l() LOCAL ILSSl'E REACTIVITY 



jcttioii ol siil).staiuc.s hjweiiiig the capillary pernical)ility (uie- 

 tliaiic. j)laiii hroiii, and Besredka antivirus) into the skin sites 

 prepared with bacterial fdtrates enhanced the severity of lesions 

 provoked by the intraxenous injection of the bacterial filtrate. 



In my studies on the titration of skin-j^reparatory factors sidj- 

 sec[uently described, it was essential to determine xvhether va- 

 rious sites of the skin of the abdominal xvall responded similarly 

 to diluted fdtrates. Incidental observations xvhich xvere never car- 

 ried out systematically, suggested that high dilutions (i:()4) of the 

 filtrates elicited xveaker reactions in the upper and lo\\'er left 

 cpiadrants o^ the skin of the al)dominal xvall than in the upjier 

 and Ic3wer right (juadrants. Recent investigations of Koplik 

 (19^57) demonstrate that the prej)aratory factors are rapidly spread 

 by means of the lymphatics inasmuch as lym])h nodes adjacent 

 to the prepared skin sites shoxv distinct hemorrhagic reactions 

 as \ve\\ illustrated by his figmes. It is possible, therefore, that the 

 spreading of a reaction may depend on the richness of the lym- 

 phatic network in a given area. 



The skin of \arious parts of the body of the rabbit seem to 

 differ to a certain extent in susceptibilit) to the phenomenon. 



In my recent unpublished experiments, rabbits received four 



1. Section of hypogastric lymph node, six hours after intravenous injection of 

 filtrate from cuUme of B. txplwsits given following preparatory injection of same 

 filtrate into afferent lvm|3hatic. Dilated veins are partially thrombosed. Macrophages 

 containing red blood cells are in lymph sinuses. Hematoxylin and eosin. X 160. 



2. Arteriole in hypogastric node, showing swelling and hyaline degeneration ol 

 wall and necrosis of endothelial cells. There is perivascidar edema but no cellular 

 infiltration. Animal killed six hours after intravenous injection of filtrate of menin- 

 gococcus cultine administered twentv-four hours subsequent to injection of this 

 filtrate into circumflex abdominal lymphatic. Hematoxylin and eosin. X 600. 



9. Sections of right (R) and left (L) pectoral nodes. Animal was given in- 

 travenous injection of filtrate from a culture of B. typhosus t\venty-foin- horns after 

 l^reparatory injection of same filtrate into skin of right side of abdomen. Right 

 pectoral node is swollen, congested and contains a large area of hemorrhage. Left 

 pectoral node is normal in appearance. 



7. Section of vein in left common iliac node, which received intravenous injection 

 of filtrate from a culture of B. typhosus twenty-four hours after preparatory in- 

 jection of filtrate into skin of medial surface of left thigh. Vein contains a thrombus 

 adherent to endothelial cells which are swollen and take nuclear stain lightlv. Note 

 there is no perivascular cellular infiltration. Reaction was negative at injected skin 

 site. Hematoxylin and eosin. X 650. 



5. Regional inguinal lymph node removed twenty-four hours after an intra- 

 dermal injection of filtrate of cidture of B. typlwsus into right lower quadrant of 

 abdomen. Section shows edema of node. Blood vessels are empty and not dilated 

 or thrombosed. Compare with /. Hematoxylin and eosin. X 160. (Koplik, 1937.) 



