Digital Commons Network^™

Evaluating The Utility Of Protein Biomarker, S100a7, And Diagnostic Test, Straticyte, In Predicting The Progression Of Oral Dysplasia, Lachlan Mclean

Electronic Thesis and Dissertation Repository

Five-year survival of oral cancer has remained relatively unchanged despite advancements in treatment, mostly because diagnosis is often made at an advanced stage of disease. The progression of dysplasia to oral cancer often follows a stepwise progression. Histopathology is considered the ‘gold standard’ for diagnosing dysplasia and lesions at a high risk of progression to oral cancer, but lends itself to subjectivity. The protein biomarker, S100A7, in oral dysplasia and squamous cell carcinoma has shown some predictive value for the transformation of dysplasia to cancer. Straticyte, a diagnostic test utilizing S100A7 to predict the probability of progression of oral dysplasia …

The Effect Of Pigmentation On Thermoplastic And Thermoset Elastomeric Power Chain, William Taylor

Electronic Thesis and Dissertation Repository

Aim: The purpose of the study was to determine the effect of pigmentation on force levels and their degradation over time in orthodontic power chain of different chain types and manufactures.

Materials & Methods: Groups consisted of closed power chain from American Orthodontic (AO) thermoplastic (TP) in 5 colors, AO thermoset (TS) in 2 colors, Ormco TP in 4 colors, Ormco TS in 2 colors, and Rocky Mountain Orthodontics (RMO) TS in 5 colors (18 groups total, 10 chain samples in each group). Testing was performed over a period of 6 weeks at intervals of initial (T0), 1 hour (T1), …

Functional Localization Of The Frontal Eye Fields In The Common Marmoset Using Microstimulation, Janahan Selvanayagam, Kevin D. Johnston, David J. Schaeffer, Lauren K. Hayrynen, Stefan Everling

Brain and Mind Institute Researchers' Publications

Copyright © 2019 the authors. The frontal eye field (FEF) is a critical region for the deployment of overt and covert spatial attention. Although investigations in the macaque continue to provide insight into the neural underpinnings of the FEF, due to its location within a sulcus, the macaque FEF is virtually inaccessible to electrophysiological techniques such as high-density and laminar recordings. With a largely lissencephalic cortex, the common marmoset (Callithrix jacchus) is a promising alternative primate model for studying FEF microcircuitry. Putative homologies have been established with the macaque FEF on the basis of cytoarchitecture and connectivity; however, physiological investigation …

Discovery Of Novel Mechanisms Regulating Cancer Extravasation In The Chorioallantoic Membrane Model, Yohan Kim

Electronic Thesis and Dissertation Repository

Cancer metastasis is a multistep process that begins with the invasion of tumour cells into the stroma and migration towards the blood vessels. Tumour cells that have entered the bloodstream must then survive and leave by a process known as extravasation. Finally, extravasated cells proliferate and establish the secondary site in the metastatic cascade. Although extravasation encompasses key events during cancer cell invasion to aid in the development of effective treatments, an in vivo model that rapidly, reproducibly and economically recapitulates cancer cell extravasation is needed. Therefore, the objectives of my research were to 1) establish and validate an in …

High Frequency Oscillations Are Phase-Amplitude Coupled In Stress Induced Seizures Following Traumatic Brain Injury, Paul Jung

Electronic Thesis and Dissertation Repository

Traumatic Brain Injury (TBI) often leads to the development of epilepsy, especially with the occurrence of stressful events. Stressors increase the levels of corticotropin-releasing factor (CRF) in the amygdala, which can be damaged by the secondary effects of TBI. It is hypothesized that the activity of CRF receptor type 1 (CRFR₁) in the amygdala is altered post-TBI and supports the generation of epileptiform waves, namely high-frequency oscillations (HFOs). Sprague-Dawley rats were given a moderate TBI and in vivo recordings of the amygdala were taken during the administration of an acute tail pinch stressor. The stressor increased broadband activity …

Piezo1: Proteins For Mechanotransduction And Integration Of Endothelial Shear Stress & Intravascular Pressure, Juan Garcia Robledo M.D.

Electronic Thesis and Dissertation Repository

Piezo proteins are transmembrane ion channels, specialized in detecting mechanosensitive stimuli and transduce mechanical forces into biochemical signals. Piezo proteins research has helped understand physiological mechanisms, but the integrative role that Piezo1 plays in the regulation of the microvasculature has remained unstudied. Our main objective was to characterize ex vivo microvascular responses to the blockade of Piezo1 mechanotransduction in male (n=29) and female (n=24) Sprague-Dawley (SD) rats. Gracilis arterioles (GA) and middle cerebral arterioles (MCA) were harvested for ex-vivo vessel preparations. After vessel viability confirmation, every vessel was submitted to myogenic and flow challenges under control conditions and after Grammostola …

Comorbid Metabolic Syndrome And Prodromal Alzheimer's Disease In A Rat Model, Nadezda Ivanova

Electronic Thesis and Dissertation Repository

Metabolic syndrome (MetS), the development of which is associated with high-caloric Western diet intake, represents a risk factor for mild cognitive impairment (MCI) and Alzheimer’s disease (AD) and appears to contribute to AD progression when MetS and AD are comorbid. The interaction between AD and MetS might be through white matter inflammation, since white matter abnormalities and inflammation are important early events in the etiopathogenesis of both diseases. In these investigations, the effect of a high-caloric diet (HCD), to induce metabolic disturbances, on white matter neuroinflammation and cognitive function was investigated in a transgenic (TG) rat model of prodromal AD …

Performance Of Qct-Derived Scapula Finite Element Models In Predicting Local Displacements Using Digital Volume Correlation, Jonathan Kusins, Nikolas Knowles, Melissa Ryan, Enrico Dall'ara, Louis Ferreira

Bone and Joint Institute

© 2019 Subject-specific finite element models (FEMs)of the shoulder complex are commonly used to predict differences in internal load distribution due to injury, treatment or disease. However, these models rely on various underlying assumptions, and although experimental validation is warranted, it is difficult to obtain and often not performed. The goal of the current study was to quantify the accuracy of local displacements predicted by subject-specific QCT-based FEMs of the scapula, compared to experimental measurements obtained by combining digital volume correlation (DVC)and mechanical loading of cadaveric specimens within a microCT scanner. Four cadaveric specimens were loaded within a microCT scanner …

Effect Of Histatin- And Statherin-Derived Engineered Salivary Peptides On Streptococcus Mutans Adhesion And On Enamel Demineralization Provoked By Cariogenic Biofilms, Lina Maria Marin

Electronic Thesis and Dissertation Repository

Dental biofilm is formed onto dental surfaces covered by a layer of specific salivary proteins and peptides named acquired enamel pellicle (AEP). It was previously demonstrated that the statherin- and histatin-derived engineered salivary peptides DR9-DR9 and DR9-RR14 were able to reduce enamel demineralization and displayed antimicrobial activity against Streptococcus mutans, respectively. However, these studies were carried under experimental conditions that did not mimic caries development induced by biofilm and sucrose exposure, the most cariogenic dietary sugar. In this thesis we assessed the effect of the engineered salivary peptides on 1) the adherence of S. mutans to hydroxyapatite (HAp), and …

Exploring Current Topics And Trends In Anatomy Education: A Scoping Review, Alex Wolf

Electronic Thesis and Dissertation Repository

Within the field of health professional education, one finds that anatomy often presents students with a great deal of difficulty. The literature in this area is piecemeal and there is limited work available examining the whole of this topic. A scoping review was conducted to determine how students are taught anatomy across multiple disciplines (medicine, dentistry, rehabilitation sciences, and undergraduate education) and to assess for any notable differences between these populations. The results found that scholarship on anatomy instruction varies based on educational context, and medical students are the most frequently targeted student population. It also found that the use …

Quantifying The Outcomes Of A Virtual Reality (Vr)-Based Gamified Neck Rehabilitation, Shahan Salim

Electronic Thesis and Dissertation Repository

Neck pain is a major global public health concern and adds a significant financial burden to both the healthcare system as well as people suffering from it. Additionally, it presents measurement and evaluation challenges for clinicians as well as adherence challenges and treatment barriers for the patients. We have developed a virtual reality (VR)-based video game that can be used to capture outcomes that may aid in the assessment and treatment of neck pain. We investigated: (i) performance metrics of overall accuracy, accuracy based on movement difficulty, duration, and total envelope of movement; (ii) stability across sessions; (iii) accuracy across …

Functional Magnetic Resonance Spectroscopy In First-Episode Schizophrenia: Measuring Glutamate And Glutathione Dynamics At 7-Tesla, Peter Jeon

Electronic Thesis and Dissertation Repository

Schizophrenia is a neuropsychiatric illness without known etiology or cure. Current efforts for symptom treatment still seem to leave a large portion of affected individuals without proper symptom management, with those experiencing symptom relief still having to wrestle with potential side-effects from medication trials. There has been growing evidence suggesting that glutamate and glutathione abnormalities hold major roles in development and manifestation of schizophrenia symptoms.

Magnetic resonance spectroscopy (MRS) provides a non-invasive means to observe in-vivo brain chemistry, including glutamate and glutathione. By adding a functional component to an MRS paradigm (fMRS), such as the color-word Stroop task, it is …

The Role Of The Tau N-Terminal Phosphatase-Activating Domain And Phosphorylation At Thr175 In The Formation Of Tau Cytoplasmic Inclusions, Matthew A. Hintermayer

Electronic Thesis and Dissertation Repository

Cytoplasmic inclusions and fibrils of the microtubule-associated protein tau (tau protein) are a key neuropathological hallmark in tauopathies, including Alzheimer’s disease, chronic traumatic encephalopathy, and amyotrophic lateral sclerosis with cognitive impairment. Previous research has demonstrated that the phosphorylation of tau protein at Thr¹⁷⁵ is sufficient for the initiation of fibril formation both in vitro and in vivo. Here we use mutated tau protein constructs to demonstrate that phosphorylation at Thr¹⁷⁵ results in the aberrant exposure of an N-terminal phosphatase-activating domain (PAD). The tau PAD interacts with protein phosphatase 1 (PP1) leading to the activation of glycogen synthase …

Maternal Nicotine Exposure Induces Congenital Heart Defects In The Offspring Of Mice, Elizabeth Greco

Electronic Thesis and Dissertation Repository

Congenital heart defects are the most prevalent birth defect, and maternal cigarette smoking is a known risk factor. Nicotine replacement therapies are recommended to pregnant women who smoke to aid in smoking cessation, as this alternative is thought to be much safer compared to cigarette smoking. However, these products contain nicotine, and the safety of nicotine on the developing heart is not well known. In this thesis, a mouse model was used to test the hypothesis that maternal nicotine exposure (MNE) during pregnancy leads to congenital heart defects and coronary artery defects in the offspring of mice. MNE resulted in …

Health Policy And Social Change: Women’S Advocacy Groups And Narrative Mobilization, Jill Moffatt

Electronic Thesis and Dissertation Repository

The goal of this study is to systematically investigate the mobilization of co-created (storyteller and story-gatherer) narratives for policy and social change. A case study format investigated the mobilization of narratives by a women’s health organization in London, Ontario. Semi-structured interviews resulted in transcripts from key actors. These transcripts were thematically coded and analyzed. All interview participants emphasized that from their perspective the organization did influence health policy or social change through their narrative use. Specific policy change examples were provided by participants, and social change was subjectively recognized as realized through the creation of awareness and affirmed through audience …

A National Survey Of Resources To Address Sepsis In Children In Tertiary Care Centers In Nigeria., Odiraa C Nwankwor, Brianna Mckelvie, Meg Frizzola, Krystal Hunter, Halima S Kabara, Abiola Oduwole, Tagbo Oguonu, Niranjan Kissoon

Paediatrics Publications

Background:
Infections leading to sepsis are major contributors to mortality and morbidity in children world-wide. Determining the capacity of pediatric hospitals in Nigeria to manage sepsis establishes an important baseline for quality-improvement interventions and resource allocations.

Objectives:
To assess the availability and functionality of resources and manpower for early detection and prompt management of sepsis in children at tertiary pediatric centers in Nigeria.

Methods:
This was an online survey of tertiary pediatric hospitals in Nigeria using a modified survey tool designed by the World Federation of Pediatric Intensive and Critical Care Societies (WFPICCS). The survey addressed all aspects of pediatric …

Twelve Tips For Enhancing Student Engagement., Harm Peters, Marko Zdravkovic, Manuel João Costa, Antonio Celenza, Kulsoom Ghias, Debra Klamen, Liz Mossop, Michael Rieder, Vishna Devi Nadarajah, Danai Wangsaturaka, Martin Wohlin, Margot Weggemans

Paediatrics Publications

Student engagement refers to a broad range of activities where students participate in management, education, research, and community activities within their institutions. It is a mutually beneficial collaborative approach between students and their institutions. This article provides practical advice for the implementation or further development of student engagement at medical, dental, and veterinary schools. The tips provided are based on the experiences of a group of universities recently recognized for best practice in student engagement, and are supported by evidence from the literature. The tips cover overarching themes which include the creation of an institutional culture and formal framework for …

Lateral Compartment Contact Pressures Do Not Increase After Lateral Extra-Articular Tenodesis And Subsequent Subtotal Meniscectomy, Tomoyuki Shimakawa, Timothy A. Burkhart, Cynthia E. Dunning, Ryan M. Degen, Alan M. Getgood

Bone and Joint Institute

© The Author(s) 2019. Background: Modified Lemaire lateral extra-articular tenodesis (LET) has been proposed as a method of addressing persistent anterolateral rotatory laxity after anterior cruciate ligament (ACL) reconstruction (ACLR). However, concerns remain regarding the potential for increasing lateral compartment contact pressures. Purpose: To investigate changes in tibiofemoral joint contact pressures after isolated ACLR and combined ACLR plus LET with varying states of a lateral meniscal injury. Study Design: Controlled laboratory study. Methods: Eight fresh-frozen cadaveric knee specimens (mean age, 60.0 ± 3.4 years) were utilized for this study, with specimens potted and loaded on a materials testing machine. A …

Δ9-Tetrahydrocannabinol Leads To Endoplasmic Reticulum Stress And Mitochondrial Dysfunction In Human Bewo Trophoblasts., Tina Lojpur, Zachary Easton, Sergio Raez-Villanueva, Steven Laviolette, Alison C Holloway, Daniel B Hardy

Physiology and Pharmacology Publications

While studies have demonstrated that the main psychoactive component of cannabis, Δ9-tetrahydrocannabinol (Δ9-THC) alone induces placental insufficiency and fetal growth restriction, the underlying mechanisms remain elusive. Given that both (i) endoplasmic reticulum (ER) stress in pregnancy and (ii) gestational exposure to Δ9-THC leads to placental deficiency, we hypothesized that Δ9-THC may directly induce placental ER stress, influencing trophoblast gene expression and mitochondrial function. BeWo human trophoblast cells treated with Δ9-THC (3-30 μM) led to a dose-dependent increase in all ER stress markers and CHOP; these effects could be blocked with CB1R/CB2R antagonists. Moreover, expression of ER stress-sensitive genes ERRγ, VEGFA, …

Towards On-Line Plan Adaptation Of Unified Intensity-Modulated Arc Therapy Using A Fast-Direct Aperture Optimization Algorithm, Michael Macfarlane

Electronic Thesis and Dissertation Repository

External beam radiotherapy (EBRT) plays a vital role in the treatment of cancer, with close to half of all cancer patients receiving EBRT at some point over their course of treatment. Although EBRT is a well-established form of treatment, there are a number of ways in which EBRT could still be improved in terms of quality and efficiency for treatment planning and radiation dose delivery. This thesis reports a series of improvements made to EBRT.

First, we developed and evaluated a new treatment planning technique called unified intensity-modulated arc therapy (UIMAT) which combines the optimization and delivery of rotational volumetric …

Haptics-Enabled, Gpu Augmented Surgical Simulation Platform For Glenoid Reaming, Vlad Popa

Electronic Thesis and Dissertation Repository

Surgical simulators are technological platforms that provide virtual substitutes to the current cadaver-based medical training models. The advantages of exposure to these devices have been thoroughly studied, with enhanced surgical proficiency being one of the assets gained after extensive use. While simulators have already penetrated numerous medical domains, the field of orthopedics remains stagnant despite a demand for the ability to practice uncommon surgeries, such as total shoulder arthroplasty (TSA). Here we extrapolate the algorithms of an inhouse software engine revolving around glenoid reaming, a critical step of TSA. The project’s purpose is to provide efficient techniques for future simulators, …

Potential Role Of Extracellular Atp Released By Bacteria In Bladder Infection And Contractility, Behnam Abbasian

Electronic Thesis and Dissertation Repository

Urgency urinary incontinence (UUI), the result of conditions such as overactive bladder (OAB), could potentially be influenced by both commensal and urinary tract infection-associated bacteria. The sensing of bladder filling involves interplay between various parts of the nervous system eventually resulting in contraction of the detrusor muscle during micturition. Here we model host responses to various urogenital bacteria, firstly by using urothelial bladder cell lines and then with myofibroblast contraction assays. To measure responses, we examined calcium influx, gene expression and alpha smooth muscle actin deposition assays. We found that organisms such as Escherichia coli IA2 and Gardnerella vaginalis ATCC …

Hiv-1 Group M Subtype Fitness, Disease Progression, And Entry Efficiency, Colin M. Venner

Electronic Thesis and Dissertation Repository

Human immunodeficiency virus type 1 (HIV-1) emerged in the human population shortly after the turn of the 19th century. Distribution of HIV-1 across the globe over the past 30–35 years can be traced to founder events with primordial HIV strains from sub-Saharan Africa. Even considering the burden of HIV in Africa, our knowledge of HIV-1 disease is still largely limited to subtype B HIV-1, a strain responsible for 3 million infections in North America and Europe as compared to the 33 million that are infected with HIV-1 subtypes A, C, D, and circulating and unique recombinant forms.

This dissertation analyzes …

Mass Spectrometry-Based Proteomics Analysis Of Bioactive Proteins In Emd That Modulate Adhesion Of Gingival Fibroblast To Improve Bio-Integration Of Dental Implants, David Zuanazzi Machado Jr

Electronic Thesis and Dissertation Repository

Titanium implants are used in dental practice to replace damaged or lost teeth. The implant needs to integrate with the surrounding gingiva to protect it against bacterial invasion that leads to implant loss. The biointegration is dependent on the implant surface that interacts with proteins from biological fluids to modulate tissues response. Tailoring the surface with specific proteins from the enamel matrix derivative (EMD) would be beneficial to improve the implant-gingiva interface since EMD can affect various cells including gingival fibroblasts. A surface-affinity approach using three different titanium surfaces and saliva was utilized as a model in combination with tandem …

Crf Mediates Stress-Induced Pathophysiological High-Frequency Oscillations In Traumatic Brain Injury, Chakravarthi Narla, Paul S. Jung, Francisco Bautista Cruz, Michelle Everest, Julio Martinez-Trujillo, Michael O. Poulter

Physiology and Pharmacology Publications

Copyright © 2019 Narla et al. It is not known why there is increased risk to have seizures with increased anxiety and stress after traumatic brain injury (TBI). Stressors cause the release of corticotropin-releasing factor (CRF) both from the hypothalamic pituitary adrenal (HPA) axis and from CNS neurons located in the central amygdala and GABAergic interneurons. We have previously shown that CRF signaling is plastic, becoming excitatory instead of inhibitory after the kindling model of epilepsy. Here, using Sprague Dawley rats we have found that CRF signaling increased excitability after TBI. Following TBI, CRF type 1 receptor (CRFR1)-mediated activity caused …

Inhibition Of Pannexin 1 Reduces The Tumorigenic Properties Of Human Melanoma Cells, Taylor J. Freeman, Samar Sayedyahossein, Rafael E. Sanchez-Pupo, Brooke O'Donnell, Kenneth Huang, Zameena Lakhani, Daniel Nouri-Nejad, Kevin J. Barr, Luke Harland, Steven Latosinsky, Aaron Grant, Lina Dagnino, Silvia Penuela

Anatomy and Cell Biology Publications

Pannexin 1 (PANX1) is a channel-forming glycoprotein expressed in many tissues including the skin. PANX1 channels allow the passage of ions and molecules up to 1 kDa, including ATP and other metabolites. In this study, we show that PANX1 is highly expressed in human melanoma tumors at all stages of disease progression, as well as in patient-derived cells and established melanoma cell lines. Reducing PANX1 protein levels using shRNA or inhibiting channel function with the channel blockers, carbenoxolone (CBX) and probenecid (PBN), significantly decreased cell growth and migration, and increased melanin production in A375-P and A375-MA2 cell lines. Further, treatment …

A Novel Technique For Measurement Of Orthodontic Mini-Implant Stability Using The Osstell Isq Device, Yara K. Hosein, S. Jeffrey Dixon, Amin S. Rizkalla, Ali Tassi

Bone and Joint Institute

© 2019 by The EH Angle Education and Research Foundation, Inc. Objectives: To develop and validate a method for application of the Osstell ISQ device in the assessment of mini-implant stability. Materials and Methods: An adaptor was developed for attachment of Osstell's SmartPeg onto a variety of orthodontic mini-implants. For validation of the adaptor, Benefit mini-implants were inserted into bone blocks that mimicked different stability conditions. The Osstell device was used to assess mini-implant stability with the adaptor (test measurement) and conventional SmartPeg attachment (gold-standard measurement). Implant stability quotient (ISQ) values were assessed for agreement, repeatability, and reproducibility. Results: Strong …