ADENYLPYROPHOSPHATASE 



AGONAL^CHANGES 



Adenylpyrophosphatase. The technique of 

 localization of this inaportant enzyme 

 in cytoplasmic granules has been de- 

 scribed and used in extracts of chick 

 embryos by Steinbach, H. B. and Moog, 

 F., J. Cell and Comp. Physiol., 1945, 

 26, 175-183. These authors are, how- 

 ever, not sanguine about the feasibility 

 of its localization by histochemical 

 methods (Science, 1946, 103, 144) as 

 reported by Glick and Fischer, Science, 

 1945, 102, 429^30. However, Malngwyn- 

 Davies, E. D. and J. S. Friedenwald, 

 J. Nat. Cancer Inst., 1950, 10, 1379, 

 recently reported at the Histochemical 

 Society that specific localizations were 

 achieved when unfixed frozen sections 

 were incubated in muscle adenosine 

 triphosphate substrates. 



Adermin, see Vitamin B6. 



Adhesiveness, or stickiness of cellular sur- 

 faces is a phenomenon of great im- 

 portance in connection with movement, 

 phagocytosis embryological develop- 

 ment and other processes. There is no 

 standard technique to measure it, ex- 

 cept in special circumstances as when 

 it ia manifested by agglutination of 

 bacteria and sedimentation of red blood 

 cells. The way leucocytes stick to the 

 endothelial wall of a small blood vessel, 

 shown by Motion Pictures, is impres- 

 sive. Adhesion tests have been intro- 

 duced as means of diagnosis of various 

 trypanosomes. A fine general discus- 

 sion of this phenomenon is provided by 

 Beams and King in Calkins, G. N. and 

 Summers, F. M., Protozoa in Biologi- 

 cal Research. New York: Colombia 

 University Press, 1941, 1148 pp. 



Adrenal. For routine purposes fix in 

 Zenker's Fluid and stain paraffin sec- 

 tions with Hematoxylin and Eosin. 

 There are many techniques for Lipids. 

 The Chromaffin Reaction is often used 

 for adrenalin but Cramer, W., J. Path. 

 & Bact., 1937, 44, 633, considers black- 

 ening with osmic acid vapor as more 

 specific. Silver methods for vitamin 

 C are difficult to apply but are appar- 

 ently reliable. They are given under 

 Vitamins. The Schultz cholesterol test 

 gives excellent results. A selection 

 may be made from several methods for 

 Reticular Fibers. Corner, G. W., Con- 

 trib. to Embryol., Carnegie Inst., 1920, 

 9, 87-93, employed for reticulum the 

 Bielschowsky-Maresch silver method 

 exactly as specified by Ferguson, J. S., 

 Am. J. Anat., 1912, 12, 277-296. The 

 Bodian protargol method for nerve 

 fibers has been adjusted to the adrenal 

 by MacFarland, W. E., and Davenport, 

 H. A., Stain Techn., 1941, 16, 53-58, 

 also Cajal's chloral hydrate method. 

 If one contemplates ultracentrifugation 



and the demonstration of the Golgi 

 apparatus consult Guyer, M. F., and 

 Claus, P. E., Anat. Rec, 1939, 73, 

 17-27. 



Method proposed by Bennett, S. H., 

 Am. J. Anat., 1940, 67, 151-227 for keto- 

 steroid cortical hormone said by Go- 

 mori, G., Proc. Soc. Exp. Biol. & Med., 

 1942, 51, 133-134 not to be specific but 

 to indicate merely location of lipids 

 having keto or aldehyde groups. A 

 technique for microscopic study of 

 living grafts of adrenal cortex (Wil- 

 liams, O., Anat. Rec, 1945, 91, 307). 



Adrenalin, see Chromaffin Reaction. 



Aerosol, a detergent used in preparing bac- 

 teria for staining (Sineszko, S. F., 

 Science, 1942, 96, 589). 



Affixatives are materials used to fix sections 

 to slides. See Albumen-Glycerin. 



Agar, as matrix for cutting plant material 

 with freezing microtome (Evenden, W. 

 and Schuster, C. E., Stain Techn., 

 1938, 13, 145^146). Lillie (p. 42) says that 

 infiltration of tissues from water in 2% 

 aq. agar at 55-60°C. for 2-4 hrs. is useful 

 for holding friable tissues and exudates 

 in place before cutting frozen sections. 

 The Agar does not color appreciably 

 with the usual stains. 



Age Changes are as manifold as life itself. 

 Some are detectable by structural 

 modifications while others can only be 

 measured by decrease in performance. 

 Many old tissues can easily be dis- 

 tinguished from new ones as for example 

 Bone. Some accumulate definite prod- 

 ucts with age like Lipofucsin. The age 

 of tissue and of cellular components, 

 that is the time they endure, can be 

 determined by attaching Tracer Sub- 

 stances to them so that their rates of 

 Replacement can be measured. With 

 the passage of time colloids age, become 

 less elastic and more granular. Old 

 Elastic Fibers can be distinguished from 

 young ones. Now that the ultra struc- 

 ture of Collagenic Fibers has been re- 

 vealed by the electron microscope we 

 may hope for more accurate means of 

 estimating their condition in relation 

 to age. Numerous physical techniques, 

 including the Polarization Optical 

 Method, may well bring to light sig- 

 nificant age changes. Obviously many 

 methods of chemical analysis and of 

 enzyme activity provide data on the 

 modes of run down of vital activities. 

 Aggeler, see Blood Platelets. 

 Agonal Changes are particularly difficult 

 to avoid in villi of small intestine. 

 They are evidenced by a ballooning of 

 the epithelial cap most marked when 

 absorption of ordinary food stuffs is 

 active. The ballooning phenomenon 

 can be produced in the living animal by 



