and Laboratory Methods. 2393 



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. 



Buxton, B. H. Enzymes in Tumors. Journal It has been shown within recent years 

 ofMedicalResearch,9: 356-371,1903- j^at in addition to the extracellular 



enzymes which are secreted into the digestive tract, there are intracellular en- 

 zymes in the animal body, in organs not concerned in the formation of 

 the digestive juices. Buxton did not use filtered extracts owing to the diffi- 

 culty of obtaining sufficient amounts of cancerous tissue. Instead, he tested for 

 the presence of enzymes by means of diffusion in agar plates. This method is 

 simple, and he thinks it will prove trustworthy. 



Each tumor was chopped into fine bits and ground up with pumice stone in 

 a mortar. A soft paste was made by the addition of fifty per cent, glycerin in 

 water. The pulp divided into equal parts was placed in two sterile bottles 

 labelled A and B. The bottle B was boiled for 20 minutes and more glycerin 

 added to restore the mixture to its original consistence. To each bottle a little 

 chloroform was added. At the end of two or three weeks the pulp became sterile. 



A two per cent, agar was prepared. When needed it was melted and a little 

 thymol added. After it had cooled down to 50°C. or 60°C. the substance 

 required for the reaction was added. About 15 c. c. of agar were poured into 

 each Petri dish. A small spoonful of the pulp from each of the bottles was 

 placed on the agar and arranged in the form of a circle 20 mm. in diameter. 

 One semi-circle was composed of pulp from A, the other half of pulp from B. 

 The Petri dish was kept in an air tight incubator at 40°C. and exposed to vapor 

 of chloroform water. 



Proteolytic enzymes, (a) Egg albumen. Suspension of 5 per cent, of white of 

 egg in agar. If a proteolytic action occurs the slightly opalescent agar becomes 

 clear. None of the tumors acted upon the egg albumen. (l>) Milk. Agar, 90 

 per cent.; sterilized milk, 10 per cent. Varying results were obtained with 

 different tumors. Some produced coagulation (rennet) with subsequent clearing. 

 (e) Gelatine. Ten per cent, gelatine with a little thymol. Some tumors caused 

 liquefaction of the gelatine. 



Amylase. Two kinds of agar plates were used. One contained 0.5 per 

 cent, of soluble starch, the other 0.25 per cent, of glycogen. At the end of 48 

 hours a 3.5 per cent, solution of HCl is poured over the plates and then drained 

 off, and diluted Lugol solution poured on. Except where sugar has formed the 

 starch is colored blue and the glycogen brown. All the tumors caused some 

 fermentation. 



Lipase. One per cent, butyrin in litmus agar. The medium should be just 

 alkaline enough to color the litmus blue. If lipase is present in the substance 

 tested fatty acids will be formed and the litmus changed thereby to red. This 

 reaction occurred with all the tumors, but normal organs probably have the same 

 action. 



Oxidases. An emulsion is made by adding to a little distilled water in a por- 

 celain dish some saturated alcoholic solution of gum guaiac. The dish is tilted 

 and some tumor pulp placed at the margin of the fluid. If oxidation occurs a 

 blue color appears. With none of the tumors did this reaction take place. 



Peroxidases. On adding a little H2O2 to the guaiac fluid a blue color is 

 formed if peroxidases are present. All the tumors responded to this test, but so 

 do normal tissues. J. h. p. 



