Medicine and Health Sciences Commons^™

Towards A Structural Understanding Of Spore Germination In Clostridium Difficile, Chloe M. Adams

Graduate College Dissertations and Theses

Clostridium difficile is a Gram-positive bacterium that causes a toxin-mediated disease, typically in individuals whose normal intestinal flora has been compromised by antibiotic therapy. C. difficile is naturally resistant to many antibiotics and produces spores that can withstand harsh environmental conditions and many disinfectants, making the infection difficult to clear and easy to spread. The infection begins when spores from the environment are ingested and germinate upon exposure to taurocholate and glycine in the digestive tract. This germination process is required to initiate infection and thus represents a good target for the development of novel therapeutics. Although spore germination is …

Glycogen Synthase Kinase-3Β: An Investigation Of The Novel Serine 389 Phosphorylation Site, Brendan Deegan Hare

Graduate College Dissertations and Theses

Stress associated psychiatric disorders such as depression, anxiety, and post-traumatic stress disorder affect a large proportion of the population. Reductions in the complexity of neuronal morphology and reduced neurogenesis are commonly observed outcomes following stress exposure in rodent models and may represent a mechanism for the reduced brain volume in stress sensitive regions such as the hippocampus observed in individuals diagnosed with stress associated disorders. Multiple lines of evidence suggest that glycogen synthase kinase (GSK)-B may play a role in the neurodegenerative phenotype observed following stress exposure. GSK3B is atypical in that it is inhibited by phosphorylation. This inhibitory phosphorylation …

Reverse Engineering The Human Brain: An Evolutionary Computation Approach To The Analysis Of Fmri, Nicholas Allgaier

Graduate College Dissertations and Theses

The field of neuroimaging has truly become data rich, and as such, novel analytical methods capable of gleaning meaningful information from large stores of imaging data are in high demand. Those methods that might also be applicable on the level of individual subjects, and thus potentially useful clinically, are of special interest. In this dissertation we introduce just such a method, called nonlinear functional mapping (NFM), and demonstrate its application in the analysis of resting state fMRI (functional Magnetic Resonance Imaging) from a 242-subject subset of the IMAGEN project, a European study of risk-taking behavior in adolescents that includes longitudinal …

Inhibitory Control Efficiency In Successful Weight Loss Participants, Kathryn Curran Olds

Graduate College Dissertations and Theses

Eating unhealthy foods and eating past satiety are inappropriate behaviors that promote obesity. The ability to effectively inhibit an inappropriate behavior is a key component of cognitive restraint and its impairment has been previously linked to obesity. In this study, a Go/No-Go fMRI task was completed by a cohort of adult women that had experienced initial weight loss followed by various levels of weight regain or continued weight loss. Region of interest fMRI analysis revealed that greater total weight loss was significantly related to decreasing activation in the right inferior frontal gyrus and the right superior frontal gyrus. These results …

Longitudinal Extension Of Primary Afferents Is Regulated By Spingosine 1-Phosphate Receptors And Tyrosine Kinase Receptor B In The Embryonic Spinal Cord Via A Brain Derived Neurotrophic Factor Related Mechanism, Michelle Mcnamara

Graduate College Dissertations and Theses

Primary sensory afferent outgrowth within the developing longitudinal pathway of the spinal cord is important for intrasegmental and intersegmental communication that underlies coordination and development of reflexes and contributes to sensory perception. The endogenous mechanisms that regulate primary sensory afferent extension are the primary focus of this dissertation.

This dissertation tested the hypothesis that primary sensory afferent extension in the longitudinal pathway is regulated by sphingosine 1-phosphate type 1 receptor (S1P1R) and tyrosine kinase receptor B (TrkB) through a brain derived neurotrophic factor (BDNF) related mechanism. To test this hypothesis we used embryonic day five (E5) chicken embryos, as this …

Ubiquitin Ligase Trim32 And Chloride-Sensitive Wnk1 As Regulators Of Potassium Channels In The Brain, Eugene Miler Cilento

Graduate College Dissertations and Theses

The voltage-gated potassium channel Kv1.2 impacts membrane potential and therefore excitability of neurons. Expression of Kv1.2 at the plasma membrane (PM) is critical for channel function, and altering Kv1.2 at the PM is one way to affect membrane excitability. Such is the case in the cerebellum, a portion of the brain with dense Kv1.2 expression, where modulation of Kv1.2 at the PM can impact electrical activity of neurons and ultimately cerebellum-dependent learning. Modulation of Kv1.2 at the PM can occur through endocytic trafficking of the channel; however mechanisms behind this process in the brain remain to be defined.

The goal …

Traumatic Brain Injury Causes Endothelial Dysfunction In Mesenteric Arteries 24 Hrs After Injury, Ivette Ariela Nunez

Graduate College Dissertations and Theses

Traumatic brain injury (TBI) is the most frequent cause of death in children and young adults in the United States. Besides emergency neurosurgical procedures, there are few medical treatment options to improve recovery in people who have experienced a TBI. Management of patients who survive TBI is complicated by both central nervous system and peripheral systemic effects. The pathophysiology of systemic inflammation and coagulopathy following TBI has been attributed to trauma-induced endothelial cell dysfunction; however, there is little knowledge of the mechanisms by which trauma might impact the functions of the vascular endothelium at sites remote from the injury. The …

Transient Ischemic Attack (Tia) Guideline Knowledge And Perceived Barriers To Implementation Amongst Emergency Department Health Care Providers In A Rural State, Christopher T. Ingvoldstad

Graduate College Dissertations and Theses

Transient Ischemic Attack (TIA) is a prominent risk factor for subsequent stroke, and its associated morbidity, mortality, and health care costs. Studies have demonstrated up to 80% reductions in subsequent stroke rate with prompt, optimized protocols for rapid TIA evaluation and treatment. National Stroke Association (NSA) and American Heart Association (AHA) guidelines have recommended institution of protocols assuring timely completion of the recommended testing, and evaluation by a stroke expert within 48 hours. However, limited literature exists on the implementation of guideline-based care in rural regions, and the few studies related to TIA suggest that barriers including difficulty accessing services …

Mechanisms Of Seizure During Pregnancy And Preeclampsia, Abbie Chapman Johnson

Graduate College Dissertations and Theses

Eclampsia is defined as de novo seizure in a woman with the hypertensive complication of pregnancy known as preeclampsia (PE), and is a leading cause of maternal and fetal morbidity and mortality worldwide. The pathogenesis of eclamptic seizure remains unknown, but is considered a form of hypertensive encephalopathy where an acute rise in blood pressure causes loss of cerebral blood flow (CBF) autoregulation and hyperperfusion of the brain that results in vasogenic edema formation and subsequent seizure. However, eclamptic seizure can occur during seemingly uncomplicated pregnancies, in the absence of hypertension and PE, suggesting that normal pregnancy may predispose the …