Medicine and Health Sciences Commons^™

Nicotine Receptors Mediating Sensorimotor Gating And Its Enhancement By Systemic Nicotine., Farena Pinnock, Daniel Bosch, Tyler Brown, Nadine Simons, John R Yeomans, Cleusa Deoliveira, Susanne Schmid

Brain and Mind Institute Researchers' Publications

Prepulse inhibition (PPI) of startle occurs when intensity stimuli precede stronger startle-inducing stimuli by 10-1000 ms. PPI deficits are found in individuals with schizophrenia and other psychiatric disorders, and they correlate with other cognitive impairments. Animal research and clinical studies have demonstrated that both PPI and cognitive function can be enhanced by nicotine. PPI has been shown to be mediated, at least in part, by mesopontine cholinergic neurons that project to pontine startle neurons and activate muscarinic and potentially nicotine receptors (nAChRs). The subtypes and anatomical location of nAChRs involved in mediating and modulating PPI remain unresolved. We tested the …

Prolonged In Vivo Retention Of A Cathepsin D Targeted Optical Contrast Agent In A Mouse Model Of Alzheimer's Disease., Jonatan A Snir, Mojmir Suchy, Keith St Lawrence, Robert H E Hudson, Stephen H Pasternak, Robert Bartha

Brain and Mind Institute Researchers' Publications

BACKGROUND: Cathepsin D (CatD) is a lysosomal protease that is elevated early in Alzheimer's disease (AD). We have previously developed a Targeted contrast agent (CA) to detect CatD activity in vivo, consisting of a magnetic resonance imaging/fluorescent moiety linked to a cell penetrating peptide (CPP) by means of a CatD cleavage site and have demonstrated its uptake in the brain of an AD mouse model.

OBJECTIVE: The purpose of this study was to characterize the in vivo retention of a near infra-red fluorescent dye labeled version of this CA.

METHODS: Six adult C57Bl/6 wild-type mice and six adult 5XFAD transgenic …

High-Field Functional Imaging Of Pitch Processing In Auditory Cortex Of The Cat., Blake E. Butler, Amee J Hall, Stephen G Lomber

Brain and Mind Institute Researchers' Publications

The perception of pitch is a widely studied and hotly debated topic in human hearing. Many of these studies combine functional imaging techniques with stimuli designed to disambiguate the percept of pitch from frequency information present in the stimulus. While useful in identifying potential "pitch centres" in cortex, the existence of truly pitch-responsive neurons requires single neuron-level measures that can only be undertaken in animal models. While a number of animals have been shown to be sensitive to pitch, few studies have addressed the location of cortical generators of pitch percepts in non-human models. The current study uses high-field functional …

Automatic Segmentation Of The Hippocampus For Preterm Neonates From Early-In-Life To Term-Equivalent Age., Ting Guo, Julie L Winterburn, Jon Pipitone, Emma G Duerden, Min Tae M Park, Vann Chau, Kenneth J Poskitt, Ruth E Grunau, Anne Synnes, Steven P Miller, M Mallar Chakravarty

Brain and Mind Institute Researchers' Publications

INTRODUCTION: The hippocampus, a medial temporal lobe structure central to learning and memory, is particularly vulnerable in preterm-born neonates. To date, segmentation of the hippocampus for preterm-born neonates has not yet been performed early-in-life (shortly after birth when clinically stable). The present study focuses on the development and validation of an automatic segmentation protocol that is based on the MAGeT-Brain (Multiple Automatically Generated Templates) algorithm to delineate the hippocampi of preterm neonates on their brain MRIs acquired at not only term-equivalent age but also early-in-life.

METHODS: First, we present a three-step manual segmentation protocol to delineate the hippocampus for preterm …

Are There Right Hemisphere Contributions To Visually-Guided Movement? Manipulating Left Hand Reaction Time Advantages In Dextrals., David P Carey, E Grace Otto-De Haart, Gavin Buckingham, H Chris Dijkerman, Eric L Hargreaves, Melvyn A Goodale

Brain and Mind Institute Researchers' Publications

Many studies have argued for distinct but complementary contributions from each hemisphere in the control of movements to visual targets. Investigators have attempted to extend observations from patients with unilateral left- and right-hemisphere damage, to those using neurologically-intact participants, by assuming that each hand has privileged access to the contralateral hemisphere. Previous attempts to illustrate right hemispheric contributions to the control of aiming have focussed on increasing the spatial demands of an aiming task, to attenuate the typical right hand advantages, to try to enhance a left hand reaction time advantage in right-handed participants. These early attempts have not been …

Stability Of Self-Referent Encoding Task Performance And Associations With Change In Depressive Symptoms From Early To Middle Childhood., Brandon L Goldstein, Elizabeth P Hayden, Daniel N Klein

Brain and Mind Institute Researchers' Publications

Depressed individuals exhibit memory biases on the self-referent encoding task (SRET), such that those with depression exhibit poorer recall of positive, and enhanced recall of negative, trait adjectives (referred to as positive and negative processing biases). However, it is unclear when SRET biases emerge, whether they are stable, and if biases predict, or are predicted by, depressive symptoms. To address this, a community sample of 434 children completed the SRET and a depressive symptoms measure at ages 6 and 9. Negative and positive processing exhibited low, but significant, stability. At ages 6 and 9, depressive symptoms correlated with higher negative, …

Fusion Analysis Of First Episode Depression: Where Brain Shape Deformations Meet Local Composition Of Tissue., Mahdi Ramezani, Purang Abolmaesumi, Amir Tahmasebi, Rachael Bosma, Ryan Tong, Tom Hollenstein, Kate Harkness, Ingrid Johnsrude

Brain and Mind Institute Researchers' Publications

Computational neuroanatomical techniques that are used to evaluate the structural correlates of disorders in the brain typically measure regional differences in gray matter or white matter, or measure regional differences in the deformation fields required to warp individual datasets to a standard space. Our aim in this study was to combine measurements of regional tissue composition and of deformations in order to characterize a particular brain disorder (here, major depressive disorder). We use structural Magnetic Resonance Imaging (MRI) data from young adults in a first episode of depression, and from an age- and sex-matched group of non-depressed individuals, and create …

An Fmri Comparison Of Neural Activity Associated With Recognition Of Familiar Melodies In Younger And Older Adults., Ritu Sikka, Lola L Cuddy, Ingrid S Johnsrude, Ashley D Vanstone

Brain and Mind Institute Researchers' Publications

Several studies of semantic memory in non-musical domains involving recognition of items from long-term memory have shown an age-related shift from the medial temporal lobe structures to the frontal lobe. However, the effects of aging on musical semantic memory remain unexamined. We compared activation associated with recognition of familiar melodies in younger and older adults. Recognition follows successful retrieval from the musical lexicon that comprises a lifetime of learned musical phrases. We used the sparse-sampling technique in fMRI to determine the neural correlates of melody recognition by comparing activation when listening to familiar vs. unfamiliar melodies, and to identify age …

Ego Depletion Interferes With Rule-Defined Category Learning But Not Non-Rule-Defined Category Learning., John P Minda, Rahel Rabi

Brain and Mind Institute Researchers' Publications

Considerable research on category learning has suggested that many cognitive and environmental factors can have a differential effect on the learning of rule-defined (RD) categories as opposed to the learning of non-rule-defined (NRD) categories. Prior research has also suggested that ego depletion can temporarily reduce the capacity for executive functioning and cognitive flexibility. The present study examined whether temporarily reducing participants' executive functioning via a resource depletion manipulation would differentially impact RD and NRD category learning. Participants were either asked to write a story with no restrictions (the control condition), or without using two common letters (the ego depletion condition). …

Resilience: A Psychobiological Construct For Pathway Of Suicidality, Amresh Srivastava, Corelee Berlmont, Miky Kaushal, Avinash Desouza, Robbie Campbell, Larry Stitt

Data and Test Instruments

Absttract: Background and objective Resilience which is a neurobiological and behavioral construct may modulate psychopathological trajectory as a ‘final common pathway’ for suicide behavior. Since it allows people to adapt to adversity and bounce back to normalcy, treatments based upon modifcation of resilience may be a possibility. Objective of this prospective, cross-sectional study was to examine association of resilience and suicidality in individuals with psychiatric disorders attending Regional RMHC, St. Thomas and London. Method We measured level of resilience by using Connor-Davidson scale (CD-RISC, cut-off 60), suicidality by Scale for Impact of Suicidality Management, Assessment and Planning of Care brief …

Autism And The Effect Of Introducing A New Noise Source Into Quiet Rural Communities: Risk Factor From Industrial Wind Power Generation, Grace Howell, Debbie Shubat, Carmen Krogh

Data and Test Instruments

Some individuals with Autism Spectrum Disorders (ASD) may react negatively to noise including low-frequency noise, infrasound, vibration and other environmental emissions. There are specific concerns in the Province of Ontario, Canada, related to the exposure of people with autism to the environmental noise and infrasound produced by an additional noise source, in this case from the introduction of industrial-scale wind turbines into quiet rural communities. The objective of this report is to explore the potential for effects of exposure to a new noise source on this specific and vulnerable population. There is a significant research gap regarding the impact of …

Ventilator-Associated Pneumonia Or Bacterial Colonization Of The Airway, What Do Probiotics Decrease?, Saptharishi Lalgudi Ganesan, Sunit C. Singhi, M. Baalaaji

Data and Test Instruments

No abstract provided.

The Manual Ability Classification System: A Scoping Review, Deepa Jeevanantham, Emily Dyszuk, Doreen Bartlett

Physical Therapy Publications

PURPOSE: To examine the use of the Manual Ability Classification System (MACS) and to identify gaps in the literature by conducting a thorough search of existing publications from 2006 to March 2013.

METHODS: An extensive literature search included 15 databases, using the search terms "Manual Ability Classification System" or "MACS" to retrieve relevant abstracts.

RESULTS: A total of 161 articles were identified for final inclusion. The review identified literature that supports the reliability, validity, and stability of the MACS.

CONCLUSIONS: The MACS could be considered as a standard classification for children with cerebral palsy on the basis of manual abilities. …

Low Birth Weight Followed By Postnatal Over-Nutrition In The Guinea Pig Exposes A Predominant Player In The Development Of Vascular Dysfunction., Jennifer A Thompson, Ousseynou Sarr, Karolina Piorkowska, Robert Gros, Timothy Regnault

Paediatrics Publications

The association between intrauterine growth restriction (IUGR) and hypertension is well established, yet the interaction between IUGR and other pathogenic contributors remains ill-defined. This study examined the independent and interactive effects of fetal growth reduction resulting in low birth weight (LBW), and postnatal Western diet (WD) on vascular function. Growth reduction was induced in pregnant guinea pigs by uterine artery ablation. LBW and normal birth weight (NBW) offspring were randomly assigned to a control diet (CD) or a WD. In young adulthood, length-tension curves were generated in aortic rings and responses to methacholine (MCh) were evaluated in the carotid and …

Registration Of In-Vivo To Ex-Vivo Mri Of Surgically Resected Specimens: A Pipeline For Histology To In-Vivo Registration., Maged Goubran, Sandrine De Ribaupierre, Robert R Hammond, Catherine Currie, Jorge G Burneo, Andrew G Parrent, Terry M Peters, Ali R Khan

Medical Biophysics Publications

BACKGROUND: Advances in MRI have the potential to improve surgical treatment of epilepsy through improved identification and delineation of lesions. However, validation is currently needed to investigate histopathological correlates of these new imaging techniques. The purpose of this work is to develop and evaluate a protocol for deformable image registration of in-vivo to ex-vivo resected brain specimen MRI. This protocol, in conjunction with our previous work on ex-vivo to histology registration, completes a registration pipeline for histology to in-vivo MRI, enabling voxel-based validation of novel and existing MRI techniques with histopathology.

NEW METHOD: A combination of image-based and landmark-based 3D …

Functional Lung Avoidance For Individualized Radiotherapy (Flair): Study Protocol For A Randomized, Double-Blind Clinical Trial., Douglas A Hoover, Dante Pi Capaldi, Khadija Sheikh, David A Palma, George B Rodrigues, A Rashid Dar, Edward Yu, Brian Dingle, Mark Landis, Walter Kocha, Michael Sanatani, Mark Vincent, Jawaid Younus, Sara Kuruvilla, Stewart Gaede, Grace Parraga, Brian P Yaremko

Medical Biophysics Publications

BACKGROUND: Although radiotherapy is a key component of curative-intent treatment for locally advanced, unresectable non-small cell lung cancer (NSCLC), it can be associated with substantial pulmonary toxicity in some patients. Current radiotherapy planning techniques aim to minimize the radiation dose to the lungs, without accounting for regional variations in lung function. Many patients, particularly smokers, can have substantial regional differences in pulmonary ventilation patterns, and it has been hypothesized that preferential avoidance of functional lung during radiotherapy may reduce toxicity. Although several investigators have shown that functional lung can be identified using advanced imaging techniques and/or demonstrated the feasibility and …

Free-Breathing Pulmonary (1)H And Hyperpolarized (3)He Mri: Comparison In Copd And Bronchiectasis., Dante P I Capaldi, Khadija Sheikh, Fumin Guo, Sarah Svenningsen, Roya Etemad-Rezai, Harvey O Coxson, Jonathon A Leipsic, David G Mccormack, Grace Parraga

Medical Biophysics Publications

RATIONALE AND OBJECTIVES: In this proof-of-concept demonstration, we aimed to quantitatively and qualitatively compare pulmonary ventilation abnormalities derived from Fourier decomposition of free-breathing (1)H magnetic resonance imaging (FDMRI) to hyperpolarized (3)He MRI in subjects with chronic obstructive pulmonary disease (COPD) and bronchiectasis.

MATERIALS AND METHODS: All subjects provided written informed consent to a protocol approved by a local research ethics board and Health, Canada, and they underwent MRI, computed tomography (CT), spirometry, and plethysmography during a single 2-hour visit. Semiautomated segmentation was used to generate ventilation defect measurements derived from FDMRI and (3)He MRI, and these were compared using analysis …

The Health Initiative Program For Kids (Hip Kids): Effects Of A 1-Year Multidisciplinary Lifestyle Intervention On Adiposity And Quality Of Life In Obese Children And Adolescents -- A Longitudinal Pilot Intervention Study, Dirk E. Bock, Tracy Robinson, Jamie A Seabrook, Meghan Rombeek, Kambiz Norozi, Guido Filler, Ralf Rauch, Cheril L Clarson

Paediatrics Publications

BACKGROUND: Though recent data suggest that multidisciplinary outpatient interventions can have a positive effect on childhood obesity, it is still unclear which program components are most beneficial and how they affect quality of life (QoL). The aim of this study was to determine if a 1-year multidisciplinary, family-centered outpatient intervention based on social cognitive theory would be effective in (i) preventing further increases in BMI and BMI z-score, and (ii) improving QoL in obese children and adolescents.

METHODS: Obese children and adolescents 8-17 years of age and their families participated in this 1-year longitudinal pilot intervention study. The intervention consisted …

Propranolol Therapy For Infantile Hemangioma Is Less Toxic But Longer In Duration Than Corticosteroid Therapy, Kathryn Sawa, Arjang Yazdani, Michael J. Rieder, Guido Filler

Paediatrics Publications

BACKGROUND: Infantile hemangioma is the most common benign, self-limiting tumour of childhood. Treatment is reserved for hemangiomas that obstruct vital structures or cause significant disfigurement. Traditionally, corticosteroids have been the medical treatment of choice. Since 2008, however, propranolol has been rapidly adopted as an effective pharmacological treatment for infantile hemangioma. Published data regarding the long-term side effects of propranolol are currently lacking. OBJECTIVE: To describe the long-term effects of propranolol and corticosteroids on anthropometric measurements (height, body mass index [BMI]) and blood pressure in children. METHODS: A prospective database analysis of all infantile hemangioma patient visits to the pediatric vascular …

The Effectiveness Of Teleglaucoma Versus In-Patient Examination For Glaucoma Screening: A Systematic Review And Meta-Analysis, Sera-Melisa Thomas, Maya M Jeyaraman, Maya Jeyaraman, William G Hodge, Cindy Hutnik, John Costella, Monali S Malvankar-Mehta

Epidemiology and Biostatistics Publications

BACKGROUND: Glaucoma is the leading cause of irreversible visual impairment in the world affecting 60.5 million people worldwide in 2010, which is expected to increase to approximately 79.6 million by 2020. Therefore, glaucoma screening is important to detect, diagnose, and treat patients at the earlier stages to prevent disease progression and vision loss. Teleglaucoma uses stereoscopic digital imaging to take ocular images, which are transmitted electronically to an ocular specialist. The purpose is to synthesize literature to evaluate teleglaucoma, its diagnostic accuracy, healthcare system benefits, and cost-effectiveness.

METHODS: A systematic search was conducted to help locate published and unpublished studies. …

A Modified Evidence-Based Practice- Knowledge, Attitudes, Behaviour And Decisions/Outcomes Questionnaire Is Valid Across Multiple Professions Involved In Pain Management, Qiyun Shi, Bert M Chesworth, Mary Law, R Brian Haynes, Joy C Macdermid

Health and Rehabilitation Sciences Publications

BACKGROUND: A validated and reliable instrument was developed to knowledge, attitudes and behaviours with respect to evidence-based practice (EBB-KABQ) in medical trainees but requires further adaptation and validation to be applied across different health professionals.

METHODS: A modified 33-item evidence-based practice scale (EBP-KABQ) was developed to evaluate EBP perceptions and behaviors in clinicians. An international sample of 673 clinicians interested in treatment of pain (mean age = 45 years, 48% occupational therapists/physical therapists, 25% had more than 5 years of clinical training) completed an online English version of the questionnaire and demographics. Scaling properties (internal consistency, floor/ceiling effects) and construct …

Anatomical, Functional And Metabolic Imaging Of Radiation-Induced Lung Injury Using Hyperpolarized Mri., Giles Santyr, Matthew Fox, Kundan Thind, Elaine Hegarty, Alexei Ouriadov, Michael Jensen, Timothy J Scholl, Jacob Van Dyk, Eugene Wong

Medical Biophysics Publications

MRI of hyperpolarized (129)Xe gas and (13)C-enriched substrates (e.g. pyruvate) presents an unprecedented opportunity to map anatomical, functional and metabolic changes associated with lung injury. In particular, inhaled hyperpolarized (129)Xe gas is exquisitely sensitive to changes in alveolar microanatomy and function accompanying lung inflammation through decreases in the apparent diffusion coefficient (ADC) of alveolar gas and increases in the transfer time (T(tr)) of xenon exchange from the gas and into the dissolved phase in the lung. Furthermore, metabolic changes associated with hypoxia arising from lung injury may be reflected by increases in lactate-to-pyruvate signal ratio obtained by magnetic resonance spectroscopic …

Vitamin D And White Matter Abnormalities In Older Adults: A Cross-Sectional Neuroimaging Study., C Annweiler, T Annweiler, R Bartha, F R Herrmann, R Camicioli, O Beauchet

Medical Biophysics Publications

BACKGROUND AND PURPOSE: Morphological brain changes related to hypovitaminosis D have been poorly studied. In particular, the age-related decrease in vitamin D concentrations may explain the onset of white matter abnormalities (WMA) in older adults. Our objectives were (i) to investigate whether there was an association between serum 25-hydroxyvitamin D (25OHD) concentration and the grade of WMA in older adults and (ii) to determine whether the location of WMA was associated with 25OHD concentration.

METHODS: One hundred and thirty-three Caucasian older community-dwellers with no clinical hydrocephalus (mean 71.6 ± 5.6 years; 43.6% female) received a blood test and a magnetic …

Resilience : An Independent Psychobiological Mental Health Construct (Guest Editorial), Amresh Srivastava

Data and Test Instruments

Survival against trauma is a unique characteristic of all human beings. While a number of factors contribute in building this capacity, resilience appears to be the most important one. Interest in studying resilience arises from number of areas which are of utmost clinical significance such as such as exploring the possibility of at-risk individuals who developing a mental illness]. Resilience is a human capacity to adapt swiftly and successfully to stressful or traumatic events and revert back to a positive state. It is commonly conceptualized as the ability to thrive despite experiencing adversity

P-I-N Heterojunctions With Bifeo3 Perovskite Nanoparticles And P- And N-Type Oxides: Photovoltaic Properties., Soumyo Chatterjee, Abhijit Bera, Amlan J Pal

Medical Biophysics Publications

We formed p-i-n heterojunctions based on a thin film of BiFeO3 nanoparticles. The perovskite acting as an intrinsic semiconductor was sandwiched between a p-type and an n-type oxide semiconductor as hole- and electron-collecting layer, respectively, making the heterojunction act as an all-inorganic oxide p-i-n device. We have characterized the perovskite and carrier collecting materials, such as NiO and MoO3 nanoparticles as p-type materials and ZnO nanoparticles as the n-type material, with scanning tunneling spectroscopy; from the spectrum of the density of states, we could locate the band edges to infer the nature of the active semiconductor materials. The energy level …

A Ventilator Strategy Combining Low Tidal Volume Ventilation, Recruitment Maneuvers, And High Positive End-Expiratory Pressure Does Not Increase Sedative, Opioid, Or Neuromuscular Blocker Use In Adults With Acute Respiratory Distress Syndrome And May Improve Patient Comfort, Sangeeta Mehta, Deborah J. Cook, Yoanna Skrobik, John Muscedere

Anatomy and Cell Biology Publications

Background: The Lung Open Ventilation Study (LOV Study) compared a low tidal volume strategy with an experimental strategy combining low tidal volume, lung recruitment maneuvers, and higher plateau and positive end-expiratory pressures (PEEP) in adults with acute respiratory distress syndrome (ARDS). Herein, we compared sedative, opioid, and neuromuscular blocker (NMB) use among patients managed with the intervention and control strategies and clinicians' assessment of comfort in both groups. Methods: This was an observational substudy of the LOV Study, a randomized trial conducted in 30 intensive care units in Canada, Australia, and Saudi Arabia. In 16 centers, we recorded daily doses …

Education And Training For Suicide Prevention In India, Amresh Srivastava

Data and Test Instruments

No abstract provided.

Atrx Is Required For Maintenance Of The Neuroprogenitor Cell Pool In The Embryonic Mouse Brain, Kieran Ritchie, L Ashley Watson, Benjamin Davidson, Yan Jiang, Nathalie G. Bérubé

Paediatrics Publications

Mutations in the alpha-thalassemia mental retardation X-linked (ATRX) gene cause a spectrum of abnormalities including intellectual disability, developmental delay, seizures, and microcephaly. The ATRX protein is highly enriched at heterochromatic repetitive sequences adjacent to the centromere, and ATRX depletion results in chromosome congression, segregation, and cohesion defects. Here, we show that Cre-mediated inactivation of Atrx in the embryonic mouse (Mus musculus) brain results in expansion of cerebral cortical layer VI, and a concurrent thinning of layers II-IV. We observed increased cell cycle exit during early-mid neurogenesis, and a depletion of apical progenitors by late neurogenesis in the Atrx-null neocortex, explaining …

Exploiting High-Throughput Cell Line Drug Screening Studies To Identify Candidate Therapeutic Agents In Head And Neck Cancer, Anthony C Nichols, Morgan Black, John Yoo, Nicole Pinto, Andrew Fernandes, Benjamin Haibe-Kains, Paul C Boutros, John W Barrett

Oncology Publications

BACKGROUND: There is an urgent need for better therapeutics in head and neck squamous cell cancer (HNSCC) to improve survival and decrease treatment morbidity. Recent advances in high-throughput drug screening techniques and next-generation sequencing have identified new therapeutic targets in other cancer types, but an HNSCC-specific study has not yet been carried out. We have exploited data from two large-scale cell line projects to clearly describe the mutational and copy number status of HNSCC cell lines and identify candidate drugs with elevated efficacy in HNSCC.

METHODS: The genetic landscape of 42 HNSCC cell lines including mutational and copy number data …

Developmental Differences In The Influence Of Phonological Similarity On Spoken Word Processing In Mandarin Chinese., Jeffrey G Malins, Danqi Gao, Ran Tao, James R Booth, Hua Shu, Marc F Joanisse, Li Liu, Amy S Desroches

Brain and Mind Institute Researchers' Publications

The developmental trajectory of spoken word recognition has been well established in Indo-European languages, but to date remains poorly characterized in Mandarin Chinese. In this study, typically developing children (N=17; mean age 10; 5) and adults (N=17; mean age 24) performed a picture-word matching task in Mandarin while we recorded ERPs. Mismatches diverged from expectations in different components of the Mandarin syllable; namely, word-initial phonemes, word-final phonemes, and tone. By comparing responses to different mismatch types, we uncovered evidence suggesting that both children and adults process words incrementally. However, we also observed key developmental differences in how subjects treated onset …