and Laboratory Methods. 1823 



NORMAL AND PATHOLOGICAL HISTOLOGY. 



JOSEPH H. PRATT, Harvard University Medical School. 



Books for Review and Separates of Papers on these Subjects should be Sent to Joseph H. Pratt, 

 Harvard University Medical School, Boston, Mass. 



Locke and Cabot. lodophilia. J. of Med. Re- Locke and Cabot in a preliminary re- 

 ' * 5 4,9- pQj.^ from the Massachusetts General 



Hospital (The Journal of Medical Research, January, 1902) discuss the subject 

 of iodophilia. This is the reaction which certain of the white cells of the blood 

 show when a dried blood-film is brought in contact with the following solution : 



Iodine, ...-.- 1 gram. 

 Potassium Iodide, ... 3 grams. 



Water, - - - - - 100 c. c. 



Gum arable, 50 grams. 



This mixture was first suggested by Ehrlich, though the reaction had been 

 long known. The technique consists in a cover-glass film being prepared in 

 any of the usual ways and allowed to dry in the air. Without any fixation it is 

 then pressed down upon a drop of the iodine solution on a slide and examined 

 with an oil immersion lens. If the blood be normal the red cells are uniformly 

 colored a bright yellow upon a much fainter background, while the white cor- 

 puscles are stained of about the same tint, their nuclei being somewhat more 

 refractile. 



In certain pathological conditions the iodine reaction is noted. This consists 

 in the uniform yellow coloration being broken by the appearance in the proto- 

 plasm of the polymorphonuclear neutrophiles of reddish brown granules, or a 

 diffuse brownish coloration, and by the presence of small and large masses out- 

 side the corpuscles similarly colored. The reaction then may be extra-cellular 

 or intra-cellular. In rare cases basophiles and myelocytes react. In their ex- 

 aminations, as a routine, at least one hundred cells were counted ; if in that 

 number none were observed with either a diffuse or granular stain they consid- 

 ered the reaction negative. The history of the reaction is briefly given. The 

 observations of the different observers have been quite varied. Locke and Ca- 

 bot studied the reaction in 432 cases. They give a table of their results from 

 such a study and follow it with brief histories of eight cases to show the practi- 

 cal application of this reaction in differential diagnosis. 



They conclude that the increase of extra-cellular bodies is of little signi- 

 ficance. Intra-cellular granules, however, are never found in normal blood and 

 they believe them to be pathological. In regard to iodophilias, they assert : 



(1) It signifies not a special disease or condition, but a general toxemia. 

 The diagnosis of pus, however, should not be made from this condition alone. 



(2) It is not identical with, neither does it coincide in its indications with 

 any of the ordinary physical signs, as leucocytosis, fever, etc. 



(3) It appears to be certain evidence that the patient is sick. It is a more 

 reliable sign than either leucocytosis or fever. 



