Medicine and Health Sciences Commons^™

Towards An In Vitro Model Of Testing Osteoblast Cellular Function In Contact With Various Surfaces, Raheleh Miralami

Theses & Dissertations

Past studies have shown that the success of total joint replacements depends on the biocompatibility of orthopaedic materials, which can be improved by modifying the implant surface. However, the exact roles of these modifications and their effective mechanisms are poorly understood. The objective of this study was to develop and evaluate a model system to investigate the impact of nano-structured surfaces, produced by the ion beam-assisted deposition (IBAD) technique, on biomarkers of osteointegration using an in vitro model. The IBAD technique was employed to deposit zirconium oxide (ZrO₂), Titanium oxide (TiO₂), and Titanium (Ti) nano-films on …

Sequence-Specific Extracellular Micrornas Activate Tlr7, Niming Wu

Theses & Dissertations

Toll-like receptors (TLRs) play an important role in the innate immune system. Emerging evidence shows that TLRs, especially endosomal TLRs, can participate in CNS diseases by increasing the production of proinflammatory cytokines via recognition of microRNAs (miRNAs), however which of the miRNAs are able to activate signaling and whether specific sequence motifs are involved remains incompletely defined. Here we found that numerous miRNAs induced TNF-a production across multiple myeloid cell types, including microglia, and that this effect was abolished in cells deficient of TLR7. In particular, miR-20a-5p and miR-148b-3p preferentially stimulate cytokine secretion compared to miR-20b-5p and miR-148a-3p, respectively, despite …

Dietary Polyunsaturated Fatty Acids Regulate Mammary Tumor Growth And Metastasis By Modulating Tissue Microenvironments, Saraswoti Khadge

Theses & Dissertations

Omega (ω)-6 and ω-3 polyunsaturated fatty acids (PUFAs) are essential fatty acids (FAs) and the precursors of pro- and anti-inflammatory mediators respectively. Epidemiological studies have shown a lower incidence of breast cancer (BC) in the countries where long-chain (LC)-ω-3FAs consumption is higher; however, the role of ω-3FAs in BC growth and metastasis is poorly understood. We used isocaloric, isolipidic ω-6 and ω-3 (contains LC-ω-3FAs) diets and a pair-fed model to evaluate the effects of dietary PUFAs in mammary tumor metastasis. Our studies have resulted in several novel observations including that dietary LC-ω-3FAs modulate mammary gland (MG) microenvironments in non-tumor bearing …

Early Oral Feeding After Bowel Resection, Jennifer Strang

Theses & Dissertations

Research Focus: The primary purpose of this project was to determine if there was an association of factors with time to first solid meal in gastrointestinal (GI) surgery patients and the impact solid diet has on length of stay (LOS) in the hospital, GI symptoms, and incidence of post-operative ileus (POI). A secondary purpose was to observe and describe when an oral diet was started and the progression of diet after GI surgery.

Research Methods: This study was a cross-sectional, retrospective chart review of a convenience sample in a multi-centered hospital system conducted in 84 GI resection patients …

An Evaluation Of The Use Of A Clinical Research Data Warehouse And I2b2 Infrastructure To Facilitate Replication Of Research, Bret Gardner

Theses & Dissertations

Replication of clinical research is requisite for forming effective clinical decisions and guidelines. While rerunning a clinical trial may be unethical and prohibitively expensive, the adoption of EHRs and the infrastructure for distributed research networks provide access to clinical data for observational and retrospective studies. Herein I demonstrate a means of using these tools to validate existing results and extend the findings to novel populations. I describe the process of evaluating published risk models as well as local data and infrastructure to assess the replicability of the study. I use an example of a risk model unable to be replicated …

Properties Of Synaptic Transmission From Rods And Cones In The Outer Plexiform Layer Of The Vertebrate Retina, Xiangyi Wen

Theses & Dissertations

Photoreceptors are the first neurons in the visual system. They transduce changes in light intensity into graded changes in membrane potential that are then transformed into chemical signals by regulating the release of glutamate-filled synaptic vesicles. Rod and cone photoreceptors release glutamate continuously in darkness and release slows in light. To help track rapid changes in light intensity, photoreceptors are capable of both rapid exocytosis and rapid endocytosis of synaptic vesicles.

Endocytosis is needed for recycling synaptic vesicles but also appears to be important for removing proteins and lipids from active zones to restore release site function after prior vesicle …

Electrophysiological Biomarkers Of Chemotherapy-Related Cognitive Impairment In Hematological Malignancy Patients, David E. Anderson

Theses & Dissertations

Multiple cancer populations frequently report cognitive impairment following treatment with chemotherapy agents (“chemo-brain”). Impaired neuropsychological performance is commonly reported in cognitive domains of attention and executive function. Understanding neural mechanisms underlying cognitive impairments is essential to developing prevention and rehabilitation strategies. Brain imaging studies frequently show chemotherapy-related impairments within the attentional control network, which is comprised of a constellation of cortical regions that govern reportedly impaired cognitive functions. In the current dissertation research, I developed a novel electrophysiology battery aimed at recording near-instantaneous neural activity within the attentional control network during cognitive task performance. Cancer patients diagnosed with hematological malignancy …

Alcohol Drives Oxidation-Dependent Desensitization Of Airway Cilia Motility Responsiveness, Michael Price

Theses & Dissertations

Alcohol abuse, which can impair clearance of pathogens and debris from the airway, is associated with an increase in complications and a higher mortality rate during the progression of pneumonia. With prolonged alcohol exposure, mucociliary clearance (MCC), which depends on the coordinated beating of cilia, is dysfunctional. Effective MCC relies on cAMP-dependent protein kinase (PKA) activation of ciliary beat frequency (CBF). PKA activation and stimulation of CBF are blunted with chronic exposure to alcohol. This phenomenon is known as alcohol-induced ciliary dysfunction (AICD). Previous studies have shown that concomitant feeding of mice with alcohol and antioxidants prevents AICD, suggesting a …

The Effect Of Dust Mite Extract On Esophageal Tight Junctions In Eosinophilic Esophagitis, Kyle Hinz

Theses & Dissertations

Eosinophilic Esophagitis (EE) is a chronic inflammatory disease that effects individuals of all ages. EE is mediated by an allergen response, causing the release of thymic stromal lymphopoietin (TSLP), and subsequent inflammation and eosinophil migration and infiltration of the esophagus through the activation of the JAK/STAT pathway and CD4+ T-cells. EE has typically been associated with food allergies, but studies have shown that aeroallergens can cause EE as well. Current treatments of EE have primarily focused on nonspecific methods, though anti-TSLP is beginning to be tested as a possible treatment for EE. The aim of this study was to see …

Microrna Expression And Disease Correlation In A Hispanic Lupus Cohort, Thandiwe Jere

Theses & Dissertations

Systemic Lupus Erythematosus (SLE) is a complex autoimmune disease with varying clinical presentation and severity in different ethnicities/races. Micro-RNAs (miRNAs) modulate the immune system, and there is a growing interest in their role in SLE pathogenesis and disease presentation. Studies on miRNAs expression in SLE have been done in Caucasians and Asians but no comprehensive profiling has been done in Hispanics. This cross-sectional study of a Hispanic cohort of SLE patients (n =185) and healthy controls (HC) (n =185) from the Dominican Republic determined the expression of 10 selected miRNAs and their correlation to inflammatory markers and auto-antibody production in …

The Beta-Catenin/Muc1.Ct Interaction In Pancreatic Cancer, Edwin Wiest

Theses & Dissertations

MUC1 is overexpressed in over 90% of pancreatic cancer cases, and its interaction with beta-catenin promotes progression of the disease. Various in vitro and in vivo methods show that beta-catenin and MUC1 interact by way of the cytoplasmic tail of MUC1 (MUC1.CT). This interaction occurs in the membrane of pancreatic cancer cells but is found to a smaller extent in the nucleus as well. Biophysical methods suggest that MUC1 interacts with beta-catenin through a sequence of amino acids in the tail of MUC1 that sit very near the transmembrane domain of MUC1. In pancreatic ductal adenocarcinoma cells, it appears that …

Muc4 Based Immunotherapy For Pancreatic Cancer, Kasturi Banerjee

Theses & Dissertations

Pancreatic Cancer (PC) is a lethal disease claiming approximately 45000 lives in the US in 2018, and it establishes an elaborate immunosuppressive tumor microenvironment that aids in disease pathogenesis. Immunotherapy has emerged as a strategy to target tumor cells by reprogramming patient’s immune system. Challenges present in PC immunotherapy are: i) identifying a tumor-associated antigen that could be targeted, ii) identifying adjuvants that could efficiently deliver antigens, iii) eliciting robust anti-tumor responses and iv) overcoming peripheral tolerance and immunosuppression elicited by the tumor.

Firstly, we detected circulating autoantibodies to MUC4 present in PC patients and observed that IgM autoantibodies to …