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Biomedical subjects

A Carmichael

Publications and source records attributed to A Carmichael.

5 recordsLinked to original sources
PubMed1992

A novel tissue preservation medium for immunoperoxidase staining of skin biopsies.

The requirement for unfixed tissue is a major drawback in the use of immunohistochemistry for the diagnosis of inflammatory and neoplastic disease. We describe the use of a novel gel transport medium (U.K. Patent No. WO 90/07703, international patent applications pending) to preserve unfixed skin biopsies from allergic contact dermatitis reactions for 1 week prior to frozen section and immunohistochemistry for leucocyte antigens. The medium can be used with biopsies up to 6 mm3 and does not require any alteration in the usual frozen section or immunohistochemical staining procedures. The results show a subjective improvement in both morphology and staining quality. We believe this to be due to improved cutting of the sections and reduced background staining of collagen. This transport medium should be of considerable benefit to the provision of a clinical service, because it allows tissue for immunohistochemical examination to be taken at locations distant from the pathology laboratory.

Cryopreservation↗
PubMed1992

Preservation of keratin expression in oral mucosa using a novel transport medium.

Cellular expression of keratins (intermediate filaments) can be demonstrated by immunocytochemistry using unfixed tissue. However, for practical reasons, provision of fresh tissue to the laboratory is often difficult. Recently a fresh tissue transport medium (Patent applied for) has been developed which allows keratin immunocytochemistry to be performed up to 4 days after biopsy. In this study oral mucosal biopsies from 10 patients were hemisected, half placed in the new transport medium at 4 degrees C and the other half immediately frozen in liquid nitrogen. After 4 days frozen sections of both halves of the biopsies were stained by immunocytochemistry using various antikeratin antibodies. The morphology and staining characteristics of the two halves of the biopsies were then assessed. No significant difference could be found in either morphology or preservation of keratin expression in specimens stored in transport medium, as compared to those in liquid nitrogen. This new transport medium may offer considerable advantage for the provision of a histologic and immunocytochemical diagnostic service.

Cacodylic Acid↗
PubMed1992

Immunohistochemical demonstration of B and T-lymphocyte cell surface markers: an assessment of tissue transport/storage media.

A number of solutions were tested on lymphoid tissue with a view to devising a tissue transport/long-term storage medium which would preserve the morphology and antigenicity of lymphocytes, for demonstration of B- and T-cell surface markers using monoclonal antibodies. Some of the solutions produced total loss of any recognisable tissue structure, but one newly-devised medium gave excellent preservation of morphology and nuclear detail, together with extremely good monoclonal antibody staining. This sterilised medium, Carmichael's medium*, contains a buffer and cryoprotectant: it forms a gel at 4 degrees C, but it is easily liquefied in warm water just prior to immersion of the biopsy. Sections from tissue preserved in Carmichael's Medium were found to be of equally good quality as, and in some cases better than, those which had been fresh frozen. *International patents are currently pending on the formulation of this medium, which will be available commercially through Raymond Lamb Ltd, London, England, UK.

Antigens, Surface↗
PubMed1977

13q- syndrome. Family study.

A patient is described who had a deletion involving the long arm of chromosome number 13. The mother and 4 of 7 living sibs showed a balanced translocation from the long arm of a number 13 chromosome to the long arm of a number 3 chromosome. We stress the importance of investigating the families of children with chromosomal defects.

Abnormalities, Multiple↗