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Biomedical subjects

D S Postma

Publications and source records attributed to D S Postma.

At least 235 records · Page 13Linked to original sources
PubMed1995

House dust mite exposure in asthmatic and healthy children: the difference is carpeting.

AIM: To determine whether house dust mite (HDM) exposure in living rooms and bedrooms is higher in asthmatic children than in those of age and sex matched healthy children, living in the same area. METHODS: Types of floor-coverings were recorded and dust samples were collected by vacuum cleaning the total area of living rooms and bedrooms; Der p I and Der p II per gram fine dust concentrations were assessed. Twenty-five asthmatic children (RAST HDM > or = class 3, age 6-12 years) and 25 healthy children participated in the study. RESULTS: The frequency of cleaning and prevalence of smooth floor-coverings in bedrooms of asthmatic children were significantly higher. There were no differences in living rooms in this respect. The amount of fine dust/m2 floor space was significantly lower in bedrooms of asthmatic children. Concentrations of HDM were low and no differences in Der p I and Der p II concentrations were observed between the two groups (asthmatic children: Der p I living room: 1.1 (0.04-59.4 micrograms/g), bedroom: 0.5 (below detection--19.3 micrograms/g); nonasthmatic children: Der p I living room: 1.4 (below detection--27.5 micrograms/g), bedroom: 0.9 (below detection--68.8 micrograms/g. Smooth floor coverings contained significantly less fine dust, Der p I, and Der p II than carpeted floors. CONCLUSIONS: Low HDM concentrations are a general finding in Dutch dwellings in the present generation of children. We observed a higher cleaning frequency, and more smooth floor coverings in bedrooms of asthmatic children than of healthy children, yet HDM concentrations were not significantly different. The latter can be explained by the observation that only 40% of the asthmatic children had smooth floor coverings in their bedrooms. Smooth floor coverings contain less fine dust and lower concentrations of Der p I and Der p II than carpeted floors.

Allergens↗
PubMed1995

Relation between respiratory symptoms, pulmonary function and peak flow variability in adults.

BACKGROUND: A study was carried out to determine whether subjects with respiratory symptoms are more likely to have impaired lung function or increased airway lability, and to quantify these relationships in a population of adults. METHODS: Data were collected from 511 participants (aged 20-70 years) from the Dutch part of the European Community Respiratory Health Survey (ECRHS). The symptoms analysed were: wheeze, dyspnoea > or = grade 3, nocturnal dyspnoea, cough and phlegm, and history of allergy. Lung function was measured by peak expiratory flow (PEF) and forced expiratory volume in one second (FEV1). PEF variability was used as an index for bronchial lability. RESULTS: Both FEV1 and PEF were decreased with increasing numbers of symptoms. Subjects with one symptom had an increased risk of having an FEV1 value of < 70% (OR = 4.2) and this risk increased with an increasing number of symptoms. Subjects with three or more symptoms had an increased risk of having a PEF value of < 70%, a diurnal variation in PEF of > 10% (both OR = 4.4), and an increased risk of high between day variation (OR = 6.6). CONCLUSIONS: Subject-reported symptoms are related to impaired lung function and to increased variability of peak flow.

Adult↗
PubMed1995

Long term benefits of rehabilitation at home on quality of life and exercise tolerance in patients with chronic obstructive pulmonary disease.

BACKGROUND--Pulmonary rehabilitation has been shown to have short term subjective and objective benefits for patients with chronic obstructive pulmonary disease (COPD). However, appropriately controlled studies have not previously been performed, nor have the benefits of different types of continuation programme for rehabilitation been investigated. Both these problems have been addressed in a single study of the long term effects of once monthly physiotherapy versus once weekly physiotherapy at home after a comprehensive home rehabilitation programme on quality of life and exercise tolerance in patients with COPD. METHODS--Thirty six patients with severe airways obstruction (mean SD) forced expiratory volume in one second (FEV1) 1.3(0.4) 1, FEV1/inspiratory vital capacity (IVC) 37.2(7.9)%) were studied. Twenty three patients followed a rehabilitation programme at home for 18 months consisting of physiotherapy and supervision by a nurse and general practitioner. During the first three months all 23 patients visited the physiotherapist twice a week for a 0.5 hour session. Thereafter, 11 patients (group A) received a session of physiotherapy once weekly while 12 patients (group B) received a session of physiotherapy once a month. The control group C (13 patients) received no rehabilitation at all. Quality of life was assessed by the Chronic Respiratory Questionnaire, exercise tolerance by the six minute walking distance, and lung function by FEV1 and IVC. Outcome measures were assessed at baseline and at three, six, 12, and 18 months. RESULTS--Long term improvements in quality of life were found in patients in groups A and B, but not in those in group C compared with baseline, but these only reached significance in group B at all time points. Patients in group B had a higher quality of life than those in group C only at three and 12 months. There was a decrease in both six minute walking distance (at 12 and 18 months) and IVC (at three, 12, and 18 months) in patients in group C compared with the baseline measurement. Between groups analysis showed no differences for six minute walking distance, FEV1, and IVC. CONCLUSIONS--This study is the first to show that rehabilitation at home for three months followed by once monthly physiotherapy sessions improves quality of life over 18 months. The change in quality of life was not associated with a change in exercise tolerance.

Exercise Tolerance↗
PubMed1995

Effects of propranolol inhalation on the diurnal increase in FEV1 and on propranolol airways responsiveness in atopic subjects with asthma.

BACKGROUND: Propranolol inhalation provocation tests are used to measure indirect airways responsiveness in the investigation of asthma. In this study the effects of repeated propranolol inhalation provocation tests within the same day on normal diurnal variation in the forced expiratory volume in one second (FEV1) and subsequent propranolol airways responsiveness were investigated. METHODS: Fifteen atopic asthmatic subjects were challenged with doubling concentrations of propranolol at 08.00 and 16.00 hours on the same study day and at 16.00 hours on a control day to exclude changes related to normal diurnal variation. RESULTS: Mean (SD) baseline FEV1 at 16.00 hours on the study day was 3.38 (0.23) 1, significantly lower than the value at 16.00 hours on the control day of 3.70 (0.24) 1 (p = 0.001). No differences were found between the geometric mean provocative concentration of propranolol causing a 20% fall in FEV1 (PC20) measured on the study day (08.00 hours, 9.3 mg/ml; 16.00 hours, 11.3 mg/ml) and on the control day (16.00 hours 9.3 mg/ml). CONCLUSIONS: The results suggest that propranolol provocation at 08.00 hours has a long lasting effect on FEV1, thereby counteracting the normal diurnal increase in diameter of the airways. This makes propranolol challenge tests less suitable for studying indirect airways responsiveness in the course of one day. Because the FEV1 does not return to control values, it is not possible to determine whether tachyphylaxis to repeated propranolol challenge with a time interval of up to eight hours occurs.

Adolescent↗
PubMed1995

Lymphocyte and macrophage activation in bronchoalveolar lavage fluid in nocturnal asthma.

Increased nocturnal airway narrowing is thought to occur as a consequence of an intensification of inflammatory processes at night. Lymphocyte and alveolar macrophage (AM) activation are thought to be associated with the clinical expression of asthma, and may be important in the occurrence of nocturnal asthma as well. The expression of CD25 and HLA-DR receptors on lymphocytes from bronchoalveolar lavage (BAL) and peripheral blood (PB) CD4+, as well as of CD14, IgG Fc, and CD11/CD18 leukocyte adhesion receptors on AM in BAL fluid and monocytes in PB, were determined at 16.00 and 04.00 h by flow cytometry. Their relationship with the occurrence of nocturnal asthma was investigated in eight nonatopic controls (Group 1) and 17 atopic asthmatic subjects, prospectively assigned to groups with a mean circadian peak expiratory flow (PEF) variation < 15% (Group 2) and > or = 15% (Group 3). The occurrence of an increased circadian variation in PEF in asthmatic subjects was on the whole not associated with a day-night fluctuation in lymphocyte numbers and subsets in PB or BAL fluid, nor with day-night changes in receptor expression on AM from BAL or monocytes from PB. The only exception was the presence of a greater day-night change in the proportion of HLA-DR-expressing CD4+ lymphocytes in the BAL fluid along with an increasing circadian PEF rhythm in asthmatic subjects (r = 0.68, p = 0.03). A further finding was that a lower number of BAL CD4+ lymphocytes at daytime was significantly related to a higher circadian PEF variation in asthmatic subjects (r = -0.66, p = 0.01).(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1995

Importance of total serum IgE for improvement in airways hyperresponsiveness with inhaled corticosteroids in asthma and chronic obstructive pulmonary disease. The Dutch CNSLD Study Group.

Airways hyperresponsiveness is a hallmark of asthma, and many patients with COPD also demonstrate hyperresponsiveness. Inhaled corticosteroids improve hyperresponsiveness, but the extent of improvement may vary considerably between patients. This study was designed to determine which patient characteristics predict these differences in response. Patients with mild to moderately severe obstructive airways disease (asthma and COPD) were selected if PC20 < or = 8 mg/ml and FEV1 < 95% confidence interval of predicted normal. They were followed for 2.5 yr, during which one-third received inhaled corticosteroids. The independent influences of baseline FEV1/IVC, bronchodilator response, PC20, smoking habits, allergy, age, and sex on the improvement in airways hyperresponsiveness with inhaled corticosteroids were analyzed. Total serum IgE was taken as a parameter of allergy, next to specific IgE for house dust mite, skin tests, and blood eosinophils. Total serum IgE was found to be the most important and single independent predictor of change in PC20 with inhaled corticosteroids: patients with a higher IgE had a greater increase in PC20 when administered inhaled corticosteroids than those with lower IgE levels. Alternatively, patients with a higher IgE who did not receive corticosteroids had a decrease in PC20 compared with patients with a lower IgE. This effect was most prominent in asthma but was inconsistent in asthmatic bronchitis and COPD. The level of IgE cannot be used to predict the response to inhaled corticosteroids in individuals accurately. Total serum IgE is the single most important predictor of change in PC20 with and without inhaled corticosteroids.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1995

Long-term circadian effects of salmeterol in asthmatic children treated with inhaled corticosteroids.

The present study was set up to investigate whether salmeterol in children with asthma already treated with inhaled corticosteroids (ICS) leads to a sustained bronchodilator effect and decreased bronchial responsiveness, both during the day and night. Furthermore, we investigated whether cessation of salmeterol leads to a rebound increase in bronchial responsiveness. Forty children with asthma (aged 7-15 yrs) using ICS participated in a randomized, double-blind, parallel study. They received either twice daily 50 micrograms salmeterol or placebo. FEV1 and provocative concentration of methacholine that caused a 20% fall in FEV1 (PC20) were measured at 4:00 P.M. and 4:00 A.M. at baseline and after 16 wk. The same measurements were performed at 4:00 P.M. at 8 h after the first dose, and after 1 and 8 wk. After cessation of the study drug, FEV1 and PC20 were measured at 12 and 20 h and after 1 wk. Overall mean FEV1 from 1 to 16 wk of treatment was significantly higher in the salmeterol group than in the placebo group (difference, 4.9 +/- 2.0%, p = 0.01). Evolution in time of FEV1 did not differ significantly between the two groups (p = 0.09). Overall mean PC20 from 1 to 16 wk of treatment was not significantly higher with salmeterol than with placebo (difference, 0.7 +/- 0.4 doubling dose [DD] p = 0.07); evolution in time of PC20 did not differ significantly between the two groups (p = 0.58).(ABSTRACT TRUNCATED AT 250 WORDS)

Administration, Inhalation↗
PubMed1995

Chronic respiratory symptoms and airway responsiveness to methacholine are associated with eosinophilia in older men: the Normative Aging Study.

Identification of subsets of patients with chronic obstructive lung disease (COLD) in order to determine disease outcomes and, possibly, the effects of treatment is an area of clinical interest. At present, it remains unclear which patients with COLD are most likely to benefit from anti-inflammatory therapy. We investigated this question in a community-dwelling sample of men. In this study, the relationship of chronic respiratory symptoms, airway responsiveness to methacholine, and skin test reactivity to peripheral-blood eosinophil and neutrophil counts was examined among 894 male participants in the Normative Aging Study (mean age 60 yrs; range 41-90 yrs). The symptoms considered were asthma, persistent wheeze, dyspnoea, chronic cough and phlegm. Responsiveness to methacholine was defined as a provocative dose producing a 20% fall in forced expiratory volume in one second (PD20FEV1) of < or = 8.6 mumol, a positive skin test as a wheal diameter of > or = 5 mm after subtraction of the diameter of any wheal reaction to a glycerin control, and eosinophilia as an eosinophil count of > or = 275 cells.mm-3 in peripheral blood. Chronic symptoms (odds ratio (OR) 2.0; 95% confidence interval (CI) 1.4-2.7), airway responsiveness (OR 1.7; CI 1.1-2.7), and the combination of symptoms and airway responsiveness (OR 3.4; CI 2.0-5.6) were positively and significantly related to peripheral-blood eosinophil counts. These relationships remained significant after adjustment for the effects of age and smoking, and after exclusion of asthmatic subjects. Symptoms and airway responsiveness combined were not significantly related to neutrophil counts.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1995

Frequency of nocturnal symptoms in asthmatic children attending a hospital out-patient clinic.

Since nocturnal symptoms indicate more severe asthma, we investigated their frequency in a hospital-based population of asthmatic children. Recognition of these symptoms offers the possibility to introduce appropriate treatment. We studied 796 consecutive children with asthma (mean (SD) age 9 (4) yrs) attending a hospital clinic, to determine whether these nocturnal symptoms predicted that daytime activities would be affected, and also the patients' perception of disease severity. At the end of a regular out-patient clinic visit, the answers to seven different questions concerning nocturnal symptoms in the previous 3 weeks were recorded. The forced expiratory volume in one second (FEV1) was > or = 90% predicted in 98% of the population that was able to perform lung function measurements (72% of the total population). In 38% of the patients with nocturnal symptoms, these symptoms were reported spontaneously. When asked for, nocturnal symptoms were reported by 47% of the children; 6% every night and 34% at least once a week. Cough was the most frequently reported symptom (31%). Children with nocturnal symptoms had a lower FEV1, scored their perception of asthma as more severe, and had their daytime activities affected more than those without nocturnal symptoms. Doctors should specifically ask about nocturnal symptoms, as not all patients with nocturnal symptoms report them spontaneously and they predict more severe disease.

Adolescent↗
PubMed1995

Peak inspiratory mouth pressure in healthy subjects and in patients with COPD.

The validity of peak inspiratory mouth pressure (P.PI-max) as a measure of inspiratory muscle strength was investigated by comparing it with sniff Pes in patients with COPD with respect to (1) learning effect, (2) reproducibility, and (3) measures of agreement. To assess the discriminating capacity of P.PImax, we compared the values in patients with COPD with those of healthy elderly subjects. Thirty-four patients (mean age, 62.5 years) with severe airways obstruction (FEV1, 44% predicted; FEV1/IVC, 37% predicted) and 149 healthy subjects (age > or = 55 years) were included. P.PImax was assessed during a maximal static inspiratory maneuver, while sniff Pes was assessed during a maximal sniff maneuver. Both maneuvers were performed from residual volume ten times on the same day. P.PImax showed no learning effect, while the sniff maneuver used seven attempts to obtain a maximal value. The intraindividual coefficients of variation of P.PImax and sniff Pes were 11.2% and 6.0%, respectively. Measures of agreement showed no significant discrepancies between the mean P.PImax and mean sniff Pes (0.29 kPa, p = 0.49). There was a significant correlation (r = 0.57, p < 0.001) between both measurements. P.PImax was significantly (p < 0.001) lower in both male (8.2 kPa) and female (6.2 kPa) patients with COPD compared with healthy men (11.0 kPa) and healthy women (8.8 kPa). We conclude that P.PImax is a valid and noninvasive assessment of inspiratory muscle strength.

Age Factors↗
PubMed1995

Adverse effects of eosinophilia and smoking on the natural history of newly diagnosed chronic bronchitis.

BACKGROUND: Little is known about risk factors for the progression of disease in individuals with newly developed chronic bronchitis (CB). In addition to the effects of smoking, there was specific clinical and epidemiologic interest in the importance of traits such as eosinophilia and wheezing, more commonly associated with asthma, in the progression of this disease. METHODS: We evaluated adult individuals with and without diagnosed CB longitudinally in a representative community population in Tucson, Ariz. These subjects were followed up for 13 years since 1972. Because we were interested in CB specifically, those with diagnoses of emphysema and asthma were removed from the data set. Initial level of FEV1 (%FEV1) and slopes in FEV1 were corrected for covariates and other important variables. RESULTS: As expected, persistent and newly diagnosed CB was significantly more common in current and ex-smokers. Furthermore, initial lung function was lower, and decline in FEV1 was steeper in smokers with persistent and newly diagnosed CB. Newly diagnosed cases had steeper declines in FEV1 (-6.84 mL/yr below grand mean of -11.18 mL/yr) than normal subjects (+0.95 mL/yr). The incidence rate of newly diagnosed CB was significantly higher in those with eosinophilia (13.7%) than without eosinophilia (6.7%). Finally, new cases with eosinophilia had similar initial %FEV1 (95.4 +/- 1%) but much larger declines in function than new cases without eosinophilia: -24.5 versus -16.6 mL/yr. Adverse effects of wheeze were largely explained by smoking and eosinophilia. CONCLUSION: Eosinophilia is an important aspect of CB in addition to smoking, and it should be considered in its evaluation. The presence of eosinophilia in newly diagnosed CB, with or without wheeze, may warn the clinician of the possibility of a rapid decline in FEV1.

Adult↗
PubMed1995

Evidence for two unlinked loci regulating total serum IgE levels.

Studies investigating the genetic control of total serum IgE levels are of major importance in understanding basic pathophysiologic mechanisms in atopy and asthma, since IgE levels predict onset and correlate with the clinical expression of these disorders. Previous analysis of data from 92 families, ascertained through a parent with asthma, showed evidence for recessive inheritance of high IgE levels with linkage to chromosome 5q. Since there was significant residual familial correlation in the one-locus segregation analysis, two-locus segregation and linkage analyses were performed. Segregation analyses provided evidence for a second major locus unlinked to the locus on 5q. Utilization of this two-locus model corroborates the previous evidence for linkage between this trait and markers on 5q31-q33. The LODs for the most informative marker D5S436 increased from 3.00 at 10% recombination to 4.67 at 9% recombination, when the two-locus model was used. Additional linkage studies are needed to map this second locus. These results demonstrate the importance of performing multilocus segregation and linkage analyses for quantitative traits that are related to the phenotype of a complex disorder. This approach has given further insight into the genetics of allergy and asthma by providing evidence for a two-locus model.

Asthma↗
PubMed1994

Evidence for a locus regulating total serum IgE levels mapping to chromosome 5.

Genetics studies of total serum IgE levels were performed since high IgE levels correlate with clinical expression of allergy and asthma. Families ascertained through a parent with asthma were genotyped for markers on 5q where there are multiple candidate genes that may influence the control of IgE and inflammation. Evidence for linkage of the IgE phenotype to 5q was obtained by both sib-pair and lod score analysis with evidence for recessive inheritance of high IgE levels from segregation analysis. These findings represent a major step in mapping genes important in the regulation of allergic responses and the pathogenesis of asthma.

Adult↗