Peak inspiratory pressure-generating capacity is preserved in the mdx mouse model of Duchenne muscular dystrophy in early disease, despite profound diaphragm muscle weakness and reduced electrical activation, revealing adequate compensation by extra-diaphragmatic muscles. Respiratory system compensation is lost as disease progresses, with the emergence of reduced peak inspiratory pressure-generating capacity in advanced disease. We hypothesised that extra-diaphragmatic inspiratory muscles compensate for diaphragm dysfunction in early dystrophic disease, supporting the maintenance of peak respiratory performance in mdx mice.
View Article and Find Full Text PDFDuchenne muscular dystrophy (DMD) is characterized by respiratory muscle injury and weakness, ultimately leading to respiratory failure. Impaired respiratory muscle performance, fibrosis and inflammation in early disease are evident in the dystrophin-deficient mdx mouse model of DMD. Prednisone or similar treatment is the current standard of care for DMD and exerts its benefits via an anti-inflammatory action, but chronic treatment is associated with side-effects.
View Article and Find Full Text PDFNeurovascular coupling (NVC) is the link between local neuronal activity and regional cerebral blood flow. High altitude (HA) ascent induces acute hypoxic vasodilation of the cerebral vasculature, with associated changes in CO and acid-base status. We aimed to characterise the effects of (a) acute removal of the HA-induced vasodilation and (b) rapid ascent to and residency at HA on NVC responses.
View Article and Find Full Text PDFDuchenne muscular dystrophy (DMD) is an X-linked devastating disease caused by a lack of dystrophin which results in progressive muscle weakness. As muscle weakness progresses, respiratory insufficiency and hypoventilation result in significant morbidity and mortality. The most studied DMD mouse model- the mdx mouse- has a milder respiratory phenotype compared to humans, likely due to compensatory overexpression of utrophin.
View Article and Find Full Text PDFThe present study was designed to test the potential utility of regional cerebral oxygen saturation (rcSO) in detecting term infants with brain injury. The study also examined whether quantitative rcSO features are associated with grade of hypoxic ischaemic encephalopathy (HIE). We analysed 58 term infants with HIE (>36 weeks of gestational age) enrolled in a prospective observational study.
View Article and Find Full Text PDFAntioxidants (Basel)
September 2024
Obstructive sleep apnoea (OSA) involves impaired upper airway muscle function and is linked to several pathologies including systemic hypertension, daytime somnolence and cognitive decline. Selenium is an essential micronutrient that exerts many of its effects through selenoproteins. Evidence indicates that either deficient or excessive dietary selenium intake can result in impaired muscle function, termed nutritional myopathy.
View Article and Find Full Text PDFDuchenne muscular dystrophy (DMD) is a fatal genetic neuromuscular disease. Lack of dystrophin in skeletal muscles leads to intrinsic weakness, injury, subsequent degeneration and fibrosis, decreasing contractile function. Dystropathology eventually presents in all inspiratory and expiratory muscles of breathing, severely curtailing their critical function.
View Article and Find Full Text PDFDuchenne muscular dystrophy (DMD) is a fatal genetic neuromuscular disorder, characterised by progressive decline in skeletal muscle function due to the secondary consequences of dystrophin deficiency. Weakness extends to the respiratory musculature, and cardiorespiratory failure is the leading cause of death in men with DMD. Intermittent hypoxia has emerged as a potential therapy to counteract ventilatory insufficiency by eliciting long-term facilitation of breathing.
View Article and Find Full Text PDFHigh altitude (HA) ascent imposes systemic hypoxia and associated risk of acute mountain sickness. Acute hypoxia elicits a hypoxic ventilatory response (HVR), which is augmented with chronic HA exposure (i.e.
View Article and Find Full Text PDFObjective: Reno-renal reflexes are disturbed in cardiovascular and hypertensive conditions when elevated levels of pro-inflammatory mediators/cytokines are present within the kidney. We hypothesised that exogenously administered inflammatory cytokines tumour necrosis factor alpha (TNF-α) and interleukin (IL)-1β modulate the renal sympatho-excitatory response to chemical stimulation of renal pelvic sensory nerves.
Methods: In anaesthetised rats, intrarenal pelvic infusions of vehicle [0.
Functional magnetic resonance imaging (fMRI) suggests that the hypoxic ventilatory response is facilitated by the AMP-activated protein kinase (AMPK), not at the carotid bodies, but within a subnucleus (Bregma -7.5 to -7.1 mm) of the nucleus tractus solitarius that exhibits right-sided bilateral asymmetry.
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