X-ray microanalysis of Michaelis--Gutmann bodies in human malakoplakia (kidney and testes) and in that of rats induced experimentally by administration of endotoxin of Escherichia coli, was carried out. The presence of calcium could be revealed in every Michaelis--Gutmann body according to the lines of Kalfa and K3 as well. The amount of it was in correlation with the stage of the calcification. In the Michaelis--Gutmann bodies found in the rat kidney, fixed without OsO4 presence of P could also be demonstrated. The correlation between the weight per cent of Ca and P seems to evidence the presence of CaHPO4. Results of the X-ray microanalysis of Michaelis--Gutmann bodies found in human and in experimentally induced malakoplakia appeared to be similar.
The structure and acid phosphatase activity of vacuoles observed in regenerating proximal renal tubules were examined ultrastructurally. The sequestration and degradation of organelles were followed in the vacuoles, which obtain the acid phosphatase presumably from the lysosomes, and the limiting membrane of which originates from the endoplasmic reticulum. The vacuoles are regarded as autophagic vacuoles. Their appearance is correlated with the commencing differentiation of the dedifferentiated regenerating cells, which have similar regenerative phenomena.
Malakoplakia in kidney of rats was caused experimentally by injection of large quantities of not purified endotoxin-antigen complex of Escherichia coli 0 75 (O. coli 127 97 CDC 0 group 75; American Type Culture Collection, Eight Edition 1968, page 24). The extract in the beginning became surrounded by leukocytes, later by macrophages. The latter then were transformed into characteristic Hansemann cells. From the 8th day on started the depletion of calcium phosphate in the cytosegresomes of macrophages, thus forming the Michaelis-Guttmann bodies, necessary for the diagnosis of malakoplakia. It is believed that complex of endoxin- and antigen of Escherichia coli may take a part - at least in certain cases - in formation of malakoplakia in human.
In the myocard and kidney of rats perfused with Karnovsyk's solution for 5--10 minutes then fixed for two more hours and postfixed in 1 per cent solution of osmium tetroxid in Millonig buffer, characteristic electrondense granules were observed. The structure of the organ appeared to be normal. Although the granules appeared to be diffuse, they presence was most marked on the membranes, on the surface of erythrocytes and in the pinocytic vacuoles both on counterstained slides and on those of without counterstaining. When postfixation was carried out with osmium-tetroxide solved in Veronal buffer artefacts did not occur. To avoid artefacts fixation in glutaraldehyd should not be followed by a postfixative containing phosphate buffer.
Behaviour of the epithelium of seminiferous tubules and interstitial tissue was studied in malacoplakia induced by administration of an extract of E. coli. Necrosis of the epithelium of seminiferous tubules developed immediately and it was replaced by granulocytes, and histiocytes, phagocytizing both, bacterial extract administered and disintegrated cells. Tunica propria was thickened by inflammatory cells. Hansemann cells were observed not only in the interstitium but between the layers of the tunica propria and on the place of the necrotized epithelium of the seminiferous tubules. Although Sertoli cells possess phagocytizing activity it could not be proved, that Hansemann cells are taking their origin from them.