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Biomedical subjects

A Dirksen

Publications and source records attributed to A Dirksen.

At least 91 records · Page 5Linked to original sources
PubMed1992

Atopy and bronchial responsiveness in random population sample of 527 children and adolescents.

The relationship between bronchial responsiveness, lung function, and results of skin prick testing was studied in 527 children and adolescents from Copenhagen. All participants completed a questionnaire concerning allergic symptoms (asthma, rhinitis, atopic dermatitis, and urticaria). Furthermore, skin prick test reactivity to nine common aeroallergens, lung function, serum IgE and bronchial responsiveness to histamine and exercise were measured. A total of 53 subjects were atopic, (skin prick 3+), 105 subjects had moderate skin reactivity (1-2+), and 366 subjects had no signs of atopic disease (prick test negative); 58% of the subjects with skin test reactivity (1-3+) were asymptomatic. Increasing degree of atopy was correlated significantly with symptoms such as asthma, rhinitis, dermatitis, and urticaria (P less than .001); increasing level of IgE (P less than .001); month of birth (P = .001); and family history of allergic diseases (P less than .05). The most important markers for the degree of bronchial responsiveness to inhaled histamine were the presence of respiratory symptoms (P less than .001), the degree of atopy (P = .001), a history of asthma in at least two first degree relatives (P less than .01), and the skin reactivity to house dust mites (P = .001), horse epithelium (P = .01), Alternaria iridis, and dog epithelium (P less than .05). In contrast, the degree of bronchial responsiveness to exercise was significantly correlated with asthma (P less than .001), the level of IgE (P less than .05), month of birth (P less than .001), and birth weight (P less than .05).(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1991

[Assessment of the surgical risk. Is the time between myocardial infarction and a possible surgical procedure of significance for a surgical risk?].

During a five year period, 320 patients suffered from acute myocardial infarction (AMI) and within the next twelve months became candidates for surgery for either appendicitis (99 patients) or for a hip fracture (221 patients). An evaluation of the mortality at the second event (i.e. appendicitis or hip fracture) in relation to the time between AMI and second event, was done following the intention to treat principle. Appendicitis occurred with the same incidence during all 12 months following AMI. The second event mortality was independent of the time interval from AMI to second event. Age, infarction prior to index infarction and congestive heart failure were prognostically important in relation to second event mortality, but did not affect the constant second event mortality during the first year following AMI. Hip fracture occurred more often during the first months following AMI, where the second event mortality was highest. Congestive heart failure either prior to index infarction or at the index infarction was prognostically important in relation to second event mortality. The relatively high mortality in the first months after AMI could partly be explained by an association between congestive heart failure and hip fracture in the first months after AMI. We conclude that the "operative" mortality in patients with recent AMI is high. The mortality is related to congestive heart failure and not to the time between AMI and surgery.

Appendectomy↗
PubMed1991

Spontaneous changes in bronchial responsiveness in children and adolescents: an 18-month follow-up.

The purpose of this study was to investigate spontaneous changes in bronchial responsiveness to inhaled histamine over a period of 18 months. The first measurements in 495 subjects, 7 to 16 years of age, were made in 1986. Bronchial hyperresponsiveness (BHR), i.e., PC-20 FEV1 less than or equal to 8.0 mg/mL, was found in 79 (16%) individuals, of whom 28 (35%) had symptoms of asthma. Twenty asthmatic and 42 non-asthmatic subjects who had BHR (78%) were re-examined 18 months later. The asthmatics had a modest change in BHR, while in the non-asthmatics bronchial response to inhaled histamine and exercise was significantly decreased. In twenty-two subjects (36%) bronchial response was within the normal range; of these 18 were non-asthmatic. Six asthmatics (30%) and two non-asthmatics (5%) had an increased BHR at follow-up. Two subjects (5%) developed symptoms of asthma by the time of follow-up, with an unchanged degree of BHR. Sex, age, atopic symptoms, and viral respiratory infections at the first examination were unrelated to changes in bronchial responsiveness. However, changes of BHR in the non-asthmatic subjects were significantly correlated to changes in bronchial response to exercise. Although spontaneous changes in bronchial responsiveness occur in asthmatic, as well as non-asthmatic subjects, asthmatics persistently have hyperresponsive airways. Development of asthma was found to occur among subjects with persistent BHR.

Adolescent↗
PubMed1991

The distribution of bronchial responsiveness to histamine and exercise in 527 children and adolescents.

The aim of the study was to describe the bronchial responsiveness to inhaled histamine and exercise in a randomly selected group of 527 children and adolescents from Copenhagen, aged between 7 to 16 years. The distribution of the bronchial responsiveness was described as (1) the provoking concentration that causes a 20% reduction in FEV1 (2) the dose-response slope (DRS), that is, the linear slope of the dose-response curve, and (3) reduction in FEV1 after 6 minutes of exercise on a treadmill. The distribution of the concentration that causes a 20% reduction in FEV1 in the responsive range was not significantly different from a unimodal distribution, although the findings were skewed toward the less responsive end of the range (p greater than 0.05). The subjects with asthma represented a subgroup within the responsive distribution tail rather than a separate distribution peak. In asymptomatic individuals, the values of DRS were distributed symmetrically on a logarithmic scale. The deviation from normal was such that the standard deviation only slightly underestimated the "normal" range. The distribution of the bronchial response to exercise was found to be significantly different from a normal distribution. However, a significant relationship was found between the bronchial response to inhaled histamine and exercise (p less than 0.0001). We conclude that there is a log-normal distribution of the bronchial response to inhaled histamine in a random sample of children and adolescents.

Adolescent↗
PubMed1991

Single-dose inhaled budesonide in subjects with chronic asthma.

In 30 stable asthmatics, a comparison was made between the changes in pulmonary function (FEV1, FVC, PEF, MEF75, MEF50 and MEF25) hourly for 9 h after a single dose of inhaled budesonide 1,600 micrograms, and placebo. All subjects used inhaled steroids daily; this medication was, however, withheld 8 days prior to the study. For all parameters of pulmonary function, a significant difference in favour of budesonide was demonstrated. The effect tended to decrease after 9 h, and had abated within 24 h. FEV1 age, sex, smoking habits, or results of an inhaled beta 2-agonist reversibility test could not be demonstrated as predictors of those subjects to react with the most pronounced responses to budesonide. In conclusion, our results demonstrate an effect 3 h after administration of an inhaled glucocorticosteroid in adult outpatients with chronic asthma. These results parallel previous findings in highly selected asthmatics and after systemic administration of glucocorticosteroids. Single-dose administration and subsequent monitoring for 8-9 h may therefore prove valuable in evaluating new prophylactic agents for the treatment of asthma.

Administration, Inhalation↗
PubMed1991

Sensitivity and specificity of the histamine challenge test for the diagnosis of asthma in an unselected sample of children and adolescents.

The purpose of this investigation was to study factors of importance for the degree of bronchial responsiveness and, furthermore, to evaluate the sensitivity, specificity and predictive value of a bronchial challenge test with histamine for the diagnosis of asthma in 495 randomly selected children and adolescents, aged 7-16 yrs, from Copenhagen, Rigshospitalet. Detailed history about allergic symptoms, physical examination and bronchial histamine challenge tests were performed at the out-patient clinic. Asthma, atopic disease and height were found to be of great importance for the degree of bronchial responsiveness, whereas the age, sex and smoking habits were of no significance. The percentage of asthmatics with bronchial hyperresponsiveness, i.e. sensitivity to the test, increased towards 100% on inhaling increasing concentrations of histamine, but this was accompanied by a decrease in specificity and predictive values of positive test in regard to the diagnosis of asthma. However, lower concentrations of histamine may be preferable in order to distinguish between asthma and non-asthma in population samples, as inhalation of 2.4 mg.ml-1 and provocative concentration producing a 20% fall in forced expiratory volume in one second (FEV1) (PC20) provided an acceptable sensitivity (57%), specificity (98%), and predictive value of a positive test (60%). We conclude that as regards the diagnosis of asthma, a low predictive value confirms that the bronchial challenge test plays only a supplementary, but valuable, role in detecting the disease in population samples.

Adolescent↗
PubMed1991

Bronchodilator and corticosteroid reversibility in ambulatory patients with airways obstruction.

With the aim of characterising subgroups, we analysed reversibility tests from 1,048 patients with airways obstruction (baseline FEV1 less than 60% of predicted normal (%pred), and FEV1 to FVC ratio less than 0.6). Spirometry before and after inhalation of salbutamol 0.3 mg and ipratropium bromide 0.06 mg was performed before and after one week of treatment with prednisone 30 mg daily. The changes in FEV1 after bronchodilators showed unimodal distribution (mean = 7.0 %pred, st.dev. = 6.6 %pred). The responses to corticosteroid were more spread out (mean = 6.3 %pred, st.dev. = 13.8 %pred). The correlation between bronchodilator responses before and after corticosteroid treatment was poor (r = 0.30), although highly significant (p less than 0.000,001). The responses to bronchodilators were virtually independent of the steroid reversibility. The corticosteroid response was inversely related to age (r = -0.20, p less than 0.000,001) and smoking habits (r = -0.17, p less than 0.000,001), and moderately associated with blood eosinophilia (r = 0.34, p less than 0.000,001). The frequency distribution of the bronchodilator responses and the steroid response and combinations of the responses were all unimodal, making any distinction between nosologic subgroups arbitrary. It is clear from the study that criteria other than just response to therapy must be employed for distinction of subgroups among patients with airways obstruction.

Adolescent↗
PubMed1990

[Medical informatics].

Medical informatics is the discipline concerned with information and information streams in health care. The development of information technology has been intensified in recent years and is now influencing the international development within the health care sectors. During the coming decade, integrated hospital networks will supple communication within and between hospitals. New productivity measures useful in administrative planning are being developed. Patient data are being digitalized and stored electronically, and interactive media are implemented in education. Primarily, however, chip-based technologies find application in the evaluation of the increasing quantity of paraclinical data. Internationally product development and research are actively underway. The EEC has established development programmes specifically stimulating these activities. Is Denmark going to take an active part in this development, formalized frames are required.

Denmark↗
PubMed1990

[New therapeutic possibilities in alpha 1-antitrypsin deficiency].

The alpha-1-antitrypsin gene is localized to chromosome 14. Numerous genetic variations may occur and some of these result in severely reduced concentration in the serum. The commonest cause of severe deficiency of alpha-1-antitrypsin is the gene-variant Z in the homozygotic form which occurs in one out of 2,000 Danes. Severe deficiency in alpha-1-antitrypsin results in liver symptoms in approximately 10% of the children. Some of these will develop cirrhosis of the liver. In adults at the ages of about 30 to 40 years, gradual development of emphysema occurs and this is earliest and most pronounced in smokers. Adults have also increased frequency of cirrhosis but this is much less pronounced than the development of emphysema. In addition to a number of theoretical therapeutic possibilities, liver transplantation is now possible and this is employed particularly in children with cirrhosis. In young persons with terminal pulmonary insufficiency with anticipated survival for less than one year, heart/lung transplantation or possibly isolated lung transplantation may be considered. An alpha-1-antitrypsin concentrate has been produced. Intravenous dosage once monthly can provide a concentration in the serum for three to four weeks which, as a rule, suffices to prevent emphysema. It is not yet known whether this treatment has any prophylactic effect in cases of developed emphysema. It is to be anticipated that treatment instituted prior to development of emphysema will prevent development of pulmonary disease but the treatment is rather expensive and must, probably, continue throughout life. No controlled investigation of the effect of treatment is available and the range of indications is not defined.

Female↗
PubMed1990

[Pulmonary function and survival of patients with alpha 1-antitrypsin deficiency, residents of Copenhagen].

From 1976 to 1987 alpha 1-antitrypsine deficiency type PiZZ was diagnosed in 89 patients living in the Copenhagen urban area (mean age: 45 years). Spirometry was performed yearly in 66 of these patients (mean observation period was 50 months). At the time of diagnosis basic FEV1 was significantly lower in smokers and ex-smokers than in patients who had never smoked (45%, 44% and 84% of predicted normal, respectively). However, the decline in FEV1 was similar (3% per year) in all three categories of smokers. Our results indicate that both smokers and non-smokers are at risk of developing pulmonary emphysema, however, the disease usually appears later in life or not at all in non smokers.

Adult↗
PubMed1990

Decline in pulmonary function in patients with alpha 1-antitrypsin deficiency.

Sixty-five patients with severe alpha 1-antitrypsin (AAT) deficiency (phenotype PiZ) were followed with spirometry at regular intervals of one year and a median observation period of four years. The annual decline in pulmonary function was adjusted for sex, age and height by division with the predicted normal pulmonary function. The median decline in FEV1 was 1.9% predicted/year. The rate of decline was independent of age and pulmonary function, except for patients with FEV1 below 25% of predicted normal. There was a tendency towards a slower median decline in FEV1 in ex-smokers (1.7% predicted/year) compared to smokers (3.8% predicted/year) and never-smokers (3.7% predicted/year), however, this difference was not significant (p greater than 0.01). At the time of diagnosis smokers and ex-smokers had a lower FEV1 (44 and 38% predicted) than never-smokers (85% predicted) (p less than 0.02), and smokers and ex-smokers were generally younger (median age 44 and 42 years, respectively) than never smokers (median age 55 years) (p greater than 0.1). Our data indicate that smokers as well as nonsmokers with severe AAT deficiency are at risk of developing pulmonary emphysema. The disease seems to appear later in nonsmokers, though once initiated it progresses at the same rate.

Adult↗
PubMed1990

Hyposensitization in asthmatics with mPEG-modified and unmodified house dust mite extract. IV. Occurrence and prediction of side effects.

A double-blind study on hyposensitization (HS) with two extracts prepared from the house dust mite Dermatophagoides pteronyssinus (Dp) was performed on a group of asthmatics with bronchial sensitivity to Dp. In 18 patients, aluminium-hydroxide was added to the Dp-extract to give a depot effect (Dp-group). Nineteen patients were treated with a similar extract in which allergenicity had been reduced by coupling to monomethoxypolyethylene glycol (mPEG-Dp-group). This extract had previously been shown to have less effect on clinical symptoms and skin sensitivity compared to the Dp-extract. In the Dp- and mPEG-Dp-groups, 778 and 675 injections were administered. Fifteen and 12 patients in the Dp- and mPEG-Dp-groups had systemic reactions (P greater than 0.05). The frequency of injections giving systemic reactions was reduced in the mPEG-Dp-group: 5.1% compared to 9.0% in the Dp-group (P less than 0.01). In the mPEG-Dp-group, reactions were mild to moderate, mainly late-occurring asthma and urticaria, whereas two episodes of anaphylaxis and four of severe asthma occurred in the Dp-group. The reduction in side effects seems promising, but a further dose increase in the mPEG-Dp-group would be necessary to compare the side effects of doses with equal therapeutic effectiveness. High frequency of late local reactions made dose increase impossible with the present slightly modified extract. The systemic side effects occurred more frequently in patients highly skin test-sensitive to Dp prior to treatment. All patients skin test-positive to less than or equal to 100 BU had systemic reactions. Systemic side effects could not be predicted from the size of previous local reactions.

Animals↗
PubMed1990

Methylprednisolone pulse therapy in acute severe asthma. A randomized, double-blind study.

Methylprednisolone pulse therapy (MPPT) has been shown to possess a long-lasting effect in other immune-inflammatory diseases without the well-known side effects caused by long-term treatment with glucocorticosteroids. In an attempt to reduce the long-term use of oral steroids in asthmatics, we conducted this double-blind, double-dummy study to compare the use of MPPT (1 g of methylprednisolone intravenously) (8 patients) with a short course of oral prednisolone (10 patients) in asthmatics presenting with acute severe asthma. Both treatments were effective in relieving the acute attack of asthma. The MPPT-treated patients did not show a faster resolution than did the orally treated group. No patients needed assisted ventilation, and no deaths occurred. One week after the treatment FEV1 tended to decrease in the methylprednisolone group compared with the oral prednisolone group (P = 0.06). The patients initially receiving MPPT needed supplementary prednisolone earlier and in higher doses than did the patients receiving oral prednisolone as initial treatment. At the end of the 12 weeks' study period, the groups reached identical FEV1. In conclusion, we did not find intravenous methylprednisolone superior to oral prednisolone in the treatment of acute attacks of severe asthma, but methylprednisolone pulse therapy had a shorter duration as regards protection against future asthma attacks.

Acute Disease↗
PubMed1989

Monitoring kidney function in diabetic nephropathy.

We investigated the validity of a one plasma sample method (I) compared with a multiple plasma sample method (II) for routine clinical determination of glomerular filtration rate (GFR) in 35 insulin-dependent diabetic patients suffering from nephropathy. GFR was measured after an intravenous bolus injection of 100 microCi 51Cr-EDTA by determination of plasma radioactivity in venous blood samples taken from the other arm 180, 200, 220 and 240 min after the injection (II). The plasma radioactivity in the sample drawn 240 min after injection was used in method I. During the mean investigation period of 32 months (12-62 months) a total of 184 GFR determinations were performed. The average interval between the GFR measurements was 6 months (1-21 months). In 127/184 of the study intervals method I indicated a decrease in GFR. The corresponding figure for method II was almost identical, 130/184. The mean decline in GFR was 8.1 +/- 7.2 and 7.8 +/- 6.9 ml year-1 1.73 m-2 using methods I and II, respectively (NS). The methods essentially provided the same GFR values in absolute terms (r = 0.98, P less than 0.001). We conclude that the one plasma sample method can be used as a valid routine technique in non-uraemic patients with nephropathy.

Adult↗
PubMed1989

Prevalence and predictors of bronchial hyperresponsiveness in children aged 7-16 years.

To study the prevalence and possible predictors of bronchial responsiveness we examined a cross-section of 527 children aged 7-16 years from Copenhagen. The method used included an interview with the child and the parents, skin prick test with common allergens and se-IgE. Bronchial responsiveness was measured by a histamine inhalation test. We found that 79 (16%) of the children had bronchial hyperresponsiveness (BH), defined as a 20% fall in FEV1 with a provoking concentration of histamine (PC20) at 8 mg/ml or less. Atopic symptoms defined as asthma, rhinitis or eczema were significantly (P less than 0.001) correlated to BH both in prevalence and degree of BH. None of the children with urticaria had BH. The degree of bronchial responsiveness was also significantly influenced (P less than 0.001) by family disposition to atopy, whereas we found no correlation between BH and "passive" smoking, specific skin test in unselected children, or elevation of IgE in children without atopic symptoms. We conclude that BH is severest in children with asthma, independent of elevated IgE or positive skin prick test. Children with rhinitis, dermatitis, or asymptomatic BH have the same degree of BH; this differed from that in children with asthma.

Adolescent↗
PubMed1989

Effect of a non-sedative antihistaminic (loratadine) in moderate asthma. A double-blind controlled clinical crossover-trial.

Seventeen patients with perennial asthma, stable on a moderate dose of inhaled steroid, participated in a crossover study comparing the clinical effect of a non-sedative, potent and highly selective H1 antagonist (loratadine 10 mg) with placebo. Each treatment period began with 2 weeks run-in followed by 8 weeks on either antihistamine or placebo. During the 8-week periods inhaled steroid was gradually tapered according to a fixed scheme. One patient was withdrawn from active treatment and three from placebo periods because of decreasing lung function (P greater than 0.1). Among the remaining 13 patients there was a threefold (1.8-4.8) decrease in the bronchial sensitivity to histamine during treatment with antihistamine compared to placebo (P less than 0.01). There was a trend in favour of active treatment with regard to changes in all symptom scores, lung function and use of escape medication, but these differences were not statistically significant. The increase in FEV1 was less than 5% of predicted normal (P less than 0.05). We concluded that the bronchial response to histamine can be attenuated by loratadine, an oral H1 receptor antagonist, but further studies are necessary to assess the clinical usefulness and place of loratadine in the therapy of asthma.

Adult↗
PubMed1989

Rheumatoid arthritis cells and biochemical changes in turpentine-induced pleuritis in rabbits.

When turpentine was instilled into the right pleural cavity in rabbits a pleural effusion developed in half of the animals, with a low pH, low glucose concentration, high lactic dehydrogenase activity and the constant presence of rheumatoid arthritis cells in the affected pleural cavity. The biochemical values in the pleural fluid were significantly different from the values for normal pleural fluid obtained by a special microtechnique. These changes resulting from the experimentally induced, simple, irritative turpentine pleuritis are similar to the findings in the pleural effusion in human rheumatoid pleuritis; this implies that such changes are probably non-specific and without evidence of an immunological background.

Animals↗