A5002500072- Heart Rate Variability and Autonomic Control
- Cardiovascular Health and Disease Prevention
- Birth, Development, and Health
- Cardiovascular and exercise physiology
- Obesity, Physical Activity, Diet
- Blood Pressure and Hypertension Studies
- Cardiovascular Disease and Adiposity
- Cardiovascular Syncope and Autonomic Disorders
- Non-Invasive Vital Sign Monitoring
- Stress Responses and Cortisol
- Child Abuse and Trauma
- Cardiac Arrest and Resuscitation
- Children's Physical and Motor Development
- Spaceflight effects on biology
- Cardiovascular Function and Risk Factors
- Neuroscience of respiration and sleep
- Child and Adolescent Psychosocial and Emotional Development
- Thermoregulation and physiological responses
- ECG Monitoring and Analysis
- Nutritional Studies and Diet
- Sports injuries and prevention
- Cerebrovascular and Carotid Artery Diseases
- Anesthesia and Neurotoxicity Research
- Perfectionism, Procrastination, Anxiety Studies
- Infrared Thermography in Medicine
Brock University
2015-2024
Niagara Health System
2023
Department of Medical Sciences
2018
Northumbria University
2018
Western University
2003-2005
University of Waterloo
1999-2004
McMaster University
1996-1998
Natural Sciences and Engineering Research Council
1996
The purpose of the present study was to determine cortical structures involved with integrated baroreceptor-mediated modulation autonomic cardiovascular function in conscious humans independent changes arterial blood pressure. We assessed brain regions associated lower body negative pressure (LBNP)-induced baroreflex control using functional magnetic resonance imaging oxygen level-dependent (BOLD) contrast eight healthy male volunteer subjects. levels LBNP administered were 5, 15 and 35...
Adverse childhood experiences (ACEs), such as abuse, household dysfunction, and neglect, have been shown to increase adults' risk of developing chronic conditions factors for conditions, including cardiovascular disease (CVD). Much less work has investigated the effect ACEs on children's physical health status that may lead adult conditions. Therefore, present study examined relationship between early disease.1 234 grade six eight students participated in school-based data collection, which...
Considerable evidence links dietary salt intake with the development of hypertension, left ventricular hypertrophy, and increased risk stroke coronary heart disease. Despite extensive epidemiological basic science interrogation relationship between high (HS) blood pressure, it remains unclear how HS impacts endothelial cell (EC) vascular structure in vivo. This study aims to elucidate HS-induced pathology using a differential systemic decellularization vivo approach.We performed systematic...
We tested the hypothesis that kinetics of O 2 uptake (V˙o ) measured in transition to exercise near or above peakV˙o peak would be slower than those for subventilatory threshold exercise. Eight healthy young men exercised at ∼57, ∼96, and ∼125%V˙o . Data were fit by a two- three-component exponential model with semilogarithmic transformation difference between required V˙o measuredV˙o With model, phase appeared faster 125% [time constant (τ = 16.3 ± 8.8 (SE) s] 57%V˙o 29.4 4.0 s) but not...
O’Leary, Deborah D., Karen Hope, and Digby G. Sale.Posttetanic potentiation of human dorsiflexors. J. Appl. Physiol. 83(6): 2131–2138, 1997.—Twitch contractions the ankle dorsiflexors were evoked before after applied 7-s tetanic stimulation at 100 Hz in 20 young adults. Torque decreased 15% during tetanus. At 5 s tetanus, twitch peak torque had potentiated 45%. Potentiation declined to 28% 1 min, rose slightly 33% 2 slowly with still 25% min. There was large intersubject variation amount...
Cerebrovascular autoregulation has been described with a phase lead of cerebral blood flow preceding changes in perfusion pressure (CPP), but there less focus on the effect CPP vascular resistance. We investigated these relations during spontaneous fluctuations (control) and repeated head-up tilt.Eight healthy adults were studied supine rest tilt 10-second supine, 10 seconds at 45 degrees for total 12 cycles. Cerebral was estimated from mean velocity (MFV) by transcranial Doppler ultrasound,...
The purpose of this study was to determine the effect baroreceptor unloading on sensitivity cardiovagal and sympathetic arms baroreflex during upright posture. Beat‐by‐beat R‐R interval, arterial blood pressure cardiac output (Doppler ultrasound), as well muscle nerve activity (MSNA) were recorded periods in supine (Supine) 60 deg head‐up tilt (HUT) positions (n = 8 volunteers). Cardiovagal (BRS) measured by spontaneous sequence analysis method using systolic while BRS determined slope...
Orthostatic intolerance follows actual weightlessness and simulated by bed rest. Orthostasis immediately after acute exercise imposes greater cardiovascular stress than orthostasis without prior exercise. We hypothesized that 5 min/day of [supine lower body negative pressure (LBNP)] following LBNP maintains orthostatic tolerance during Identical twins (14 women, 16 men) underwent 30 days 6° head-down tilt One each pair was randomly selected as a control, their sibling performed 40 treadmill...
Low baroreflex sensitivity (BRS) and heart rate variability (HRV) are associated with the pathogenesis of adult hypertension. However, limited information exists about negative consequences elevated childhood blood pressure (BP) autonomic regulation. Additionally, there developmental changes in regulation throughout puberty, yet studies have not appropriately accounted for this. The objective this study was to investigate BRS HRV children 2 different BP profiles, while controlling effects...
In this study, we tested the hypothesis that carotid arteries undergo rapid changes in distensibility on moving from supine to head-up tilt (HUT) postures and, subsequently, change (cDa) might be associated with concurrent reductions cardiovagal baroreflex sensitivity (BRS). Thus effect of posture vascular mechanics and BRS consideration for altered central hemodynamics (i.e., stroke volume; Doppler ultrasound) was examined. Carotid pulse pressure (cPP; Millar transducer) contralateral...
Cardiovagal baroreflex sensitivity (cvBRS) measures the efficiency of cardiovagal to modulate heart rate in response increases or decreases systolic blood pressure (SBP). Given that baroreceptors are located walls carotid sinuses (CS) and aortic arch (AA), arterial mechanics these sites important contributors cvBRS. However, relative contribution CS AA cvBRS remains unclear. This study employed sex differences as a model test hypothesis between groups would be explained by vascular but not...
Introduction Recent reviews have found substantial links between a toxic childhood environment including child abuse and severe household dysfunction adult cardiovascular disease (CVD). Collectively referred to as adverse experiences (ACEs), this is prevalent among children, with recent Canadian estimates of at 27%–32%, 49%. Based on these prevalence rates, the potential effect ACEs CVD more significant than previously thought. Yet, how amplify risk for later remains unclear. Lifestyle...
Adverse childhood experiences (ACEs) are associated with dysregulation of inflammation and cortisol. The objectives this study were to use principal component analysis explore the inflammatory biomarker data create composite variables; examine relationship between these measures ACEs cortisol; assess whether relationships moderated by sex. included 232 young adults from Niagara Longitudinal Heart Study (NLHS). After adjusting for covariates, higher exposure significantly predicted low-grade...
The COVID-19 pandemic has been linked to poor mental health outcomes and may be particularly damaging for young adults who more affected by governmental responses such as mandatory school work closures, online schooling, social isolation. Exposure Adverse Childhood Experiences (ACEs) also shown have a significant impact on among adults. This prospective study examined whether with higher ACE profiles were vulnerable stressors. Using pre-COVID-19 data from the Niagara Longitudinal Heart Study...
Abstract Aging results from the accumulation of molecular damage that impairs normal biochemical processes. We previously reported age‐linked to amino acid sequence NGR (Asn‐Gly‐Arg) in “gain‐of‐function” conformational switching isoDGR (isoAsp‐Gly‐Arg). This integrin‐binding motif activates leukocytes and promotes chronic inflammation, which are characteristic features cardiovascular disorders. now report anti‐isoDGR immunotherapy mitigates lifespan reduction Pcmt1 −/− mouse. observed...
Beat-by-beat estimates of total peripheral resistance (TPR) can be obtained from continuous measurements cardiac output by using Doppler ultrasound and noninvasive mean arterial blood pressure (MAP). We employed transfer function analysis to study the heart rate (HR) vascular response spontaneous changes in relationships systolic (SBP) HR (SBP-->HR), MAP cerebrovascular index (CVRi) (MAP-->TPR MAP-->CVRi), as well stroke volume (SV) TPR nine healthy subjects supine 45 degrees head-up tilt...
This study tested the hypothesis that cardiovascular and hormonal responses to lower body negative pressure (LBNP) would be altered by 4-h head down bed rest (HDBR) in 11 healthy young men. In post-HDBR testing, three subjects failed finish protocol due presyncopal symptoms, heart rate was increased during LBNP compared with pre-HDBR, mean arterial blood elevated at 0, -10, -20 mmHg reduced -40 mmHg, central venous (CVP) cardiac stroke volume were all levels of LBNP. Plasma concentrations...
Key points Reductions in cerebral blood flow (CBF) may be implicated the development of neuromuscular fatigue; however, contribution from hypocapnic‐induced reductions (i.e. ) CBF versus per se has yet to isolated. We assessed function while using indomethacin selectively reduce without changes and controlled hyperventilation‐induced hypocapnia both . Increased corticospinal excitability appears exclusive but not CBF, whereas sub‐optimal voluntary output motor cortex is moderately associated...
Elevated blood pressure (BP) in adults is associated with increased arterial stiffness and thickness; however, its effect on health a pediatric population less understood. The purpose of this study was to identify the relationship between childhood BP markers arteriosclerotic progression. consisted 106 children across wide range values divided into 2 groups: high (HBP; ≥95th percentile; n = 21) normal (NBP; <90th 85) based consistent automated measures taken at time points. laboratory...
Twitch contractions of the ankle dorsiflexors were evoked before and after 7 s tetanic stimulation at 100 Hz in young women men. Torque decreased more men (18%) than (12%) during tetanus. There was no gender difference twitch peak torque potentiation over 5-min post-tetanus. Potentiation 42% (women) 45% (men) 5 post-tetanus, still present min (women 24%, 25%). The immediate (5 s) shortening rise time similar (14%) (13%), but men's came to exceed whereas women's only approached pretetanus...