Biomedical subjects

J Kühr

Publications and source records attributed to J Kühr.

At least 19 recordsLinked to original sources

PubMed2001

[Lung function reference data in school-age children].

UNLABELLED: The practical interpretation of lung function data depends to a very great extent on the quality of reference values. METHODS: From a population of n = 2615 schoolchildren between 6 and 12 years of age 15,404 lung function measurements were taken in accordance with commonly accepted guidelines. In the present study the validity of reference equations from the literature is examined with regard to our measured data. RESULTS: Employing linear regression analysis, the natural logarithm (ln) of forced vital capacity in ml (FVC) and expiratory volume in one second in ml (FEV1) were explained on the basis of the equation ln y = a + b* ln x (y = FVC, FEV1 (ml); x = height (cm)). Analyses were performed for girls (lnFVC = -4.8789 + 2.5504* lnheight, lnFEV1 = -4.3078 + 2.4070* lnheight) and boys (lnFVC = -4.5241 + 2.4917* lnheight, lnFEV1 = -3.7338 + 2.2985* lnheight), separately. Our coefficients correspond best to the literature dealing with a population of the same age group. On the other hand, for example, if reference values are derived from equations from the literature for the age group 6 to 18 years, they result at 6 years in an underestimation of the volume measured by us (FVC -150 ml) and at 12 years to an overestimation (FVC + 120 ml). CONCLUSIONS: The extent of the proven systematic deviations of the reference values from the measured values is of clinical and epidemiological relevance. To avoid misinterpretations, special reference values should be applied for preadolescents, at least with regard to FVC and FEV1.

Body Height↗

PubMed2001

[Allergen immunotherapy - a position paper of the German society for allergology and clinical immunology].

Mechanisms of allergen immunotherapy (AIT) are complex inducing numerous immunological effects. Successful AIT is most likely based on a functional switch of and tolerance induction in specific T cells downregulating allergic hypersensitivity and inflammation. Subcutaneous AIT for allergic rhinoconjunctivitis and allergic asthma has been successfully assessed in controlled studies with several clinically important allergens (i. e. birch-, grass- and mugwortpollen, dust mites, animal dander) and has shown convincing clinical efficacy. Considered as the only causal treatment besides allergen avoidance at present, AIT can alter the natural course of allergic diseases. Hymenopteravenom hypersensitivity (to bee- and wasp venom) treated with AIT gives the best results compared to AIT with other allergens. AIT is indicated in patients with IgE-mediated sensitizations and corresponding clinical symptoms to allergens, which do not or hardly permit allergen avoidance and which are available as suitable extracts. Decisions about indication and allergen selection should only be made by a physician with certified training or qualified knowledge and skills in allergology. AIT is administered by physicians experienced in this therapy. After addressing tolerability and present status of health the recommended or individually adjusted does is injected and precisely documented, followed by a mandatory waiting period of 30 minutes. Indication for and application of AIT in children are quite similar compared to the treatment of adults. Children tolerate AIT very well and benefit especially from its immunomodulatory effects. Risk factors for and results of unwanted systemic effects can effectively be minimized by training of the staff members involved, adhering to safety standards and immediate emergency treatment. Modified allergens, recombinant proteins and immunomodulatory adjuvants created by basic research are promises for an improved efficacy of AIT with reduced unwanted effects in the future.

Allergens↗

PubMed2000

Preventive effect of 2 and 10 mg of sodium cromoglycate on exercise-induced bronchoconstriction.

UNLABELLED: This double-blind, randomised and cross-over study was designed to compare the preventive effect against exercise-induced bronchoconstriction (EIB), defined as the percentage decrease in FEV1 > or = 15% after 6 min of exercise, of 2 mg and 10 mg of sodium cromoglycate (SCG), administered through a metered dose inhaler via spacer, in asthmatic children. Each of the 30 subject (age 11.6 +/- 3.2 years) was tested on five occasions. For inclusion, EIB in test1 was required. In tests 2 to 5, all subjects inhaled 2 mg or 10 mg of SCG 20 min and 120 min before exercise in a randomised order. In order to assess excretion of eosinophil protein X (EPX) accompanying EIB, urine samples were collected before and after exercise. The mean percentage fall in FEV1 (+/- SD) in test 1 was 26.8 +/- 9.8%. Inhalation of 2 mg and 10 mg of SCG 20 min before exercise provided a significant preventive effect in 83% and 77% and inhalation 120 min before exercise provided a preventive effect in 63% and 70%, respectively (n = 30). Variance analysis did not reveal a statistically different absolute fall in FEV1 after exercise when both doses (120 min before exercise) were compared (P = 0.356). In an unselected subgroup of 12 children, urinary EPX increased after the challenge without SCG premedication (test 1) (mean change: +48.7 micrograms/mmol creatinine, P = 0.034), whereas no significant increase was found in case of SCG premedication (mean change in microgram/mmol creatinine): 2 mg/20 min: +12.1; 2 mg/120 min: +8.5; 10 mg/20 min: -10.4 and 10 mg/120 min: -23.5; P > 0.1). CONCLUSION: Administration of 10 mg of sodium cromoglycate is no more effective in preventing exercise-induced bronchoconstriction than 2 mg regardless of whether the medication is given 20 or 120 min before exercise. The preventive effect of sodium cromoglycate on exercise-induced bronchoconstriction in asthmatic children is associated with the inhibition of urinary eosinophil protein X excretion.

Administration, Inhalation↗

PubMed2000

Eosinophil cationic protein and eosinophil protein X in the nasal lavage of children during the first 4 weeks of life. SPACE Collaborative Study Team.

Eosinophil cationic protein (ECP) and eosinophil protein X (EPX) are well established as markers of eosinophil activation. We analyzed ECP and EPX concentrations in nasal lavage fluids (NALF) of 378 neonates during their first 4 weeks of life. Inclusion criteria were a positive history of parental allergy and a positive skin prick test or specific IgE (RAST class > or = 2) against at least one out of a panel of common aeroallergens in one or both parents. Twenty-four infants with no history of parental allergy were used as controls. A volume of 2 ml of 0.9% saline was instilled into each nostril and immediately recovered by a suction device. ECP and EPX were analyzed by radioimmunoassay. In 65 samples of three consecutive lavages, EPX was detected in nine samples (13.8%) in the control group, whereas it was detected in 197/360 samples (54.7%) in the study population. The corresponding figures for ECP were 17/65 (26.2%) in the control group and 173/365 (47.4%) in the study group. Both proteins showed a skewed distribution (median/5-95th percentiles for ECP: 0 microg/l [0-69.4] and EPX: 6.6 microg/l [0-73.2]). The differences between the control group and the study group were statistically significant, regardless of the allergic disease of the parents. In children of allergic parents, activation proteins of the eosinophil granulocyte are released on the nasal mucosal surface in about 50% of the studied population at the age of 4 weeks. This early onset of eosinophil activation in the nasal respiratory epithelium may reflect a genetic predisposition to allergy or early exposure to allergens.

Blood Proteins↗

PubMed2000

Eosinophil-derived proteins in nasal lavage fluid of neonates of allergic parents and the development of respiratory symptoms during the first 6 months of life. Collaborative SPACE team. Study on the Prevention of Allergy in Children in Europe.

BACKGROUND: Eosinophilic airways inflammation forms the pathophysiologic basis for a proportion of children at risk of developing recurrent wheezing. Early preventive measures and/or anti-inflammatory treatment may be guided by the identification of such children. METHODS: We studied upper-airways inflammation by nasal lavage in a cohort of 397 infants within the first 4 weeks of life. They participated in an international multicenter study on the prevention of allergy in Europe (SPACE-Biomed II Program). A volume of 2 ml of prewarmed 0.9% saline was instilled into each nasal cavity and immediately re-collected by a suction device. The average recovery was 502 microl (SD: 311 microl). The concentrations of eosinophil cationic protein (ECP) and eosinophil protein X (EPX) were determined by RIA analysis. RESULTS: ECP was detectable (>2 microg/l) in 47% of samples (173/365) and EPX (>3 microg/l) in 54.7% (197/360). Children with a doctor's diagnosis of a wheezy bronchitis within the first 6 months of life (n = 40) had significantly higher ECP and EPX concentrations in the nasal lavage at 4 weeks of age (median ECP: 14 microg/l; 5-95th percentile: 0-122.4 microg/l) than children without such diagnosis (median ECP: 0 microg/l; 5-95th percentile: 0-86.6 microg/l; P<0.05). Corresponding figures for EPX were 12.14 microg/l (0-148.98 microg/l) vs 7.5 microg/l (0-81.46 microg/l; P<0.05). No associations between nasal ECP/EPX and the development of food allergy or eczema were observed. CONCLUSIONS: Increased nasal ECP and EPX in the first 4 weeks of life are associated with wheezing in 6-month-old infants at increased risk of atopic disease. We suggest that this might be related to a general tendency for a Th2 cytokine pattern in these young infants and subsequent trafficking of eosinophils into the nasal mucosa, or it might be a consequence of intrauterine allergen exposure.

Blood Proteins↗

PubMed2000

[Reproducibility in induced sputum in children with asthma].

In asthmatic children sputum-induction with hypertonic saline is useful to quantify the eosinophilic inflammation. However, only few data are available about feasibility and safety of the procedure in children. Therefore, taking 9 non-atopic healthy control children (mean age 11.8 years) and 34 asthmatic children (mean age 11.4 years), inhaling n = 25 Budesonid (400-1200 micrograms/die) and n = 9 DNCG (60 mg/die), sputum induction was performed twice within 6 weeks. Briefly, 10 minutes after inhalation of 200 micrograms salbutamol subjects inhaled hypertonic saline (3, 4 and 5%) for in all 30 minutes, while all 5 minutes lung function was checked and expectoration of sputum was supported. Adequate sputum plugs were separated from contaminating saliva and processed immediately employing native chamber and cytospin cell count as well as measurement of eosinophilic cationic protein (ECP). Sputum-induction could be performed in 84 out of 86 planed tests (97.7%) without any objective clinical adverse effects. The mean fall in FEV1 was 3.0%, the maximum 11.0%. The reproducibility of eosinophil, neutrophil and lymphocyte differential cell count (5-95%-values Test1: 0.0-4.2%, 0.8-11.4%, and 3.2-35.1%, respectively) was moderate for eosinophils and neutrophils (Intraclass-Correlation-Coefficient (ICC) 0.41) as well as for lymphocytes (ICC = 0.49). For ECP 5-95%-values Test1: 39.8-8000.0 micrograms/l) only a fair reproducibility (ICC = 0.24) was found. The ICC levels for total cell count (ICC = 0.31) and for weight of the sputum plug (ICC = 0.30) were also fair. Based on the procedure presented induced sputum is a feasible and safe method in childhood. The differential sputum cell count of eosinophils, neutrophils and lymphocytes can be recommended as parameters with moderate reproducibility.

Adolescent↗

PubMed1999

Lack of correlation between CFTR expression, CFTR Cl- currents, amiloride-sensitive Na+ conductance, and cystic fibrosis phenotype.

Cystic fibrosis (CF) is characterized by defective Cl- and enhanced Na+ conductance, both due to malfunction of the cystic fibrosis transmembrane conductance regulator (CFTR) protein in airway epithelial cells. In the present study we examined whether expression of CFTR mRNA (CFTR messenger ribonucleic acid) is different in airway epithelia derived from either CF patients or healthy volunteers. Moreover, we tried to correlate differences in epithelial Cl- and Na+ conductance with the level of CFTR mRNA expression and studied whether these properties correlate to the clinical phenotype of CF patients. To that end, CFTR mRNA was determined by means of quantitative reverse transcriptase polymerase chain reaction (RT-PCR) and cyclic adenosine monophosphate (cAMP)-activated Cl- and epithelial Na+ conductances were examined in airway epithelial cells using microelectrode techniques. Complementary in vitro data were obtained from cultured CF and non-CF airway epithelial cell lines. Genotype and Shwachman score were assessed for each patient. We found variable levels of CFTR mRNA expression in airway cells of both CF patients and healthy volunteers. As expected, epithelial Na+ conductance was enhanced and CFTR Cl- conductance was absent in airway cells from CF patients. However, CFTR mRNA expression did not correlate with either electrophysiological properties or Shwachman scores obtained from CF patients. In addition, CFTR mRNA expression did not correlate to Cl- conductance in cultured CF and non-CF airway epithelial cells. These results indicate a lack of correlation between levels of CFTR mRNA and CFTR function, and that only small amounts of CFTR are required for expression of the CFTR Cl- conductance.

Amiloride↗

PubMed1999

Lung function growth and ambient ozone: a three-year population study in school children.

We followed a cohort of 1,150 children for 3 yr to investigate long-term effects of ambient ozone. Nine study sites were selected on the basis of air-quality data to represent a broad range of ozone exposure. In 1994, 1995, and 1996 lung function was recorded biannually, always before and after summertime. The effect of ozone was analyzed with regression analyses and study-site, a child's sex, atopy, passive smoking, baseline lung function, and increase in height were considered as confounding variables. A negative effect of summertime ozone on the pre- to post-summer-time change in FEV(1) (ml/d) was present in 1994 (beta = -0.019 ml/d/ppb; p < 0.01) and in 1995 (beta = -0.017 ml/d/ ppb; p < 0.05), but not in 1996 (beta = 0. 004 ml/d/ppb; p = 0.6); corresponding estimates for FVC were in 1994: beta = -0.022 ml/d/ppb, p < 0.005; 1995: beta = -0.018 ml/d/ppb, p < 0.05; and 1996: beta = 0.006 ml/d/ppb, p = 0.46. When all three study years were considered simultaneously, i.e., the changes in lung function between each of two subsequent surveys being the dependent variable, summertime ozone was associated with a lesser increase in FEV(1) (beta = -0.029 ml/d/ppb; p < 0.001), FVC (beta = -0.018 ml/d/ppb; p < 0.001), and MEF(50) (beta = -0.076 ml/s/d; p = 0.001). No consistent associations were observed for lung function and NO(2), SO(2) and PM(10). Long-term ambient ozone exposure might negatively influence lung function growth.

Air Pollutants↗

PubMed1998

Determinants of eosinophil cationic protein in nasal lavages in children.

BACKGROUND: Nasal lavages are increasingly used to assess airways inflammation in children. However, there are no studies assessing how measurement error as well as biological influences contribute to the concentration of nasal inflammatory parameters in a population based survey. OBJECTIVE: To investigate determinants of concentration of eosinophil cationic protein (ECP) in nasal lavages we studied 147 schoolchildren (mean age 8.1 years, SD 0.6 years) by repeated nasal lavages/year over a 2 year period. METHODS: Standardized questionnaires were completed by the parents each year. A skin-prick test with seven aeroallergens (birch, cat, dog, hazel, weeds, Dermatophagoides pteronyssinus and D. farinae) was performed. One hundred and one children could perform valid lavages at least five times a year. As a measure of reproducibility the intraclass coefficient of reliability was calculated. RESULTS: The intraclass coefficient of reliability was 0.27 over all observations suggesting that about a quarter of total variance is due to between-subject variance. Taking means over each year increased reliability to 0.60. Linear regression analyses with ECP being the dependent variable demonstrated significant higher values for boys (beta=12.26; P < 0.01), children sensitized to seasonal (beta=34.27; P=0.02) but not to perennial allergens (beta=-4.44; P=0.57), and for children with a serous (beta=10.01; P=0.01) or purulent rhinitis (beta=22.45; P < 0.001). CONCLUSION: Assessment of inflammatory mediators in nasal lavages is a useful tool for epidemiological paediatric studies. However, due to the relatively high intraindividual variability of ECP concentrations multiple lavages are necessary to characterize the individual.

Analysis of Variance↗

PubMed1998

Cholinergic ion secretion in human colon requires coactivation by cAMP.

Cl- secretion in the colon can be activated by an increase of either intracellular Ca2+ or cAMP. In this study we examined a possible interdependence of the two second-messenger pathways in human colonic epithelium. When measured in a modified Ussing chamber, carbachol (CCH; 100 micromol/l, basolateral), via an increase in cytosolic Ca2+ concentration ([Ca2+]i), activated a transient lumen-negative equivalent short-circuit current (Isc) [change (Delta) in Isc = -79.4 +/- 7.5 microA/cm2]. Previous studies indicated that intracellular Ca2+ directly acts on basolateral K+ channels, thus enhancing driving force for luminal Cl- exit. Increased intracellular cAMP (by basolateral addition of 100 micromol/l IBMX and 1 micromol/l forskolin) activated a sustained lumen-negative current (DeltaIsc = -42.4 +/- 7.2 microA/cm2) that was inhibited by basolateral trans-6-cyano-4-(N-ethylsulfonyl-N-methylamino)-3-hydroxy-2, 2-dimethyl&2-chromane (10 micromol/l), a blocker of KvLQT1 channels. In the presence of elevated cAMP, the CCH-activated currents were augmented (DeltaIsc = 167.7 +/- 32.7 microA/cm2), suggesting cooperativity of the Ca2+- and cAMP-mediated responses. Inhibition of endogenous cAMP production by indomethacin (10 micromol/l) significantly reduced CCH-activated currents and even reversed the polarity in 70% of the experiments. The transient lumen-positive Isc was probably due to activation of apical K+ channels because it was blocked by luminal Ba2+ (5 mmol/l) and tetraethylammonium (10 mmol/l). In the presence of indomethacin (10 micromol/l, basolateral), an increase of cAMP activated a sustained negative Isc. Under these conditions, CCH induced a large further increase in lumen-negative Isc (DeltaIsc = -100.0 +/- 21.0 microA/cm2). We conclude that CCH acting via [Ca2+]i can induce Cl- secretion only in the presence of cAMP, i.e., when luminal Cl- channels are already activated. The activation of a luminal and basolateral K+ conductance by CCH may be essential for transepithelial KCl secretion in human colon.

Adolescent↗

PubMed1997

Aromatic hydroxylation in nasal lavage fluid following ambient ozone exposure.

Ozone at ambient concentrations affects lung function and initiates an inflammatory response of the airways. However, the underlying mechanisms are poorly understood. In vitro studies have shown that ozone reacts with water to give reactive hydroxyl radicals capable of oxidizing a wide range of biomolecules. We conducted a study to determine if in vivo hydroxyl radical attack on human airways occurs under natural exposure to ozone. The relation of orthotyrosine to para-tyrosine as a measure of hydroxyl radical attack was analyzed in nasal lavage samples of 44 primary school children in an epidemiologic study. Repeated nasal lavages were performed between May and October 1991 both following "low" (daily half-hour maximum < 140 micrograms/m3, approximately 70 ppb) and "high" (daily half-hour maximum > 180 micrograms/m3, approximately 90 ppb) ozone exposure. Concomitantly, lung function tests were performed. On average, 11.6 (6-16) nasal lavages were performed for each of 24 study days (10 days following "low" ozone exposure and 14 days following "high" ozone exposure). Average ortho-tyrosine (median; 5-95% percentile) for each child was 0.037 mumol/L (0.016-0.064 mumol/L) and average para-tyrosine was 15.7 mumol/L (9.8-24.1 mumol/L). Ortho-tyrosine (as percentage of tyrosine) was significantly higher following days with "high" ozone exposure (0.18%) vs. days following "low" ozone exposure (0.02%; p = .0001). Ortho-tyrosine showed an inverse relationship with forced vital capacity (p = .01) but was not related to inflammation of the upper airways as assessed by cell counts of polymorphonuclear neutrophils. Hydroxyl radical attack subsequent to ambient ozone occurs in the upper airways of healthy children and is related to lung function decrements.

Air Pollutants↗

PubMed1997

Traffic-related NO2 and the prevalence of asthma and respiratory symptoms in seven year olds.

The aim of this study was to determine whether outdoor nitrogen dioxide (NO2) was associated with the prevalence of asthma and respiratory symptoms. In eight nonurban communities, 843 children resident for a minimum of 2 yrs were studied. Since industrial sources of air pollution were at least 20 km away from the study communities, NO2 was considered to primarily indicate traffic-related air pollution. NO2 was recorded at central monitors, and the 3 yr mean exposure was calculated. Asthma and respiratory symptoms were assessed according to the International Study on Asthma and Allergy in Childhood. Prevalence of asthma at some time ("ever asthma") was associated with long-term NO2. In parallel with increasing levels of NO2 (community specific 3 yr mean 6.0-17.0 parts per billion (ppb)), asthma prevalence was 2.5, 1.4, 1.6, 2.3, 3.4, 3.6, 7.6 and 8.5%, respectively (p=0.002 for trend). The prevalence odds ratios (PORs) for "ever asthma", following adjustment for gender, age, parental education, passive smoke exposure, type of indoor heating, and parental asthma, were 1.28 (95% confidence interval (95% CI) 0.20-7.98), 2.14 (95% CI 0.40-11.3) and 5.81 (95% CI 1.27-26.5), when each of two communities with low, regular and high NO2, respectively, were compared with the two communities with very low NO2. For symptoms "wheeze" (adjusted PORs for increased NO2: 1.47, 1.23 and 2.27) and "cough apart from colds" (adjusted PORs for increased NO2: 1.49, 1.93 and 2.07), a similar trend was seen. In this study a significant relationship was observed between traffic-related nitrogen dioxide and the prevalence of asthma and symptoms. Whether this association is causal has to be tested in longitudinal studies.

Asthma↗

PubMed1993

Relation between response to exercise and diurnal variability of peak expiratory flow in primary school children.

BACKGROUND: Variability in peak expiratory flow (PEF) has been proposed as a simple method of screening for asthma in epidemiological studies. This study was designed to assess whether the bronchial response to exercise and the diurnal variation in PEF identified the same subjects. METHODS: Bronchial response to a free running exercise test was assessed in a cohort of 918 seven year old children and was compared with variability of PEF as assessed by twice daily recordings for a one week period. Mini Wright peak flow meters were used throughout the study. RESULTS: Baseline PEFs of both tests were highly correlated but there was no significant correlation between a response to exercise and variability of PEF. Of 33 children with a physician's diagnosis of asthma, 18 had at least one abnormal test, but only five children were abnormal in both tests, showing that the tests did not identify the same subjects. CONCLUSION: Increased variability of PEF, as well as a response to exercise, was associated with respiratory symptoms, but only a response to exercise was closely associated with atopy (defined as a positive skin test to any of seven aero-allergens).

Asthma↗

PubMed1993

Influence of maternal smoking on variability of peak expiratory flow rate in school children.

Diurnal variability of peak expiratory flow rates (PEFRs) was assessed in 1,237 children. The PEFR was measured twice daily over a 1-week period. As an index of variability, the log of a week's mean of daily amplitude was calculated. Linear regression analyses revealed a significant positive association between maternal smoking and the variability of PEFR for nonasthmatic children. For these children, exposure to maternal smoking was associated with a 13.7 percent increase (confidence interval [CI], 3.8 to 24.7 percent) in PEFR variability. For asthmatic children an effect was found for nonatopic (54.7 percent increase; CI, 5.5 to 226.8 percent) but not for atopic children (-8.5 percent change; CI, -41.2 to 42.3 percent). In the latter group, there was evidence that mothers changed their smoking habits subsequent to the development of disease in their children. We conclude that exposure to maternal smoking can increase the variability of PEFR and thus might contribute to the development of asthma.

Adult↗

PubMed1993

[Longitudinal study of bronchial hyperreactivity using the carbachol test with school children].

STUDY DESIGN: Bronchial hyperresponsiveness of 476 schoolchildren (10.8 +/- 2.3 years) was studied three times at 12 months' intervals. The cumulative dose of 400 micrograms carbachol was applied in 50 + 50 + 100 + 200 micrograms steps. A fall of FEV1 of at least 15% was regarded as positive reaction. The test was save, as no severe obstruction was observed, only three children withdrew because of unpleasant cough. RESULTS: Reactivity was observed in 19.1, 10.0, and 5.2% of children at the occasion of the first, second and third test (sensitivity/specificity for prevalence of physician diagnosed asthma: 70/83, 35/91, and 24/96%, respectively). Reactivity was age dependent (7-11 years: 35%, 12-16 years: 18%), not influenced by sex, and the relative risk to be reactive was 1.9 in children 2-3 weeks after a respiratory tract infection. CONCLUSION: For epidemiological purposes carbachol provocation test--like other unspecific bronchial provocation tests--is inappropriate as a single test to classify individuals as asthmatics.

Adolescent↗

PubMed1993

[Variability of peak expiratory flow in an unselected sample of school children].

In the framework of an epidemiological study, the information by peak flow variability (PEFV) was compared to the history of asthma in a non-selected population of primary-school children (n = 1812). PEFV as assessed by twice daily recordings of PEF for a one week period (n = 1237) was calculated as average of daily amplitudes (AVAM: average amplitude mean) in the case of at least complete data for five days (n = 991). Elevated PEFV defined as AVAM > 12%, was cross-tabulated with the asthma history (self-administered questionnaire). The median (90%-confidence-interval) of AVAM is 6.3% (2.2-15.9%). In 11.2% (n = 111) of the population, AVAM > 12% occurred). The sensitivity of AVAM > 12% with regard to "doctor's diagnosed asthma" (n = 35) is 37%. Under exclusion of children with recurrent wheezy bronchitis a specificity for AVAM > 12% of 90% is found. Our data on primary-school children suggests that PEFV is a specific but only slightly sensitive measurement with regard to previously diagnosed bronchial asthma.

Adult↗

PubMed1993

[Asthma screening with a standardized running test].

Exercise induced asthma is a common feature of asthma in childhood. We performed a standardized free running test in 1461 primary schoolchildren in first grade (mean age: 7.3 years). A decrease of peak expiratory flow of at least 15% after a 6 minutes exercise period was considered a positive response. For a lifetime prevalence of a physician's diagnosis of asthma the sensitivity of the test was 35.4% and the specificity 94.3%. A positive response was associated with atopy (defined as a positive skin prick test) and with the clinical severity of asthma.

Asthma↗

PubMed1992

[Urinary N-methylhistamine excretion. Following exogenous histamine administration and allergy/exercise-induced bronchoconstriction].

Histamine is partly metabolized to a stabile metabolite N-methyl-histamine and excreted in the urine. We analysed the degradation of infused histamine and the N-methyl-histamine-excretion in atopic and normal individuals as in patients with a bronchoconstriction due to allergen/exercise challenge. N-methyl-histamine was determined by a newly developed radioimmunoassay. 60 controls and 38 atopic individuals were investigated. There is a proportional increase of N-methyl-histamine in the urine in young children. However, no significant difference between allergic and non-allergic individuals was found. After parenteral administration of a standardized amount of histamine 12% of the applied amount was secreted in the urine as N-methylhistamine. The most significant increase of N-methylhistamine-excretion was observed in the first hour after application. Only an 0.1% rise of N-methyl-histamine was observed following an oral administration of histamine. Neither bronchial challenge with specific allergen nor physical exercise elicited significant changes of N-methylhistamine excretion. The secretion of N-methyl-histamine demonstrates the degradation of histamine in the circulation, the measurement oft this metabolite in the urine should be considered when analysing the cause of severe systemic allergic reaction as anaphylaxis but not asthma or atopic disposition.

Adolescent↗