Background: Acute rhinosinusitis is a common problem that could occur in space secondary to absence of gravity-dependent drainage or odontogenic or external sources of infection. The purpose of this study was to determine the efficacy of ultrasound to determine sinus fluid distribution levels in swine and to assess the accuracy of ultrasound in the animal during normal and microgravity conditions.
Methods: Anesthetized swine had a catheter placed through a frontal bone window to allow aliquots of a viscous solution to be injected at 1 G (N = 4) or during brief microgravity parabolic flights (N = 4). Ultrasound examinations were performed with a high frequency probe during baseline and fluid-induced conditions.
Results: There was a consistent air-fluid level interface seen on ultrasound examination with the injection of 1 ml of fluid during 1-G conditions. Microgravity conditions caused the rapid (< 10 s) dissolution of the air-fluid level associated with dispersion of the fluid to the walIs of the sinus cavity in a uniform fashion. The air-fluid interface was recreated with return to 1 G.
Conclusions: Ultrasound is a reliable diagnostic test for assessing fluid levels; these experiments demonstrate the technique can be used during microgravity conditions with attention to altered fluid behavior in the absence of gravity.
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http://dx.doi.org/10.3357/asem.2381.2009 | DOI Listing |
Aerosp Med Hum Perform
January 2025
Introduction: In space, under weightlessness conditions, human brain activity is changed due to the shifting of body fluid and blood toward the cephalic region. This shifting leads to changes in cerebral hemodynamics and, consequently, neurophysiological function, which impacts mental functions like cognition and decision-making capabilities of space travelers. The present study reports the effect of acute exposure to simulated microgravity on cognitive functions and event-related potentials.
View Article and Find Full Text PDFDokl Biochem Biophys
January 2025
Institute of Biomedical Problems, Russian Academy of Sciences, 123007, Moscow, Russia.
One of the most obvious manifestations of the negative impact of space flight factors on the human physiology is osteopenia. With the active development of manned space flights and the increase in the duration of humans' persistence in weightlessness, there is a growing need to understand the mechanisms of changes occurring at the cellular level involved in the replenishment of bone tissue. Using the RNA sequencing method, changes in the transcriptome profile of MMSCs were studied after a 5-day simulation of the microgravity effects.
View Article and Find Full Text PDFFront Psychol
January 2025
Institute for Kinesiology Research, Science and Research Centre Koper, Koper, Slovenia.
Bed rest (BR) studies are primarily designed to investigate the effects of weightlessness on the human body, but they are also used to study the effects of physical inactivity. For this purpose, participants are typically recruited from the general population without requiring specialized training, which contrasts with the selection process for cosmonauts. The BR study environment is often characterized as highly stressful, highlighting the importance of understanding coping mechanisms and adaptation strategies among participants, as well as the role of their daily interactions.
View Article and Find Full Text PDFJ Orthop Surg Res
January 2025
Department of Orthopedic Surgery, Beijing Chaoyang Hospital, Capital Medical University of China, Gongti South Rd, No. 8, Beijing, 100020, China.
Objective: This study aims to investigate changes in matrix metalloproteinase (MMP) and tissue inhibitor of metalloproteinase (TIMP) levels in the intervertebral discs of New Zealand white rabbits under simulated overload and microgravity conditions, focusing on the expression of MMP1, MMP3, and TIMP1. The findings aim to provide a theoretical foundation for preventing and delaying lumbar disc degeneration in these environments.
Methods: Overload was simulated using an animal centrifuge, and microgravity was mimicked through tail suspension.
Cell Mol Life Sci
January 2025
Department of Aerospace Medical Training, School of Aerospace Medicine, Fourth Military Medical University, 169 Chang Le Xi Road, Xi'an, 710032, China.
Background: Prolonged spaceflight is known to cause vascular deconditioning and remodeling. Tail suspension, a widely used spaceflight analog, is reported to result in vascular remodeling of rats. However, little is known about the cellular atlas of the heterogeneous cells of CA and FA from hindlimb-unloaded rats.
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