1. Tongue: Herpes Simplex Glossitis Lab 8, Case 1

2. Cross section of the tongue There is an area along the surface of the tongue where the normal epithelium has been lost and there are areas of ulceration (arrows).

3. 1: Epithelium 2: Edge of the ulcer 3: Ulcerated epithelium There is an inflammatory exudate at the base of the ulcer and some necrotic cells where the epithelium once was present.

4. Edge of the ulcer Even at this power, amphophilic (dark, blue-purple-staining) intranuclear inclusion bodies can be seen in the epithelial cells. Note the inflammatory infiltrate in the subepithelium.

5. Epithelium at the edge of the ulcer Amphophilic intranuclear inclusion bodies can be seen in almost all of the epithelial cells in this section.

6. Epithelium at the edge of the ulcer The cells that have been invaded by the herpes virus contain intracellular accumulations of amphophilic viral inclusions (arrows).

7. Brain: Herpes Encephalitis Lab 8, Case 2

8. Multiple small, punctate hemorrhages throughout the brain parenchyma (arrows)

9. Section of brain with numerous perivascular hemorrhages (arrows) and some areas that appear hypercellular

10. Blood vessel with perivascular hemorrhage (1), areas with loss of brain parenchyma, and edema (2) Even at this power, it can be seen that many of the cells are shrunken and dark red, suggesting that they are necrotic.

11. Higher power of previous section At this power it is easier to see the blood vessel with the perivascular hemorrhage and lymphocytic cuffing (1). In addition, the areas of edema and loss of neutrophil (2) can be better appreciated. Red shrunken neurons and glia with pyknotic nuclei (3) are also evident.

12. Blood vessel with perivascular hemorrhage and mild perivascular lumphocytic cuffing (arrow) In addition, there are numerous red shrunken neurons and glia with pyknotic nuclei throughout this section.

13. Clear areas indicate edema 1: Numerous shrunken red necrotic cells At this power, it can be seen that eosinophilic intranuclear inclusion bodies have displaced chromatin to the periphery of the nucleus in some cells (2).

14. Arrows: Necrotic Cells

15. Cells containing intranuclear inclusion bodies (arrows)

16. Cell containing an intranuclear inclusion body (arrows) Note that the chromatin has been pushed to the outer edges of the nucleus.

17. Cell containing an intranuclear inclusion body (arrows)

18. Brain section stained with antibody against herpes simplex Even at this magnification, it is easy to pick out cells that are positive for the virus (arrows).

19. Brain: Rabies Lab 8, Case 3

20. Hippocampus from this case, low power

21. Brain tissue exhibiting edema and evidence of shrunken, necrotic neurons (arrows)

22. Shrunken neurons, higher power One neuron appears to have an eosinophilic intracytoplasmic inclusion body (arrow).

23. Neurons containing variably-sized intracytoplasmic eosinophilic inclusion bodies (arrows)

24. Neuron surrounded by inflammatory cells (lymphocytes and microglia) This neuron has two intracytoplasmic eosinophilic inclusion bodies (arrows).

25. Spinal Cord: Poliomyelitis Lab 8, Case 4

26. Spinal cord from this case Note that the anterior horns (arrows) are almost completely devoid of neurons.

27. Spinal cord Note the absence of motor neurons in the anterior horns and the gliosis (arrows).

28. Anterior Horn of Spinal Cord Note the absence of motor neurons in the anterior horns and the diffuse gliosis.

29. Junction of white and grey matter Note the inflammatory cellular infiltrate and tissue breakdown. There is significant loss of neurons and myelin in this area.

30. Anterior horn with inflammatory cell infiltrate and total loss of neurons

31. Liver: Hepatitis B Lab 8, Case 5

32. Liver from this case This section was stained with a modified aldehyde fuchsin stain and counterstained with H & E. Modified aldehyde fuchsin colors cystine-rich proteins, such as HBsAg and elastic fibers, deep purple. The cytoplasm of most liver cells (and RBCs) stain red due to eosin and have dark blue nuclei.

33. Note the severe congestion (RBCs in sinusoids) and the presence of occasional hepatocytes with dark red/magenta-stained cytoplasm (arrows).

34. Periportal region exhibiting some inflammation and bile duct hyperplasia There is also congestion and some loss of hepatocytes with disruption of the hepatic cords.

35. Numerous hepatocytes containing acumulations of magenta-staining material in the cytoplasm (arrows).

36. Hepatocytes, the cytoplasm of which contain intracytoplasmic accumulations (arrows) of hepatitis B surface antigen

37. Liver section from another case of Hepatitis B In this H & E stained section, the typical “ground glass” appearance of the hepatocytes can be appreciated (arrows).

38. Liver from previous image Reacted with antibody to HBsAg The hepatocytes that contain HBsAg stain brown.

39. Higher power of previous section that shows more clearly the HBsAg positive cells Upon staining with H & E, these same cells exhibit a “ground glass” appearance, which is due to the accumulation of HBsAg in the hepatocyte cytoplasm.

40. Low power of the same liver reacted with antigen for Hepatitis B core antigen (HBcAg) The hepatocytes that contain HBcAg stain brown. Note that even at this magnification, many brown-staining nuclei can be seen.

41. High power of previous section showing HBcAg positive nuclei (arrows)