26 ON THE DIFFERENTIAL REACTION TO VITAL DYES EXHIBITED BY 



The fibroblasts are distinguished by the possession of great numbers of deep-blue crystalline 

 deposits, among which are small, angular and filar neutral-red bodies. The typical cell contains at 

 least as many neutral-red as blue deposits. Their morphology is almost exclusively seed-shaped 

 and linear, though some instances of small, almost round, though angular, deposits are seen. Large 

 crystalline masses are not uncommon, as shown in the drawing (fig. 49). 



In conclusion, it is to be emphasized that almost all of the deposits in the most frequently 

 occurring cell are crystalline in nature, whether they be deep blue or only orange from neutral red, 

 and they are almost invariably quite delicate structures. 



Same animal was injected with a 0.1 per cent solution of dye T 148, March 30 to April 14, 

 inclusive, 1 c. c. each day. 



April IS: Subcutaneous tissue was examined from left thigh. The low-power view shows deep- 

 blue deposits in all cells. 



The fibroblasts do not appear to have changed significantly from the last autopsy date as far 

 as their blue crystalline deposits are concerned. They still contain remarkably sturdy, deep-blue, 

 purely crystalline structures, with now and then the occurrence of a single deep-blue vacuole, which, 

 however, often shows some angular distortion. These cells are, in addition, full of pale-yellow T 148 

 bodies, spherical or angular and of fairly uniform size (fig. 52). 



The macrophages are on the whole remarkably small cells filled with vacuoles, the great majority 

 of which are pink. Small fat vacuoles are numerous. These cells lie in colonies, as if cell division 

 had taken place. Tney contain deep-blue deposits, usually in the form of short, straight crystals 

 included within vacuoles which are either pale pink or pale blue. The amount of deep blue in the 

 macrophages is extremely variable as one goes from one cell to another. A few contain red vacuoles 

 only. Many contain but one vacuole filled with deep-blue crystals and often much larger than the 

 typical T 148 vacuoles (the majority of which are about the size of mast-cell granules) (fig. 51). 

 Macrophages containing a great quantity of deep blue are rather rare. Pale-blue crystals are so 

 infrequent in these cells as to be negligible, although in the cells containing a great quantity of blue 

 dye many deposits show no pink and preserve a crystalline nature, though usually connected with 

 deep-blue vacuoles. 



On the whole, the picture is identical with that found before, as far as the blue deposits are 

 concerned, in the fibroblasts. The T 148 has formed vacuolar deposits which take the place of and 

 are more numerous than the round and linear neutral-red bodies described before, but the deep-blue 

 (crystalline) deposits seen before are not supplanted or even inclosed by the T 148 vacuoles. 



Same animal injected with a 0.5 per cent solution of dye T 148, April 15 to 29, inclusive, 

 May 1, 3, 5, 7, 9, 11, 1 c. c. each day. 



May 13: Examined subcutaneous tissue from abdomen. Animal stained a deep purplish blue. 

 Subcutaneous tissue looks bright blue to the naked eye. 



Under the oil, cell differentiation is easy. The macrophages are undoubtedly chiefly responsible 

 for the purple color, their abundant intermediate-sized vacuoles being usually pale heliotrope in 

 color, the larger ones tending toward blue. No instances of crystals can now be seen, but deep-blue 

 masses exist in these larger vacuoles as well as in some of the smaller ones. 



The fibroblasts now give the impression of being stained with dye T 148 rather than with trypan 

 blue. Their cytoplasm is gorged with dye T 148 vacuoles which have a pale pinkish-yellow color. 

 A great many fibroblasts, however (almost half of them) contain 1 or 2 deep pure blue, seed-shaped 

 trypan deposits, and in some cells the number of these bodies may reach 15 or 20. Some films show 

 practically all of the fibroblasts as elliptical, rounded-up elements, with their protoplasm full of great 

 numbers of entangled pale yellowish-pink " threads." These cells are not different in their trypan 

 blue deposits from others, i. e., perhaps half of them are free from trypan-blue deposits. A great 

 number have 2 or 3 such deposits, and others a considerable content (15 to 25). 



The persisting deep-blue color of the animal shows that much trypan blue is still present, and 

 the microscopic picture shows that most of the dye is present in the macrophage cells, where its 

 contamination, however, with the subsequent red-dye treatment allows no pure-blue deposits to be 

 6een. The majority of the fibroblastic blue deposits have disappeared, but those persisting are still 

 pure deep blue and are the only uncontaminated deposits now present in the skin. It is likely that 

 continued T 148 dosage will give great numbers of entangled threads in fibroblasts all over the 

 body; they are here very abundant over the whole abdomen. 



Injection of a 0.5 per cent solution of dye T 148 continued, May 14, 17, 20, 23, 27, 31, June 

 2, 4, 6, 8, 10, 12, 14, 16, 19, 21, 23, 25, 27, and 29, 1 c. c. each day. 

 July 17: Autopsied. Animal is stained a reddish violet or heliotrope. Abdominal skin is 

 reddish heliotrope. The low-power view shows that vital-dye deposits are so lacking in color as to 

 be barely capable of detection, all cells being faint pink. 



