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- Creators: Barrett, The Honors College
- Creators: Sohn, Sung-Min
- Member of: Theses and Dissertations
- Member of: Barrett, The Honors College Thesis/Creative Project Collection
Description
Mr. Green has stage 4 prostate cancer which has spread to the bones and liver and has become resistant to radiation and standard chemotherapy treatment. After 3 rounds of chemotherapy, his primary oncologist recommends that he participate in a clinical trial. He went to Dr. Red at the Saguaro Clinic after reading on the internet about a new Phase 1 clinical trial that the clinic is hosting, which is designed to target a specific receptor called AB-111 that may be present in malignant prostate, cervical, ovarian, and breast cells. After signing consent and completing the blood screens in the morning at the clinic, Mr. Green is told his liver enzymes are too high and the ranges specified in the protocol prohibit him from enrolling. Mr. Green is noticeably affected and distressed at this news, and Dr. Red recommends end-of-life care. Behind the scenes, this event is noted on official medical documents and trial study rosters as a "screen fail." This narrative, while fictional, is realistic because similar events occur in cancer clinical trial sites on a regular basis. I look at the inner "world" and mental journey of possible clinical trial candidates as they seek out information about clinical trials and gain understanding of their function \u2014 specifically in the context of Phase 1 cancer clinical trials. To whom is the language of the term "screen failure" useful? How does excluding individuals from clinical trials protect their health and does the integrity of the trial data supersede the person's curative goals? What is the message that cancer patients (potential research subjects) receive regarding clinical trials from sources outside their oncologists?
ContributorsMcKane, Alexandra (Author) / Maienschein, Jane (Thesis director) / Ellison, Karin (Committee member) / Foy, Joseph (Committee member) / Barrett, The Honors College (Contributor)
Created2013-12
Description
The purpose of this study, which was done in conjunction with the Arizona Heart Foundation, was to evaluate whether pyridoxine accelerates ulcer wound healing in diabetic patients with ulcers in the lower extremities. In this study, 100 mg of pyridoxine per day was given to patients in the experimental group (while they receive normal wound treatment) while patients in the control group received normal treatment of wounds without the pyridoxine. Over time, wound healing was evaluated by photographing and then measuring the size of patients' ulcer wounds on the photographs. Results from the experimental group were compared with those of the control group to evaluate the efficacy of the pyridoxine treatment. In addition, comparisons of the healing rates were made with respect to whether the patients smoked, had hypertension or hypotension, and the patients' body mass indexes. It has been found that there was no statistically significant difference in the mean healing rates between the control groups and experimental groups. In addition, it has been found that smoking, BMI and blood pressure did not have a statistically appreciable effect on the difference in mean healing rates between the control and experimental groups. This is evidence that pyridoxine did not have a statistically significant effect on wound healing rates.
ContributorsHaupt, Shawn Anthony (Author) / Caplan, Michael (Thesis director) / Pauken, Christine (Committee member) / Pagan, Pedro (Committee member) / Barrett, The Honors College (Contributor) / Harrington Bioengineering Program (Contributor)
Created2013-05
Description
The HIV pandemic spawned a global biomedical research effort which continues today. Because of multinational clinical studies, doctors and health officials possess more tools than ever before for the effective prevention and treatment of HIV/AIDS. The relationship between the United States and Sub-Saharan African nations features prominently within this global research effort. More specifically, many of the most significant HIV-related research findings emanate from clinical trials with a unique multinational configuration: the study protocol is largely designed and funded by American sources but executed at clinical research sites in Sub-Saharan African countries like South Africa and Zimbabwe. This thesis investigates the context and ethics of this configuration, with a focus on US-backed trials conducted in South Africa specifically. Using data collected from semi-structured interviews conducted at South African HIV clinical research sites, this thesis uncovers two significant ethical problems: insufficient benefits delivered to South African clinical trial participants, and informal processes occurring alongside formal protocol. By examining scope, effects, and implications of these problems, it becomes clear that although this research system delivers powerful results, there exists room for improvement.
ContributorsGill, Kohinoor Singh (Author) / Hurlbut, Ben (Thesis director) / Ripley, Charles (Committee member) / Vanig, Thanes (Committee member) / School of Politics and Global Studies (Contributor) / WPC Graduate Programs (Contributor) / Barrett, The Honors College (Contributor)
Created2016-12
Description
The honors thesis presented in this document describes an extension to an electrical engineering capstone project whose scope is to develop the receiver electronics for an RF interrogator. The RF interrogator functions by detecting the change in resonant frequency of (i.e, frequency of maximum backscatter from) a target resulting from an environmental input. The general idea of this honors project was to design three frequency selective surfaces that would act as surrogate backscattering or reflecting targets that each contains a distinct frequency response. Using 3-D electromagnetic simulation software, three surrogate targets exhibiting bandpass frequency responses at distinct frequencies were designed and presented in this thesis.
ContributorsSisk, Ryan Derek (Author) / Aberle, James (Thesis director) / Chakraborty, Partha (Committee member) / Electrical Engineering Program (Contributor, Contributor) / Barrett, The Honors College (Contributor)
Created2021-05
Description
Magnetic resonance spectroscopic imaging (MRSI) is a non-invasive technique that offers a unique ability to provide the spatial distribution of relevant biochemical compounds (metabolites). The ‘spectrum’ of information provided by MRSI is used as biomarkers for the differential diagnosis of several diseases such as cancer or neurological disorders. Treatment responsive brain tumors can appear similar to non-responsive tumors on conventional anatomical MR images, earlier in the therapy, leading to a poor prognosis for many patients. Biomarkers such as lactate are particularly of interest in the oncological studies of solid tumors to determine their energy metabolism, blood flow, and hypoxia. Despite the capability of nearly all clinical MRI scanners to perform MRSI only limited integration of MRSI into routine clinical studies has occurred to date. The major challenges affecting its true potential are the inherently long acquisition time, low signal-to-noise (SNR) of the signals, overlapping of spectral lines, or the presence of artifacts. The goal of this dissertation work is to facilitate MRSI in routine clinical studies without affecting the current patient throughput.
In this work, the Compressed Sensing (CS) strategy was used to accelerate conventional Point RESolved Spectroscopy (PRESS) MRSI by sampling well below the Shannon-Nyquist limit. Two undersampling strategies, namely the pseudo-random variable density and a novel a priori method was developed and implemented on a clinical scanner. Prospectively undersampled MRSI data was acquired from patients with various brain-related concerns. Spatial-spectral post-processing and CS reconstruction pipeline was developed for multi-channel undersampled data. The fidelity of the CS-MRSI method was determined by comparing the CS reconstructed data to the fully sampled data. Statistical results showed that the a priori approach maintained high spectral fidelity compared to the fully sampled reference for an 80% reduction in scan time. Next, an improvement to the CS-MRSI reconstruction was achieved by incorporating coil sensitivity maps as support in the iterative process. Further, a CS-MRSI-based fast lactate spectroscopic imaging method was developed and implemented to achieve complete water and fat suppression for accurate spatial localization and quantification of lactate in tumors. In vitro phantoms were developed, and the sequence was tested to determine the efficacy of CS-MRSI for low SNR signals, the efficacy of the CS acceleration was determined with statistical analysis.
ContributorsBikkamane Jayadev, Nutandev (Author) / Kodibagkar, Vikram (Thesis advisor) / Chang, John (Committee member) / Robison, Ryan (Committee member) / Smith, Barbara (Committee member) / Sohn, Sung-Min (Committee member) / Arizona State University (Publisher)
Created2021
Description
The purpose of this investigation is to apply a machine learning algorithm with de-identified, historic oncology clinical trial data to assess the theoretical understanding of predictive modeling to derive potential clinical practice recommendations. Within this study, electronic medical records from the HonorHealth Virginia G. Piper Institute will undergo data visualization to identify potential correlations and trends critical for model creation as well as further identify potential expansions or limitations of scope regarding model purpose. Hypothesis pursued post data visualization was the development of a predictive model for 6-month survival. Current standard is estimated physician accuracy at 56.5% accuracy at 6 months out. This study created supervised learning models using decision trees, KNN, SVM and Ensemble methods using combinations of LASSO Logistic Regression and Know-GRFF Random Forest for feature selection. SVM trained on a combined set of LASSO and Know-GRRF featured produced the highest performing model at 75.5% with an AUC of 0.82. This study demonstrates the potential for applying predictive modeling on readily available EMR records to drive clinical practice recommendations. The models developed could potentially, with further development, be used as an ancillary tool for jumpstarting patient-physician conversations on survival and life expectancy.
ContributorsLi, Richard Longfei (Co-author) / Liu, Li (Co-author, Thesis director) / Gosselin, Kevin (Co-author, Committee member) / Harrington Bioengineering Program (Contributor, Contributor) / Barrett, The Honors College (Contributor)
Created2019-05
Description
Animal testing is a long-running institution in biomedical research that is seen as a necessary step in the development of new drugs and treatments in the United States. Using animal models that have biological similarities to humans, it is assumed that we can ethically perform basic research that is translatable to human health. However, recent years have seen this assumption challenged by the fact that most preclinical research fails to survive the gauntlet of human trials into a functioning treatment on the market. This has marked ethical implications for both the people that depend on new treatments for their health, and the animals used in the research themselves. The purpose of this thesis is to develop solutions for the problems facing animal testing in the United States. First, I identify the political and economic basis of the modern system of animal testing by examining legislation and the IACUCs that govern animal research to understand why the practice continues to be used despite its low rate of success. I then examine factors such as epigenetics and the laboratory environment to explain reasons why animal research fails to translate to humans. Finally, I cover new in-vitro methods such as organoids and organ-on-a-chip technologies to show the potential that alternatives hold for biomedical research. As a result of this analysis, I propose the further integration of alternatives into our system of animal testing to make up for the translational failures the field currently experiences. I also highlight the importance of having IACUCs balanced between animal researchers and members of the public to improve the welfare of animals used in research and increase the transparency of their work. Including more animals into the Animal Welfare Act is also proposed to better standardize our treatment of them and keep experimental results more consistent.
ContributorsCammann, Davis Bukovi (Author) / Barca, Lisa (Thesis director) / Hurlbut, Ben (Committee member) / Sterner, Beckett (Committee member) / School of Life Sciences (Contributor, Contributor) / Barrett, The Honors College (Contributor)
Created2020-12
Description
The ability of magnetic resonance imaging (MRI) to image any part of the human body without the effects of harmful radiation such as in CAT and PET scans established MRI as a clinical mainstay for a variety of different ailments and maladies. Short wavelengths accompany the high frequencies present in high-field MRI, and are on the same scale as the human body at a static magnetic field strength of 3 T (128 MHz). As a result of these shorter wavelengths, standing wave effects are produced in the MR bore where the patient is located. These standing waves generate bright and dark spots in the resulting MR image, which correspond to irregular regions of high and low clarity. Coil loading is also an inevitable byproduct of subject positioning inside the bore, which decreases the signal that the region of interest (ROI) receives for the same input power. Several remedies have been proposed in the literature to remedy the standing wave effect, including the placement of high permittivity dielectric pads (HPDPs) near the ROI. Despite the success of HPDPs at smoothing out image brightness, these pads are traditionally bulky and take up a large spatial volume inside the already small MR bore. In recent years, artificial periodic structures known as metamaterials have been designed to exhibit specific electromagnetic effects when placed inside the bore. Although typically thinner than HPDPs, many metamaterials in the literature are rigid and cannot conform to the shape of the patient, and some are still too bulky for practical use in clinical settings. The well-known antenna engineering concept of fractalization, or the introduction of self-similar patterns, may be introduced to the metamaterial to display a specific resonance curve as well as increase the metamaterial’s intrinsic capacitance. Proposed in this paper is a flexible fractal-inspired metamaterial for application in 3 T MR head imaging. To demonstrate the advantages of this flexibility, two different metamaterial configurations are compared to determine which produces a higher localized signal-to-noise ratio (SNR) and average signal measured in the image: in the first configuration, the metamaterial is kept rigid underneath a human head phantom to represent metamaterials in the literature (single-sided placement); and in the second, the metamaterial is wrapped around the phantom to utilize its flexibility (double-sided placement). The double-sided metamaterial setup was found to produce an increase in normalized SNR of over 5% increase in five of six chosen ROIs when compared to no metamaterial use and showed a 10.14% increase in the total average signal compared to the single-sided configuration.
ContributorsSokol, Samantha (Author) / Sohn, Sung-Min (Thesis director) / Allee, David (Committee member) / Jones, Anne (Committee member) / Barrett, The Honors College (Contributor) / Electrical Engineering Program (Contributor)
Created2022-05