Publications by authors named "Prorok J"

Introduction: Strategic knowledge mobilization efforts are needed to enhance uptake and use of the Canadian 24-Hour Movement Guidelines (24HMG), which describe optimal amounts of physical activity, sedentary behaviour and sleep each day for overall health. The Whole Day Matters Toolkit for Primary Care is an evidence-informed resource to help primary care providers (PCPs) disseminate the 24HMGs. The purpose of this study was to describe gaining consensus on toolkit components through iterative revisions to improve its utility in preparation for the September 2022 launch, and to summarize early dissemination efforts.

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This paper describes a pluralistic framework to inform transformative change across community and healthcare domains to optimize the mental health of older adults in support of healthy ageing. An extensive review and analysis of the literature informed the creation of a framework that contextualizes the priority areas of the WHO Decade of Health Ageing (ageism, age-friendly environments, long-term care, and integrated care) with respect to older adult mental health. The framework additionally identifies barriers, facilitators, and strategies for action at macro (social/system), meso (services/supports), and micro (older adults) levels of influence.

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Establishing intervention effectiveness is an important component of a broader knowledge translation (KT) process. However, mobilizing the implementation of these interventions into practice is perhaps the most important aspect of the KT cycle. The purpose of the current study was to conduct an umbrella review to (a) identify promising interventions for SI&L in older adults, (b) interpret (translate) the findings to inform clinical knowledge and practice interventions in different settings and contexts, and (c) highlight research gaps that may hinder the uptake of these interventions in practice.

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Recent experimental data shows that hesperetin, a citrus flavonoid, affects potassium channels and can prolong the QT interval in humans. Therefore, in the present study we investigated the effects of hesperetin on various transmembrane ionic currents and on ventricular action potentials. Transmembrane current measurements and action potential recordings were performed by patch-clamp and the conventional microelectrode techniques in dog and rabbit ventricular preparations.

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The present study was designed to test the hypothesis that the selectivity of blocking the late Na current (I) over the peak Na current (I) is related to the fast offset kinetics of the Na channel inhibitor. Therefore, the effects of 1 µM GS967 (I inhibitor), 20 µM mexiletine (I/B antiarrhythmic) and 10 µM quinidine (I/A antiarrhythmic) on I and I were compared in canine ventricular myocardium. I was estimated as the maximum velocity of action potential upstroke (V).

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Background: Canada's 24-Hour Movement Guidelines for Adults have shifted the focus from considering movement behaviours (i.e., physical activity, sedentary behaviour, and sleep) separately to a 24-h paradigm, which considers how they are integrated.

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The health benefits of regular physical exercise are well known. Even so, there is increasing evidence that the exercise regimes of elite athletes can evoke cardiac arrhythmias including ventricular fibrillation and even sudden cardiac death (SCD). The mechanism of exercise-induced arrhythmia and SCD is poorly understood.

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Besides the health benefits of regular exercise, high-level training-above an optimal level-may have adverse effects. In this study, we investigated the effects of long-term vigorous training and its potentially detrimental structural-functional changes in a small animal athlete's heart model. Thirty-eight 4-month-old male guinea pigs were randomized into sedentary and exercised groups.

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Article Synopsis
  • Canada's aging population faces increased risk of chronic conditions and frailty, leading to challenges in daily activities and recovery from illnesses.
  • The Canadian Frailty Network launched the AVOID Frailty campaign to help evaluate and reduce factors that contribute to frailty among older adults.
  • An Enabling Healthy Aging Symposium gathered 36 stakeholders to discuss important community-level challenges and opportunities for implementing the campaign, resulting in actionable recommendations to promote healthy aging.
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Background: Despite increased recognition of frailty and its importance, high quality evidence to guide decision-making is lacking. There has been variation in reported data elements and outcomes which makes it challenging to interpret results across studies as well as to generalize research findings. The creation of a frailty core set, consisting of a minimum set of data elements and outcomes to be measured in all frailty studies, would allow for findings from research and translational studies to be collectively analyzed to better inform care and decision-making.

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Background: We developed clinical practice guidelines to provide health care providers with evidence-based recommendations for decisions related to the effective management of frailty and pre-frailty using nutrition and physical activity interventions.

Methods: We based the recommendations on two systematic reviews with meta-analyses. Nutrition, physical activity, and combined nutrition and physical activity interventions for adults ≥65y were considered if study populations were identified as frail using a frailty tool or assessment.

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Background And Purpose: The aim of the present study was to study the antiarrhythmic effects and cellular mechanisms of desethylamiodarone (DEA), the main metabolite of amiodarone (AMIO), following acute and chronic 4-week oral treatments (25-50 mg·kg ·day ).

Experimental Approach: The antiarrhythmic effects of acute iv. (10 mg·kg ) and chronic oral (4 weeks, 25 mg·kg ·day ) administration of DEA were assessed in carbachol and tachypacing-induced dog atrial fibrillation models.

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Enhancement of the late sodium current (I) increases arrhythmia propensity in the heart, whereas suppression of the current is antiarrhythmic. In the present study, we investigated I in canine ventricular cardiomyocytes under action potential voltage-clamp conditions using the selective Na channel inhibitors GS967 and tetrodotoxin. Both 1 µM GS967 and 10 µM tetrodotoxin dissected largely similar inward currents.

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Cannabis use is associated with known cardiovascular side effects such as cardiac arrhythmias or even sudden cardiac death. The mechanisms behind these adverse effects are unknown. The aim of the present work was to study the cellular cardiac electrophysiological effects of cannabidiol (CBD) on action potentials and several transmembrane potassium currents, such as the rapid (I) and slow (I) delayed rectifier, the transient outward (I) and inward rectifier (I) potassium currents in rabbit and dog cardiac preparations.

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Enhancement of the late Na current (I) increases arrhythmia propensity in the heart, while suppression of the current is antiarrhythmic. GS967 is an agent considered as a selective blocker of I. In the present study, effects of GS967 on I and action potential (AP) morphology were studied in canine ventricular myocytes by using conventional voltage clamp, action potential voltage clamp and sharp microelectrode techniques.

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Sudden cardiac death among top athletes is very rare, however, it is 2-4 times more frequent than in the age-matched control population. In the present study, the electrophysiological consequences of long-term exercise training were investigated on Ca homeostasis and ventricular repolarization, together with the underlying alterations of ion channel expression, in a rat athlete's heart model. 12-week swimming exercise-trained and control Wistar rats were used.

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Cannabis use is associated with cardiovascular adverse effects ranging from arrhythmias to sudden cardiac death. The exact mechanism of action behind these activities is unknown. The aim of our work was to study the effect of cannabidiol (CBD), tetrahydrocannabinol and 11-nor-9-carboxy-tetrahydrocannabinol on cellular cardiac electrophysiological properties including ECG parameters, action potentials, hERG and I ion channels in HEK cell line and in rabbit and guinea pig cardiac preparations.

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Ibuprofen is a widely used nonsteroidal anti-inflammatory drug, which has recently been associated with increased cardiovascular risk, but its electrophysiological effects have not yet been properly studied in isolated cardiac preparations. We studied the effects of ibuprofen on action potential characteristics and several transmembrane ionic currents using the conventional microelectrode technique and the whole-cell configuration of the patch-clamp technique on cardiac preparations and enzymatically isolated ventricular myocytes. In dog (200 µM;  = 6) and rabbit (100 µM;  = 7) papillary muscles, ibuprofen moderately but significantly prolonged repolarization at 1 Hz stimulation frequency.

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Background: The number of older adults with complex health needs in Ontario is growing. The Ministry of Health and Long-Term Care requested a resource mapping project to assess the current 2018 and projected 2025 number of specialist physician resources.

Methods: Geriatric specialist physicians were defined as geriatricians, geriatric psychiatrists, and Care of the Elderly (COE) physicians.

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With aging populations around the world, frailty is becoming more prevalent increasing the need for health systems and social systems to deliver optimal evidence based care. However, in spite of the growing number of frailty publications, high-quality evidence for decision making is often lacking. Inadequate descriptions of the populations enrolled including frailty severity and frailty conceptualization, lack of use of validated frailty assessment tools, utilization of different frailty instruments between studies, and variation in reported outcomes impairs the ability to interpret, generalize and implement the research findings.

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Article Synopsis
  • The study investigates how the Na/Ca exchanger (NCX) interacts with other ion channels in spontaneous heart pacemaking, focusing on its role using a new selective inhibitor, ORM-10962, on rabbit sinoatrial node cells.
  • Researchers used patch-clamp techniques to measure electrical currents, monitored calcium transients, and recorded action potentials to assess the impact of NCX on heart rhythm.
  • Results show that NCX has a crucial role in maintaining stable cardiac pacemaking, and its interaction with other currents can help compensate for disruptions, suggesting a robust mechanism for heart rhythm regulation.
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We have evidence that the intravenous infusion of sodium nitrite (NaNO) results in an antiarrhythmic effect when given 24 h prior to an ischemia and reperfusion (I/R) insult in anaesthetized dogs. This protection was associated with the reduction of reactive oxygen species resulting from I/R through the attenuation of mitochondrial respiration. Here, we examined whether the changes in calcium, which also contributes to arrhythmia generation, play a role in the NaNO-induced effect.

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Our goal was to study whether glycerol and xylitol provide protection against osmotic stress in keratinocytes. The experiments were performed on HaCaT keratinocytes. Hyperosmotic stress was induced by the addition of sorbitol (450, 500 and 600 mOsm).

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