OBJECTIVETo search a method for showing dust granules in phagocytes.

METHODSThe autopsy samples of 10 cases who died of non-pulmonary diseases(group A), 6 cases with silicosis(group B) and 5 cases of dead fetus(group C) were collected. The samples of lung, spleen and lymphnodes were stained by methods of (1)HE staining; (2)Warthin-Starry staining(W-S staining) and modified W-S staining; (3) CD68 (as a first antibody) immunohistochemical staining. The ultrastructure and chemical component of the dust granules in the pulmonary phagocytes(dust cells) of group A(3 cases) and group B(3 cases) were observed and analyzed by transmission electron microscope(TEM) and analytic electron microscope(AEM).

RESULTSIn group A and B smaller or minute dust granules which could not be shown by HE staining method were clearly shown by W-S staining and modified W-S staining methods. There were no positive granules found in group C. The CD68 marker of the dust cells was positive. The size, shape, density and chemical elements of the dust granules of group A were different from those of group B under TEM and AEM, excluding bacteria and other intracellular contents.

CONCLUSIONThe dust granules in the phagocytes could be shown by W-S staining method, its staining effect for minute dust granules is superior to general HE staining. However, the determination of chemical elements of dusts must depend on AEM.