Medicine and Health Sciences Commons^™

Smooth Muscle Hyperplasia Due To Acta2/Myh11 Mutations: Identification Of Novel Pathology And Pathways Leading To Aneurysms And Diverse Vascular Occlusive Diseases, Christina L. Papke

Dissertations & Theses (Open Access)

Missense mutations in smooth muscle cell (SMC) specific ACTA2 (á-actin) and MYH11 (â-myosin heavy chain) cause diffuse and diverse vascular diseases, including thoracic aortic aneurysms and dissections (TAAD) and early onset coronary artery disease and stroke. The mechanism by which these mutations lead to dilatation of some arteries but occlusion of others is unknown. We hypothesized that the mutations act through two distinct mechanisms to cause varied vascular diseases: a loss of function, leading to decreased SMC contraction and aneurysms, and a gain of function, leading to increased SMC proliferation and occlusive disease. To test this hypothesis, ACTA2 mutant SMCs …

Commissioning An Anthropomorphic Spine And Lung Phantom For Remote Dose Verification Of Institutions Participating In Rtog 0631, Douglas F. Caruthers

Dissertations & Theses (Open Access)

The RPC developed a new phantom to ensure comparable and consistent radiation administration in spinal radiosurgery clinical trials. This study assessed the phantom’s dosimetric and anatomic utility. The ‘spine phantom’ is a water filled thorax with anatomy encountered in spinal radiosurgery: target volume, vertebral column, spinal canal, esophagus, heart, and lungs. The dose to the target volume was measured with axial and sagittal planes of radiochromic film and thermoluminescent dosimeters (TLD). The dose distributions were measured with the radiochromic film calibrated to the absolute dose measured by the TLD. Four irradiations were administered: a four angle box plan, a seven …

Il-2 Regulation Of Il-24 Expression Leads To Growth Suppression Of Melanoma Cells, Emily Jen

Dissertations & Theses (Open Access)

Melanoma is known to be highly resistant to chemotherapy. Treatment with high dose IL-2 has shown significant clinical benefit in a minority of metastatic melanoma patients and has lead to long term survival in a few cases. However, this treatment is associated with excessive multiorgan toxicities, which severely limits its use. We hypothesize that one mechanism of effective IL-2 therapy is through the direct upregulation of IL-24 production in melanoma tumors and subsequent IL-24 mediated tumor growth suppression.

Five melanoma cell lines were treated with high dose recombinant hIL-2 at 1000U/ml. Three of the cell lines (A375, WM1341, WM793) showed …

An Assessment Of Obesity And Hyperphagia In Individuals With Smith-Magenis Syndrome, Carrie A. Crain

Dissertations & Theses (Open Access)

Smith-Magenis syndrome (SMS;OMIM# 182290) is a multiple congenital anomalies and mental retardation syndrome caused by a 3.7- Mb deletion on chromosome 17p11.2 or a mutation in the RAI1 gene. Although the majority of the SMS phenotype has been well described, limited studies are available describing growth patterns in SMS. There is some evidence that individuals with SMS develop obesity. Thus, this study aims to characterize the growth and potential influence of hyperphagia in a cohort of individuals with SMS. A retrospective chart review was conducted of 78 individuals with SMS through Baylor College of Medicine (BCM) at Texas Children¡¯s Hospital …

Mechanism-Based Strategies To Enhance The Actions Of A, Fabiola C. Gomez

Dissertations & Theses (Open Access)

Heat shock protein 90 (HSP90) is an abundant molecular chaperone that regulates the functional stability of client oncoproteins, such as STAT3, Raf-1 and Akt, which play a role in the survival of malignant cells. The chaperone function of HSP90 is driven by the binding and hydrolysis of ATP. The geldanamycin analog, 17-AAG, binds to the ATP pocket of HSP90 leading to the degradation of client proteins. However, treatment with 17-AAG results in the elevation of the levels of antiapoptotic proteins HSP70 and HSP27, which may lead to cell death resistance. The increase in HSP70 and HSP27 protein levels is due …

Type I Insulin-Like Growth Factor Receptor Tyrosine Kinase As A Molecular Target In Mantle Cell Lymphoma, Deeksha Vishwamitra

Dissertations & Theses (Open Access)

Mantle cell lymphoma (MCL) is an aggressive B-cell lymphoid malignancy representing 5-10% of all non-Hodgkin’s lymphomas. It is distinguished by the t(11;14)(q13;q32) chromosomal translocation that juxtaposes the proto-oncogene CCND1, which encodes cyclin D1 at 11q13 to the IgH gene at 14q32. MCL patients represent about 6% of all new cases of Non-Hodgkin’s lymphomas per year or about 3,500 new cases per year. MCL occurs more frequently in older adults – the average age at diagnosis is the mid-60s with a male-to-female ratio of 2-3:1. It is typically characterized by the proliferation of neoplastic B-lymphocytes in the mantle zone of the …

A Randomized Trial Of Bilevel Positive Airway Pressure Device And High Flow Oxygen For Persistent Dyspnea In, David Hui

Dissertations & Theses (Open Access)

Background: Dyspnea is a common and distressing symptom among patients with advanced cancer. The role of bilevel positive airway pressure (BIPAP) and Vapotherm in the relief of dyspnea have not been well defined. We aimed to determine and to compare the efficacy of BIPAP and VapoTherm for cancer related dyspnea.

Methods: In this randomized, open-label, crossover study, we randomly assigned advanced cancer patients with persistent dyspnea >=3/10 to either Vapotherm for 2 hours followed by BiPAP for 2 hours, or BiPAP followed by Vaptherm. A variable washout period was instituted between interventions. The primary end point was change in numeric …

Workload And Performance Factors Associated With Multimedia Job Aids For Community Health Workers, Jose F. Florez-Arango

Dissertations & Theses (Open Access)

This dissertation focuses on factors of multimedia job aids that modify workload, protocol adherence and clinical errors in community health workers. Literature shows that community health workers performance is not acceptable even with support of paper job aids. There are cognitive theories that try to explain reasons why the performance of community health workers is poor regardless of the access to paper based-job aid. Based on cognitive science and multimedia design theories an intervention was designed to compare alternative representations for the information contained on paper job aids and the capability of this new designed job aids to enhance community …

Biomedical Language Understanding And Extraction (Blue-Text): A Minimal Syntactic, Semantic Method, Parsa Mirhaji

Dissertations & Theses (Open Access)

Clinical text understanding (CTU) is of interest to health informatics because critical clinical information frequently represented as unconstrained text in electronic health records are extensively used by human experts to guide clinical practice, decision making, and to document delivery of care, but are largely unusable by information systems for queries and computations. Recent initiatives advocating for translational research call for generation of technologies that can integrate structured clinical data with unstructured data, provide a unified interface to all data, and contextualize clinical information for reuse in multidisciplinary and collaborative environment envisioned by CTSA program. This implies that technologies for the …

Understanding Nurse Created Cognitive Artifacts: Personally-Created-Cognitive-Artifacts As External Representations Of Distributed Cognition, Sharon Mclane

Dissertations & Theses (Open Access)

Manuscript 1: “Conceptual Analysis: Externalizing Nursing Knowledge”

We use concept analysis to establish that the report tool nurses prepare, carry, reference, amend, and use as a temporary data repository are examples of cognitive artifacts. This tool, integrally woven throughout the work and practice of nurses, is important to cognition and clinical decision-making. Establishing the tool as a cognitive artifact will support new dimensions of study. Such studies can characterize how this report tool supports cognition, internal representation of knowledge and skills, and external representation of knowledge of the nurse.

Manuscript 2: “Research Methods: Exploring Cognitive Work”

The purpose of this …

Regulation Of Survivin Gene Expression In The Human Endometrium And Endometrial Cancer, Nancy H. Nabilsi

Dissertations & Theses (Open Access)

In the United States, endometrial cancer is the leading cancer of the female reproductive tract. There are 40,100 new cases and 7,470 deaths from endometrial cancer estimated for 2008 (47). The average five year survival rate for endometrial cancer is 84% however, this figure is substantially lower in patients diagnosed with late stage, advanced disease and much higher for patients diagnosed in early stage disease (47). Endometrial cancer (EC) has been associated with several risk factors including obesity, diabetes, hypertension, previously documented occurrence of hereditary non-polyposis colorectal cancer (HNPCC), and heightened exposure to estrogen (25). As of yet, there has …

Characterizing, Assessing And Improving Healthcare Referral Communication, Adol Esquivel

Dissertations & Theses (Open Access)

Similar to other health care processes, referrals are susceptible to breakdowns. These breakdowns in the referral process can lead to poor continuity of care, slow diagnostic processes, delays and repetition of tests, patient and provider dissatisfaction, and can lead to a loss of confidence in providers. These facts and the necessity for a deeper understanding of referrals in healthcare served as the motivation to conduct a comprehensive study of referrals.

The research began with the real problem and need to understand referral communication as a mean to improve patient care. Despite previous efforts to explain referrals and the dynamics and …

Unsupervised Indexing Of Medline Articles Through Graph-Based Ranking, Jorge R. Herskovic

Dissertations & Theses (Open Access)

The biomedical literature is extensively catalogued and indexed in MEDLINE. MEDLINE indexing is done by trained human indexers, who identify the most important concepts in each article, and is expensive and inconsistent. Automating the indexing task is difficult: the National Library of Medicine produces the Medical Text Indexer (MTI), which suggests potential indexing terms to the indexers. MTI’s output is not good enough to work unattended. In my thesis, I propose a different way to approach the indexing task called MEDRank. MEDRank creates graphs representing the concepts in biomedical articles and their relationships within the text, and applies graph-based ranking …

The Multiple Location Time Weighted Index: Using Patient Activity Spaces To Calculate Primary Care Service Areas, Jennifer Lynn Rankin

Dissertations & Theses (Open Access)

Geographic health planning analyses, such as service area calculations, are hampered by a lack of patient-specific geographic data. Using the limited patient address information in patient management systems, planners analyze patient origin based on home address. But activity space research done sparingly in public health and extensively in non-health related arenas uses multiple addresses per person when analyzing accessibility. Also, health care access research has shown that there are many non-geographic factors that influence choice of provider. Most planning methods, however, overlook non-geographic factors influencing choice of provider, and the limited data mean the analyses can only be related to …

Developing A Method For Identifying And Reducing Functional Discrepancies Of Information Systems, Jung-Wei Chen

Dissertations & Theses (Open Access)

Currently more than half of Electronic Health Record (EHR) projects fail. Most of these failures are not due to flawed technology, but rather due to the lack of systematic considerations of human issues. Among the barriers for EHR adoption, function mismatching among users, activities, and systems is a major area that has not been systematically addressed from a human-centered perspective. A theoretical framework called Functional Framework was developed for identifying and reducing functional discrepancies among users, activities, and systems. The Functional Framework is composed of three models – the User Model, the Designer Model, and the Activity Model. The User …

Nanoparticle Agglomerates For Pulmonary Drug Delivery, Rohan Bhavane

Dissertations & Theses (Open Access)

The Pulmonary route has been traditionally used to treat diseases of the respiratory tract. However, important research within the last two decades have shown that in addition to treating local diseases, a wide range of systemic diseases can be treated by delivering drugs to the lungs. The recent FDA approval to market Exubera, an inhalable form of insulin developed by Pfizer, to treat Diabetes, may just be the stepping stone that the pharmaceutical industry needs to market other drugs to treat systemic diseases via the lungs. However, this technology still needs repeated drug doses to control glucose levels, as the …

The Interaction Between Internal And External Information On Relational Data Search, Yang Gong

Dissertations & Theses (Open Access)

People often use tools to search for information. In order to improve the quality of an information search, it is important to understand how internal information, which is stored in user’s mind, and external information, represented by the interface of tools interact with each other. How information is distributed between internal and external representations significantly affects information search performance. However, few studies have examined the relationship between types of interface and types of search task in the context of information search.

For a distributed information search task, how data are distributed, represented, and formatted significantly affects the user search performance …

Understanding Interruptions In Healthcare: Developing A Model, Juliana J. Brixey

Dissertations & Theses (Open Access)

Developing a Model Interruption is a known human factor that contributes to errors and catastrophic events in healthcare as well as other high-risk industries. The landmark Institute of Medicine (IOM) report, To Err is Human, brought attention to the significance of preventable errors in medicine and suggested that interruptions could be a contributing factor. Previous studies of interruptions in healthcare did not offer a conceptual model by which to study interruptions. As a result of the serious consequences of interruptions investigated in other high-risk industries, there is a need to develop a model to describe, understand, explain, and predict interruptions …

Does The Message Matter? Enhancing Patient Adherence Through Persuasive Messages, Muhammad F. Walji

Dissertations & Theses (Open Access)

To improve health and reduce costs, we need to encourage patients to make better healthcare decisions. Many informatics interventions are aimed at improving health outcomes by influencing patient behavior. However, we know little about how the content of a message in these interventions can influence a health-related decision. In this research we formulate a conceptual model to help explain and guide the design of “persuasive messages”, those which can change and influence patient behavior. We apply the conceptual model to design persuasive appointment reminder messages using humancentered design principles. Finally, we empirically test our hypotheses in a randomized controlled trial …

Cognitive Impact Of Interactive Multimedia, Yanko F. Michea,

Dissertations & Theses (Open Access)

Technology has been gradually introduced in heath education. One of the most attractive features of this technology-based education is the use of multimedia. In this article we explore the research evidence about the role that multimedia is playing in education. From that analysis we describe the most relevant features of this technology to prepare a common ground of discussion about the evaluation of its impact on educational outcomes. As part of this analysis, we organize current research evidence on the use of technology in medical education, distinguishing diverse variables involved in the process, like knowledge (declarative, procedural), learner characteristics, curricular …

Effects Of Information Display On The Construction Of Clinician Mental Models, Constance M. Johnson

Dissertations & Theses (Open Access)

Objective: To determine how a clinician’s background knowledge, their tasks, and displays of information interact to affect the clinician’s mental model.

Design: Repeated Measure Nested Experimental Design

Population, Sample, Setting: Populations were gastrointestinal/internal medicine physicians and nurses within the greater Houston area. A purposeful sample of 24 physicians and 24 nurses were studied in 2003.

Methods: Subjects were randomized to two different displays of two different mock medical records; one that contained highlighted patient information and one that contained non-highlighted patient information. They were asked to read and summarize their understanding of the patients aloud. Propositional analysis was used to …

A Process For Achieving Comparable Data From Heterogeneous Databases, Rachel L. Richesson

Dissertations & Theses (Open Access)

The current state of health and biomedicine includes an enormity of heterogeneous data ‘silos’, collected for different purposes and represented differently, that are presently impossible to share or analyze in toto. The greatest challenge for large-scale and meaningful analyses of health-related data is to achieve a uniform data representation for data extracted from heterogeneous source representations. Based upon an analysis and categorization of heterogeneities, a process for achieving comparable data content by using a uniform terminological representation is developed. This process addresses the types of representational heterogeneities that commonly arise in healthcare data integration problems. Specifically, this process uses a …