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Biomedical subjects

B Mossberg

Publications and source records attributed to B Mossberg.

65 records · Page 4Linked to original sources

Working capacity and cardiopulmonary function after extensive lung resections.

Twelve patients were investigated 7-168 months after pneumonectomy. Two of them had also undergone resection of a segment of the remaining lung. The follow-up included studies of working capacity, static and dynamic lung volumes, alveolar gas exchange, diffusing capacity, blood gases and central haemodynamics with right heart catheterization. The working capacity was markedly reduced, limited by dyspnoea in 10/12 patients. The dyspnoea was related to reduced static and dynamic lung volumes (50% of normal). The diffusing capacity of the remaining lung was half of that predicted for two lungs from total haemoglobin and age and the transfer capacity of the lungs for oxygen was loaded to its maximum even at submaximal loads, resulting in a decrease in arterial oxygen tension and saturation and an increase in the alveolo-arterial oxygen tension difference. The central circulation was hypokinetic at submaximal loads and the stroke volume was small. The reduction in working capacity was caused by a number of coacting factors, inactivity, reduced lung function and small stroke volume. It was not possible from the present investigation to single out any of these factors as the main cause of dyspnoea during exercise and thereby the reduced working capacity.

Adult↗

Tracheobronchial clearance and beta-adrenoceptor stimulation in patients with chronic bronchitis.

The effect of a beta-adrenoceptor stimulating agent, terbutaline, on mucociliary transport in the lungs was studied in 10 patients with chronic bronchitis. Mucociliary transport was studied by having the patients inhale 6mum teflon particles tagged with 99mTc and by external measurement of the radioactivity in the lungs in the supine position. Terbutaline 0.25 mg and vehicle respectively were given subcutaneously in a cross-over double-blind study. On the average, clearance was slow in the examinations where the patients were given vehicle. Terbutaline produced a marked increase in mucociliary transport in four patients, a smaller increase in one and no effect in the others. Three out of the four patients who showed a marked inrease in clearance had less ventilatory impairment than the other seven patients. This may indicate that the mucociliary transport mechanism is less severely damaged in relatively early stages of the disease than in later stages. On the average FEV1.0 deteriorated significantly during the clearance measurements when vehicle was given, but did not change significantly when terbutaline was given.

Adult↗

Tracheobronchial clearance in bronchial asthma: response to beta-adrenoceptor stimulation.

Tracheobronchial clearance was studied in 12 patients with bronchial asthma. They inhaled a test aerosol of 6 mum teflon particles tagged with 99mTc, after which external measurement of the radioactivity in the lungs was made for 2 h in the supine position. Clearance was determined after subcutaneous administration of 0.25 mg of the beta-adrenoceptor stimulating compound terbutaline and vehicle, respectively, in a crossover, double-blind study. The average clearance in the asthmatics did not differ significantly from that of healthy non-smokers. Terbutaline significantly enhanced clearance in the asthmatics, though considerably less than reported for healthy subjects. Alternative explanations for this weak effect of terbutaline in the asthmatics might be that the mucociliary transport system was affected by the asthma disease, or that earlier treatment with beta-adrenoceptor stimulating compounds or other drugs had produced increased tolerance and/or carry-over effects. Ventilatory function measured as FEV1.0 deteriorated significantly during the clearance measurement when vehicle was given, but not when terbutaline was given. Terbutaline thus counteracted the unfavourable effect of the supine position on ventilation.

Adult↗

Evidence of congenitally nonfunctioning cilia in the tracheobronchial tract in two subjects.

Mucociliary transport in the tracheobronchial tract was studies in 2 subjects by having them inhale a radioactively tagged test aerosol and by taking external measurements of the radioacitivity in the lungs for 2 hours. Both subjects had living, yet immotile seprmatozoa; the sperm tails lacked normal dynein arms, which are essential for the bending movements of sperm tails as well as of other cilia. The subjects were classified as suffering from Kartagener's syndrome (situs inversus, chronic sinusitis, and bronchiectasis) and were shown to have an extremely slow, probably absent transport. The results of the study were in agreement with a recent hypothesis explaining Kartagener's syndrome as due to a genetic lack of dynein arms. An estimate of the importance of mucociliary transport as a protective mechanism of the lung may be possible by examining patients suffering from Kartagener's syndrome.

Adult↗

Otologic manifestations of the immotile-cilia syndrome.

The immotile-cilia syndrome is caused by a hereditary, inborn, ultrastructural defect of the cilia, rendering them immotile or poorly motile and thereby abolishing mucociliary clearance. Five cases are presented and the otologic manifestations are described in some detail. The syndrome should be suspected in children who have a persistent secretory otitis media with recurring bouts of acute otitis media, and a perpetual cough with repeated episodes of bronchitis. A lobar atelectasis is a frequent finding. Half the cases also have situs inversus. The immotile-cilia syndrome is of special interest to the otologist, as it seems to throw some light on the pathogenesis of secretory otitis media.

Adolescent↗

Deposition and clearance in large and small airways in chronic bronchitis.

Tracheobronchial clearance was studied twice in 16 patients with chronic obstructive bronchitis after inhalation of 6 microns (aerodynamic diameter) monodisperse Teflon particles labeled with 111In. At one exposure the particles were inhaled at an extremely slow flow, 0.05 L/s; at the other they were inhaled at a normal flow, 0.5 L/s. Theoretical calculations and experimental data in healthy subjects indicate particle deposition mainly in the smallest ciliated airways using 0.05 L/s, i.e., in the bronchiolar region, and an enhanced deposition in larger airways using 0.5 L/s. Lung retention was measured at 0, 24, 48 and 72 h. Clearance was significantly every 24 h for both exposures (p < .05). The fractions of retained particles were significantly larger for particles inhaled at 0.05 L/s compared to 0.5 L/s at all points of time (p < .001). Compared to healthy subjects, the retained fractions of deposited particles were larger in patients with bronchitis breathing at 0.05 L/s, but smaller with breathing at 0.5 L/s (p < .01). Significant relationships were found between lung retentions and airway resistance (Raw) at 0.5 L/s, r = -.68 (p < .01), but not at 0.05 L/s, and between lung retention at 24 h and weight of expectorated sputum at 0.05 L/s, r = -.50 (p < .05). There was, furthermore, an almost significant relationship between sputum volume and rate of tracheobronchial clearance between 0 and 24 h (in percentage of the total amount cleared during 72 h) at 0.05 L/s, r = .42 (p = .05). The results indicate that in patients with chronic bronchitis overall clearance of particles in small airways is incomplete, as compared to larger airways. An increased amount of mucus, however, seemed to improve clearance of peripherally deposited particles, possibly by making cough more effective in small airways.

Adult↗