摘要:

The hypoxia of high altitude stimulates ventilation. If the resultant respiratory alkalosis inhibits the initial increase in ventilation, then with prevention of alkalosis, ventilation should rise immediately to a stable plateau. 4 subjects inspired CO2 (3.77%) from ambient air in a hypobaric chamber (PB = 440–455 Torr) during 100 h at high altitude. Ventilation (for given oxygen uptakes at rest and during exercise) increased promptly and remained stable. 4 control subjects exposed to high altitude without CO2 supplementation showed the expected progressive increases in ventilation with time. The hyperoxic CO2 ventilatory response curve shifted progressively to the left with time in the control subjects, but not in those given supplemental CO2. The latter group also failed to increase the ventilatory response to isocapnic hypoxia. Thus, CO2 supplementation at high altitude prevented the so-called ‘ventilatory acclimatization’ from occurring. Prevention of respiratory alkalosis at high altitude probably permitted maintenance of [H+] at some central nervous system locus, thus allowing an uninhibited hypoxic stimulation of venti

ISSN:0025-7931    

DOI:10.1159/000194206

出版商:S. Karger AG    

年代:1980

数据来源: Karger

摘要:

β -Adrenergic mimetics and blockers, as well as a local anesthetic (xylocaine) were infused into the vertebral artery of paralyzed and artificially ventilated cats. The effects of the drugs on the central control of ventilation was assessed by measuring the changes in phrenic nerve activity. β -Mimetics [isoprenaline (1 and 2) Prenalterol (1) made the phrenic nerve activity increase; β-blockers propranolol (1 and 2), metroprolol (1), oxprenolol (1 and 2)] decreased the phrenic nerve activity. β2-Mimetics (Salbutamol) and blockers (Butoxamine, H 35/35) had no clear effects. The mode of action of the β-blockers is most probably not by their local anesthetic properties. It is concluded that β-adrenergic mechanisms in the brain stem stimulate the ventilatory control system. The receptors are most probably β1-re

ISSN:0025-7931    

DOI:10.1159/000194207

出版商:S. Karger AG    

年代:1980

数据来源: Karger

摘要:

Steady state ventilatory response curves to CO2 were taken in 8 normal subjects in control situations and taking clinical doses of propranolol, oxprenolol and metoprolol in a double-blind crossover design. Furthermore, the expiratory peak flow was measured. No effect was found of any of the β-blockers on the resting ventilatory parameters, the sensitivity to CO2 or the peak flow value

ISSN:0025-7931    

DOI:10.1159/000194208

出版商:S. Karger AG    

年代:1980

数据来源: Karger

摘要:

The distribution of afferent and efferent nerves to the lung has been studied using dogs anaesthetised with chloralose in which the lungs had been separated, enabling independent inflation and measurement of lung mechanics. Reflex bronchoconstriction produced by giving an aerosol of 5-hydroxytryptamine (5HT) or histamine to either the right or left lung failed to elicit a change in resistance (RL) of the contralateral lung. In vagotomised dogs, electrical stimulation of the peripheral end of the left or right cervical vagus produced frequency-dependent increases in RL of the ipsilateral lung. Stimulation of the left vagus also produced significant changes in RL of the right lung

ISSN:0025-7931    

DOI:10.1159/000194209

出版商:S. Karger AG    

年代:1980

数据来源: Karger

摘要:

Volatile aromatics, eucalyptol, eucalyptus oil, camphor and menthol were spread on synthetic DPL films and pulmonary surfactants; the initial surface pressure of the surfactants was measured and the additional surface pressure increment recorded. Eucalyptol was allowed to be inhaled by rabbits and lung compliance was monitored. Under our experimental conditions the volatile aromatics exhibited surfactant-like effects, namely a decrease in surface tension between water and air and thus improved lung compliance values in vivo

ISSN:0025-7931    

DOI:10.1159/000194210

出版商:S. Karger AG    

年代:1980

数据来源: Karger

摘要:

We have studied 40 workers with varying industrial exposure to asbestos, using routine spirometry and maximal expiratory flow volume curves (MEFVC). Abnormalities of MEFVC were common and seen in those with normal spirometry and total lung capacity. The high incidence of abnormal MEFVC suggests that air flow dysfunction in small airways may follow prolonged asbestos exposure. Our findings support, therefore, the idea that asbestos exposure may cause an obstruction to airflow arising particularly in small airways, and that one of the common functional abnormalities attributable to asbestos exposure is airways obstruction

ISSN:0025-7931    

DOI:10.1159/000194211

出版商:S. Karger AG    

年代:1980

数据来源: Karger

摘要:

In patients undergoing thoracotomy for carcinoma of the bronchus, a maximum mid-expiratory flow rate of less than 1.2 litres/sec and the operation involving right pneumonectomy have been shown to be factors associated with an increased risk of post-operative cardiopulmonary complications. These two criteria are combined with previously reported empirical limits for lung volume and ventilation values to give a new method of postoperative risk prediction. The improved method gave incorrect forecasts in only 46 of a series of 240 routinely referred patients compared with 90 by the earlier method. In a further series of the same number, only 32 patients were incorrectly forecast. The method is therefore recommended to classify patients as at either below-average, average, or above-average risk of function-related complications in future pre-operative assessments

ISSN:0025-7931    

DOI:10.1159/000194212

出版商:S. Karger AG    

年代:1980

数据来源: Karger

摘要:

Concentrations of albumin, IgG, IgA, IgM, α1-acid glycoprotein, α1-anti-trypsin, α2-macroglobulin, transferrin, haptoglobin, and coeruloplasmin were determined by radial immunodiffusion in the blood sera and bronchial washings of 8 patients without clinical, radiologic or bronchoscopic evidence of lung diseases. The local production of the proteins was calculated with a formula used by Deuschl and Johansson for the estimation of local synthesis of bronchial immunoglobulins. The formula was completed by a reduction factor established by the authors, based on their previous investigations The calculations indicated that the individual proteins were secreted locally in various percentages of the total amount found in the secretion, as follows: IgG, 37%; IgA, 84.5%; transferrin, 44.5%, α1-antitrypsin, 15.2%; coeruloplasmin, 11.3%. Local synthesis of IgM was found only in 3 patients. The α1-acid glycoprotein and the haptoglobin do not seem to be secreted locally by the normal bronchial mucosa; they reach the mucus from blood only, through ultrafiltr

ISSN:0025-7931    

DOI:10.1159/000194213

出版商:S. Karger AG    

年代:1980

数据来源: Karger

摘要:

High oxygen affinity hemoglobinopathy, as an eventual cause for polycythemia of undetermined etiology, was investigated in 40 unclassifiable polycythemia subjects. The determination of 2,3-diphosphoglycerate and P50 in the polycythemic and in the control groups has not demonstrated any significant difference between them. The routine search of this condition in similar patients does not seem to be warranted

ISSN:0025-7931    

DOI:10.1159/000194214

出版商:S. Karger AG    

年代:1980

数据来源: Karger

ISSN:0025-7931    

DOI:10.1159/000194215

出版商:S. Karger AG    

年代:1980

数据来源: Karger