A5032070901- Cardiovascular Health and Disease Prevention
- Traumatic Brain Injury and Neurovascular Disturbances
- Heart Rate Variability and Autonomic Control
- Cardiovascular and exercise physiology
- Traumatic Brain Injury Research
- Optical Imaging and Spectroscopy Techniques
- High Altitude and Hypoxia
- Cardiovascular and Diving-Related Complications
- Cerebrovascular and Carotid Artery Diseases
- Cardiac Arrest and Resuscitation
- Thermoregulation and physiological responses
- Neuroscience of respiration and sleep
- Sports Performance and Training
- Blood Pressure and Hypertension Studies
- Intracranial Aneurysms: Treatment and Complications
- Nitric Oxide and Endothelin Effects
- Apelin-related biomedical research
- Neural and Behavioral Psychology Studies
- Acute Ischemic Stroke Management
- Blood properties and coagulation
- Advanced MRI Techniques and Applications
- Climate Change and Health Impacts
- Sports injuries and prevention
- Venous Thromboembolism Diagnosis and Management
- Injury Epidemiology and Prevention
University of South Wales
2016-2025
Okanagan University College
2013
University of British Columbia
2013
Toyo University
2013
Age-related impairments in cerebral blood flow and cerebrovascular reactivity to carbon dioxide (CVRCO2) are established risk factors for stroke that respond favorably aerobic training. The present study examined what extent hemodynamics improved when training is sustained throughout the adult lifespan.Eighty-one healthy males were prospectively assigned 1 of 4 groups based on their age (young, ≤30 years versus old, ≥60 years) lifetime physical activity levels (trained, ≥150 minutes...
The present study examined to what extent professional boxing compromises cerebral haemodynamic function and its association with CTBI (chronic traumatic brain injury). A total of 12 male boxers were compared age-, gender- physical fitness-matched non-boxing controls. We assessed dCA (dynamic autoregulation; thigh-cuff technique transfer analysis), CVRCO2 (cerebrovascular reactivity changes in CO2: 5% CO2 controlled hyperventilation), orthostatic tolerance (supine standing) neurocognitive...
Chronic mountain sickness (CMS) is a maladaptation syndrome encountered at high altitude (HA) characterised by severe hypoxaemia that carries higher risk of stroke and migraine associated with increased morbidity mortality. We examined if exaggerated oxidative-inflammatory-nitrosative stress (OXINOS) corresponding decrease in vascular nitric oxide bioavailability patients CMS (CMS+) impaired cerebrovascular function adverse neurological outcome. Systemic OXINOS was markedly elevated CMS+...
Elevated cardiorespiratory fitness improves resting cerebral perfusion, although to what extent this is further amplified during acute exposure exercise stress and the corresponding implications for oxygenation remain unknown. To examine this, we recruited 12 moderately active sedentary healthy males. Middle artery blood velocity (MCAv) prefrontal cortical oxyhemoglobin (cO 2 Hb) concentration were monitored continuously at rest throughout an incremental cycling test exhaustion. Despite a...
To what extent sildenafil, a selective inhibitor of the type-5 phosphodiesterase modulates systemic redox status and cerebrovascular function during acute exposure to hypoxia remains unknown. address this, 12 healthy males (aged 24 ± 3 y) participated in randomized, placebo-controlled crossover study involving both normoxia (60 min) (FiO2 = 0.14), followed by oral administration 50 mg sildenafil placebo (double-blinded). Venous blood was sampled for ascorbate radical (A•-: electron...
What is the topic of this review? The review to consider innovative exercise strategies that optimize neuroprotection in order combat cognitive decline and neurodegenerative disease older age. advances does it highlight? summarizes current understanding around mode, duration, frequency intensity, then highlights adaptive roles select stressors have equal if not indeed greater capacity than per se induce health-related adaptation brain. These include, but are exclusively limited to,...
New Findings What is the central question of this study? How does recurrent contact incurred across a season professional rugby union impact molecular, cerebrovascular and cognitive function? main findings its importance? A single increases systemic oxidative–nitrosative stress (OXNOS) confirmed by free radical‐mediated suppression in nitric oxide bioavailability. Forwards encountered higher frequency events compared to backs, exhibiting elevated OXNOS lower function cognition. Collectively,...
Cardiorespiratory fitness is thought to have beneficial effects on systemic vascular health, in part, by decreasing arterial stiffness. However, the absence of non-invasive methods, it remains unknown whether this effect extends cerebrovasculature. The present study uses a novel pulsed spin labelling (pASL) technique explore relationship between cardiorespiratory and compliance middle cerebral arteries (MCAC). Other markers cerebrovascular including resting blood flow (CBF) reactivity CO 2...
Chronic mountain sickness (CMS) is a high-altitude (HA) maladaptation syndrome characterised by elevated systemic oxidative-nitrosative stress (OXNOS) due to free radical-mediated reduction in vascular nitric oxide (NO) bioavailability. To better define underlying mechanisms and consequences, this study compared healthy male lowlanders (80 m, n = 10) against age/sex-matched highlanders born bred La Paz, Bolivia (3600 m) with (CMS+, without (CMS-, CMS. Cephalic venous blood was assayed using...
Abstract Following retirement from sport, the chronic consequences of prior‐recurrent contact are evident and retired rugby union players may be especially prone to accelerated cognitive decline. The present study sought integrate molecular, cerebrovascular biomarkers in with concussion history. Twenty aged 64 ± 5 years three (interquartile range (IQR), 3) concussions incurred over 22 (IQR, 6) were compared 21 sex‐, age‐, cardiorespiratory fitness‐ education‐matched controls no prior...
Key points In vitro evidence has identified that coagulation is activated by increased oxidative stress, though the link and underlying mechanism in humans have yet to be established. We conducted first randomised controlled trial healthy participants examine if oral antioxidant prophylaxis alters haemostatic responses hypoxia exercise given their synergistic capacity promote free radical formation. Systemic formation was shown increase during further compounded exercise, were attenuated...
Abstract Hypoxia has the potential to impair cognitive function; however, it is still uncertain which domains are adversely affected. We examined effects of acute hypoxia (∼7 h) on central executive (Go/No‐Go) and non‐executive (memory) tasks extent impairment was potentially related regional cerebral blood flow oxygen delivery (CDO 2 ). Twelve male participants performed following 0, 2, 4 6 h passive exposure both normoxia (12% O ), in a randomized block cross‐over single‐blinded design....
Carotid endarterectomy (CEA) is a surgical procedure to remove stenotic atherosclerotic plaque from the origin of carotid artery reduce risk major stroke. Its impact on postoperative cognitive function (POCF) remains controversial; complicated, in part, by traditional failure account for practice effects incurred during consecutive psychometric testing. To address this first time, we performed testing (learning and memory, working attention information processing, visuomotor coordination) 15...
Post-prandial hyperlipidaemia (PPH) acutely impairs systemic vascular endothelial function, potentially attributable to a free radical-mediated reduction in nitric oxide (NO) bioavailability (oxidative-nitrosative stress). However, it remains be determined whether this extends the cerebrovasculature. To examine this, 38 (19 young (≤35 years) and 19 aged (≥60 years)) healthy males were recruited. Cerebrovascular function (middle cerebral artery velocity, MCAv) cerebrovascular reactivity...
Recurrent contact and concussion in rugby union remains a significant public health concern given the potential increased risk of neurodegeneration later life. This study determined to what extent prior‐recurrent impacts molecular‐hemodynamic biomarkers underpinning cognition current professional players with history concussion. Measurements were performed 20 an average 16 (interquartile range [IQR] 13–19) years playing reporting 3 (IQR 1–4) concussions. They compared 17 sex‐age‐physical...
Football players are at increased risk of neurodegeneration, the likely consequence repetitive mechanical trauma caused by heading ball. However, to what extent a history ball affects cerebral blood flow (CBF) regulation and its potential relationship cognitive impairment is unknown. To address this, we recruited 16 concussion‐free male amateur football (age: 25 ± 6 y) with (18 18 sex, age, education, activity‐matched controls no prior contact sport participation or concussion. Cerebral...
We examined the acute impact of both low- and high-glycemic index (GI) breakfasts on plasma brain-derived neurotrophic factor (BDNF) dynamic cerebral autoregulation (dCA) compared with breakfast omission. Ten healthy men (age 24 ± 1 yr) performed three trials in a randomized crossover order; omission Low-GI (GI = 40) High-GI 71) conditions. Middle artery velocity (transcranial Doppler ultrasonography) arterial pressure (finger photoplethysmography) were continuously measured for 5 min before...
What is the central question of this study? To what extent do hypoxia-induced changes in peripheral and respiratory chemoreflex modulate anterior posterior cerebral oxygen delivery, with corresponding implications for susceptibility to acute mountain sickness? main finding its importance? We provide evidence site-specific regulation blood flow hypoxia that preserves delivery but not circulation, minimal contribution from chemoreflex. External carotid artery vasodilatation might prove be an...
Introduction Concussion is regularly observed in rugby union and has generated a growing public health concern, yet remains one of the least understood injuries facing sports medicine community. Evidence suggests that multiple concussions may increase susceptibility to long-term neurological complications present decades after initial injury for reasons remain unclear. We aimed determine incidence rate risk factors concussion amongst community-level union-15s players active during 1980s...
Abstract Emergent evidence suggests that cyclic intermittent hypoxia increases cerebral arterial shear rate and endothelial function, whereas continuous exposure decreases anterior oxygen (O 2 ) delivery. To examine to what extent impacts rate, consequent O delivery (CDO ), eight healthy males were randomly assigned single-blind 7 h passive both normoxia (21% (12% ). Blood flow in the brachial internal carotid arteries determined using Duplex ultrasound included combined assessment of...