78 The Lymphocyte and Lymphocytic Tissue 



BLISTER: SUPRAVITAL METHOD 



Technique 



The blister technique permitted continuous direct observation of the lym- 

 phocyte macrophage transformation in supravital preparations. The blisters 

 were produced on the volar surface of the forearm following the 

 application of Chinese cantharides and a petrolatum mixture on a 1.5 cm. 

 circular area of the skin. The area was covered with adhesive tape to 

 exclude air. In approximately 7 hours a 0.5 cm. blister is formed. A mixture 

 of egg albumen and neutral red solution in a physiologic saline solution 

 was injected into the blister. Interval aspirations of a small amount of the 

 blister fluid (via a #25 syringe needle) were studied as supravital prepara- 

 tions in a warm-stage enclosure. 



Results 



A lymphocyte from the exudate aspirate 7 hours and 55 minutes after 

 the application of cantharides resembled the lymphocyte as seen in the 

 peripheral blood and was characterized by its small size, round nucleus, 

 scant cytoplasm, and the absence of neutral red vacuoles. This cell was 

 maintained under direct, continuous observation, and 15 minutes later 

 (8 hours and 10 minutes) the nuclear membrane reflected marked activity 

 (represented by a seriated border) in the area of acquired neutral red 

 vacuoles. At an interval of 8 hours and 25 minutes (30 minutes after the 

 initial observation of this cell), this lymphocyte developed a deep cleft 

 or indentation of its nucleus, an increase in cytoplasmic mass, and 9 

 neutral red vacuoles. 



Another lymphocyte from the aspirate of 1 1 hours and 20 minutes was 

 observed. Nineteen minutes later (11 hours and 39 minutes) it had in- 

 gested three albumen particles and had neutral red vacuoles. 



At 1 1 hours and 46 minutes, it was in contact with the neutrophilic 

 bud but apparently did not ingest it. There was some slight increase in 

 cytoplasmic mass. 



At 11 hours and 51 minutes, the cell showed an indentation of the 

 nucleus, ingested egg albumen, and from 7 to 15 neutral red vacuoles. 



At 12 hours and 5 minutes (45 minutes after it was first observed), the 

 nuclear mass had increased, and the nuclear membrane reflected marked 

 activity. The amounts of cytoplasm and neutral red vacuoles were also in- 

 creased. In the subsequent minute it developed a horseshoelike nucleus 

 and a further increase in neutral red vacuoles. The vacuoles had a rosettelike 

 arrangement near the cytocentrum. 



