PubMed Health⌕ Search

Biomedical subjects

M S Tockman

Publications and source records attributed to M S Tockman.

At least 55 records · Page 3Linked to original sources
PubMed1988

Sensitive and specific monoclonal antibody recognition of human lung cancer antigen on preserved sputum cells: a new approach to early lung cancer detection.

Murine monoclonal antibodies (Mabs) to a glycolipid antigen of small-cell (SCC) and a protein antigen of non-small-cell lung cancer (NSCC) were applied to preserved sputum specimens from individuals who participated in The Johns Hopkins Lung Project (JHLP). In that study, undertaken in 1973 to evaluate the efficacy of sputum cytology screening, half of the high-risk participants (5,226 men, greater than or equal to 45 years of age, currently smoking greater than or equal to 1 pack of cigarettes per day) were randomly assigned to produce specimens for cytopathological analysis. During regular screenings over the next 5 to 8 years, 626 (12%) showed moderate (or greater) atypia. Sixty-nine of these (26 who progressed to cancer, 43 who did not) were randomly selected for a blinded improved Mab immunostaining protocol in the present study. Satisfactory specimens with morphologic atypia immunostained positively in 14 of the 22 patients who eventually progressed to cancer (sensitivity 64%), and were nonreactive in 35 of the 40 patients who did not progress to lung cancer (specificity 88%). Review of the true positive specimens (14/22 atypias) showed that they were collected 24 months in advance of diagnosis. In contrast, the 8/22 false negative atypias (failure to stain) showed that they were collected for an average of 57 months preceding the diagnosis of cancer. Subsequent specimens (average, 26 months before cancer) from participants who were originally considered "false negative" did stain positively improving sensitivity to 91% among specimens collected for an average of 2 years in advance of the clinical appearance of lung cancer. Specificity remained at 88%. Recognition of neoplastic antigen expression 2 years in advance of clinical cancer may be a valuable intermediate end point in studies of lung cancer prevention, detection, and therapy.

Aged↗
PubMed1988

Smoking, leukocyte count, and ventilatory lung function in working men.

Results of a cross-sectional study of ventilatory lung function (VLF) in a group of 307 working men showed that the leukocyte count in peripheral blood is more closely associated with the relative position (percentile) of a person in the frequency distribution of VLF than is smoking intensity. Leukocyte count is significantly (and inversely) correlated with VLF in nonsmokers as well as in smokers. A multiple regression analysis indicated that, after accounting for the effect of height and age, white blood cell (WBC) count explains more of the VLF variance than many other health determinants. Moreover, WBC count is the only variable, apart from height and age, that contributes significantly to the regression. Current smokers with elevated leukocyte count in peripheral blood may constitute a defined high-risk group because they demonstrate more negative regression age coefficients when compared with smokers without elevated WBC or with nonsmokers. Mechanisms that may explain these findings are discussed.

Adult↗
PubMed1987

Airways obstruction and the risk for lung cancer.

The presence of airways obstruction identify in middle-aged male smokers at increased risk for lung cancer. This hypothesis was tested in a sample of patients with moderate to severe obstruction from the Intermittent Positive Pressure Breathing Trial and a sample of patients with no obstruction to moderate obstruction from the Johns Hopkins Lung Project, all of whom were followed for the development of lung cancer. On follow-up, the risk of developing lung cancer was found to be associated with entry values for age, smoking, and ventilatory status by linear, proportional hazard, and log-linear adjustment techniques. Among cigarette smokers, the presence of airways obstruction was more of an indicator for the subsequent development of lung cancer than was age or the level of smoking. The risk for lung cancer also increased in proportion to the degree of airways obstruction. These data suggest that smokers with ventilatory obstruction are at greater risk for lung cancer than are smokers without obstruction.

Age Factors↗
PubMed1986

Sputum cytopathology: use and potential in monitoring the workplace environment by screening for biological effects of exposure.

Sputum cytopathologic monitoring detects squamous cell lung cancers at an extremely early stage (x-ray negative). It holds further potential for preventing disease by detecting epithelial alterations which reflect environmental hazards. The addition of sputum cytology screening to screening by chest x-ray film does not significantly reduce mortality from all types of lung cancer, but preliminary analysis of Johns Hopkins Lung Project data suggests that mortality from squamous cell carcinoma is reduced. Quantitative automated cytopathology systems and biochemical/immunological cell markers enhance understanding of these precursors and offer great promise for increasing capacity, accuracy, and usefulness in cytopathology screening of workers. Cytological specimens collected over years of screening workers considered at risk may be important to eventually understanding development and prevention of major occupational diseases.

Carcinoma, Squamous Cell↗
PubMed1985

Familial aggregation in chronic obstructive pulmonary disease: use of the loglinear model to analyze intermediate environmental and genetic risk factors.

To examine the contribution of environmental and genetic risk factors to familial aggregation in chronic obstructive pulmonary disease (COPD), 325 first-degree (1d) relatives and 56 spouses of 150 COPD patients were compared with 222 1d relatives and 49 spouses of 107 nonpulmonary patient controls for the prevalence of two clinical outcomes: 1) airways obstruction (AO; 1-sec forced expiratory volume less than 68% of forced vital capacity) and 2) chronic bronchitis (CB; cough and sputum for 3+ months per year for 2+ years). The loglinear model was used to study direct and indirect (ie, those mediated by other risk factors) components of familial aggregation. Three risk factors were found to be independently associated with CB and/or AO: alpha 1-antitrypsin deficiency (PiZ allele), personal cigarette smoking, and parental cigarette smoking. Because 1d relatives of COPD patients were more likely to have a PiZ allele, be heavy smokers (1+ packs per day), and be exposed to parental smoking than 1d relatives of controls, these three factors also constitute indirect components of familial aggregation. However, after controlling for the three factors, 1d relatives of COPD patients were more likely to have AO and CB than 1d relatives of controls (direct component). This direct component might have a genetic basis, because no such association was found when spouses instead of 1d relatives were compared. Thus, both shared environmental factors (personal and passive smoking) and shared genetic factors (alpha 1-antitrypsin and a possible direct genetic component) contribute to familial aggregation in COPD. The loglinear model provides a useful tool for analyzing familial aggregation in diseases of multifactorial etiology.

Biometry↗
PubMed1985

Effects of pulmonary function on mortality.

Survivorship data from a 24 year longitudinal study of 874 male volunteers in the Baltimore Longitudinal Study of Aging were used to assess the role of pulmonary function on total mortality. Even when age and smoking were considered, the ratio of forced expiratory volume in 1 sec to its predicted value was significantly associated with mortality from all causes. Individuals with poorer pulmonary function showed greater mortality during the follow-up period of this study. This relationship was also seen among never smokers in this sample, further supporting the hypothesis that impaired pulmonary function is itself a predictor of total mortality and may contribute to a number of disease processes.

Adolescent↗
PubMed1985

Pulmonary function and respiratory symptoms in polyvinylchloride fabrication workers.

We performed preshift and postshift spirometry and administered a standardized respiratory symptoms questionnaire to 174 white males currently employed in polyvinylchloride (PVC) fabrication to examine the acute and chronic respiratory effects of work exposure. Although there were no significant differences between the in-plant comparison group and any department with potential exposures, there was evidence for respiratory effects in the combined group of comparison and exposed workers. In the combined group, duration of employment was significantly associated with decrements in adjusted cross-shift ratio of forced expiratory volume in one second to forced vital capacity (FEV1/FVC), preshift FEV1/FVC, and prevalence of chronic cough and chronic phlegm. In nonsmokers, the prevalences of chronic wheeze and chest tightness were high (36.0 and 50.5%, respectively). The age-adjusted prevalence of chronic wheeze in nonsmokers was also elevated 3.54-fold when compared with that in a community study in the literature. We conclude that the cross-sectional design and in-plant comparison group may mask the effects of exposures on the entire plant population, and that employment in this plant is associated with patterns of obstructive air-flow limitation and respiratory symptoms consistent with exposure to pulmonary irritants. These results suggest that possible agents of pulmonary effects in PVC fabrication are not limited to vinyl chloride monomer, PVC dust, and PVC thermal degradation products.

Adult↗
PubMed1984

Collaborative study to assess risk of lung disease in Pi MZ phenotype subjects.

We studied 143 Pi MZ heterozygous (MZ) subjects from random populations that had been examined previously for alpha 1-antitrypsin phenotype. Each Pi MZ subject was closely matched with a Pi M control subject from the same population at each of 6 centers. An expanded National Heart, Lung and Blood Institute (NHLBI) respiratory symptom questionnaire was completed by each subject. Pulmonary function tests designed to detect established as well as early obstructive airway abnormalities were administered. Multivariate analysis of the variance of data from the questionnaire and pulmonary function tests corrected for age, race, sex, and smoking history showed no significant difference (p less than 0.05) between subjects of Pi MZ and Pi M phenotype. The size of the populations studied and number of observations made for each variable were sufficient to assure that small differences could be detected with 95% power. We conclude that MZ phenotype alone carries no greater risk of developing lung disease than M phenotype.

Adult↗
PubMed1984

Early lung cancer detection: results of the initial (prevalence) radiologic and cytologic screening in the Johns Hopkins study.

The Johns Hopkins Lung Project was designed to determine whether the addition of cytologic screening to the radiographic screening of high-risk volunteers could enhance the early detection of asymptomatic lung cancer and whether early therapeutic intervention in detected cases could significantly reduce the mortality from this disease. Male volunteers, 45 yr of age and older, who smoked at least 1 pack of cigarettes per day were recruited from the Baltimore metropolitan area. All of the 10,387 acceptable high-risk volunteers received annual chest radiographic screening. By random assignment, one half received cytologic examination of induced sputum in addition to the roentgenogram. This report describes the results of the initial screening. Compared with usual methods of clinical diagnosis, screening by both roentgenography and cytology identified a greater proportion of the lung cancer cases at an earlier stage. Screening by sputum cytology was found to improve the detection only of squamous cell carcinoma. In the dual-screen group, sputum cytology accounted for 28% of the detected cases, and resulted in 39% additional detection of lung cancer over that achieved by roentgenography. There was no corresponding decrease in prevalence. Lung cancers detected by cytology alone were found at very early stages. Although there has been an increase in average survival, much of this increase, if not all, may have resulted from lead-time and sampling bias.

Adenocarcinoma↗
PubMed1982

Lung cancer mortality in males screened by chest X-ray and cytologic sputum examination: a preliminary report.

Observations from the continuing JHLP lung cancer screening study provide no clear evidence that mass screening by chest X-ray and sputum cytology, plus prompt appropriate treatment, reduces mortality du to lung cancer. No reduction in lung cancer deaths is observed in the JHLP when compared with the number of lung cancer deaths expected from the experience of two unscreened male populations of the same age and smoking status serving as population studies. Possible reasons for the lack of demonstrable decrease in mortality, even though "early" cases have been detected, include: (1) an insufficient passage of time for slowly growing cancers to become apparent in the control group, (2) ineffective therapy, and (3) the multifocal nature of pulmonary neoplasms. Additional study will be required to provide a definitive answer regarding the benefit, if any, of lung cancer screening.

Aged↗
PubMed1982

Epidemiology in the workplace: the problem of misclassification.

Strategies for recognition and quantification of misclassification are presented. Misclassification occurs when a subject is placed in the wrong "exposure" or the wrong "outcome" category as a result of the failure of an index measurement to reflect exposure or disease accurately. Data from a Health Hazard Evaluation illustrate how misclassification may result in an unwarranted etiologic assumption. Data from a lung cancer screening program illustrate how misclassification may result in erroneous estimates of disease prevalence.

Adult↗
PubMed1981

Ventilation-perfusion lung scanning in patients detected by a screening program for early lung carcinoma.

Ventilation-perfusion (V-P) lung scans obtained in 114 patients in screening program for the early detection of lung cancer were reviewed, and abnormalities were correlated with radiographic and surgical findings. Eighty-seven patients eventually had a tissue diagnosis of carcinoma; 65 (75%) had a perfusion defect and 56 (67%) had a ventilation abnormality at the tumor site. Lobar or segmental perfusion abnormalities were present at the tumor site in two of 13 patients whose lung cancer could not be localized by chest radiographs. However, 12 of these 13 patients and 54% of those with radiographically visible lesions had perfusion abnormalities in other lung regions. Twenty-seven patients with suspected carcinoma who were subsequently proved to have benign lesions had V-P abnormalities similar to those in patients with lung cancer. Thus, no pattern of V-P abnormalities similar to those in patients with lung cancer. Thus, no pattern of V-P abnormalities allowed lung cancer in this screened population to be reliably distinguished from coexisting airway disease or non-malignant pulmonary masses. V-P lung studies have a limited role in the early detection of lung cancer.

Aged↗
PubMed1981

Respiratory effects on household exposures to tobacco smoke and gas cooking.

The records of 1,724 residents of Washington County, Maryland, who had participated in 2 studies of respiratory symptoms and ventilatory function were analyzed to evaluate the effects of exposures at home to tobacco smoke generated by other members of their households and to fumes from the use of gas as a cooking fuel. Currently smoking subjects showed the highest frequency of respiratory symptoms and impaired ventilatory function; former smokers showed a lower frequency of these findings; and persons who had never smoked had the lowest prevalence of abnormal respiratory findings. The presence of a smoker in the household other than the subject was not associated with the frequency of respiratory symptoms, and only suggestively associated with evidence of impaired ventilatory function. The use of gas for cooking was related to an increased frequency of respiratory symptoms and impaired ventilatory function among men, being most marked among men who had never smoked. There was not evidence that cooking with gas was harmful to women.

Adult↗