Research needs in regard to determining the etiology of asthma.
Explore the source record for details and available documents.
Asthma↗
Biomedical subjects
B Burrows
Publications and source records attributed to B Burrows.
Pneumococcus-specific immunoglobulin E in cigarette smokers.
A relationship between elevated serum immunoglobulin E levels and smoking has been demonstrated in epidemiological studies. Allergy skin test data suggest that the excess immunoglobulin E of smokers is not specific for aeroallergens. It is possible that the excess immunoglobulin E is specific for microorganisms that often infect the lower respiratory tract of smokers. To investigate this possibility we utilized a radioallergosorbent test assay for detecting serum immunoglobulin E specific for Streptococcus pneumoniae, an organism commonly isolated from the respiratory tract of smokers with chronic bronchitis. We assayed sera of thirty smokers and thirty nonsmokers for immunoglobulin E specific for Streptococcus pneumoniae. Individual sera were considered positive for pneumococcus-specific immunoglobulin E if the binding was at least twice the non-specific binding at the total immunoglobulin E concentration of the particular serum. Eleven of the thirty sera of smokers and two of the thirty nonsmokers were positive for pneumococcus-specific immunoglobulin E. By chi-square analysis of these data, the prevalence of pneumococcus-specific immunoglobulin E was significantly greater in the smoking group compared with the non-smoking group (P less than 0.02). These results suggest that the excess immunoglobulin E of smokers is, at least in part, specific for microorganisms that infect the airways.
Adult↗
Longitudinal changes in forced expiratory volume in one second in adults. Methodologic considerations and findings in healthy nonsmokers.
Longitudinal changes in FEV1 (delta FEV1) have been examined in a sample of the general population of Tucson, Arizona. Adults with satisfactory spirometric tests in all 7 surveys performed over a period of 11 yr showed some between-survey differences in mean FEV1. Although small in absolute magnitude, such survey biases (which would be impossible to detect unless multiple spirometric tests were carried out on a relatively large group of subjects) could have a marked effect on calculated changes in FEV1 and may explain the widely divergent delta FEV1 values reported in the literature. After adjusting for survey biases, the relationships of delta FEV1 to age, sex, and body size were examined in "healthy" nonsmokers in the population who were followed for an average of 9.6 yr. The FEV1 showed an accelerating decline with age, and delta FEV1 was best explained by a model of proportional change in which it is a function of Age X Height3. Longitudinally determined delta FEV1 showed much less decline in function and a later apparent age of onset of decline than suggested by cross-sectional analyses. While small "learning effects" in longitudinal calculations cannot be excluded, most of the cross-sectional versus longitudinal differences are probably ascribable to past events that have adversely affected the FEV1 in older adults, thereby increasing cross-sectional age effects. Present findings also suggest that generally applicable "prediction equations" for delta FEV1 probably cannot be developed and that delta FEV1 values should only be compared between groups studied in an identical manner within a given study.(ABSTRACT TRUNCATED AT 250 WORDS)
Adult↗
Comparisons of asthma, emphysema, and chronic bronchitis diagnoses in a general population sample.
This report is an analysis of cases of obstructive lung disease diagnosed during the first 8 yr of a community study. Of 351 subjects who received a new diagnosis of asthma, emphysema, or chronic bronchitis from community physicians, 152 (44.5%) had a prior or concomitant diagnosis of another obstructive disease. Asthma developed most often in young subjects, emphysema in older subjects, and chronic bronchitis occurred in all age groups. Among older subjects, disease groups were surprisingly similar, with wheeze, dyspnea, and attacks of shortness of breath with wheeze all occurring frequently in diagnosed subjects, including those with emphysema. The majority of subjects who developed emphysema were males. In contrast, 72.8% of the asthma and chronic bronchitis subjects were females. These results suggest that physician bias may result in labeling male patients as emphysematous and female patients as asthmatic or bronchitic.
Adolescent↗
Vectorcardiographic and blood pressure correlates of obstructive pulmonary diseases in a community population.
Vectorcardiography was performed on 2,449 subjects, aged six years and older, in the Tucson (Ariz) Epidemiological Study of Airway Obstructive Diseases (AOD), 95 percent of the white non-Mexican Americans in the stratified cluster population sample. The objectives were to confirm previous relationships and to determine if hypothesized changes in the vectorcardiogram (VCG) could predict AOD. Trained nurse technicians performed the VCGs, which were read and interpreted by a cardiologist. Vectorcardiographic results were broadly interpreted for abnormalities. Also, calculated vector means and angles were compared to standard questionnaire responses for medical history, to maximum expiratory flow-volume variables, and to values for blood pressure; these were all corrected for sex, age, height, weight, and the ponderal index. Values were expressed as percentages of predicted. Over 80 percent of the VCGs were found to be normal. Measured hypertrophy was related to disease; there were significantly more abnormalities in those with histories of heart disease, hypertension, arteriosclerosis, and AOD, when examined by types of ventricular hypertrophy and VCG-identified heart disease or hypertension; findings of AOD and heart disease were also correlated significantly. Of all the ventricular hypertrophy, right ventricular hypertrophy (RVH), type C, was confirmed to be the predominant type associated with decreased pulmonary function in all smoking groups. Systolic blood pressure was related to RVH, type A, and diastolic 4 and 5 blood pressure with RVH, types A and B. The vectors' magnitude and angles were related to abnormality of pulmonary function in those with and without heart disease and AOD.
Adolescent↗
A prospective study of the natural history of asthma. Remission and relapse rates.
In this longitudinal study of a general population sample, remissions of asthma were common only during the second decade of life and were especially unusual in subjects ages 30 to 60 years on enrollment. Asthmatic subjects with severe symptoms, with reduced ventilatory function, or with a concomitant diagnosis of chronic bronchitis or emphysema on entry to the study were very unlikely to be in remission nine years later. Relapses of disease were common in subjects with a past history of asthma who were considered to be quiescent on enrollment to the study. Relapse rates tended to increase with age, at least up to the age of 70. Relapses were especially frequent among those "ex-asthmatics" who had persisting respiratory symptomatology on entry to the study.
Adolescent↗
Methodological considerations of epidemiological diagnoses in respiratory diseases.
Since epidemiological research depends extensively on questionnaire responses, a comparison of such responses with a standardized medical evaluation was conducted. It was found that standardized questionnaires do well in comparison for certain kinds of information on chronic conditions. However, clinical evaluations will elicit more information, specifically of a milder nature. It was concluded that standardized epidemiological questionnaires are satisfactory for survey of chronic conditions.
Adolescent↗
The epidemiology of asthma.
Significant strides have been made in recent years in the epidemiologic study of obstructive lung diseases including asthma. Community population samples are being evaluated prospectively and followed up longitudinally to document the appearance of morbidity and clinical diagnoses. Also, a variety of environmental, physiologic, and immunologic variables are being collected on a serial basis to correlate changes with the appearance (or disappearance) of recognizable disease. Unfortunately, until the semantics and diagnostic labeling of airway abnormalities becomes more precise, especially in the older population, the incidence and prevalence of disease will lack the precision it should have.
Adolescent↗
Estimates of C. immitis infection by skin test reactivity in an endemic community.
This report is a comparison of two delayed hypersensitivity skin test reagents, coccidioidin and Spherulin, available for detection of prior infection by Coccidioides immitis. Coccidioidin proved to be a somewhat more sensitive reagent (33.4 per cent positive, vs 29.6 per cent for Spherulin). This difference persisted in the subjects when grouped by age, sex, exposure history, or history of coccidioidomycosis. Skin test reactivity to both reagents declined with age. Independent of exposure history coccidioidin detected 7.3 per cent of the subjects who were not detected by Spherulin; Spherulin detected prior infection in only 3.5 per cent of the subjects not detected by coccidioidin. These results differ from those of previously reported studies.
Adolescent↗
Family concordance of IgE, atopy, and disease.
Family concordance of IgE was determined in 344 nuclear families that were studied in a community population of white families in the Tucson area. Total circulating IgE, after controlling for age, sex, smoking status, and skin test reactivity demonstrated a significant family concordance with the use of multifactional analysis of variance. This relationship was strongest among siblings, was significant as well between parents and children, and was not present between spouses. Skin test reactivity demonstrated independent family concordance with the same statistical methods. Reported diagnoses of asthma, wheeze, and allergic-rhinitis histories demonstrated a strong concordance of prevalence rates in families as well.
Adult↗
Family aggregation of pulmonary function measurements.
Family aggregation of pulmonary function measurements was analyzed in the nuclear families of the Tucson epidemiologic study of airway obstructive diseases (AOD). There were 271 parental pairs and their natural children who had satisfactory pulmonary function data. Initial regression analysis showed significant correlations of the pulmonary function variables after controlling for age and sex. Body habitus, as measured by the Ponderal Index, was highly aggregated as well. Pulmonary function measurements were aggregated in families independent of family size, reported diagnosed AOD, and children's smoking, even though both asthma and smoking showed significant familial aggregation. After controlling for the familial aggregation of body habitus, a major determinant of pulmonary function, there was no remaining independent aggregation of pulmonary function measurements. It was also determined that parental passive smoking had no effect on children's pulmonary function measurements.
Adolescent↗
Risk of chronic obstructive pulmonary disease. Collaborative assessment of the validity of the Tecumseh index of risk.
Predictors of chronic obstructive pulmonary disease (COPD) have been identified in the prospective epidemiologic study of the population of Tecumseh, Michigan. Risk of developing COPD within 10 yr can be estimated from a profile that includes as risk factors age, sex, cigarette smoking habits, and forced expiratory volume in one second (FEV1). The index of risk placed 63% of male incidence cases and 64% of female incidence cases in the top 10% of the risk distribution and 81% of male and 86% of female COPD cases in the top 20% of the risk distribution for Tecumseh. The validity of the Tecumseh index of risk for other populations was determined in a collaborative investigation of data collected in longitudinal epidemiologic studies in Baltimore, Boston, Framingham, Louisiana, Staveley, and Tucson. The extent to which the risk model fitted these data sets was assessed by comparing predicted (or expected) onsets of COPD in each population with observations made in each study. The predictors of COPD identified in Tecumseh were shown to be the most important risk factors in the other populations as well. The goodness-of-fit of the index was satisfactory overall. In all populations, a high risk score was associated with an increased incidence of COPD, thus confirming the predictive ability of the risk index. The Tecumseh index of risk provides a practical method for developing a risk profile from answers to standard questions and simple tests of lung function. Risks are greatest for heavy cigarette smokers with reduced lung function, lower in smokers who stop smoking or reduce their cigarette consumption, and lowest of all in nonsmokers with above average lung function.(ABSTRACT TRUNCATED AT 250 WORDS)
Adult↗
Assessment of air vs helium-oxygen flow-volume curves as an epidemiologic screening test.
Air and helium-oxygen maximum expiratory flow-volume curves were employed in an epidemiologic field study to assess the utility of density dependence as a screening test. Of 1,584 subjects tested, only 54.1 percent were able to perform the test with vital capacities for the two gases that agreed to within 5 percent. Subjects unable to perform the test properly tended to be older, with a greater prevalence of ventilatory function abnormalities and respiratory problems, than those who could perform the test. There was poor concordance between density dependence, or lack thereof, and standard ventilatory function measurements or evidence of respiratory disease. Under field survey conditions, the test of density dependence did not appear to be a useful screening tool.
Adolescent↗
A clinical trial of efficacy of antiproteolytic therapy: can it be done?
Explore the source record for details and available documents.
Clinical Trials as Topic↗
The natural history of air-flow obstruction in PiZ emphysema. Report of an NHLBI workshop.
Explore the source record for details and available documents.
Adult↗
Changes in the normal maximal expiratory flow-volume curve with growth and aging.
On the basis of their answers to a self-administered questionnaire, 697 nonsmoking healthy subjects were chosen from a randomly selected sample representative of the white non-Mexican-American population of Tucson, Arizona, enrolled in a longitudinal study of respiratory health. For each subject, the first satisfactory set of flow-volume data obtained during the first 3 consecutive surveys was selected for analysis. For forced vital capacity (FVC) and forced expiratory volume in one second (FEV1), the single best value for each subject was selected. Other flow-volume measurements were derived from the single test with the best sum FEV, plus FVC. These data were used to derive improved prediction equations for each sex by age group for 5 spirometric and flow-volume variables. The resulting predicted values demonstrate the effects of development, maturation, and senescence on ventilatory function. "Normal" limits are proposed that take into consideration the between-subject variability and non-Gaussian distribution of the various measurements.
Adolescent↗
A descriptive analysis of the growth and decline of the FVC and FEV1.
Using data obtained during the first four complete surveys of a general population sample (2,435 spirometric studies on 916 different asymptomatic nonsmoking subjects), we have derived mathematically continuous equations designed to describe the stages of growth, maturation, and subsequent decline in the forced expiratory volume in one second (FEV1) and the forced vital capacity (FVC). With this type of analysis, there appears to be a period from late childhood through adolescence in which maturation significantly increases FVC and FEV1 independent of growth, and a stage from late adolescence to the early or mid-30s in which there is relatively little change in these measurements. Progressive decline in FVC and FEV1 may not actually begin until the mid-30s. The mathematical formulae presented here were derived in a manner intended to describe biologic events and are not intended for use as prediction equations. The FEV1/FVC ratio appeared to be primarily a function of the FVC itself in young subjects. After the age of 33 years, FEV1/FVC also decreased with age, independent of the size of the FVC.
Adolescent↗
Interactions of smoking and immunologic factors in relation to airways obstruction.
The relationships of smoking, allergy skin test reactivity, and serum IgE to ventilatory function have been analyzed in 1,182 subjects from a general population sample. The study group consisted of subjects aged 35 or more who deny previous lung surgery, old tuberculosis, or a current diagnosis of heart disease in the absence of chronic bronchitis or emphysema. Impairment of the forced expiratory volume in one second (FEV1) shows a definite relationship to total serum IgE. However, this relationship is significant only for a low FEV1 which is accompanied by symptoms suggesting asthmatic or a chronic bronchitis type disease. Allergy skin test reactivity to a battery of common aeroallergens shows no overall relationship to FEV1. However, after accounting for total serum IgE, positive allergy skin tests tend to be associated with high rather than low FEV1 values. The findings suggest that some type of IgE which is not specific for aeroallergens but which is associated with smoking, may be important in the pathogenesis of the "chronic asthmatic bronchitis" syndrome.
Adult↗