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Chili Pepper Consumption And Cardiovascular Mortality, J. David Spence

Department of Medicine Publications

No abstract provided.

Trimethylamine N-Oxide: Not Just Red Meat - Egg Yolk And Renal Function Are Also Important, J. David Spence

Department of Medicine Publications

No abstract provided.

Registration Of Amiloride In South Africa: Cutting The Gordian Knot, B. L. Rayner, J. D. Spence, A. Bryer, M. T. Mpe

Department of Medicine Publications

Amiloride is an antagonist of the renal tubular epithelial sodium channel (ENaC). As such, it is a diuretic that is both potassium and magnesium sparing. It is used for the treatment of potassium depletion and hypertension, and is the specific therapy for hypertension due to overactivity of the ENaC (Liddle syndrome and several additional genetic causes of the Liddle phenotype - low renin and low aldosterone). It is listed as a World Health Organization essential drug, but has never been registered in South Africa (SA) and can therefore only be prescribed under a Section 21 application to the SA Health …

Deep Learning-Based Carotid Media-Adventitia And Lumen-Intima Boundary Segmentation From Three-Dimensional Ultrasound Images, Ran Zhou, Aaron Fenster, Yujiao Xia, J. David Spence, Mingyue Ding

Department of Medicine Publications

Purpose: Quantification of carotid plaques has been shown to be important for assessing as well as monitoring the progression and regression of carotid atherosclerosis. Various metrics have been proposed and methods of measurements ranging from manual tracing to automated segmentations have also been investigated. Of those metrics, quantification of carotid plaques by measuring vessel-wall-volume (VWV) using the segmented media-adventitia (MAB) and lumen-intima (LIB) boundaries has been shown to be sensitive to temporal changes in carotid plaque burden. Thus, semi-automatic MAB and LIB segmentation methods are required to help generate VWV measurements with high accuracy and less user interaction. Methods: In …

Pioglitazone Therapy In Patients With Stroke And Prediabetes: A Post Hoc Analysis Of The Iris Randomized Clinical Trial, J. David Spence, Catherine M. Viscoli, Silvio E. Inzucchi, Jennifer Dearborn-Tomazos, Gary A. Ford, Mark Gorman, Karen L. Furie, Anne M. Lovejoy, Lawrence H. Young, Walter N. Kernan

Department of Medicine Publications

Importance: In the Insulin Resistance Intervention After Stroke (IRIS) randomized clinical trial, pioglitazone, an insulin-sensitizing agent, reduced the risk for recurrent stroke or myocardial infarction (MI) among patients with insulin resistance. However, insulin resistance is not commonly measured in clinical practice. Objective: To analyze the effects of pioglitazone in patients with good adherence as well as intention-to-treat effects of pioglitazone in patients with prediabetes in the IRIS trial. Design, Setting, and Participants: The IRIS trial was a randomized multicenter clinical trial in patients with prior stroke or transient ischemic attack as well as insulin resistance but not diabetes. Patients were …

Perioperative Venous Thromboembolism Prophylaxis In Prostate Cancer Surgery, Zachary Klaasson, Christopher J.D. Wallis, Luke T. Lavallee, Philippe D. Violette

Department of Medicine Publications

Purpose

To describe a patient and procedure specific approach to selecting Venous thromboembolism (VTE) prophylaxis for men who undergo radical prostatectomy.

Methods

We performed a literature search and narrative review of VTE after radical prostatectomy. We describe the current paradigm of perioperative thromboprophylaxis and underlying rationale. Relevant findings from the European Association of Urology thromboprophylaxis guidelines are interpreted and summarized.

Results

The use of extended post-operative thromboprophylaxis for patients who undergo radical prostatectomy is appropriate when the risk of symptomatic VTE outweighs the risk of major bleeding. Patient and procedure factors impact VTE risk. Patient risk can be stratified as …

Antiplatelet Therapy In Ischemic Stroke And Transient Ischemic Attack: An Overview Of Major Trials And Meta-Analyses, Daniel G. Hackam, J. David Spence

Department of Medicine Publications

No abstract provided.

Nutrition And Risk Of Stroke, J. David Spence

Department of Medicine Publications

Nutrition is far more important in stroke risk than most physcians suppose. Healthy lifestyle choices reduce the risk of stroke by ~80%, and of the factors that increase the risk of stroke, the worst is diet: only ~0.1% of Americans consume a healthy diet, and only 8.3% consume a somewhat healthy diet. The situation is probably not much better in most other countries. A Cretan Mediterranean diet, high in olive oil, whole grains, fruits, vegetables and legumes, and low in cholesterol and saturated fat, can reduce stroke by 40% or more in high-risk patients. The role of the intestinal microbiome …

Pioglitazone For Prevention Of Cardiovascular Events In Patients With Stroke And Pre-Diabetes: Implications For Real-World Practice, J. David Spence

Department of Medicine Publications

No abstract provided.

Assessment Of A Novel 32-Channel Phased Array For Cardiovascular Hybrid Pet/Mri Imaging: Mri Performance., Adam Farag, R Terry Thompson, Jonathan D Thiessen, John Butler, Frank S Prato, Jean Theberge

Department of Medicine Publications

BACKGROUND: Cardiovascular imaging using hybrid positron emission tomography (PET) and magnetic resonance imaging (MRI) requires a radio frequency phased array resonator capable of high acceleration factors in order to achieve the shortest breath-holds while maintaining optimal MRI signal-to-noise ratio (SNR) and minimum PET photon attenuation. To our knowledge, the only two arrays used today for hybrid PET/MRI cardiovascular imaging are either incapable of achieving high acceleration or affect the PET photon count greatly.

PURPOSE: This study is focused on the evaluation of the MRI performance of a novel third-party prototype 32-channel phased array designed for simultaneous PET/MRI cardiovascular imaging. The …

The Threatful Self: Midbrain Functional Connectivity To Cortical Midline And Parietal Regions During Subliminal Trauma-Related Processing In Ptsd., Braeden A Terpou, Maria Densmore, Jean Theberge, Janine Thome, Paul Frewen, Margaret C Mckinnon, Ruth A Lanius

Department of Medicine Publications

BACKGROUND: The innate alarm system consists of a subcortical network of interconnected midbrain, lower brainstem, and thalamic nuclei, which together mediate the detection of evolutionarily-relevant stimuli. The periaqueductal gray is a midbrain structure innervated by the innate alarm system that coordinates the expression of defensive states following threat detection. In participants with post-traumatic stress disorder, the periaqueductal gray displays overactivation during the subliminal presentation of trauma-related stimuli as well as altered resting-state functional connectivity. Aberrant functional connectivity is also reported in post-traumatic stress disorder for the default-mode network, a large-scale brain network recruited during self-referential processing and autobiographical memory. Here, …

Back To The Basics: Resting State Functional Connectivity Of The Reticular Activation System In Ptsd And Its Dissociative Subtype., Janine Thome, Maria Densmore, Georgia Koppe, Braeden Terpou, Jean Theberge, Margaret C Mckinnon, Ruth A Lanius

Department of Medicine Publications

BACKGROUND: Brainstem and midbrain neuronal circuits that control innate, reflexive responses and arousal are increasingly recognized as central to the neurobiological framework of post-traumatic stress disorder (PTSD). The reticular activation system represents a fundamental neuronal circuit that plays a critical role not only in generating arousal but also in coordinating innate, reflexive responding. Accordingly, the present investigation aims to characterize the resting state functional connectivity of the reticular activation system in PTSD and its dissociative subtype.

METHODS: We investigated patterns of resting state functional connectivity of a central node of the reticular activation system, namely, the pedunculopontine nuclei, among individuals …

Overlapping Frontoparietal Networks In Response To Oculomotion And Traumatic Autobiographical Memory Retrieval: Implications For Eye Movement Desensitization And Reprocessing., Sherain Harricharan, Margaret C Mckinnon, Mischa Tursich, Maria Densmore, Paul Frewen, Jean Theberge, Bessel Van Der Kolk, Ruth A Lanius

Department of Medicine Publications

Background: Oculomotor movements have been shown to aid in the retrieval of episodic memories, serving as sensory cues that engage frontoparietal brain regions to reconstruct visuospatial details of a memory. Frontoparietal brain regions not only are involved in oculomotion, but also mediate, in part, the retrieval of autobiographical episodic memories and assist in emotion regulation. Objective: We sought to investigate how oculomotion influences retrieval of traumatic memories by examining patterns of frontoparietal brain activation during autobiographical memory retrieval in post-traumatic stress disorder (PTSD) and in healthy controls. Method: Thirty-nine participants (controls, n = 19; PTSD, n = 20) recollected both …

Vitamin B12 Deficiency And Hyperhomocysteinemia In Outpatients With Stroke Or Transient Ischemic Attack: A Cohort Study At An Academic Medical Centre, Shamon Ahmed, Chrysi Bogiatzi, Daniel G. Hackam, Angela C. Rutledge, Luciano A. Sposato, Alexander Khaw, Jennifer Mandzia, Mahmoud Reza Azarpazhoo, Vladimir Hachinski, J. David Spence

Department of Medicine Publications

Objective We sought to assess the current magnitude of the opportunity for secondary stroke prevention with B vitamins. Design A cohort study. Setting The Urgent TIA (Transient Ischaemic Attack) Clinic at an academic medical centre. Main outcome measures We assessed the prevalence of biochemical vitamin B 12 deficiency (B 12 Def, serum B 12 <156 pmol/L), hyperhomocysteinaemia (HHcy; plasma total homocysteine [tHcy] >14 μmol/L) and metabolic B 12 deficiency (MetB 12 Def, serum B 12 <258 pmol/L and HHcy) between 2002 and 2017, by age group and by stroke subtype. Results Data were available in 4055 patients. B 12 Def was present in 8.2% of patients overall; it declined from 10.9% of patients referred before 2009 to 5.4% thereafter (p=0.0001). MetB 12 Def was present in 10.6% of patients, and HHcy was present in 19.1% of patients. Among the patients aged ≥80 years, MetB 12 Def was present in 18.1% and HHcy in 35%. Among the 3410 patients whose stroke subtype was determined, HHcy was present in 18.4% of patients: 23.3% of large artery atherosclerosis, 18.1% of cardioembolic, 16.3% of small vessel disease, 10.8% of other unusual aetiologies and 13.6% of undetermined subtypes (p=0.0001). Conclusions Despite a decline in our referral area since 2009, B 12 Def, MetB 12 Def and HHcy remain common in patients with stroke/TIA. Because these conditions are easily treated and have serious consequences, all patients with stroke/TIA should have their serum B 12 and tHcy measured.

Increased Carotid Plaque Burden In Patients With Family Medical History Of Premature Cardiovascular Events In The Absence Of Classical Risk Factors, Paul W. Atkins, Hernán A. Perez, J. David Spence, Sonia E. Munoz, Luis J. Armando, Néstor H. García

Department of Medicine Publications

Introduction: The hypothesis that relates atherosclerosis to traditional risk factors (TRF) seems to be not as adequate as previously thought; other risk factors (RF) need to be considered to prevent atherosclerosis progression. Although a family medical history of premature cardiovascular events (FHx) has been considered the putative RF for decades, it has not been incorporated routinely into cardiovascular risk evaluation along with another RF. The objective of this study was to investigate whether FHx is associated with a higher atherosclerotic burden, measured as carotid total plaque area (TPA) in a population having no traditional RF. Material and methods: The study …

Blood Pressure Gradients In The Brain: Their Importance To Understanding Pathogenesis Of Cerebral Small Vessel Disease, J. David Spence

Department of Medicine Publications

The term “lacunar infarction” referred to small infarctions in the basal ganglia, internal capsule, thalamus, and brainstem, due to hypertensive small vessel disease. However, it has become common to refer to all small infarctions as “vascular centrencephalon”, where short straight arteries with few branches transmit high blood pressure straight through to end-arterioles. The cortex is supplied by long arteries with many branches, so there is a very large blood pressure gradient in the brain. When blood pressure in the brachial artery is 117/75 mmHg, the pressure in the lenticulostriate artery would be 113/73, and the pressure in small parietal arterioles …

Harm With High Levels Of Serum B12 In Elderly Persons, J. David Spence

Department of Medicine Publications

No abstract provided.