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Biomedical subjects

B Burrows

Publications and source records attributed to B Burrows.

At least 73 records · Page 4Linked to original sources
PubMed1985

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↗
PubMed1985

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↗
PubMed1985

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↗
PubMed1984

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↗
PubMed1984

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↗
PubMed1984

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↗
PubMed1984

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↗
PubMed1983

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↗
PubMed1983

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↗
PubMed1983

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↗
PubMed1982

The relationship of serum immunoglobulin E, allergy skin tests, and smoking to respiratory disorders.

In this study of a general population sample in Tucson, Ariz., smokers showed higher levels of serum IgE despite having a lower rate of allergy skin-test reactivity to common aeroallergens than nonsmokers. The prevalence of rhinitis was closely related to the level of serum IgE in atopic subjects regardless of smoking habits. In nonatopic smokers, elevated IgE levels were not associated with high rhinitis rates. However, high IgE levels in nonatopic smokers were related to increased rates of diagnosed asthma, wheeze, and chronic cough and/or sputum (C/S). These relationships were especially striking in subjects over the age of 54. In older nonatopic smokers, reported prevalences of "chronic bronchitis" and of functional impairment also increased in relation to the level of serum IgE. Reduced ventilatory function showed this relationship to IgE only when accompanied by C/S. It is suggested that the excess IgE related to smoking is qualitatively different than that found in subjects reacting to aeroallergens, is not important in the pathogenesis of upper respiratory tract disease, but may play a role in the development of some lower respiratory tract disorders.

Adolescent↗
PubMed1982

Significance of intraindividual changes in maximum expiratory flow volume and peak expiratory flow measurements.

To examine criteria to assess significant changes of measurements derived from the forced expiratory vital capacity (FVC), and to examine changes in the peak expiratory flow (PEF) maneuvers, ten subjects were tested on approximately 30 occasions. Since mini Wright peak flow meters are increasingly used for clinical and research purposes, peak flow intraindividual variability and relations to FVC peak flow were examined, each set of tests consisting of five FVC maneuvers and one peak flow. Measurements on a pneumotachograph included FVC, (FEV1), maximum mid-expiratory flow (MMF or FEF25-75%), and instantaneous maximum expiratory flow after 50 and 75 percent expiration of the FVC. PEF measurements were derived using the mini Wright peak flow meter and the pneumotachograph. The coefficients of variation for the FVC measurements were greatest for maximum expiratory flow measurements and least for the FVC and FEV1. Maximum values from each set of tests reduced the variability. From these values, criteria and estimates were derived to evaluate significant intraindividual change. The PEF measurements were evaluated also to determine intraindividual changes. The coefficients of variation were only 2 percent to 14 percent. The peak flows obtained were shown to correlate well with the PVC peak flow.

Adult↗
PubMed1981

Distribution of IgE in a community population sample: correlations with age, sex, and allergen skin test reactivity.

The distribution of total serum IgE determined by the paper radioimmunosorbent test (PRIST) is examined in a large random stratified community population. Prior to logarithmic conversion the distribution of this immunoglobulin is not normal, with almost 40% of values below 20 IU/ml. A normal distribution occurs following such conversion, with a geometric mean value of 32.1 IU/ml. Both age and sex, in addition to atopic status, relate to IgE level. In both sexes highest levels occur among 6- to 14-year-olds, and males have higher levels than females at any given age. Women over age 75 yr have the lowest levels (geometric mean 9.2 IU/ml). Subjects with positive skin test results have several times the concentration of IgE as their nonatopic counterparts.

Adolescent↗