摘要:

The steady-state responses of upper-airway dilating muscles and diaphragm activity to elevation of lung volume induced by positive end-expiratory pressure loading were studied in 9 pentobarbital-anesthetized dogs with vagus nerves intact. The early and late effects of 5 min of expiratory threshold loads upon upper airway dilating muscle activity (the alae nasi, the genioglossus and the posterior cricoarytenoid) were compared to their effects on diaphragm activity. During resting O2 breathing, application of 5 and 10 cm H2 0.05). No qualitative differences were found in the upper-airway dilating muscles and diaphragm responses to expiratory threshold loads when the animals breathed 3 or 7% CO2 in O2, compared to when they inspired 100% O2. Furthermore, no differences were found in the electrical activity of the upper-airway dilating muscles and diaphragm at any given end-tidal CO2 when unloaded responses were compared with loaded responses during progressive hypercapnia. However, positive end-expiratory pressure loading caused significant prolongation of expiratory duration, which gradually returned toward control levels when the loads were maintained. In animals who developed periodic breathing by increasing levels of anesthesia, positive end-expiratory pressure loading eliminated the periodicity and made the pattern of breathing regular. Based on these results, it can be concluded that under the conditions of these experiments, increases in lung volume produced by expiratory threshold loads do not reduce the activity of upper-airway dilating muscles. The maintenance of the electrical activity of the upper-airway dilating muscles might be caused by excitatory reflex mechanisms or central habituation.

ISSN:0025-7931    

DOI:10.1159/000195771

出版商:S. Karger AG    

年代:1989

数据来源: Karger

摘要:

237 out-patients suffering from chronic obstructive lung disease (COLD) were selected from 7 Italian clinical centers. They were randomly allocated to either placebo or bromhexine 30 mg b.i.d. p.o., in a double-blind fashion. Sputum volume and quality, facility of expectoration, cough, dyspnea, auscultatory thoracic symptoms, forced expiratory volume, peak expiratory now rate and residual volume were evaluated. Bromhexine showed a statistically significant therapeutic activity in comparison to placebo. This action was rapid, marked and effective in determining a modulation of bronchial secretions.

ISSN:0025-7931    

DOI:10.1159/000195772

出版商:S. Karger AG    

年代:1989

数据来源: Karger

摘要:

A single blind, cross-over study was performed in 12 male, nonsmoker, stable asthmatics, to assess the bronchodilatory responsiveness attributable to sympathetic and parasympathetic mechanisms. Serial doses of one agent (salbutamol or ipratropium) were administered to the supramaximal level to produce the maximum achievable bronchodilatation; thereafter, the other drug was given. The sequence was reversed on the 2nd day. On the 3rd day, both drugs were given together from the very beginning. Significant initial bronchodilatation was observed with either agent given alone, but was more marked with salbutamol. Further additional bronchodilatation was seen when salbutamol was administered after ipratropium, but not with ipratropium given after salbutamol. It was concluded that all achievable bronchodilatation was obtained with the adrenergic agent (salbutamol) given alone and that the dominant autonomic control of bronchomotor tone in bronchial asthma is through adrenoceptors.

ISSN:0025-7931    

DOI:10.1159/000195773

出版商:S. Karger AG    

年代:1989

数据来源: Karger

摘要:

The principal clinical pulmonary findings were extracted from University of Michigan Hospital records of 390 patients with scleroderma. Dyspnea was the most frequent symptom and strongly correlated with pulmonary fibrosis and with decreased vital capacity (FVC) and CO diffusing capacity (DLCO). The mean value for FVC was 84% of the predicted normal for 326 patients, and that of the initial DLCO 56.8% of the predicted normal (323 patients). Pulmonary fibrosis was diagnosed on first chest X-ray in’80 of 382 patients. An additional 48 patients developed fibrosis detected on subsequent X-rays.Analyses were performed to determine whether the deterioration of pulmonary function over time was less for scleroderma patients who were adequately treated with potassium p-aminobenzoate (KPAB) than for those inadequately or never treated with KPAB, The average decrease for both FVC and DLCO was found to be less for KPAB-treated patients. However, only in the case of vital capacity was the difference significant. In the presence of radiological evidence of pulmonary fibrosis FVC decreased more rapidly (p = 0.002), but the decline in DLCO was not affected. When adjusting for the presence or absence of fibrosis the average slopes of the logarithm of vital capacity were significantly less negative (p = 0.003) for patients on KPA

ISSN:0025-7931    

DOI:10.1159/000195774

出版商:S. Karger AG    

年代:1989

数据来源: Karger

摘要:

In 6 normal and 7 obstructed excised human lungs the interrupter resistance (APTA, Jaeger Company) with an airway occlusion period of 100 ms was determined, by measuring the equivalent of the alveolar pressure at the end of the occlusion period. To check the pressure equilibration between the tracheal pressure and the alveolar space, catheters were put in the most peripheral layer of the lung. The lungs were ventilated in an artificial thorax. The airway resistance determined from the transbronchial pressure difference by the catheters was taken as a reference. Compared with the reference method, an overestimation of the airways resistance by the interrupter technique in normal lungs was found which was caused by an overshoot of the pressure equilibration during the occlusion period. In contrast, in severely obstructed lungs the pressure equilibration was not complete which led to an underestimation of the airways resistance by the interrupter technique. The best approximation of the airways resistance by the interrupter method was found in lungs with a low degree of obstruction.

ISSN:0025-7931    

DOI:10.1159/000195775

出版商:S. Karger AG    

年代:1989

数据来源: Karger

摘要:

The immunoalkaline phosphatase procedure is described as a method for labelling bronchoalveolar lavage cellular specimens with monoclonal antibodies. This method has several advantages over conventional immunofluroescent techniques: it can be performed on cytocentrifuge preparations stored for long periods before staining; cell morphology can be observed in detail in positive and negative cells; the staining is permanent and stable, and, the reaction can be evaluated with a light microscope. Normal values for lymphocyte subpopulations in smokers and nonsmokers are also reported.

ISSN:0025-7931    

DOI:10.1159/000195776

出版商:S. Karger AG    

年代:1989

数据来源: Karger

摘要:

The sheep model of allergic airway disease shares many pathophysiological similarities with allergic airway disease in humans. Studies performed in this animal model present strong evidence that the release of arachidonic acid metabolites plays an important role in the development of late bronchial responses to antigen challenge. The release of leukotrienes through the lipoxygenase pathway during the acute bronchial obstruction after inhalation of Ascaris suum antigen represents the key factor for the initiation of the subsequent events, namely the late phase response and the bronchial hyperreactivity. If this hypothesis can be substantiated in patients with bronchial asthma then pharmacologic modification of the lipoxygenase pathway and/or products may be important in the treatment of asthma.

ISSN:0025-7931    

DOI:10.1159/000195777

出版商:S. Karger AG    

年代:1989

数据来源: Karger

摘要:

Haemodynamic and heart weight parameters were compared in male rats exposed to intermittent high-altitude (IHA) hypoxia (barochamber, 8 h/day, 5 days/ week, total of 24 exposures stepwise up to 7,000 m) starting either from the 4th day or the 12th week of postnatal life. Systemic arterial pressure and heart rate increased in adult IHA acclimatized animals only. Marked chronic pulmonary hypertension and right ventricular enlargement were found in both age groups. Right ventricular weight increased linearly with a rise of pulmonary blood pressure in animals exposed to IHA from the 4th day of life (r = 0.72); no significant relation was found in adult rats (r = 0.16). The close correlation between both variables in young hypoxic rats may be due to the ability of the developing heart to respond to chronic hypoxia by both hypertrophy and hyperplasia of myocytes.

ISSN:0025-7931    

DOI:10.1159/000195778

出版商:S. Karger AG    

年代:1989

数据来源: Karger

摘要:

Ventilatory responses and breathing patterns during acute hypoxia have been studied at sea level in healthy subjects (8 children, 8 adults). While breathing ambient air it appears that, compared to adults, children hyperventilate when ventilation is standardized to body mass unit. During hypoxia, ventilatory strategy differs with age: when adults essentially increase tidal volume (VT), children increase VT and ventilatory frequency (fr). The ventilatory steady-state response to hypoxia is lesser in children than in adults, that is to say, children have a lower O2 ventilatory sensitivity. These results, which show that adults and children have qualitatively and quantitatively different ventilatory responses to hypoxia, are interpreted in terms of the ability to displace gaseous volumes.

ISSN:0025-7931    

DOI:10.1159/000195779

出版商:S. Karger AG    

年代:1989

数据来源: Karger

摘要:

Tracheobronchial clearance and bronchial reactivity were studied in 6 asthma-discordant monozygotic twin pairs, and in 3 concordant pairs as controls. Clearance of 6-µm Teflon particles labeled with 99mTc was followed for 2 h. The results indicate that clearance in the larger airways is usually not severely impaired in mild to moderate asthma, and that it may be increased as well as decreased. Bronchial reactivity correlated with clearance in the nonasthmatics

ISSN:0025-7931    

DOI:10.1159/000195780

出版商:S. Karger AG    

年代:1989

数据来源: Karger