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Medical Sciences 4300: London-Middlesex Suicide Prevention Council, Harshith Bhaskar, Adnan Husein, Ramin Javaheri-Poya, Sabrina Jetly, Christopher Nguyen, Serena Tejpar

Community Engaged Learning Final Projects

Suicide is an issue that affects people of all backgrounds, and takes the lives of many individuals every year. The London-Middlesex Suicide Prevention Council (LMSPC), an organization established in 1990, seeks to provide suicide prevention training to members of the community. They seek to engage community members in prevention and intervention by recognizing warning signs that may exist among the London-Middlesex region. The three main programs that strive to deliver these skills are ASIST, ASK, and safeTALK, each with a slightly different focus. LMSPC’s current goal is to increase access to these services through external grants and potential partnerships. Our …

Hepcidin-Mediated Iron Regulation In P19 Cells Is Detectable By Mri, Kobra Alizadeh Pourbouyeh

Electronic Thesis and Dissertation Repository

Magnetic resonance imaging (MRI) can be used to track cellular activities in the body using iron-based contrast agents. However, intrinsic cellular iron handling mechanisms may also influence the detection of magnetic resonance (MR) contrast. For instance, inflammation involves downregulation of iron export in macrophages by the hormone hepcidin, due to degradation of the iron export protein, ferroportin (Fpn). We examined the effect of hepcidin on iron regulation and MR transverse relaxation rates in multi-potent P19 cells, which display high iron export activity, similar to macrophages. In response to varying conditions of iron supplementation, our results showed similar Fpn expression in …

Neuronal Correlates For Neuroendocrine Habituation To Repeated Stress, Sara Matovic

Electronic Thesis and Dissertation Repository

One way that the body actively responds to an impending stressor is by increasing systemic glucocorticoids through the activation of the hypothalamic-pituitary-adrenal (HPA) axis. While it is essential for short-term adaptation to stress, the sustained activation of the HPA axis during chronic stress can be detrimental and is linked to stress-related psychiatric conditions such as anxiety and depression. Therefore, it is important that the HPA axis adapts, or habituates, during chronic stress to minimize the negative consequences. Corticotropin releasing hormone (CRH) neurons in the paraventricular nucleus of the hypothalamus (PVN) function to assimilate incoming information from the stress circuitry and …

Evaluating Small Airways Disease In Asthma And Copd Using The Forced Oscillation Technique And Magnetic Resonance Imaging, Heather M. Young

Electronic Thesis and Dissertation Repository

Obstructive lung disease, including asthma and chronic obstructive pulmonary disease (COPD), is characterized by heterogeneous ventilation. Unfortunately, the underlying structure-function relationships and the relationships between measurements of heterogeneity and patient quality-of-life in obstructive lung disease are not well understood. Hyperpolarized noble gas MRI is used to visualize and quantify ventilation distribution and the forced oscillation technique (FOT) applies a multi-frequency pressure oscillation at the mouth to measure respiratory impedance to airflow (including resistance and reactance). My objective was to use FOT, ventilation MRI and computational airway tree modeling to better understand ventilation heterogeneity in asthma and COPD. FOT-measured respiratory system …

Higher And Lower Order Factor Analyses Of The Temperament In Middle Childhood Questionnaire., Yuliya Kotelnikova, Thomas M Olino, Daniel N Klein, Sarah V M Mackrell, Elizabeth P Hayden

Brain and Mind Institute Researchers' Publications

The Temperament in Middle Childhood Questionnaire (TMCQ) is a widely used parent-report measure of temperament. However, neither its lower nor higher order structures has been tested via a bottom-up, empirically based approach. We conducted higher and lower order exploratory factor analyses (EFAs) of the TMCQ in a large ( N = 654) sample of 9-year-olds. Item-level EFAs identified 92 items as suitable (i.e., with loadings ≥.40) for constructing lower order factors, only half of which resembled a TMCQ scale posited by the measure's authors. Higher order EFAs of the lower order factors showed that a three-factor structure (Impulsivity/Negative Affectivity, Negative …

Multiparametric Mri Changes Persist Beyond Recovery In Concussed Adolescent Hockey Players, Kathryn Y. Manning, Amy Schranz, Robert Bartha, Gregory A. Dekaban, Christy Barreira, Arthur Brown, Lisa Fischer, Kevin Asem, Timothy J. Doherty, Douglas D. Fraser, Jeff Holmes, Ravi S. Menon

BrainsCAN Publications

Objective: To determine whether multiparametric MRI data can provide insight into the acute and long-lasting neuronal sequelae after a concussion in adolescent athletes.

Methods: Players were recruited from Bantam hockey leagues in which body checking is first introduced (male, age 11–14 years). Clinical measures, diffusion metrics, resting-state network and region-to-region functional connectivity patterns, and magnetic resonance spectroscopy absolute metabolite concentrations were analyzed from an independent, age-matched control group of hockey players (n 5 26) and longitudinally in concussed athletes within 24 to 72 hours (n 5 17) and 3 months (n 5 14) after a diagnosed concussion.

Results: There were …

A Longitudinal Study Of Tumour Metabolism Using Hyperpolarized Carbon-13 Magnetic Resonance Spectroscopic Imaging In A Preclinical Model Of Glioma, Heeseung Lim

Electronic Thesis and Dissertation Repository

Glioma is the most common and aggressive primary malignant brain tumour. Glioma is typically treated with surgery followed by radio/chemotherapy. Even with aggressive treatment, median survival time is expected to be ~12 to 15 months. Reoccurrence of glioma is almost inevitable, further threatening the well-being of patients who have already endured rigorous treatment. Therefore, it is paramount to choose the most effective therapy and to accurately determine outcome as early as possible to provide optimum end-of-life care. Tumours alter their metabolism in response to increasing energy demands, mainly through increased glycolysis and accompanying lactate production. This increases production of other …

Characterization Of An Orthotopic Rat Model Of Glioblastoma Using Multiparametric Magnetic Resonance Imaging And Bioluminescence Imaging, Trung Le

Electronic Thesis and Dissertation Repository

Glioblastoma multiforme (GBM) is a lethal and incurable disease. The C6 rat model of GBM shares several similarities to human GBM and longitudinal non-invasive imaging may allow tumour features to be studied. In this thesis, a multimodality imaging framework, consisting of bioluminescence imaging (BLI) and multiparametric magnetic resonance imaging (mpMRI), was applied to the C6 rat model to characterize the growth of orthotopic tumours. BLI signal, a measure of cell viability, tended to increase and then decrease in the majority of animals, whereas tumour volume (from MRI) continually increased. Cellular viability and tumour volume did not correlate across all days, …

Vocabulary Learning Benefits From Rem After Slow-Wave Sleep., Laura J Batterink, Carmen E Westerberg, Ken A Paller

Brain and Mind Institute Researchers' Publications

Memory reactivation during slow-wave sleep (SWS) influences the consolidation of recently acquired knowledge. This reactivation occurs spontaneously during sleep but can also be triggered by presenting learning-related cues, a technique known as targeted memory reactivation (TMR). Here we examined whether TMR can improve vocabulary learning. Participants learned the meanings of 60 novel words. Auditory cues for half the words were subsequently presented during SWS in an afternoon nap. Memory performance for cued versus uncued words did not differ at the group level but was systematically influenced by REM sleep duration. Participants who obtained relatively greater amounts of REM showed a …

Functional Magnetic Resonance Imaging As An Assessment Tool In Critically Ill Patients, Loretta Norton

Electronic Thesis and Dissertation Repository

Little is known about whether residual cognitive function occurs in the earliest stages of brain injury. The overarching goal of the work presented in this dissertation was to elucidate the role of functional neuroimaging in assessing brain activity in critically ill patients. The overall objective was addressed in the following four empirical chapters: In Chapter 2, three versions of a hierarchically-designed auditory task were developed and their ability to detect various levels of auditory language processing was assessed in individual healthy participants. The same procedure was then applied in two acutely comatose patients. In Chapter 3, a hierarchical auditory task …

Electrospun Collagen Nanofibers For Tissue Engineering, Nisha Sharma

Electronic Thesis and Dissertation Repository

Design and fabrication of the scaffold is an important part of the tissue engineering process. Nanofibrous scaffolds based on proteins are gaining increasing acceptance due to its structural similarity to the extracellular matrix. Making use of the electrospinning technique, rat tail collagen type I nanofibers were produced using a collagen in hexafluoroisopropanol (HFIP) solution. In addition to optimizing the electrospinning process parameters, the effect of humidity on fiber morphology and diameter was investigated for fiber size control for particular tissue engineering applications. A generalized humidity effect on polymer fiber diameter of the polymer solution electrospinning process was developed. The as …

Using Computed Tomography Perfusion To Evaluate The Blood-Brain-Barrier And Blood-Tumor-Barrier Response Following Focused Ultrasound Sonication With Microbubble Administration, Hassaan Ahmed

Electronic Thesis and Dissertation Repository

The blood-brain-barrier (BBB) is the single most limiting factor in the delivery of neurotherapeutics into the brain. Focused ultrasound sonication combined with intravenous microbubble administration (FUSwMB) is a novel technique that can transiently disrupt the BBB, with minimal vascular or tissue damage, allowing for localized drug delivery over the targeted region. The goals of this thesis are to: 1) use computed tomography (CT) perfusion to measure the permeability surface area product (PS) following USwMB in normal rabbits with an intact BBB, and 2) to evaluate the blood-tumor-barrier (BTB) PS response following FUSwMB in a C6 rat glioma model.

The Design, Fabrication, And Characterization Of Nanoparticle-Protein Interactions For Theranostic Applications, Wai Hei Tse

Electronic Thesis and Dissertation Repository

Theranostics, a combination of therapeutics and diagnostics, spans a spectrum of research areas to provide new opportunities in developing new healthcare technologies and medicine at affordable prices. Through employing a personalized medicine approach, biotechnology can be tailored to the needs of an individual. Applications of theranostics include drug delivery carriers capable of sustained drug release and targeted delivery, biosensors with high sensitivity and selectivity, and diagnostic relevant entities that can be incorporated into the former technologies. Nanotechnology provides a suitable foundation for theranostics to build upon due to material-based properties; magnetism, biocompatibility, and quantum effects to name a few. Purpose …

Cooperation Not Competition: Bihemispheric Tdcs And Fmri Show Role For Ipsilateral Hemisphere In Motor Learning, Sheena Waters, Tobias Wiestler, Jörn Diedrichsen

Brain and Mind Institute Researchers' Publications

What is the role of ipsilateral motor and premotor areas in motor learning? One view is that ipsilateral activity suppresses contralateral motor cortex and, accordingly, that inhibiting ipsilateral regions can improve motor learning. Alternatively, the ipsilateral motor cortex may play an active role in the control and/or learning of unilateral hand movements. We approached this question by applying double-blind bihemispheric transcranial direct current stimulation (tDCS) over both contralateral and ipsilateral motor cortex in a between-group design during 4 d of unimanual explicit sequence training in human participants. Independently of whether the anode was placed over contralateral or ipsilateral motor cortex, …

Maternal Nicotine Exposure Leads To Decreased Cardiac Protein Disulfide Isomerase And Impaired Mitochondrial Function In Male Rat Offspring., Nicole G Barra, Maria Lisyansky, Taylor A Vanduzer, Sandeep Raha, Alison C Holloway, Daniel B Hardy

Physiology and Pharmacology Publications

Smoking throughout pregnancy can lead to complications during gestation, parturition and neonatal development. Thus, nicotine replacement therapies are a popular alternative thought to be safer than cigarettes. However, recent studies in rodents suggest that fetal and neonatal nicotine exposure alone results in cardiac dysfunction and high blood pressure. While it is well known that perinatal nicotine exposure causes increased congenital abnormalities, the mechanisms underlying longer-term deficits in cardiac function are not completely understood. Recently, our laboratory demonstrated that nicotine impairs placental protein disulfide isomerase (PDI) triggering an increase in endoplasmic reticulum stress, leading us to hypothesize that this may also …

Increased Incidence Of Non-Alcoholic Fatty Liver Disease In Male Rat Offspring Exposed To Fluoxetine During Fetal And Neonatal Life Involves The Nlrp3 Inflammasome And Augmented De Novo Hepatic Lipogenesis., Nicole E De Long, Daniel B Hardy, Noelle Ma, Alison C Holloway

Physiology and Pharmacology Publications

Up to 10% of women take selective serotonin reuptake inhibitors (SSRI) during pregnancy. Children exposed to SSRIs in utero have an increased risk of being overweight suggesting that fetal exposure to SSRIs can cause permanent metabolic changes. We have previously shown in rats that fetal and neonatal exposure to the SSRI antidepressant fluoxetine results in metabolic perturbations including increased hepatic triglyceride content; a hallmark of non-alcoholic fatty liver disease (NAFLD). Therefore, the aim of this study was to identify the mechanism(s) underlying the fluoxetine-induced increase in intrahepatic triglyceride content. Female nulliparous Wistar rats were given vehicle or fluoxetine (10 mg/kg/day) …

3d Ultrasound In The Management Of Post Hemorrhagic Ventricle Dilatation, Jessica Kishimoto

Electronic Thesis and Dissertation Repository

Enlargement of the cerebral ventricles is relatively common among extremely preterm neonates born before 28 weeks gestational age. One common cause of ventricle dilatation is post hemorrhagic ventricle dilatation following a bleed in the cerebral ventricles. While many neonates with PHVD will have spontaneous resolution of the condition, severe, persistent PHVD is associated with a greater risk of brain injury and morbidity later in life and left untreated can cause death. The current clinical management strategy consists of daily measurements of head circumference and qualitative interpretation of two-dimensional US images to detect ventricular enlargement and monitoring vital signs for indications …

Rapid Statistical Learning Supporting Word Extraction From Continuous Speech., Laura J Batterink

Brain and Mind Institute Researchers' Publications

The identification of words in continuous speech, known as speech segmentation, is a critical early step in language acquisition. This process is partially supported by statistical learning, the ability to extract patterns from the environment. Given that speech segmentation represents a potential bottleneck for language acquisition, patterns in speech may be extracted very rapidly, without extensive exposure. This hypothesis was examined by exposing participants to continuous speech streams composed of novel repeating nonsense words. Learning was measured on-line using a reaction time task. After merely one exposure to an embedded novel word, learners demonstrated significant learning effects, as revealed by …

Comparison Of Modified Two-Point Dixon And Chemical Shift Encoded Mri Water-Fat Separation Methods For Fetal Fat Quantification: Compare Water-Fat Methods For Fetal Fat, Stephanie A. Giza, Michael R. Miller, Prasiddha Parthasarathy, Barbra De Vrijer, Charles A. Mckenzie

Medical Biophysics Publications

This is the peer reviewed version of the following article: [Comparison of modified two-point dixon and chemical shift encoded MRI water-fat separation methods for fetal fat quantification: Compare Water-Fat Methods for Fetal Fat. Journal of Magnetic Resonance Imaging 48, 1 p274-282 (2018)], which has been published in final form at https://doi.org/10.1002/jmri.25929. This article may be used for non-commercial purposes in accordance with Wiley Terms and Conditions for Use of Self-Archived Versions: https://authorservices.wiley.com/author-resources/Journal-Authors/licensing/self-archiving.html#3.

Maternal Undernutrition And Long-Term Effects On Hepatic Function, Daniel B. Hardy

Physiology and Pharmacology Publications

Undernutrition in utero, regardless of the source, can impair proper liver development leading to long-term metabolic dysfunction. Understanding the molecular mechanisms underlying how nutritional deficits during perinatal life lead to permanent alterations in hepatic gene expression will provide better therapeutic strategies to alleviate the undernourished liver in postnatal life. This chapter addresses the different experimental models of undernutrition in utero, and highlights the direct and indirect mechanisms involved leading to metabolic diseases in the liver. These include hypoxia, oxidative stress, epigenetic alterations, and endoplasmic reticulum (ER) stress. In addition, promising perinatal nutritional and pharmaceutical interventions are highlighted which …

In Vivo Magnetic Resonance Imaging Morphometry Measurements Of Pulmonary Airspace Enlargement, Eric J. Lessard

Electronic Thesis and Dissertation Repository

Diffusion-weighted magnetic resonance imaging (MRI) provides unparalleled information and measurements of lung structure and function without the burden of ionizing radiation. In particular, diffusion-weighted MRI provides estimates of airspace enlargement, which is a hallmark characteristic of emphysema. MRI provides a way to measure in vivo mean-linear-intercept (L_m) and this is a promising measurement for clinical evaluation of disease progression in patients with Alpha-1 Antitrypsin Deficiency (AATD) in which airspace enlargement begins early in life. As such, our objective was to evaluate MRI measurements of airspace enlargement in AATD patients and compare these measurements to ex-smokers with chronic obstructive …

Automated Vascular Smooth Muscle Segmentation, Reconstruction, Classification And Simulation On Whole-Slide Histology, Yiwen Xu

Electronic Thesis and Dissertation Repository

Histology of the microvasculature depicts detailed characteristics relevant to tissue perfusion. One important histologic feature is the smooth muscle component of the microvessel wall, which is responsible for controlling vessel caliber. Abnormalities can cause disease and organ failure, as seen in hypertensive retinopathy, diabetic ischemia, Alzheimer’s disease and improper cardiovascular development. However, assessments of smooth muscle cell content are conventionally performed on selected fields of view on 2D sections, which may lead to measurement bias. We have developed a software platform for automated (1) 3D vascular reconstruction, (2) detection and segmentation of muscularized microvessels, (3) classification of vascular subtypes, and …

Tools For Improving High-Dose-Rate Prostate Cancer Brachytherapy Using Three-Dimensional Ultrasound And Magnetic Resonance Imaging, William T. Hrinivich

Electronic Thesis and Dissertation Repository

High-dose-rate brachytherapy (HDR-BT) is an interstitial technique for the treatment of intermediate and high-risk localized prostate cancer that involves placement of a radiation source directly inside the prostate using needles. Dose-escalated whole-gland treatments have led to improvements in survival, and tumour-targeted treatments may offer future improvements in therapeutic ratio. The efficacy of tumour-targeted HDR-BT depends on imaging tools to enable accurate dose delivery to prostate sub-volumes. This thesis is focused on implementing ultrasound tools to improve HDR-BT needle localization accuracy and efficiency, and evaluating dynamic contrast enhanced magnetic resonance imaging (DCE-MRI) for tumour localization.

First, we implemented a device enabling …

Coordinated Pluralism As A Means To Facilitate Integrative Taxonomies Of Cognition, Jacqueline Anne Sullivan

Brain and Mind Institute Researchers' Publications

© 2017 Informa UK Limited, trading as Taylor & Francis Group. The past decade has witnessed a growing awareness of conceptual and methodological hurdles within psychology and neuroscience that must be addressed for taxonomic and explanatory progress in understanding psychological functions to be possible. In this paper, I evaluate several recent knowledge-building initiatives aimed at overcoming these obstacles. I argue that while each initiative offers important insights about how to facilitate taxonomic and explanatory progress in psychology and neuroscience, only a “coordinated pluralism” that incorporates positive aspects of each initiative will have the potential for success.

Online Neural Monitoring Of Statistical Learning., Laura J Batterink, Ken A Paller

Brain and Mind Institute Researchers' Publications

The extraction of patterns in the environment plays a critical role in many types of human learning, from motor skills to language acquisition. This process is known as statistical learning. Here we propose that statistical learning has two dissociable components: (1) perceptual binding of individual stimulus units into integrated composites and (2) storing those integrated representations for later use. Statistical learning is typically assessed using post-learning tasks, such that the two components are conflated. Our goal was to characterize the online perceptual component of statistical learning. Participants were exposed to a structured stream of repeating trisyllabic nonsense words and a …

Bk Channels Mediate Synaptic Plasticity Underlying Habituation In Rats., Tariq Zaman, Cleusa De Oliveira, Mahabba Smoka, Chakravarthi Narla, Michael O Poulter, Susanne Schmid

Brain and Mind Institute Researchers' Publications

Habituation is a basic form of implicit learning and represents a sensory filter that is disrupted in autism, schizophrenia, and several other mental disorders. Despite extensive research in the past decades on habituation of startle and other escape responses, the underlying neural mechanisms are still not fully understood. There is evidence from previous studies indicating that BK channels might play a critical role in habituation. We here used a wide array of approaches to test this hypothesis. We show that BK channel activation and subsequent phosphorylation of these channels are essential for synaptic depression presumably underlying startle habituation in rats, …

G Protein-Coupled Kiss1 Receptor Is Overexpressed In Triple Negative Breast Cancer And Promotes Drug Resistance., Alexandra Blake, Magdalena Dragan, Rommel G Tirona, Daniel B Hardy, Muriel Brackstone, Alan B Tuck, Andy V Babwah, Moshmi Bhattacharya

Physiology and Pharmacology Publications

Triple-negative breast cancer (TNBC) lacks the expression of estrogen receptor α, progesterone receptor and human epidermal growth factor receptor 2 (HER2). TNBC patients lack targeted therapies, as they fail to respond to endocrine and anti-HER2 therapy. Prognosis for this aggressive cancer subtype is poor and survival is limited due to the development of resistance to available chemotherapies and resultant metastases. The mechanisms regulating tumor resistance are poorly understood. Here we demonstrate that the G protein-coupled kisspeptin receptor (KISS1R) promotes drug resistance in TNBC cells. KISS1R binds kisspeptins, peptide products of the KISS1 gene and in numerous cancers, this signaling pathway …

Therapeutic Application Of Carbon Monoxide In Acute Limb Compartment Syndrome, Aurelia Bihari

Electronic Thesis and Dissertation Repository

Acute limb compartment syndrome (CS), a devastating complication of musculoskeletal trauma, develops in response to elevation of the pressure within a closed osseofascial compartment, producing muscle- and limb-threatening ischemia. Full decompression of all involved compartments by fasciotomy is the current gold-standard therapy, but it must be performed within a surgical window of 6-8 hours, before tissue damage becomes permanent.

Carbon monoxide (CO), a byproduct of heme metabolism, has been shown protective in ischemia. While inhalation of CO leads to elevation of carboxyhemoglobin (COHb), recent development of transitional metal carbonyls, CO-releasing molecules (CO-RMs), particularly the water-soluble CORM-3, delivers CO in a …

Sleep-Based Memory Processing Facilitates Grammatical Generalization: Evidence From Targeted Memory Reactivation., Laura J Batterink, Ken A Paller

Brain and Mind Institute Researchers' Publications

Generalization-the ability to abstract regularities from specific examples and apply them to novel instances-is an essential component of language acquisition. Generalization not only depends on exposure to input during wake, but may also improve offline during sleep. Here we examined whether targeted memory reactivation during sleep can influence grammatical generalization. Participants gradually acquired the grammatical rules of an artificial language through an interactive learning procedure. Then, phrases from the language (experimental group) or stimuli from an unrelated task (control group) were covertly presented during an afternoon nap. Compared to control participants, participants re-exposed to the language during sleep showed larger …

Developments In Pet-Mri For Radiotherapy Planning Applications, John Christian Patrick

Electronic Thesis and Dissertation Repository

The hybridization of magnetic resonance imaging (MRI) and positron emission tomography (PET) provides the benefit of soft-tissue contrast and specific molecular information in a simultaneous acquisition. The applications of PET-MRI in radiotherapy are only starting to be realised. However, quantitative accuracy of PET relies on accurate attenuation correction (AC) of, not only the patient anatomy but also MRI hardware and current methods, which are prone to artefacts caused by dense materials. Quantitative accuracy of PET also relies on full characterization of patient motion during the scan. The simultaneity of PET-MRI makes it especially suited for motion correction. However, quality assurance …