CANCER 



50 



CAPILLARIES 



Cancer. Because cancer and other malig- 

 nant tumors can develop in so many 

 organs and tissues that contain inter- 

 niitotic or reverting postmitotic cells 

 (Cell Classification), techniques de- 

 signed to compare the malignant cells 

 with their non-malignant prototypes 

 are altogether too numerous to mention. 

 They will be found under the several 

 tissues: Pancreas, Connective Tissue 

 and so forth. 



There is no known technique which 

 will reveal a structure or a substance in 

 cancer cells wholly absent in normal 

 cells of the sort from which the particu- 

 lar cancer cells have originated. 

 Neither can the reverse be demon- 

 strated, that is something absent in 

 cancer cells and present in normal ones. 

 Available methods are only capable of 

 demonstrating quantitative differences 

 in properties exhibited by normal and 

 malignant cells. Properties of cancer 

 cells have been systematically reviewed 

 by Cowdry, E. V., Arch. Path., 1940, 

 30, 1245-1274. Yet the Dopa Reaction 

 is of service in diagnosis of Melano- 

 carcinoma. 



Frequently it is helpful to excise can- 

 cers and transplant them into other 

 situations such as the Anterior Chamber 

 of the Eye where they can conveniently 

 be studied. The Tissue Culture 

 method is of great service, likewise 

 Motion Pictures made of cancer cells. 

 The most recently developed line of 

 investigation is bj^ Radioactive Isotopes. 



Candida Albicans. Method for demonstrat- 

 ing this parasite with fat soluble dyes 

 in frozen sections by Fuentes, C, J. 

 Bact., 1946, 51, 245-246. 



Cannulas. Glass cannulas are required for 

 insertion into blood vessels in the Per- 

 fusion technique. To make one of about 

 the size for guinea pig's thoracic aorta 

 file and break 6 mm. outside, 4 mm. 

 inside diameter soft glass tubes into 

 pieces about 15 cm. long. (Pyrex of 

 this size will do. It requires a little 

 more heating.) Take one of these, 

 place middle in gas flame rotating it so 

 as to heat it evenly. When fairlj- soft 

 remove from the flame, draw the ends 

 apart to a distance of about 50 cm. and 

 hold until solid. File and break in the 

 middle. With a little practice this will 

 give two tubes, each tapering evenly 

 from the 6 mm. outside diameter to 

 about 2-3 mm. within a distance of 

 approximately 3 cm. Next bring the 

 tube where it has a diameter of 2-3 mm. 

 near to a fine flame, like that of a small 

 alcohol lamp. Let it get soft and pull 

 just enough to produce a slight narrow- 

 ing to be used later to prevent the 

 thread employed to tie the cannula in 

 the vessel from slipping. Then fracture 



with file and break off the thin end 

 about 4 mm. beyond the constriction 

 and distant from the wide part of the 

 tube. If this break can be made at an 

 acute angle to the length of the tube, so 

 much the better; because then one rim 

 of the small end of the tube will project 

 out beyond the rest which will facilitate 

 its insertion into the vessel to be cannu- 

 lated. When the break is made across 

 the tube, at right angles, the rim on one 

 side can be ground down on a water stone 

 so as to produce a similarly projecting 

 lip. In either case it is necessary to 

 remove sharp cutting edges from both 

 ends of the cannula by smoothing in a 

 flame. The 6 mm. wide body of the 

 cannula should be 3-4 cm. long for con- 

 venient attachment of rubber tube. 

 Obviously larger cannulas are required 

 for larger vessels. Those for Micro- 

 injection are very much smaller, made 

 of hard glass and do not require to be 

 tied in. 

 Capillaries. In living humans these can 

 best be seen in the skin by the method 

 of Capillaroscopy. Render the epider- 

 mis at the root of the finger nail trans- 

 lucent by addition of a drop of highly 

 refractive oil and examine directly at 

 fairly high magnification the capillary 

 loops in the dermal papillae. It is 

 possible to record their changes by 

 making moving pictures through a long 

 period of time. See review by Wright, 

 I. S. and Druryee, A. W., Arch. Int. 

 Med., 1933, 52, 54.5-575. See also 

 Gingiva. 



In living mammals the most favorable 

 site in which to watch capillaries at high 

 magnification is in the transparent 

 chambers of the Sandison's Technique. 

 For shorter periods they can be studied 

 in the displaced but living pancreas by 

 the methods of Covell, W. P., Anat. 

 Rec, 1928, 40, 213-223 and O'Leary, J. 

 L., ibid, 1930, 45, 27-58. Some changes 

 in Permeability of living capillaries are 

 evidenced by the trypan blue capillary 

 permeabilitj'- test. If microdissection 

 is intended and a shift to the tongues 

 and nictitating membranes of frogs is 

 made consult Zweifach, B. W., Anat. 

 Rec, 1934, 59, 83-108, and Am. J. Anat., 

 1937, 60, 473-514. The results have 

 been recorded in moving pictures. 

 Supravital staining of the tissues just 

 mentioned with janus green (Bensley, 

 R. R., and Vimtrup, B., Anat. Rec, 

 1928, 39, 37-55) affords beautifully clear 

 views of the muscular elements of 

 arterioles grading into capillaries. See 

 Perivascular Cells, Rouget Cells. 



For investigations on the topographic 

 arrangement of capillaries arterial injec- 

 tions with Carmine, Berlin Blue or 

 some other easily recognizable material 



