Paradoxical breathing during sleep is associated with increased sleep apnea and reduced ventilatory capacities in high-level spinal cord injury.

Sleep-disordered breathing is highly prevalent in individuals with high-level spinal cord injury. In addition, chest mechanics are known to be altered, leading to paradoxical breathing. Here we investigated the interaction between paradoxical breathing and sleep quality in these patients, and its association with measurements of respiratory function, hypercapnic ventilatory response and peak exercise ventilation.

Effect of histamine-receptor antagonism on the circulating inflammatory cell and cytokine response to exercise: A pilot study.

The purpose of this study was to gain insight into histamine's role in the exercise inflammatory response and recovery from exercise. To explore this, young healthy participants (n = 12) performed 300 eccentric leg extensions under control (Placebo) versus histamine H and H receptor antagonism (Blockade) in a randomized cross-over study. Circulating leukocytes and cytokines were measured for 72 h after exercise.

Nitric oxide-mediated vasodilation in human bone.

Objective: Regulation of blood flow to bone is critical but poorly understood, particularly in humans. This study aims to determine whether nitric oxide (NO), a major regulator of vascular tone to other tissues, contributes also to the regulation of blood flow to bone.

Methods: In young healthy adults (n = 16, 8F, 8M), we characterized NO-mediated vasodilation in the tibia in response to sublingual nitroglycerin and contrasted it to lower leg.

Exercise Training Does Not Attenuate Cardiac Atrophy or Loss of Function in Individuals With Acute Spinal Cord Injury: A Pilot Study.

Objective: To investigate the effects of 2 modes of exercise training, upper-body alone, and the addition of electrical stimulation of the lower body, to attenuate cardiac atrophy and loss of function in individuals with acute spinal cord injury (SCI).

Design: Randomized controlled trial.

Setting: Rehabilitation Hospital.

The effect of local passive heating on skeletal muscle histamine concentration: implications for exercise-induced histamine release.

Aerobic exercise induces mast cell degranulation and increases histamine formation by histidine decarboxylase, resulting in an ∼150% increase in intramuscular histamine. The purpose of this study was to determine if the increase in skeletal muscle temperature associated with exercise is sufficient to explain this histamine response. Specifically, we hypothesized that local passive heating that mimics the magnitude and time course of changes in skeletal muscle temperature observed during exercise would result in increased intramuscular histamine concentrations comparable to exercising values.

Telehealth: rapid adoption in community palliative care due to COVID-19: patient and professional evaluation.

Background/objective: The COVID-19 pandemic has brought the use of telehealth to the fore, as many people have been unable to interact directly with healthcare professionals (HCP). For community palliative care (CPC) services, this has meant a sudden change from a predominantly face-to-face model of care to one that incorporates telehealth. Understanding patient and HCP experiences with telehealth and how telehealth compares to 'usual' care will be crucial in planning future CPC services.

Quality of Life and Symptom Burden Improve in Patients Attending a Multidisciplinary Clinical Service for Cancer Cachexia: A Retrospective Observational Review.

Background: Cancer cachexia negatively affects quality of life (QoL) and increases symptom burden. A multimodal treatment approach may optimize cachexia outcomes, including QoL. We evaluated QoL and symptoms over time among patients attending a multidisciplinary clinical service for cancer cachexia.

Reductions in Cardiac Structure and Function 24 Months After Spinal Cord Injury: A Cross-Sectional Study.

Objective: To determine the alterations in cardiac structure and function that occur in the months after spinal cord injury (SCI).

Study Design: Cross-sectional SETTING: Rehabilitation Hospital PARTICIPANTS: Volunteers (N=29; 4 women, 25 men) between 3 and 24 months after SCI.

Main Outcome Measures: Transthoracic echocardiography was performed on each volunteer.

Prognostic Markers of Overall Survival in Cancer Patients Attending a Cachexia Support Service: An Evaluation of Clinically Assessed Physical Function, Malnutrition and Inflammatory Status.

Background: Cancer cachexia is a muscle-wasting syndrome that results in physical function impairments and decreased survival. While body weight and muscle mass loss predict survival, the prognostic significance of physical function in this population is unclear. Thus, we evaluated the association between physical function, and other routine measures, and overall survival (OS) in cancer patients attending a cachexia support service.

Effect of histamine-receptor antagonism on leg blood flow during exercise.

Histamine mediates vasodilation during inflammatory and immune responses, as well as following endurance exercise. During exercise, intramuscular histamine concentration increases, and its production, appears related to exercise intensity and duration. However, whether histamine contributes to exercise hyperemia and promotes exercise blood flow in an intensity- or duration-dependent pattern is unknown.

Effect of Time of Day on Sustained Postexercise Vasodilation Following Small Muscle-Mass Exercise in Humans.

Introduction: Previous studies observed diurnal variation in hemodynamic responses during recovery from whole-body exercise, with vasodilation appearing greater after evening versus morning sessions. It is unclear what mechanism(s) underlie this response. Since small muscle-mass exercise can isolate peripheral effects related to postexercise vasodilation, it may provide insight into possible mechanisms behind this diurnal variation.

Histamine-Receptor Antagonists Slow 10-km Cycling Performance in Competitive Cyclists.

Unlabelled: Histamine is released within skeletal muscle during exercise. In humans, antihistamines have no effect on speed, power output, or time-to-completion of short-duration high-intensity exercise. In mice, blocking histamine's actions decreases speed and duration of endurance tasks.

Mast cell degranulation and de novo histamine formation contribute to sustained postexercise vasodilation in humans.

In humans, acute aerobic exercise elicits a sustained postexercise vasodilation within previously active skeletal muscle. This response is dependent on activation of histamine H and H receptors, but the source of intramuscular histamine remains unclear. We tested the hypothesis that interstitial histamine in skeletal muscle would be increased with exercise and would be dependent on de novo formation via the inducible enzyme histidine decarboxylase and/or mast cell degranulation.

Post-exercise syncope: Wingate syncope test and visual-cognitive function.

Adequate cerebral perfusion is necessary to maintain consciousness in upright humans. Following maximal anaerobic exercise, cerebral perfusion can become compromised and result in syncope. It is unknown whether post-exercise reductions in cerebral perfusion can lead to visual-cognitive deficits prior to the onset of syncope, which would be of concern for emergency workers and warfighters, where critical decision making and intense physical activity are combined.

A single dose of histamine-receptor antagonists before downhill running alters markers of muscle damage and delayed-onset muscle soreness.

Histamine contributes to elevations in skeletal muscle blood flow following exercise, which raises the possibility that histamine is an important mediator of the inflammatory response to exercise. We examined the influence of antihistamines on postexercise blood flow, inflammation, muscle damage, and delayed-onset muscle soreness (DOMS) in a model of moderate exercise-induced muscle damage. Subjects consumed either a combination of fexofenadine and ranitidine (blockade, = 12) or nothing (control, = 12) before 45 min of downhill running (-10% grade).

Evidence of a broad histamine footprint on the human exercise transcriptome.

Key Points: Histamine is a primordial signalling molecule, capable of activating cells in an autocrine or paracrine fashion via specific cell surface receptors, in a variety of pathways that probably predate its more recent role in innate and adaptive immunity. Although histamine is normally associated with pathological conditions or allergic and anaphylactic reactions, it may contribute beneficially to the normal changes that occur within skeletal muscle during the recovery from exercise. We show that the human response to exercise includes an altered expression of thousands of protein-coding genes, and much of this response appears to be driven by histamine.

Effect of antioxidants on histamine receptor activation and sustained postexercise vasodilatation in humans.

What is the central question of this study? Is exercise-induced oxidative stress the upstream exercise-related signalling mechanism that leads to sustained postexercise vasodilatation via activation of H1 and H2 histamine receptors? What is the main finding and its importance? Systemic administration of the antioxidant ascorbate inhibits sustained postexercise vasodilatation to the same extent as seen previously with H1 and H2 histamine receptor blockade following small muscle-mass exercise. However, ascorbate has a unique ability to catalyse the degradation of histamine. We also found that systemic infusion of the antioxidant N-acetylcysteine had no effect on sustained postexercise vasodilatation, suggesting that exercise-induced oxidative stress does not contribute to sustained postexercise vasodilatation.

Neurovascular control following small muscle-mass exercise in humans.

Sustained postexercise vasodilation, which may be mediated at both a neural and vascular level, is seen in previously active skeletal muscle vascular beds following both large and small muscle-mass exercise. Blunted sympathetic vascular transduction and a downward resetting of the arterial baroreflex contribute to this vasodilation after cycling (large muscle-mass exercise), but it is unknown if these responses also contribute to sustained vasodilation following small muscle-mass exercise. This study aimed to determine if baroreflex sensitivity is altered, the baroreflex is reset, or if sympathetic vascular transduction is blunted following small muscle-mass exercise.

Blood pressure regulation X: what happens when the muscle pump is lost? Post-exercise hypotension and syncope.

Syncope which occurs suddenly in the setting of recovery from exercise, known as post-exercise syncope, represents a failure of integrative physiology during recovery from exercise. We estimate that between 50 and 80% of healthy individuals will develop pre-syncopal signs and symptoms if subjected to a 15-min head-up tilt following exercise. Post-exercise syncope is most often neurally mediated syncope during recovery from exercise, with a combination of factors associated with post-exercise hypotension and loss of the muscle pump contributing to the onset of the event.

A retrospective cohort study on the influence of UV index and race/ethnicity on risk of stress and lower limb fractures.

Background: Low vitamin D status increases the risk of stress fractures. As ultraviolet (UV) light is required for vitamin D synthesis, low UV light availability is thought to increase the risk of vitamin D insufficiency and poor bone health. The purpose of this investigation was to determine if individuals with low UV intensity at their home of record (HOR) or those with darker complexions are at increased risk of developing stress fractures and lower limb fractures during U.

The effect of heat acclimation on sweat microminerals: artifact of surface contamination.

Unlabelled: Heat acclimation (HA) reportedly conveys conservation in sweat micromineral concentrations when sampled from arm sweat, but time course is unknown. The observation that comprehensive cleaning of the skin surface negates sweat micromineral reductions during prolonged sweating raises the question of whether the reported HA effect is real or artifact of surface contamination.

Purpose: To measure sweat mineral concentrations serially during HA and determine if surface contamination plays a role in the reported mineral reductions.

Surface contamination artificially elevates initial sweat mineral concentrations.

Several sweat mineral element concentrations decline with serial sampling. Possible causes include reduced dermal mineral concentrations or flushing of surface contamination. The purpose of this study was to simultaneously sample mineral concentrations in transdermal fluid (TDF), sweat, and serum during extended exercise-heat stress to determine if these compartments show the same serial changes during repeat sampling.

Marginal effects of a large caffeine dose on heat balance during exercise-heat stress.

Unlabelled: The use of caffeine supplements in athletic and military populations has increased in recent years. Excessive caffeine consumption in conjunction with exercise in a hot environment may predispose individuals to heat illness.

Purpose: To examine heat balance induced by a large dose of caffeine during exercise in a hot environment.