PubMed Health⌕ Search

Biomedical subjects

Harry R Gosker

Publications and source records attributed to Harry R Gosker.

4 recordsLinked to original sources
PubMed2005

Altered antioxidant status in peripheral skeletal muscle of patients with COPD.

Despite the growing field of interest in the role of pulmonary oxidative stress in chronic obstructive pulmonary disease (COPD), barely any data are available with respect to antioxidant capacity in the peripheral musculature of these patients. The main objective of this study was to assess in detail the antioxidant status in skeletal muscle of patients with COPD. Biopsies from the vastus lateralis of 21 patients with COPD and 12 healthy age-matched controls were analysed. Total antioxidant capacity, vitamin E, glutathione, and uric acid levels were determined and the enzyme activities of superoxide dismutase, glutathione reductase, glutathione peroxidase, and glutathione-S-transferase were measured. Malondialdehyde was measured as an index of lipid peroxidation. The total antioxidant capacity and the uric acid levels were markedly higher in COPD patients than in healthy controls (25%, P = 0.006 and 24%, P = 0.029, respectively). Glutathione-S-transferase activity was also increased (35%; P = 0.044) in patients compared to healthy subjects. Vitamin E level was lower in patients than in controls (P < 0.05). The malondialdehyde level was not different between the two groups. It can be concluded that the muscle total antioxidant capacity is increased in patients with COPD. Together with the reduced vitamin E levels, the increased glutathione-S-transferase activity and normal levels of lipid peroxidation products, these findings suggest that the antioxidant system may be exposed to and subsequently triggered by elevated levels of reactive oxygen species.

Aged↗
PubMed2003

Striking similarities in systemic factors contributing to decreased exercise capacity in patients with severe chronic heart failure or COPD.

AIMS: Chronic heart failure (CHF) and COPD are both characterized by muscular impairment. To assess whether the severity and functional consequences of muscular impairment are disease specific, we compared skeletal muscle function, body composition, and daily activity level relative to exercise capacity between these two disorders. METHODS: Twenty-five patients with CHF and 25 patients with COPD, and 36 healthy gender- and age-matched control subjects underwent measurement of fat-free mass (FFM) [by bioelectrical impedance analysis] as an index of muscle mass. Quadriceps and biceps functions were tested by isokinetic methods, and daily activity level was assessed by the Physical Activity Scale for Elderly (PASE) questionnaire. Peak oxygen consumption (O(2)peak) was measured by incremental cycle ergometry. RESULTS: PASE results were similar in patients with CHF and in patients with COPD, each group scoring lower than control subjects. FFM was also lower in patients than control subjects and correlated closely with quadriceps and biceps strength in all three subgroups, R values ranging from 0.63 to 0.78, with identical slopes. FFM also correlated significantly with O(2)peak (p < 0.05), but slopes were less steep in patients than in control subjects. The type and severity of muscle dysfunction were similar in each group of patients. There were no significant correlations between indexes of cardiopulmonary function and muscle function or exercise performance in patients with CHF or in patients with COPD. In both control subjects and patients, FFM was the most significant determinant of O(2)peak. CONCLUSION: Muscle dysfunction is not limited to the lower limbs, but generalized and comparable between patients with CHF and patients with COPD with similar exercise capacity. FFM is a strong predictor of peripheral muscle strength, to a lesser extent of O(2)peak, and not at all of peripheral muscle endurance.

Activities of Daily Living↗
PubMed2002

Muscle fiber type IIX atrophy is involved in the loss of fat-free mass in chronic obstructive pulmonary disease.

BACKGROUND: Although the loss of peripheral muscle mass has been shown convincingly in chronic obstructive pulmonary disease (COPD), the underlying pathogenesis remains unclear. OBJECTIVE: The aim of the present study was to determine the relations between skeletal muscle fiber types, fiber cross-sectional area (CSA), enzyme activities, and fat-free mass (FFM) in patients with COPD and in control subjects. DESIGN: In 15 patients with COPD and 15 healthy, age-matched control subjects, FFM was determined by dual-energy X-ray absorptiometry and bioelectrical impedance analysis. In biopsy specimens from the vastus lateralis fiber types, fiber CSA and activities of cytochrome oxidase (EC 1.9.3.1), succinate dehydrogenase (EC 1.3.99.1), and glycogen phosphorylase (EC 2.4.1.1) were examined immunohistochemically and histochemically. RESULTS: Compared with control subjects, patients with COPD had less FFM (49 compared with 59 kg, P = 0.030) and lower mean fiber CSA (3839 compared with 4647 microm(2), P = 0.037). A strong correlation (r = 0.87, P < 0.001) was observed between the FFM measured by bioelectrical impedance analysis and mean fiber CSA in patients with COPD. Within fiber-type categories the mean CSA of only the IIA/IIX and IIX fiber types was lower in patients than in control subjects [3358 compared with 4428 microm(2) (P = 0.022) and 2566 compared with 4248 microm(2) (P = 0.003), respectively]. In COPD, 20% of the type IIX fibers lacked stainable activities of cytochrome oxidase, succinate dehydrogenase, and glycogen phosphorylase, and this proportion correlated negatively with type IIX fiber CSA (r = -0.65, P = 0.012). CONCLUSIONS: Muscle fiber atrophy occurs in the vastus lateralis in patients with COPD and contributes to the loss of muscle mass in COPD. Atrophy is specific to fiber types IIA/IIX and IIX and is associated with a disturbed metabolic capacity.

Aged↗