摘要:

The presence of pulmonary, cerebral, and/or peripheral edema in acute mountain sickness (AMS) implies a derangement in the body’s handling of water. Previously, we demonstrated water retention and increased symptoms of AMS when hypocapnia was prevented in subjects exposed to simulated high altitude. This led us to the hypothesis that upon ascent to high altitude, those persons who fail to increase their ventilation adequately and hence do not become hypocapnic will retain water reflected as weight gain and will develop AMS. To test this hypothesis, we studied in Kathmandu, Nepal (1,377 m) 42 healthy western tourists; all were restudied in Pheriche (4,243 m) within 6 days of exposure to high altitude. Symptoms of AMS were highly correlated (p < 0.001) with weight change, suggesting that persons becoming symptomatic retained fluid. On going from low to high altitude, those persons who lost weight and remained well increased their resting ventilation, whereas those who gained weight did not (p = 0.03). This relative hypoventilation in the latter group was confirmed by higher values of Pco2 (heated hand vein blood) and lower values of arterial saturation (ear oximeter) at Pheriche. Vital capacity measured in Kathmandu was correlated with arterial saturation at Pheriche (p = 0.02); persons with low vital capacity were more hypoxemic with more symptoms of AMS. We conclude that relative hypoventilation and weight gain appear early in the development of AMS suggesting links between altitude hypoxia, hyperventilation, hypocapnia, and the body’s handling of wa

ISSN:0025-7931    

DOI:10.1159/000194501

出版商:S. Karger AG    

年代:1982

数据来源: Karger

摘要:

Lung diffusing capacities for carbon monoxide were measured in 125 highland Andean children between 4 and 6 years of age in La Paz, Bolivia (3,650 m), using a steady-state technique. Male children had a significantly lower DLC0 (13.2 ± 2.7) compared to females (14.2 ± 1.9; p < 0.05), despite similar body size Hemoglobin concentration was significantly greater than published values for low-altitude children and this also changes pulmonary diffusing capacities and supports the concept of early developmental adaptation in pulmonary function to environmental stressors as well as a sexual dimorphism in this type of adaptatio

ISSN:0025-7931    

DOI:10.1159/000194502

出版商:S. Karger AG    

年代:1982

数据来源: Karger

摘要:

45 patients with chronic obstructive lung disease and chronic respiratory insufficiency were studied. The investigation of these hypoxemic patients concerned the compensating mechanisms in the oxygen transport. The study was performed at rest, during exercise and after 100% oxygen breathing. Normal values for the calculated oxygen consumption (VO2) and cardiac output (Q) were found. Low values of arterial oxygen pressure (PaO2) were compensated by a decrease of the venous oxygen pressure (PvO2) normalizing the arteriovenous oxygen saturation difference (Sa-v)· In patients with very low values of PaO2 a further decrease of PvO2 was not established. In these patients, Sa-v became smaller and an increase of the hemoglobin concentration resulted as a compensating mechanism. During exercise, a shift to the right of the oxygen dissociation curve took place as an added compensation

ISSN:0025-7931    

DOI:10.1159/000194503

出版商:S. Karger AG    

年代:1982

数据来源: Karger

摘要:

A study of systolic intervals in 22 cases of chronic obstructive pulmonary disease (COPD) reveals that the respiratory illness tends to shorten both the isometric contraction (ICT) and the ejection time (LVET). The authors discuss possible pathophysiological interpretations of such findings and conclude that these modifications are not imputable to impaired left ventricle contractility; rather, they seem to reflect the effects on left ventricle geometry of the morphologic and functional alterations produced by the background respiratory pathology in the right ventricle.

ISSN:0025-7931    

DOI:10.1159/000194504

出版商:S. Karger AG    

年代:1982

数据来源: Karger

摘要:

The oto-respiratory (O-R) reflex consists of the cough reflex produced by direct mechanical stimulation of the deep portion of the posterior wall of the external auditory meatus. Because the efferent pathways are different for coughing and bronchoconstriction, some subjects can have an O-R reflex (coughing) without the oto-bronchial (O-B) reflex (bronchoconstriction). This study also states that on stimulation of the mechanoreceptors in the external ear, 20 out of 125 normal subjects (16%) presented with the O-R reflex; in 7 of the 20 subjects, bronchoconstriction (‘responders’) was also documented (O-B reflex). The O-B reflex was particulary evident in 3 of the 7 responders. These normal subjects referred a family history of atopy. Only through animal experimentation can the exact nervous pathway of the O-R reflex be defined. From the physiological point of view, it is difficult to imagine how this ‘irritative’ reflex could have a protective function against auditory agg

ISSN:0025-7931    

DOI:10.1159/000194505

出版商:S. Karger AG    

年代:1982

数据来源: Karger

摘要:

We examined 10 patients with an exercise-induced asthma. Physical exercise was carried out under placebo, 40 mg propranolol, 5 mg pindolol and 50 mg metoprolol, respectively, before and after alpha blockade. After exercise, we noted a distinct increase of airway resistance in all cases, the increase of which, however, was lower after a preceding alpha blockade. Under propranolol, the increase of the airway resistance and of norepinephrine, as compared with pindolol, metoprolol, and placebo, was most intensive.

ISSN:0025-7931    

DOI:10.1159/000194506

出版商:S. Karger AG    

年代:1982

数据来源: Karger

摘要:

The techniques of light and electron microscopy were used to study the sequence of changes in the fine structure of the developing nonciliated bronchiolar cells in the last quarter of gestation in the mouse, and up to the 3rd postnatal day. Control animals were compared with two groups that received either dexamethasone or ambroxol. At the beginning of the study no identifiable Clara cells were seen in any group, and phenotypically differentiated cells were seen until 1 day post partum in every group examined. Dexamethasone appears to increase the glycogen deposition found in the cells, reaching its maximum 1 day prior to delivery. Ambroxol induced an earlier development of the secretory organelles, beginning on day 17 of gestation. In the differentiated cells more secretory dense granules were found in this group; and at the 3rd day post partum a great accumulation of secretory product that filled large areas of cytoplasm was seen only in the ambroxol-treated group. The significance of these finding is discussed.

ISSN:0025-7931    

DOI:10.1159/000194507

出版商:S. Karger AG    

年代:1982

数据来源: Karger

摘要:

The techniques of light and electron microscopy were used to study the morphogenesis and cytodifferentiation in the last quarter of fetal development of the mouse lung and the early postpartal stage up to the 3rd day. Animals treated transplacentally with either dexamethasone or ambroxol were compared to control groups. The dexamethasone-treated group showed acceleration of development, both in the morphogenesis and cytodifferentiation. The ambroxol-treated group showed a selective stimulation of development of the organelles related to surfactant secretion, as well as signs suggestive of an active release of it, as judged by the presence of abundant electron-dense osmiophilic material within the alveolar lumen as well as by the ultrastructural features of the identifiable type II pneumocytes.

ISSN:0025-7931    

DOI:10.1159/000194508

出版商:S. Karger AG    

年代:1982

数据来源: Karger