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Biomedical subjects

M D Lebowitz

Publications and source records attributed to M D Lebowitz.

At least 163 records · Page 9Linked to original sources
PubMed1977

Quantitative relationships between cigarette smoking and chronic productive cough.

A close relationship between chronic productive cough and cigarette smoking was confirmed in an epidemiological study of airways obstructive disease in Tucson. Pack-years of smoking was closely related to symptom frequency and no threshold effect was noted. This relationship was affected by age and a history of childhood respiratory disease, but not by atopy. Among present smokers males and females did not differ significantly in their smoking habit specific rates of chronic productive cough, but males appeared to lose their symptoms less regularly than females when they quit smoking after many pack-years of cigarette use. When the relationship of smoking to chronic productive cough was removed, smoking was not significantly related to other aspects of 'chronic nonspecific respiratory disease' in this analysis.

Adolescent↗
PubMed1977

Smoking habits and changes in smoking habits as they relate to chronic conditions and respiratory symptoms.

The relation of smoking to chronic lung disease has been documented in several studies. Several conclusions have been drawn about the type of smoking associated withdisease, including inhalation, filter tip use, and reduction in smoking. These factors were examined in a community epidemiologic study of chronic obstructive lung diseases. It was found that the community population exhibited greater filter tip use and higher rates of exsmoking than often seen elsewhere. Smoking habits and the changes in smoking habits over time were related to physician-diagnosed emphysema and/or chronic bronchitis, but not asthma. Some relation was seen also with present heart trouble. There was dose-relationship to pack-years of smoking in both present and ex-smokers. There were more ex-smokers among males. Most male ex-smokers quit due to symptoms. Ex-smokers were found to have high rates of diagnosed disease but reduced rates of symptoms. The incidence of diagnosed disease was found to be associated with smoking, both in intensity and duration. Changes in smoking over time were found to be correlated with symptomatology.

Adolescent↗
PubMed1977

The relationship of acute respiratory illness history to the prevalence and incidence of obstructive lung disorders.

Several studies have suggested that acute respiratory illnesses (ARI) may be precursors to chronic obstructive lung diseases, as well as being exacerbations of such diseases. The relationship of retrospective and prospective data on ARI to the prevalence and incidence of obstructive lung disorders has been examined in the community epidemiologic study of obstructive diseases a longitudinal study in Tucson. It has been determined that both the previous and subsequent history of ARI are significantly associated with the prevalence and incidence of airways obstructive diseases, those diagnosed by physicians and those inferred by symptoms. Lung function impairment also appears to be associated with such illnesses. This study implicates ARI as one of the major factors associated with the etiology as well as the natural history of chronic obstructive lung disease.

Acute Disease↗
PubMed1977

Quantitative relationships between cigarette smoking and ventilatory function.

In this study of a general population sample, highly significant quantitative relationships were noted between pack-years of smoking and functional impairment. Subjects with chronic productive cough showed steeper declines in the forced expired volume in 1 sec and forced expiratory flow after exhalation of 75 per cent of the forced vital capacity (Vmax 25), but a definite inverse relationship between ventilatory function and pack-years was demonstrated even among subjects who denied any cough or sputum production. Current smoking showed no relationship to 1-sec forced expiratory volume or Vmax 25 when total pack-years were taken into account. Age appeared to be an important independent determinant of per cent predicted values only in regard to the Vmax 25 in symptomatic nonsmoking women. A history of childhood respiratory trouble was associated with a lower ventilatory function regardless of smoking habits, and for this reason such subjects have been deleted from detailed analyses of dose-effect relationships. Allergy skin test reactivity in young to middle-aged adults showed a significant additive effect to pack-years as a determinant of forced expiratory flow toward the end of the forced vital capacity, but the effect was noted only among present smokers.

Age Factors↗
PubMed1977

The closing volume test: evaluation of nitrogen and bolus methods in a random population.

The closing volume test, using helium bolus and nitrogen washout techniques simultaneously, was evaluated in more than 1,900 persons randomly selected as representative of the white population of Tucson, Arizona. Normal values were based on data obtained from those totally asymptomatic persons who had never smoked cigarettes. In the remaining population, the slope of Phase III appeared to be more sensitive than any other measurement in detecting abnormalities, but all measurements taken in conjunction were superior to any single parameter. Closing volumes measured by the bolus method were systematically greater than those obtained by resident nitrogen technique in normal subjects and were slightly more sensitive in detecting abnormalities in other population subgroups. Nevertheless, the single-breath test was of only limited value in distinguishing asymptomatic smokers from nonsmokers. Parameters used in conjunction revealed abnormalities in 36% of symptomatic subjects, many of whom already had physician-confirmed obstructive pulmonary disease. Our data suggest that, when applied to a randomly selected population, abnormalities in the closing volume test occur in only a very small proportion of persons in whom a respiratory disorder would not otherwise be suspected or already diagnosed.

Adolescent↗
PubMed1977

The relationship of childhood respiratory illness to adult obstructive airway disease.

This study of a general population sample reveals close relationships between histories of childhood respiratory disorders and pevalences of symptoms, obstructive airway diseases, and ventilatory impairment in 2,626 adults more than 20 years of age. Although a history of pediatric respiratory illness is associated with relatively mild impairment of ventilatory function in young adults, subjects with such a history shown an excessive decline in function with advancing years and with cigarette use. Because some of the data are retrospective and subject to the bias of preferential recall of childhood events, these observations cannot be regarded as definitive. However, present observations are compatible with the hypothesis that pediatric respiratory illness represents an important risk factor for the development of obstructive airway diseases in adult life. It is suggested that these childhood respiratory illnesses cause the adult lung to be unusually susceptible to the adverse effects of a variety of bronchial irritants and infectious agents.

Adolescent↗
PubMed1977

Lung function in infants and young children: functional residual capacity, tidal volume, and respiratory rats.

Functional residual capacity was measured by the closed-circuit, helium-equilibration method in 121 normal children 3 months to 6 years of age. Prediction equations for functional residual capacity for normal children of this age range are presented for the first time. This study demonstrates that some aspects of lung functiok can be studied relatively conveniently in young children.

Body Height↗
PubMed1976

The maximal expiratory flow-volume curve. Normal standards, variability, and effects of age.

From a randomly selected population representative of the white population of Tucson, Ariz., satisfactory flow-volume data were obtained for 3,115 persons. Data from the 746 subjects who were totally free of symptoms or history of cardiorespiratory disease and who had never smoked were used in determining "normal" prediction equations for spirometric parameters and maximal expiratory flows. The maximal expiratory flow-volume curve showed considerable intersubject variability, but little change in shape of the mean maximal expiratory flow-volume curve was seen with advancing age when the effects of disease, insult, or injury were excluded.

Adolescent↗
PubMed1976

Comparison of questionnaires: the BMRC and NHLI respiratory questionnaires and a new self-completion questionnaire.

Interviewer-administered National Heart and Lung Institute (NHLI) and British Medical Research Council (BMRC) respiratory questionnaires were compared with each other and with a self-administered questionnaire of our own design in 2,350 adults enrolled in a longitudinal community study. There was a basic 10% disagreement between responses to any 2 questionnaires for all questions that inquired about a perception of a complaint or a disease, but much less disagreement for more factual questions, such as those concerning smoking. Little effect was noted from minor variations in wording, order of questions, method of administration, inclusion of other questions, or time between questionnaires (as long as this interval was less than 1 month). For questions with similar wording, the BMRC and NHLI questionnaires yielded very similar results in terms of over-all prevalence of responses, relationships to answers on an independent questionnaire, and inter-relationships of positive responses. The new self-completion questionnaire used in this study detected more abnormalities and better delineated cough and phlegm "syndromes" than either the NHLI or the BMRC questionnaire, and we believe that self-administration was a very satisfactory technique in the type of population surveyed in this study.

Adult↗
PubMed1976

The maximal expiratory flow-volume curve: its use in the detection of ventilatory abnormalities in a population study.

Flow-volume and spirometric parameters obtained in a randomly selected population were examined with regard to their sensitivity in detecting abnormalities among persons who smoked and/or had respiratory symptoms. Data obtained from subjects who were totally free of cardiorespiratory symptoms and who had never smoked cigarettes were used to develop "normal" prediction equations. Using as normal limits the per cent of predicted value above which 95% of these "normal" subjects fell, maximal expiratory flow at 75% of the expired vital capacity (Vmax75) detected the greatest proportion of abnormalities in the remainder of the population. When examined according to age, however, Vmax75 was most sensitive in older subjects, whereas 1-sec forced expiratory volume was superior in younger subjects. There was a slight tendency for Vmax75 to be affected in subjects with reactive airway syndromes and for the 1-sec forced expiratory volume to be affected in heavy smokers or subjects with chronic productive cough. If one parameter was markedly abnormal, the entire flow-volume curve was likely to be affected, but concordance of the parameters examined was not complete. For the latter reason, considerable caution must be exercised in attempting to use multiple parameters in defining abnormality, unless one applies more stringent criteria for abnormality.

Adolescent↗
PubMed1976

Respiratory symptoms related to smoking habits of family adults.

A study of the effects of family smoking habits on the symptoms of other family members has shown that symptoms of household members, especially children, are related to smoking habits within the households but are not significantly so when symptoms in adults are controlled.

Adolescent↗
PubMed1976

Immediate skin-test reactivity in a general population sample.

To assess the prevalence and distribution of allergic skin-test reactions in a general population sample, allergy prick tests were applied to 3101 subjects older than 2 years of age. Test materials included allergens common to the Tucson environment, and subjects were randomly stratified by age, sex, and socioeconomic status. No difference in the prevalence of measurable reactions was found among male subjects versus female subjects. A definite age relation was apparent, however, with the peak prevalence of reactivity (more than 40%) occurring during the third decade, and falling rapidly past age 50. When present, reactions tended to be multiple, highly reproducible, and more frequent among those in the higher socioeconomic strata. The prick test was judged to be a useful tool for the assessment of atopy.

Age Factors↗
PubMed1976

Respiratory disorders and allergy skin-test reactions.

This study examines the relations of allergy skin-test reactivity, assessed by prick testing, to a variety of respiratory symptoms, findings, and diagnoses in a general population sample consisting of more than 3000 subjects. The independent and combined relations of skin-test reactivity and cigarette smoking are reported. Prevalences of asthma and allergic rhinitis are closely related to the severity of skin-test reactions; all of the 39 subjects with the largest skin-test reactions observed have had one or both of these conditions. A variety of other respiratory findings, not generally considered allergic in nature, are also related to skin-test reactivity, especially in children and in young to middle-aged adults. In subjects 15 to 54 years of age, an atopic predisposition, as manifested by reactions to allergy skin tests, appears to be associated with an increased susceptibility to the bronchoconstrictor effects of cigarette smoking and to recurrent chest infections. It is suggested that an atopic predisposition relatively early in life may be a risk factor for the later development of chronic obstructive lung diseases.

Adolescent↗