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Biomedical subjects

F Madsen

Publications and source records attributed to F Madsen.

At least 109 records · Page 6Linked to original sources
PubMed1985

Bronchial hyperreactivity to leucotriene D4 and histamine in exogenous asthma.

Reactivity of the small and large airways to inhaled leucotriene D4, one of the leucotrienes that constitute slow reacting substance of anaphylaxis, was studied in eight patients with exogenous asthma and nine healthy subjects with no history of atopy. Non-cumulative dose response relations were constructed for leucotriene D4 in a randomised, double blind set up. Reactivity to the leucotriene was compared with reactivity to histamine in the two groups. Both groups reacted to leucotriene D4 with significant airway obstruction evident in forced expiratory volume in one second (FEV1), peak expiratory flow rate, maximal expiratory flow rate at 30% of forced vital capacity estimated from a partial flow volume curve initiated at 50% of vital capacity (V30), and an increase in volume of trapped gas. The airways of the patients were significantly (p less than 0.01) more reactive to leucotriene D4 than those of the controls. The differences were in order of magnitude, 10(2)-10(3) for FEV1 but only about 15 for V30 (p less than 0.05). The hyperreactivity of the airways of the asthmatic subjects to leucotriene D4 was comparable to that to histamine. Inhalation of leucotriene D4 caused pronounced dyspnoea only among the patients. The findings suggest a role for leucotriene D4 in human bronchial asthma.

Adolescent↗
PubMed1985

Bronchial histamine challenge. A combined interrupter-dosimeter method compared with a standard method.

We compared the provocative concentration (PC) values obtained by two different methods of performing bronchial histamine challenge. One test was done on an APTA, an apparatus which allows simultaneous provocation with histamine and measurement of airway resistance (Rtot) by the interrupter method. The second test was a conventional tidal breathing method, with measurement of the FEV1. There was a high correlation between the PC20-FEV1 and the PC30-, PC40- and PC50-Rtot values. The correlation coefficients were 0.85, 0.71 and 0.70 (P less than 0.05) respectively. We further tested the reproducibility of the histamine challenge done on the APTA. When the PC30-Rtot values were compared, a correlation coefficient of 0.56 (NS) was found. For the PC40- and PC50-Rtot values the correlation coefficients were 0.65 (P less than 0.05) and 0.70 (P less than 0.02) respectively. We conclude that the APTA is useful for routine bronchial histamine challenge when 40-50% increase in basal Rtot is used as endpoint.

Adolescent↗
PubMed1985

Protective effect of a new anti-asthmatic agent (Minocromil) in bronchial allergen challenge tests.

Ten patients were included in a double-blind crossover trial, designed to compare the effects of a new anti-asthmatic agent Minocromil, an organic decarboxylic acid, and placebo on bronchial allergen challenge. The challenges were performed at weekly intervals. Significant differences in favour of Minocromil were found in the concentration of antigen reached at which FEV1 fell below 20% of baseline. This was confirmed by analysis of the decrease in FEV1 recorded at the highest concentrations of antigens, which showed statistically significant differences in favour of Minocromil.

Asthma↗
PubMed1985

The predictive value of bronchial histamine challenge in the diagnosis of bronchial asthma.

A prospective survey aiming to study the predictive value of bronchial histamine challenge was performed on 151 patients with a forced expiratory volume1 (FEV1) above 60% of predicted. According to variations in peak expiratory flow rate (PEFR) and medical history the patients were classified as asthmatics (n = 97) or non-asthmatics (n = 54). The diagnostic properties of the challenge were calculated using the statement of Baye. Considering PC20 values below 4.00 mg/ml as positive, the predictive value of a positive test was about 0.80 and the predictive value of a negative about 0.76. When PC20 was below 0.125 mg/ml the predictive value of a positive test was 1.00, but an increase in PC20 in the range from 4.00 to 16 mg/ml did not increase the predictive value of a negative test. In this study the prevalence of asthma was about 0.6. We therefore conclude that bronchial histamine challenge is a valuable test for detection and exclusion of bronchial asthma, when the prevalence of the disease is high. In populations with a lower frequency of bronchial asthma the diagnostic value of a positive bronchial challenge will be negligible.

Adolescent↗
PubMed1985

Inspiratory resistance versus general physical training in patients with chronic obstructive pulmonary disease.

The effect of inspiratory muscle training (IMT) three times daily for 6 weeks was compared with that of general physical training (PT) (stair climbing) in 10 out-patients with severe chronic obstructive pulmonary disease (COPD). PT improved 12 min walking distance (12MWD) by 19% (1-28), stair climbing ability (SCA) over four floors at maximum speed by 11% (3-50), maximum oxygen uptake by 10% (2-33), inspiratory flow by 85% (19-113) and improved an index of breathlessness by 44% (3-786). During IMT, 12MWD and SCA decreased by 8% (0-33) and 10% (0-161), respectively, and the other variables decreased by 6-10%. No changes were seen in ventilation during maximum exercise, in maximum inspiratory and expiratory pressures, or in variables measured during spirometry. Thus work capacity can be improved by training in COPD maybe because of an increase in inspiratory flow rate, but without a change in maximum exercise ventilation.

Aged↗
PubMed1985

Short and long term reproducibility of responsiveness to inhaled histamine: Rt compared to FEV1 as measurement of response to challenge.

Repeatability (123 min) and reproducibility (65 days) of response to inhaled histamine were tested in a selected group of stable asthmatics and non-asthmatics by means of FEV1 and breathing resistance (Rt) determined by the interruptor method. Variation in prechallenge FEV1 and Rt was kept within a +/- 10% and +/- 40% range, respectively. We found the PC20-FEV1 highly repeatable after 123 min. The 95% confidence interval for a single determination was the measured value +/- 1.72 two-fold concentration differences. Reproducibility was significantly lower (p less than 0.05). Both repeatability and reproducibility of PC30-Rt were significantly lower than that of PC20-FEV1. Interruptor method determined PC30-Rt was found repeatable within 4 two-fold concentration differences which is not acceptable for clinical and research purposes. The poor repeatability of PC30-Rt could be due to changes in functional residual capacity during challenge.

Adolescent↗
PubMed1984

The possible role of LTD4 in asthma in humans investigated in vivo.

The bronchoconstrictor effect of LTD4 was tested in a double blind design in 9 healthy volunteers who inhaled 10 and 40 nmol synthetic LTD4, 10 and 100 mumol histamine, and placebo on 5 different days. As the nebulized testsolutions were administered via a settling bag, an even deposition on the airways could be expected, and consequently a relative predominans of the changes measuring the airflow in the small airways. Accordingly the PEF values were reduced by less than 5% for both active substances. The function of the small airways was measured by (1) the volume of trapped gas in percentage of the total lung capacity, and (2) maximal expiratory flow rate at 30% of vital capacity above residual volume, determined from partial flow-volume curves. A dose-dependent bronchial obstruction was revealed. LTD4 was 3 to 4 decades more potent than histamine on a log molar scale. Pronounced dyspnoea and systemic side effects were experienced after inhalation of histamine whereas LTD4 did not cause any symptoms. Adrenergic beta 2-agonist (Fenoterol) was in all cases capable of reversing the LTD4 induced bronchospasm. 6 patients with verified exogenous asthma were tested in a similar double blind set-up for their reactivity to LTD4. The asthmatics were hyperreactive to LTD4.

Adolescent↗
PubMed1984

Compression bandage in the treatment of ankle sprains. A comparative prospective study.

The value of a compression bandage applied for 4 days following ankle sprains was assessed in a comparative study. The effect of the treatment was evaluated by changes in an inflammatory score based on a combination of subjective (pain, function) and objective (swelling, limitation of movement, pain on passive movement) factors. The study included two consecutive series each of 50 patients treated with a compression bandage, and untreated. There was no significant difference in the reduction of the inflammatory score from start to the fourth day (0.5 less than p less than 0.6) or from start to the eighth day (0.1 less than p less than 0.2) between the group treated with compression bandage and the untreated group. Analysis of the individual factors included in the inflammatory score demonstrated no difference in the course of pain, function, swelling, or limitation of movement between the two groups.

Adolescent↗
PubMed1983

Thoracoscopy: influence of the procedure on some respiratory and cardiac values.

In eight patients with pleural effusion arterial oxygen and carbon dioxide tensions (PaO2 and PaCO2), pH, respiratory frequency, and cardiac rhythm and frequency were measured before, during, and after thoracoscopy. Four of the patients had a PaO2 below 70 mm Hg (9.3 kPa) before the procedure. During and after the procedure respiratory frequency increased and PaCO2 fell, indicating hyperventilation, while the other indices remained unchanged. It is concluded that respiration and the circulation readily adapt to the changes produced by the pneumothorax and the manipulation during thoracoscopy.

Adult↗