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Diabetes is a disease characterized by reduced insulin action and secretion, leading to elevated blood glucose. In the 1990s, studies showed that intravenous injection of fatty acids led to a sharp negative response in insulin action that subsided hours after the injection. The molecule associated with diminished insulin signalling response

Diabetes is a disease characterized by reduced insulin action and secretion, leading to elevated blood glucose. In the 1990s, studies showed that intravenous injection of fatty acids led to a sharp negative response in insulin action that subsided hours after the injection. The molecule associated with diminished insulin signalling response was a byproduct of fatty acids, diacylglycerol. This dissertation is focused on the formulation of a model built around the known mechanisms of glucose and fatty acid storage and metabolism within myocytes, as well as downstream effects of diacylglycerol on insulin action. Data from euglycemic-hyperinsulinemic clamp with fatty acid infusion studies are used to validate the qualitative behavior of the model and estimate parameters. The model closely matches clinical data and suggests a new metric to determine quantitative measurements of insulin action downregulation. Analysis and numerical simulation of the long term, piecewise smooth system of ordinary differential equations demonstrates a discontinuous bifurcation implicating nutrient excess as a driver of muscular insulin resistance.
ContributorsBurkow, Daniel Harrison (Author) / Li, Jiaxu (Thesis advisor) / Castillo-Chavez, Carlos (Thesis advisor) / Kuang, Yang (Committee member) / Holechek, Susan (Committee member) / Arizona State University (Publisher)
Created2017
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In the United States, 12% of women are typically diagnosed with breast cancer, where 20-30% of these cases are identified as Triple Negative Breast Cancer (TNBC). In the state of Arizona, 810 deaths occur due to breast cancer and more than 4,600 cases are diagnosed every year (American Cancer Society). The lack

In the United States, 12% of women are typically diagnosed with breast cancer, where 20-30% of these cases are identified as Triple Negative Breast Cancer (TNBC). In the state of Arizona, 810 deaths occur due to breast cancer and more than 4,600 cases are diagnosed every year (American Cancer Society). The lack of estrogen, progesterone, and HER2 receptors in TNBC makes discovery of targeted therapies further challenging. To tackle this issue, a novel multi-component drug vehicle is presented. Previously, we have shown that mitoxantrone, a DNA damaging drug, can sensitize TNBC cells to TRAIL, which is a protein that can selectively kill cancer cells. In this current study, we have formulated aminoglycoside-derived nanoparticles (liposomes) loaded with mitoxantrone, PARP inhibitors, for delivery to cancer cells. PARP inhibitors are helpful in preventing cancer cells from repairing their DNA following damage with other drugs (e.g. mitoxantrone). Various treatment liposome groups, consisting of lipid-containing polymers (lipopolymers) synthesized in our laboratory, were formulated and characterized for their size, surface charge, and stability. PARP inhibitors and treatment of cells for in-vitro and in-vivo experiments with these liposomes resulted in synergistic death of cancer cells. Finally, studies to evaluate the pre-clinical efficacy of these approaches using immuno-deficient mouse models of TNBC disease have been initiated.
ContributorsMuralikrishnan, Harini (Author) / Rege, Kaushal (Thesis advisor) / Holechek, Susan (Committee member) / Nannenga, Brent (Committee member) / Arizona State University (Publisher)
Created2018
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Description
Memory CD8+ T-cells can persist in the absence of antigen, primed for immediate activation and proliferation if later exposed to the same antigen. These cytotoxic lymphocytes provide long-term immunity following an acute infection. Studies have observed that intermediate levels of general T cell transfer prior to infection may cause an

Memory CD8+ T-cells can persist in the absence of antigen, primed for immediate activation and proliferation if later exposed to the same antigen. These cytotoxic lymphocytes provide long-term immunity following an acute infection. Studies have observed that intermediate levels of general T cell transfer prior to infection may cause an inappropriate response resulting in increased pathology rather than prevention. Therefore, our study focused on a memory CD8 T-cell therapy using lymphocytic choriomeningitis virus (LCMV) specific splenocytes, which activate and proliferate at an accelerated pace compared to that of naive T-cells. LCMV is a natural murine pathogen which also poses a zoonotic infection threat to humans, and the effect of immune cell vaccination therapies for LCMV is not fully understood. We observed the effect of multiple memory CD8 T cell dosage levels on overall disease and memory CD8 T-cell response to the virus. Infection by exposure to a carrier was shown to have a reduced impact on mice receiving higher doses of memory T cells prior to infection compared to mice receiving less or no memory cells. Higher presence of activated memory cells were shown to correlate with less disease-related weight loss and accelerated recovery times. Survival rate after exposure to carriers was not shown to be affected by dosage level, warranting further research regarding the prevalence of the immunopathology observed in other studies in natural murine transmission models.
ContributorsMiller, Charles (Author) / Blattman, Joseph (Thesis director) / Holechek, Susan (Committee member) / Carmen, Joshua (Committee member) / W. P. Carey School of Business (Contributor) / School of Life Sciences (Contributor) / Barrett, The Honors College (Contributor)
Created2016-05
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Description
Among wild rodent populations, vertical transmission is believed to constitute the primary route of infection for Lymphocytic Choriomeningitis Virus (LCMV), a non-lytic arenavirus with both acute and chronic forms. When carrier mice infected at birth with the acute Armstrong strain reproduce, they generate congenital carrier offspring containing a quasispecies of

Among wild rodent populations, vertical transmission is believed to constitute the primary route of infection for Lymphocytic Choriomeningitis Virus (LCMV), a non-lytic arenavirus with both acute and chronic forms. When carrier mice infected at birth with the acute Armstrong strain reproduce, they generate congenital carrier offspring containing a quasispecies of LCMV that includes Armstrong as well as its chronic Clone-13 variant. This study examined the genetic trends in the vertical transmission of LCMV from mothers infected perinatally with Clone-13. Viral isolates obtained from the serum of congenital carrier offspring were partially sequenced to reveal residue 260 in the glycoprotein-encoding region of their S segment, the site of a major amino acid change differentiating the chronic and acute strains. It was found that the phenylalanine-to-leucine mutation associated with Clone-13 was present in 100% of the isolates, strongly indicating that the offspring of Clone-13 carriers contain exclusively the chronic variant. This research has broad implications for the epidemiology of the virus, and, given the predominance of Armstrong in the wild, suggests that there must be a biological cost associated with Clone-13 infection in non-carriers.
ContributorsFrear, Cody Christian (Author) / Blattman, Joseph (Thesis director) / Hogue, Brenda (Committee member) / Holechek, Susan (Committee member) / Barrett, The Honors College (Contributor) / School of Human Evolution and Social Change (Contributor) / School of Life Sciences (Contributor)
Created2015-05
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Description
Stroke is a devastating disease that affects thousands of individuals each year. Stroke, specifically cerebral ischemia, and immune responses are important areas of study and focus. Previous studies on stroke in mouse models had shown the upregulation of a specific micro-RNA: miR-1224. We hypothesized that miR-1224 was responsible for the

Stroke is a devastating disease that affects thousands of individuals each year. Stroke, specifically cerebral ischemia, and immune responses are important areas of study and focus. Previous studies on stroke in mouse models had shown the upregulation of a specific micro-RNA: miR-1224. We hypothesized that miR-1224 was responsible for the regulation of the ST2 receptor protein’s expression. We performed cellular transfection on murine splenocytes with four different miRNAs—miR-1224-mimic, miR-1224-inhibitor, miR-451-mimic, and a control. We predicted that transfection with 1224m would decrease ST2 expression, while transfection with 1224i would increase ST2 expression. Two complete trials were run, and analysis of the results included RT-PCR of both miRNA samples and mRNA samples to confirm transfection and controlled transcription. Reverse transcription and qPCR of miRNA was done in order to confirm that transfection was in fact successful. Reverse transcription and qPCR of the mRNA was done in order to confirm that ST2 mRNA was not altered; this allowed us to attribute any changes in ST2 protein levels to miRNA interactions, as the mRNA levels were consistent. Western blotting was done in order to assess relative protein content. We found that transfection with 1224m slightly decreased ST2 expression and transfection with 1224i slightly increased ST2 expression, however, after assessing the p-values through statistical analyses, neither difference was significant. As such, our hypothesis was rejected as it is not evident that miR-1224 plays a significant role on ST2 gene expression. Future studies are needed in order to analyze alternate protein targets to fully assess the role of miR-1224.
ContributorsReddy, Nihaal (Author) / Holechek, Susan (Thesis director) / Ahmad, Saif (Committee member) / Wood, Kristofer (Committee member) / School of Human Evolution and Social Change (Contributor) / School of Life Sciences (Contributor) / Barrett, The Honors College (Contributor)
Created2018-05
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Description
Pathogens such as lymphocytic choriomeningitis virus (LCMV) cause abnormalities in the nervous system of developing mice and humans. While humans are able to recover from infection and clear the virus, the mouse immune system tolerates the virus and lifelong infection ensues. In order to understand the factors driving LCMV evolution

Pathogens such as lymphocytic choriomeningitis virus (LCMV) cause abnormalities in the nervous system of developing mice and humans. While humans are able to recover from infection and clear the virus, the mouse immune system tolerates the virus and lifelong infection ensues. In order to understand the factors driving LCMV evolution and evaluate its neuropathogenesis, a mouse model was needed. To establish congenital infection, newborn C57BL/6J mice were intra-cerebrally (i.c.) injected with 1 x 103 PFU LCMV Armstrong. Mice failed to thrive, resulting in a linear reduction in survival over the following two weeks and overall survival of 13%. Surviving mice did not have virus in their circulation after thirty days. As an alternative, 500 PFU of LCMV Armstrong was injected intraperitoneally (i.p.) into other litters. While this was associated with significantly reduced mortality, no mice in this group developed persistent infection either. ELISAs revealed that the mothers of injected pups developed a robust humoral response, confirming earlier reports that contact-associated acute infection occurs (Hotchin, 1971). In addition, the offspring of two litters of mice (out of six tested) also had antibodies to the virus, but at slightly lower titers. This indicates that the humoral response of the mothers may play a role in the neonatal clearance of infection. A higher titer of LCMV in i.p. injections may be necessary to overcome these barriers and establish chronic infection. In contrast, a lower dose of LCMV is recommended for i.c. injections, as the mortality seemed directly linked to the effects of the virus on offspring growth and development. Exposure to the virus in utero may also be necessary to increase survival and the likelihood of chronic infection.
ContributorsMorrow, Kristen Nicole (Author) / Blattman, Joseph (Thesis director) / Holechek, Susan (Committee member) / Franco, Lina (Committee member) / School of Life Sciences (Contributor) / Barrett, The Honors College (Contributor)
Created2016-05
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Description
Within our current educational infrastructure, there’s a lack of substantial preventive care knowledge present among elementary schoolchildren. With education cuts occurring statewide, many schools are left impoverished and schools are incapable of implementing various programs to benefit their local communities. This endeavor aims to visit public and charter elementary schools

Within our current educational infrastructure, there’s a lack of substantial preventive care knowledge present among elementary schoolchildren. With education cuts occurring statewide, many schools are left impoverished and schools are incapable of implementing various programs to benefit their local communities. This endeavor aims to visit public and charter elementary schools in the Phoenix Valley to educate youth regarding easily avoidable health risks by implementing healthy eating habits and exercise. Project BandAid will immerse students ages 7-9 in hands-on activities to enhance their knowledge on hygiene, healthy eating habits, and safety. This project incorporated funding from the Woodside Community Action Grant and Barrett, the Honors College as well as the help from Alpha Epsilon Delta (AED) volunteers.
ContributorsCovarrubias, Sidney Alicia (Co-author) / Kothari, Karishma (Co-author) / John, Benson (Co-author) / Fette, Donald (Thesis director) / Holechek, Susan (Committee member) / Sanford School of Social and Family Dynamics (Contributor) / School of Molecular Sciences (Contributor) / School for the Future of Innovation in Society (Contributor) / Barrett, The Honors College (Contributor)
Created2019-05