strontium-radioisotopes and Lung-Diseases

Cigarette smoking can influence the pulmonary disposition of other inhaled materials in humans and laboratory animals. This study was undertaken to investigate the influence of cigarette smoke exposures of rats on the pulmonary clearance of inhaled, relatively insoluble radioactive tracer particles. Following 13 weeks of whole-body exposure to air or mainstream cigarette smoke for 6 hr/day, 5 days/week at concentrations of 0, 100, or 250 mg total particulate matter (TPM)/m3, rats were acutely exposed pernasally to 85Sr-labeled fused aluminosilicate (85Sr-FAP) tracer particles, then air or smoke exposures were resumed. A separate group of rats was exposed to the 85Sr-FAP then serially euthanized through 6 months after exposure to confirm the relative insolubility of the tracer particles. We observed decreased tracer particle clearance from the lungs that was smoke concentration-dependent. By 180 days after exposure to the tracer aerosol, about 14, 20, and 40% of the initial activity of tracer was present in control, 100 mg TPM/m3, and 250 mg TPM/m3 groups, respectively. Body weight gains were less in smoke-exposed rats than in controls. Smoke exposure produced lung lesions which included increased numbers of pigmented alveolar macrophages distributed throughout the parenchyma and focal collections of enlarged alveolar macrophages with concomitant alveolar epithelial hyperplasia and neutrophilic alveolitis. The severity of the lesions increased with smoke exposure duration and concentration to include interstitial aggregates of pigmented macrophages and interstitial fibrosis. Our data confirm previous findings that exposure to cigarette smoke decreases the ability of the lungs to clear inhaled materials. We further demonstrate an exposure-concentration related magnitude of effect, suggesting that the cigarette smoke-exposed rat constitutes a useful model for studies of the effects of cigarette smoke on the disposition of inhaled particles.

Topics: Administration, Oral; Animals; Body Weight; Female; Lung; Lung Diseases; Male; Rats; Rats, Inbred F344; Strontium; Strontium Radioisotopes; Time Factors; Tissue Distribution; Tobacco Smoke Pollution

Three cases of diffuse lung uptake of the bone scanning agent 99mTc diphosphonate, which appears to reflect metastatic pulmonary calcification, are described. Each patient had hypercalcemia and renal failure. Clinical features common to patients with this scan pattern were ascertained from a review of the literature. Renal failure was present in all, and the majority have had hypercalcemia. The bone scan may prove to be a valuable adjunct to the diagnosis of metastatic pulmonary calcification; this characteristic pattern should be more widely appreciated.

Topics: Adolescent; Adult; Aged; Bone and Bones; Calcinosis; Female; Humans; Lung Diseases; Male; Middle Aged; Radionuclide Imaging; Strontium Radioisotopes; Technetium

Topics: Bone and Bones; Calcinosis; Calcium; Diphosphates; Fluorides; Humans; Lung Diseases; Phosphoric Monoester Hydrolases; Pulmonary Fibrosis; Radioisotopes; Radionuclide Imaging; Strontium Radioisotopes; Technetium