which is associated with Th2 cell differentiation, or high expression of TBX21 (49%) which regulates Th1 cell maturation. Therefore, stratifying patients for diagnosis and identifying the underlying genetic basis to improve clinical therapy becomes critical to prognosis.

First, we performed DNA copy number analysis by using …

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 …

The Utility Of An Initial Point-Of-Care Lactate In Predicting In-Hospital Mortality Among Adult Patients With Sepsis And Septic Shock At The Emergency Department Of A Tertiary Hospital In Nairobi, Gicheru B. Nyachira

Theses & Dissertations

Background: Sepsis is a leading cause of death and now a global health priority. Rapid identification, diagnosis and intervention can result in reduced in-hospital mortality. Elevated lactate has been shown to be a strong predictor of in-hospital mortality. However, the optimal cut-off has not been well defined. Identification of the optimal Point-of-Care (POC) lactate cut off that best predicts in-hospital mortality can therefore be used to rapidly risk stratify patients with suspected sepsis and septic shock presenting to the emergency department allowing for immediate intervention.

Objective: To determine the lactate cutoff from an initial Point-of-Care lactate result from a GEM …

Neural Oscillatory Activity Serving Sensorimotor Control Is Regulated By The Mitochondrial Redox Environment In Health And Disease, Rachel Spooner

Theses & Dissertations

Despite effective regimens of combination antiretroviral therapy, individuals with HIV are still at higher risk for developing forms of cognitive impairment, with one of the most common behavioral abnormalities to manifest being motor dysfunction. This is an important consideration, as deficits in motor control likely contribute to higher-order cognitive impairments, which together, lead to functional dependencies in the ever-growing aging population of HIV-infected adults. While the neuroanatomical bases of motor dysfunction have recently been illuminated in people living with HIV (PLWH), there remains an open question regarding the molecular processes supporting the circuit-level neuronal dynamics that potentially serve these behavioral …

The Effect Of Polyunsaturated And Saturated Fatty Acids On Seizure Presence And Severity In A Cohort Of Subjects In An Epilepsy Monitoring Unit, Jana K. Wells

Theses & Dissertations

Ketogenic diet therapies (KDTs) have been used to treat epilepsy for nearly 100 years. Although effective, restrictive diet patterns and unknown impacts on long-term health outcomes often prevent their use as first-line therapy. To date, a distinct mechanism of action for KDTs has not been determined and evidence suggests fatty acids (FAs) may play a role in eliciting anti-seizure effects. This dissertation aimed to provide insights into the effect of polyunsaturated fatty acids (PUFAs) and saturated fatty acids (SFAs) on seizure presence and severity through the analysis of dietary intake in a cohort of patients admitted to an epilepsy monitoring …

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 …

The Role Of Vgll4 And Mark2-Hdac Axis In Mitosis And Cancer, Yongji Zeng

Theses & Dissertations

The Hippo pathway is an evolutionarily conserved signaling pathway that plays important roles in stem cell biology, tissue homeostasis, and cancer development. The Hippo core signaling pathway features a kinase cascade consisting of mammalian sterile-20 like protein 1/2 (Mst1/2) and large tumor suppressor 1/2 (Lats1/2). Inactivation of the Hippo pathway is correlated with the promotion of proliferation and anti-apoptosis through activation of the transcriptional co-activator Yes-associated protein (YAP). YAP functions through binding with TEA-domain transcription factors (TEAD1–4) to activate target genes.

Vestigial-like 4 (Vgll4) functions as a transcriptional co-repressor in the Hippo-Yes associated protein (YAP) pathway. Vgll4 inhibits cell proliferation …

Clinical Consequences And Determinants Of False Positive Blood Cultures In Adult Hospitalized Patients, Sidra Liaquat

Theses & Dissertations

Blood cultures are the gold standard for detecting blood stream infections. However, in the US, 0.6-6% of all blood cultures get contaminated leading to adverse clinical outcomes such as unnecessarily prolonged hospital stay and antibiotic therapy. Using electronic medical records, we explored the clinical outcomes and patient-specific risk factors of contaminated blood cultures in an era where rapid blood culture testing was being utilized to provide blood culture results within hours. Rapid blood culture test results can help clinicians in early and more effective management of patients with contaminated blood cultures, thus improving clinical outcomes. We also studied the impact …

An Explanatory Sequential Mixed Methods Nutrition And Physical Activity Intervention Study On Changes In Knowledge, Self-Efficacy, And Outcome Expectations Of Fathers, Sarah Hortman

Theses & Dissertations

Overweight and obesity rates are a continuing concern resulting in poor health outcomes and annual healthcare costs in the billions of dollars. An upstream approach of health promotion is critical to change the focus from treatment and management to prevention of chronic disease. Preventing chronic disease through evidence-based health promotion practices incorporating educational interventions aimed at dietary and physical activity behaviors will preclude negative health outcomes including cardiovascular disease, type 2 diabetes, and hypertension.

The family environment is an important consideration in the prevention of chronic disease including obesity. Parents are role models for their children, including fathers who are …

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 …