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Biomedical subjects

H Bachofen

Publications and source records attributed to H Bachofen.

At least 73 records · Page 4Linked to original sources
PubMed1978

Adaptation of the growing lung to increased Vo2: III. The effect of exposure to cold environment in rats.

This study was undertaken to further test the hypothesis that increased Vo2 operates as a stimulus for enhanced lung growth leading to a pulmonary diffusing capacity adapted to the body's O2 requirements. Vo2 was augmented by raising 4-week-old rats for 3 weeks at 11 degrees C ambient temperature, with controls kept at 24 degrees C; this led to an increase in Vo2 averaged over 24 h by 64%. In contrast to previous experiments with waltzing mice this regime did not affect body growth, as the final body weights were identical in both groups. In the cold-exposed rats the lung volume was larger by 24%, due to an increase by 26% in air volume (at about TLC), 13% in capillary blood volume and 19% in tissue volume. The alveolar and capillary surface areas were increased by 18%, and Dm and Dl by 17% and 21% respectively. It is concluded that the hypothesis of adaptation of pulmonary gas exchange capacity to increased Vo2 cannot be rejected. Whilst in previous experiments some doubts had to be retained as to the specificity of the stimulus, because of its rather marked effect on body weight, this reservation does not hold in this case. The structural modifications which lead to increased Dl in the various experimental models are discussed.

Adaptation, Physiological↗
PubMed1977

[Arterial CO2- and O2 partial pressure at rest and during exertion in pulmonary emphysema].

In 83 patients with severe, largely irreversible bronchial obstruction (FEV1/VC less than 40% and FEV1 after orciprenaline inhalation less than 120% of the control value) and radiologie evidence of AD-emphysema, arterial PCO2 and PO2 were measured at rest in supine position and on the bicycle ergometer during a steady-state exercice of 5 min. Alveolar hypoventilation (PCO2 greater than 45 mm Hg) was most often observed in the cases with FEV1 less than 1.01 (in 22 patients [27%] at rest and in 26 patients [31%] during exercise). However, there was no significant correlation of the PCO2 increase with the degree of bronchial obstruction. In all patients there was a marked inhomogeneity of the alveolar ventilation or the alveolar-capillary O2 transfer in relation to alveolar blood perfusion. Indeed, the alveolar-arterial PO2 difference was increased (40 mm Hg at rest and 45 mm Hg during exercise). The additional increase of this gradient during exercise was due to an unequal distribution of alveolar O2 diffusing capacities in connection with the alveolar blood flow (preceding measurements of the N2 gradient between alveolar air and arterial blood revealed a mean fall from 18 at rest to 8 mm Hg during exercise). The observed deterioration of hypoxemia during exercise (without additional hypercapnia) is to a great extent related to the degree of bronchial obstruction measured by simple spirometry. Thus, measurements of PCO2 and PO2 at rest and during exercise appear to be a helpful adjuvant to routine spirometry in the diagnosis of subclinical emphysema.

Arteries↗
PubMed1977

[Lung and pleural involvement in collagen disease (author's transl)].

Frequency and type of pulmonary and pleural involvement in collagen disease (rheumatoid arthritis, progressive systemic scleroderma, polymyositis-dermatomyositis and lupus erythematodes are analysed on the basis of literature and of own cases with particular regard to the roentgenographic appearance.

Adult↗
PubMed1976

[Measurement of the heart minute volume by means of the ether dilution method].

Ethyl ether dissolved in saline has been used as an indicator for measuring cardiac output in patients with various congenital and acquired valvular heart diseases without shunts. The solution was infused at a constant rate into the superior vena cava. By means of a simultaneous rebreathing maneuver it was possible to determine the ether concentration of the mixed venous blood and hence the dilution factor. Comparative measurements with the direct Fick method revealed a satisfactory accuracy of the ether dilution method (r = 0.94), which does not require sampling and analysis of mixed venous and arterial blood.

Cardiac Output↗
PubMed1976

[Lung neoplasms in the Berne region. Epidemiology and smoking habit, compared to histology].

223 lung cancer patients were observed from June 1974 to April 1976. The diagnosis was by histology (after biopsy, operation or autopsy). There were 125 (56%) squamous cell carcinomas (sqcc), 42 (19%) small cell carcinomas (smcc), 27 (12%) large cell carcinomas (lacc) and 29 (13%) adenocarcinomas (adec). There were only 6 women (2.7%) in the series (3adec, 2 smcc and 1 lacc). Heavy and very heavy smokers were common in each group; smoking habits--even of patients with adec - differed markedly (p less than 0.0005) from those of an age and sex matched control group of 90 asthmatic patients with atopy. Sqcc patients were evenly distributed over the rural and urban zones of our region. But smcc, lacc and adec were more often seen coming from urban zones (p less than 0.0025). The whole lung cancer group was divided into a small group of 6 non-smokers (2.7%), into a 6.7% group of 15 pipe smokers, into a large group of 69 cigar smokers (30.9%) and into a final group of 133 (59.6%) cigarette smokers. The cigar smokers usually had sqcc (p less than 0.0005). The cancer of cigar smokers is more often a central lesion than a peripheral one (p less than 0.025). A history of repeated airway infections on the one hand, and severe airway infection at the beginning of lung cancer history on the other, are a more frequent association in cigar smokers than in cigarette smokers (p less than 0.01). Therefore, the lung cancer of cigar smokers is especially difficult to recognize. Cigar smoking appears to be just as important a link in the chain of causative factors leading to lung cancer as cigarette smoking.

Adenocarcinoma↗
PubMed1976

Auto-oxidation of hemoglobin in plasma.

The rate of auto-oxidation of human hemoglobin to methemoglobin was measured in plasma at 37 degrees C. Half-lives of hemoglobin were found to be 20 h, 12 h and 7 h at the oxygen tensions of 126, 57 and 23 mm Hg, respectively.

Hemoglobins↗
PubMed1976

[Pulmonary vessel calibre on in- and expiratory chest radiographs in young and old normal people (author's transl)].

Changes in pulmonary blood flow as see on chest radiographs have assumed considerable importance recently in the evaluation of left ventricular insufficiency. In order to study the results of poor radiographs on the evaluation of pulmonary haemodynamics, blood-flow patterns were studied in 39 individuals of various ages during normal inspiration, during the Valsalva manoeuvre and during expiration. All had normal lungs. The results indicate that changes in blood-flow patterns and loss of marginal definition of basal vessels are unreliable signs of left-sided insufficiency in old patients or in unco-operative patients, in the presence of a high diaphragm and in the supine position.

Adult↗
PubMed1975

[Comparison of Tyloxapol (Tacholiquin, Alevaire) with physiological saline as inhalation carrier solutions].

By means of a double-blind crossover study the effects of tyloxapol (Tacholiquin, Alevaire) and saline as carrier solutions for the inhalation of beta-agonists have been compared in 24 paitents with bronchial asthma. Specific airway conductance was measured repeatedly over a 2-hour period in order to assess changes of airway caliber due to the inhalation. The results reveal a significant bronchoconstrictive effect of tyloxapol as compared with saline. The bronchodilator activity of solutions with tyloxapol and beta-agonists (orciprenaline, salbutamol) was no better than those with saline and the same beta-agonists. However, side effects (symptoms of airway irritation, increase of pulse rate) were more pronounced with tyloxapol. In view of the direct effects of inhalation with a beta-agonist, no advantage of the expensive carrier solution tyloxapol over saline could be shown.

Albuterol↗
PubMed1975

[Significance of a negative inhalation test in chronic obstructive lung disease].

To assess the bronchospastic component in patients with chronic obstructive lung disease, measurement of vital capacity and forced expiratory volume (FEV) before and after inhalation of a beta-agonist is a widely used procedure. In a minority of patients this simple inhalation test yields a negative result, suggesting the possibility of unresponsive airways. The purpose of this study was to explore th significance of a negative test result by examining pulmonary mechanics in 17 patients before and after inhalation. The results permit the following conclusions: (1) A significant broncholytic action of a beta-agonist can be determined by measuring vital capacity and FEV. As a rule, a negative test cannot be attributed to the alleged insensitivity of spirometric measurements. For clinicla purposes, the more demanding determination of specific airway conductance is not necessary. (2) A negative inhalation test does not imply a pure emphysema with out peripheral airway disease, any more than it does irreversible bronchiolitis. All it proves is the unimportance of bronchiolospasm at the time of examination. The true role of a spatic component in the course of the disease, and the benefit of regular inhalations, can be assessed on the basis of repeated controls only.

Aged↗
PubMed1975

[The inhalation of beta stimulators. Effect of the inhaled aerosol deposited in the oropharynx and in the bronchial tree].

Inhaled aerosols are predominatly deposited in the oropharynx and only a minor portion penetrates into the sublaryngeal airways. The effectiveness of both components of an orciprenaline aerosol was tested in 12 asthmatics. For this purpose they were given an inhalation on one day and, on the next, the entire oropharynx was sprayed with the inhalant. Evaluation of the corresponding bronchodilator effects was based on repeated measurements of specific airway conductance. The results show that the inhalation is about 6 times as effective as the spray, and thus prove the superiority of inhalation therapy over oral or peroral medication with beta-stimulants in the treatment of bronchial asthma.

Adult↗