Medicine and Health Sciences Commons^™

Implementation Of An Anthropomorphic Phantom For The Evaluation Of Proton Therapy Treatment Procedures, Ryan L. Grant

Dissertations & Theses (Open Access)

With an increasing number of institutions offering proton therapy, the number of multi-institutional clinical trials involving proton therapy will also increase in the coming years. The Radiological Physics Center monitors sites involved in clinical trials through the use of site visits and remote auditing with thermoluminescent dosimeters (TLD) and mailable anthropomorphic phantoms. Currently, there are no heterogeneous phantoms that have been commissioned to evaluate proton therapy. It was hypothesized that an anthropomorphic pelvis phantom can be designed to audit treatment procedures (patient simulation, treatment planning and treatment delivery) at proton facilities to confirm agreement between the measured dose and calculated …

The Role Of Map Kinases On The Functional Heterogeneity Of Human Cd8+ T Cell Maturation Subsets, Tae Kon Kim

Dissertations & Theses (Open Access)

While prior studies have focused on naïve (CD45RA+CD27+) and early stage memory (CD45RA-CD27+) CD8+ T cells, late memory CD8+ T cells (CD45RA+CD27) have received less interest because this subset of T cells is generally recognized as effectors, which produce IFNγ (but no IL-2) and perforin. However, multiple studies suggest that late memory CD8+ T cells may provide inadequate protection in infectious diseases and cancer models.

To better understand the unique function of late memory CD8+ T cells, I optimized multi-color flow cytometry techniques to assess the cytokine production of each human CD8+ T cell maturation subset. I demonstrated that late …

Measurement Of The Vascular Input Function In Mice For Dce-Mri, Dustin K. Ragan

Dissertations & Theses (Open Access)

DCE-MRI is an important technique in the study of small animal cancer models because its sensitivity to vascular changes opens the possibility of quantitative assessment of early therapeutic response. However, extraction of physiologically descriptive parameters from DCE-MRI data relies upon measurement of the vascular input function (VIF), which represents the contrast agent concentration time course in the blood plasma. This is difficult in small animal models due to artifacts associated with partial volume, inflow enhancement, and the limited temporal resolution achievable with MR imaging. In this work, the development of a suite of techniques for high temporal resolution, artifact resistant …

Cip4 And Src In Promoting The Migration And Invasion Of Breast Cancers, Christina S. Pichot

Dissertations & Theses (Open Access)

Cellular invasion represents a critical early step in the metastatic cascade, and many proteins have been identified as part of an “invasive signature.” The non-receptor tyrosine kinase Src is commonly upregulated in breast cancers, often in conjunction with overexpression of EGFR. Signaling from this pathway stimulates cell proliferation, migration, and invasion and frequently involves proteins that regulate the cytoskeleton. My data demonstrates that inhibition of Src, using the small-molecule inhibitor dasatinib, impairs cellular migration and invasion. Furthermore, Src inhibition sensitizes the cells to the effects of the chemotherapeutic doxorubicin resulting in dramatic, synergistic inhibition of proliferation with combination treatments. The …

Osteopontin And Cadherin 11 Are Novel Mediators And Drug Targets For Chronic Lung Diseases, Daniel J. Schneider

Dissertations & Theses (Open Access)

Chronic lung diseases (CLDs) are a considerable source of morbidity and mortality and are thought to arise from dysregulation of normal wound healing processes. An aggressive, feature of many CLDs is pulmonary fibrosis (PF) and is characterized by excess deposition of extracellular matrix (ECM) proteins from myofibroblasts in airways. However, factors regulating myofibroblast biology are incompletely understood. Proteins in the cadherin family contribute epithelial to mesenchymal transition (EMT), a suggested source of myofibroblasts. Cadherin 11 (CDH11) contributes to developmental and pathologic processes that parallel those seen in PF and EMT. Utilizing Cdh11 knockout (Cdh11 -/-) mice, the goal of this …

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 …

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 …

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 …

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 …

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 …

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 …