Digital Commons Network^™

Survival Analysis Of Colorectal Cancer Patients With Liver Metastasis, Brandon O’Grady

Dissertations & Theses (Open Access)

Background- Colorectal cancer is the third most common cancer in the world. I investigated the survival rates among colorectal cancer patients diagnosed with hepatic metastasis to see if any variables are associated colorectal risk and survival. Methods- Patients were diagnosed from 2000-2019 and collected through MD Anderson’s database. A descriptive analysis, univariate analysis, Kaplan-Meier with Mantel log-rank test, Cox proportion hazard regression and a Stratified Cox Model was performed to investigate death. A competing risk regression was implemented to investigate liver recurrence. Results- There was a clear difference in the survival outcome between liver surgery patients and non-liver surgery patients …

Breastfeeding Duration And Reasons Given For Early Cessation Of Breastfeeding Among Wic Mothers, Amy Willa

Dissertations & Theses (Open Access)

The Breastfeeding Duration and Reasons for Early Cessation of Breastfeeding Among WIC Mothers study was conducted to describe the duration of and factors associated with early breastfeeding cessation among the Women, Infants, and Children (WIC) population. We collected data from a random sample of WIC medical records, sampling medical records belonging to mothers who initiated breastfeeding an infant but did not breastfeed to 52 weeks. Data were analyzed to answer the questions: How long do WIC mothers breastfeed? What reasons are given during counseling sessions at WIC for early cessation of breastfeeding? Do socio-economic, demographic, or medical factors influence the …

P53 Drives A Transcriptional Program That Elicits A Non-Cell-Autonomous Response And Alters Cell State In Vivo, Sydney Moyer

Dissertations & Theses (Open Access)

Cell stress and DNA damage activate the tumor suppressor p53, triggering transcriptional activation of a myriad of target genes. The molecular, morphological, and physiological consequences of this activation remain poorly understood in vivo. We activated a p53 transcriptional program in mice by deletion of Mdm2, a gene which encodes the major p53 inhibitor. By overlaying tissue-specific RNA-sequencing data from pancreas, small intestine, ovary, kidney, and heart with existing p53 ChIP-sequencing, we identified a large repertoire of tissue-specific p53 genes and a common p53 transcriptional signature of seven genes which included Mdm2 but not p21. Global p53 activation …

The Role Of Daam1 In Kidney Development, Vanja Krneta-Stankic

Dissertations & Theses (Open Access)

Kidneys, like most organs in our bodies, consist of a network of epithelial tubules. Kidney tubules are called nephrons, and their morphology is important for kidney function. Nephrons develop from mesodermally derived aggregates of progenitor cells. The nephric progenitors organize into nephric tubules lined with hair-like sensory projections called cilia. Many diseases of the kidney are characterized by abnormal nephron morphology with current treatment aimed at symptom control. To understand the mechanisms underlying kidney diseases and achieve the development of novel therapies, a better understanding of how nephrons develop is needed. Although the actin cytoskeleton is critical for cell behaviors …

Qki-Mediated Cholesterol Biosynthesis In Eye Lens And Myelin Of The Central Nervous System, Seula Shin, Seula Shin

Dissertations & Theses (Open Access)

Cells obtain cholesterol in two ways, de novo biosynthesis and uptake from circulation. While most tissues utilize both sources, eye lens and brain depend extensively on cholesterol biosynthesis due to the limited supply from circulation. Lens cell membrane consists of highest portion of cholesterol. Brain is the most cholesterol-rich organ, which accounts for 23% of total cholesterol. Genetic mutations of cholesterol biosynthesis enzymes in humans and animal models present cataracts and hypomyelinating disorders linked to neurological impairment. Yet, it remains unclear how gene expression of cholesterol biosynthesis is regulated in lens and brain. Therefore, studying cholesterol biosynthesis in both tissues …

Qki-Mediated Cholesterol Biosynthesis In Eye Lens And Myelin Of The Central Nervous System, Seula Shin, Seula Shin

Dissertations & Theses (Open Access)

Cells obtain cholesterol in two ways, de novo biosynthesis and uptake from circulation. While most tissues utilize both sources, eye lens and brain depend extensively on cholesterol biosynthesis due to the limited supply from circulation. Lens cell membrane consists of highest portion of cholesterol. Brain is the most cholesterol-rich organ, which accounts for 23% of total cholesterol. Genetic mutations of cholesterol biosynthesis enzymes in humans and animal models present cataracts and hypomyelinating disorders linked to neurological impairment. Yet, it remains unclear how gene expression of cholesterol biosynthesis is regulated in lens and brain. Therefore, studying cholesterol biosynthesis in both tissues …

Packaging And Secretion Of Airway Mucins, Oanh Ngoc Hoang

Dissertations & Theses (Open Access)

In the conducting airways of the lungs, the mobile mucus gel layer sits on top of the airway epithelium, and through ciliary beating it is propelled up the trachea into the pharynx where it is swallowed and cleared. This gel layer is composed of secreted mucins that become hydrated once reaching the airway lumen. Mucins are secreted at a baseline rate and at a stimulated rate, dependent on the amount of agonist. Baseline secretion is responsible for steady clearance of inhaled particles and pathogens. Stimulated secretion is thought to play a role in trapping helminths though mucus occlusion in small …

Combined Inhibition Of Ddr1 And Cdk4/6 Induces Synergistic Effects In Er-Positive, Her2-Negative Breast Cancer With Pik3ca/Akt1 Mutations, Maryam Shariati, Maryam Shariati

Dissertations & Theses (Open Access)

COMBINED INHIBITION OF DDR1 AND CDK4/6 INDUCES SYNERGISTIC EFFECTS IN ER-POSITIVE, HER2-NEGATIVE BREAST CANCER WITH PIK3CA/AKT1 MUTATIONS

Maryam Shariati, M.S. Advisory Professor: Funda Meric-Bernstam, M.D.

Molecular alterations in the phosphatidylinositol 3‑kinase (PI3K)/ serine/threonine protein kinase B (AKT) signaling pathway occur frequently in estrogen receptor–positive (ER-positive) breast tumors. Patients with ER-positive, human epidermal growth factor receptor 2–negative (HER2-negative) metastatic breast cancer are often treated with cyclin-dependent kinase (CDK4/6) inhibitors such as palbociclib in combination with endocrine therapy. Although this is a very effective regimen, disease progression ultimately occurs in most patients. Further, the modulators of palbociclib sensitivity remain unclear. The purpose …

Inducible Epithelial Resistance Against Acute Viral Pneumonia And Chronic Asthma, Shradha Wali

Dissertations & Theses (Open Access)

Viral pneumonia remains a global health threat despite worldwide vaccination and therapeutic programs. The influenza pandemic of 1918 and SARS-CoV2 pandemic of 2019-2020 are cautionary reminders demanding the need for novel treatment strategies. Moreover, in addition to causing acute disease, respiratory virus infections are often complicated by chronic lung pathologies, such as asthma induction, progression, and exacerbation. We have reported that mice treated with a combination of inhaled Toll-like receptor (TLR) 2/6 and TLR 9 agonists (Pam2-ODN) to stimulate innate immunity are broadly protected against respiratory pathogens, but the mechanisms underlying this protection remain incompletely elucidated. Here, we show in …

The Role Of Daam1 In Kidney Development, Vanja Krneta-Stankic

Dissertations & Theses (Open Access)

Kidneys, like most organs in our bodies, consist of a network of epithelial tubules. Kidney tubules are called nephrons, and their morphology is important for kidney function. Nephrons develop from mesodermally derived aggregates of progenitor cells. The nephric progenitors organize into nephric tubules lined with hair-like sensory projections called cilia. Many diseases of the kidney are characterized by abnormal nephron morphology with current treatment aimed at symptom control. To understand the mechanisms underlying kidney diseases and achieve the development of novel therapies, a better understanding of how nephrons develop is needed. Although the actin cytoskeleton is critical for cell behaviors …

Determining The Utility Of Hl7® Fast Healthcare Interoperability Resources (Fhir®) Standards In Supporting Ehr And Edc-Agnostic Esource Implementations For Clinical Research, Maryam Garza

Dissertations & Theses (Open Access)

Advances in efficiency while maintaining or improving quality are immediately needed in clinical research, specifically for multicenter clinical studies. Though recent evidence points toward electronic health record (EHR) to electronic data capture (EDC) system (EHR to EDC) data collection as a viable contribution, there are many unanswered process and outcome-level questions regarding quality, site burden, and cost within the context of multicenter clinical trials. Direct extraction and use of EHR data in multicenter clinical studies is a long-term and multifaceted endeavor that includes design, development, implementation and evaluation of methods and tools for semi-automating tasks in the research data collection …

Epidemiology Of No -Syndromic, Orofacial Clefts In A Registry­Based, Birth-Cohort In Texas: Differences By Cleft Type And Presence Of Additional Defects, Maria Luisa Navarro Sanchez

Dissertations & Theses (Open Access)

Although orofacial clefts, which include cleft palate alone (CP) and cleft lip with or without cleft palate (CL±P), are among the most common birth defects, their etiology is complex and is generally not well understood. While some clefts are caused by rare syndromes, the majority occur in the absence of a syndrome, either in association with co-occurring defects or as isolated defects. Among these non-syndromic cases, epidemiologic studies have identified demographic variables that are associated with CP and/or CL±P, such as geographic location and infant sex, as well as several maternal characteristics, though some of these associations have been weak …

Cross-Sectional Analysis Of The Relationship Between Violent Crime And Mental Health Disorders In A Sample Of Homeless Adults Recently Released From Jail, Addison Ransom

Dissertations & Theses (Open Access)

Adverse mental health conditions among incarcerated populations are high, and treatment for these conditions is particularly low. Additionally, there is a culture of stigma in the United States towards those with mental health conditions and violent criminal history, contributing to mass incarceration. The present cross-sectional study sought to assess the association between violent criminal history and mental health symptoms among recently incarcerated homeless adults in Dallas, Texas. This study included 230 participants, taking place at The Bridge Homeless Recovery Center, evaluating non-violent versus violent criminal history. Outcome measures of positive screens for post-traumatic stress disorder, generalized anxiety disorder, and depression …

Effect Of The Expanded Prospective Payment System On Dialysis Initiation, The Usage Of Erythropoiesis-Stimulating Agents, And Medicare Expenditures, Lu Zhang

Dissertations & Theses (Open Access)

In January 2011, the U.S. Centers for Medicare & Medicaid Services (CMS) implemented the expanded prospective payment system (PPS) for financing the management of end-stage renal disease (ESRD). Expanded PPS may not only change healthcare providers’ decisions about patient care by removing the financial incentives associated with the previous composite rate payment methodology, but also change the Medicare expenditures associated with various treatment patterns by using a constant base rate for all dialysis modalities. This study aimed to examine the effect of the expanded PPS on providers’ decisions on timing of dialysis initiation and ESA utilizations in ESRD patients as …

Hospital Market Analysis Using A Cohort Of Privately Insured Patients With Total Hip And Knee Replacement Procedures, Elifnur Yay Donderici

Dissertations & Theses (Open Access)

Background: Several recent studies have analyzed the contribution of hospital inpatient prices and utilization to variation in medical spending. However, it is still unknown how the drivers of spending for specific procedures differ within privately insured patients. Next, the market concentration of hospitals has been a matter of concern for several decades. However, researchers usually calculate Herfindahl-Hirschman index (HHI) as a measure of market concentration or power, but there is a drawback of using this measure. Hospitals sell differentiated products, and the HHI measure does not take this differentiation into account in its formulation (Gaynor and Town, 2011). Objective: First …

Health Disparities Across Funcitonal Disability Groups, Katherine Sanches

Dissertations & Theses (Open Access)

Background: People with disabilities experience higher rates of chronic disease and poor health status compared to those without disability. People with disabilities do not participate in community health programs to the same degree as those without disability due to social, programmatic, and environmental barriers. The Community Health Inclusion Index (CHII) is a community health assessment tool which evaluates the degree to which community-level health promoting opportunities to promote nutrition and physical activity are inclusive and accessible to people with disabilities. The CHII assess barriers to inclusion across five domains: build environment, equipment, program/services, staff, and policies. Objective: The purpose of …

The Direct Primary Care Model: Practice Characteristics And Patient Experience, James David Miller

Dissertations & Theses (Open Access)

The Direct Primary Care practice model has been growing in both number of practices and public awareness. However, there has been little academic research about this emerging practice model. This research is aimed to describe the current state of the DPC practice model by examining the services provided, geographic distribution of practices, statistical distribution of membership fees, demographic characteristics of physicians using the model and to determine whether regional pricing variation existed. In addition, differences were analyzed between the patient satisfaction levels in DPC and fee-for-service practices. A dataset was created by visiting the website of all known, non-corporate, DPC …

Determining The Racial And Ethnic Differences In Neonatal Intensive Care Unit Admission Rates, Youngran Kim

Dissertations & Theses (Open Access)

Background: Recent trends show that the utilization of neonatal intensive care unit (NICU) has extended beyond severely ill infants and increased substantially across all birth weights. However, little is known about what drives the growth of NICU admission rates and whether these trends differ by race/ethnicity. Methods: The study used 2008-2018 Natality Files with restricted use of state and county-level information. Crude and risk-adjusted NICU admission rates, overall and stratified by birth weight group, were compared between black and white infants and between Hispanic and white infants. Kitagawa decomposition and Oaxaca-Blinder decomposition analyses were conducted for the temporal increase in …

A Comparison Of Interdisciplinary Palliative Care Teams And Leadership Attitudes Of Nci-Designated And Non-Nci-Designated Cancer Centers In The United States From 2009-2018, Joseph Chen

Dissertations & Theses (Open Access)

Background: Interdisciplinary palliative care (PC) teams (IDTs) are essential to improving patient outcomes while cancer center executives have a key role in defining the future of PC. Objectives: To compare PC team compositions and executives’ attitudes towards PC between NCI (National Cancer Institute)-designated cancer centers (NCI-CCs) and non-NCI-designated cancer centers (non-NCI-CCs) in 2018 and to compare changes in team composition and executives’ attitudes and beliefs between 2009-2018. Methods: PC program leaders (PL) and cancer center executives at all 62 NCI-CCs and a random sample of 60 of 1252 non-NCI-CCs were surveyed from April-August 2018. The PL survey examined team composition …

Atitiudes Tow Ards Computer Games For Learning And Pl.A Yer Archetypes: An Exploration Of Measures On Preintervention Player Characteristics For Serious Game-Based Interventions, Benjamin Lee

Dissertations & Theses (Open Access)

Serious game-based interventions offer promising health outcome results with the aid of pre-intervention player tailoring and the development of measurements that evaluate pre-intervention player characteristics and subgroups. Video gaming measures can potentially provide helpful tailoring information that discerns individual video gaming preferences which could influence their overall user experience. It is critical that measures that target adolescent video gaming be psychometrically validated. There is a gap in the literature with psychometrically validated measures evaluating adolescent attitudes towards computer games for learning and gaming archetypes. Therefore the aims of this dissertation were to 1) evaluate the psychometric properties (i.e., reliability and …

The Multilevel Factors Facilitating Or Impeding Healthcare Access Among Refugees Residing In Bexar County Texas, Howaida Werfelli

Dissertations & Theses (Open Access)

The goal of this study was to increase understanding of healthcare access among refugees by investigating the multilevel factors that facilitate or impede healthcare access among refugees who have resettled in Bexar County, Texas. The multilevel factors facilitating or impeding access to healthcare for refugees resettled in Bexar County were identified as follows: health literacy, level of educational attainment, proficiency (reading, writing and, speaking) in English, proficiency (reading, writing and speaking) in native language, translation services, public transportation, income level, a shortage of healthcare providers, navigation of the healthcare system, the fragmentation of the healthcare system, insurance status, staff shortages …

Development And Preliminary Psychometric Testing Of The Drake Atrial Electrogram Assessment Survey: Daegas©, Jeanette Drake

Dissertations & Theses (Open Access)

Background: Critical care nurses (CCNs) who care for postoperative cardiac surgery patients need specialty knowledge, for example, knowledge of atrial electrograms (AEGs). An inadequate audit trail exists for psychometric performance of instruments to measure CCN knowledge of AEGs. A 29-item survey previously pilot tested with a convenience sample of CCNs in the Pacific Northwest had a Kuder-Richardson-20 estimate of internal consistency of .75. The survey was revised to 20 items (14 knowledge and 6 AEG interpretation) and named the Drake Atrial Electrogram Assessment Survey (DAEGAS).

Objectives: The study objectives were to assess evidence for content validity (content validity …

Targeting Unique Domains Of Lsd1 Regulates Pediatric Glioma Innate Immunity And Nk Cell Metabolism, Cavan Bailey

Dissertations & Theses (Open Access)

Regulation of chromatin accessibility is a key mechanism of cellular identity, allowing different tissues to develop using the same DNA template. Cancers will often hijack these epigenetic pathways, reactivating developmental genes to drive growth and deactivating tumor suppressor and immune recognition genes. Chromatin-modifying proteins deposit and remove chemical moieties from histone tails to aid in governing gene expression, and these proteins have become a new therapeutic target in cancer. Traditional chemotherapeutics aim to damage DNA, dysregulate cell division, or block hormonal growth signals, but epigenetic therapy can target vulnerabilities specific to cancer cells and broadly change gene expression patterns that …

Molecular Diagnosis Of Intestinal Parasites: Impact On Growth Among Preschool-Age Children In Rural Ecuador, Patricia Bryan

Dissertations & Theses (Open Access)

Background: Gastrointestinal (GI) parasites may have important influences on growth outcomes during early childhood. Previous studies investigating the effects of GI parasites on growth have predominantly used microscopy-based diagnostic methods with low sensitivity. Few accurate epidemiologic data are available on GI parasitic infections among rural Ecuadorian children. To investigate the impact of single and multiple GI parasite infections on growth during early childhood data from a longitudinal birth cohort in Ecuador were analyzed.

Purpose: The aims of this study were to determine the prevalence of GI parasites (soil-transmitted helminths and intestinal protozoa) and to describe associations between GI parasitic infections …

A Qualitative Inquiry Exploring Help-Seeking Behaviors And Resilience Strategies Women With Disabilities Utilize When Experiencing Gender-Based Violence In Rural Communities, Kimberly Ann Aguillard

Dissertations & Theses (Open Access)

Women with disabilities (WWD) are at pronounced risk of experiencing multiple forms of severe and prolonged violence, and they face barriers to accessing help. A multitude of factors associated with disability and rurality may compound the experience of violence, including geographic and social isolation, forcing WWD in rural settings to navigate extremely dangerous situations with limited avenues for accessing help and securing safety. This research explored how women with disabilities experiencing violence while living in rural communities navigate programs and policies, make decisions about seeking and securing help, and build resilience despite experiencing violence. The current study methodology empowers this …

Bayesian Modeling Of Censored Data With Application To Meta-Analysis Of Immunotherapy Trials, Xinyue Qi

Dissertations & Theses (Open Access)

My dissertation builds on a systematic review of 125 clinical trials reporting on treatment-related adverse events (AEs) associated with PD-1/PD-L1 inhibitors published from 2010 to 2018. The motivating dataset contained the following study-level components extracted from each publication: trial name, number of treated patients, selected immunotherapy drug, dosing schedule, cancer type, number of AEs within each category, and the pre-specified criteria for AE reporting. The number of AEs were reported based upon all-grade (Grade 1-5) and Grade 3 or higher (Grade 3-5) severity. My overall objective was to increase our understanding of the toxicity profiles of five most common cancer …

Using Spatial Methods To Better Understand Food Insecurity And Snap Under-Participation In Texas, Ryan Ramphul

Dissertations & Theses (Open Access)

The overall objective of this research is to use spatial methods to better understand food insecurity and SNAP under-participation in Texas. Paper 1 assesses whether a sample of community dwelling Medicare and Medicaid beneficiaries, who screen positive for food insecurity at healthcare locations in Harris County, exhibit a spatial pattern in terms of where they live. In other words, it tests whether or not there are statistically significant neighborhood hot spots or cold spots of food insecurity against a null hypothesis of complete spatial randomness. This approach is novel because it uses address-level data on patients who report being food …

Physician Burnout: Slowing The Burn Through Positive Deviance Strategies, Swapna Reddy

Dissertations & Theses (Open Access)

Introduction: Affecting 42% of physicians in the United States, “physician burnout” is considered a public health crisis with adverse impacts for personal providers, patients and organizations. Though much research has been devoted to the existence and causes of burnout, to date few studies have been conducted to identify factors associated with physician fulfillment. Aims: This dissertation research was intended to increase and improve knowledge of factors effective in contributing to physician professional fulfillment utilizing a Positive Deviance based approach. To that end, two studies were conducted: the first, a narrative review of the literature to identify specific correlates of physician …

Functional Heterogeneity And Metabolic Adaptation Of Fibroblasts In Cancer, Lisa Becker

Dissertations & Theses (Open Access)

The tumor microenvironment is comprised of a multitude of cell types producing a milieu of cytokines, growth factors an extracellular matrix. Together, this intricate network of cells plays highly critical roles in determining a tumor’s potential to progress and metastasize. As the predominant cell types in the tumor microenvironment, cancer-associated fibroblasts (CAFs) are a key component in the regulation of tumor development and progression, but their exact functions in tumorigenesis remain poorly understood. This is partly due to the considerable heterogeneity amongst these cells, which confounds the characterization of their roles within the tumor microenvironment. Nevertheless, recent studies have provided …

A Partial Likelihood Approach To Longitudinal Categorical Data Using A Continuous Time Semi-Markov Chain Model, Kusha A. Mohammadi

Dissertations & Theses (Open Access)

Longitudinal studies have been critical in understanding the characteristics of chronic diseases or interventions. Since many processes have natural multi-categorical responses over time, multi-state stochastic models have been used to estimate the transition rates between stages. Some multi-state models applied in practice assume the Markov property. The Markov property constrains the sojourn distribution to be exponentially distributed. While useful theoretical properties arise by the Markov assumption, we will consider a more flexible framework by allowing arbitrarily distributed waiting times. This describes a semi-Markov process which has already been applied to various fields in Public Health. Similar to Markov model developments, …