David:

Entamoeba histolytica (Amoeba dysenteriae) occurs in the epithelial tissues
of the colon, causing ulceration(amebic dysentery); in a proportion of
cases, the organism may reach the liver via the bloodstream and produce
hepatic amebiasis; occasionally spreading to other organs, such as brain,
kidney and lungs.

The organisms are faintly hematoxyphilic and will be visible using the
Heidenhain's iron hematoxylin technique appearing black. I have also stained
them using Weigert's iron hematoxylin, they will be brown-black.

Because of their high glycogen content, they are also visible using the
Best's Carmine or the McManus periodic-acid Schiff techniques. The organisms
will stain red.

They can also be demonstrated using the Gridley's method, that is specific
for entamoeba histolytica. This procedure does not stain amoeba
differentially, but is useful in that it demonstrates the ingested
erythrocytes within the amoeba a deep rose. It is possible that the stain
that appears to you as a faded Trichrome is really a Gridley's. It employs
the use of Aniline-Eosin and Naphthol Green B and could easily be
interpreted as a faded Masson Trichrome.

Last but not least, the organisms are visible using the Mallory's
phosphotungstic acid hematoxylin technique. They will appear blue. This
method does require phosphotungstic acid hematoxylin which takes 4 months to
ripen.

My choices would be a PAS and a Heidenhain's iron hematoxylin. If you would
like a faxed copy of any of the above mentioned techniques, I would be glad
to fax them to you.

Eric Kellar
Histology/Immunohistochemistry
University of Pittsburgh Medical Center





	----------
	From:  drichter@webtv.net [SMTP:drichter@webtv.net]
	Sent:  Saturday, October 24, 1998 9:19 AM
	To:  HistoNet@Pathology.swmed.edu
	Subject:  Stain for Entamoeba histolytica.

	Greetings from, in the words of the histonet server, "a hospital
	employee from an obscure locale". I have been a wallflower for
several
	weeks reading the digest and thought I might now be able to use your
	resources.

	I have a surgical colon specimen from a patient that the pathologist
	wishes to test for E. histolytica. What stain or stains do you think
	would be the best for me to run? I have a control that was obtained
from
	the CDC a very long time ago and the stain is so faded it is no
longer
	recognizable. My guess is it was some type of trichrome.

	David B. Richter HT
	Weeks Memorial Hospital
	Lancaster, NH