Matching Items (88)
Description
An introduction to neuroscientific thought aimed at an audience that is not educated in biology. Meant to be readable and easily understood by anyone with a high school education. The first section is completed in its entirety, with outlines for the proposed final sections to be completed over the next few years.
ContributorsNelson, Nicholas Alan (Author) / Olive, M. Foster (Thesis director) / Brewer, Gene (Committee member) / Barrett, The Honors College (Contributor) / Department of Psychology (Contributor) / School of Life Sciences (Contributor) / School of Historical, Philosophical and Religious Studies (Contributor)
Created2014-05
ContributorsChandler, N. Kayla (Author) / Neisewander, Janet (Thesis director) / Sanabria, Federico (Committee member) / Olive, M. Foster (Committee member) / Barrett, The Honors College (Contributor) / College of Liberal Arts and Sciences (Contributor)
Created2013-05
Description
In this thesis, glycan nodes, the basic subunits of complex biological sugars, were studied to determine the reproducibility of gas chromatography-mass spectrometry (GC/MS) based methylation analysis of whole blood plasma by normalization using an internal standard of heavy permethylated glycans. Glycans are complex biological sugars that have a variety of applications in the human body and will display aberrant compositions when produced by cancerous cells. Thus an assay to determine their composition can be used as a diagnostic tool. It was shown that the assay may have potential use, but needs further refinement to become an improvement over current methods by analyzing the results of ratio-determination and replicate experiments.
ContributorsMiyasaki, Tyler Takeo (Author) / Borges, Chad (Thesis director) / Van Horn, Wade (Committee member) / Barrett, The Honors College (Contributor) / Department of Chemistry and Biochemistry (Contributor) / Chemical Engineering Program (Contributor)
Created2015-05
Description
Western diets, high in dietary fat and red meat, are associated with hyperglycemia and weight gain, symptoms that promote insulin resistance and diabetes. Previous studies have shown that elevated glucose promotes glycation of circulating proteins such as albumin, which is thought to lead to hyperglycemia complications. It was hypothesized that diets with no meat consumption (pesco-vegetarian and lacto-vegetarian) would reduce protein glycation, in comparison to a diet with meat. Forty six healthy adult omnivorous subjects were randomized into one of three groups and instructed to either consume red meat (i.e. meat) or poultry twice per day (control), eliminate meat and increase fish consumption (pesco-vegetarian), or adopt a vegetarian diet devoid of fish, meat or poultry (lacto-vegetarian) for four weeks. Fasting plasma samples were collected from participants at baseline and after 4 weeks of the dietary intervention. Plasma glucose concentrations were measured using a commercially available kit. Percent glycated albumin was measured on a separate aliquot of plasma by mass spectrometry. Plasma glucose concentrations were significantly increased following 4-weeks of pesco-vegetarian diet (P=0.002, paired t-test). Neither the lacto-vegetarian (P=0.898) or the control diet (P=0.233) affected plasma glucose concentrations. Despite the significant increase in plasma glucose following a pesco-vegetarian diet, no change in percent glycated albumin was observed (P>0.50, ANOVA). These findings may indicate a protective effect of the pesco-vegetarian diet on protein glycation in the presence of elevated plasma glucose and suggest the need for additional studies to examine the link between increased fish consumption and glucose regulation.
ContributorsRaad, Noor (Author) / Sweazea, Karen (Thesis director, Committee member) / Borges, Chad (Committee member) / Barrett, The Honors College (Contributor) / School of Life Sciences (Contributor)
Created2015-05
Description
Dielectrophoresis is a separations strategy that has the potential to separate small amounts of different proteins from each other. The forces at play in the channel used for dielectrophoresis are electroosmotic flow (EOF), electrophoresis (EP), and dielectrophoresis (DEP). EOF is the force exerted on liquid from an applied potential (1). EP is the force exerted on charged particles in a uniform electric field (2). DEP is the force exerted on particles (charged and uncharged) in a non-uniform electric field (3). This experiment was focused on the testing of a new microfluidic device to see if it could improve the focusing of proteins in dielectrophoresis. It was predicted that the addition of a salt bridge would improve focusing by preventing the ions created by the electrolysis of water around the electrodes from interacting with the proteins and causing aggregation, among other problems. Control trials using the old device showed that electrolysis was likely occurring and was the causal agent for poor outcomes. After applying the electric potential for some time a pH front traveled through the channel causing aggregation of proteins and the current in the channel decreased rapidly, even while the voltage was held constant. The resistance in the channels of the control trials also slightly decreased over time, until the pH shift occurred, at which time it increased rapidly. Experimental trials with a new device that included salt bridges eliminated this pH front and had a roughly linear increase of current in the channel with the voltage applied. This device can now be used in future research with protein dielectrophoresis, including in the potential differentiation of different proteins. References: 1) Electroosmosis. Oxford Dictionary of Biochemistry and Molecular Biology. 2. Oxford University Press: Oxford, England. 2006. 2) Electrophoresis. Oxford Dictionary of Biochemistry and Molecular Biology. 2. Oxford University Press: Oxford, England. 2006. 3) Dielectrophoresis. Oxford Dictionary of Biochemistry and Molecular Biology. 2. Oxford University Press: Oxford, England. 2006.
ContributorsHayes, Katelyn Donna (Author) / Hayes, Mark (Thesis director) / Borges, Chad (Committee member) / School of Life Sciences (Contributor) / Department of Psychology (Contributor) / Barrett, The Honors College (Contributor)
Created2016-05
Description
Major Depressive Disorder (MDD) affects over 300 million people worldwide, with the hippocampus showing decreased volume and activity in patients with MDD. The current study investigated whether a novel preclinical model of depression, unpredictable intermittent restraint (UIR), would decrease hippocampal neuronal dendritic complexity. Adult Sprague Dawley rats (24 male, 24 female) were equally divided into 4 groups: control males (CON-M), UIR males (UIR-M), control females (CON-F) and UIR females (UIR-F). UIR groups received restraint and shaking on an orbital shaker on a randomized schedule for 30 or 60 minutes/day for two to six days in a row for 26 days (21 total UIR days) before behavioral testing commenced. UIR continued and was interspersed between behavioral test days. At the end of behavioral testing, brains were processed. The behavior is published and not part of my honor’s thesis; my contribution involved quantifying and analyzing neurons in the hippocampus. Several neuronal types are found in the CA3 subregion of the hippocampus and I focused on short shaft (SS) neurons, which show different sensitivities to stress than the more common long shaft (LS) variety. Brains sections were mounted to slides and Golgi stained. SS neurons were drawn using a microscope with camera lucida attachment and quantified using the number of bifurcations and dendritic intersections as metrics for dendritic complexity in the apical and basal areas separately. The hypothesis that SS neurons in the CA3 region of the hippocampus would exhibit apical dendritic simplification in both sexes after UIR was not supported by our findings. In contrast, following UIR, SS apical dendrites were more complex in both sexes compared to controls. Although unexpected, we believe that the UIR paradigm was an effective stressor, robust enough to illicit neuronal adaptations. It appears that the time from the end of UIR to when the brain tissue was collected, or the post-stress recovery period, and/or repeated behavioral testing may have played a role in the observed increased neuronal complexity. Future studies are needed to parse out these potential effects.
ContributorsAcuna, Amanda Marie (Author) / Conrad, Cheryl (Thesis director) / Corbin, William (Committee member) / Olive, M. Foster (Committee member) / School of Life Sciences (Contributor) / Department of Psychology (Contributor) / Barrett, The Honors College (Contributor)
Created2020-12
Description
Viral protein U (Vpu) is a type-III integral membrane protein encoded by Human Immunodeficiency Virus-1 (HIV- 1). It is expressed in infected host cells and plays several roles in viral progeny escape from infected cells, including down-regulation of CD4 receptors. But key structure/function questions remain regarding the mechanisms by which the Vpu protein contributes to HIV-1 pathogenesis. Here we describe expression of Vpu in bacteria, its purification and characterization. We report the successful expression of PelB-Vpu in Escherichia coli using the leader peptide pectate lyase B (PelB) from Erwinia carotovora. The protein was detergent extractable and could be isolated in a very pure form. We demonstrate that the PelB signal peptide successfully targets Vpu to the cell membranes and inserts it as a type I membrane protein. PelB-Vpu was biophysically characterized by circular dichroism and dynamic light scattering experiments and was shown to be an excellent candidate for elucidating structural models.
ContributorsDeb, Arpan (Author) / Johnson, William (Author) / Kline, Alexander (Author) / Scott, Boston (Author) / Meador, Lydia (Author) / Srinivas, Dustin (Author) / Martin Garcia, Jose Manuel (Author) / Dorner, Katerina (Author) / Borges, Chad (Author) / Misra, Rajeev (Author) / Hogue, Brenda (Author) / Fromme, Petra (Author) / Mor, Tsafrir (Author) / ASU Biodesign Center Immunotherapy, Vaccines and Virotherapy (Contributor) / College of Liberal Arts and Sciences (Contributor) / School of Life Sciences (Contributor) / Biodesign Institute (Contributor) / School of Molecular Sciences (Contributor) / Applied Structural Discovery (Contributor) / Personalized Diagnostics (Contributor)
Created2017-02-22
Description
Major Depressive Disorder (MDD) is a widespread mood disorder that affects more than 300 million people worldwide and yet, high relapse rates persist. This current study aimed to use an animal model for depression, unpredictable intermittent restraint (UIR), to investigate changes in a subset of neurons within the hippocampus, a region of high susceptibility in MDD. Adult male and female Sprague-Dawley rats were randomly assigned to four treatment groups based on sex (n = 48, n = 12/group). Half of the rats underwent UIR that involved restraint with orbital shaking (30 min or 1 h) for 2-6 consecutive days, followed by one or two days of no stressors; the other half of the rats were undisturbed (CON). UIR rats were stressed for 28 days (21 days of actual stressors) before behavioral testing began with UIR continuing between testing days for nearly 70 days. Rats were then euthanized between 9 and 11 days after the last UIR session. Brains were processed for Golgi stain and long-shaft (LS) neurons within the hippocampal CA3a and CA3b regions were quantified for dendritic complexity using a Camera Lucida attachment. Our findings failed to support our hypothesis that UIR would produce apical dendritic retraction in CA3 hippocampal LS neurons in both males and females. Given that UIR failed to produce CA3 apical dendritic retraction in males, which is commonly observed in the literature, we discuss several reasons for these findings including, time from the end of UIR to when brains were sampled, and the effects of repeated cognitive testing. Given our published findings that UIR impaired spatial ability in males, but not females, we believe that UIR holds validity as a chronic stress paradigm, as UIR attenuated body weight gain in both males and females and produced reductions in thymus gland weight in UIR males. These findings corroborate UIR as an effective stressor in males and warrant further research into the timing of UIR-induced changes in hippocampal CA3 apical dendritic morphology.
ContributorsReynolds, Cindy Marie (Author) / Conrad, Cheryl D. (Thesis director) / Olive, M. Foster (Committee member) / School of Molecular Sciences (Contributor) / Department of English (Contributor) / Barrett, The Honors College (Contributor)
Created2020-12
Description
The rise in community-associated methicillin-resistant Staphylococcus aureus (MRSA) infections and the ability of the organism to develop resistance to antibiotics necessitate new treatment methods for MRSA. Geopolymers (GPs) are cheap, porous materials that have demonstrated adsorptive capabilities. In this study, GPs were investigated for their ability to adsorb whole MRSA cells and MRSA secreted proteins [culture filtrate proteins (CFPs)] as a complementary method of controlling MRSA infections. GPs have been synthesized with variable pore sizes (meso/macro scale) and further modified with stearic acid (SA) to increase surface hydrophobicity. Four GPs (SA-macroGP, macroGP, SA-mesoGP, and mesoGP) were incubated with whole cells and with CFPs to quantify GP adsorption capabilities. Following MRSA culture incubation with GPs, unbound MRSA cells were filtered and plated to determine cell counts. Following CFP incubation with GPs, unbound CFPs were separated via SDS-PAGE, stained with SYPRO Ruby, and analyzed using densitometry. Results indicate that macroGP was the most effective at adsorbing whole MRSA cells. Visual banding patterns and densitometry quantitation indicate that SA-mesoGP was the most effective at adsorbing CFP. Ultimately, GP-based products may be further developed as nonselective or selective adsorbents and integrated into fibrous materials for topical applications.
ContributorsGanser, Collin (Co-author, Co-author) / Haydel, Shelley E. (Thesis director) / Seo, Don (Committee member) / Borges, Chad (Committee member) / School of Earth and Space Exploration (Contributor) / School of Life Sciences (Contributor) / Barrett, The Honors College (Contributor)
Created2020-05
Description
The purpose of this thesis creative project was to create an educational video to present research findings on the increasingly important issue of human biospecimen preanalytic variables. When a human biospecimen, such as blood, urine, or tissue, is removed from the body, it is subjected to a plethora of variables that are not recorded or regulated in a vast majority of cases. Frequently, these samples arrive at the research or pathology lab with an unknown history, then undergo analysis for translational research purposes, or to guide clinical management decisions. Thus, compromised specimen quality caused by preanalytic variables has substantial, and potentially devastating, downstream effects. To identify the preanalytic variables with the greatest impact on blood and tissue specimen quality, 45 articles were gathered using PubMed and Google Scholar databases and cited. Based on the articles, the top five variables with the most detrimental effects were identified for both blood and tissue samples. Multiple sets of parameters ensuring specimen fitness were compared for each of the five variables for each specimen type. Then, specific parameters guaranteeing the fitness of the greatest number of analytes were verified. To present the research findings in greater detail, a paper was written that focused on identifying the top variables and key parameters to ensure analyte fitness. To present the overall issue in an easy-to-digest format, a storyboard and script were created as a guideline for a final video project. Ultimately, two alternate versions of the video were created to pertain to the audience of choice (one version for patients, one version for professionals). It is the hope that these videos will be used as educational tools to continue efforts to standardize and enforce human biospecimen preanalytic variable parameters. This is a necessary step to improve the accuracy of our biomedical research data and the healthcare of patients worldwide.
ContributorsAzcarate, Heather (Author) / Compton, Carolyn (Thesis director) / LaBaer, Joshua (Committee member) / Borges, Chad (Committee member) / Barrett, The Honors College (Contributor) / Department of Psychology (Contributor)
Created2018-12