Cases of alleged asbestos-related disease: a radiologic re-evaluation.

Chest radiographs were re-evaluated from 439 active and retired tireworkers previously designated as having a condition consistent with an asbestiform mineral exposure. The review was performed in an independent manner by three board-certified radiologists according to guidelines from an international classification system. The percentage of cases with abnormalities consistent with an asbestiform mineral exposure found separately by the three radiologists was 3.7, 3.0, and 2.7%. Application of an algorithm to form a consensus evaluation indicated that approximately 3.6% (16) of the subjects evaluated may have a condition consistent with an asbestos exposure. A more detailed review, however, revealed that only 11 workers, or 2.5% of the total, would have a reasonable likelihood of having such a condition. Most cases were normal and the majority of abnormalities present on the radiographs evaluated were nonoccupational in origin. Prevalent conditions identified included healed tuberculosis, histoplasmosis, emphysema, discoid atelectasis, effusions, healed rib fractures, scarring due to infection or old inflammatory disease, possible cancer, miscellaneous nonspecific linear markings consistent with cigarette smoking and aging, and heart and vascular system diseases--the latter evidenced by an abnormally large number of subjects with healed coronary artery bypass surgery and pacemaker implants. In summary, the best estimate from this study indicates that possibly 16 (3.6%), but more realistically 11 (2.5%), of the 439 tireworkers evaluated may have a condition consistent with exposure to an asbestiform mineral. This represents a 40-fold difference between the re-evaluation results and the original survey work.

Pulmonary arterial hypertension as a manifestation of lupus erythematosus.

We present five patients with systemic lupus erythematosus (SLE) who developed pulmonary arterial hypertension and cor pulmonale in the course of their disease. The clinical features, as well as, the radiological manifestations of this rare manifestation of SLE are discussed. A vasculitic process is the most likely cause of this complication. Therapy is ineffective and the prognosis is poor.

The morbidity and mortality of vermiculite miners and millers exposed to tremolite-actinolite: Part III. Radiographic findings.

A study was conducted to estimate the exposure-response relationship for tremolite-actinolite fiber exposure and radiographic findings among 184 men employed at a Montana vermiculite mine and mill. Workers were included if they had been employed during 1975-1982 and had achieved at least 5 years tenure at the Montana site. Past fiber exposure was associated with an increased prevalence of parenchymal and pleural radiographic abnormalities. Smoking was not significantly related to the prevalence of small opacities. However, the number of workers who had never smoked was small, and this prevented measurement of the smoking effect. Under control for smoking and age, the prevalence of small opacities was significantly greater for vermiculite workers with greater than 100 fiber/cc-years exposure than for comparison groups (cement workers, blue collar workers, and coal miners) who had no known occupational fiber exposure. A logistic model predicted an increase of 1.3% in the odds ratio for small opacities at an additional exposure of 5 fiber-years.

Study of chest radiographs and pulmonary ventilatory function in perlite workers.

A review of chest films from 152 workers who had been employed five or more years in perlite mining or processing showed none with small opacities of profusion 1/0 or higher. There were 14 films with doubtful changes (0/1), but these showed no correlation with type or duration of employment. Pulmonary function was measured in 122 current employees from the same plants. Multiple regression analysis showed no significant association between years of employment in perlite and either forced vital capacity (FVC) or forced expiratory volume (FEV1). There was a significant association between pack-years of cigarettes and both measurements. In 66 workers tested in 1975 and again in 1983, there was an average annual decrease in FVC of 32 mL, with 26 mL predicted by the Knudson formula, which is based on nonsmokers. The average annual decrease in FEV1 was 24 mL with 26 mL predicted. Comparison of groups with differing smoking patterns showed that the decreases in both FVC and FEV1 were associated with smoking. The 28 men who had added four or more pack-years in the interval between tests showed decreases in FVC and FEV1 of 44 mL/year and 31 mL/year, respectively, with 26 mL/year predicted for both groups. Those with less than four added pack-years (which included 26 nonsmokers) had decreases in FVC and FEV1 of 23 mL/year and 19 mL/year with 26 mL/year and 27 mL/year predicted.

Subpleural fat pads in patients exposed to asbestos: distinction from non-calcified pleural plaques.

Thirty patients with known asbestos dust exposure were studied because of uncertainty as to whether or not the pleural changes observed on the radiographs were due to plaques or subpleural fat. The CT scans confirmed that the changes were due to subpleural fat in 14 cases (48%). Characteristic subpleural fat shadows on radiographs and CT scans are described, and the importance of differentiating fat from plaques for medico-legal reasons is emphasized.

A 26-year radiographic follow-up of workers in a diatomite mine and mill.

Chest roentgenograms of 473 employees of a California diatomite plant were reviewed as part of periodic reevaluation of the efficacy of the dust control program. The plant's processing of diatomite included flux-calcination, which provided opportunities for exposure to cristobalite. The films examined were those of workers with at least five years of service. Only 11 films were interpreted as showing changes consistent with pneumoconiosis, i.e., small opacities of profusion categorized as 1/1 or greater. Only six were classified as 1/2 or more. All who developed categories 1/1 or higher during their employment had more than 25 years of service. No large opacities were reported. The low prevalence of abnormalities and the absence of definite pneumoconiosis in employees with fewer than 25 years of service was in striking contrast with findings in 1953. At that time more than 25% of those with five or more years of employment had roentgenographic evidence of pneumoconiosis and over 10% had confluent changes producing large opacities.

The detection of thoracic abnormalities using posterior-anterior (PA) vs PA and oblique roentgenograms.

A reading trial was conducted as part of the 1978 Bay Area Asbestos Screening Project to evaluate the utility of adding oblique-view roentgenograms to standard posterior-anterior (PA) views. Chest films from a sample of 555 workers with histories of long-term asbestos exposure were read twice as PA and twice as PA + oblique sets, providing a basis for assessing reliability through intrareader, interreader, and intermethod agreement. The ancillary use of oblique view films resulted in higher rates of detection of asbestos-related abnormalities than with PA films alone, but the increased rates were gained at the expense of reliability in the interpretation process. Depending on the source of this unreliability, which requires further study, different remedial actions might be indicated. A reader's lack of experience could indicate the need for additional training, the use of several readers, an average over several reader judgements, or the development of standards for evaluating obliques. If, on the other hand, no way is found to reduce the unreliability, the use of oblique films in routine screening programs ought to be discouraged on the basis of measurement theory, since reliability is a prerequisite to validity.

Calcified interlobar pleural plaques: visceral pleural involvement due to asbestos.

Visceral pleural involvement, seen as interlobar thickening and bilateral calcified plaques in the major interlobar fissures, was observed as a result of exposure to asbestos dust. This is in contrast to the parietal pleural involvement seen in most cases.

Efficacy and tolerance of ceruletide in radiography of the small intestine.

In a study of 30 patients, the intramuscular injection of ceruletide (0.3 microgram/kg) was safe and effective and resulted in a substantial decrease in the transit time required for the passage of barium to the ileocecal area. The median intestinal transit time following injection of ceruletide was 15 minutes as comapred to 80 minutes following a saline placebo. Adverse reactions were minimal and self-limiting.

Respiratory effects of exposure to dust in taconite mining and processing.

Taconite is a low-grade iron ore consisting of iron, quartz, and numerous silicates. Taconite from the eastern tip of the Mesabi Iron Range contains the amphibole silicate cummingtonite-grunerite, which is a mineral relative of amosite asbestos. In the present study, data were collected from 249 men with 20 or more years of exposure to taconite dust and 86 men without history of intimate exposure to taconite dust. Bronchitic symptoms and impairment of expiratory flow correlated significantly with history of cigarette smoking, but not with exposure to dust. Chest radiographs revealed three cases of possible silicosis. No case of definite interstitial fibrosis, ill-defined diaphragm, pleural calcification, or mesothelioma was found. We conclude that (1) cigarette smoking is significantly correlated with bronchitic symptoms and impairment of expiratory flow; (2) taconite workers are at risk of silicosis; (3) if dust containing cummingtonite-grunerite has biologic activity comparable to that of dust from asbestos, it is not evident after 20 years of low-level exposure.

Cholecystokinetic cholecystography: comparison of the effect of intramuscular ceruletide to a fatty meal.

A comparison study of 80 patients using either intramuscular ceruletide or a fatty meal to contract the gallbladder after oral cholecystography is described. The maximum mean percentage reduction of the gallbladder area was significantly greater with ceruletide (59%) compared to a fatty meal (29%). At all time intervals, a 40% or more reduction in gallbladder area occurred in a higher percentage of patients receiving ceruletide, with improvement in cystic and/or common duct visualization occurring at an earlier time than with a fatty meal. There were no adverse effects after gallbladder contraction when large or small calculi were present.

Bilateral pleural thickening: a manifestation of asbestos dust exposure.

Bilateral pleural thickening in a relatively asymptomatic patient without evidence of pulmonary disease is frequently a manifestation of asbestos dust exposure, particularly when it is localized or in the form of a noncalcified pleural plaque. Bilateral pleural thickening will be discovered with increasing frequency if specifically searched for on every radiograph. This radiographic finding is suggested as a more realistic indication of asbestos dust exposure, particularly when correlated with a complete occupational history.

Cholecystokinetic cholecystography: efficacy and tolerance studies of ceruletide.

The effect of intravenous and intramuscular administration of ceruletide on gallbladder contraction was investigated in 67 normal volunteers and patients. Of the 45 normal volunteers, 33 received the drug intravenously and 12 intramuscularly in graded ascending doses. By either means of injection, ceruletide produced a substantial contraction of the gallbladder with a measurable reduction in gallbladder area. Based on findings in these groups, the 22 patients requiring oral cholecystography for clinical evaluation received 0.3 microgram/kg intramuscularly. The intramuscular administration of synthetic ceruletide after oral cholecystography, in a dose of 0.o microgram/kg, afforded a safe and effective means of gallbladder contraction, with resultant cystic and common bile duct visualization. Side effects occurred less frequently when the drug was administered intramuscularly and were minimal and self-limiting. Peak contraction (40% or greater reduction in size) occurred as early as 5-15 min after after intramuscular injection and in most instances within 30 min.

Double-blind comparison of meglumine lodoxamate (Cholovue) and meglumine iodipamide (Cholografin).

A double-blind comparison of two intravenous cholangiocholecystographic agents of similar molecular structure, meglumine iodoxamate and meglumine iodipamide, was carried out in 90 patients. Each produced a comparably high percentage of satisfactory examinations. A similar pattern of excretion speed and intensity was noted for each, though meglumine iodoxamate appeared to be slightly more effective in patients with elevated serum bilirubin. Less evidence of hepatic toxicity and fewer and less serious adverse side effects were observed in patients given the newer agent, meglumine iodoxamate.

Cholecystokinetic cholecystography: efficacy and tolerance study of sincalide.

The intravenous administration of sincalide, the C-terminal octapeptide fragment of cholecystokinin, affords safe and effective means for gallbladder contraction with resultant cystic and common bile duct visualization. Intravenous sincalide circumvents the problem of unpredictability of response of the gallbladder to a fatty meal and variability in the rate of release of endogenous cholecystokinin. Peak gallbladder contraction occurs earlier than with a fatty meal.

Intercostal pulmonary hernia.

In five cases of intercostal pulmonary hernia, the hernia occurred following blunt chest trauma in two cases, after tube thoracostomy drainage in two, and following rib resection in one. Surgical repair was accomplished in three cases with good results, while in the remaining two the hernia underwent spontaneous regression.