Acute volume loading exacerbates direct ventricular interaction in a model of COPD
Volume loading increases left ventricular (LV) stroke volume (LVSV) through series interaction, but may paradoxically reduce LVSV in the presence of large increases in right ventricular (RV) afterload because of direct ventricular interaction (DVI). RV afterload is often increased in chronic obstructive pulmonary disease (COPD) as a result of pathological changes to respiratory mechanics, namely increased negative intrathoracic pressure (nITP), dynamic lung hyperinflation (DH), and increased pulmonary vascular resistance (PVR). These hallmarks of COPD negatively impact LV hemodynamics in normovolemia. However, it is unknow...
Source: Journal of Applied Physiology - November 6, 2017 Category: Physiology Authors: Cheyne, W. S., Williams, A. M., Harper, M. I., Eves, N. D. Tags: RESEARCH ARTICLE Source Type: research
Imaging IGF-I uptake in growth plate cartilage using in vivo multiphoton microscopy
Bones elongate through endochondral ossification in cartilaginous growth plates located at ends of primary long bones. Linear growth ensues from a cascade of biochemical signals initiated by actions of systemic and local regulators on growth plate chondrocytes. Although cellular processes are well defined, there is a fundamental gap in understanding how growth regulators are physically transported from surrounding blood vessels into and through dense, avascular cartilage matrix. Intravital imaging using in vivo multiphoton microscopy is one promising strategy to overcome this barrier by quantitatively tracking molecular de...
Source: Journal of Applied Physiology - November 6, 2017 Category: Physiology Authors: Serrat, M. A., Ion, G. Tags: INNOVATIVE METHODOLOGY Source Type: research
Effects of {beta}-hydroxy-{beta}-methylbutyrate on skeletal muscle mitochondrial content and dynamics, and lipids after 10 days of bed rest in older adults
Loss of muscle mass during periods of disuse likely has negative health consequences for older adults. We have previously shown that β-hydroxy-β-methylbutyrate (HMB) supplementation during 10 days of strict bed rest (BR) attenuates the loss of lean mass in older adults. To elucidate potential molecular mechanisms of HMB effects on muscle during BR and resistance training rehabilitation (RT), we examined mediators of skeletal muscle mitochondrial dynamics, autophagy and atrophy, and intramyocellular lipids. Nineteen older adults (60–76 yr) completed 10 days BR followed by 8-wk RT rehabilitation. Subjects wer...
Source: Journal of Applied Physiology - November 6, 2017 Category: Physiology Authors: Standley, R. A., Distefano, G., Pereira, S. L., Tian, M., Kelly, O. J., Coen, P. M., Deutz, N. E. P., Wolfe, R. R., Goodpaster, B. H. Tags: RESEARCH ARTICLE Source Type: research
Green tea epigallocatechin gallate enhances cardiac function restoration through survival signaling expression in diabetes mellitus rats with autologous adipose tissue-derived stem cells
The present study tests a hypothesis that cardioprotective effects mediated by autologous adipose-derived stem cells (ADSC) in rats afflicted with insulin-dependent diabetes mellitus (IDDM) may be synergistically enhanced by oral treatment with green tea epigallocatechin gallate (EGCG). Wistar rats were divided into sham, DM, DM+ADSC (autologous transplanted 1 x 106 cells per rat), and DM+ADSC+E (E, green tea oral administration EGCG). Heart tissues were isolated from all rats, and investigations were performed after 2-mo treatment. In the sham, DM, and DM+ADSC groups, we found that DM induced cardiac dysfunction (sham and...
Source: Journal of Applied Physiology - November 2, 2017 Category: Physiology Authors: Chen, T.-S., Liou, S.-Y., Kuo, C.-H., Pan, L.-F., Yeh, Y.-L., Liou, J., Padma, V. V., Yao, C.-H., Kuo, W.-W., Huang, C.-Y. Tags: RESEARCH ARTICLE Source Type: research
Extra- and intracranial blood flow regulation during the cold pressor test: influence of age
We determined how the extra- and intracranial circulations respond to generalized sympathetic activation evoked by a cold pressor test (CPT) and whether this is affected by healthy aging. Ten young [23 ± 2 yr (means ± SD)] and nine older (66 ± 3 yr) individuals performed a 3-min CPT by immersing the left foot into 0.8 ± 0.3°C water. Common carotid artery (CCA) and internal carotid artery (ICA) diameter, velocity, and flow were simultaneously measured (duplex ultrasound) along with middle cerebral artery and posterior cerebral artery mean blood velocity (MCAvmean and PCAvmean) and cardiorespi...
Source: Journal of Applied Physiology - November 2, 2017 Category: Physiology Authors: Flück, D., Ainslie, P. N., Bain, A. R., Wildfong, K. W., Morris, L. E., Fisher, J. P. Tags: RESEARCH ARTICLE Source Type: research
Functional assessment of the diaphragm by speckle tracking ultrasound during inspiratory loading
This study evaluates the validity of speckle tracking ultrasound to quantify diaphragm contractility. Thirteen healthy volunteers underwent a randomized stepwise threshold loading protocol of 0–50% of the maximal inspiratory pressure. Electric activity of the diaphragm and transdiaphragmatic pressures were recorded. Speckle tracking ultrasound was used to assess strain and strain rate as measures of diaphragm tissue deformation and deformation velocity, respectively. Fractional thickening was assessed by measurement of diaphragm thickness at end-inspiration and end-expiration. Strain and strain rate increased with pr...
Source: Journal of Applied Physiology - November 2, 2017 Category: Physiology Authors: Oppersma, E., Hatam, N., Doorduin, J., van der Hoeven, J. G., Marx, G., Goetzenich, A., Fritsch, S., Heunks, L. M. A., Bruells, C. S. Tags: RESEARCH ARTICLE Source Type: research
An assessment of the autonomic nervous system in the electrohypersensitive population: a heart rate variability and skin conductance study
In conclusion, the HRV and SC profiles did not significantly differ between the EHS and control populations under no exposure. Exposure did not have an effect on the ANS parameters we have explored.
NEW & NOTEWORTHY This study provided analysis on the skin conductance parameters using a newly developed method (peak/min, extraction of skin conductance responses) that had not been performed previously. Additionally, the skin conductance signal was decomposed, considering tonic and phasic activities to be a distinct compound. Moreover, this is the first time a study has been designed into two steps to understand whether t...
Source: Journal of Applied Physiology - November 2, 2017 Category: Physiology Authors: Andrianome, S., Gobert, J., Hugueville, L., Stephan-Blanchard, E., Telliez, F., Selmaoui, B. Tags: RESEARCH ARTICLE Source Type: research
Frequency and magnitude of intermittent hypoxia modulate endothelial wound healing in a cell culture model of sleep apnea
In conclusion, the frequency and magnitude of hypoxia cycling in IH markedly alter wound healing responses and emerge as key factors determining how cells will respond in OSA.
NEW & NOTEWORTHY Intermittent hypoxia (IH) induces cardiovascular consequences in obstructive sleep apnea (OSA) patients. However, the vast array of frequencies and severities of IH previously employed in OSA-related experimental studies has led to controversial results on the effects of IH. By employing an optimized IH experimental system here, we provide evidence that the frequency and magnitude of IH markedly alter human aortic endothelial wou...
Source: Journal of Applied Physiology - November 1, 2017 Category: Physiology Authors: Campillo, N., Falcones, B., Montserrat, J. M., Gozal, D., Obeso, A., Gallego-Martin, T., Navajas, D., Almendros, I., Farre, R. Tags: RESEARCH ARTICLE Source Type: research
CORP: Measurement of lung function in small animals
The measurement of lung function in mice and rats is crucial for understanding how well small animal models of pulmonary disease recapitulate human clinical pathology but brings with it the challenge of making accurate measurements in animals as small as a mouse. Overcoming these challenges can be achieved in a number of ways, each based on a model idealization of how the lung works as a mechanical system. Accordingly, it is important to understand the theoretical basis on which an assessment of lung function rests to interpret experimental measurements appropriately. It is also crucial to attend to a number of practical i...
Source: Journal of Applied Physiology - November 1, 2017 Category: Physiology Authors: Bates, J. H. T. Tags: REVIEW Source Type: research
Edward F. Adolph Distinguished Lecture: Skin-deep insights into vascular aging
The skin is an accessible model circulation for studying vascular function and dysfunction across the lifespan. Age-related changes, as well as those associated with disease progression, often appear first in the cutaneous circulation. Furthermore, impaired vascular signaling and attendant endothelial dysfunction, the earliest indicators of cardiovascular pathogenesis, occur in a similar fashion across multiple tissue beds throughout the body, including the skin. Because microvascular dysfunction is a better predictor of long-term outcomes and adverse cardiovascular events than is large vessel disease, an understanding of ...
Source: Journal of Applied Physiology - November 1, 2017 Category: Physiology Authors: Kenney, W. L. Tags: REVIEW Source Type: research
The double-edged sword of intermittent hypoxia--can intermittent hypoxia be both deleterious and protective in OSA? Focus on "Frequency and magnitude of intermittent hypoxia modulate endothelial wound healing in a cell culture model of sleep apnea"
(Source: Journal of Applied Physiology)
Source: Journal of Applied Physiology - November 1, 2017 Category: Physiology Authors: Lavie, L., Lavie, P. Tags: EDITORIAL FOCUS Source Type: research
Reply to Francescato et al.: Interpreting the averaging methods to estimate oxygen uptake kinetics parameters
(Source: Journal of Applied Physiology)
Source: Journal of Applied Physiology - October 26, 2017 Category: Physiology Authors: Benson, A. P., Bowen, T. S., Ferguson, C., Murgatroyd, S. R., Rossiter, H. B. Tags: LETTERS TO THE EDITOR Source Type: research
Interpreting the averaging methods to estimate oxygen uptake kinetics parameters
(Source: Journal of Applied Physiology)
Source: Journal of Applied Physiology - October 26, 2017 Category: Physiology Authors: Francescato, M. P., Cettolo, V., Bellio, R. Tags: LETTERS TO THE EDITOR Source Type: research
Measurement of VO2max in clinical groups is feasible and necessary
(Source: Journal of Applied Physiology)
Source: Journal of Applied Physiology - October 26, 2017 Category: Physiology Authors: Williams, C. A., Saynor, Z. L., Barker, A. R., Oades, P. J., Tomlinson, O. W. Tags: LETTERS TO THE EDITOR Source Type: research
Last Word on Viewpoint: Loopomics: a new functional approach to life
(Source: Journal of Applied Physiology)
Source: Journal of Applied Physiology - October 26, 2017 Category: Physiology Authors: Burlando, B. Tags: VIEWPOINT Source Type: research
