Laboratory and Basic Science Research Commons^™

Disrupted Circadian Rhythms Affect Hallmark Pathologies In Alzheimer’S Disease-Related Mouse Models, Valeria Buzinova

Theses and Dissertations--Molecular and Cellular Biochemistry

Alzheimer’s Disease (AD) is a complex neurodegenerative disease with two hallmark pathologies: extracellular amyloid-b (Ab) and intracellular neurofibrillary tangles (NFTs). Ab is proteolytically processed from amyloid precursor protein (APP) by b-secretase and g-secretase as a monomeric peptide prone to aggregation. Eventually, the aggregate-prone monomers will form dense plaques that are difficult to break down and remove. These plaques begin to deposit into the cortex decades prior to the formation of NFTs and the onset of cognitive decline. NFTs are comprised of hyper-phosphorylated tau. Tau is a protein that serves to promote and stabilize the formation of microtubules. The formation of …

Revolutionizing Our Understanding Of Specific Platelet-Pathogen Interactions, Hammodah Rawhi Hammodah Alfar

Theses and Dissertations--Molecular and Cellular Biochemistry

Aside from their classical role in maintaining hemostasis, platelets are considered first-line vascular guardians that influence both the innate and adaptive immune systems. This is mediated by either direct interactions with immune cells or through the release of pre-stored cytokines and chemokines upon interacting with pathogens such as viruses. While this establishes platelets as potential players in the response to pathogens, it remains unclear what platelets can do with pathogens and how important that is to immune responses, especially against viruses. Most systemic viremias, such as HIV-1, present with mild thrombocytopenia, which is mediated through several mechanisms such as a …

Effects Of Unilateral Lower Limb Suspension On Quadriceps’ Structure And Contractile Function, Eve N. Elmore

Theses and Dissertations--Kinesiology and Health Promotion

BACKGROUND: Muscle unloading such as bed rest or space flight decreases strength and cross-sectional area concomitant with a slow-to-fast fiber type shift, of anti-gravitational muscles such as the quadriceps. Diffusion tensor imaging (DTI) quantifies tissue anisotropic properties such as Fractional Anisotropy, Mean Diffusivity, Axial Diffusivity, and Radial Diffusivity, as well as muscle volume, fascicle length, and physiological cross-sectional area, and has recently been adapted to assess skeletal muscle structure. In skeletal muscle, anisotropic properties correlate with muscle fiber type and contractile function and may be responsive to unloading-induced atrophy.

PURPOSE: To assess the changes in quadriceps’ size, anisotropy, and contractile …

Inhibiting Pi3k/Akt To Enhance Brain Uptake Of Anticancer Agents In Glioblastoma, Louis Rodgers

Theses and Dissertations--Pharmacy

Glioblastoma (GBM) is the deadliest and most common malignant CNS tumor. Despite advances in understanding its biology and the development of targeted therapies, effective treatment options remain limited. As a result, patient survival rates are dismal, with a 5-year survival rate of only 6.8% and an overall survival of less than two years. This poor outcome is partly due to our inability to treat GBM cells that infiltrate the whole brain. Focal treatments like surgery and radiotherapy alone are insufficient due to these invasive tumor cells. Therefore, chemotherapy following resection and irradiation of the primary tumor is essential to eliminate …

The Delineation Of Platelet Pathology In Cardiometabolic Disease, Chi Peng

Theses and Dissertations--Pharmacology and Nutritional Sciences

Obesity is a multifactorial disease with many comorbidities leading to multiorgan dysfunction. Current studies point towards dysregulation of platelet signaling as a driver for increased risk of cardiovascular disease and stroke. The exact mechanisms remain elusive due to the complex interplay of factors involved, warranting the need to further understand how platelets are affected. Our preliminary data evaluating changes in platelet and coagulation parameters from bariatric patients showed that obesity did not affect platelet count or clotting time as demonstrated in INR values. However, female patients had increased bleeding events before surgery that were decreased after surgery. Due to limitations …

The Development And Characterization Of Nanobodies Specific To Protein Tyrosine Phosphatase 4a3 (Ptp4a3/Prl-3) To Dissect And Target Its Role In Cancer., Caroline Smith

Theses and Dissertations--Molecular and Cellular Biochemistry

Protein Tyrosine Phosphatase 4A3 (PTP4A3 or PRL-3) is an oncogenic dual-specificity phosphatase that drives tumor metastasis, promotes cancer cell survival, and is correlated with poor patient prognosis in a variety of solid tumors and leukemias. The mechanisms that drive PRL-3’s oncogenic functions are not well understood, in part due to a lack of research tools available to study this protein. The development of such tools has proven difficult, as the PRL family is ~80% homologous and the PRL catalytic binding pocket is shallow and hydrophobic. Currently available small molecules do not exhibit binding specificity for PRL-3 over PRL family members, …

Safety In The Woods: Studying The Effectiveness Of The Kentucky Master Logger Program, Austin Winn Leake

Theses and Dissertations--Community & Leadership Development

Logging is a dangerous field; in this study the researcher looks to see the knowledge both before and after professional loggers participate in the Kentucky Master Logger Program. This information was used to see the overall effectiveness of the Kentucky Master Logger Program. The researcher found an overall improvement in logging professionals’ perceptions and understanding of logging safety. The researcher recommends creating an emphasis on a safe work culture through safety incentives and a greater focus on less used personal protective equipment such as insecticide

Investigating The Effects Of In-Vivo Therapeutics Hypoxia Treatment Paradigms In Neurite Outgrowth Patterns, Jae Hyun Yoo

Theses and Dissertations--Medical Sciences

Spinal cord injury, specifically in the cervical C3-C4 region of the cervical spine, contributes to impaired breathing and a diminished quality of life. Therefore it is important to find effective and safe therapeutics to restore breathing function. Indeed, there are a myriad of research being performed in addition to valuable collaboration amongst different institutions. As such, inspired by a previous experiment, we decided to test our hypothesis that an enriching environment consisting of different hypoxic environments - sustained and intermittent hypoxia alongside normoxia - would result in neurite outgrowth. Moreover, we hypothesized that sustained hypoxia would result in the greatest …

Novel Mechanism Of Endogenous Pancreatic Cancer Cell Expression Of Immune Checkpoint Programmed Cell-Death 1 Protein (Pd-1) Inducing Epithelial-To-Mesenchymal Transition (Emt) Through The Met Pathway And Promoting Cancer Progression In An Immune-Independent Process, Megan M. Harper

Theses and Dissertations--Clinical and Translational Science

Pancreatic ductal adenocarcinoma (PDAC) remains one of the deadliest cancers with few treatment options, necessitating an urgent need for novel therapeutics. Immuno-oncologic (IO) therapies have revolutionized anti-cancer regimens in the past decade but typically involve reactivation of adaptive immune responses. In particular, immune checkpoint PD-1 is traditionally expressed only on immune cells while PD-L1 (PD-1 ligand) is overexpressed on cancer cells. When tumor-endogenous PD-L1 binds the PD-1 receptor on T-cells, the immune cells undergo anergy resulting in self-tolerance and cancer cell immune evasion. However, contrary to standard dogma, we previously demonstrated tumor-endogenous PD-1 expression in PDAC. Our data indicated that …

Regulation Of Skeletal Muscle Plasticity By The Gut Microbiome, Taylor R. Valentino

Theses and Dissertations--Physiology

Recent evidence suggests that the gut microbiome could play a role in skeletal muscle plasticity, providing novel treatments for muscle wasting diseases and/or performance enhancements. I first sought to determine if the gut microbiome is necessary for skeletal muscle adaptation to exercise. Forty-two, four-month old, female C57Bl/6J underwent nine weeks of weighted wheel running or remained in cage with a locked wheel, without or without the administration of antibiotics (treated). In response to wheel running, I found that antibiotic depletion of the microbiome led to a blunted hypertrophic response in the soleus muscle as measured by normalized muscle wet weight …

Genetic Mouse Models Of Liver Disease: Potential Roles Of Zhx2 (Afr1) And Afr2 In Damage And Regeneration, Courtney P. Turpin

Theses and Dissertations--Pharmacology and Nutritional Sciences

The liver is the largest internal organ in mammals and responsible for carrying out various processes, including lipid and carbohydrate metabolism, detoxification of chemicals, and production of serum proteins. Liver damage, which can be caused by a variety of agents including viral infection, environmental toxins, alcohol and excessive dietary fats, can cause dysregulation of these critical functions, leading to worsening liver pathophysiology and impacting health. However, the liver has the remarkable ability to regenerate when damaged. Hepatocytes, which comprise a majority of liver cells, are relatively quiescent under healthy conditions. Upon injury, remaining hepatocytes can proliferate to recover from liver …

Correlating The Physicochemical Properties Of Magnesium Stearate With Tablet Dissolution And Lubrication, Julie L. Calahan

Theses and Dissertations--Pharmacy

Magnesium stearate (MgSt) is the most commonly used pharmaceutical excipient and is present in over half the tablet formulations on the market. In spite of its popularity as an effective lubricant, it has been repeatedly recognized that there is significant variability between MgSt samples, which can cause inconsistent lubrication between batches of MgSt. The hypothesis of this research is that the batch-to-batch variability in tablet lubrication and dissolution observed in tablet formulations containing different MgSt samples can be correlated with differences in MgSt physicochemical properties (fatty acid salt composition, crystal hydrate form, particle size and surface area). Developing correlations between …

Crystal Structure Of Zymonic Acid And A Redetermination Of Its Precursor, Pyruvic Acid, Dominik Heger, Alexis J. Eugene, Sean R. Parkin, Marcelo I. Guzman

Chemistry Faculty Publications

The structure of zymonic acid (systematic name: 4-hy­droxy-2-methyl-5-oxo-2,5-di­hydro­furan-2-carb­oxy­lic acid), C₆H₆O₅, which had previously eluded crystallographic determination, is presented here for the first time. It forms by intra­molecular condensation of parapyruvic acid, which is the product of aldol condensation of pyruvic acid. A redetermination of the crystal structure of pyruvic acid (systematic name: 2-oxo­propanoic acid), C₃H₄O₃, at low temperature (90 K) and with increased precision, is also presented [for the previous structure, see: Harata et al. (1977). Acta Cryst. B33, 210–212]. In zymonic acid, the hy­droxy­lactone ring …

Mechanisms Of Trinucleotide Repeat Instability During Dna Synthesis, Kara Y. Chan

Theses and Dissertations--Toxicology and Cancer Biology

Genomic instability, in the form of gene mutations, insertions/deletions, and gene amplifications, is one of the hallmarks in many types of cancers and other inheritable genetic disorders. Trinucleotide repeat (TNR) disorders, such as Huntington’s disease (HD) and Myotonic dystrophy (DM) can be inherited and repeats may be extended through subsequent generations. However, it is not clear how the CAG repeats expand through generations in HD. Two possible repeat expansion mechanisms include: 1) polymerase mediated repeat extension; 2) persistent TNR hairpin structure formation persisting in the genome resulting in expansion after subsequent cell division. Recent in vitro studies suggested that a …

Chronic Low Intensity Continuous And Interval Training Prevent Heart Failure-Related Coronary Artery Stiffness, An Ouyang

Theses and Dissertations--Kinesiology and Health Promotion

Heart failure (HF) induced by aortic pressure over-load is associated with increased coronary artery stiffness. Perivascular adipose tissue (PVAT) and advanced glycation end products (AGE) both promote arterial stiffness. However, the mechanisms by which coronary PVAT promotes arterial stiffness and the efficacy of exercise to prevent coronary stiffness are unknown. The present study hypothesized both chronic continuous and interval exercise training would prevent coronary artery stiffness associated with inhibition of PVAT secreted AGE. Yucatan mininature swine were divided into four groups: control-sedentary (CON), aortic-banded sedentary heart failure (HF), aortic-banded HF continuous exercise trained (HF+CONT), and aortic-banded HF interval exercise trained …

Effectiveness Of A Physical Activity Enhancing Program For Use During Indoor Recess, Cassandra M. Blase

Theses and Dissertations--Kinesiology and Health Promotion

Purpose: The purpose of this study was to determine if a novel physical activity intervention game (Bingocize®) designed for use in confined spaces and modified to include age appropriate activities would increase the time spent engaged in physical activity (PA) during indoor recess. Methods: Fifty-two third grade children wore triaxial accelerometers during three different recess conditions. The recess conditions included: “typical” indoor recess (TIR), indoor recess with children engaged in Bingocize® (IRB), and “typical” outdoor recess (TOR). Results: There were significant (p < 0.05) differences among the recess conditions for the time spent in sedentary, light, moderate-to-vigorous physical activity (MVPA) intensity categories, as well as PA counts, and steps. During IRB, TIR, and TOR the subject were sedentary 42.4% (±0.10), 71.9%(±0.10), and 17.5% (±0.10) of the recess time, respectively. During IRB, TIR and TOR the subjects spent 43.4%(±0.10), 18.5%(±0.10), and 74.2%(±0.12) engaged in MVPA, respectively. Conclusions: These results indicate that Bingocize® promotes increased PA during times when inclement weather necessitates indoor recess and larger space requirements for activity are not available.

Mechanisms And Potential Therapy On Disrupted Blood Pressure Circadian Rhythm In Diabetes, Tianfei Hou

Theses and Dissertations--Pharmacology and Nutritional Sciences

Arterial blood pressure (BP) undergoes a 24-hour oscillation that peaks in the active day and reaches a nadir at night during sleep in humans. Reduced nocturnal BP fall (also known as non-dipper) is the most common disruption of BP circadian rhythm and is associated with increased risk of untoward cardiovascular events and target organ injury. Up to 75% of diabetic patients are non-dippers. However, the mechanisms underlying diabetes associated non-dipping BP are largely unknown. To address this important question, we generated a novel diabetic db/db-mPer2^Luc mouse model (db/db-mPer2^Luc) that allows quantitatively measuring of mPER2 protein oscillation …

Measured Soil Hydraulic Properties As Rzwqm2 Input To Simulate Soil Water Dynamics And Crop Evapotranspiration, Saadi Sattar Shahadha

Theses and Dissertations--Plant and Soil Sciences

Agricultural system models integrate many different processes that cannot all be measured in field experiments and help quantify soil water dynamics, crop evapotranspiration, and crop growth with high temporal resolution. Understanding soil water dynamics and crop evapotranspiration is essential to improve agricultural management of field crops. For example, the interaction between nitrogen application rate and water dynamics is not sufficiently understood. In most cases, model simulations deviate from field measurements, especially when model input parameters are indirectly and unspecifically derived. The extent to which measured soil hydraulic property inputs decrease the discrepancy between measured and simulated soil water status is …

Oxidation Of Substituted Catechols At The Air-Water Interface: Production Of Carboxylic Acids, Quinones, And Polyphenols, Elizabeth A. Pillar, Marcelo I. Guzman

Chemistry Faculty Publications

Anthropogenic activities contribute benzene, toluene, and anisole to the environment, which in the atmosphere are converted into the respective phenols, cresols, and methoxyphenols by fast gas-phase reaction with hydroxyl radicals (HO(•)). Further processing of the latter species by HO(•) decreases their vapor pressure as a second hydroxyl group is incorporated to accelerate their oxidative aging at interfaces and in aqueous particles. This work shows how catechol, pyrogallol, 3-methylcatechol, 4-methylcatechol, and 3-methoxycatechol (all proxies for oxygenated aromatics derived from benzene, toluene, and anisole) react at the air-water interface with increasing O3(g) during τc ≈ 1 μs contact time and contrasts their …

Reactivity Of Ketyl And Acetyl Radicals From Direct Solar Actinic Photolysis Of Aqueous Pyruvic Acid, Alexis J. Eugene, Marcelo I. Guzman

Chemistry Faculty Publications

The variable composition of secondary organic aerosols (SOA) contributes to the large uncertainty for predicting radiative forcing. A better understanding of the reaction mechanisms leading to aerosol formation such as for the photochemical reaction of aqueous pyruvic acid (PA) at λ ≥ 305 nm can contribute to constrain these uncertainties. Herein, the photochemistry of aqueous PA (5-300 mM) continuously sparged with air is re-examined in the laboratory under comparable irradiance at 38° N at noon on a summer day. Several analytical methods are employed to monitor the time series of the reaction, including (1) the derivatization of carbonyl (C═O) functional …

Ionic Regulation Of Critical Cellular Processes In Non-Excitable Cells, Brandon M. Franklin

Theses and Dissertations--Biology

There are long-standing hypotheses that endogenous ion currents act to control cell dynamics in development, wound healing and regeneration. However, the mechanisms employed by cells to detect the electric field (EF) and translate it into a discernable message to drive specific cell behaviors, such as migration, proliferation and differentiation, are not well understood. A better understanding of how cells are able to sense EFs and react to them is vital to understanding physiological mechanisms are involved in regeneration. Ion channel signaling provides a reasonable suspect for mediating these effects based on their documented involvement in proliferation, migration and differentiation.

To …

Evolution Of Equine Arteritis Virus During Persistent Infection In The Reproductive Tract Of The Stallion And The Male Donkey, Bora Nam

Theses and Dissertations--Veterinary Science

Equine arteritis virus (EAV) establishes persistent infection in the stallion reproductive tract, and the carrier stallion continues to shed virus in semen for weeks to years or lifelong. The objective of this study was to elucidate the intra-host evolution of EAV during persistent infection in stallions. Seven EAV seronegative stallions were experimentally infected with EAV KY84 strain and followed for 726 days post-infection, and sequential clinical samples including semen were collected for virus isolation and next-generation sequencing (NGS). In addition, archived sequential semen samples from two stallions that were naturally infected with EAV KY84 for a long-period (up to 10 …

Calcitriol Increases Ceramide, Diacylglycerol, And Expression Of Genes Involved In Lipid Packaging In Skeletal Muscle, Grace Elizabeth Jefferson

Theses and Dissertations--Kinesiology and Health Promotion

Background: Vitamin D is crucial for skeletal muscle function. 25-hidroxyvitamin D (25(OH)D) has been correlated with skeletal muscle mass and intramyocellular lipid (IMCL) content. The purpose of this study was to understand how calcitriol, the active vitamin D metabolite, directly affects myocellular size and lipid partitioning.

Methods: C₂C₁₂ myotubes were treated with calcitriol (100nM) or vehicle control for 24 or 96 h. Myotube diameter and protein synthesis rate were measured to determine effects of calcitriol on myocellular size. Intramyocellular triacylglycerol (IMTG), diacylglycerol (DAG), and ceramide content were measured by LC/MS. Expression of genes involved in lipid packaging …

Deep Sleep, Cognition, Body Weight, Body Temperature, And Behavioral Distress Responses To New Onset Psychosocial Stressors Are Blunted With Age In Male F344 Rats, Kendra E. Hargis

Theses and Dissertations--Pharmacology and Nutritional Sciences

Complaints associated with aging, including cognitive deficits and sleep loss, are highly prevalent and negatively impact quality of life. Further, with increased age, humans are also more likely to experience new-onset psychosocial stressors, such as divorce, loss of a spouse, and social isolation. Stress has detrimental consequences that in many ways parallel the effects of aging on sleep and cognition. The long-standing stress/ glucocorticoid hypotheses of brain aging posit that stress exposure exacerbates aging symptoms, and extensive prior studies have shown that early life stress exposure does worsen phenotypic aging symptoms. However, despite its prevalence in aged humans, little basic …

The Role Of The Ace2/Ang-(1-7)/Masr Axis In The Development Of Obesity-Hypertension In Male And Female Mice, Yu Wang

Theses and Dissertations--Pharmacology and Nutritional Sciences

Obesity is strongly associated with hypertension and cardiovascular diseases. An activated renin-angiotensin system (RAS) has long been suggested as a critical contributor to elevated blood pressure with obesity. Angiotensin II (AngII), the main effector of an activated RAS, can be catabolized by angiotensin-converting enzyme 2 (ACE2) to form angiotensin-(1-7) (Ang-(1-7)), which, acting through the mas receptor (MasR), has been shown to oppose the effects of an activated RAS. Therefore, further understanding of the mechanisms of this counter-regulatory arm, called the ACE2/Ang-(1-7)/MasR axis, may lead to new therapies for obesity-induced hypertension. Previously, we demonstrated that differences in the regulation of ACE2 …

Heterogeneous Oxidation Of Catechol, Elizabeth A. Pillar, Ruixin Zhou, Marcelo I. Guzman

Chemistry Faculty Publications

Natural and anthropogenic emissions of aromatic hydrocarbons from biomass burning, agro-industrial settings, and fossil fuel combustion contribute precursors to secondary aerosol formation (SOA). How these compounds are processed under humid tropospheric conditions is the focus of current attention to understand their environmental fate. This work shows how catechol thin films, a model for oxygenated aromatic hydrocarbons present in biomass burning and combustion aerosols, undergo heterogeneous oxidation at the air–solid interface under variable relative humidity (RH = 0–90%). The maximum reactive uptake coefficient of O₃(g) by catechol γ_O3 = (7.49 ± 0.35) × 10^–6 occurs for …

Clinical Significance Of The Integrin Α6Β4 In Human Malignancies, Rachel L Stewart, Kathleen L O'Connor

Pathology and Laboratory Medicine Faculty Publications

Integrin α6β4 is a cellular adhesion molecule that binds to laminins in the extracellular matrix and nucleates the formation of hemidesmosomes. During carcinoma progression, integrin α6β4 is released from hemidesmosomes, where it can then signal to facilitate multiple aspects of tumor progression including sustaining proliferative signaling, tumor invasion and metastasis, evasion of apoptosis, and stimulation of angiogenesis. The integrin achieves these ends by cooperating with growth factor receptors including EGFR, ErbB-2, and c-Met to amplify downstream pathways such as PI3K, AKT, MAPK, and the Rho family small GTPases. Furthermore, it dramatically alters the transcriptome …

Regulation Of Pancreatic Β-Cell Function By The Renin-Angiotensin System In Type 2 Diabetes, Robin C. Shoemaker

Theses and Dissertations--Pharmacology and Nutritional Sciences

Diet-induced obesity promotes type 2 diabetes (T2D). Drugs that inhibit the renin-angiotensin system (RAS) have been demonstrated in clinical trials to decrease the onset of T2D. Previously, we demonstrated that mice made obese from chronic consumption of a high-fat (HF) diet have marked elevations in systemic concentrations of angiotensin II (AngII). Pancreatic islets have been reported to possess components of the renin-angiotensin system (RAS), including angiotensin type 1a receptors (AT1aR), the primary receptor for AngII, and angiotensin converting-enzyme 2 (ACE2), which negatively regulates the RAS by catabolizing AngII to angiotensin-(1-7) (Ang-(1-7)). These two opposing proteins have been implicated in the …

Designing Anthradithiophene Derivatives Suitable For Applications In Organic Electronics And Optoelectronics, Rawad Kamal Hallani

Theses and Dissertations--Chemistry

Anthradithiophene (ADT) derivatives have proven to be a front-runner in the world of small molecule semiconductors for organic electronics and optoelectronics. This is mainly due to the improved stability, easy tuning of chemical and physical properties, and impressive device performance that these molecules possess, especially in organic field effect transistors (OFET) and organic photovoltaics (OPV). The second chapter of this dissertation shows that reducing the amount of alkylsilylethynyl groups, used for functionalizing and solubilizing the ADT backbone, does alter the chemical, physical and crystallographic properties of ADTs. These changes offer the opportunity to study and observe different intermolecular interactions as …

A Brief Elevation Of Serum Amyloid A Is Sufficient To Increase Atherosclerosis, Joel C. Thompson

Theses and Dissertations--Pharmacology and Nutritional Sciences

Cardiovascular disease is now the leading cause of death worldwide. Serum amyloid A (SAA), a positive acute phase reactant, along with C-reactive protein is used clinically as a marker of cardiovascular disease risk. However, recent data has shed light on a possible causal role of SAA in the development of atherosclerosis, the most pervasive form of cardiovascular disease. Several inflammatory diseases such as diabetes and obesity are known to confer increased risk of developing cardiovascular disease. Individuals with these diseases all have modest but persistent elevation of SAA. To determine if SAA caused the development of atherosclerosis, apoe^-/-chow …