MEDICO-BIOLOGIC RESEARCH 



animals. These data also remain imelab- it is also necessary to prevent the outflow of 



orated. OM from the capillaries, which frequently 



Montichelli ef al. reported preliminarily happens during cutting. Mindful of this 



that in some cases of hyperthyroidism in- possibility it is better to use as dispersing 



creased absorption of iodine was found in the media solutions of starch, dextrose or gum 



thyroid gland via microradiography. Unfor- arable, because these media are mostly con- 



tunately, neither a further report by these verted into gels after formalin fixation of the 



authors about their results nor information specimen. It is also possible to prevent the 



about the techniciue used is found so far in outflow of OM by keeping the temperature 



the literature. of the section below freezing point for the 



OM is injected subcutaneously in the whole time of exposure. For this purpose the 



method called microlymphography. From interior of the microradiographical cassette 



this depot OM spreads into minute lym- has to be connected with the freezing gas. 



phatic vessels. After several hours the animal Although to our knowledge some researchers 



is sacrificed and the organ of which the use such eciuipment it is not described in the 



lymphatic capillaries should be studied is literature relevant to microvasography. 



taken out and prepared for microradiography Sometimes the outflow of OM may be indi- 



in the normal way. Thorotrast is con- rectly prevented by making use of thicker 



sidered the best OM for this method (14) (39). sections (up to 500 /x). Though microvaso- 



Some authors recommend stereo-micro- graphs of these sections permit only low 



angiography and stereo-microlymphography, magnification they present a good picture 



Since literature data do not mention any sufficient for general orientation in the 



achievement in medical research accom- morphology of capillaries. Some instructions 



plished by these methods their detailed de- on the subject of technique may be found in 



scription is omitted. Any one interested may works of Bellman (12) ; Barclay (7) ; Okawa 



find this not only in the works mentioned and Trombka (93) and others, 

 above but also in publications by Engstrom Post Mortem Selective Coloring by 



(55) ; Oden et al. (92) ; Pattee et al. (95). OM. The first indication in the literature on 



Direct Injection of OM Post Mortem, the possibility of post mortem coloring may 



There is a wide choice of OM with particles be found in the work of Clark (38) and 



small enough to pass through the narrowest Mitchell (89). It was pointed out that some 



capillaries. Many iodine compounds (dio- qM are absorbed selectively by different 



drast, pantopaque, uroconsodium, tele- biological tissues. As was mentioned above 



paque, etc.); colloidal solutions (thorotrast, ^.^ ^^^^^^ ^^ ^^^ ^j^^ ^^^^ "adsorption" 



umbrathor, colloidal bismuth, etc.); emul- .^^^^^^^ ^^ "absorption" for the initial stages 



sions (micropaque, bismuth subcarbonate ^^ ^^ consumption because OM is at first 



etc.) ; various preparations of mercury and ^^^^^^.^^^ ^^^^^.^^ ^^^ ^^^^ membrane and only 



other OM are used for this purpose. ,^ . -^ u ^ j vu- +u 



^, , . ., ,. I- r^^T • \ J. • after some time may it be found withm the 

 The administration of OM into arteries or 



veins is carried out along general lines, ce as we • 



covered in textbooks on anatomical and ^^ ^^^ "^^^hod of coloring a ^ect.on of 



pathological techniques. One should be care- biological tissue is immersed into OM solu- 



ful to avoid any forcing during the filling of tion for several hours, then washed, dried 



the vessels with OM. Extravasation caused and radiographed. It was found that some 



by torn capillaries or aterioles can produce a embedding media (e.g., paraffin, ceUoidin) 



non-existing contrast in a large area of the impede the normal adsorption of OM. There- 



microradiograph. As was mentioned above, fore, they have to be removed before immer- 



605 



