Recent work indicates that infections are a major contributor to diaphragm weakness in patients who are critically ill and mechanically ventilated, and that diaphragm weakness is a risk factor for death and prolonged mechanical ventilation. Infections activate muscle calpain, but many believe this is an epiphenomenon and that other proteolytic processes are responsible for infection-induced mus...

The aim of this work was to quantify the ability to predict intrafraction diaphragm motion from an external respiration signal during a course of radiotherapy. The data obtained included diaphragm motion traces from 63 fluoroscopic lung procedures for 5 patients, acquired simultaneously with respiratory motion signals (an infrared camera-based system was used to track abdominal wall motion). Du...

Controlled mechanical ventilation (CMV) is known to result in rapid and severe diaphragmatic dysfunction, but the recovery response of the diaphragm to normal function after CMV is unknown. Therefore, we examined the time course of diaphragm function recovery in an animal model of CMV. Healthy rats were submitted to CMV for 24-27 h (n = 16), or to 24-h CMV followed by either 1 h (CMV + 1 h SB, ...

Structural adaptations that occur in the diaphragm muscle of patients with chronic obstructive pulmonary disease (COPD), namely an increase in type I fibers and a decrease in type II fibers, have been explored in terms of the active contractile properties of the diaphragm. The aim of this study was to test the passive properties of the diaphragm by measuring the force response of relaxed diaphr...

When the lung is inflated acutely, the capacity of the diaphragm to generate pressure, in particular pleural pressure (Ppl), is impaired because the muscle during contraction is shorter and generates less force. At very high lung volumes, the pressure-generating capacity of the diaphragm may be further reduced by an increase in the muscle radius of curvature. Lung inflation similarly impairs th...

BACKGROUND The optimal chemotherapy route for non-small cell lung cancers involving the phrenic nerve and diaphragm is unclear. The pharmacokinetic properties of paclitaxel following intravenous (IV) or intrapleural (IP) administration were analyzed in the plasma, lung, and diaphragm in a rat model. The purpose of this study was to determine whether IP injection increased paclitaxel concentrati...

Controlled mechanical ventilation (MV) is a life-saving measure for patients in respiratory failure. However, MV renders the diaphragm inactive leading to diaphragm weakness due to both atrophy and contractile dysfunction. It is now established that oxidative stress is a requirement for MV-induced diaphragmatic proteolysis, atrophy, and contractile dysfunction to occur. Given that endurance exe...

BACKGROUND The diaphragm is resistant to competitive neuromuscular blocking agents. Because of the competitive mechanism of action of tubocurarine, the rate of hydrolysis of acetylcholine at the neuromuscular junction may modulate its neuromuscular blocking effect. The authors compared the neuromuscular blocking effect of tubocurarine on isolated diaphragm and extensor digitorum longus (EDL) mu...

We investigated whether atrophy and hypertrophy signalling were altered in the diaphragm of chronic obstructive pulmonary disease (COPD) patients. We studied diaphragm fibre dimensions and proportion, expression of markers of the ubiquitin-proteasome pathway, nuclear factor (NF)-kappaB pathways, muscle regulatory factors and myostatin in diaphragm biopsies from 19 patients with severe COPD and ...

Controlled mechanical ventilation (CMV) is associated with the development of diaphragm atrophy and contractile dysfunction, and respiratory muscle weakness is thought to contribute significantly to delayed weaning of patients. Therefore, therapeutic strategies for preventing these processes may have clinical benefit. The aim of the current study was to investigate the role of the Janus kinase ...