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B L Mepham

Publications and source records attributed to B L Mepham.

10 recordsLinked to original sources
PubMed1997

Tissue preparation for immunocytochemistry.

AIMS: To investigate the effect of tissue preparation on immunostaining and to establish whether there is a standard tissue preparation schedule that allows optimal demonstration of all antigens. METHODS: Blocks of tonsil were subjected to variations to a standard fixation, processing, and section preparation schedule. The sections were stained with five antibodies-L26 (CD20), UCHL1 (CD45RO), CD3, vimentin, and anti-kappa light chain--using the streptavidinbiotin immunostaining technique. When further investigation was necessary, other tissues and antibodies were used and where weak immunostaining was obtained the use of microwave pretreatment to improve staining was tested. RESULTS: Several factors involved in fixation were found to affect immunoreactivity. These included the duration, pH, and type of fixative used. In tissue processing only temperature and the duration of the dehydration and wax infiltration steps affected immunoreactivity. Of all the factors investigated, the temperature and duration of the section drying had the greatest effect. In contrast, long term storage of cut sections before immunostaining had no effect on the reactivity of the antibodies tested. Antibodies were found to be affected by alterations to tissue preparation by varying degrees, UCHL1 and vimentin being the most susceptible to changes in fixation and L26 to changes in processing. Where weak staining occurred, microwave pretreatment was generally found to eliminate the problem. CONCLUSIONS: There is no standard tissue preparation schedule for the optimal demonstration of all antigens. Factors involved in all aspects of tissue preparation can affect immunoreactivity, so it is important that precise details of the preparation schedule are given when reporting immunocytochemical studies, rather than using the general term "routinely fixed and processed".

Histocytological Preparation Techniques↗
PubMed1982

Influence of fixatives on the immunoreactivity of paraffin sections.

The unlabeled antibody peroxidase-antiperoxidase (PAP) technique was used to demonstrate IgA in paraffin sections of human tonsil fixed in eight commonly known fixatives. In all but one of the fixatives, treatment with trypsin prior to immunostaining resulted either in digestion of sections, or no change in positive staining. In tissues fixed in neutral buffered formalin-saline, positive staining was absent unless the sections had been treated with trypsin, and it has been shown that digestion requirements of different areas throughout a section may vary according to the effectiveness of fixation.

Formaldehyde↗
PubMed1982

Immunoperoxidase techniques in human renal biopsy.

Immunoperoxidase techniques can be easily performed on formalin fixed renal tissue after incubation in trypsin. The sensitivity of the PAP technique on fixed tissue is as good as immunofluorescence methods using frozen sections. The method provides permanent preparations with clear localization of deposited immunoproteins giving accurate classification of renal disease and assessment for treatment. The availability of this technique for retrospective and centralized studies is a major advantage. Infectious agents are rendered harmless and can be specifically identified. The development of the trypsin-immunoperoxidase technique is an important and exciting advance in renal immunopathology.

Antigens↗
PubMed1979

Primary gastrointestinal lymphomas: a classification of 66 cases.

Using routine histology, resin embedded sections and immunohistochemical techniques on formalin-fixed, paraffin processed tissue, 66 cases of primary gastrointestinal lymphoma have been classified. This study necessitated the development of reliable criteria to separate lymphomas of true histiocytic origin from those of lymphocytic origin. Among the morphologic properties of malignant histiocytes were complex pleomorphic nuclei, abundant well delineated cytoplasm and phagocytosis. These cells were shown to contain all major immunoglobulin chains, C3, lysozyme and in some cases alpha 1 antitrypsin. Malignant lymphomas derived from histiocytes could be divided into two groups: malignant histiocytosis of the intestine (MHI), a recently described diffuse pleomorphic lymphoma associated with villous atrophy of the small intestine, and histiocytic lymphoma (HL) which forms solid tumor masses in a similar manner to lymphocyte derived tumors. Immunohistochemical studies of lymphocyte derived tumors were negative apart from one case with plasmacytoid differentiation. Of the 66 cases, 50% were of histiocytic origin (33% MHI, 17% HL) and 41% of lymphocyte origin, there was one case of Hodgkin's disease and five cases were unclassified. The role of the histiocyte in gastrointestinal mucosa deserves further study.

Gastrointestinal Neoplasms↗
PubMed1979

The use of proteolytic enzymes to improve immunoglobulin staining by the PAP technique.

Proteolytic enzymes, protease and trypsin have recently been introduced to reduce the inconsistency hitherto encountered in the unlabelled antibody--enzyme method using PAP. This study investigated factors determining the optimum conditions for use of such enzymes in order to establish which one is most suitable. Trypsin was the most effective enzyme; however, its activity decreased over 3 h, a feature paralleled immunocytochemically. Method and duration of fixation appears to influence the required time of exposure to trypsin in order that consistent immunostaining may be produced. Treatment of sections with trypsin prior to the use of the unlabelled antibody--enzyme method using PAP renders the technique reliable, provided the enzyme is used in a carefully controlled manner.

Humans↗
PubMed1978

Plasma cell granuloma of the stomach.

A case of plasma cell granuloma of the stomach is described, only one similar case having been previously recorded. Differentiation from a neoplastic plasmacytoma was achieved by demonstrating the polyclonal nature of the plasma cells using an immunoperoxidase technique.

Gastrectomy↗
PubMed1978

Immunopathology of angioimmunoblastic lymphadenopathy.

Eight patients with angioimmunoblastic lymphadenopathy have been studied by a variety of immunological and pathological techniques. They exhibited a spectrum of immunological reactivities that, in this small series, could be roughly correlated with survival. Those patients with relative B-cell predominance as shown by cell marker studies, histologically showed large numbers of plasma cells, and this pattern was associated in 3 of our patients with a survival of 3 years or more. T-cell predominance or both B- and T-cell depletion was associated histologically with large numbers of blast cells and eosinophils, but with few plasma cells. These patients responded poorly to therapy and had short survival times. One patient with B-cell predominance subsequently died of a histiocytic lymphoma.

Adult↗