Effects of short vs. prolonged mechanical ventilation on antioxidant systems in piglet diaphragm.

Objective: Prolonged controlled mechanical ventilation (MV) is known to induce diaphragmatic oxidative stress that seems to be an important factor reducing force-generating capacity. To better understand the cellular mechanisms involved, this work examined the effect of short vs. prolonged MV on antioxidant defense in the diaphragm.

Changes in respiratory muscle endurance during puberty.

The evaluation of respiratory muscle endurance provides clinically useful information on muscle function, especially in children with respiratory and neuromuscular diseases. However, endurance may be lower in young children than in older children because of the major physical changes of puberty. We thus compared respiratory muscle endurance in 15 healthy pre- and peripubertal children (S1-S2/P1 group) and 14 healthy children near the end of the pubertal process (S4P4 group).

The effect of respiratory muscle training with CO2 breathing on cellular adaptation of mdx mouse diaphragm.

The aim of our study was to investigate the cellular mechanisms induced by hypercapnic stimulation of ventilation, during 6 weeks/30 min per day, in 10 mdx and 8 C57BL10 mice (10+/-0.2 months old). Ten mdx and eight C57BL10 mice served as control group.

Effect of age on Hsp72 expression in leukocytes of healthy active people.

Aging mammalians show reduced expression and induction of cytoprotective heat shock proteins in response to physiological stresses. Physical training can increase Hsp72 expression in young and old animals, but whether same adaptations can be observed in old people remains unknown. We hypothesized that the maintenance of physical activity during aging should preserve Hsp72 expression in leukocytes of elderly people.

Does oxidative stress alter quadriceps endurance in chronic obstructive pulmonary disease?

The role of exercise-induced oxidative stress in the reduced quadriceps endurance of chronic obstructive pulmonary disease (COPD) patients has never been shown. We conducted a randomized, double-blind, and crossover study in which nine severe patients performed localized dynamic quadriceps endurance tests at 40% of maximal strength after oral treatment with the antioxidant, N-acetylcysteine (NAC), and placebo. Venous blood was sampled before, immediately after exercise, and 6 hours later.

Exercise-induced quadriceps oxidative stress and peripheral muscle dysfunction in patients with chronic obstructive pulmonary disease.

Exercise-induced muscle oxidative stress may be involved in the myopathy associated with chronic obstructive pulmonary disease (COPD). This study was designed to look at whether local exercise induces muscle oxidative stress and whether this oxidative stress may be associated with the reduced muscle endurance in patients with COPD. Quadriceps endurance was measured in 12 patients with COPD (FEV1 = 0.