ELECTRON ^MICROSCOPY 



Applications PATHOLOGY: KIDNEY 



A typical example of the utilization of the The method for renal biopsy was intro- 



unbacked negative replica technicjue for the diiced by Iversen et at. (1951) and further 



examination of a paint surface is illustrated developed by Kark and Muerhcke (1954). 



in Figure 7a. The surface in this case is It affords an excellent opportunity to collect 



basically smooth, illustrating a typical cellu- material for electron microscopy from living 



lar pattern. Loose material attached to the patients with different stages of kidney dis- 



replica during stripping can be observed in ease. As a consequence of this the electron 



the background. The micrograph of the paint microscope is used in many institutes all over 



surface illustrated in Figure 7b was prepared the world where human renal pathology is 



by the backed negative replica technique, studied, and several reports have been pub- 



The roughness in this case appears to be lished concerning this subject.* 



caused primarily by pigment flocculates near A large number of electron microscopic in- 



the air interface. vestigations of experimentally produced re- 



The positive replica technique using a wa- nal lesions in animals have also been per- 



ter-soluble intermediate with either carbon formed. It must be emphasized, however, 



or silica as the final replica offers more ver- that experimental lesions are not always 



satility than the simple negative technique identical to human diseases. Our investiga- 



and for this reason is used quite extensively tion on the normal anatomy of the human 



in the study of paint surfaces. kidney has also convinced us that there are 



Tj'pical examples of the utilization of this important morphological differences between 



technique for the examination of paint sur- the kidney of man and that of animals. Thus 



faces are illustrated in Figures 8a, 8b, 9a and the diameter of the basement membrane of 



9b. Figure 8a shows an enamel with a smooth the glomerular capillaries has been calculated 



o 



glossy surface while Figure 8b shows a flat at 800-1200 AU in different animals and 



o 



pamt with a roughened surface. Figure 9a at about 3500 AU in adult man (Bergstrand 



demonstrates an automative enamel before and Bucht, 1958). The "physiological" varia- 



weathering, while Figure 9b illustrates the tions due to differences in function of the 



enamel after outdoor exposure to test the re- tubular epithelial cells seem to be much 



sistance of the coating to weathering. greater in man than in animals which are 



inbred and kept under uniform environ- 



Acknowlegments.TYie author is indebted to Mr- ^^^^^^^ conditions (Bergstrand and Ericsson, 



A. Jbi. Jacobson for helpful discussions and to the -,^rr^^ m^ i ^- • i i-i 



National Lead Company for supporting this pro- ^^^^^^ ^^us observations on animal kidneys 



gram. should be carefully and critically evaluated 



when used in discussions of human path- 



REFERENCES ology. 



L Bradley, D. E., J. Appl. Phys., 5, 65-6 (1954). The word "pathological" must also be used 



2. Bradley, D. E., J. Appl. Phys., 27, 1399-1412 with great care. The electron microscope re- 



^^^^^^- veals cell organelles such as vacuoles, mem- 



3. Lasko. W. R., Anal. Chem 29 784-786 (1957) . Cranes and mitochondria which are probably 



4. Twiss, S. B., Teague, D. M., and Weeks, ,. ,, , • xi • . . n i 



W. L., Off. Dig 28 93 (1956) continually changing their structure, parallel 



5. BoBALEK, E. G., Lebras, L. R., Powell, A. S., 



AND VON Fischer, W., Ind. Eng. Chem. 46, * When not stated otherwise, all works dealing 



572 (1954). with human pathology and referred to in this 



paper have been performed on material obtained 



W. R. Lasko with this method. 



206 



