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D Y Mason

Publications and source records attributed to D Y Mason.

At least 289 records · Page 16Linked to original sources
PubMed1982

Ultrastructural localization of human complement C3b receptors in the human kidney as determined by immunoperoxidase staining with the monoclonal antibody C3RTo5.

The precise localization of human complement C3b receptors in human kidneys was investigated by means of indirect immunoperoxidase staining of frozen kidney sections with the monoclonal antibody C3RT05, which is specific for human C3b receptors. Transmission electron microscopy indicated that C3b receptors are located on the entire cell membrane of the visceral epithelial cells of the glomeruli.

Antibodies, Monoclonal↗
PubMed1982

Diffuse follicular lymphoid hyperplasia of the small intestine without primary immunoglobulin deficiency.

Three cases of follicular lymphoid hyperplasia extending to the whole length of small intestine are reported in three young adult patients of low economic status. The disease was revealed by chronic diarrhea with malabsorption and/or protein-losing enteropathy. In one patient, all transitional patterns were found between the hyperplastic follicles and a small intestinal multicentric centrocytic-centroblastic lymphoma. No abnormalities in humoral or cellular immunity were found in the three patients. In particular, serum immunoglobulins (except IgG in one case) and plasma cell populations of small intestinal lamina propria were normal. Diffuse follicular lymphoid hyperplasia of the small intestine in the absence of primary immunoglobulin deficiency appears to be a rare condition associated with (or leading to) intestinal malignant lymphoma in most cases. Patients usually belong to the same populations as those suffering from alpha-chain disease.

Adolescent↗
PubMed1982

The value of immunohistological screening in the production of monoclonal antibodies.

This paper describes an immunoperoxidase technique for labelling cryostat tissue sections which is routinely used in the authors' laboratories both in the initial screening of hybridoma culture supernatants, and also during the subsequent cloning and growth of antibody-secreting cell lines. The technique can readily be performed on 100 samples in less than 3 h and is free of non-specific background labelling. The staining pattern of a monoclonal antibody on a single tissue section allows semiquantitative assessment of its reactivity against a wide variety of tissue constituents and is thus inherently much more informative than conventional screening techniques (such as binding assays) which yield only a single numerical value for each test performed. In consequence it is often possible to identify the probable specificity of a new monoclonal antibody at the primary screening stage. A further important advantage of immunohistological screening is that it detects antigens on cells or other tissue structures which do not readily enter suspension and also antibodies against nuclear and cytoplasmic antigens. Examples of monoclonal antibodies analysed by immunohistological screening include antibodies against C3b receptor, HLA-DR, factor VIII-related antigen, human syncytiotrophoblast, dendritic reticulum cells and a proliferation-associated cell surface glycoprotein.

Animals↗
PubMed1982

Use of monoclonal antibodies for the histopathological diagnosis of human malignancy.

This paper describes the use of a panel of seven monoclonal antibodies (selected so as to include reagents reactive with both epithelial and lymphoid cells) for distinguishing between anaplastic carcinoma and high grade lymphoma. Details are given of the immunohistological reactions of these antibodies against a wide range of both normal and malignant tissues and of a number of practical instances in which use of the antibody panel enabled a diagnosis to be made when routine histological examination had been inconclusive.

Adult↗
PubMed1982

Preparation of peroxidase: antiperoxidase (PAP) complexes for immunohistological labeling of monoclonal antibodies.

The production of mouse peroxidase:antiperoxidase (PAP) complexes suitable for immunohistological use in conjunction with monoclonal antibodies is described. Three approaches were explored: 1) production of conventional polyclonal PAP complexes; 2) conversion of rabbit PAP to "pseudo-mouse PAP" by incubation with monoclonal mouse anti-rabbit immunoglobulin; 3) formation of PAP complexes from monoclonal mouse antiperoxidase. PAP complexes prepared by the latter technique gave the best immunohistological labeling reactions, being stable on storage and compatible with a wide range of human monoclonal antibodies. Gel filtration revealed that monoclonal PAP is of lower molecular weight than conventional PAP complexes (fulfilling theoretical predictions based on the monospecificity of monoclonal antibodies).

Animals↗
PubMed1982

Human complement (C3b) receptors defined by a mouse monoclonal antibody.

The aim of the present study was to prepare a monoclonal antibody against human C3 receptors. The monoclonal antibody termed C3RTo5, which is characterized in this study, inhibited the ligand binding of C3b receptors of human erythrocytes, neutrophils and lymphocytes, but did not block the ligand binding of C3bi and C3d receptors. C3RTo5 reacted only with cells that express C3b receptors. It did not react with cells that do not express C3 receptors or with cells that express C3 receptors other than C3b receptors. The reactivity of C3RT05 against C3b receptors of human erythrocytes, neutrophils, glomerular cells, tonsil cells, or spleen cells could be removed by absorption with human erythrocytes or tonsil cells, whereas absorption with human peripheral T cells or sheep erythrocytes had no effect. In immunoprecipitation studies, a glycoprotein with a mol. wt of 205,000 could be isolated with C3RTo5 from non-ionic detergent lysate of tritiated tonsil cells. A rabbit antiserum prepared against this glycoprotein was able to stain C3b receptor-positive cells, inhibit C3b receptor ligand-binding activity and, furthermore, to precipitate a 205,000 mol. wt component. The results of this study indicate that C3RTo5 is a monoclonal antibody with selective reactivity to C3b receptors and presumably to the binding sites within the receptor molecule. Using C3RTo5 further strong evidence was obtained that membrane-bound C3b receptors have a mol. wt of 205,000.

Animals↗
PubMed1981

Immunohistological analysis of human lymphoid tissue by double immunoenzymatic labelling.

The increasing number of antigens detectable in human lymphoid tissue (particularly since the advent of monoclonal antibodies) makes it necessary to have techniques available for studying the relative distribution patterns of pairs of antigens in tissue sections. Double immunoenzymatic labelling (using peroxidase and alkaline phosphatase) offers a number of advantages over double immunofluorescence, including the fact that the two antigens can be visualised simultaneously (rather than sequentially) and that the labels are permanent. In studying paraffin-embedded human lymphoid tissue an important application of the double immunoenzymatic technique lies in distinguishing Ig-positive cells containing exogenous Ig (which stain for only a single light chain class). In addition double staining of paraffin sections for IgG and IgM has been used to show that "switch" cells containing both these classes of heavy chain are rare in reactive lymphoid tissue. The potential scope of the double immunoenzymatic technique has been extended by showing that the procedure is applicable to cryostat sections (in which antigenic reactivity is better preserved than in paraffin sections) and by adapting it for use with monoclonal antibodies (by preparing "monoclonal PAP" complexes).

Antigens↗
PubMed1981

The expression of major histocompatibility antigens by human chorionic villi.

Frozen sections of human placentae taken at selected stages throughout gestation were stained with monoclonal antibodies to HLA-A, B, C and DR antigens, using an indirect immunoperoxidase technique. No staining of villous trophoblastic tissue was detected. Antibody to HLA-A, B, and C antigens clearly stained membranous elements of the villous stroma. Antibody to HLA-DR antigens stained rare, elongated cells of the villous stroma in the term placenta. Monoclonal antibodies to syncytiotrophoblast membrane were used as a control. This antigen distribution was confirmed by absorption of these monoclonal antibodies in an indirect radioimmunoassay. Adult spleen homogenate gave much stronger absorption than a trophoblast membrane preparation with antibodies to HLA-A, B, C or DR antigens. The opposite absorption pattern was observed with the anti-trophoblast monoclonal antibodies. Detergent solubilisation did not affect the absorption capacity of trophoblast membrane for HLA-A, B, C or DR antigens. Maternal antibody could be eluted from trophoblastic areas of term placental sections by washing at physiological pH, but this did not effect the binding of monoclonal antibodies. Thus the HLA antigens were not masked by preformed maternal alloantibody. These observations confirm that chorionic villous trophoblast does not express detectable HLA antigen. This may be the principal reason for the lack of rejection of the fetal allograft.

Absorption↗
PubMed1981

Monoclonal antibody to human platelet glycoprotein I. I. Immunological studies.

A monoclonal hybridoma antibody specific for platelet glycoprotein I complex is described. The nature od the antigen was determined by demonstration that it was chymotrypsin sensitive and gave a peak at 150 000 daltons on SDS-PAGE after immunoprecipitation. The expression of the antigen is restricted to platelets and megakaryocytes with at least 1.6 x 10(4) molecules of antigen per platelet. The antibody failed to bind to platelets from patients with Bernard Soulier syndrome, where there is known to be a deficiency of glycoprotein Ib/Is expression. Binding to platelets from patients with Glanzmann's thrombasthenia was normal.

Animals↗
PubMed1981

Reactive and neoplastic human lymphoid cells producing J chain in the absence of immunoglobulin: evidence for the existence of 'J chain disease'?

The initiation of cytoplasmic Ig synthesis in differentiating B cells is accompanied by the start of cytoplasmic J chain production. As the cell matures further, J chain synthesis ceases (unless it is producing dimeric IgA or 19S IgM). In consequence, it is common to find Ig-positive, J chain-negative cells in reactive lymphoid tissue. However, the reverse pattern (Ig-negative/J chain-positive), which would indicate J chain production unaccompanied by Ig synthesis, has not been reported. In this paper we describe the detection of such cells in reactive human lymphoid tissue by a double immunoenzymatic labelling technique. Furthermore, retrospective immunohistological analysis of 90 cases of human high-grade lymphoma revealed three cases in which the neoplastic cells appeared to synthesize J chain but not Ig. These findings suggest that the term J chain disease might be introduced to describe this new class of lymphoid neoplasm. However, it is pointed out that immunochemical categories of human B lymphoproliferative diseases based upon patterns of Ig synthesis are often in direct conflict with histological categories (cf. mu chain-producing neoplasms) and the term J chain disease cannot therefore be recommended. It is probable that further cases of J chain-positive, Ig-negative lymphoid neoplasms, covering a range of histological categories, will be described in the future.

Adult↗
PubMed1980

Serum proteins in human squamous epithelium.

A new immunoperoxidase staining technique of high specificity (the labelled antigen method) has been used for the detection of serum proteins in the epithelium of human skin and mucous membranes. The majority of specimens contain cells showing strong diffuse intracellular staining. These cells usually lie in the upper mid-zone of the epithelium and are often characterized by vacuolated or pyknotic nuclei. Double immunoenzymatic labelling (using alkaline phosphatase and peroxidase) showed that the different proteins are usually present in the same cells. A less frequent pattern of staining took the form of delicate strands of intercellular IgG. Samples from a wide range of skin diseases were studied, but no clear relationship between positive epithelial staining and disease states was apparent. It is suggested that serum proteins may enter epithelial cells by passive diffusion, and attention is drawn to other instances (e.g. in the central nervous system and lymphoid tissue) where similar phenomena have been observed by immunoenzymatic staining techniques.

Blood Proteins↗
PubMed1980

Immunoperoxidase staining of surface and intracellular immunoglobulin in human neoplastic lymphoid cells.

An immunoperoxidase technique for the optical microscopic detection of cellular immunoglobulin has been used to stain fixed smears of human neoplastic B lymphoid cells. Only four out of 28 cases of chronic lymphatic leukaemia (CLL) showed membrane labelling by this technique. In contrast, when 14 samples from other types of B lymphoproliferative disorder (including hairy cell leukaemia, non-Hodgkin's lymphoma, and prolymphocytic leukaemia) were studied, all samples showed membrane immunoglobulin labelling (confirmed by capping experiments). This discrepancy was attributed to the greater density of surface immunoglobulin present on neoplastic cells in the latter group of disorders compared to CLL. This immunoperoxidase technique is therefore less sensitive than immunofluorescent staining of cells in suspension for the demonstration of neoplastic cell surface immunoglobulin. However, it offers a number of advantages (eg, excellent visualisation of cell morphology, permanence of stained preparations, and applicability to stored samples) which recommend it as the method of choice in certain clinical haematological contexts.

B-Lymphocytes↗
PubMed1980

Technical aspects of lymphoma immunohistology.

Immunohistological techniques (i.e., based on tissue sections) for the study of human lymphoma have been developed in recent years as alternatives to immunocytochemical methods (based on cell suspensions). These techniques not only allow the important architectural features of the lymphoma sample to be preserved, but are also more convenient to use in that tissues can be processed rapidly and studied at leisure. The relative advantages and disadvantages of frozen versus fixed embedded tissue, and of immunofluorescence versus immunoenzymatic methods are reviewed, and technical aspects of proteolytic digestion (as a technique for enhancing immunohistochemical labeling) are discussed. This review concludes with a consideration of the problems encountered in the interpretation of immunohistochemical labeling for lymphoma cell immunoglobulin in paraffin sections.

Histocytochemistry↗
PubMed1980

Lactoferrin deficiency as a consequence of a lack of specific granules in neutrophils from a patient with recurrent infections. Detection by immunoperoxidase staining for lactoferrin and cytochemical electron microscopy.

Neutrophils from a boy suffering from recurrent infections were found to be totally deficient in specific granules when studied by electron microscopy. In contrast, myeloperoxidase-containing azurophil granules were increased in number. This deficiency of specific granules could be detected at the light-microscopic level using an immunocytochemical technique to demonstrate the absence of lactoferrin. Neutrophils also exhibited abnormal nuclear segmentation, nuclear clefts, an abnormally weak cytochemical reaction for alkaline phosphatase, and an increased number of mitochondria and ribosomes. Some granulocytic precursors were abnormal, and many of these cells were phagocytosed by macrophages in the bone marrow. Despite these multiple abnormalities and the history of severe pyogenic infection, the in vitro bactericidal capacity of the neutrophils was within normal limits, and normal degranulation of azurophil granules occurred following phagocytosis. The precise mechanism by which the deficiency of specific granules in this patient led to an enhanced in vivo susceptibility to infection therefore remains obscure. However, attention is drawn to the fact that in three previously described cases of specific granule deficiency a history of recurrent infections was present.

Bacterial Infections↗
PubMed1980

An immunohistological study of human lymphoma.

In this study the problems encountered in staining immunoglobulin (Ig) in sections of paraffin-embedded human lymphoma samples have been investigated. It was found that the "masking' of cytoplasmic Ig, which occurs when tissues are fixed in formol saline (the fixative employed in most previous studies), can be avoided by the use of mercury-based fixatives. When non-Hodgkin's lymphoma samples fixed in this way were studied it was found that cytoplasmic Ig labelling of both lymphoid and histiocytic cells is often attributable to non-specific uptake of serum proteins. This phenomenon probably accounts for a number of published anomalous immunoperoxidase staining results in human lymphoma (e.g. the presence of both kappa and lambda chains in the same neoplastic cell). Double immunoenzymatic labelling (using alkaline phosphatase and peroxidase) proved valuable in the elucidation of this phenomenon. When staining due to absorbed Ig was discounted it was possible to demonstrate monoclonal Ig labelling in seven out of sixteen cases of non-Hodgkin's lymphoma. In each case IgM was found in association with a single light chain type and these results were in agreement with those obtained by direct immunofluorescent labelling of cryostat sections. In a further case u chains without associated light chains were demonstrated by immunoperoxidase staining. Seven cases of Hodgkin's disease were studied by immunoenzymatic techniques. Although IgG was frequently found in Reed-Sternberg and Hodgkin's cells its presence was not attributable to non-specific uptake of serum protein since albumin was absent or only present in small amounts. These findings are in support of the macrophage origin of these cells.

Fixatives↗
PubMed1979

A human thymocyte antigen defined by a hybrid myeloma monoclonal antibody.

Spleen cells from a BALB/c mouse that had been immunized with human thymocytes were fused with the myeloma line P3-NS 1/1 Ag 4.1. One of the resulting hybrid clones (NA 1/34) secreted an antibody that was highly specific for human thymocytes. Eighty-five % of thymocytes expressed the antigen designated HTA1. There were an estimated 15 x 10(4) molecules of HTA 1 per cell, and it is therefore a major surface molecule. The expression of this antigen on thymocytes appears to be reciprocal to HLA, as recognized by another monoclonal antibody W6/32. Immunoprecipitated material from [125I]-labeled thymocyte membranes was analyzed by polyacrylamide gel electrophoresis in sodium dodecyl sulfate which disclosed a single component of 45,000 molecular weight.

Animals↗