Increased adiposity is associated with dysregulation of the endothelin system, both of which increase the risk of cardiovascular disease (CVD). Preclinical data indicate that endothelin dysregulation also reduces resting energy expenditure (REE). The objective was to test the hypothesis that endothelin receptor antagonism will increase REE in people with obesity compared with healthy weight individuals.
View Article and Find Full Text PDFSmoking increases systemic inflammation and circulating endothelin-1 (ET-1), both of which contribute to an elevated risk of cardiovascular disease (CVD). The present study sought to test the hypothesis that a 12-week smoking cessation intervention would contribute to a long-term reduction in circulating ET-1, tumor necrosis factor-alpha (TNF-α), and interleukin-6 (IL-6). 30 individuals participated in a 12-week evidence-based smoking cessation program at Augusta University.
View Article and Find Full Text PDFObesity is associated with dysregulation of the endothelin system. In individuals with obesity, an exaggerated pressor response to acute stress is accompanied by increased circulating endothelin-1 (ET-1). The impact of combined endothelin A/B receptor (ET) antagonism on the stress-induced pressor response in overweight/obese (OB) individuals is unknown.
View Article and Find Full Text PDFPrevious work on the comprehension of agreement has shown that incorrectly inflected verbs do not trigger responses typically seen with fully ungrammatical verbs when the preceding sentential context furnishes a possibly matching distractor noun (i.e., agreement attraction).
View Article and Find Full Text PDFIntroduction: There is ample evidence that overnight sleep and daytime naps benefit memory retention, compared to comparable amounts of active wakefulness. Yet recent evidence also suggests that a period of post-training rest (eg, quiet wakefulness with eyes closed) provides a similar memory benefit compared to wake. However, the relative benefits of sleep vs quiet waking rest on memory remain poorly understood.
View Article and Find Full Text PDFAcross a broad spectrum of memory tasks, retention is superior following a night of sleep compared to a day of wake. However, this result alone does not clarify whether sleep merely slows the forgetting that would otherwise occur as a result of information processing during wakefulness, or whether sleep actually consolidates memories, protecting them from subsequent retroactive interference. Two influential studies suggested that sleep protects memories against the subsequent retroactive interference that occurs when participants learn new yet overlapping information (interference learning).
View Article and Find Full Text PDFWhile several recent studies have found that a post-encoding period of quiet, eyes-closed waking rest benefits memory consolidation, others have reported null effects. To more precisely estimate this effect, we conducted a quasi-exact behavioural replication of a recent study from our lab, which found that post-training eyes-closed waking rest improved declarative memory relative to a distractor task. Contrary to our hypothesis, the observed effect was not significant; however, it did fall within the 95% confidence interval of our previous finding.
View Article and Find Full Text PDFUnlabelled: Traditional aerobic exercise reduces the risk of developing chronic diseases by inducing immune, metabolic, and myokine responses. Following traditional exercise, both the magnitude and time-course of these beneficial responses are different between obese compared to normal weight individuals. Although obesity may affect the ability to engage in traditional exercise, whole body vibration (WBV) has emerged as a more tolerable form of exercise .
View Article and Find Full Text PDFAchieving and maintaining an optimal level of hydration has significant implications for both acute and chronic health, yet many hydration assessments are not feasible for the general public. Urinary frequency (UF) is a reliable method to self-assess hydration status in healthy individuals, and thirst can provide additional sensory information on adequacy of daily fluid intake volume (DFI). However, threshold values for these indices to detect optimal hydration have not been determined.
View Article and Find Full Text PDFOxid Med Cell Longev
February 2020
Oxidative stress and vascular endothelial dysfunction are established characteristics of cystic fibrosis (CF). Oxidative stress may contribute to vascular dysfunction via inhibition of nitric oxide (NO) bioavailability. .
View Article and Find Full Text PDFBackground: New treatments have improved life-expectancy in patients with cystic fibrosis (CF); however, cardiovascular health remains an area of concern in this population. Flow-mediated dilation (FMD), a non-invasive assessment of vascular endothelial function that predicts future cardiovascular disease and events, is attenuated in patients with CF compared to controls. The reproducibility of FMD in CF; however, has yet to be evaluated.
View Article and Find Full Text PDFCystic fibrosis (CF) is a genetic disorder associated with vascular endothelial dysfunction. Nitric oxide (NO) plays a major role in maintaining vascular function, and tetrahydrobiopterin (BH) is a critical determinant of NO bioavailability. Thus the purpose of this study was to investigate the effects of oral administration of BH on endothelial function in patients with CF.
View Article and Find Full Text PDFIn the current study, we tested the effects of core body temperature increases (e.g. heat stress) on affect, self-reported physical discomfort, and subsequent self-control in male smokers and nonsmokers using a novel passive heat stress paradigm, within a distress tolerance framework.
View Article and Find Full Text PDFBackground: Ventilatory parameters obtained during exercise predict survival in several chronic diseases; however, long-term changes in exercise ventilatory parameters in patients with cystic fibrosis (CF) have yet to be examined and potential differences between sexes in CF are unknown.
Purpose: We sought to examine the change in exercise ventilatory parameters over time in patients with CF and determine if the change is different between sexes.
Methods: Exercise capacity (VO peak) and exercise ventilatory parameters (V/VO peak, V/VCO peak, and V/VCO slope) were determined from a maximal cardio-pulmonary test on a cycle ergometer on two visits separated by 39 ± 16 months in 20 patients with CF (10 female, 10 male).
It has been proposed that normal waking levels of acetylcholine (ACH) are important for initial memory acquisition, and that decreased ACH is critical for memory consolidation. Sleep is thought to benefit memory consolidation in part due to the predominance of low ACH levels observed during non-rapid eye movement sleep. Here we examined whether sleep and ACH suppression with the cholinergic antagonist scopolamine impact declarative and motor memory consolidation across a night of sleep or a day of wakefulness.
View Article and Find Full Text PDFAm J Physiol Heart Circ Physiol
November 2018
Cystic fibrosis (CF), characterized by defective CFTR function, is associated with multiple systemic complications, including vascular dysfunction. Sildenafil, a phosphodiesterase type 5 inhibitor, not only enhances nitric oxide (NO) metabolism but has been shown to improve CFTR functionality as well. Thus, sildenafil has been proposed as a therapy to improve vascular health in CF; however, its potential therapeutic role has yet to be determined.
View Article and Find Full Text PDFBackground: The independent effects of hypohydration and hyperthermia on cognition and mood is unclear since the two stresses often confound each other. Further, it is unknown if obese individuals have the same impairments during hyperthermia and hypohydration that is often observed in non-obese individuals.
Methods: The current study was designed to assess the independent and combined effects of mild hypohydration and hyperthermia on cognition, mood, and mental task load in obese and non-obese females.
This study aimed to examine the sleep-dependent memory consolidation of verbal declarative memory in Chinese adolescents in a naturalistic experimental setting. Thirty-nine healthy boarding school students (ages 15-18, 70% female) were randomized to either a one-hour afternoon nap or wake group between the baseline and the retest sessions of three verbal declarative memory tasks: a Prose Stories Recall task, a Word Pair Associates task, and Rey Auditory Verbal Learning Test. Results showed that the nap group performed better than the no-nap group on both the Prose Stories Recall task and the Word Pair Associates task, but not on list learning.
View Article and Find Full Text PDFIntroduction: Obesity and hypohydration independently affect postsynaptic endothelial function, but it is unknown if hypohydration affects lean and obese individuals differently.
Purpose: To examine the effect of hypohydration on postsynaptic cutaneous vasodilation and sweating in men with high and low adiposity (HI- and LO-BF, respectively).
Methods: Ten males with LO-BF and ten with HI-BF were instrumented for forearm microdialysis when euhydrated and hypohydrated.
We tested the hypothesis that oral NaHCO intake stimulates splenic anti-inflammatory pathways. Following oral NaHCO loading, macrophage polarization was shifted from predominantly M1 (inflammatory) to M2 (regulatory) phenotypes, and FOXP3CD4 T-lymphocytes increased in the spleen, blood, and kidneys of rats. Similar anti-inflammatory changes in macrophage polarization were observed in the blood of human subjects following NaHCO ingestion.
View Article and Find Full Text PDFBackground: Urine specific gravity (U) is often used to assess hydration status, particularly around athletic competition, but it is unknown whether high U is indicative of plasma volume (PV) reduction (i.e., hypohydration).
View Article and Find Full Text PDFBackground: The impact of blood flow regulation and oxidative stress during exercise in cystic fibrosis (CF) has yet to be investigated.
Methods: A maximal graded exercise test was conducted to determine exercise capacity (VO peak) and peak workload in 14 pediatric patients with mild CF (age 14±3y, FEV 93±16 % predicted) and 14 demographically-matched controls. On a separate visit, participants performed submaximal cycling up to 60% of peak workload where brachial artery blood velocity was determined using Doppler ultrasound.
Background: Responses to a single bout of exercise may provide critical information for maximizing improvements in pulmonary function following exercise training in cystic fibrosis (CF). We sought to determine if acute maximal exercise improves pulmonary function in patients with CF.
Methods: Thirty-three patients with CF completed a comprehensive assessment of pulmonary function to determine forced vital capacity (FVC), forced expiratory volume in one second (FEV), and lung clearance index (LCI) prior to and immediately following maximal aerobic exercise on a cycle ergometer.
Purpose: Prior evidence indicates that acute heat stress and aerobic exercise independently reduce arterial stiffness. The combined effects of exercise and heat stress on PWV are unknown. The purpose of this study was to determine the effects of heat stress with passive heating and exercise in the heat on arterial stiffness.
View Article and Find Full Text PDFContext: Exercising in the heat leads to an increase in body temperature that can increase the risk of heat illness or cause detriments in exercise performance.
Objective: To examine a phase change heat emergency kit (HEK) on thermoregulatory and perceptual responses and subsequent exercise performance following exercise in the heat.
Design: Two randomized crossover trials that consisted of 30 minutes of exercise, 15 minutes of treatment (T), performance testing (5-10-5 pro-agility test and 1500-m run), and another 15 minutes of treatment (T) identical to T.