Orthostatic intolerance follows actual weightlessness and weightlessness 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 simulated orthostasis [supine lower body negative pressure (LBNP)] immediately following LBNP exercise maintains orthostatic tolerance during bed rest. Identical twins (14 women, 16 men) underwent 30 days of 6 degrees head-down tilt bed rest. One of each pair was randomly selected as a control, and their sibling performed 40 min/day of treadmill exercise while supine in 53 mmHg (SD 4) [7.05 kPa (SD 0.50)] LBNP. LBNP continued for 5 min after exercise stopped. Head-up tilt at 60 degrees plus graded LBNP assessed orthostatic tolerance before and after bed rest. Hemodynamic measurements accompanied these tests. Bed rest decreased orthostatic tolerance time to a greater extent in control [34% (SD 10)] than in countermeasure subjects [13% (SD 20); P < 0.004]. Controls exhibited cardiac stroke volume reduction and relative cardioacceleration typically seen after bed rest, yet no such changes occurred in the countermeasure group. These findings demonstrate that 40 min/day of supine LBNP treadmill exercise followed immediately by 5 min of resting LBNP attenuates, but does not fully prevent, the orthostatic intolerance associated with 30 days of bed rest. We speculate that longer postexercise LBNP may improve results. Together with our earlier related studies, these ground-based results support spaceflight evaluation of postexercise orthostatic stress as a time-efficient countermeasure against postflight orthostatic intolerance.
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http://dx.doi.org/10.1152/japplphysiol.00132.2007 | DOI Listing |
Med Devices (Auckl)
December 2024
Department of Biomedical, Metabolic and Neural Sciences, University of Modena and Reggio Emilia, Modena, Italy.
Background: The number of cardiac implantable electronic devices (CIEDs) implanted has been growing and the population who receive the device is older and has more comorbidities. Long bed rest and immobilisation have always been common after the implant, but a consensus does not exist on the argument.
Purpose: To map and synthesise available literature on the mobilisation approach after the implant of a CIED and which correlated outcomes exist.
Aerosp Med Hum Perform
December 2024
Introduction: Facial expression perception is the process by which someone can interpret the emotion of another individual using their facial cues. Below-average scores on tests designed to measure facial expression recognition (FER) accuracies are associated with inappropriate behavioral responses and are often linked to mental or neurological disorders. Head-down bed rest microgravity analog studies show changes in facial emotion processing that may indicate a behavioral health risk during spaceflight.
View Article and Find Full Text PDFJ Physiol Anthropol
December 2024
Department of Sports and Life Sciences, National Institute of Fitness and Sports in Kanoya, 1 Shiromizu, Kanoya, Kagoshima, 891-2393, Japan.
Background: Circulating fatty acid-binding protein 4 (FABP4) influences cardiovascular disease and glucose metabolism. Acute aerobic exercise increases circulating FABP4 concentrations, but the factors underlying this effect in humans are unclear. We investigated the effect of exercise duration on circulating FABP4 concentrations in healthy men.
View Article and Find Full Text PDFJ Cardiothorac Surg
December 2024
Department of Cardiothoracic Surgery, Suining Central Hospital, No. 127, Desheng Road, Chuanshan District, Suining, 629000, China.
Background: The conventional arteriovenous approach closure of patent ductus arteriosus (PDA) may be associated with more complications, especially in young infants. The objective is to explore the feasibility and clinical efficacy of interventional closure of PDA through a single venous approach under echocardiography without angiography.
Methods: 112 patients (32 males and 80 females) with PDA closed by different methods in Suining Central Hospital were enrolled, including 60 cases (Group 1) with a single venous approach under echocardiography without angiography and 52 cases (Group 2) with the conventional arteriovenous approach.
Pediatr Int
December 2024
Department of Pediatrics, Kurume University School of Medicine, Kurume, Fukuoka, Japan.
Background: Transradial access (TRA) is not a common vascular access in children. We have been performing TRA actively to reduce puncture complications, and the purpose of this study was to investigate the safety and efficacy of TRA in young children.
Methods: The study included 29 patients aged 5-12 years who underwent diagnostic catheterization at Kurume University Hospital.
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