Page:Acute Poliomyelitis.djvu/35

PATHOLOGICAL ANATOMY 23 According to Wickman, each acts quite differently. The poly- blasts alone are active neurophages. In the middle of many gan- glion cells, degenerating polynuclears lie ; but around the periphery the polyblasts are situated and generally show no retrogressive changes. The difference in behavior of the polynuclear leucocytes and of the polyblasts is especially noticeable in places where the ganglion cells have already been ingested. In Fig. 1, the two poly- nuclear leucocytes, which are somewhat to the left above and to the right below the center of the field, remain quite passive; whereas, the protoplasm of the polyblasts is swollen and laden with tiny particles of fat. In addition, other ingested material, appar-

ently decaying ganglion cells, is present. These fat-laden poly- blasts develop later into typical fat cells.

The neurophages also occur in poliomyelitis in monkeys (Land- steiner and Levaditi, Landsteiner and Prasek) and are, I think, a feature especially peculiar to the most acute cases. In cases of slower course, the changes earlier described are evident. In perhaps not a few, a degeneration which I described in my first work on this subject, occurs; the peripheral part of the cell body degenerates and dissolves, but the nucleus is spared. If such cells are situated in areas of infiltration, the appearance may resemble a complete absorption of the ganglion cells, unless a careful exami- nation with a high power lens be made, when the presence of the