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Biomedical subjects

H Magnussen

Publications and source records attributed to H Magnussen.

At least 271 records · Page 15Linked to original sources
PubMed1988

Methylxanthines inhibit exercise-induced bronchoconstriction at low serum theophylline concentration and in a dose-dependent fashion.

We studied the relationship between attenuation of exercise-induced bronchoconstriction and serum theophylline concentration in a dose-dependent fashion in 11 patients with mild bronchial asthma. In addition, we investigated the protection of equal amounts of theophylline either dissolved in ethylenediamine or in proxyphylline and diprophylline. At 4 separate study days, the patients received one of the following preparations in a double-blind random order: saline solution, 200 mg of theophylline in 19.9 mg of ethylenediamine (TE200), 351 mg of theophylline in 35 mg of ethylenediamine (TE351), and 200 mg of theophylline in 300 mg of propxyphylline and 300 mg of diprophylline (TPD). Fifteen minutes after the end of infusion, a standardized exercise test during cold air breathing was performed. Before and up to 30 minutes after each test, specific airway resistance and FEV, were determined. Postexertional bronchoconstriction after theophylline was expressed by means of a protection index, a value of 0 or 1 meaning no or full protection, respectively. At mean (SD) serum theophylline concentrations of 6.7 (1.3), 10.1 (1.7), and 6.3 (1.4) mg/L, respectively, TE200, TE351, and TPD for specific airway resistance caused a significant bronchodilation (p less than 0.05) and resulted in mean (SD) protection indices of 0.61 (0.15), 0.82 (0.14), and 0.65 (0.20), respectively, being significantly different from 0 (p less than 0.01). The protective effect of TE200 and TPD was equal and significantly less pronounced as compared to TE351 (p less than 0.01). Therefore, theophylline attenuated exercise-induced bronchoconstriction in a dose-dependent fashion with significant protection at serum concentrations of about 6 mg/L. The effect of intravenous theophylline was independent of the diluents.

Adolescent↗
PubMed1987

[Chemotherapy of pulmonary tuberculosis. Sputum culture conversion in 8 weeks in 84% of patients].

Conversion rate to negativity of sputum culture and microscopy in 50 patients, previously untreated, with open cavernous pulmonary tuberculosis was analysed. Treatment consisted of isoniazid, rifampicin and pyrazinamide for three months, followed by administration of isoniazid and rifampicin. Conversion to a negative sputum culture had occurred after four weeks in 30% of patients, after eight weeks in 84%, and after 14 weeks in all patients. In 76% of patients the cultural conversion preceded the microscopic one. Treatment was well tolerated; only one patient had side effects requiring a short interruption of drug administration. The results confirm that this regimen is effective against pulmonary tuberculosis without significant side effects.

Adolescent↗
PubMed1987

[Bronchography during flexible bronchoscopy. Indications and results in bronchiectasis].

The radiological imaging of the respiratory tract by bronchography has apparently lost in importance since the introduction of newer imaging methods. Indications for and results of bronchography, performed after bronchoscopy with a flexible bronchoscope under local anesthesia, were analysed in 115 patients. In 68 the bronchography had been performed because of suspected bronchiectasis, in the others because of hemoptysis, cough or infiltration of unclear etiology. In 43% of patients who had undergone bronchography bronchiectasis was indeed found, in 47% there were isolated or additional changes in the bronchial system. In 70% the examination had furthered the diagnosis. The described method of bronchography was not significantly more uncomfortable than flexible bronchoscopy alone. Combined bronchoscopy and bronchography is thus a valuable procedure in the diagnosis of pneumonological abnormalities.

Adolescent↗
PubMed1987

Theophylline has a dose-related effect on the airway response to inhaled histamine and methacholine in asthmatics.

To study whether theophylline inhibits airway hyperresponsiveness in a dose-dependent fashion, we performed inhalation challenges with histamine and methacholine in 9 asthmatic patients. On 4 separate days, 3 consecutive histamine or methacholine tests were carried out, each of them 20 min after saline (placebo) and after 100, 100, and 200 mg intravenous theophylline ethylenediamine given in a cumulative fashion. Airway responsiveness was expressed as the provocative dosage of histamine or methacholine necessary to increase specific airway resistance by 100% (PD100SRaw). After placebo PD100SRaw for histamine showed a small but significant (p less than 0.01) increase not observed after methacholine. Theophylline markedly attenuated airway reactivity in a dose-dependent manner. At a mean (SD) serum concentration of 6.14 (0.30) mg/L, theophylline increased geometric mean PD100SRaw for histamine from 2.76 to 6.07 units (p less than 0.01) and for methacholine from 1.52 to 2.60 units (p less than 0.05). At a mean (SD) serum concentration of 12.9 (0.70) mg/L, theophylline increased geometric mean PD100SRaw for histamine from 2.70 to 17.1 units (p less than 0.01) and for methacholine from 1.28 to 4.98 units (p less than 0.01). Thus, there was a protective effect of theophylline on histamine and methacholine responsiveness in patients with bronchial asthma at "subtherapeutic" serum theophylline concentrations with increasing efficacy at higher serum theophylline concentrations. These observations may have therapeutic implications in the treatment of patients with mild asthma.

Adolescent↗
PubMed1987

The inhibitory effect of azelastine and ketotifen on histamine-induced bronchoconstriction in asthmatic patients.

We studied the antihistaminic property of a new compound, azelastine, on histamine-induced bronchoconstriction and compared it with ketotifen and placebo. In 12 patients with bronchial asthma we performed histamine bronchial challenges before and four hours after ingestion of placebo, 2.0 mg ketotifen, and 4.4 mg azelastine given in a double-blind, randomized, cross-over fashion. Ketotifen and azelastine provided significant protection compared with placebo. No statistically significant difference between ketotifen and azelastine could be detected. As the antihistaminic effect of azelastine does not predict the therapeutic usefulness in the maintenance therapy of bronchial asthma, further studies are indicated.

Adult↗
PubMed1987

The acute effect of a single oral dose of 200 mg almitrine on gas exchange in patients with chronic obstructive bronchitis and emphysema, bronchial asthma and lung fibrosis.

We studied the acute effect of a single, oral dose of 200 mg almitrine and of placebo on arterial blood gas tensions, ventilation, gas exchange and pulmonary mechanics in 28 patients with chronic obstructive bronchitis and emphysema (COPD), 20 patients with bronchial asthma and 10 patients with interstitial lung disease. Almitrine significantly increased PaO2 in COPD, had a borderline effect in bronchial asthma and no effect in lung fibrosis. In all groups of patients almitrine significantly increased minute ventilation and decreased arterial carbon dioxide tension (PaCO2). Placebo had no effect on arterial oxygen tension (PaO2) and PaCO2 in any of the groups. Therefore, despite similar effects on ventilation, the improvement of arterial PO2 by almitrine depends on the underlying disease.

Administration, Oral↗
PubMed1986

[Comparison of the bronchodilator and protective effect of methylxanthines].

UNLABELLED: In study I, carried out on 9 asthmatics to investigate whether the bronchodilator and protective effect of intravenous theophylline, dissolved in ethylene diamine (T.E.) or proxyphylline and diprophylline (T.P.D.), showed different dose-effect relationships, 100 mg theophylline with T.E., T.P.D. or NaCl (placebo) were infused 5 times at 30 minute intervals. This was followed by inhalation of 0.4 mg fenoterol. Results showed that the bronchodilator effect of 500 mg theophylline with a serum concentration greater than 15 mg/l was only about 60% of that for fenoterol alone. In study II, 11 patients with exercise-induceable respiratory obstruction received 200 and 351 mg theophylline with T.E., 200 mg with T.P.D. or placebo prior to exercise and cold air inhalation. Here theophylline had a dose-dependent protective effect. With a theophylline serum concentration of 5 mg/l there was already a reduction in exercise asthma by more than 60% in comparison to placebo. At comparable serum concentrations the effect of T.P.D. was better than T.E. in both studies although the difference was not statistically significant. CONCLUSION: Since the bronchodilator effect of methylxanthines is less than the protective effect, the prophylactic use of theophylline should be given more attention.

Adolescent↗
PubMed1986

Airway response to methacholine during exercise induced refractoriness in asthma.

To investigate the mechanisms contributing to refractoriness in exercise induced asthma a methacholine challenge test was performed 30 minutes before and 30 minutes after two exercise tests 45 minutes apart. Exercise was performed by 12 asthmatic patients while they were breathing cold air. There was a smaller airway response to the second exercise test than to the first, though there was wide variation between subjects. The response to the second methacholine challenge was reduced in some patients but showed no significant change overall. Refractoriness to exercise induced asthma positively correlated with a reduced response to methacholine. These data suggest that mediator depletion does not fully explain refractoriness.

Adolescent↗
PubMed1986

Bronchodilator effect of theophylline preparations and aerosol fenoterol in stable asthma.

To compare the acute bronchodilator effect of increasing doses of intravenous theophylline and inhaled beta adrenergic agonists, we administered intravenous theophylline dissolved in ethylenediamine or proxyphylline and diprophylline or placebo in a double blind fashion to nine asthmatics on three different days. At each session, 100 mg theophylline or placebo were given during each of five subsequent periods of 30 minutes' duration and followed by inhalation of 0.4 mg fenoterol. In contrast to placebo, 500 mg theophylline in ethylenediamine or proxyphylline and diprophylline significantly decreased mean specific airway resistance (SRaw in cmH2O.s) from 31.2 to 23.6 or 34.2 to 23.5 at theophylline serum concentrations of 14.4 or 16.6 mg/L, respectively. Fenoterol lowered SRaw to about 40 percent of the respective baseline values independent of theophylline or placebo pretreatment. We conclude that the acute bronchodilator effect of theophylline is weak in comparison to inhaled beta agonists. Furthermore, proxyphylline and diprophylline cause a weak but not significant bronchodilation when compared to ethylenediamine.

Airway Resistance↗