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Biomedical subjects

N Bach-Mortensen

Publications and source records attributed to N Bach-Mortensen.

At least 19 recordsLinked to original sources
PubMed1995

[Body proportions of Danish children. Curves for sitting height ratio, subischial length and arm span].

No previous Danish growth charts have been published for sitting height, subischial leg length, armspan or the ratio of sitting height to stature. These growth charts are useful in the evaluation of dysproportional growth retardation. Foreign standards have previously been used. However, due to population-specific differences and "the secular trend", the construction of Danish growth charts was found to be appropriate. We examined 1977 children (927 boys and 1050 girls) from the Copenhagen area, aged six to 20 years. Height, sitting height and armspan were measured. Growth charts were constructed using local linear regression and smoothing of residuals. We found sitting height values in Danish children to be comparable to English and Norwegian children. Sitting height values were lower than values of Dutch children, but higher than values of Swiss and Swedish children. The extremities of Danish children were 3-4 cm longer than the extremities of English children, but Dutch children had 2-3 cm longer armspan than the Danish boys and girls. Growth charts for sitting height, sitting height ratio, subischial leg length and armspan are presented. These charts should be useful when evaluating dysproportionality in growth retarded children and when assessing the effect of growth modulating therapy in children.

Adolescent↗
PubMed1994

Bronchial responsiveness in children and adolescents: a comparison between previously asthmatic, currently asthmatic, and normal subjects.

The aim of this study was to examine the degree of bronchial responsiveness in previously asthmatic subjects. Of 253 patients, born within 1964-1974, followed in the pediatric department at the University hospital in Copenhagen, 224 subjects (89%) were successfully contacted by telephone; of these 195 complained of persistent asthma and 29 (13%) had had no asthmatic symptoms for at least 2 years. On the basis of the degree of respiratory symptoms, 58 individuals were examined at the outpatient clinic. Of these, (1) 19 were previously asthmatics, (2) 20 had current mild asthma, and (3) 19 had current severe asthma. Furthermore, 19 healthy individuals, age-matched with the preceding asthmatic subjects, were selected as controls. In all subjects, skin prick tests, lung function tests, and bronchial challenge tests with inhaled histamine and bronchodilator were performed. Furthermore, the subjects measured their peak expiratory flow (PEF) twice daily during a period of 4 weeks. Of the 39 current asthmatic subjects, 82% had a PC20 < or = 8 mg/ml, whereas all previously asthmatic subjects and the controls had a PC20 > 8 mg/ml. The degree of bronchial responsiveness as indicated by the dose-response slope (DRS), the percentage change in forced expiratory volume in 1 sec (FEV1) per inhaled mumol of histamine, was found to be significantly higher in previously asthmatic patients (median logDRS 0.1 delta %FEV1/mumol) than in controls (median logDRS-0.4 delta %FEV1/mumol) (p < 0.001). Furthermore previously asthmatic subjects had significantly increased change in FEV1 after inhalation of bronchodilator and peak expiratory flow variability compared to controls. These findings suggest that apparently asymptomatic previously asthmatic subjects have increased airway variability.

Adolescent↗
PubMed1993

[Allergy and bronchial reactivity in children and adolescents from Copenhagen].

The relationship between bronchial responsiveness and the results of a skin prick test was studied in 527 children and adolescents from Copenhagen. All participants completed a questionnaire concerning birth weight, breastfeeding, month of birth, month of examination, allergic symptoms in themselves or their parents. Furthermore, skin prick test reactivity to nine common aero-allergens, lung function, serum IgE, and bronchial responsiveness to histamine and exercise were measured. A total of 158 (30%) subjects showed signs of allergy (defined as a positive reaction to the skin prick test), of whom 53 (10%) subjects had positive skin reactivity and 105 subjects had moderate skin reactivity; 366 (70%) subjects had no signs of allergic disease as measured by the pride test. The most important marker for the degree of bronchial responsiveness was asthma (p < 0.001), month of examination (p < 0.01) and allergy (skin reactivity to one or more allergens) (p < 0.05). Furthermore, the degree of bronchial responsiveness to inhaled histamine was significantly related to a history of asthma in two first degree relatives (p < 0.01) and the skin reactivity to house-dust mites (p < 0.01), whereas the degree of bronchial responsiveness to exercise was significantly associated with the level of serum IgE (p < 0.05), month of birth (p < 0.001) and birth weight (p < 0.05). In conclusion, allergy is an important risk factor for the presence of increased degree of bronchial responsiveness to inhaled histamine and to exercise.

Adolescent↗
PubMed1993

Relationship between viral antibodies and bronchial hyperresponsiveness in 495 unselected children and adolescents.

The purpose of this study was to investigate whether recent and previous subclinical viral respiratory infection can explain the presence of increased bronchial responsiveness to histamine. We studied a randomly selected population of 495 children and adolescents, aged 7-16 years, from Copenhagen. If the subjects had had symptoms of respiratory infection recently, the examination was postponed for at least 6 weeks. Bronchial hyperresponsiveness (BHR) to inhaled histamine was found in 79 (16%) of the subjects, of whom 28 had asthma. Forty-eight subjects (10%) had increased levels of serum IgM antibodies against either parainfluenza, influenza, adenovirus, or respiratory syncytial virus (RSV), reflecting a recently acquired infection. No association between BHR and antibodies against respiratory viruses was found, as 7 (8.9%) of the 79 subjects with BHR and 41 (9.9%) of the 416 subjects without BHR had viral antibodies. Furthermore, no association between degree of bronchial responsiveness and viral antibodies was found. Moreover, 251 individuals (51%) had signs of earlier RSV infection, i.e. IgG antibodies against RSV. No relationship was found between age of the subjects and the presence of antibodies against either respiratory viruses in general or IgG-RSV. No relationship was found between the presence of antibodies against RSV and BHR; furthermore, evidence of earlier RSV infection was unrelated to the level of lung function and degree of bronchial responsiveness. We conclude that increased bronchial responsiveness in asymptomatic, unselected schoolchildren and adolescents is not likely to be caused by recent or previous viral respiratory infections.

Acute Disease↗
PubMed1993

Pulmonary function in adolescents with childhood asthma.

The aim of this study was to determine the pulmonary function in former and present asthmatics. We examined 77 persons aged 12-24 years, classified into four groups: 1) healthy subjects (controls) (n = 19), 2) former asthmatics (n = 19), 3) present mild asthmatics (n = 20), and 4) present severe asthmatics (n = 19). Although exhibiting no respiratory symptoms, former asthmatics had reduced airflow values measured by FEV1 (median (range) 89.7 (83-99) vs 101.4 (91-110)) and MEF25 (76.5 (68-94) vs 103.0 (97-124)), as compared with controls. Furthermore, former asthmatics had significantly increased PEF variability, as compared with controls, whereas no significant differences were found in static lung parameters, i.e. total lung capacity and residual volume, as compared with controls. In conclusion, former asthmatics, although now exhibiting no respiratory symptoms, were found to have obstructive airflow limitation, increased bronchial responsiveness, and normal lung volumes.

Adolescent↗
PubMed1992

Distribution of serum IgE in children and adolescents aged 7 to 16 years in Copenhagen, in relation to factors of importance.

The distribution of total serum-IgE and factors of importance for the level of IgE was studied in a random sample of 508 children and adolescents, aged 7-16 years, from Copenhagen. A detailed history about asthma, rhinitis, dermatitis and urticaria was obtained, and a physical examination, skin prick test with 9 common allergens, lung function test, bronchial challenge with inhaled histamine and exercise, and measurement of IgE (kU/l) were performed. The distribution of IgE among children and adolescents was found to exhibit a log normal distribution and a positive skin prick test, allergic symptoms, a family history of allergic diseases, age and smoking were found to be significantly related to an increased level of IgE. No relationship was found between increased bronchial responsiveness and IgE. The geometric mean of "normal" values of IgE (*1 SD and *2 SD) of the Danish children and adolescents was 18 kU/l (*4.7, *18.2), suggesting that normal IgE values were within 330 kU/l. Measurement of IgE as the only screening for allergic disease is unreliable, as the predictive value of an elevated IgE in population samples was found to be 50%, whereas misclassification (1-specificity) of asymptomatic subjects as allergic because of an increased IgE was low (4%). In conclusion, total IgE is highly influenced by allergen skin reactivity. Further, this study suggests that normal IgE values were within 330 kU/l, although the range was wide.

Adolescent↗
PubMed1992

Bronchodilating effect of ipratropium bromide inhalation powder and aerosol in children and adolescents with stable bronchial asthma.

The purpose of this study was to compare the bronchodilating effect of ipratropium bromide (IB) administered by a conventional Ingelheim powder device system (IPI) and by a metered dose inhaler (MDI) in children and adolescents with stable bronchial asthma. Seventy patients, aged 7 to 16 years, with stable bronchial asthma from our outpatient clinic were tested for bronchial responsiveness to inhaled IB. Fifteen (21%) of the 70 subjects were found to have a substantial bronchial response to inhalation of 40 micrograms IB, i.e. at least 15% increase in FEV1 30 min after inhalation; the remaining 55 subjects had less than 15% increase in FEV1. No relationship between severity of asthma, age or sex and bronchial responsiveness to inhaled IB was found. Among the 15 subjects who had substantial bronchial response to IB, the increase in FEV1 after inhalation of fenoterol tended to be greater than the response to inhaled IB, although this did not reach statistical significance. Responders, i.e. subjects who had at least 15% increase in FEV1 after inhalation of IB, took part in a double-blind, cross-over study of the bronchodilating effect of 40 micrograms IB delivered by IPI and MDI. We found no significant differences in the bronchodilating effect during a 6-h follow-up. Maximum bronchodilating effect of IB was reached after 30 min and the maximum response lasted for 90 min. No side or adverse effects were observed following inhalation of IB.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
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

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

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↗
PubMed1990

Bacteria and endotoxin enhance basophil histamine release and potentiation is abolished by carbohydrates.

Histamine release caused by anti-IgE, specific antigens and calcium ionophore A23187 was examined in leukocyte suspensions from healthy individuals and patients allergic to house dust mite and birch pollen. Staphylococcus aureus and LPS from Salmonella typhimurium were found to cause a synergistic enhancement of the release. The potentiation of mediator release by the bacteria and the endotoxin depends on a binding to the basophilocyte, followed by a non-transient event, since the potentiating effect persists after preincubation of the cells with the LPS followed by washout and leaving the cells for 30 min at 37 degrees C before stimulation with anti-IgE. The potentiation was abolished or reduced by galactose (10(-7) and 10(-6) M) and N-acetylglucosamine (10(-6) and 10(-5) M), acting by a binding to the basophil cell membrane, demonstrated by the persistence of effect after preincubation and washout of unbound sugar.

Adult↗
PubMed1989

Influenza A virus enhances IgE-mediated histamine release from human basophil leukocytes. Examination of the effect of viral neuraminidase and haemagglutinin.

Histamine release caused by anti-IgE was examined in leukocyte suspensions from 10 healthy individuals. Influenza A virus was found to enhance the histamine release but did not release histamine per se. When monoclonal antibodies directed against the viral neuraminidase were included in the samples, the potentiating effect of the virus was completely abolished. The same occurred using a neuraminidase inhibitor. However, monoclonal antibodies directed against the viral haemagglutinin also abolished the potentiation. A binding of virus to the basophil cell surface by haemagglutinin therefore seems to be necessary for the viral neuraminidase to cause potentiation of mediator release.

Antibodies, Anti-Idiotypic↗
PubMed1989

The effect of astemizole on bronchial hyperresponsiveness and exercise-induced asthma in children.

The ability of the new generation H1-receptor antagonist, astemizole, to prevent histamine-induced airway obstruction and exercise-induced asthma (EIA) was studied in 20 children with asthma. The study was a randomised clinically controlled trial of oral astemizole versus placebo in a cross-over study. In each of the two treatment periods the children were tested at days 0, 6, 15 and 22 of therapy. The two treatment periods were separated by a washout period of 50 days, and at each visit a bronchial challenge with increasing concentrations of histamine followed by an exercise test was performed, and peak flow and asthmatic symptom score were recorded daily. The children tolerated significantly higher mean concentrations of histamine when treated with astemizole compared with placebo (P less than 0.001). Astemizole postponed the response to exercise, but no change in the maximal response was found. No differences between the treatment periods were found regarding frequency of asthmatic symptoms or the daily recording of peak flow.

Administration, Oral↗
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↗
PubMed1986

Caliper skinfold measurements in newborns: analysis of a method.

Bilateral skinfold measurements on 10 different sites were performed blindly by 3 investigators in 118 newborns with a mean birth weight from 1,700 to 4,200 g. The caliper method was precise as judged by intra- and interobserver variances. Precision was independent of skinfold thickness, and not related to amount of training. Bilateral measurements of skinfolds over the quadriceps, pectoral and biceps muscles carried the highest precision. Precision was significantly increased by combination of these 3 measurements. There was no significant difference between the precision of these 3 bilateral measurements and 5 selected unilateral sites. For clinical practice, we recommend cumulated measurements of right-sided skinfolds over the quadriceps, pectoral, biceps and triceps muscles and subscapular skinfold.

Female↗