ENDAMOEBA 



116 



ENTEROCHROMAFFIN CELLS 



one week in a refrigerator at a tempera- 

 ture of 1° C. Decalcification of dentin 

 is completed by placing the bag in 

 5% trichloroacetic acid. Not more 

 than two weeks should be required. 

 Washing and dehydration in ethyl alco- 

 hol and butyl alcohol is carefully ac- 

 complished with tooth still in the bag. 

 Imbed in paraffin, section and stain by 

 ordinary methods. Constant pressure 

 during decalcification may further im- 

 prove results (Sognnaes, R. F., J. Den- 

 tal Res., 1948, 27, 609-622). 



4. Cape-Kitchin celloidin decalcifica- 

 tion method. Cut DuPont's parlodion 

 into small cubes and dissolve in acetone 

 free methyl alcohol making thick solu- 

 tion. To 200 cc. add 90 cc. methyl 

 alcohol constantly stirring and 9 cc. 

 nitric acid, sp. gr. 1.42. Follow decalci- 

 fication of enamel in this mixture be- 

 tween crossed nicols of polarizing micro- 

 scope with 24 mm. objective. Double 

 refraction disappears with decalcifica- 

 tion (Bodecker, C. F., J. Dent. Res., 

 1937, 16, 143-150). 



5. Permeability. When the apex of a 

 tooth is immersed in strong alcoholic 

 solution of fuchsin -f NaCl the enamel 

 becomes stained (v. Beust, T., Dental 

 Cosmos, 1912, 54, 659). Another way 

 is to test for penetration of lead, boron 

 and other easily recognizable chemicals 

 (Howe, P. R., Dental Cosmos, 1926, 68, 

 1021-1033). After intraperitoneal in- 

 jections of trypan blue blue coloration 

 can be observed in developing enamel 

 only (not adult) as well as in dentin of 

 dogs (Gies, W. J., J. Nat. Dent. Assoc, 

 1918, 5, 529-531). Marshall (J. S., J. 

 Dent. Res., 1921, 3, 241-255) employed 

 Naphthamine brilliant blue similarly 

 as a vital stain. See Dentin, vital 

 staining. A "Triple Embedding" tech- 

 nique is described by Brain, E. B., J. 

 Roy. Micr. Soc, 1950, 70, 313-316. 



Endamoeba, see Entameba. 



Endocervical Smears, see Papanicolaou 

 Techniques. 



Endolymph. To demonstrate its circulation 

 employ method used by Guild, S. R., 

 Am. J. Anat., 1927,39, 57-81. Introduce 

 solution of potassium ferrocyanide and 

 iron ammonium citrate into cochlear 

 ducts of living guinea pigs under anes- 

 thesia. Kill at intervals up to 48 hrs. 

 Excise tissue and fix in acid fluid which 

 precipitates Prussian Blue wherever 

 the solution has circulated. 



Endometrial Smears, see Papanicolaou 

 Techniques. 



Endospore stain for bacteria in blood smears. 

 Smear, air dry and fix by flaming 3 times. 

 5% aq. malachite green 5 min., wash in 

 tap water 10-20 sec. 0.5% aq. safranin, 

 10 sec, wash quickly, dry and examine 



(Bruner, D. W. and Edwards, P. R., 

 3. Lab. & Clin. Med., 1939, 25, 543-544). 



Enrichment techniques, see Concentration. 



Entameba. Craig (p. 35) gives a useful 

 table of diagnostic features of intestinal 

 amebae in man; also, on p. 55, a list of 

 objects that may be mistaken for 

 amebae in unstained and stained prepa- 

 rations; and details as to media for cul- 

 tivation of which the Boeck and Doboh- 

 lav media and the simpler Craig media 

 are the most helpful. 



This genus includes E. histolytica, 

 the cause of amebic dysentery and E. 

 coli and E. gingivalis, two apparently 

 harmless commensals. The technique 

 is essentially the same for all three. 

 In searching for E. histolytica or E. coli 

 take a small amount of fresh feces, mix 

 with physiological saline solution and 

 examine directly. Recognize amebae 

 by large size and movements if slide 

 is kept warm. E. histolytica frequently 

 contains erythrocytes. Mallory (p. 

 296) advises mixture with Gram's 

 Iodine solution to demonstrate glycogen 

 if present, or mixing with drop 1-2% 

 formalin, then treatment with drop 2% 

 acetic acid and coloration with 1 drop 

 1% aq. neutral red. E. gingivalis is to 

 be found in decayed teeth. Only E. 

 histolytica extensively invades tissues. 



1. To make permanent smear prepara- 

 tions (Mallory, p. 296) fix thin smear 

 while moist in 95% alcohol, 1 part, and 

 sat. aq. corrosive sublimate, 2 parts, 

 for 15 min. Wash for few sec. in water 

 and cover with 1% alcoholic iodine for 

 3 min. Wash in aq. dest. until iodine 

 color is extracted. Wash again and stain 

 with Phosphotungstic Acid Hema- 

 toxylin, 30 min. Wash in water, dehy- 

 drate in 95 and abs. alcohol, clear in xylol 

 and mount in balsam. Nuclei and ecto- 

 sarc, deep blue; cytoplasm, bluish. 



2. To stain differentially in sections 

 (Mallory, p. 297). Fix in 95% or abs. 

 ale, and make paraffin or celloidin sec- 

 tions. Stain in 0.25% aq. thionin 3-5 

 min. Differentiate in 2% aq. oxalic 

 acid, i-1 min. After washing in water, 

 dehydrate in 95% and abs. ale Clear 

 in xylol and mount in balsam, except for 

 celloidin sections which require clearing 

 in terpineol, or origanum oil, after 95% 

 ale. Nuclei of amebae brownish red, 

 those of all other cells, blue. See 

 lodine-Eosin stain and Walker's 

 Method. 



Enterochromaffin Cells. Perhaps the best 

 technique is Bodian's protargol method 

 as described by Dawson, A. B. and 

 Barnett, Julia, Stain Techn., 1944, 19, 

 115-118. For the influence of pilo- 

 carpin on enterochromaffin cells see 

 Hamperl, II., Ztschr. f. Mikr. Anat. 



