Intermittent hypercapnic hypoxia during sleep does not induce ventilatory long-term facilitation in healthy males
Intermittent hypoxia-induced ventilatory neuroplasticity is likely important in obstructive sleep apnea pathophysiology. Although concomitant CO2 levels and arousal state critically influence neuroplastic effects of intermittent hypoxia, no studies have investigated intermittent hypercapnic hypoxia effects during sleep in humans. Thus the purpose of this study was to investigate if intermittent hypercapnic hypoxia during sleep induces neuroplasticity (ventilatory long-term facilitation and increased chemoreflex responsiveness) in humans. Twelve healthy males were exposed to intermittent hypercapnic hypoxia (24 x 30 s episo...
Source: Journal of Applied Physiology - September 6, 2017 Category: Physiology Authors: Deacon, N. L., McEvoy, R. D., Stadler, D. L., Catcheside, P. G. Tags: RESEARCH ARTICLE Source Type: research
Postnatal airway growth in cystic fibrosis piglets
Mutations in the gene encoding the cystic fibrosis (CF) transmembrane conductance regulator (CFTR) anion channel cause CF. The leading cause of death in the CF population is lung disease. Increasing evidence suggests that in utero airway development is CFTR-dependent and that developmental abnormalities may contribute to CF lung disease. However, relatively little is known about postnatal CF airway growth, largely because such studies are limited in humans. Therefore, we examined airway growth and lung volume in a porcine model of CF. We hypothesized that CF pigs would have abnormal postnatal airway growth. To test this hy...
Source: Journal of Applied Physiology - September 1, 2017 Category: Physiology Authors: Adam, R. J., Abou Alaiwa, M. H., Bouzek, D. C., Cook, D. P., Gansemer, N. D., Taft, P. J., Powers, L. S., Stroik, M. R., Hoegger, M. J., McMenimen, J. D., Hoffman, E. A., Zabner, J., Welsh, M. J., Meyerholz, D. K., Stoltz, D. A. Tags: RESEARCH ARTICLE Source Type: research
Ontogeny of myosin isoform expression and prehensile function in the tail of the gray short-tailed opossum (Monodelphis domestica)
This study uses an integrative approach of relating both MHC gene and protein expression with behavioral and morphometric changes to reveal a predominant fast MHC expression with subtle isoform transitions in caudal muscle across ontogeny. The functional shifts observed are most notably correlated with increased tail grasping for nesting activities. (Source: Journal of Applied Physiology)
Source: Journal of Applied Physiology - September 1, 2017 Category: Physiology Authors: Thomas, D. R., Chadwell, B. A., Walker, G. R., Budde, J. E., VandeBerg, J. L., Butcher, M. T. Tags: RESEARCH ARTICLE Source Type: research
Neuromuscular electrical stimulation improves skeletal muscle regeneration through satellite cell fusion with myofibers in healthy elderly subjects
The aim of this study was to determine whether neuromuscular electrical stimulation (NMES) affects skeletal muscle regeneration through a reduction of oxidative status in satellite cells of healthy elderly subjects. Satellite cells from the vastus lateralis skeletal muscle of 12 healthy elderly subjects before and after 8 wk of NMES were allowed to proliferate to provide myogenic populations of adult stem cells [myogenic precursor cells (MPCs)]. These MPCs were then investigated in terms of their proliferation, their basal cytoplasmic free Ca2+ concentrations, and their expression of myogenic regulatory factors (PAX3, PAX7...
Source: Journal of Applied Physiology - September 1, 2017 Category: Physiology Authors: Di Filippo, E. S., Mancinelli, R., Marrone, M., Doria, C., Verratti, V., Toniolo, L., Dantas, J. L., Fulle, S., Pietrangelo, T. Tags: RESEARCH ARTICLE Source Type: research
Reply to Coopers letter in reference to: Measurement of the maximum oxygen uptake VO2max: VO2peak is no longer acceptable
(Source: Journal of Applied Physiology)
Source: Journal of Applied Physiology - August 22, 2017 Category: Physiology Authors: Poole, D. C., Jones, A. M. Tags: LETTERS TO THE EDITOR Source Type: research
Rethinking VO2max: right problem, wrong solution (Letter to the Editor regarding Poole and Jones "Measurement of the maximum oxygen uptake VO2max: VO2peak is no longer acceptable")
(Source: Journal of Applied Physiology)
Source: Journal of Applied Physiology - August 22, 2017 Category: Physiology Authors: Cooper, D. M. Tags: LETTERS TO THE EDITOR Source Type: research
Reflex cardiorespiratory events from esophageal origin are heightened by preterm birth
In conclusion, esophageal stimulation induces inhibitory cardiorespiratory reflexes, which are partly mediated by C-fibers and more pronounced in preterm lambs. Clinical relevance of these findings requires further studies, especially in conditions associated with increased cardiorespiratory events, e.g., neonatal infection.
NEW & NOTEWORTHY Preterm birth heightens the cardiorespiratory events triggered by esophageal stimulation. The most extensive cardiorespiratory events are induced by simultaneous stimulation of the proximal and distal esophagus. (Source: Journal of Applied Physiology)
Source: Journal of Applied Physiology - August 22, 2017 Category: Physiology Authors: Nault, S., Samson, N., Nadeau, C., Djeddi, D., Praud, J.-P. Tags: RESEARCH ARTICLE Source Type: research
Skeletal muscle morphology, protein synthesis, and gene expression in Ehlers-Danlos syndrome
This study is the first of its kind to systematically investigate muscle biopsies from Ehlers-Danlos patients, focusing on muscle structure and function. These patients suffer from severe muscle symptoms, but in our study they show surprisingly normal muscle findings, which points toward indirect muscle symptoms originating from the surrounding connective tissue. These findings have basal physiological importance and implications for future physiotherapeutic treatment options for these patients. (Source: Journal of Applied Physiology)
Source: Journal of Applied Physiology - August 22, 2017 Category: Physiology Authors: Nygaard, R. H., Jensen, J. K., Voermans, N. C., Heinemeier, K. M., Schjerling, P., Holm, L., Agergaard, J., Mackey, A. L., Andersen, J. L., Remvig, L., Kjaer, M. Tags: RESEARCH ARTICLE Source Type: research
Application of Euclidean distance mapping for assessment of basement membrane thickness distribution in asthma
This report describes an automated, unbiased approach which uses color segmentation to identify structures of interest on stained sections and Euclidean distance mapping to measure the thickness distribution of airway structures. This method was applied to study the thickness distribution of the basement membrane and airway epithelium in lungs donated for research from seven nonasthmatic and eight asthmatic age- and sex-matched donors. A total of 60 airways were assessed. We report that the thickness and thickness distribution of the basement membrane and airway epithelium are increased in large and small airways of asthma...
Source: Journal of Applied Physiology - August 22, 2017 Category: Physiology Authors: Mostaco-Guidolin, L., Hajimohammadi, S., Vasilescu, D. M., Hackett, T.-L. Tags: INNOVATIVE METHODOLOGY Source Type: research
Exercise: Teaching myocytes new tricks
Endurance exercise training promotes numerous cellular adaptations in both cardiac myocytes and skeletal muscle fibers. For example, exercise training fosters changes in mitochondrial function due to increased mitochondrial protein expression and accelerated mitochondrial turnover. Additionally, endurance exercise training alters the abundance of numerous cytosolic and mitochondrial proteins in both cardiac and skeletal muscle myocytes, resulting in a protective phenotype in the active fibers; this exercise-induced protection of cardiac and skeletal muscle fibers is often referred to as "exercise preconditioning." As few a...
Source: Journal of Applied Physiology - August 22, 2017 Category: Physiology Authors: Powers, S. K. Tags: REVIEW Source Type: research
Postexercise cold water immersion modulates skeletal muscle PGC-1{alpha} mRNA expression in immersed and nonimmersed limbs: evidence of systemic regulation
We report for the first time that local cooling of the immersed limb evokes transcriptional control of PGC-1α in the nonimmersed limb, suggesting increased systemic β-adrenergic activation of AMPK may mediate, in part, postexercise cold induction of PGC-1α mRNA.
NEW & NOTEWORTHY We report for the first time that postexercise cold water immersion of one limb also enhances PGC-1α expression in a contralateral, nonimmersed limb. We suggest that increased systemic β-adrenergic stimulation, and not localized cooling per se, exerts regulatory effects on local signaling cascades, thereby modulating...
Source: Journal of Applied Physiology - August 22, 2017 Category: Physiology Authors: Allan, R., Sharples, A. P., Close, G. L., Drust, B., Shepherd, S. O., Dutton, J., Morton, J. P., Gregson, W. Tags: RESEARCH ARTICLE Source Type: research
Postmeal exercise blunts postprandial glucose excursions in people on metformin monotherapy
Metformin is used clinically to reduce fasting glucose with minimal effects on postprandial glucose. Postmeal exercise reduces postprandial glucose and may offer additional glucose-lowering benefit beyond that of metformin alone, yet controversy exists surrounding exercise and metformin interactions. It is currently unknown how postmeal exercise and metformin monotherapy in combination will affect postprandial glucose. Thus, we examined the independent and combined effects of postmeal exercise and metformin monotherapy on postprandial glucose. A randomized crossover design was used to assess the influence of postmeal exerc...
Source: Journal of Applied Physiology - August 22, 2017 Category: Physiology Authors: Erickson, M. L., Little, J. P., Gay, J. L., McCully, K. K., Jenkins, N. T. Tags: RESEARCH ARTICLE Source Type: research
Exercise training in heart failure: which training modality works best?
(Source: Journal of Applied Physiology)
Source: Journal of Applied Physiology - August 22, 2017 Category: Physiology Authors: Gielen, S. Tags: EDITORIAL FOCUS Source Type: research
Experimental intermittent ischemia augments exercise-induced inflammatory cytokine production
In conclusion, the present study demonstrates that ischemic, small-muscle endurance exercise elicits local inflammatory cytokine production compared with nonischemic exercise.
NEW & NOTEWORTHY We demonstrate that ischemic, small-muscle endurance exercise elicits local inflammatory cytokine production compared with nonischemic exercise. The present study advances our knowledge of the inflammatory response to exercise in a partial ischemic state, which may be relevant for understanding the therapeutic effects of exercise training for people with ischemic cardiovascular disease-associated comorbidities. (Source: Journal o...
Source: Journal of Applied Physiology - August 10, 2017 Category: Physiology Authors: Shill, D. D., Polley, K. R., Willingham, T. B., Call, J. A., Murrow, J. R., McCully, K. K., Jenkins, N. T. Tags: RESEARCH ARTICLE Source Type: research
Effect of calf-raise training on rapid force production and balance ability in elderly men
In conclusion, functional neuromuscular capacity can be enhanced by home-based calf-raise exercise in elderly men, which may protect against mobility loss with aging. (Source: Journal of Applied Physiology)
Source: Journal of Applied Physiology - August 10, 2017 Category: Physiology Authors: Ema, R., Ohki, S., Takayama, H., Kobayashi, Y., Akagi, R. Tags: RESEARCH ARTICLE Source Type: research
