Pulmonary Clearance and the Function of Macrophages

Toxicity of a Quartz with Occluded Surfaces in a 90-Day Intratracheal Instillation Study in Rats

“…Thus, in order to deliver the same mass dose as well as the same dose of quartz, the reference quartz had to be supplemented with additional particulate material to produce a positive control mixture that contained 60% quartz. Fine titanium dioxide particles were selected because they represent particles that have been used and recognized for decades, in inhalation toxicology, as a negative control particle (Ferin et al, 1965;Ferin, 1994). In the previously conducted 28-day study (Creutzenberg et al, 2003), separate groups of rats were dosed with reference quartz (quartz DQ12 fine size) or a mixture of 71.25% reference quartz and 28.75% titanium dioxide.…”

Supplement

“…The number of free lung cells in the airways can be influenced by different inhaled agents, as has been demonstrated earlier (10,11,25,30,40,60). Certain aspects of the role of free lung cells, as well as their quantitation and regulation, was described by Brain (12).…”

Inhaled /sup 239/PuO/sub 2/ and/or total-body gamma radiation: Early mortality and morbidity in rats and dogs

“…Impaired clearance by gamma irradiation has been reported in results of experiments designed for that purpose (Ferin et ai., 1965;Rhoads et at., 1981;Sanders et al, 1983). Ferin et al (1965) showed that total-body X-ray exposure of only 300 R caused impaired clearance of silicon dioxide from the lungs of rats, but only if the rats were exposed 1 day or less before inhalation of the silicon dioxide. Rhoads et al (1981) reported decreased clearance of plutonium from the lungs of rats caused by 137Cs gamma irradiation, although the exposure conditions were quite different from those in the previous work, in that the rats were exposed to plutonium several months after gamma irradiation.'…”