Medicine and Health Sciences Commons^™

Leg Bone Geometry In Type 2 Diabetes Mellitus, Helen Honig

Masters of Clinical Anatomy Projects

The objective was to investigage the effects of type 2 diabetes mellitus (T2DM) on tibial cortical and medullary cross-sectional areas (CSA) using magnetic resonance imaging. Sequential 1mm-thick slice images were acquired of the right leg from the tibial plateau to the talus in 8 individuals with T2DM and 9 age- and sex-matched (32 to 79 y) controls. The CSA (cm 2) was measured at 3 sites, 20%, 50%, and 80% of tibial length, by a blinded analyzer. At the 20% site, medullary CSA in T2DM was significanltly greater than controls (mean ± SD: 5.9 ± 1.2 vs. 4.8 ± 0.7). …

The Effect Of Noise Exposure On Inhibitory Neurotransmission In The Auditory, Visual And Multisensory Cortices In Rats, Sarah Fitzpatrick

Masters of Clinical Anatomy Projects

It is well established that high-intensity noise exposure can induce structural and physiological changes in the primary auditory cortex, such as impaired GABA neurotransmission, which leads to a reduced level of GABA-synthesizing enzymes (i.e., GAD65/67). At present, however, it remains unknown how partial hearing loss affects GABA neurotransmission in areas of the cortex that process sound as well as other sensory modalities (e.g., visual stimuli). In the present study, we are using a rat model to investigate our working hypothesis that noise-induced hearing loss causes a differential effect on GAD67 levels in the various cortical areas capable of sound processing, …

Beyond Silence: Protocol For A Randomized Parallel-Group Trial Comparing Two Approaches To Workplace Mental Health Education For Healthcare Employees, Sandra Moll, Scott Burton Patten, Heather Stuart, Bonnie Kirsh, Joy Christine Macdermid

Bone and Joint Institute

© 2015 Moll et al.; licensee BioMed Central. Background: Mental illness is a significant and growing problem in Canadian healthcare organizations, leading to tremendous personal, social and financial costs for individuals, their colleagues, their employers and their patients. Early and appropriate intervention is needed, but unfortunately, few workers get the help that they need in a timely way due to barriers related to poor mental health literacy, stigma, and inadequate access to mental health services. Workplace education and training is one promising approach to early identification and support for workers who are struggling. Little is known, however, about what approach …

Survival Prediction In High-Grade Gliomas Using Ct Perfusion Imaging., Timothy Pok Chi Yeung, Yong Wang, Wenqing He, Benedetta Urbini, Roberta Gafà, Linda Ulazzi, Slav Yartsev, Glenn Bauman, Ting-Yim Lee, Enrico Fainardi

Medical Biophysics Publications

Patients with high-grade gliomas usually have heterogeneous response to surgery and chemoirradiation. The objectives of this study were (1) to evaluate serial changes in tumor volume and perfusion imaging parameters and (2) to determine the value of these data in predicting overall survival (OS). Twenty-nine patients with World Health Organization grades III and IV gliomas underwent magnetic resonance (MR) and computed tomography (CT) perfusion examinations before surgery, and 1, 3, 6, 9, and 12 months after radiotherapy. Serial measurements of tumor volumes and perfusion parameters were evaluated by receiver operating characteristic analysis, Cox proportional hazards regression, and Kaplan-Meier survival analysis …

Human Severe Sepsis Cytokine Mixture Increases Beta 2-Integrin-Dependent Polymorphonuclear Leukocyte Adhesion To Cerebral Microvascular Endothelial Cells In Vitro, Chris Blom, Brittany L. Deller, Douglas D. Fraser, Eric K. Patterson, Claudio M. Martin, Bryan Young, Patricia C. Liaw, Payam Yazdan-Ashoori, Angelica Oritz, Brian Webb, Greg Kilmer, David E. Carter, Gediminas Cepinskas

Anatomy and Cell Biology Publications

Introduction: Sepsis-associated encephalopathy (SAE) is a state of acute brain dysfunction in response to a systemic infection. We propose that systemic inflammation during sepsis causes increased adhesion of leukocytes to the brain microvasculature, resulting in blood-brain barrier dysfunction. Thus, our objectives were to measure inflammatory analytes in plasma of severe sepsis patients to create an experimental cytokine mixture (CM), and to use this CM to investigate the activation and interactions of polymorphonuclear leukocytes (PMN) and human cerebrovascular endothelial cells (hCMEC/D3) in vitro. Methods: The concentrations of 41 inflammatory analytes were quantified in plasma obtained from 20 severe sepsis patients and …

Effect Of Gamma Radiation On Growth And Mycotoxins Production Of Alternaria Alternata, Danny Karlet

Anatomy and Cell Biology Publications

The ubiquitous genus Alternaria contains many species that are able to invade cereals, oleaginous plants and other crops. Alternaria alternata is considered one of the most important species and can produce several mycotoxins under favourable conditions of temperature and humidity, including the economically important toxins: alternariol (AOH) and alternariol monomethyl ether (AME). The aim of this study was to evaluate the radio-sensitivity of Alternaria alternata spores through different gamma radiation doses. A. alternata growth and the production of AOH and AME were then analyzed. After fungal irradiation with 2 kGy, 5 kGy and 7 kGy, the spores were suspended with …

Critical Care Capacity In Canada: Results Of A National Cross-Sectional Study, Robert A. Fowler, Philip Abdelmalik, Gordon Wood, Denise Foster, Noel Gibney, Natalie Bandrauk, Alexis F. Turgeon, Francois Lamontagne, Anand Kumar, Ryan Zarychanski, Rob Green, Sean M. Bagshaw, Henry T. Stelfox, Ryan Foster, Peter Dodek, Susan Shaw, John Granton, Bernard Lawless, Andrea Hill, Louise Rose, Neill K. Adhikari, Damon C. Scales, Deborah J. Cook, John C. Marshall, Philippe Jouvet

Anatomy and Cell Biology Publications

Introduction: Intensive Care Units (ICUs) provide life-supporting treatment; however, resources are limited, so demand may exceed supply in the event of pandemics, environmental disasters, or in the context of an aging population. We hypothesized that comprehensive national data on ICU resources would permit a better understanding of regional differences in system capacity. Methods: After the 2009-2010 Influenza A (H1N1) pandemic, the Canadian Critical Care Trials Group surveyed all acute care hospitals in Canada to assess ICU capacity. Using a structured survey tool administered to physicians, respiratory therapists and nurses, we determined the number of ICU beds, ventilators, and the ability …

Evidence-Based Recommendations For Genetic Diagnosis Of Familial Mediterranean Fever, Gabriella Giancane, Nienke M.Ter Haar, Nico Wulffraat, Sebastiaan J. Vastert, Karyl Barron, Veronique Hentgen, Tilmann Kallinich, Huri Ozdogan, Jordi Anton, Paul Brogan, Luca Cantarini, Joost Frenkel, Caroline Galeotti, Marco Gattorno, Gilles Grateau, Michael Hofer, Isabelle Kone-Paut, Jasmin Kuemmerle-Deschner, Helen J. Lachmann, Anna Simon, Erkan Demirkaya, Brian Feldman, Yosef Uziel, Seza Ozen

Paediatrics Publications

Familial Mediterranean fever (FMF) is a disease of early onset which can lead to significant morbidity. In 2012, Single Hub and Access point for pediatric Rheumatology in Europe (SHARE) was launched with the aim of optimising and disseminating diagnostic and management regimens for children and young adults with rheumatic diseases. The objective was to establish recommendations for FMF focusing on provision of diagnostic tools for inexperienced clinicians particularly regarding interpretation of MEFV mutations. Evidencebased recommendations were developed using the European League against Rheumatism standard operating procedure. An expert committee of paediatric rheumatologists defined search terms for the systematic literature review. …

In-Vivo Longitudinal Mri Study: An Assessment Of Melanoma Brain Metastases In A Clinically Relevant Mouse Model., Mariama N Henry, Yuhua Chen, Catherine D Mcfadden, Felicia C Simedrea, Paula J Foster

Medical Biophysics Publications

Brain metastases are an important clinical problem. Few animal models exist for melanoma brain metastases; many of which are not clinically relevant. Longitudinal MRI was implemented to examine the development of tumors in a clinically relevant mouse model of melanoma brain metastases. Fifty thousand human metastatic melanoma (A2058) cells were injected intracardially into nude mice. Three Tesla MRI was performed using a custom-built gradient insert coil and a mouse solenoid head coil. Imaging was performed on consecutive days at four time points. Tumor burden and volumes of metastases were measured from balanced steady-state free precession image data. Metastases with a …

Surgical Approach In Primary Total Hip Arthroplasty: Anatomy, Technique And Clinical Outcomes, Stephen Petis, James L. Howard, Brent L. Lanting, Edward M. Vasarhelyi

Bone and Joint Institute

©2015 8872147 Canada Inc. Total hip arthroplasty (THA) has revolutionized the treatment of hip arthritis. A number of surgical approaches to the hip joint exist, each with unique advantages and disadvantages. The most commonly used approaches include the direct anterior, direct lateral and posterior approaches. A number of technical intricacies allow safe and efficient femoral and acetabular reconstruction when using each approach. Hip dislocation, abductor insufficiency, fracture and nerve injury are complications of THA, although their relative risk varies by approach. Numerous clinical trials have sought to elicit differences in patient-reported outcomes, complication rates and return to function among the …

Motor Skill Learning Between Selection And Execution., Jörn Diedrichsen, Katja Kornysheva

Brain and Mind Institute Researchers' Publications

Learning motor skills evolves from the effortful selection of single movement elements to their combined fast and accurate production. We review recent trends in the study of skill learning which suggest a hierarchical organization of the representations that underlie such expert performance, with premotor areas encoding short sequential movement elements (chunks) or particular component features (timing/spatial organization). This hierarchical representation allows the system to utilize elements of well-learned skills in a flexible manner. One neural correlate of skill development is the emergence of specialized neural circuits that can produce the required elements in a stable and invariant fashion. We discuss …

The Human Motor System Alters Its Reaching Movement Plan For Task-Irrelevant, Positional Forces., Joshua G A Cashaback, Heather R Mcgregor, Paul L Gribble

Brain and Mind Institute Researchers' Publications

The minimum intervention principle and the uncontrolled manifold hypothesis state that our nervous system only responds to force perturbations and sensorimotor noise if they affect task success. This idea has been tested in muscle and joint coordinate frames and more recently using workspace redundancy (e.g., reaching to large targets). However, reaching studies typically involve spatial and or temporal constraints. Constrained reaches represent a small proportion of movements we perform daily and may limit the emergence of natural behavior. Using more relaxed constraints, we conducted two reaching experiments to test the hypothesis that humans respond to task-relevant forces and ignore task-irrelevant …

Seasonal Change In The Avian Hippocampus., David F Sherry, Scott A Macdougall-Shackleton

Brain and Mind Institute Researchers' Publications

The hippocampus plays an important role in cognitive processes, including memory and spatial orientation, in birds. The hippocampus undergoes seasonal change in food-storing birds and brood parasites, there are changes in the hippocampus during breeding, and further changes occur in some species in association with migration. In food-storing birds, seasonal change in the hippocampus occurs in fall and winter when the cognitively demanding behaviour of caching and retrieving food occurs. The timing of annual change in the hippocampus of food-storing birds is quite variable, however, and appears not to be under photoperiod control. A variety of factors, including cognitive performance, …

Developmental Specialization Of The Left Parietal Cortex For The Semantic Representation Of Arabic Numerals: An Fmr-Adaptation Study, Stephan E. Vogel, Celia Goffin, Daniel Ansari

Brain and Mind Institute Researchers' Publications

The way the human brain constructs representations of numerical symbols is poorly understood. While increasing evidence from neuroimaging studies has indicated that the intraparietal sulcus (IPS) becomes increasingly specialized for symbolic numerical magnitude representation over developmental time, the extent to which these changes are associated with age-related differences in symbolic numerical magnitude representation or with developmental changes in non-numerical processes, such as response selection, remains to be uncovered. To address these outstanding questions we investigated developmental changes in the cortical representation of symbolic numerical magnitude in 6- to 14-year-old children using a passive functional magnetic resonance imaging adaptation design, thereby …

Impact Of Incremental Perfusion Loss On Oxygen Transport In A Capillary Network Mathematical Model., Graham M Fraser, Michael D Sharpe, Daniel Goldman, Christopher G Ellis

Medical Biophysics Publications

OBJECTIVES: To quantify how incremental capillary perfusion loss, such as that seen in experimental models of sepsis, affects tissue oxygenation using a computation model of oxygen transport.

METHODS: A computational model was applied to capillary networks with dimensions 84x168x342 (NI) and 70x157x268 (NII) μm, reconstructed in vivo from rat skeletal muscle. Functional capillary density (FCD) loss was applied incrementally up to ~40% and combined with high tissue oxygen consumption to simulate severe sepsis.

RESULTS: A loss of ~40% FCD loss decreased median tissue PO2 to 22.9 and 20.1 mmHg in NI and NII compared to 28.1 and 27.5 mmHg under …

Pulmonary Inflammation Is Regulated By The Levels Of The Vesicular Acetylcholine Transporter, Nathalia M. Pinheiro, Claudia J. C. P. Miranda, Adenir Perini, Niels O. S. Camara, Soraia K. P. Costa, Maria Isabel C. Alonso-Vale, Luciana C. Caperuto, Iolanda F. L. C. Tiberio, Marco A. M. Prado, Milton A. Martins, Vania F. Prado, Carla M. Prado

Anatomy and Cell Biology Publications

Acetylcholine (ACh) plays a crucial role in physiological responses of both the central and the peripheral nervous system. Moreover, ACh was described as an anti-inflammatory mediator involved in the suppression of exacerbated innate response and cytokine release in various organs. However, the specific contributions of endogenous release ACh for inflammatory responses in the lung are not well understood. To address this question we have used mice with reduced levels of the vesicular acetylcholine transporter (VAChT), a protein required for ACh storage in secretory vesicles. VAChT deficiency induced airway inflammation with enhanced TNF-alpha and IL-4 content, but not IL-6, IL-13 and …

Maternal Nicotine Exposure Leads To Impaired Disulfide Bond Formation And Augmented Endoplasmic Reticulum Stress In The Rat Placenta, Michael Wong, Catherine J. Nicholson, Alison C. Holloway, Daniwl Hardy

Physiology and Pharmacology Publications

Maternal nicotine exposure has been associated with many adverse fetal and placental outcomes. Although underlying mechanisms remain elusive, recent studies have identified that augmented endoplasmic reticulum (ER) stress is linked to placental insufficiency. Moreover, ER function depends on proper disulfide bond formation-a partially oxygen-dependent process mediated by protein disulfide isomerase (PDI) and ER oxidoreductases. Given that nicotine compromised placental development in the rat, and placental insufficiency has been associated with poor disulfide bond formation and ER stress, we hypothesized that maternal nicotine exposure leads to both placental ER stress and impaired disulfide bond formation. To test this hypothesis, female Wistar …

The Dissociative Subtype Of Posttraumatic Stress Disorder: Unique Resting-State Functional Connectivity Of Basolateral And Centromedial Amygdala Complexes., Andrew A Nicholson, Maria Densmore, Paul A Frewen, Jean Théberge, Richard W J Neufeld, Margaret C Mckinnon, Ruth A Lanius

Medical Biophysics Publications

Previous studies point towards differential connectivity patterns among basolateral (BLA) and centromedial (CMA) amygdala regions in patients with posttraumatic stress disorder (PTSD) as compared to controls. Here, we describe the first study to compare directly connectivity patterns of the BLA and CMA complexes between PTSD patients with and without the dissociative subtype (PTSD+DS and PTSD-DS, respectively). Amygdala connectivity to regulatory prefrontal regions and parietal regions involved in consciousness and proprioception were expected to differ between these two groups based on differential limbic regulation and behavioural symptoms. PTSD patients (n=49), with (n=13) and without (n=36) the dissociative subtype, and age-matched healthy …

A Biomechanical Approach For In Vivo Lung Tumor Motion Prediction During External Beam Radiation Therapy, Abbas Samani, Elham Karami, Ting-Yim Lee, Stewart Gaede

Medical Biophysics Publications

No abstract provided.

Modulation Of Type Ii Tgf-Β Receptor Degradation By Integrin-Linked Kinase, Linda Vi, Stellar Boo, Samar Sayedyahossein, Randeep K. Singh, Sarah Mclean, Gianni M. Di Guglielmo, Lina Dagnino

Paediatrics Publications

Cutaneous responses to injury, infection, and tumor formation involve the activation of resident dermal fibroblasts and subsequent transition to myofibroblasts. The key for induction of myofibroblast differentiation is the activation of transforming growth factor-β (TGF-β) receptors and stimulation of integrins and their associated proteins, including integrin-linked kinase (ILK). Cross-talk processes between TGF-β and ILK are crucial for myofibroblast formation, as ILK-deficient dermal fibroblasts exhibit impaired responses to TGF-β receptor stimulation. We now show that ILK associates with type II TGF-β receptors (TβRII) in ligand- and receptor kinase activity-independent manners. In cells with targeted Ilk gene inactivation, cellular levels of TβRII …

Collectivization Of Vascular Smooth Muscle Cells Via Tgf-Β-Cadherin-11-Dependent Adhesive Switching., Brittany Balint, Hao Yin, Subrata Chakrabarti, Michael W A Chu, Stephen M Sims, J Geoffrey Pickering

Medical Biophysics Publications

OBJECTIVE: Smooth muscle cells (SMCs) in healthy arteries are arranged as a collective. However, in diseased arteries, SMCs commonly exist as individual cells, unconnected to each other. The purpose of this study was to elucidate the events that enable individualized SMCs to enter into a stable and interacting cell collective.

APPROACH AND RESULTS: Human SMCs stimulated to undergo programmed collectivization were tracked by time-lapse microscopy. We uncovered a switch in the behavior of contacting SMCs from semiautonomous motility to cell-cell adherence. Central to the cell-adherent phenotype was the formation of uniquely elongated adherens junctions, ≤60 μm in length, which appeared …

Evidence Of Ventricular Contamination Of The Optical Signal In Preterm Neonates With Post Hemorrhagic Ventricle Dilation, J Kishimoto, M Diop, S De Ribaupierre, Dsc Lee, K St. Lawrence

Medical Biophysics Publications

No abstract provided.

Resting State And Diffusion Neuroimaging Predictors Of Clinical Improvements Following Constraint-Induced Movement Therapy In Children With Hemiplegic Cerebral Palsy., Kathryn Y Manning, Darcy Fehlings, Ronit Mesterman, Jan Willem Gorter, Lauren Switzer, Craig Campbell, Ravi S Menon

Medical Biophysics Publications

The aim was to identify neuroimaging predictors of clinical improvements following constraint-induced movement therapy. Resting state functional magnetic resonance and diffusion tensor imaging data was acquired in 7 children with hemiplegic cerebral palsy. Clinical and magnetic resonance imaging (MRI) data were acquired at baseline and 1 month later following a 3-week constraint therapy regimen. A more negative baseline laterality index characterizing an atypical unilateral sensorimotor resting state network significantly correlated with an improvement in the Canadian Occupational Performance Measure score (r = -0.81, P = .03). A more unilateral network with decreased activity in the affected hemisphere was associated with …

Investigation Of The Best Model To Characterize Diffuse Correlation Spectroscopy Measurements Acquired Directly On The Brain, K Verdecchia, M Diop, K St. Lawrence

Medical Biophysics Publications

No abstract provided.

Follow-Up Of Patients After Stereotactic Radiation For Lung Cancer: A Primer For The Nonradiation Oncologist., Kitty Huang, David A Palma

Medical Biophysics Publications

BACKGROUND: The use of stereotactic ablative radiotherapy (SABR) as primary treatment for early stage non-small-cell lung cancer, or for ablation of metastases, has increased rapidly in the past decade. With local recurrence rates reported at approximately 10%, and a patient population that is becoming increasingly fit and amenable to salvage treatment, appropriate multidisciplinary follow-up care is critical. Appropriate follow-up will allow for detection and management of radiation-related toxicity, early detection of recurrent disease and differentiation of recurrence from radiation-induced lung injury.

METHODS: This narrative review summarizes issues surrounding follow-up of patients treated with SABR in the context of a multidisciplinary …

Effect Of Taper Design On Trunnionosis In Metal On Polyethylene Total Hip Arthroplasty., Sok Chuen Tan, Matthew G Teeter, Christopher Del Balso, James L Howard, Brent A Lanting

Medical Biophysics Publications

This study examines how taper design affects corrosion and fretting at the head trunnion surface. All hip prostheses retrieved between 1999 and 2013 with 28mm/+0 heads were selected, resulting in 44 cobalt-chrome-on-polyethylene implants, representing six taper designs. Mean implantation time: 8.9±3.7years. The femoral head tapers were scored for fretting and corrosion using the Goldberg scale as both a combined score and by three zones (apex, central and base). There was no difference in age (P=0.34), BMI (P=0.29), or implantation time (P=0.19) between taper groups. The 11/13 taper had the highest combined corrosion and fretting score, but no difference (P=0.22) between …

Effect Of Ascorbate On Plasminogen Activator Inhibitor-1 Expression And Release From Platelets And Endothelial Cells In An In-Vitro Model Of Sepsis., Scott B Swarbreck, Dan Secor, Christopher G Ellis, Michael D Sharpe, John X Wilson, Karel Tyml

Medical Biophysics Publications

The microcirculation during sepsis fails due to capillary plugging involving microthrombosis. We demonstrated that intravenous injection of ascorbate reduces this plugging, but the mechanism of this beneficial effect remains unclear. We hypothesize that ascorbate inhibits the release of the antifibrinolytic plasminogen activator inhibitor-1 (PAI-1) from endothelial cells and platelets during sepsis. Microvascular endothelial cells and platelets were isolated from mice. Cells were cultured and stimulated with lipopolysaccharide (LPS), tumor necrosis factor alpha (TNFα), or thrombin (agents of sepsis), with/without ascorbate for 1-24 h. PAI-1 mRNA was determined by quantitative PCR. PAI-1 protein release into the culture medium was measured by …

Dynamic Perfusion Ct In Brain Tumors., Timothy Pok Chi Yeung, Glenn Bauman, Slav Yartsev, Enrico Fainardi, David Macdonald, Ting-Yim Lee

Medical Biophysics Publications

Dynamic perfusion CT (PCT) is an imaging technique for assessing the vascular supply and hemodynamics of brain tumors by measuring blood flow, blood volume, and permeability-surface area product. These PCT parameters provide information complementary to histopathologic assessments and have been used for grading brain tumors, distinguishing high-grade gliomas from other brain lesions, differentiating true progression from post-treatment effects, and predicting prognosis after treatments. In this review, the basic principles of PCT are described, and applications of PCT of brain tumors are discussed. The advantages and current challenges, along with possible solutions, of PCT are presented.

The Dissociable Effects Of Punishment And Reward On Motor Learning, Joseph M. Galea, Elizabeth Mallia, John Rothwell, Jorn Diedrichsen

Brain and Mind Institute Researchers' Publications

A common assumption regarding error-based motor learning (motor adaptation) in humans is that its underlying mechanism is automatic and insensitive to reward- or punishment-based feedback. Contrary to this hypothesis, we show in a double dissociation that the two have independent effects on the learning and retention components of motor adaptation. Negative feedback, whether graded or binary, accelerated learning. While it was not necessary for the negative feedback to be coupled to monetary loss, it had to be clearly related to the actual performance on the preceding movement. Positive feedback did not speed up learning, but it increased retention of the …

Proteomic Signature Of The Murine Intervertebral Disc, Matthew R. Mccann, Priya Patel, Agya Frimpong, Yizhi Xiao, Walter L. Siqueira, Cheryle A. Séguin

Bone and Joint Institute

© 2015 McCann et al. Low back pain is the most common musculoskeletal problem and the single most common cause of disability, often attributed to degeneration of the intervertebral disc. Lack of effective treatment is directly related to our limited understanding of the pathways responsible for maintaining disc health. While transcriptional analysis has permitted initial insights into the biology of the intervertebral disc, complete proteomic characterization is required. We therefore employed liquid chromatography electrospray ionization tandem mass spectrometry (LC-ESI-MS/MS) protein/peptide separation and mass spectrometric analyses to characterize the protein content of intervertebral discs from skeletally mature wild-type mice. A total …