Medicine and Health Sciences Commons^™

Flanker Task Performance In Young And Older Adults: A Behavioral And Erp Study, Fatima Medrano

Dissertations, Theses, and Capstone Projects

Research suggests that as we get older, executive function abilities decline (Hasher & Zacks, 1988; Salthouse, 1996). One affected ability is that of inhibitory control, which aids in monitoring our responses to non-target stimuli or information. Current research on inhibition reveals inconsistencies across studies. Monitoring brain responses during the Flanker (used to measure inhibitory control) task may add valuable insight into the processes underlying group differences behaviorally, by studying the N200 and P300 event-related potentials which have been associated with inhibitory control processes. This study investigated whether there are differences between older and younger adults in inhibitory control and whether …

Effect Of Haemonchus Contortus Excretory/Secretory Protein On Differences In Host Neutrophil Migration, Hannah Grace Teddleton

Graduate Theses, Dissertations, and Problem Reports

An excretory/secretory (E/S) product, common to many helminths, is neutrophil inhibitory factor (NIF) which negatively affects neutrophil migration and activity. Due to differences in neutrophil accumulation between parasite resistant St. Croix STC and parasite susceptible Suffolk (SUF) sheep, we hypothesized that Hc-NIF may inhibit migration of SUF and not STC neutrophils. Previous studies have demonstrated that Hc produces NIF but is not commercially available. To test our hypothesis, neutrophils were cultured from STC and SUF sheep in the presence of Ancylostoma caninum-derived NIF (Ac-NIF) and measure chemotaxis to Interleukin-8 (IL-8), HcLA or H. contortus third-stage excretory/secretory (E/S) products. Neutrophils were …

Effects Of Patellofemoral Pain On Central Activation And Function Of The Gluteus Medius Muscle In Physically Active Females, Michelle Samuel

UNLV Theses, Dissertations, Professional Papers, and Capstones

Patellofemoral pain (PFP) is the most common knee injury among runners, military personnel, adolescents and recreationally active persons. PFP commonly presents as diffuse pain across the anterior knee that increases with activities such as running, squatting, and walking up and down stairs. Nearly 75% of patients with PFP either alter or completely stop physical activity as a result of the pain. There are numerous mechanisms that contribute to PFP symptoms; such as muscle weakness, abnormal joint mechanics and abnormal joint stress, which make it difficult to successfully treat. In addition, PFP may lead to patellofemoral joint (PFJ) osteoarthritis, a debilitating …

Tinnitus And Decreased Subcortical And Cortical Inhibition, Kenneth Vincent Morse

Dissertations - ALL

Background: The perception of tinnitus may be triggered by a reduction in inhibitory function in the central auditory nervous system. Evidence, primarily from invasive studies of animal models of tinnitus, indicates that these changes occur at both the subcortical and cortical level. Auditory evoked potential (AEP) indices of subcortical inhibition [auditory brainstem response (ABR) 〖"V/I" 〗_"amp ratio" ] and cortical inhibition [cortical auditory evoked potential (CAEP) sensory gating ratios] may provide an objective index of whether reduced subcortical and/or cortical inhibition is associated with tinnitus perception in humans. The aims of this study were to assess whether ABR and/or CAEP …

Development Of Linked-Domain Protein Inhibitors Of The E2-Conjugating Enzyme Ube2d, Anneroos E. Nederstigt

University of the Pacific Theses and Dissertations

In most eukaryotic organisms, the ubiquitination pathway is one of the most important and versatile signaling systems in use. It is integral to processes such as protein degradation and homeostasis, DNA repair cell cycle regulation, signaling and regulation, epigenetics, and many more. Ubiquitin (Ub) is a short polypeptide of 8.6 kDa, 76 residues that functions as a reversible post-translation modification (PTM). It furthermore contains 7 different lysine residues (K6, K11, K27, K29, K33, K48, K63), all of which can form isopeptide linkages with one another to link individual Ub moieties to form unique polyUb chains onto substrates. The type of …

Hypothalamic Circuits Mediating Consumption And Anxiety, Ryan Cassidy

Dissertations & Theses (Open Access)

From 1960-2016, U.S. obesity prevalence increased 13-40% and diabetes increased from 3-15%. There is an epidemic of metabesity, the aggregate metabolic disorders produced by chronic overeating. Drugs for metabesity were developed in the 1930s with limited effectiveness; agents today rely on the same principles and are similarly ineffective. Particularly surprising has been the failure of satiety enhancers; this indicates it may not be that physiologic hunger drives chronic overeating. Although hunger and satiety affect traditional reward circuitry (Cassidy & Tong 2017), evidence for the primacy of this effect is mixed. Being hungry reduces anxiety-like behavior in mice; whether the …

Impact Of Sickle Cell Disease On Executive Functioning In An Adult Population, Christina Wade

Theses and Dissertations

Children diagnosed with sickle cell disease (SCD) struggle with executive functions (EF); however, there is a paucity of research on neuropsychological outcomes in adults with SCD. This study aimed to examine differences in EF between adults with SCD and healthy controls. Thirty- one patients with SCD and 34 healthy controls (ages 18-45) participating in an IRB-approved Children’s Hospital Los Angeles (CHLA) study of cerebral blood flow underwent neuropsychological evaluation using the Delis–Kaplan Executive Function System (D-KEFS) Trail Making and Color Word Interference Tests and the Wechsler Adult Intelligence Scale - Fourth Edition (WAIS-IV) Digit Span subtest to assess various aspects …

Restructuring Of The Axon Initial Segment In Mouse Models Of Neurodevelopmental Disorders, Rachel Ali Rodriguez

UNLV Theses, Dissertations, Professional Papers, and Capstones

Neurodevelopmental disorders (NDDs) affect more than 36% of children in countries with low- and middle- incomes (Boivin, 2015; McCoy, 2016). Interestingly, these heterogeneous disorders share a high incidence of epileptic seizures, suggesting a shared pathology. Seizures result when neuronal firing activity becomes disturbed and neurons fire excessively or in unregulated patterns. A key site in the control of neuronal firing patterns is the axon initial segment (AIS), where the local density of proteins and the morphology of the AIS in part determine the firing of neurons. We hypothesized that a disruption in the morphology and/or composition of the AIS can …

Probing Of Carbohydrate-Protein Interactions Using Galactonoamidine Inhibitors, Jessica B. Pickens

Graduate Theses and Dissertations

Glycoside hydrolases are ubiquitous and one of the most catalytically proficient enzymes known, and thus understanding their mechanisms are crucial. Most research has focused on the interaction of the glycon of substrates and their inhibitors within the active site of glycoside hydrolases. The inhibitors employed to probe these interactions generally had small aglycons (i.e. a hydrogen atom, amidines, small aliphatic groups, or benzyl groups). Here, the interactions of the aglycon with glycoside hydrolases are examined by probing the active sites with a library of 25 galactonoamidines. The studies described in this dissertation aim to increase the understanding of stabilization of …

Rumen Microbial Culture Library And In Vitro Analysis Of Selected Bacterial Species On Colonization Resistance Against Bovine Enteric Pathogens, Maria Antony

Electronic Theses and Dissertations

The anaerobic habitat of the four chambers in ruminant’s foregut plays a vital role in the fermentation of the food by the active involvement of the residing microbial community. The cultivability and the potential role of rumen bacteria in the field of livestock production, host health and immunity are important to study. The developed anaerobic culturing techniques enable us to culture and screen different rumen bacteria to study the anti-pathogenic effects. Whole genome sequencing and analysis help us to understand the genome level characteristics of the rumen bacterial species individually. Since the majority of the rumen biosphere is still not …

Preventing Prejudiced Psychological Practice: Social Justice Education In Undergraduate Psychology Programs, Rachel Roewer

Global Honors Theses

In order to provide sufficient mental health care services and produce ethical research, psychologists must be motivated to inhibit their personal biases. Bias in psychological research and mental health care settings can contribute to the perpetuation of oppression, preventing clients who identify with marginalized groups from receiving adequate mental health services. Prejudice amongst mental health care providers can influence misdiagnosis and wrongful prescription of medication. Psychological research informs clinical practices, thus biased research can lead to prejudiced mental health care practices. To ensure that members of marginalized groups receive effective health care, there is a global need for ethical, culturally …

Behavior Coding Strategies: Population Coupling And The Functional Role Of Excitatory/Inhibitory Balance In Primary Motor Cortex, Patrick Aaron Kells

Graduate Theses and Dissertations

The complexities of an organism’s experience of- and interaction with the world are emergent phenomena produced by large populations of neurons within the cerebral cortex and other brain regions. The network dynamics of these populations have been shown to be sometimes synchronous, with many neurons firing together, and sometimes asynchronous, with neurons firing more independently, leading to a decades-old debate within the neuroscience community. This discrepancy comes from viewing the system at two different scales; at the single cell level, the spiking activity of two neurons within cortex tend to be rather independent, but when the average activity of a …

The Effect Of Ammonia On The Germination And Outgrowth Of Bacillius Globigii, Joseph B. Kunicki

Theses and Dissertations

This research investigated the germination and outgrowth of Bacillus globigii in the presence of ammonia in laboratory scale experiments. Germination was measured by monitoring the release of dipicolinic acid, an organic compound present in bacterial spores, while outgrowth was measured using phase-bright microscopy and semi-automated counting procedures. The ammonia-N concentrations investigated generally did not cause statistically significant differences in the initial 1-hr germination rates or the average 3-hr outgrowth rates of Bacillus globigii spores in batch style experiments. The average 1-hr germination rates observed in the absence of ammonia-N was 0.0258 hr^-1 for the water and buffer controls and …

Determination Of The Effects That A Previously Uncharacterized Secreted Product From Klebsiella Pneumoniae Has On Citrobacter Freundii And Enterobacter Cloacae Biofilms, Cody M. Hastings

Undergraduate Honors Theses

More so than ever, Multiple Drug Resistant (MDR) bacteria are on the rise due to overuse of antibiotics along with natural selection for adaptations that enhance drug-resistant properties. One particular bacterial family, Enterobacteriaceae, has been problematic, exhibiting several bacterial members that have developed a precipitous resistance to modern antibiotics and are also primary causative agents of nosocomial, or hospital acquired, infections. Citrobacter freundii (CF) and Enterobacter cloacae (ECL) are two species of the Enterobacteriaceae family causing significant medical concern due to their role in producing numerous opportunistic infections such as bacteremia, lower respiratory tract infections, urinary tract infections, and endocarditis. …

Using Semiphysiologically-Based Pharmacokinetic (Semi-Pbpk) Modeling To Explore The Impact Of Differences Between The Intravenous (Iv) And Oral (Po) Route Of Administration On The Magnitude And Time Course Of Cyp3a-Mediated Metabolic Drug-Drug Interactions (Ddi) Using Midazolam (Mdz) As Prototypical Substrate And Fluconazole (Flz) And Erythromycin (Ery) As Prototypical Inhibitors, Mengyao Li

Theses and Dissertations

The purpose of the project was to investigate the impact of IV and PO routes difference for MDZ, a prototypical CYP3A substrate, and two CYP3A inhibitors (CYP3AI) -FLZ and ERY-, on the magnitude and time course of their inhibitory metabolic DDI.

Individual semi-PBPK models for MDZ, FLZ and ERY were developed and validated separately, using pharmacokinetic (PK) parameters from clinical/in-vitro studies and published physiological parameters. Subsequently, DDI sub-models between MDZ and CYP3AIs incorporated non-competitive and mechanism-based inhibition (MBI) for FLZ and ERY, respectively, on hepatic and gut wall (GW) CYP3A metabolism of MDZ, using available in-vitro/in-vivo information. Model-simulated MDZ …

Theory Of Mind And Inhibitory Processing Among Bilingual Mexican American Young Children, Sarah E. Stegall

Theses and Dissertations - UTB/UTPA

Bilingual children have been found to demonstrate advantages on tasks dependent in part or in whole on inhibitory processing compared to their language dominant and/or monolingual peers. This study examines relations among performance on theory of mind (ToM), inhibitory processing (FF), and performance on an ambiguous-figures (AF) tasks among monolingual and bilingual children. Participants included 135 Hispanic children ages 4.5 to 8 from predominately low-income families. Results revealed a relationship between FF and AF performance with ToM performance and found no differences in performance between monolingual, language-dominant, and balanced-bilingual children.

The Characterization Of Human Cytosolic Sulfotransferase 1a1: Interactions With 17Α-Ethinylestradiol, Katie Jo Glowacki

All ETDs from UAB

Human cytosolic sulfotransferases (SULTs) are a family of Phase II conjugating enzymes that facilitate the transfer of a sulfonate moiety from 3’phosphoadenosine 5’phosphosulfate (PAPS) to hydroxyl or amine groups of acceptor substrates. SULT1A1, located in many tissues throughout the human body including the liver, is important in the metabolism of many endogenous, exogenous, xenobiotic, and drug compounds. The majority of substrates for SULT1A1 are small neutral phenols including 1-naphthol and acetaminophen; however, SULT1A1 sulfates larger compounds including 17β-estradiol (E2) and raloxifene. SULT1A1 conjugates E2 with a Km of 2.3 µM and the structure of E2 is almost identical to the …

Measuring The Role Of Inhibition In Auditory Discrimination In Mice, Tazima Nur

Graduate Theses and Dissertations

Understanding how inhibitory neurons affect sensory information processing in the cerebral cortex is an ongoing goal of both neuroscience and statistical physics research. In this master's thesis research project, an experimental system has been designed and built for studying how auditory dynamic range depends on inhibitory neurons, based on observations of mouse behavior. In this thesis, firstly, the topic of inhibition and information processing has been introduced. Then two papers related to inhibition and dynamic range has been reviewed in detail. One of the papers is an experimental work that analyzes the affect of inhibition on dynamic range. The other …

Role Of Oxidative Reactive Species And Antioxidants In Metabolism And Transport Of Therapeutic Drugs, Svetlana Verenich

Theses and Dissertations

Oxidative stress (OS) is a frequent complication of various disease conditions such as Alzheimer’s and Parkinson’s disease, atherosclerosis, preeclampsia, rheumatoid arthritis, diabetes including gestational diabetes, etc. OS is defined as an imbalance between the production of reactive species and the ability of an organism to detoxify the reactive intermediates and repair the damage. As a result of OS, the excess of reactive species such as oxygen superoxide (O2-), hydroxyl radical (OH), peroxynitrite (ONOO−), 4-hydroxynonenal (4HNE), etc., have a tendency to react with nearby proteins/nucleic acids/lipids changing their functionality or inactivating them completely. The organism has many ways to protect itself …

A Study Of Possible Pre-Cognitive Advantages Of Bilingualism, Marisela Gutierrez

Open Access Theses & Dissertations

Past research has suggested that second language acquisition has a beneficial effect on the development of inhibitory control processes in children and adults. This has been referred to as the "bilingual advantage" and is most commonly quantified using the Simon task. Whether the bilingual advantage extends to precognitive mechanisms has not yet been examined. The goals of this study were to examine the bilingual advantage in university students; and to examine whether the bilingual advantage extends to the precognitive filtering mechanism of sensorimotor gating. It was predicted that, as compared to monolinguals, bilingual university students would have greater inhibitory control, …

Protection Of Macrophages J774a.1 By Purine Nucleoside Analogues From Bacillus Anthracis Mediated Necrosis, Zadkiel R. Alvarez

UNLV Theses, Dissertations, Professional Papers, and Capstones

Eight years after the lamentable anthrax attacks, major scientific effort continues to be done, in order to stop imminent acts of bioterrorism. Innovative ways of therapy against the anthrax disease are being investigated. B. anthracis, the etiological agent of the infection, has a dormant stage in its life cycle known as the endospore. When conditions become favorable spores germinate, transforming into vegetative bacteria. In inhalational anthrax, the most fatal manifestation of the disease, spores enter the organism through the respiratory track, and are phagocytosized by alveolar macrophages of the lungs. Spores are able to sense nutrient availability, activating their germination …

P-Glycoprotein And Membrane Permeability As Determinants Of Xenobiotic Bioavailability And Bioaccumulation, Xiaobing Tan

LSU Doctoral Dissertations

The ABC transporter P-glycoprotein (Pgp) and membrane permeability are determinant factors for absorption and disposition of xenobiotics. These studies investigated the effects of potential modulators of Pgp and/or membrane function on the disposition, bioavailability and bioaccumulation of environmentally relevant pharmaceuticals, tetracycline and ivermectin, and the carcinogen benzo[a]pyrene in catfish. The pesticide dieldrin and surfactant linear alkylbenzene sulfonate (LAS) were selected as mixture components thought to have potential interactions with these determinants of disposition. Initial in situ experiments demonstrated dieldrin and tetracycline both significantly inhibited biliary excretion of Pgp prototypic substrate Rhodamine-123 in isolated perfused livers. Further, dieldrin (20µM) reduced movement …