Fig. 2

Photomicrographs of representative fields of BAL Giemsa stained slides from each time period and 2.5% treatment groups. All photomicrographs taken at 400X. Bar on each image represents 10 m. a. Control group for talc instillation studies (saline plus surface active material instillation). Mostly alveolar macrophages were observed in these slides. b. One day after 2.5% talc particle instillation, uptake of varying sized birefringent particles by macrophages can be observed as well as neutrophils and red cells in this field. c. Four days after talc instillation, birefringent particles are visible in both macrophages and neutrophils; lymphocytes are also visible in the field. d. Day 7 after talc instillation, multinucleate cells are seen as well as macrophages with single and multiple birefringent particles. e. Day 14 after talc instillation, true multinucleate giant cells are seen with numerous birefringent particles. Also, a fiber is observed in this giant cell with a 3:1 aspect ratio. f. Control group for granite instillation studies, again mostly macrophages were observed. g. One day after 2.5% granite particle instillation, uptake of both black colored particles and birefringent particles by macrophages can be observed but these are not as prominent as seen at this time point with talc as well as neutrophils and red cells in this field. h. Four days after granite instillation, both black and birefringent particles are visible in macrophages; lymphocytes are also visible in the field. i. Day 7 after granite instillation, macrophages and neutrophils with single and multiple birefringent particles are seen. j. Day 14 after granite instillation, no multinucleate giant cells were seen with granite at any time point, only numerous macrophages with single and multiple black and birefringent particles. Also, no fibers were observed in any slides of the granite treatment groups