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Heat Stress Related Symptoms And Pulmonary Function In Oil Spill Response And Cleanup Workers Following The Deepwater Horizon Disaster, Yiyou Li

Dissertations and Theses (Open Access)

The objective of this study was to estimate the relationship between heat stress and pulmonary function among OSRC workers following the Deepwater Horizon (DWH) disaster. Methods: Pulmonary function test results were analyzed from a cohort of oil spill response and cleanup workers 1-3 years following the DWH disaster (N=5,131). Proxies for heat stress was employed by using information on heat stress-related symptoms as well as a questionnaire on stopping work due to heat reported during a structured telephone enrollment questionnaire. Associations between heat stress proxies and lung function were estimated using multivariable linear models and binomial logistic regression models while …

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 and 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 …

Heat Stress Related Symptoms And Pulmonary Function In Oil Spill Response And Cleanup Workers Following The Deepwater Horizon Disaster, Yiyao Li

Dissertations and Theses (Open Access)

Objective: The objective of this study was to estimate the relationship between heat stress and pulmonary function among OSRC workers following the Deepwater Horizon (DWH) disaster. Methods: Pulmonary function test results were analyzed from a cohort of oil spill response and cleanup workers 1-3 years following the DWH disaster (N=5,131). Proxies for heat stress was employed by using information on heat stress-related symptoms as well as a questionnaire on stopping work due to heat reported during a structured telephone enrollment questionnaire. Associations between heat stress proxies and lung function were estimated using multivariable linear models and binomial logistic regression models …

Area-Level Landfill Density And Asthma Prevalence In Urban Texas Areas, Jessica Meighan Herrin

Dissertations and Theses (Open Access)

Environmental exposures, especially air pollutants, pose a threat for an increase in asthma prevalence. In particular, hydrogen sulfide (H2S) gas can cause severe health effects closely resembling asthmatic symptoms. Ambient concentrations of H2S gas correlates with the amount of solid waste found in landfills. The potential for adverse health risks associated with H2S emitted from landfills is of concern for those populations living in close proximity to landfills. Asthma is one of the adverse health effects that can occur due to H2S exposure. However, there is a lack of detailed studies characterizing possible associations between the density of landfills and …

Impact Of Substance Use In Social Networks On Antiretroviral Therapy Adherence For Hiv-Positive Younger Men Who Have Sex With Men, Natascha Del Vecchio

Dissertations and Theses (Open Access)

The community of young men who have sex with men (YMSM) has higher rates of substance use than the general population and the use of alcohol, cannabis, and illicit drugs has been shown to have a negative impact on the HIV care continuum. Our first aim was to understand the prevalence of substance use in the community through the use of self-reported, RDS-II, and RDS-SS estimates. We used multivariable logistic and negative binomial GEE with QIC selection to determine the factors important to having a prescription and staying adherent, respectively. Selected variables were included with a subset of substance use …

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

Dissertations and 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 and 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 …

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

Dissertations and 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 …

Health Disparities Across Funcitonal Disability Groups, Katherine Sanches

Dissertations and 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 …

Covariate-Adaptive And Response-Adaptive Clinical Trial Designs, Lu Wang

Dissertations and Theses (Open Access)

Most of the research on Response-adaptive randomization(RAR) designs has been focused on clinical trials with a single endpoint. However modern clinical trials are often complex, with multiple competing objectives and multiple endpoints. We overcome the obstacles introduced by the large number of unknown parameters and the possible correlations between the multiple endpoints. We obtained the optimal allocation proportions for the following two optimization problems: (1) maximizing the power of the test of homogeneity with a xed sample size, and (2) minimizing the expected weighted number of failures with a fixed power. Further, we implemented these optimal allocations through response-adaptive randomization …

Understanding Spatial Language In Radiology: Representation Framework, Annotation, And Spatial Relation Extraction From Chest X-Ray Reports Using Deep Learning, Surabhi Datta, Yuqi Si, Laritza Rodriguez, Sonya E Shooshan, Dina Demner-Fushman, Kirk Roberts

Faculty, Staff and Student Publications

Radiology reports contain a radiologist's interpretations of images, and these images frequently describe spatial relations. Important radiographic findings are mostly described in reference to an anatomical location through spatial prepositions. Such spatial relationships are also linked to various differential diagnoses and often described through uncertainty phrases. Structured representation of this clinically significant spatial information has the potential to be used in a variety of downstream clinical informatics applications. Our focus is to extract these spatial representations from the reports. For this, we first define a representation framework based on the Spatial Role Labeling (SpRL) scheme, which we refer to as …

Astrocytes Rescue Neuronal Health After Cisplatin Treatment Through Mitochondrial Transfer., Krystal English, Krystal English

Dissertations and Theses (Open Access)

Abstract

Astrocytes rescue neuronal health after cisplatin treatment through mitochondrial transfer.

Author: Krystal English

Advisory Professor: Dr. Cobi J. Heijnen, Ph.D.

Chemotherapy-induced cognitive impairments are associated with neuronal mitochondrial dysfunction. Cisplatin, a commonly used chemotherapeutic, induces neuronal mitochondrial dysfunction in vivo and in vitro. Astrocytes are key players in supporting neuronal development, synaptogenesis, axonal growth, metabolism and, potentially, mitochondrial health. We tested the hypothesis that astrocytes transfer healthy mitochondria to neurons after cisplatin treatment to restore neuronal health.

We used an in vitro system in which astrocytes with Mito-mCherry-labeled mitochondria were co-cultured with primary cortical neurons or neuronal stem …

Bst2 Isoforms: Distribution And Potential Use In Cancer Therapeutics, Ahmed Muhsin

Dissertations and Theses (Open Access)

Identifying a cancer-specific cellular target is one of the key factors that can pave a “bench to the bedside” path of a target therapy. Bone marrow stromal cell antigen 2 (BST2) is a raft-associated type II transmembrane protein with an unusual topology. Analyses showed a variable degree of BST2 expression in most organs. Two research groups identified different BST2 isoforms of BST2 generated by posttranscriptional modification. In this research, I studied the long BST2 isoform’s distribution in breast tissue and B cell lines using the novel monoclonal antibody (MAb) LA5, an anti-BST2-long MAb. This approach revealed the expression of the …

Aging Lowers Pex5 Levels In Cortical Neurons In Male And Female Mouse Brains, Ndidi-Ese Uzor

Dissertations and Theses (Open Access)

Peroxisomes are small organelles with critical functions: lipid synthesis, breakdown of reactive oxygen species by antioxidant enzymes, and amino acid degradation. In the brain, peroxisomal lipids make up the myelin sheath. Brain peroxisomal dysfunction leads to lipid disruption or neurological consequences if key peroxisomal proteins are absent. Still, it is unclear how peroxisomes are affected in neurodegenerative diseases and in normal brain aging. This work examines peroxisomal markers in three settings: 1) in a neuronal and 2) animal model of Huntington disease (HD), where mutant huntingtin (mHtt), the causative protein in Huntington disease pathogenesis is expressed, and 3) in the …

Low-Dose Versus High-Dose Carfilzomib With Dexamethasone (S1304) In Patients With Relapsed-Refractory Multiple Myeloma, Sikander Ailawadhi, Rachael Sexton, Suzanne Lentzsch, Muneer H Abidi, Peter M Voorhees, Adam D Cohen, Eric M Rohren, Stephen Heitner, Kevin Kelly, Niklas J Mackler, David M Baer, Antje Hoering, Brian Durie, Robert Z Orlowski

Faculty, Staff and Students Publications

PURPOSE: Treatment of multiple myeloma has evolved tremendously and optimal utilization of available therapies will ensure maximal patient benefits.

PATIENTS AND METHODS: We report the Southwest Oncology Group randomized phase II trial (S1304) comparing twice weekly low-dose (27 mg/m

RESULTS: Among 143 enrolled patients, of whom 121 were eligible and analyzable, the overall response rate was 42.8%, with no significant difference between the arms (

CONCLUSIONS: This randomized trial did not support a benefit of fixed duration, twice weekly 56 mg/m

Molecular Mechanisms And Epidemiology Of Covid-19 From An Allergist’S Perspective, Koa Hosoki, Abhijit Chakraborty, Sanjiv Sur

Faculty, Staff and Students Publications

The global pandemic caused by the newly described severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has caused worldwide suffering and death of unimaginable magnitude from coronavirus disease 2019 (COVID-19). The virus is transmitted through aerosol droplets, and causes severe acute respiratory syndrome. SARS-CoV-2 uses the receptor-binding domain of its spike protein S1 to attach to the host angiotensin-converting enzyme 2 receptor in lung and airway cells. Binding requires the help of another host protein, transmembrane protease serine S1 member 2. Several factors likely contribute to the efficient transmission of SARS-CoV-2. The receptor-binding domain of SARS-CoV-2 has a 10- to 20-fold …

Prevalence Of Helicobacter Pylori Positive Non-Cardia Gastric Adenocarcinoma Is Low And Decreasing In A Us Population, Theresa H Nguyen, Niharika Mallepally, Tariq Hammad, Yan Liu, Aaron P Thrift, Hashem B El-Serag, Mimi C Tan

Faculty, Staff and Students Publications

BACKGROUND: Helicobacter pylori infection is an established causal factor for non-cardia gastric cancer. H. pylori negative gastric cancer prevalence among US patients is unclear.

METHODS: This retrospective cohort study examined H. pylori prevalence among consecutive patients with incident non-cardia gastric adenocarcinoma at the Houston VA Hospital (11/2007-10/2018). H. pylori positivity was defined by H. pylori on histopathology, positive antibody serology, stool antigen, or urea breath testing. We examined for trends in H. pylori negative gastric cancer based on year of diagnosis. Associations between histopathologic and cancer-related outcomes with H. pylori positivity were determined using regression models.

RESULTS: Of 91 patients …

Post-Registration Experience Of Nivolumab In Advanced Hepatocellular Carcinoma: An International Study, Petros Fessas, Ahmed Kaseb, Yinghong Wang, Anwaar Saeed, David Szafron, Tomi Jun, Sirish Dharmapuri, Abdul Rafeh Naqash, Mahvish Muzaffar, Musharraf Navaid, Uqba Khan, Chiehju Lee, Anushi Bulumulle, Bo Yu, Sonal Paul, Neil Nimkar, Dominik Bettinger, Francesca Benevento, Hannah Hildebrand, Tiziana Pressiani, Yehia I Abugabal, Nicola Personeni, Yi-Hsiang Huang, Lorenza Rimassa, Celina Ang, Thomas Marron, David J Pinato

Faculty, Staff and Students Publications

BACKGROUND: Nivolumab is Food and Drug Administration approved in sorafenib-experienced, advanced hepatocellular carcinoma (HCC). Post-registration data of treatment in a real-world setting is lacking.

PATIENTS AND METHODS: We performed an international, multicenter observational study to confirm safety and efficacy of nivolumab in 233 patients treated outside clinical trials from eight centers in North America, Europe and Asia.

RESULTS: Patients received nivolumab for Barcelona Clinic Liver Cancer stage C (n=191, 92.0%) and Child-Pugh (CP) A (n=158, 67.8%) or B (n=75, 32.2%) HCC as first (n=85, 36.5%) or second to fourth systemic therapy line …

Platypnea-Orthodeoxia Syndrome Caused By An Intracardiac Shunt, Sanket P Borgaonkar, Wilson W Lam, Mehdi Razavi, Dhaval R Parekh

Faculty, Staff and Students Publications

Platypnea-orthodeoxia syndrome, a rare condition characterized by posture-related dyspnea, is usually caused by an intracardiac shunt, hepatopulmonary syndrome, or shunting resulting from severe pulmonary disease. We report the case of a 33-year-old woman who presented with increasing dyspnea and oxygen desaturation when she sat up or arose. Our diagnosis was platypnea-orthodeoxia syndrome. A lead of a previously implanted pacemaker exacerbated a severe tricuspid regurgitant jet that was directed toward the patient's intra-atrial septum. Percutaneous closure of a small secundum atrial septal defect eliminated right-to-left shunting and substantially improved the patient's functional status. In addition to this case, we discuss this …

Profound And Redundant Functions Of Arcuate Neurons In Obesity Development, Canjun Zhu, Zhiying Jiang, Yuanzhong Xu, Zhao-Lin Cai, Qingyan Jiang, Yong Xu, Mingshan Xue, Benjamin R Arenkiel, Qi Wu, Gang Shu, Qingchun Tong

Children’s Nutrition Research Center Staff Publications

The current obesity epidemic faces a lack of mechanistic insights. It is known that the acute activity changes of a growing number of brain neurons rapidly alter feeding behaviour; however, how these changes translate to obesity development and the fundamental mechanism underlying brain neurons in controlling body weight remain elusive. Here, we show that chronic activation of hypothalamic arcuate GABAergic (GABA

Development Of A Ct Metal Artifact Management Algorithm For Proton Therapy Planning (Ampp) For Head And Neck Cancer Patients, Daniela Branco

Dissertations and Theses (Open Access)

Purpose: Dental amalgams (high Z materials) are common sources of artifacts in Head and Neck (HN) images. Commercial artifact reduction techniques have been offered, but many are impractical, produce inaccurate CT images or are not clinically available, thus not widely implemented. The goal of this work is to use CT gantry tilts to develop and evaluate a stereoscopic HN metal artifact management algorithm and investigate its improvement in proton treatment planning.

Methods: The in-house CT metal artifact management method for proton planning (AMPP) uses two angled CT scans to generate a single image set with no metal artifacts posterior …

Characterization Of Treatment Planning System Photon Beam Modeling Errors In Iroc Houston Phantom Irradiations, Mallory Glenn

Dissertations and Theses (Open Access)

In radiation therapy, proper commissioning of the treatment planning system’s (TPS) dose calculation algorithm is critical because any errors in this process impact all treatment plans prepared in the system. Previously, TPS errors have been identified as a major cause for poor phantom irradiation performance, which may also mean that patients are treated suboptimally. The purpose of this work was to investigate the TPS beam modeling developed by the radiotherapy community to understand where inconsistencies may arise, which variables are most susceptible to variations, and in what way changing these variables can alter dose calculations.

Using the Imaging and Radiation …

Bringing Til Therapy Beyond Melanoma: Advancing The Treatment Of Advanced Pancreatic And Ovarian Cancers, Donald Sakellariou-Thompson

Dissertations and Theses (Open Access)

The success of checkpoint blockade immunotherapy (CBI) has reinvigorated the cancer therapy field, particularly for advanced melanoma which has doubled the survival rates compared to 20 years ago. However, there are many solid tumor types that are yet to receive substantial benefit from this groundbreaking therapy, two of which are pancreatic cancer (PDAC) and ovarian cancer (OvCa). As such, the 5-year survival rate for PDAC and OvCa stand at 9% and 28% respectively. Despite the lack of efficacy of CBI so far, there is still evidence for the role of immune control in these cancers as evidenced by presence of …

Directed Evolution Of Macrocyclic Peptides For Inhibition Of Autophagy, Joshua Gray

Dissertations and Theses (Open Access)

In recent decades it has become increasingly clear that induction of autophagy plays an important role in the development of treatment resistance and dormancy in many cancer types. Chloroquine (CQ) and hydroxychloroquine (HCQ), two autophagy inhibitors in clinical trials, suffer from poor pharmacokinetics and high toxicity at therapeutic dosages. This has prompted intense interest in the development of targeted autophagy inhibitors to re-sensitize disease to treatment with minimal impact on normal tissue. We utilized Scanning Unnatural Protease Resistant (SUPR) mRNA display to develop macrocyclic peptides targeting the autophagy protein LC3. The resulting peptides bound LC3A and LC3B—two essential components of …

Investigating The Role Of Quaking In Antigen Uptake And Cross-Presentation By Dendritic Cells, Yating Li

Dissertations and Theses (Open Access)

Dendritic cells (DCs) are considered the most potent antigen presenting cells (APC) due to their superior capability of cross-presenting exogenous antigens to CD8⁺ T cell for strong adaptive immune responses. They internalize foreign antigens by phagocytosis, endocytosis or macropinocytosis, which are then processed in endosomal compartments and loaded onto MHC Class I molecules. However, the molecular mechanisms regulating exogenous antigen uptake and cross-presentation by DCs are not fully understood.

In this study, we discovered that an RNA-binding protein, Quaking (QKI) plays a pivotal role in antigen uptake by DCs. Our previous studies in neural stem cells and microglia have …

Active Magnetic Radiation Shielding For Long-Duration Human Spaceflight, Kristine Ferrone

Dissertations and Theses (Open Access)

Exploration of interplanetary space presents dramatic hazards to human survival.

Space radiation hazards outside the protection of the Earth’s magnetosphere can

produce both acute and chronic health risks and thus become limiting factors for

NASA’s planned mission to Mars by the 2030s. Radiation exposure on a Mars mission

is delivered primarily by high energy ions from galactic cosmic rays and moderate

energy protons from solar particle events. The chronic radiation dose due to galactic

cosmic rays on a typical Mars mission is on the order of 1 Sv, and additional acute

radiation dose from solar flares can reach over 4 …

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

Dissertations and 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 …

Investigating The Metabolic Progression Of Glioblastoma With Hyperpolarized Magnetic Resonance, Travis Salzillo

Dissertations and Theses (Open Access)

Rapid diagnosis and therapeutic monitoring of aggressive diseases such as glioblastoma (GBM) can improve patient survival by providing physicians the time to optimally deliver treatment. This includes early in development, while the tumor is still manageable, or following initial therapy, when alternative treatments should be considered. The main goal of this project was to determine whether metabolic imaging with hyperpolarized magnetic resonance spectroscopy (MRS) could detect changes in tumor progression more rapidly than conventional anatomic magnetic resonance imaging (MRI) in patient-derived GBM murine models. To comprehensively capture the dynamic nature of cancer metabolism, in vivo pyruvate-to-lactate conversion with hyperpolarized MRI, …

Elevated Cochlear Adenosine Causes Hearing Loss Via Adora2b Signaling, Jeanne Manalo

Dissertations and Theses (Open Access)

Over 538 million people in the world have been diagnosed with hearing loss (HL). Current treatments for the most common type of HL, sensorineural HL, are limited to hearing aids and cochlear implants with no FDA-drugs available. The hearing process demands an abundance of ATP and HL is often attributed to a disruption in this metabolic energy currency. Patients who lack adenosine deaminase (ADA), the enzyme that irreversibly metabolizes adenosine, have high levels of adenosine that yield severe health problems, including HL; however, the pathogenic mechanisms behind HL and adenosine remain elusive. Our lab has found a HL phenotype in …

Mechanistic Insights Into Vancomycin Resistance In Clostridioides Difficile, Ayesha Mahmood

Dissertations and Theses (Open Access)

C. difficile is a nosocomial, opportunistic pathogen that has become more hypervirulent over the last decade. Vancomycin is currently a frontline antibiotic for the treatment of C. difficile infections. Yet, strains of C. difficile are becoming non-susceptible to vancomycin. Emergence of the vancomycin non-susceptible phenotype has led to various questions including: What resistance elements are present that might contribute to the phenotype? Are these elements located on the chromosome or a plasmid? Where did these elements originate from? To address these questions, whole genome sequence analysis was performed to survey genes that may be involved in the vancomycin non-susceptible phenotype. …