Medicine and Health Sciences Commons^™

Development And Implementation Of An Anthropomorphic Head & Neck Phantom For The Assessment Of Proton Therapy Treatment Procedures, Daniela Branco

Dissertations and Theses (Open Access)

Proton therapy has been used to treat cancer for more than 50 years, and over the past decade, its use has grown rapidly. One of the main goals of modern radiation therapy is to deliver a high dose to the planning target volume (PTV) with minimal exposure and damage to the surrounding healthy tissue. Protons offer a unique advantage over photon radiotherapy in that they deposit dose over a finite range, in contrast to the more gradual energy deposition of photon and electron beams. At present, 23 proton centers are in operation in the United States and another 13 centers …

Define The Epigenetic Profiles And Subtype-Specific Genes Of Breast Cancer, Wenqian Li

Dissertations and Theses (Open Access)

Molecular profiling has identified 5 distinct subtypes of breast cancer, luminal A, luminal B, HER2-enriched, basal-like, and claudin-low breast cancer. These 5 subtypes correlate with hormone response, patient prognosis, and response to therapy. Although steady state gene expression patterns have been explored using expression microarrays, very little is known about the initial, disease-driving transcriptional changes in these cancers or epigenetic changes associated with the differential gene expression signatures. Defining these changes may provide new insights into the mechanisms by which these subtypes arise, as well as new avenues for breast cancer prevention, diagnosis, and treatment. Using Chromatin Immunoprecipitation sequencing and …

Interrogating Dux4 Mrna 3′ End Processing, Natoya J. Peart

Dissertations and Theses (Open Access)

Double Homeobox 4, Dux4, is the leading candidate gene for Facioscapulohumeral Dystrophy (FSHD). FSHD is the third most common muscular dystrophy, and is characterized by progressive muscle weakness primarily in the upper body. In individuals diagnosed with FSHD, Dux4 is inappropriately expressed in somatic cells due to two conditions. The first is hypomethylation of the subtelomeric D4Z4 repeats on chromosome 4. Each D4Z4 repeat on chromosome 4 is 3.3kb in length and contains the open reading frame for Dux4. Hypomethylation of the D4Z4 repeats primarily occurs due to contraction of the repeats from 11-100 (typical numbers in the healthy population) …

Tnf Signaling During Tissue Damage-Induced Nociceptive Sensitization In Drosophila, Juyeon Jo

Dissertations and Theses (Open Access)

Tumor necrosis factor (TNF) signaling is required for inflammatory nociceptive sensitization in both Drosophila and vertebrates. In Drosophila larval model of nociceptive sensitization, UV irradiation in results in epidermal apoptosis and thermal allodynia. TNF/Eiger is produced from dying epidermal cells and acts its receptor in nociceptive sensory neurons to induce thermal allodynia. Inhibition of TNF signaling results in attenuation of nociceptive sensitization whereas epidermal apoptosis still occurs in the absence of TNF. Major gaps in this model are the precise relationship between apoptotic cell death and production of TNF/Eiger, downstream signaling mediators for TNFR/Wengen, and target genes that alter nociceptive …

Potentially Inappropriate Medication Use In Older Patient With Breast And Colorectal Cancer, Meghan S. Karuturi

Dissertations and Theses (Open Access)

Our objective was to determine predictors of potentially inappropriate medication (PIM) use and its impact on outcomes (including ER visits, hospitalization, all cause death, and composite of three) in breast and colorectal cancer patients receiving chemotherapy. We used data from the SEER database linked to Medicare claims. Our cohort included patients ≥ 66 years diagnosed with of Stage II/III breast or colorectal cancer between 7/1/2007-12/31/2009. Baseline PIM was defined using the Drugs to Avoid in the Elderly list (DAE) or Beers criteria. Univariate and multivariable logistic regression were used to determine the associations of baseline PIMs with different covariates. Event-free …

An Automated Syringe Pump System For Improving The Reproducibility Of Dynamic Hyperpolarized Mri Phantoms, Harlee G. Harrison

Dissertations and Theses (Open Access)

AN AUTOMATED SYRINGE PUMP SYSTEM FOR IMPROVING THE REPRODUCIBILITY OF DYNAMIC HYPERPOLARIZED MRI PHANTOMS

Harlee Grace Harrison, B.S.

Advisory Professor: James Bankson, Ph.D.

Magnetic Resonance Imaging (MRI) is a powerful tool in the diagnosis of cancer due to its ability to provide good soft tissue contrast and image resolution without the use of ionizing radiation. The use of hyperpolarized pyruvate as a contrast agent for tumor metabolism during MR scans has the potential to provide information about tumor metabolism in vivo that is not available from traditional imaging measurements or any other method. Hyperpolarization is achieved through dynamic nuclear polarization. …

Measurement Of The Electron Return Effect Using Presage Dosimeter, Gye Won Choi

Dissertations and Theses (Open Access)

MR-guided radiation therapy (MRgRT) provides benefits such as superior soft tissue contrast, no imaging dose, and functional imaging capacities, but it also has concerns to be addressed. The electron return effect (ERE) refers to dose enhancement at the interface between different media, caused when radiation is delivered in the magnetic field. The ERE poses clinical concerns in MRgRT because it significantly enhances the dose at interfaces, and the intensity and pattern of the dose enhancement depends on many factors. The ERE results in a complex pattern of dose enhancement over a three-dimensional (3D) volume around tissue interfaces inside the patient …

Epigenetic Modulation In Braf Mutated Metastatic Colorectal Cancer, Van Morris

Dissertations and Theses (Open Access)

Introduction: BRAF V600E mutations are associated with poor clinical outcomes for patients with metastatic colorectal cancer (mCRC). Unlike other tumors with the same mutation, BRAF inhibitors are ineffective as monotherapy. CRC tumors with BRAF V600E mutations are associated with global hypermethylation, which may turn off tumor suppressor gene expression. We studied demethylation in BRAF V600E mCRC to restore sensitivity to BRAF inhibitors.

Methods: Tumor databanks were investigated for genes differentially expressed according to BRAF mutation status to identify genes which may be particularly susceptible to epigenetic influence. Mouse xenograft models of BRAFV600E mCRC were treated with vemurafenib or azacitidine, alone …

The Immune Microenvironment Of Microsatellite Instable Endometrial Cancer, Janelle B. Pakish

Dissertations and Theses (Open Access)

Limited treatment options are available for patients with advanced and recurrent endometrial cancer (EC) should standard chemotherapy fail. Recent studies in other tumor types have shown that tumors with high microsatellite instability (MSI-H) have increased immunogenicity and response to immunotherapy treatments compared to microsatellite stable (MSS) tumors. Patients with MSI-H EC may also benefit from these therapies; however, the tumor immune microenvironment in MSI-H EC has not yet been well described.

In order to evaluate the immune microenvironment of MSI-H EC, multiple approaches were used, including analysis of large publically available datasets and detailed characterization of patient tumor samples. Uterine …

Employing T Cells For Antigen Presentation: Role Of Ny-Eso-1+ T-Apc Vaccine In Multiple Myeloma, Krina K. Patel

Dissertations and Theses (Open Access)

Introduction: Cellular therapy has shown great potential in early phase clinical trials with persistence of effector cells appearing to lead to improved outcomes. Combined immunotherapy with NY-ESO-1⁺ CAR T cells (TCR mimetic) and an NY-ESO-1 specific T-APC vaccine in myeloma patients may lead to enhanced anti-myeloma efficacy due to improved persistence of the CAR T cells.

Materials and Methods: Using the Sleeping Beauty transposon/transposase system, an NY-ESO-1⁺ TCR and CAR were created as effector cells. Vaccine was produced by electroporation of the NY-ESO-1 gene into T cells to make T cell antigen presenting cells (T-APC). Costimulatory …

Understanding The Mechanism And Extent Of Vlse Recombination In Borrelia Burgdorferi Using Next-Generation Sequencing, Surabhi Tyagi

Dissertations and Theses (Open Access)

B. burgdorferi, the causative agent of Lyme disease, have an elaborate antigenic variation system that involves varying the sequence of vlsE. Previous studies have shown that vlsE antigenic variation occurs continuously inside mammalian hosts. Variation has not been shown previously to occur in in vitro or in ticks. We hypothesized that the induction of vlsE recombination requires contact with dense arrays of host tissue cells and/or ECM components. To test this hypothesis, two methods, quantitative PCR and high-throughput sequencing were used determine the extent and nature of vlsE recombination within mouse tissues and in vitro model systems. Using these …

Novel Mechanisms Of Β-Adrenergic Signaling In Prostate Cancer Progression, Mohit Hulsurkar

Dissertations and Theses (Open Access)

Prostate cancer is the second leading cause of cancer death among American men. The American Cancer Society estimates that 180,890 men will be will be diagnosed with prostate cancer in 2016 in the USA. (http://www.cancer.org/cancer/prostatecancer/detailedguide/prostate-cancer-key-statistics). Androgen deprivation therapy (ADT) is the standard treatment for early stage prostate cancer. But most patients relapse with aggressive variants of prostate cancer, with survival time between 1-3 years. In order to develop cure for such aggressive variants of prostate cancer, our present understanding of the mechanisms underlying its progression needs to be advanced.

Recently, it has been found that activation of β-adrenergic signaling pathway …

Encapsulated Contrast Agent Markers For Mri-Based Post-Implant Dosimetry, Tze Yee Lim

Dissertations and Theses (Open Access)

Low-dose-rate prostate brachytherapy involves the implantation of tiny radioactive seeds into the prostate to treat prostate cancer. The current standard post-implant imaging modality is computed tomography (CT). On CT images, the radioactive seeds can be distinctively localized but delineation of the prostate and surrounding soft tissue is poor. Magnetic resonance imaging (MRI) provides better prostate and soft tissue delineation, but seed localization is difficult. To aid with seed localization, MRI markers with encapsulated contrast agent that provide positive-contrast on MRI images (Sirius MRI markers; C4 Imaging, Houston, TX) have been proposed to be placed adjacent to the negative-contrast seeds. This …

Coronary-Cameral Fistula Caused By Guidewire Trauma And Resolved By Coil Embolization, Suvro Banerjee, Soumya Patra

The Texas Heart Institute Journal

A 57-year-old woman presented with effort angina. A coronary angiogram revealed critical 2-vessel disease, for which she subsequently underwent percutaneous coronary intervention. During angioplasty, a coronary guidewire-inadvertently passed into the right ventricle through the septal branches of the posterior descending coronary artery-caused a coronary artery-to-right ventricular fistula. This fistula was successfully closed percutaneously by coil embolization. To our knowledge, this is the first report of a case in which a coronary artery-to-right ventricular fistula caused by a guidewire was managed successfully by coil embolization.

Advanced Interventional Therapy For Radiation-Induced Cardiovascular Disease, Daisy C Nieto

The Texas Heart Institute Journal

This report describes the case of a 61-year-old woman who presented with dyspnea, aortic stenosis, and coronary artery disease-typical side effects of radiation therapy for Hodgkin lymphoma. A poor candidate for surgery, she underwent successful high-risk percutaneous coronary intervention and subsequent transcatheter aortic valve replacement. This report highlights some of the cardiovascular-specific sequelae of radiation therapy for cancer treatment; in addition, possible directions for future investigations are discussed.

Precision Medicine Informatics, Lewis J Frey, Elmer V Bernstam, Joshua C Denny

Faculty, Staff and Student Publications

No abstract provided.

Emergency Coronary Artery Bypass Grafting: Indications And Outcomes From 2003 Through 2013, Erin M Schumer, John H Chaney, Jaimin R Trivedi, Paul L Linsky, Matthew L Williams, Mark S Slaughter

The Texas Heart Institute Journal

Emergency coronary artery bypass grafting (CABG) is associated with increased in-hospital mortality rates and adverse events. This study retrospectively evaluated indications and outcomes in patients who underwent emergency CABG.

The Society of Thoracic Surgeons database for a single center (Jewish Hospital) was queried to identify patients undergoing isolated CABG. Univariate analysis was performed.

From January 2003 through December 2013, 5,940 patients underwent CABG; 212 presented with emergency status. A high proportion of female patients (28.2%) underwent emergency surgery. Emergency CABG patients experienced high rates of intra-aortic balloon pump support, bleeding, dialysis, in-hospital death, and prolonged length of stay. The proportion …

Two Cases Of Transcatheter Closure Of Central Aortopulmonary Shunts: One With An Amplatzer Duct Occluder Ii And One With An Amplatzer Vascular Plug I, Ahmet Celebi, Ilker Kemal Yucel, Sevket Balli, Mehmet Kucuk

The Texas Heart Institute Journal

When total correction is not possible in infants who have a cyanotic congenital heart disease, creation of a palliative aortopulmonary shunt is essential. A central aortopulmonary shunt is preferable, because of its technical and hemodynamic advantages. Overcirculation, thrombosis, and stenosis of the shunt are the main postoperative sequelae that necessitate urgent reintervention. Percutaneous transcatheter closure of aortopulmonary shunts can eliminate the need for reoperation and substantially decrease postoperative morbidity and mortality rates. We report our successful transcatheter closures of central aortopulmonary shunts in a 3-month-old infant and a 15-year-old girl, with use of an Amplatzer Duct Occluder II and an …

Fresh Autologous Pericardium To Reconstruct The Pulmonary Valve At The Annulus When Tetralogy Of Fallot Requires A Transannular Patch At Midterm, Shantanu Pande, Jugal K Sharma, C R Siddartha, Anubhav Bansal, Surendra K Agarwal, Prabhat Tewari, Aditya Kapoor

The Texas Heart Institute Journal

Tetralogy of Fallot often requires reconstruction of the right ventricular outflow tract with a transannular patch (TAP), but this renders the pulmonary valve incompetent and eventually leads to right ventricular dysfunction.

We retrospectively evaluated the efficacy of a reconstructed pulmonary valve and annulus in 70 patients who underwent, from December 2006 through December 2010, complete correction of tetralogy of Fallot. We divided the 70 patients into 2 groups in accordance with whether they required (n=50) or did not require (n=20) a TAP. We used autologous untreated pericardium to fashion the TAP and to create both an annulus of the correct …

Endocarditis And Incomplete Endothelialization 12 Years After Amplatzer Septal Occluder Deployment, Allan K Nguyen, Brian A Palafox, Joanne P Starr, Richard N Gates, Farbouch Berdjis

The Texas Heart Institute Journal

A 4-year-old boy had a 15-mm atrial septal defect repaired percutaneously with use of an Amplatzer Septal Occluder. At age 16 years, he presented with a week's history of fever, chills, dyspnea, fatigue, and malaise. Cultures grew methicillin-sensitive Staphylococcus aureus. A transesophageal echocardiogram showed a 1.25 × 1.5-cm pedunculated mass on the left aspect of the atrial septum just superior to the mitral valve, and a smaller vegetation on the right inferior medial aspect of the septum. At surgery, visual examination of both sides of the septum revealed granulation tissue, the pedunculated mass, the small vegetation, and exposed metal …

Skepticism, The Trained Eye, And The Telltale Clue, Ethan A Natelson

The Texas Heart Institute Journal

No abstract provided.

Does Myocardial Necrosis Occur In Rhabdomyolysis?, Gabriel M Aisenberg, Herbert L Fred

Faculty, Staff and Student Publications

No abstract provided.

Implications Of Computational Cognitive Models For Information Retrieval, Joshua Caleb Goodwin

Dissertations and Theses (Open Access)

This dissertation explores the implications of computational cognitive modeling for information retrieval. The parallel between information retrieval and human memory is that the goal of an information retrieval system is to find the set of documents most relevant to the query whereas the goal for the human memory system is to access the relevance of items stored in memory given a memory probe (Steyvers & Griffiths, 2010).

The two major topics of this dissertation are desirability and information scent. Desirability is the context independent probability of an item receiving attention (Recker & Pitkow, 1996). Desirability has been widely utilized in …

Information Processing Speed Impairment After Stroke, A Descriptive Study, Susan Alderman

Dissertations and Theses (Open Access)

Background Information processing speed (IPS) is an elemental cognitive function impacting multiple other functions including memory, attention, and executive function, and academic skills like arithmetic, reading and writing. However, little research has been done on IPS impairment in acute stroke. This article compares the frequency and severity of IPS impairment in mild and moderate stroke and its impact on quality of life.

Methods The longitudinal study of patients with mild stroke (NIHSS

Results Using linear mixed model regression, similar frequency and severity of IPS and memory impairments were noted, regardless of stroke severity, in the sample of 30 patients (60% …

Psychometric Performance Of The Arabic Versions Of The Cancer Behavior Inventory‐Brief And The Functional Assessment Of Cancer Therapy‐Breast In Saudi Arabia, Maaidah M. Algamdi Msn

Dissertations and Theses (Open Access)

Background: Arabic is the mother tongue of 26 countries, including Saudi Arabia where cancer is the fourth leading cause of death. Cancer is a sensitive issue in the Arabic population and a clear understanding of patients’ perceptions of self-efficacy for coping with cancer and quality of life helps assess interventions designed to facilitate optimal patient outcomes. In preliminary studies, the Cancer Behavior Inventory-Brief (CBI-B) was translated and back translated between English and Arabic, and reviewed for translational validity by an expert panel. The Arabic version of the CBI-B (CBI-BA) had acceptable evidence of translational validity with an overall translational validity …

Regulation Of The Escrt Function Of Alix, Sheng Sun

Dissertations and Theses (Open Access)

The ESCRT (endosomal sorting complex required for transport) is an evolutionary conserved membrane remodeling machinery that performs membrane invagination and abscission. ALIX is a widely expressed adaptor protein that is critically involved in three classical ESCRT-mediated processes, including MVB (multivesicular body) sorting, cytokinetic abscission and retroviral budding. Previous studies have demonstrated that ALIX involvement in these ESCRT-mediated processes requires ALIX interaction with the ESCRT-III component CHMP4 as well as a cargo protein. However, the native form of ALIX contains a default intramolecular interaction between N-terminal Bro1 domain and C-terminal PRD (proline-rich domain), leading to a closed conformation of ALIX that …

Ethnic Identity And Teratogenic Risk Perceptions, Katie M. Chan

Dissertations and Theses (Open Access)

Elevated perceptions of teratogenic risk can cause anxiety and confusion among pregnant women. To assess whether ethnic identity and demographic factors can influence teratogenic risk perceptions, 194 pregnant women in Houston were surveyed using the Multigroup Ethnic Identity Measure (MEIM) and visual analog scales to quantify perceptions of teratogenic risk for common exposures during pregnancy. Overall, participants estimated an elevated baseline risk of 25% for birth defects among the general population. In addition, participants overestimated birth defect risks for specific exposures, such as alcohol and marijuana. Based on the MEIM scores, ethnic identity was not significantly associated with teratogenic risk …

Effect Of Photographs Of Visible Genetic Conditions On Quality Of Life Perceptions, Christina Falugi

Dissertations and Theses (Open Access)

Historically, medical photographs are used to demonstrate dysmorphic features and characteristic presentations of genetic conditions. Traditional, pictorial depictions of genetic conditions typically involve nude subjects against walls to emphasize their features. These stark, black and white photographs may negatively influence students’ perceptions of the depicted individual. Natural photographs which include individuals in non-clinical environments may impact perceptions. To assess the influence of photographs on a viewer’s perception, 649 students from medical, nursing, genetic counseling and dental programs were surveyed in a cross-over study. Students were randomized to view a traditional or a natural photograph of three distinct genetic conditions followed …

Integration Of Multi-Platform High-Dimensional Omic Data, Xuebei An

Dissertations and Theses (Open Access)

The development of high-throughput biotechnologies have made data accessible from different platforms, including RNA sequencing, copy number variation, DNA methylation, protein lysate arrays, etc. The high-dimensional omic data derived from different technological platforms have been extensively used to facilitate comprehensive understanding of disease mechanisms and to determine personalized health treatments. Although vital to the progress of clinical research, the high dimensional multi-platform data impose new challenges for data analysis. Numerous studies have been proposed to integrate multi-platform omic data; however, few have efficiently and simultaneously addressed the problems that arise from high dimensionality and complex correlations.

In my dissertation, I …

Genomic Drivers Of Cutaneous Squamous Cell Carcinoma Development, Vida Chitsazzadeh

Dissertations and Theses (Open Access)

Skin cancer is the most common malignancy in humans. Annually, in U.S. there are over 3 million cases with an estimated overall economic impact of $2 billion. Cutaneous Squamous Cell Carcinoma (cuSCC) comprises 15-20% of all skin cancers. cuSCC has the best-defined progression from a distinct precancerous lesion, the Actinic Keratosis (AK), to invasive cuSCC. Destructive therapies for AK treatment must be used repetitively, causing significant morbidity. There is a tremendous need for targeted diagnostics and therapy for AKs, representing an important opportunity for secondary skin cancer prevention. Our knowledge of the molecular and cellular events that lead to the …