LYOGLYCOGEN 



187 



MACERATION 



renal lymphatics (Pierce, C. E. 2nd., 

 Anat. Rec, 1944, 90, 315-329). 



Lyoglycogen, see Glycogen. 



Lyons Blue, see Spirit Blue. 



Lymphocytes. There is no specific stain 

 for lymphocytes, but identification is 

 usually easy at least for small lympho- 

 cytes. To observe motility, mount 

 fresh blood and ring with vaseline to 

 prevent evaporation. Movements 



usually begin after the neutrophiles 

 have become active. Examination in 

 the darkfield may be helpful. Mito- 

 chondria can be demonstrated easier 

 in lymphocytes by supravital staining 

 with Janus Green than in polymorpho- 

 nuclear leucocytes because they are not 

 obscured by the specific granulations. 

 In the study of smears the characteristic 

 cytoplasmic basophilia of lymphocytes 

 can be brought out by most of the usual 

 stains (Giemsa's, Wright's). The 

 Peroxidase Reaction of Ijonphocytes is 

 negative, or very strictly limited. 

 Methods demonstrating Cathepsin, Nu- 

 clease, Amylase, Lipase, Lysozyme and 

 Adenosinase in lymphocytes are de- 

 scribed by Barnes, J. M., Brit. J. Exp. 

 Path., 1940, 21, 264-275. To determine 

 the age of lymphocytes is extraordinarily 

 difficult. Perhaps the nearest approach 

 to this goal is the work of Wiseman, 

 B. K., J. Exper. Med., 1931, 54, 270-294. 



Lysis. In histology this term means the 

 solution of a cell resulting from injury 

 to the cell membrane. A choice may 

 be made of several agents productive 

 of this change. As classified by Danielli 

 (Bourne, pp. 74-75) antibodies and 

 px)lyhydroxylic phenols probably act 

 almost wholly on the protein component 

 of the membrane; lipoid solvents, 

 lecithinase, digitonin, sodium or potas- 

 sium salts of fatty acids and paraffin 

 sulphonates mainly on the lipoid part ; 

 and the heavy metals probably on both. 

 He suggests the probable modes of 

 action. It is therefore possible that 

 these lytic agents may in their action 

 provide clues as to the nature of the 

 plasma membrane. See Cell Mem- 

 branes. 



Lysozyme a heat and acid resistant enzyme 

 produced from egg white and isolated 

 as a basic protein of small molecular 

 weight by Abraham, E. P., Biochem. 

 J., 1939, 33, 622-630. It is present in 

 many animal and plant tissues. A 

 method for its determination in lympho- 

 cytes and polymorphonuclear leuco- 

 cytes (neutrophiles) is given by Barnes, 

 J. M., Brit. J. Exp. Path., 1940, 21, 264- 

 275). The use of lysozyme as a cy to- 

 logical agent in bacteriology is de- 

 scribed by Dubos, R. J., The Bacterial 

 Cell. Harvard Univ. Press, 1945, 460 pp. 



Observation that a bacterium is sus- 

 ceptible to lysozyme is an indication 

 that it contains as an essential part of 

 its structure a substrate for this en- 

 zyme, probably an acetyl amino pol- 

 j'saccharide. 

 Lyssa Bodies are small Negri bodies which 

 look optically hyaline, sec Negri Bodies. 

 Maceration (L. macerare, to soak) is a very 

 important technique by which tissues 

 are soaked for considerable periods of 

 time in various fluids which loosen the 

 connections between the cells and allow 

 them to be easily separated for micro- 

 scopic study. This is a method em- 

 ployed by the great masters in histology 

 which is unfortunately not sufficiently 

 used now-a-days. 



For nervous tissue Addison (McClung, 

 p. 439) recommends Gage's dissociator 

 which is 2 cc. formalin in 1000 cc. 

 physiological salt solution for 2 or 3 

 days. After this treatment large ven- 

 tral horn nerve cells can easily be dis- 

 sected out with the aid of a binocular 

 microscope, stained with carmine, picro- 

 carmine or a dilute anilin dye and 

 viewed as units with parts of their 

 processes attached. 



Smooth muscle of the bladder is well 

 dissociated bv 10-20% nitric acid 

 (Dahlgren, in McClung, p. 423). The 

 resulting fibers are suitable for class use. 



Thyroid follicles are freed from the 

 surrounding tissue and can be examined 

 individually after maceration in cone, 

 hydrochloric acid 3 parts and aq. dest. 

 1 part for about 24 hrs. and thorough 

 washing in at least 10 changes of tap 

 water (Jackson, J. L., Anat. Rec, 1931, 

 48, 219-239). 



Epidermis can be separated from 

 dermis by maceration in 1% acetic acid, 

 see epidermis. 



Kidney tubules. Pieces of kidney 

 fixed in 10% formalin or in Kaiserling's 

 solution are placed in cone, hydrochloric 

 acid at room temperature until they 

 become sufficiently softened after 2-7 

 days. The time depends upon size of 

 piece, degree of fibrosis and other factors. 

 There is no advantage in using fresh 

 tissue. When adequately macerated 

 the almost diffluent tissue is washed in 

 repeated changes of aq. dest. in which 

 it may be kept for several days. Dis- 

 sect out individual tubules with the 

 aid of a binocular microscope (Oliver, 

 J. and Luey, A. S., Arch. Path., 1934, 

 18, 777-816). 



Seminiferous tubules. Whole human 

 testicles are fixed in formalin. They 

 are then cut into segments 1 cm. thick 

 parallel to direction of the lobules. The 

 tunica vaginalis is not removed but is 

 slit through in one or two places with a 



