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Biomedical subjects

P Isaacson

Publications and source records attributed to P Isaacson.

64 records · Page 4Linked to original sources
PubMed1977

Immunohistochemistry of carcinoembryonic antigen: characterisation of cross-reactions with other glycoproteins.

In the course of demonstrating carcinoembryonic antigen (CEA) in normal human small intestine cross-reactivity of specific antiserum against red blood cells, vascular endothelium, and Paneth cell granules was noted. Pretreatment of sections with periodic acid eliminated these cross-reactions without affecting the staining of CEA, indicating that the antigenic determinants shared between CEA and other glycoproteins are in the carbohydrate portion of the molecules. These findings emphasise the caution with which immunohistochemical results should be regarded even when they are apparently well controlled.

Carcinoembryonic Antigen↗
PubMed1977

Carcinoembryonic antigen (CEA) in the normal human small intestine: a light and electron microscopic study.

An immunoperoxidase method for the demonstration of carcinoembryonic antigen (CEA) in tissues was applied to formalin-fixed paraffin embedded and glutaraldehyde-fixed resin sections of normal human small intestine. CEA could easily be demonstrated coating the surface of the small intestine, lining the crypts, and in goblet cells, indicating its presence there in considerable concentration. At the ultrastructural level CEA was localised in the glycocalyx and in mucin granules of goblet cells but not intracytoplasmically.

Carcinoembryonic Antigen↗
PubMed1976

The demonstration of carcinoembryonic antigen in colorectal carcinoma and colonic polyps using an immunoperoxidase technique.

Carcinoembryonic antigen (CEA) has been demonstrated in tissues, by immunofluorescence, with conflicting results. Originally thought to be persent in colorectal carcinoma only, the antigen was later demonstrated in inflamed colonic mucosa and polyps. Using formalin-fixed, paraffin-embedded tissues and an immunoperoxidase technique, we have attempted to demonstrate CEA in 12 colorectal carcinomas, in adjacent benign mucosa, and in 42 polyps of varying histologic type. CEA was demonstrated in all colorectal cancers but not in adjacent inflamed mucosa. The antigen could not be demonstrated in polyps except in five cases where CEA was shown in morphologically atypical glands only. With out technique, the demonstration of CEA is a reliable indicator of malignant change in colonic mucosa. The findings in polyps tend to support the concept of carcinoma in situ in adenomatous polyps and the polyp-cancer sequence.

Adenocarcinoma↗
PubMed1976

Mast cells in benign nerve sheath tumours.

The concentration of mast cells was estimated, and their distribution noted, in 132 benign nerve sheath tumours. With few exceptions, neurofibromas were characterised by a high concentration of diffusely distributed mast cells. In neurilemmomas fewer mast cells were present and these were restricted to Antoni type-B tissue. Based on these observations, and on the behaviour of mast cells in injured nerves, it is postulated that neurilemmomas are true neoplasms of Schwann cells sometimes incorporating reactive endoneurial tissue (Antoni type-B tissue). Neurofibromas probably consist of reactive endoneurial tissue and may not be true neoplasms. The distinction between neurofibromas and neurilemmomas thus seems to be a real one based on a difference in histogenesis.

Cell Count↗
PubMed1976

Tissue demonstration of carcinoembryonic antigen (CEA) in ulcerative colitis.

An immunoperoxidase technique was used to demonstrate carcinoembryonic antigen (CEA) in sections of proctocolectomy specimens from nine cases of ulcerative colitis in some of which carcinoma and premalignant change had developed. Carcinoma and premalignant change stained positively for CEA in contrast with benign mucosa, whether or not inflammatory dysplasia was present.

Adult↗
PubMed1972

International standards and international reference preparations: amphotericin B, vancomycin, capreomycin, cefalotin, demethylchlortetracycline, gentamycin, gramicidin S, kanamycin and kanamycin B, lincomycin, lymecycline, methacycline, paromomycin, rifamycin SV, ristocetin and ristocetin B, spiramycin, and triacetyloleandomycin.

Each of the preparations described here was obtained and evaluated at the request of a WHO Expert Committee on Biological Standardization. Unless otherwise stated, a standard procedure was used to distribute the material into individual ampoules. The procedure was as follows. Upon receipt by the National Institute for Medical Research (NIMR), London, materials were stored temporarily in the dark at a temperature of -10 degrees C or lower, and protected from moisture. At a convenient time they were brought back to room temperature, mixed, and distributed into individual neutral glass ampoules so that each ampoule contained 50-100 mg of powder. If it was known that the material was light-sensitive non-actinic glass ampoules were used. After exhaustive drying in vacuum over phosphorus(V) oxide, the ampoules were either constricted (up to 1963) or fitted with capillary leak plugs, dried for a further period under the same conditions, filled with dry nitrogen, and sealed by fusion of the glass. The total drying period varied from 8 to 38 days according to the nature of the material. After they had been tested for leaks, the ampoules were stored in the dark at -20 degrees C.

Amphotericin B↗