Honors Theses
Permanent URI for this collectionhttps://hdl.handle.net/10217/239621
Browse
Recent Submissions
Item Open Access Hypoxia-inducible factor-1α signaling in cardiac adaptations to hypobaric hypoxia(Colorado State University. Libraries, 2024) Johnson, Anna C., authorPrevious data from the Chicco lab demonstrated that skeletal muscle metabolic adaptations to hypobaric hypoxia (HH) involves glucocorticoid receptor (GR) signaling, but not hypoxia inducible factor (HIF)-1α. The present study investigated whether the same is true in cardiac muscle. Male F344 rats were given a glucocorticoid receptor blocker (RU486) or no drug beginning five days before and throughout a fifteen-day exposure to 17,200 feet simulated in a hypobaric chamber or remained at Fort Collins elevation at 5,003 feet. Cardiac tissue was collected and analyzed for expression of GR, HIF1-α, VLCAD (a fatty acid oxidation enzyme), and each of the five complexes involved in (OXPHOS) oxidative phosphorylation. Current data indicates that while HH had no effect on cardiac GR expression, HIF1-α protein levels were elevated in the right ventricle (RV) and left ventricle (LV). Consistent with this finding, VLCAD expression was lower in the RV, with no effect of RU486 treatment, while the opposite trend was previously seen in skeletal muscle. Taken together, our results thus far indicate that in contrast to skeletal muscle, HIF1-α, rather than GR signaling, may play an important role in cardiac responses to HH.Item Open Access Beyond the game: understanding the neuropathology and enduring impacts of chronic traumatic encephalopathy(Colorado State University. Libraries, 2024-12-13) Lovejoy, Mindy, authorChronic Traumatic Encephalopathy (CTE) is a progressive neurodegenerative disease characterized by aggregation of phosphorylated tau as well as astrogliosis. Currently, CTE can only be diagnosed post-mortem and is most likely to be found in former professional athletes, especially in contact sports. However, military veterans and domestic violence victims may also suffer from this disease, increasing the prevalence. CTE is correlated to the number of traumatic brain injuries (TBI) or subconcussive impacts received, usually in childhood or adolescence. Mild TBI induces mechanisms to regain homeostasis which include a hypermetabolic state, increased intracellular calcium, and inflammatory signaling molecules in the acute phase. After the acute phase, all of these proteins and mechanisms are downregulated to create depressed neuronal signaling, neuronal death, and glial cell pathology. The immune response to mTBI causes a permeable blood-brain barrier (BBB) which leads to further neuroinflammation and further vascular injury. Post-mortem studies on brains with CTE show progressive aggregation of phosphorylated-tau neurofibrillary tangles (NFTs), diffuse axonal injury (DAI), and accumulations of thread-like astrocytes. Gross cerebral atrophy, widening of the ventricles, and wider sulcal depths are also indicative of CTE diagnosis. The McKee Staging Scheme allows for characterization and comparison of varying severities of CTE between individuals. These changes in brain chemistry can be seen through behavioral, motor, and memory symptoms in patients, similar to those in Alzheimer's Disease. A common symptom of CTE is abnormal mood changes which include apathy, depression, and aggression. The NFTs of p-tau have neurotoxic effects and destabilize microtubules. Astrocyte pathology also leads to decreased gliotransmitter release and therefore fewer neuronal depolarizations. Due to plasticity of the brain, this may lead to neuronal death and pruning. Though there are no conclusive results of the mechanisms which make TBI or repetitive head injury (RHI) transform into the neurodegenerative disease, research into connections between the two is ongoing. Chronic neuroinflammation, a permeable BBB, and an autoimmune response may contribute to the pathophysiology and progression of CTE. Currently, researchers are working to find a way to diagnose CTE before patient death. So far, blood-based biomarkers demonstrate the most promising possibilities. Drawbacks of blood-based biomarkers, such as lack of protein specificity, still exist. The studies reviewed in this paper highlight significant findings in current academic research, identify those most at risk for development of CTE, and suggest possible modes of CTE development after TBI or RHI. The findings demonstrate the importance of education and prevention in youth sports and demand major sports organizations to take responsibility for the health and safety of their athletes. The data also finds that future research will be critical for diagnosis, treatment, and prognosis for patients with CTE.Item Open Access Avian Aspergillosis: experiences in raptor rehabilitation(Colorado State University. Libraries, 2024) Procopio, Ally, authorRaptors, also called the birds of prey, are a group of birds, including eagles, hawks, falcons, owls, and vultures, which are threatened with declining populations and extinction globally. Commonly found at the highest trophic level, raptors are important top down regulators in ecosystems, helping to manage prey populations by acting as predators and controlling disease and aiding in nutrient recycling by acting as scavengers. Because of their importance in ecosystem health, and in providing valuable ecosystem services to humans, raptor conservation and rehabilitation is an important field. Rehabilitation centers assist raptors that are sick or injured, allowing them to recover so that they may be released, helping prevent the loss of that individual from the population. A large threat to raptors in rehabilitation programs is the fungal respiratory infection Aspergillosis. Aspergillosis is a zoonotic disease with high mortality rates that affects a wide range of animals, however birds, especially raptors in rehabilitation programs, have one of the highest risks of infection. This thesis acts as a literature review for avian aspergillosis, highlighting its importance in rehabilitation and conservation of raptors. It details the risk factors of infection, symptoms, diagnosis, treatment, and prevention of the disease. In addition, it addresses the emergence of azole resistance in the fungal pathogen Aspergillus fumigatus from a One Health perspective, highlighting the connection between birds, the spread of resistant strains through the environment, and the potential for human infection. In addition, it includes a reflection on time spent working in raptor rehabilitation.Item Open Access An analysis of common calcaneal tendon disruption in canids(Colorado State University. Libraries, 2024-12-13) Foster, Sophie, authorMy senior honors thesis project, "An Analysis of Common Calcaneal Tendon Disruption in Canids," aims to demonstrate knowledge of a prevalent condition seen in veterinary medicine. This project consists of a literature review analyzing common calcaneal tendon disruption in canines that describes the anatomy, etiology, prevalence, symptoms, diagnostics, and associated treatments. To accompany the literature review are two skeletal articulations showcasing a real-life example of the canine anatomy relevant to this condition. One articulation is the caudal end (or back end) and a canine, which includes the right and left pelvic limbs, the pelvis, and the lumbar and caudal vertebrae. Another articulation of a canine pelvic limb was created as a model to imitate the common calcaneal tendon and demonstrate an avulsion, or detachment, from its bony insertion point. This model will be given to the animal anatomy lab at CSU to assist with student learning. Lastly, a presentation highlighting all of the information and material gathered throughout this project was created and shared with faculty. After completing this project, I have become much more knowledgeable on common calcaneal tendon disruptions in canines and more familiar with the process of articulating skeletal models. I am very grateful for this opportunity and all the experiences that have led me to this moment!Item Open Access Finding the purrfect solution: an evaluation of sterilization methods in cats(Colorado State University. Libraries, 2024-12-09) Guertin, Madalyn E., authorThere are millions of domesticated cats in the world and most of them are strays. The growing population of stray cats poses a public health risk and contributes to the endangerment and sometimes extinction of various small wildlife species that the cats hunt. Cat overpopulation also raises ethical concerns due to poor welfare and quality of life. Furthermore, many owners seek alternative, non-surgical methods of fertility control for many reasons such as to avoid some health effects, possibility of complications, and concerns related to cost. This review analyzes different methods of fertility control available in cats to help determine the best options for both owned and feral cat populations. Based on current research, surgical procedures such as ovariectomies, ovariohysterectomies, orchidectomies, and cryptorchidectomies may be better suited for stray cat populations until other options such as immunocontraceptives or anti-Müllerian hormone transgene prove to work for much longer periods of time. Fertility control options such as progestins, melatonin, and Deslorelin may be better options for cats meant for breeding purposes because these are easily reversible and maintain behaviors associated with the hormonal cycle. For cats that clients do not intend to breed, the anti-Müllerian hormone transgene and surgical procedures such as ovariectomies, ovariohysterectomies, orchidectomies, and cryptorchidectomies may be the best options.