The pattern of distribution and the shape of the most obviously positive cells leads me to conclude that they are macrophages.
If I am correct, there are two populations of positive large cells, in the alveolar spaces: one is smaller more rounded and intensely positive. The other is slightly larger, irregular, with a seemingly membraneous lighter positivity.There is also a moderate positivity apparently lining the alveoli. I am not yet familiar with this protein.
There are also numerous small cells that are intensely positive.
Sciatic nerve was fixed in 10% Formalin then placed in 1% Osmium for 1hr with gentle agitation. After rinsing well in dist. water the specimen was processed to Pwax. 8 micron section mounted onto subbed slides ( I found that the sections did not adhere well to Superfrost Plus nor PLL – coated slides.Large, intensely black “blobs” are individual adipocytes.