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Biomedical subjects

H Magnussen

Publications and source records attributed to H Magnussen.

At least 253 records · Page 14Linked to original sources
PubMed1990

[Effect of nitrogen dioxide on exercise-induced bronchial asthma and the sensitivity of the respiratory tract to methacholine].

In patients with bronchial asthma, airway hyperreactivity may be further increased by exposure to low concentrations of nitrogen dioxide. We studied the effect of inhaled nitrogen dioxide in 11 patients with bronchial asthma who presented with normal lung function values. On two different days, 20 min tidal breathing of either filtered air or 0.25 ppm nitrogen dioxide was followed by bicycle exercise (average minute ventilation 30 l/min). One hour after the end of exercise, we performed a methacholine provocation challenge and determined PC100SRaw. The methacholine provocation challenge was repeated on another day (control day). Mean (SEM) SRaw increased by 79.8 (23.8) % and 82.4 (24.9) % after breathing of filtered air and nitrogen dioxide during exercise, respectively (n.s.). Mean (SEM) PC100SRaw was 0.409 (0.205), 0.407 (0.201) and 0.455 (0.181) mg/ml after breathing of filtered air, nitrogen dioxide and on the control day, respectively (n.s.). We conclude that in mild asthmatics short-term exposure to 0.25 ppm nitrogen dioxide does not enhance airway responsiveness to exercise or methacholine.

Adult↗
PubMed1990

[General environmental pollutants: effect on at-risk groups].

A number of epidemiologic studies have emphasized the relationship between air pollution and the frequency of respiratory symptoms in patients with underlying airway diseases. On the basis of acute controlled exposure studies, SO2 causes transient airflow obstruction in patients with asthma, but not necessarily in patients with bronchitis or lung fibrosis. The photochemical oxidants (ozone, NO2) induce an increase in airway responsiveness, ozone being of greater potential hazard than NO2. These effects have been described for healthy subjects and asthmatics. Acid aerosols may produce transient bronchoconstriction in asthmatics. In general, the harmful effects of polluted air will first affect the most sensitive persons in the population, such as asthmatics.

Air Pollutants↗
PubMed1990

Airways response of asthmatics after a 30 min exposure, at resting ventilation, to 0.25 ppm NO2 or 0.5 ppm SO2.

We compared the effect of inhaled NO2 and SO2 on airway tone and airway responsiveness in 14 nonsmoking mild asthmatics (mean +/- SD age 34 +/- 14 yrs; mean +/- SD baseline forced expiratory volume in one second (FEV1), 86 +/- 17% pred). On 3 separate days, 30 min tidal breathing (average minute ventilation 10.6 l.min-1) of either filtered air, 0.25 ppm NO2, or 0.5 ppm SO2 was followed by an isocapnic hyperventilation test with 0.75 ppm SO2. To determine the provocative ventilation necessary to increase specific airway resistance (sRaw) by 100% (PV100sRaw) ventilation was increased in steps of 15 l.min-1, each step lasting 3 min. Resting ventilation of filtered air, NO2, or SO2 was followed by a slight but significant overall decrease of sRaw from 8.8 to 7.7 cmH20.s-1, with no differences between the study days. Mean +/- SEM PV100sRaw(SO2) was 46.5 +/- 5.1, 37.7 +/- 3.5 and 45.4 +/- 4.2 l.min-1 after tidal breathing of filtered air, NO2, and SO2, respectively. PV100sRaw(SO2) was significantly lower after NO2 as compared to filtered air or SO2 (p less than 0.01). There was a significant correlation (rs = 0.86) between the individual shift of PV100sRaw(SO2) after NO2 and the shift after SO2 as compared to filtered air. From these individual comparisons we suggest that in asthmatics short-term exposure to NO2 at rest enhances airway responsiveness to hyperventilation of SO2 without altering airway tone, whereas short-term exposure with low concentrations of SO2 does not.

Adult↗
PubMed1990

[High-dose inhaled beta-2 sympathomimetics in severe bronchial asthma].

We made the observations that in patients with severe bronchial asthma, the inhalative dose of beta-2 sympathomimetics that was required for optimal bronchial dilation revealed a large inter-individual scatter. In 21 patients, the inhalation of a maximum of 10 metered doses of salbutamol at intervals of five minutes each, led to a mean (SD) increase in the FEV 1.0 from 1.3 (0.6) 1 to 1.8 (0.7) 1. The maximum increase in the FEV 1.0 was achieved in 10 patients following the inhalation of 1 to 3 metered doses, and in 11 patients after 4 to 10 such doses. The individual requirement for inhaleable beta-2 agonists should therefore be taken into account when planning treatment.

Administration, Inhalation↗
PubMed1990

[Pulmonary risks caused by exposure to glass fiber dust].

We observed two patients who, after inhaling glass fibre dust for 14 and 16 years, respectively, developed a cough and dyspnoea on exertion. Our investigation of transbronchially obtained lung tissue with the aid of light microscopy, electron microscopy and energy-dispersive x-ray micro-analysis revealed fibrosis of mild extension in immediate topographical relationship to phagocytosed fragments of glass fibre. We conclude from these findings that inhaled glass fibre dust can develop a fibrogenic effect.

Biopsy↗
PubMed1990

[The effect of quiet breathing of nitrogen dioxide and sulfur dioxide on the sensitivity of the respiratory tract to hyperventilation of sulfur dioxide].

In 14 patients with an oversensitive bronchial system (non-smokers), we investigated the question as to whether quiet breathing in a nitrogen dioxide or sulphur dioxide atmosphere would modify the sensitivity of the airways to sulphur dioxide. On three consecutive days, over a period of 30 minutes at rest, the patients breathed either filtered air or an atmosphere containing 0.25 ppm nitrogen dioxide, or 0.5 ppm sulphur dioxide. There then followed isocapnic hyperventilation of 0.75 ppm sulphur dioxide in increasing ventilation steps of 3 minutes duration each. On three other experimental days, in 7 patients, a stepwise hyperventilation of filtered air was carried out. Quiet breathing of nitrogen dioxide or sulphur dioxide resulted in no obstruction of the airways. The ventilation required to achieve a doubling of the specific airway resistance (PV100SRaw) during hyperventilation of sulphur dioxide was, on average, 46.5, 37.7 and 45.4 l/min after inhalation of filtered air, nitrogen dioxide and sulphur dioxide, respectively. Following nitrogen dioxide, PV100SRaw was significantly smaller (p less than 0.01 than following filtered air or sulphur dioxide. During hyperventilation of filtered air, the average PV100SRaw was 58.2, 51.8 and 55.7 l/min, respectively. We conclude that in non-smokers with an hypersensitive bronchial system, the inhalation of nitrogen dioxide can bring about an increase in the obstructive reaction to sulphur dioxide, without itself leading to an obstruction of the airways; in contrast, sulphur dioxide does not modify the degree of sensitivity.

Adult↗
PubMed1990

[Recurrence of lung tuberculosis: causes and sequelae].

Despite the fact that anti-tuberculous chemotherapy is highly effective, recurrent disease is occasionally observed. In 25 patients, we investigated the reasons for this. In 21 of these cases, the last chemotherapeutic treatment had not been carried out in a proper manner. In 13 cases patient compliance had been inadequate, in 7 cases the instructions given by the physician were unsatisfactory. We conclude from our results that the success of tuberculosis treatment can be improved by better management of the patient, and by improving the doctor's training.

Adolescent↗
PubMed1990

[Patients with sarcoidosis frequently have bronchial hyperreactivity].

Histamine provocation challenges were performed in 60 patients with pulmonary sarcoidosis. Bronchial hyperreactivity was present in 14 (23%) of them, have an increased prevalence of 8 (13%) patients with hyperreactive airways had an additional history of bronchial asthma. Our findings thus suggest an increased prevalence of bronchial hyperreactivity in patients with sarcoidosis, which may be due to bronchial asthma in some of them.

Adult↗
PubMed1989

Duration of the effect of a single dose of azelastine on histamine-induced bronchoconstriction.

We studied the duration of the protective effect of azelastine against histamine-induced bronchoconstriction in six subjects with asymptomatic asthma. The study was performed in two periods of five consecutive days each. After a histamine inhalation test, we randomly administered either placebo or a single oral dose of 8.8 mg azelastine in a double-blind crossover fashion. Histamine challenges were repeated 5 hours after ingestion and at 1 PM on the following four days. The geometric means of the dose of histamine (in cumulative breath units [cbu]) necessary to increase specific airway resistance by 100% as compared with baseline (PD100SRaw) were 8.7 and 8.5 cbu before placebo and azelastine, respectively. Placebo did not significantly influence PD100SRaw within 99 hours after treatment. Five and 27 hours after azelastine, PD100SRaw increased to 178.2 and 46.7 cbu, respectively (p less than 0.05). Two patients showed a highly significant protection against the airway effect of histamine even 99 hours after ingestion (p less than 0.01). These data demonstrate a variable duration of the antihistaminic property of azelastine. The prolonged therapeutic effect in some patients may be beneficial in the timing of medication intervals.

Administration, Oral↗
PubMed1989

Roles of hyperresponsiveness and airway inflammation in bronchial asthma.

Bronchial hyperresponsiveness is one important feature of bronchial asthma, and evidence has been accumulated that airway inflammation contributes to the specific airway response in asthmatic patients. Increase in airway responsiveness following viral infection, exposure to allergen, ozone or chemical sensitizers supports the evidence for a link between hyperresponsiveness and airway inflammation. However, as only some respiratory tract infections induce an increase in hyperresponsiveness, and patients with chronic bronchitis and cystic fibrosis have less airway hyperresponsiveness than asthmatics, airway inflammation is considered to be only one of many factors contributing to the hyperresponsiveness of asthmatic airways.

Allergens↗
PubMed1989

Airway responsiveness to methacholine does not change during chemotherapy in patients with chronic bronchitis and bronchial carcinoma.

To investigate the role of leukocytes and neutrophils in the peripheral blood on airway responsiveness, we studied nine patients with chronic bronchitis and histologically proved bronchial carcinoma before and after chemotherapy. The concentration of methacholine (in mg/ml) necessary to increase specific airway resistance by 100%, PC100SRaw, and the number of leukocytes and neutrophils (in cells x 10(6)/ml) were measured before, and 8 and 16 days after chemotherapy. Mean (SEM) total number of leukocytes decreased significantly (p less than 0.001) from 9.0 (0.8) to 4.4 (0.6) and 3.4 (0.4), and mean (SEM) number of neutrophils decreased significantly (p less than 0.005) from 5.1 (0.7) to 2.8 (0.5) and 1.0 (0.4), respectively. Mean (SEM) PC100SRaw was 3.3 (0.9) at baseline and 3.5 (1.2) and 3.8 (1.0) mg/ml at Days 8 and 16, respectively, without significant differences. These data suggest that a significant chemotherapy-induced leukocyte depletion in the peripheral blood does not influence airway responsiveness in patients with chronic bronchitis and bronchial carcinoma.

Bronchial Neoplasms↗
PubMed1989

[The prognosis of bronchial asthma in childhood].

The prevalence of childhood asthma is about 10% as compared to 6% in adults. 40% to 80% of asthmatic children become symptom-free during adolescence, but asymptomatic bronchial hyperreactivity may persist. About one third of those patients who have become symptom-free during adolescence will have relapses in adult life. Some factors seem to predict a worse prognosis of the disease: positive family history, concomitant allergic diseases, eczema, severe symptoms at the onset of the disease and during adolescence, a high degree of non-specific bronchial hyperreactivity, active and passive smoking. Questionable prognostic factors include sex, age of onset and breast-feeding.

Asthma↗
PubMed1988

[Computed tomography of bronchiectasis].

Twenty-six patients with suspected bronchiectasis were examined by bronchography and CT and the CT appearances of normal and abnormal bronchi are described. Like bronchography, CT will distinguish between cylindrical and cystic bronchiectasis. Lobar and segmental localisation can be reliably achieved by both methods; there was agreement between these methods in 109 out of 114 lobes and in 391 out 468 segments. In our experience the sensitivity of CT in the diagnosis of bronchiectasis is 93% and specificity is 96%. It is possible to obtain the necessary information, i.e. the existence and localisation of bronchiectasis by means of CT.

Adult↗
PubMed1988

Pulmonary metastasizing hemangiopericytoma.

Hemangiopericytomas are rare tumors, originating from pericytes of the small vessels, that can appear anywhere in the body. From the histological picture it is difficult to determine whether or not they are malignant. The metastasizing rate depends upon the tumor's location and varies from 50 to 80%. Local recurrences occur in roughly 50% of the cases. Hemangiopericytoma is normally surgically treated because radio- and chemotherapy are generally less effective. There is limited experience in treating metastasizing hemangiopericytomas with chemotherapy. We treated 2 patients with pulmonal metastasizing hemangiopericytoma: In 1, the tumor originated in the brain and in the other, the left knee. Both patients had chemotherapy over an extended period of time. By means of x-ray, histological, and electronmicroscopical examinations we report on the course of the diseases.

Adult↗
PubMed1988

The effect of azelastine on exercise-induced asthma.

In ten young asthmatic subjects, we studied the effect of a single oral dose of 4.4 mg of azelastine hydrochloride on exercise-induced bronchoconstriction during the breathing of cold air. Exercise challenges were performed on two different days before and four hours after azelastine and placebo given in a randomized double-blind crossover fashion. Placebo had no effect on baseline pulmonary function and postexertional obstruction of the airways, in contrast to azelastine, which exerted a small but significant (p less than 0.05) bronchodilation and a significant attenuation (p less than 0.01) of exercise-induced bronchoconstriction as compared to data from before treatment and after placebo.

Adult↗
PubMed1988

[Bronchial carcinoma: demands on the clinician and radiologist].

The pneumologist, radiologist and thoracic surgeon are an inseparable team in diagnosis and therapeutical planning in bronchial carcinoma. However, our main concern is to limit the number of imaging methods that are not necessary in the actual diagnosis and treatment of the disease. We should like to emphasise on the basis of our experience that the early use of bronchiological and other thoracic endoscopic methods is always justified. Hence, the pneumologist must make the following demand on the radiologist: The radiologist must invite the pneumologist for assessment and treatment already after the first suspicion of bronchial carcinoma becomes evident on x-ray film or during screening. The pneumologist will then establish the need for employing other imaging methods on the basis of the pattern of signs and symptoms presented by the patient.

Carcinoma, Bronchogenic↗