Biomedical subjects

J T Lien

Publications and source records attributed to J T Lien.

14 recordsLinked to original sources

PubMed1995

Asbestos-related radiographic changes by ILO classification of 10 x 10 cm chest X-rays in a screening of the general population.

A sample of 1388 10 x 10 cm chest X-rays from a previous population screening of males aged 40+ years were reevaluated by use of the ILO classification. There were 1036 films of subjects from an industrialized town, and 352 from a rural community. The observed rates of parenchymal changes (profusion > or = 1/0) at the reevaluation were 1.3% in the urban community and 3.4% in the rural community. The corresponding figures for pleural changes were 5.0% and 0.6%, respectively. Based on additional questionnaire information on asbestos exposure, it was found that the radiographic changes were probably related to past asbestos exposure for 2.3% of the subjects from the urban community and 0.6% from the rural community. In cases of asbestos-related illnesses the mean time since first exposure to asbestos was 35.9 years, whereas the mean duration of the exposures was 11.4 years. The results seem to indicate that the ILO reassessment of the radiographs was more sensitive in detecting pleural changes than the previous clinical screening of both small and large films.

Adult↗

PubMed1993

Karyotypic changes in the preclinical and subsequent stages of malignant mesothelioma: a case report.

The karyotypic evolution was evaluated in cells from recurring pleural effusions in a patient previously exposed to asbestos. Pleural malignant mesothelioma (MM) was diagnosed 4 years after the first cytogenetic examination. The primary cytogenetic changes consisted of loss of chromosomes 1p,14,21, Y, both 22, and derivative chromosomes involving 1, 2, and 14. The modal chromosome number was 44. Sixty-seven percent of the cells had a normal karyotype. After 4 years of spontaneous remission, only 6% of the cells had a normal karyotype, 42% had the same karyotypic changes as found previously, whereas 52% had additional derivative chromosomes involving chromosomes 1, 3, 5, 7, 8, and 12, trisomy 7, 7p, and 11, and partial or whole monosomy 3, 8, and 9. The chromosomal changes are in agreement with the main findings in previous reports. The karyotype remained quite stable for 7 months in vitro. After 23 months in culture, all the cells were near-triploid. Cells established in culture were cytokeratin positive. All derivative and marker chromosomes identified in the cultured cells had previously been observed in direct preparations from the pleural effusions. We conclude that chromosomes 1, 14, 21, and 22 may be involved in the preclinical stage of development of asbestos-induced mesothelioma, whereas the later chromosomal changes may be related to progression of the tumor.

Aged↗

PubMed1992

Chest radiographs in subjects with asbestos-related abnormalities: comparison between ILO categorizations and clinical reading.

The findings of a previous chest X-ray screening, determined without using standardized criteria, were reassessed by means of the ILO classification. Of 470 radiographs that had been determined as showing asbestos-related changes, 430 were categorized according to the ILO Classification. Small opacities with profusion greater than or equal to 1/0 were described in 39 (52%) of 75 participants who, on the original clinical reading, had been determined as having lung fibrosis, and in 45 (12.7%) of 355 who were determined as having pleural changes only. When considering circumscribed pleural thickening at the chest wall or diaphragm, as categorized by the ILO Classification, such changes were present in 401 (93.7%) of 428 subjects with pleural changes as determined on the clinical reading. In addition to the improved sensitivity and specificity achieved, the ILO Classification also allows comparison with other studies. The most apparent disadvantage of the ILO system is that it cannot firmly separate the various types of asbestos-related pleural changes. The study revealed that the previous asbestos exposure of the case subjects had occurred in many different workplaces and occupations.

Adult↗

PubMed1987

Lung function and respiratory symptoms in subjects with asbestos-related disorders: a cross-sectional study.

The prevalence of respiratory symptoms and lung function impairment was studied in a sample of men from a population screening of asbestos-related disorders. When the rates were adjusted for age and smoking habits, 83 subjects with lung fibrosis had an increased prevalence of respiratory symptoms, in particular, phlegm when coughing and breathlessness grades 1-3. Among 200 subjects under 70 years of age who had pleural plaques only, a statistically significant increase was observed in the prevalence of breathlessness grade 1 compared to an external reference population. Among 98 asbestos-exposed subjects who had normal chest X-rays, there was an increase in the prevalence of breathlessness grade 2, cough during the day, and phlegm when coughing. There was a higher proportion of subjects with lung fibrosis who were below 80% of the predicted values for forced vital capacity (FVC) and forced expiratory volume in 1 second (FEV1) than in the other groups. There was also a higher proportion of subjects with pleural plaques only who were below 90% of the predicted value for FVC than in a group of 90 subjects without asbestos exposure. In accordance with previous studies, these results indicate that pleural plaques in asbestos workers may be of greater importance as a clinical feature than has been recognized in the past.

Adult↗

PubMed1986

Asbestos-related findings in chest radiographs of the male population of the county of Telemark, Norway--a cross-sectional study.

In order to investigate the prevalence of asbestos-related diseases, a cross-sectional population study was conducted among 28,216 men aged 40 years in nine municipalities of the county of Telemark, Norway. In a primary radiographic screening 10 X 10-cm chest radiographs were taken of 21,483 persons. In two independent readings of the radiographs, pleural changes were observed in 6.9 and 8.5% of the study subjects. Radiographic findings in the primary screening led to 1,431 subjects being selected for a reexamination. On the basis of occupational histories and 40 X 40-cm chest radiographs, it was concluded that 470 of these subjects (2.2% of the screened population) had radiographic changes consistent with an asbestos-related disorder. Among these, 86 had lung fibrosis (82 in combination with pleural plaques) and 384 had pleural plaques only. There were marked differences in the occurrence of asbestos-related disorders between the seven urban and two rural communities studied, and agreement was observed between the occurrence of such disorders and the degree and duration of the reported asbestos exposure. The study presents evidence that asbestos-related disorders may be more prevalent in the general male population than has been recognized earlier.

Adult↗

PubMed1986

Previous asbestos exposure and smoking habits in the county of Telemark, Norway--a cross-sectional population study.

A cross-sectional population study. Scand J Work Environ Health 12 (1986) 561-566. In order to study the number of persons previously exposed to asbestos in the general population, an investigation with a self-administered questionnaire and a screening with 10 X 10-cm chest radiographs was conducted among 28,216 men aged 40 years and over in nine municipalities in the county of Telemark, Norway. Among the 21,453 subjects who answered the questionnaire in the primary screening, 3,888 (18.1%) reported previous occupational exposure to asbestos. Of the exposed subjects 2,368 (61.4%) were less than 60 years of age, and 2,611 (69.9%) had been exposed for the first time after 1950. In regard to the degree of exposure, 77.7% considered their previous exposure to be light. Past and present smoking habits were recorded for all the subjects, and a high-risk group of 1,734 subjects with past exposure to asbestos and present smoking was identified. Approximately 270 incident cases of lung cancer can be expected among the 21,453 study subjects during the next 10 years, and it is estimated that about 110 of these cases will occur in the high-risk group with combined asbestos-cigarette exposure.

Adult↗

PubMed1986

A case-referent study of lung cancer, occupational exposures and smoking. II. Role of asbestos exposure.

In a hospital-based case-referent study of 176 incident lung cancer cases, ascertained during a five-year period from two county hospitals, the role of asbestos exposure and smoking has been studied. Information on asbestos exposure was obtained from personal interviews, and allocated to four exposure categories, according to the intensity and duration of the exposure. Twenty-five percent of the cases and 10% of the referents had been moderately to heavily exposed to asbestos during their working career. A statistically significant trend in risk ratio related to the degree of exposure was observed, with a more than fourfold risk among the heavily exposed. The strongest association was found between asbestos exposure and small cell carcinoma, and the weakest association between asbestos exposure and adenocarcinoma. Very high risk ratios were observed among asbestos-exposed subjects who were heavy smokers, and the interaction observed between asbestos and smoking conformed more closely to a multiplicative model than to an additive one. The results suggest that the observed association between lung cancer and occupational exposures in this study was, to a large extent, due to asbestos exposure. Information on such exposure was missing in 90% of the medical records of these patients.

Adult↗

PubMed1986

A case-referent study of lung cancer, occupational exposures and smoking. I. Comparison of title-based and exposure-based occupational information.

The role of occupational exposures and smoking in the development of lung cancer has been studied among 176 male incident lung cancer cases and 176 referents admitted to two county hospitals in southeast Norway during 1979-1983. After the allocation of all occupational titles in the Nordic Classification of Occupations into three exposure groups according to potential exposure to respiratory carcinogens and other contaminants, each subject was classified according to exposure status of main occupation and number of years in each exposure category. An excess risk of lung cancer was observed both among those in possibly exposed occupations and among those definitely exposed. A more than threefold excess risk was observed among subjects with more than 30 years in exposed occupations. Exposure to 22 agents/processes was further assessed by a separate questionnaire and estimated simultaneously in a logistic regression model. Elevated risks were associated with exposure to asbestos and several other agents/processes, which largely correlated to each other. Smoking was strongly associated with all histological subtypes of lung cancer, while for occupational exposures the risk ratio was highest for small cell carcinoma and lowest for adenocarcinoma. Very high risk ratios for lung cancer were observed among heavy smokers in exposed occupations.

Adult↗

PubMed1985