Medicine and Health Sciences Commons^™

Imaging Of Lung Function Using Hyperpolarized Helium-3 Magnetic Resonance Imaging: Review Of Current And Emerging Translational Methods And Applications, Sean Fain, Mark L Schiebler, David G Mccormack, Grace Parraga

Medical Biophysics Publications

During the past several years there has been extensive development and application of hyperpolarized helium-3 (HP (3)He) magnetic resonance imaging (MRI) in clinical respiratory indications such as asthma, chronic obstructive pulmonary disease, cystic fibrosis, radiation-induced lung injury, and transplantation. This review focuses on the state-of-the-art of HP (3)He MRI and its application to clinical pulmonary research. This is not an overview of the physics of the method, as this topic has been covered previously. We focus here on the potential of this imaging method and its challenges in demonstrating new types of information that has the potential to influence clinical …

Exploring Relationships Between Racism, Housing And Child Illness In Remote Indigenous Communities, Naomi Priest, Yin Paradies, Matthew Stevens, Ross Bailie

Aboriginal Policy Research Consortium International (APRCi)

Background Although racism is increasingly acknowledged as a determinant of health, few studies have examined the relationship between racism, housing and child health outcomes. Methods Cross-sectional data from the Housing Improvement and Child Health study collected in ten remote indigenous communities in the Northern Territory, Australia were analysed using hierarchical logistic regression. Carer and householder self-reported racism was measured using a single item and child illness was measured using a carer report of common childhood illnesses. A range of confounders, moderators and mediators were considered, including socio-demographic and household composition, psychosocial measures for carers and householders, community environment, and health-related …

Role Of Alpha 7 Nicotinic Acetylcholine Receptor In Calcium Signaling Induced By Prion Protein Interaction With Stress-Inducible Protein 1, Flavio H. Beraldo, Camila P. Arantes, Tiago G. Santos, Nicolle G. T. Queiroz, Kirk Young, Jane R. Rylett, Regina P. Markus, Marco A. M. Prado, Vilma R. Martins

Anatomy and Cell Biology Publications

The prion protein (PrP(C)) is a conserved glycosylphosphatidyl-inositol-anchored cell surface protein expressed by neurons and other cells. Stress-inducible protein 1 (STI1) binds PrP(C) extracellularly, and this activated signaling complex promotes neuronal differentiation and neuroprotection via the extracellular signal-regulated kinase 1 and 2 (ERK1/2) and cAMP-dependent protein kinase 1 (PKA) pathways. However, the mechanism by which the PrPC-STI1 interaction transduces extracellular signals to the intracellular environment is unknown. We found that in hippocampal neurons, STI1-PrP(C) engagement induces an increase in intracellular Ca(2+) levels. This effect was not detected in PrP(C)-null neurons or wild-type neurons treated with an STI1 mutant unable to …

Cancer Incidence And Mortality In Indigenous Australians In Queensland, 1997–2006, Suzanne P. Moore, Peter K. O'Rourke, Kylie-Ann Mallitt, Gail Garvey, Adèle C. Green, Michael D. Coory, Patricia C. Valery

Aboriginal Policy Research Consortium International (APRCi)

Objective: To examine cancer incidence and mortality in Indigenous Queenslanders. Design, setting and patients: Assessment of indirectly standardised incidence and mortality ratios for Indigenous Australians in Queensland diagnosed with cancer from 1997 to 2006, compared with the total Queensland population. Main outcome measures: Standardised incidence and mortality ratios. Results: Compared with the total Queensland population, Indigenous Queenslanders had a lower overall incidence of cancer (standardised incidence ratio, 0.79; 95% CI, 0.75–0.82), but a higher incidence of some of the more fatal cancer types. Overall cancer mortality was higher (standardised mortality ratio, 1.36; 95% CI, 1.28–1.45) and similar to rates for …

Failing To Ignore: Paradoxical Neural Effects Of Perceptual Load On Early Attentional Selection In Normal Aging, Taylor W. Schmitz, Frederick H.T. Cheng, Eve De Rosa

Brain and Mind Institute Researchers' Publications

We examined visual selective attention under perceptual load - simultaneous presentation of task-relevant and -irrelevant information - in healthy young and older adult human participants to determine whether age differences are observable at early stages of selection in the visual cortices. Participants viewed 50/50 superimposed face/place images and judged whether the faces were male or female, rendering places perceptible but task-irrelevant. Each stimulus was repeated, allowing us to index dynamic stimulus-driven competition from places. Consistent with intact early selection in young adults, we observed no adaptation to unattended places in parahippocampal place area (PPA) and significant adaptation to attended faces …

Nox2 Deficiency Protects Against Streptozotocin-Induced Β-Cell Destruction And Development Of Diabetes In Mice, Fu Li Xiang, Xiangru Lu, Brenda Strutt, David J. Hill, Qingping Feng

Paediatrics Publications

OBJECTIVE - The role of NOX2-containing NADPH oxidase in the development of diabetes is not fully understood. We hypothesized that NOX2 deficiency decreases reactive oxygen species (ROS) production and immune response and protects against streptozotocin (STZ)-induced β-cell destruction and development of diabetes in mice. RESEARCH DESIGN AND METHODS - Five groups of mice-wild-type (WT), NOX2-/-, WT treated with apocynin, and WT adoptively transferred with NOX2-/- or WT splenocytes - were treated with multiple-low-dose STZ. Blood glucose and insulin levels were monitored, and an intraperitoneal glucose tolerance test was performed. Isolated WT and NOX2-/- pancreatic islets were treated with cytokines for …

Epidemiology Of Pediatric Urolithiasis, Ajay P. Sharma, Guido Filler

Paediatrics Publications

Pediatric urolithiasis has increased globally in the last few decades. There has been a change in the pattern of stone composition with an increase in the frequency of kidney stones and a decrease in bladder stones. The role of familial predisposition and environmental factors in pediatric urolithiasis is now better understood. Metabolic factors are more common in pediatric urolithiasis than in adult stone disease. This review updates on the epidemiology of pediatric urolithiasis with a focus on the changing trends in the stone disease, current spectrum of stone disease encountered in clinical practice, individual predisposition and the role of environmental …

The Pathways To Mental Health Care Of First-Episode Psychosis Patients: A Systematic Review., Kelly K. Anderson, Rebecca Fuhrer, Ashok K. Malla

Epidemiology and Biostatistics Publications

BACKGROUND: Although there is agreement on the association between delay in treatment of psychosis and outcome, less is known regarding the pathways to care of patients suffering from a first psychotic episode. Pathways are complex, involve a diverse range of contacts, and are likely to influence delay in treatment. We conducted a systematic review on the nature and determinants of the pathway to care of patients experiencing a first psychotic episode.

METHOD: We searched four databases (Medline, HealthStar, EMBASE, PsycINFO) to identify articles published between 1985 and 2009. We manually searched reference lists and relevant journals and used forward citation …

A Mi'kmaq First Nation Cosmology: Investigating The Practice Of Contemporary Aboriginal Traditional Medicine In Dialogue With Counselling – Toward An Indigenous Therapeutics, Kisiku Sa'qawei Paq'tism Randolph Bowers

Aboriginal Policy Research Consortium International (APRCi)

This paper explores from a Mi’kmaq and Aboriginal standpoint foundational knowledge in Indigenous therapeutics. Based on an eco-social-psycho-spiritual way of working, the article proposes Indigenous cultural models that open a window to a rich cultural repository of meanings associated with Indigenous cosmology, ontology and epistemology. The three layers of meaning, theory and practice within the symbolic ‘Medicine Lodge’ or ‘Place of The Dreaming’ give rise to ways of working that are deeply integrative and wholistic. These forms of Indigenous theory and practice have much to offer the counselling and complimentary health professions.

Neural Reuse: A Fundamental Organizational Principle Of The Brain, Michael Anderson

Brain and Mind Institute Researchers' Publications

An emerging class of theories concerning the functional structure of the brain takes the reuse of neural circuitry for various cognitive purposes to be a central organizational principle. According to these theories, it is quite common for neural circuits established for one purpose to be exapted (exploited, recycled, redeployed) during evolution or normal development, and be put to different uses, often without losing their original functions. Neural reuse theories thus differ from the usual understanding of the role of neural plasticity (which is, after all, a kind of reuse) in brain organization along the following lines: According to neural reuse, …

Hyperpolarized (3)He Magnetic Resonance Imaging-Derived Pulmonary Pressure-Volume Curves, Stephen Choy, Andrew Wheatley, David G Mccormack, Grace Parraga

Medical Biophysics Publications

We aimed to evaluate the potential for the use of hyperpolarized helium-3 magnetic resonance imaging (MRI) apparent diffusion coefficient (ADC) surrogates of alveolar size, together with literature-based morphological parameters in a theoretical model of lung mechanics to simulate noninvasive transpulmonary pressure-volume curves. Fourteen ex-smokers with chronic obstructive pulmonary disease (COPD) (n = 8 stage II, n = 6 stage III/IV COPD) and five age-matched never-smokers, provided written, informed consent and were evaluated at baseline and 26 + or - 2 mo later (n = 15 subjects) using plethysmography, spirometry, and (3)He MRI at 3.0 T. Total lung capacity, residual volume, …

Multiple Mechanisms Of Consciousness: The Neural Correlates Of Emotional Awareness., Jayna M Amting, Steven G Greening, Derek G V Mitchell

Brain and Mind Institute Researchers' Publications

Emotional stimuli, including facial expressions, are thought to gain rapid and privileged access to processing resources in the brain. Despite this access, we are conscious of only a fraction of the myriad of emotion-related cues we face everyday. It remains unclear, therefore, what the relationship is between activity in neural regions associated with emotional representation and the phenomenological experience of emotional awareness. We used functional magnetic resonance imaging and binocular rivalry to delineate the neural correlates of awareness of conflicting emotional expressions in humans. Behaviorally, fearful faces were significantly more likely to be perceived than disgusted or neutral faces. Functionally, …

Deficits In Attention To Emotional Stimuli Distinguish Youth With Severe Mood Dysregulation From Youth With Bipolar Disorder., Brendan A Rich, Melissa A Brotman, Daniel P Dickstein, Derek G V Mitchell, R James R Blair, Ellen Leibenluft

Brain and Mind Institute Researchers' Publications

Studying attention in the context of emotional stimuli may aid in differentiating pediatric bipolar disorder (BD) from severe mood dysregulation (SMD). SMD is characterized by chronic irritability, arousal, and hyper-reactivity; SMD youth frequently receive a BD diagnosis although they do not meet DSM-IV criteria for BD because they lack manic episodes. We compared 57 BD (14.4 +/- 2.9 years old, 56% male), 41 SMD (12.6 +/- 2.6 years old, 66% male), and 33 control subjects (13.7 +/- 2.5 years old, 52% male) using the Emotional Interrupt task, which examines how attention is impacted by positive, negative, or neutral distracters. We …

Optimal Slice Thickness For Cone-Beam Ct With On-Board Imager., Kyt Seet, A Barghi, Slav Yartsev, Jacob Van Dyk

Oncology Publications

PURPOSE: To find the optimal slice thickness (Δτ) setting for patient registration with kilovoltage cone-beam CT (kVCBCT) on the Varian On Board Imager (OBI) system by investigating the relationship of slice thickness to automatic registration accuracy and contrast-to-noise ratio.

MATERIALS AND METHOD: Automatic registration was performed on kVCBCT studies of the head and pelvis of a RANDO anthropomorphic phantom. Images were reconstructed with 1.0 ≤ Δτ (mm) ≤ 5.0 at 1.0 mm increments. The phantoms were offset by a known amount, and the suggested shifts were compared to the known shifts by calculating the residual error. A uniform cylindrical phantom …

Chronic Obstructive Pulmonary Disease: Longitudinal Hyperpolarized (3)He Mr Imaging, Miranda Kirby, Lindsay Mathew, Andrew Wheatley, Giles E Santyr, David G Mccormack, Grace Parraga

Medical Biophysics Publications

PURPOSE: To quantitatively evaluate a small pilot group of ex-smokers with chronic obstructive pulmonary disease (COPD) and healthy volunteers during approximately 2 years by using hyperpolarized helium 3 ((3)He) magnetic resonance (MR) imaging.

MATERIALS AND METHODS: All subjects provided written informed consent to the study protocol, which was approved by the local research ethics board and Health Canada and was compliant with the Personal Information Protection and Electronic Documents Act and HIPAA. Hyperpolarized (3)He MR imaging, hydrogen 1 MR imaging, spirometry, and plethysmography were performed in 15 ex-smokers with COPD and five healthy volunteers (with the same mean age and …

If You Build It, They Still May Not Come: Outcomes And Process Of Implementing A Community-Based Integrated Knowledge Translation Mapping Innovation, S. Michelle Driedger, Anita Kothari, Ian D. Graham, Elizabeth Cooper, Eric J. Crighton, Melanie Zahab, Jason Morrison, Michael Sawada

Health Studies Publications

Background: Maps and mapping tools through geographic information systems (GIS) are highly valuable for turning data into useful information that can help inform decision-making and knowledge translation (KT) activities. However, there are several challenges involved in incorporating GIS applications into the decision-making process. We highlight the challenges and opportunities encountered in implementing a mapping innovation as a KT strategy within the non-profit (public) health sector, reflecting on the processes and outcomes related to our KT innovations.

Methods: A case study design, whereby the case is defined as the data analyst and manager dyad (a two person team) in selected Ontario …

Management Of Devastating Ocular Trauma--Experience Of Maxillofacial Surgeons Deployed To A Forward Field Hospital, M. J. Ansell, J. Breeze, Vivian C. Mcalister, M. D. Williams

Surgery Publications

Combat-related eye injuries continue to increase in frequency and are generally secondary to Improvised Explosive Devices. Many ocular injuries are potentially preventable by the wearing of ballistic eye protection. The management of penetrating eye trauma is normally outside the routine practice of maxillofacial surgeons in the UK. The aim of this paper is to describe the surgical techniques used in the modern management of devastating ocular trauma including selected case examples managed by British military maxillofacial surgeons deployed to Afghanistan.

Psychoendocrinology (Thyroid Hormone) And Early Psychosis: Preliminary Findings, Amresh Srivastava, Megan Johnston, Lenore Purde, Robbie Campbell

Psychiatry Presentations

No abstract provided.

Serum Lipids And Suicidality In Early Psychosis: Is There A Connection? A Preliminary Study, Amresh Srivastava, Megan Johnston, Lenore Purde, Robbie Campbell

Psychiatry Presentations

No abstract provided.

In-Theater Peritoneal Dialysis For Combat-Related Renal Failure, Joseph S. Pina, Soraya Moghadam, Howard M. Cushner, Greg J. Beilman, Vivian C. Mcalister

Surgery Publications

BACKGROUND: Complications of renal failure may prevent timely evacuation of injured soldiers. Conventional renal replacement therapy is not available in forward surgical units. METHODS: Records of in-theater improvised peritoneal dialysis (IPD) in level III hospitals or forward surgical units in Iraq or Afghanistan were reviewed to determine the following: cause of renal failure and associated injuries; type of dialysate, peritoneal access, and exchange technique; and patient outcome. These data were used to propose method for IPD using commonly available materials. RESULTS: IPD is described in four patients. Abdominal or chest drains were used with either improvised dextrose-electrolyte solution or commercial …

Linking Brain-Wide Multivoxel Activation Patterns To Behaviour: Examples From Language And Math, Rajeev D.S. Raizada, Feng Ming Tsao, Huei Mei Liu, Ian D. Holloway, Daniel Ansari, Patricia K. Kuhl

Paediatrics Publications

A key goal of cognitive neuroscience is to find simple and direct connections between brain and behaviour. However, fMRI analysis typically involves choices between many possible options, with each choice potentially biasing any brain-behaviour correlations that emerge. Standard methods of fMRI analysis assess each voxel individually, but then face the problem of selection bias when combining those voxels into a region-of-interest, or ROI. Multivariate pattern-based fMRI analysis methods use classifiers to analyse multiple voxels together, but can also introduce selection bias via data-reduction steps as feature selection of voxels, pre-selecting activated regions, or principal components analysis. We show here that …

Should 'Risk Syndrome Of Psychosis' Be Included In Dsm V As A Diagnosis? A Road Towards Preventive Psychiatry, Amresh Srivastava

Psychiatry Presentations

No abstract provided.

Enhancing Risk Assessment Across Mental Health Services, Amresh Srivastava, Megan Johnston, Charles Nelson

Psychiatry Presentations

No abstract provided.

Dysautonomia Due To Reduced Cholinergic Neurotransmission Causes Cardiac Remodeling And Heart Failure, Aline Lara, Denis D. Damasceno, Rita Pires, Robert Gros, Eneas R. Gomes, Mariana Gavioli, Ricardo F. Lima, Diogo Guimaraes, Patricia Lima, Carlos Roberto Bueno Jr., Anilton Vasconcelos, Danilo Roman-Campos, Cristiane A. S. Menezes, Raquel A. Sirvente, Vera M. Salemi, Charles Mady, Marc G. Caron, Anderson J. Ferreira, Patricia C. Brum, Rodrigo R. Resende, Jader S. Cruz, Marcus Vinicius Gomez, Vania F. Prado, Alvair P. De Almeida, Marco A. M. Prado, Silvia Guatimosim

Anatomy and Cell Biology Publications

Overwhelming evidence supports the importance of the sympathetic nervous system in heart failure. In contrast, much less is known about the role of failing cholinergic neurotransmission in cardiac disease. By using a unique genetically modified mouse line with reduced expression of the vesicular acetylcholine transporter (VAChT) and consequently decreased release of acetylcholine, we investigated the consequences of altered cholinergic tone for cardiac function. M-mode echocardiography, hemodynamic experiments, analysis of isolated perfused hearts, and measurements of cardiomyocyte contraction indicated that VAChT mutant mice have decreased left ventricle function associated with altered calcium handling. Gene expression was analyzed by quantitative reverse transcriptase …

Motor Output Evoked By Subsaccadic Stimulation Of Primate Frontal Eye Fields., Brian D Corneil, James K Elsley, Benjamin Nagy, Sharon L Cushing

Brain and Mind Institute Researchers' Publications

In addition to its role in shifting the line of sight, the oculomotor system is also involved in the covert orienting of visuospatial attention. Causal evidence supporting this premotor theory of attention, or oculomotor readiness hypothesis, comes from the effect of subsaccadic threshold stimulation of the oculomotor system on behavior and neural activity in the absence of evoked saccades, which parallels the effects of covert attention. Here, by recording neck-muscle activity from monkeys and systematically titrating the level of stimulation current delivered to the frontal eye fields (FEF), we show that such subsaccadic stimulation is not divorced from immediate motor …

Neuropilin 1 Directly Interacts With Fer Kinase To Mediate Semaphorin3a-Induced Death Of Cortical Neurons, Susan X. Jiang, Shawn N. Whitehead, Amy Aylsworth, Bogdan Zurakowski, Kenneth Chan, Jianjun Li, Sheng T. Hou

Anatomy and Cell Biology Publications

Neuropilins (NRPs) are receptors for the major chemorepulsive axonal guidance cue semaphorins (Sema). The interaction of Sema3A/NRP1 during development leads to the collapse of growth cones. Here we show that Sema3A also induces death of cultured cortical neurons through NRP1. A specific NRP1 inhibitory peptide ameliorated Sema3A-evoked cortical axonal retraction and neuronal death. Moreover, Sema3A was also involved in cerebral ischemia-induced neuronal death. Expression levels of Sema3A and NRP1, but not NRP2, were significantly increased early during brain reperfusion following transient focal cerebral ischemia. NRP1 inhibitory peptide delivered to the ischemic brain was potently neuroprotective and prevented the loss of …

Theta-Activity In Anterior Cingulate Cortex Predicts Task Rules And Their Adjustments Following Errors, Thilo Womelsdorf, Kevin Johnston, Martin Vinck, Stefan Everling

Brain and Mind Institute Researchers' Publications

Accomplishing even simple tasks depend on neuronal circuits to configure how incoming sensory stimuli map onto responses. Controlling these stimulus-response (SR) mapping rules relies on a cognitive control network comprising the anterior cingulate cortex (ACC). Single neurons within the ACC convey information about currently relevant SR mapping rules and signal unexpected action outcomes, which can be used to optimize behavioral choices. However, its functional significance and the mechanistic means of interaction with other nodes of the cognitive control network remain elusive and poorly understood. Here, we report that core aspects of cognitive control are encoded by rhythmic theta-band activity within …

The Prevalence And Causes Of Vision Loss In Indigenous Australians: The National Indigenous Eye Health Survey, Hugh R. Taylor, Jing Xie, Sarah Fox, Ross A. Dunn, Anna-Lena Arnold, Jill E. Keeffe

Aboriginal Policy Research Consortium International (APRCi)

Aim: To determine the prevalence and causes of vision loss in Indigenous Australians. Design, setting and participants: A national, stratified, random cluster sample was drawn from 30 communities across Australia that each included about 300 Indigenous people of all ages. A sample of non-Indigenous adults aged 􏱄 40 years was also tested at several remote sites for comparison. Participants were examined using a standardised protocol that included a questionnaire (self-administered or completed with the help of field staff), visual acuity (VA) testing on presentation and after correction, visual field testing, trachoma grading, and fundus and lens photography. The data were …

Hip Fracture Types In Men And Women Change Differently With Age, David A. Tanner, Marita Kloseck, Richard G. Crilly, Bert Chesworth, Jason Gilliland

Health Studies Publications

BACKGROUND: Hip fractures are expensive and a frequent cause of morbidity and mortality in the elderly. In most studies hip fractures have been viewed as a unitary fracture but recently the two main types of fracture (intertrochanteric and subcapital) have been viewed as two fractures with a different etiology and requiring a different approach to prevention. The relative proportion of intertrochanteric fractures increases with age in women. In previous studies no particular pattern in men has been noted. In this study, we explored changes in the relative proportion of the two fracture types with age in the two genders. METHODS: …

E-Mail Communication In Paediatrics: Ethical And Clinical Considerations, Susan Albersheim

Paediatrics Publications

E-mail has become a commonplace ‘procedure’ in medical practice because it is efficient and inexpensive. However, there are potential misuses and abuses of this form of written communication, with clinical and ethical implications. Common uses of e-mail in paediatics include general communication with colleagues in a professional setting; electronic formal consultation, in which patient confidentiality is paramount; electronic ‘curbside’ consultation, which may be perceived as a formal consultation; electronic discussion groups, which lack peer review; communication with current patients or their parents, which should be limited to simple, nonurgent issues; and communication with individuals seeking medical advice who are not …