Objective: Contraction of upper airway (UA) muscles such as the geniohyoids and sternohyoids dilates and/or stabilizes the UA, thereby maintaining its patency. Obstructive sleep apnea (OSA) is caused by episodes of UA collapse, and this results in chronic episodic hypoxia. Chronic continuous hypoxia affects skeletal muscle structure and function, but the effects of chronic episodic hypoxia on UA muscle structure and function are unknown.
Design: Rats were exposed to alternating periods of hypoxia and normoxia twice per minute for 8 h/d for 5 weeks in order to mimic the intermittent hypoxia of OSA in humans. Isometric contractile properties were determined using strips of isolated geniohyoid and sternohyoid muscles in physiologic saline solution at 30 degrees C. Fiber-type distribution was determined using adenosine triphosphatase staining.
Results: Chronic episodic hypoxia had no significant effect on twitch or tetanic tension, twitch/tetanic tension ratio, contractile kinetics, tension-frequency relationship, or fiber-type distribution for either the sternohyoid or geniohyoid muscle. However, chronic episodic hypoxia did significantly increase sternohyoid and geniohyoid fatigue and reduced recovery from fatigue.
Conclusions: Chronic episodic hypoxia increases UA muscle fatigue, an effect that may compromise the maintenance of UA patency.
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http://dx.doi.org/10.1378/chest.122.3.1012 | DOI Listing |
Vet Clin North Am Equine Pract
January 2025
Michigan State University, Large Animal Clinical Sciences, College of Veterinary Medicine, East Lansing, MI, USA. Electronic address:
Horses are particularly susceptible to developing exertional rhabdomyolysis (ER) characterized by muscle stiffness, pain, and reluctance to move. Diagnosis requires establishing abnormal increases in serum creatine kinase activity when horses exhibit clinical signs. The 2 main categories of ER include sporadic ER arising from extrinsic causes and chronic ER that arises from intrinsic continuous or episodic abnormalities in muscle function.
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January 2025
Division of Vascular and Endovascular Surgery, Massachusetts General Hospital, Boston, MA. Electronic address:
Objectives: Chronic Kidney Disease (CKD) has been associated with a prothrombotic state. CKD affects hemostasis through altered platelet function and coagulation factors. Traditional tests provide limited insight into these changes.
View Article and Find Full Text PDFBehav Brain Res
January 2025
Department of Psychiatry, Renmin Hospital of Wuhan University, Wuhan 430060, Hubei, PR China; Department of Psychiatry and Institute of Neuropsychiatry, Renmin Hospital of Wuhan University, Wuhan 430060, Hubei, PR China; Taikang Center for Life and Medical Sciences, Wuhan University, Wuhan, 430071, China. Electronic address:
Background: The global burden of major depressive disorder (MDD) is rising, with current diagnostic methods hindered by significant subjectivity and low inter-rater reliability. Several studies have implied underlying link between coagulation-related proteins, such as kininogen (KNG) and coagulation factor VIII (FVIII), and depressive symptoms, offering new insights into the exploration of depression biomarkers. This study aims to elucidate the roles of KNG and FVIII in depression, potentially providing a foundational basis for biomarker research in this field.
View Article and Find Full Text PDFInfect Immun
January 2025
Department of Microbiology and Immunology, University of Western Ontario, London, Ontario, Canada.
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