Biomedical subjects

D Y Mason

Publications and source records attributed to D Y Mason.

At least 235 records · Page 13Linked to original sources

PubMed1985

Immunohistologic demonstration of abnormal colonic crypt cell kinetics in ulcerative colitis.

A monoclonal antibody, Ki-67, that reacts with cells in the proliferative phases (G1, G2, S, and M) of the cell cycle was used in an immunohistochemical labeling reaction to examine the colonic crypt epithelium in active ulcerative colitis, inactive ulcerative colitis, and normal mucosa. The proportions of labeled cells in the lower two thirds (proliferative zone) and in the upper quarter of the crypt were determined. The proportions of Ki-67-positive crypt epithelial cells in both the proliferative zone and the upper crypt were higher in biopsy specimens from patients with active ulcerative colitis than from patients with normal mucosa or with inactive ulcerative colitis. In inactive ulcerative colitis the proportion of Ki-67-positive epithelial cells in the proliferative zone of the crypt was higher than in normal mucosa. These results are similar to those obtained in studies using tritiated thymidine to determine the proportion of cells in the DNA-synthesizing thymidine to determine the proportion of cells in the DNA-synthesizing phase of the cell cycle and suggest that immuno-histochemical staining with Ki-67 may be a practical method for measuring the proliferative activity of epithelial cells in patients with ulcerative colitis and other disorders of the gastrointestinal tract.

Antibodies, Monoclonal↗

PubMed1985

The value of immunocytochemical methods in the differential diagnosis of anaplastic thyroid tumours.

The practical usefulness of a panel of monoclonal antibodies recognising epithelial and lymphoid antigens has been evaluated on a series of 10 routinely processed thyroid tumours of uncertain origin. All 6 small cell tumours were shown to be of lymphoid origin whereas of the 4 large cell tumours two were lymphomas and two carcinomas. Two of the tumours, one large cell and one small cell, were undiagnosable due to technical reasons (crush artefact or small size of biopsy) and emphasized the value of immunohistology in this context. Clinical follow-up of all 10 cases indicated that these distinctions are of both prognostic and therapeutic value. It is concluded that immunocytochemistry using a carefully selected panel of monoclonal antibodies is a valuable and convenient means of making an objective distinction between anaplastic thyroid tumours of epithelial or lymphoid origin.

Aged↗

PubMed1985

Production of monoclonal antibodies against human epithelial membrane antigen for use in diagnostic immunocytochemistry.

Two monoclonal murine antibodies have been raised against a delipidated extract of human cream. These antibodies were detected by immunohistological screening of hybridoma culture supernatants on sections of human breast tissue. One of those antibodies (E29) was subsequently screened against a range of normal and neoplastic human tissues and shown to react with a wide variety of human epithelia and with mesothelial cells. Antibody E29 was unreactive with other cell types, with the exception of occasional plasma cells. Antibody E29 is suitable for use on paraffin embedded tissue and represents a valuable reagent for the identification of tumours of epithelial origin.

Animals↗

PubMed1985

A new monoclonal antibody to epithelial membrane antigen (EMA)-E29. A comparison of its immunocytochemical reactivity with polyclonal anti-EMA antibodies and with another monoclonal antibody, HMFG-2.

Two polyclonal rabbit antibodies to epithelial membrane antigen (EMA), two mouse monoclonal antibodies (E29 and HMFG-2), and a "cocktail" of these two monoclonals have been compared using an indirect immunoperoxidase technique. Sections from 25 tissues (17 malignant and 8 benign), were examined. The distribution of staining with each of these reagents was similar, but the polyclonal antibodies produced stronger staining in colorectal carcinomas and lactating breast, whereas staining with the monoclonal antibodies was stronger in non-neoplastic pleural mesothelium and in pulmonary alveolar cells. When the two monoclonals were mixed there was no increase in staining intensity. E29 gave a "cleaner" result than HMFG-2, with better discrimination between cells and stroma, and is highly suitable for routine diagnostic histopathology.

Antibodies↗

PubMed1985

Lymphomatoid papulosis. Characterization of skin infiltrates by monoclonal antibodies.

Cryostat sections from fully developed papular lesions of lymphomatoid papulosis (histologic subtype A or B) have been examined by immunoenzymatic staining with 24 monoclonal antibodies against lymphoid cells and their subsets. The lesions demonstrated essentially identical cellular compositions and consisted of T-lymphocytes with a peripheral phenotype (Lyt3+, anti-Leu-4+, OKT6-), macrophages (HLA-DR+, EB11+, OKM1+), and Langerhans cells (HLA-DR+, OKT6+). T-helper/inducer cells (anti-Leu-3+) usually dominated over T-suppressor/cytotoxic cells (anti-Leu-2+). In all cases, proportions of the infiltrating T-cells expressed markers associated with activation (HLA-DR, the OKT1O antigen, interleukin-2 receptor) or proliferation (transferrin receptor, the Ki-67 antigen) of lymphoid cells. Furthermore, the infiltrates contained clusters and/or sheets of large cells reactive with antibodies (Ki-1, Ki-24, Ki-27), which recognize Hodgkin's and Reed-Sternberg cells. These data indicate an origin of the cellular infiltrate from transformed or activated lymphoid cells and suggest an interrelationship of lymphomatoid papulosis to Hodgkin's disease.

Adult↗

PubMed1985

Phenotypic characterization of lymphocyte subsets in mycosis fungoides. Comparison with large plaque parapsoriasis and benign chronic dermatoses.

Altogether, 209 skin biopsies from 103 patients with mycosis fungoides (MF), large plaque parapsoriasis (LPP), and benign chronic dermatoses (BCD) have been examined immunohistologically with the use of a panel of 21 monoclonal antibodies against lymphoid cells and their subsets. All the infiltrates contained a mixture of T-lymphocytes, Langerhans cells, and other types of HLA-DR-positive dermal macrophages. The neoplastic T-cells in MF lesions expressed proliferation-(transferrin receptor) and activation-(the OKT10 antigen) associated markers more frequently than the T-cells in LPP and BCD. In other respects, the neoplastic T-cells in plaque lesions of MF resembled those seen in LPP and BCD; and most of these cases demonstrated a clear predominance of T-cells of helper/inducer type. The neoplastic T-cells in tumor lesions of MF were much more heterogeneous in phenotype. Only eight of these cases could be classified as T-helper neoplasms. In the remaining ten tumor cases, the neoplastic cells expressed either suppressor/cytotoxic or aberrant T-cell phenotypes. There were no phenotypic differences between the "classical" tumor stages and MF d'emblee cases. The data indicate that the early lesions of MF show an immunohistologic reaction pattern common to many immune responses of the skin and that the neoplastic cells in the advanced stages are more heterogeneous in phenotype than previously recognized.

Adult↗

PubMed1985

Detection of metastatic tumour cells in routine bone marrow smears by immuno-alkaline phosphatase labelling with monoclonal antibodies.

The present study describes 11 cases (10 carcinomas, one rhabdomyosarcoma) in which immuno-alkaline phosphatase labelling with monoclonal antibodies was used to demonstrate metastatic cells in routine smears of aspirated bone marrow. Carcinoma cells were detected using antibodies against epithelial cytokeratins, milk fat globule membrane antigen and carcinoembryonic antigen, and rhabdomyosarcoma cells with monoclonal anti-desmin. In four of the carcinoma cases it had not been possible to identify malignant cells in routinely stained marrow smears, whilst the case of disseminated rhabdomyosarcoma had initially been diagnosed (and treated) as a case of acute lymphoblastic leukaemia. The anti-cytokeratin antibody was found to be the most valuable of the anti-epithelial reagents used, since it labelled malignant cells in all of the 10 cases of carcinoma and gave the strongest reactions. These results suggest that immunocytochemical labelling should be used in cases of suspected carcinoma whenever conventional examination of marrow smears yields negative results, and furthermore (as illustrated by the case of rhabdomyosarcoma) that the technique is of value for identifying the true nature of poorly differentiated neoplasms in bone marrow.

Aged↗

PubMed1985

Human lung tumours: a correlation of antigenic profile with histological type.

Fifty-four human lung tumours have been immunostained with a large panel of monoclonal antibodies including reagents against cytokeratins, prekeratins, epithelial membrane antigen (EMA), carcinoembryonic antigen (CEA) and neural antigens. These results have been compared with the histological types of tumour using the current WHO classification scheme. The most striking finding of this study was the considerable overlap of antigenic profile between different histological types of tumour. This suggests that there may be a greater underlying similarity between different histological categories of lung tumour than has hitherto been assumed. Secondly it was evident that immunostaining highlighted areas of different morphology within many tumours emphasizing the heterogeneous differentiation patterns seen in lung cancers. The present study supports the viewpoint that lung tumours arise from a common stem cell and that these neoplasms represent a single tumour with a tendency to differentiate along one or more pathways.

Antibodies, Monoclonal↗

PubMed1985

The characterization of two monoclonal anti-keratin antibodies and their use in the study of epithelial disorders.

The present paper describes the production and characterization of two monoclonal antibodies, K20 and K92. Immunohistological staining showed these two antibodies to be specific for keratinizing epithelium. However, whereas K20 stained all layers of the epidermis K92 reacted with only the suprabasal epidermal layers. Immunoblotting studies with preparations of keratins from both the non-cornified (i.e. the basal, spinous and granular layers) and cornified (stratum corneum) layers of epidermis showed that K20 recognized the 46, 48, 50, 55, 56, 56.5, 59, 61, 62, 64, 65, 66 and 67 kd bands, of which the 50 and 46 kd bands appeared to be masked in tissue sections. In contrast, antibody K92 was more restricted in its activity, recognizing only the 55 and 56 kd bands strongly. These antibodies were used in the study of various epithelial disorders and revealed alterations in the epithelial intermediate filament expression in both benign and malignant disease processes.

Animals↗

PubMed1985

An immunocytochemical study of malignant melanoma and its differential diagnosis from other malignant tumours.

A series of 41 fresh and 36 routinely processed malignant melanomas were immunostained with a panel of 12 monoclonal antibodies reactive against a range of epithelial, lymphoid, and melanoma associated antigens. The aim of the study was to determine whether this panel of antibodies would be useful in diagnostically difficult cases for differentiating melanomas from other tumours, particularly carcinomas and lymphomas. The results confirmed that most unequivocal malignant melanomas can be identified by positivity for S100 protein and for the antigen recognised by antibody NK1/C3, and by negativity for epithelial and lymphoid antigens. The incidence of melanomas expressing cytokeratin antigens was higher, however, particularly in cryostat sections than has previously been reported. It is therefore suggested that a panel of antibodies with more than one marker in each category should be used for identifying melanomas in clinical practice.

Antibodies, Monoclonal↗

PubMed1985

Immunocytochemical staining of T and B lymphocytes in serous effusions.

Cell smears from serous effusions containing large numbers of lymphoid cells were stained by the alkaline phosphatase-anti-alkaline phosphatase technique with a panel of monoclonal antibodies, including anti-B and anti-T cell antibodies and anti-HLA-DR. Samples from 17 patients with lymphoproliferative disorders--such as chronic lymphocytic leukaemia and non-Hodgkin's lymphoma--and from 19 patients who had no evidence of lymphoid neoplasia--for example, cases of carcinoma, cardiac failure--were investigated. The majority of lymphoid cells in reactive effusions were T cells, which lacked HLA-DR and showed a marked excess of helper/inducer cells (mean helper to suppressor ratio of 3 X 5). In contrast, lymphoid cells in samples from nine cases of B cell neoplasia were positive for B cell antigen and HLA-DR. In a further four B cell neoplasms most lymphoid cells were reactive T cells. Two cases of T cell lymphoid leukaemia could also be characterised by immunocytochemical staining, both being classified as T helper cell neoplasms. Labelling was performed on routinely prepared, air dried cell smears, which could be stored in the unfixed state for long periods before staining. The technique may therefore be of use in many clinical cytology laboratories for the diagnosis of effusions containing numerous lymphoid cells.

Alkaline Phosphatase↗

PubMed1985

Role of immunohistochemistry in diagnosis of nasopharyngeal tumours.

To evaluate the usefulness of immunocytochemistry in the differential diagnosis of nasopharyngeal tumours, 35 undifferentiated nasal carcinomas were examined with a panel of monoclonal antibodies against a wide variety of epithelial and non-epithelial antigens. The results were compared with those obtained from a series of nasopharyngeal tumours comprising three squamous cell carcinomas, six lymphomas, one rhabdomyosarcoma, and one yolk sac tumour. All of the carcinomas were positive with at least one of the antiepithelial markers and negative for the leucocyte common antigen and were clearly distinguishable from the nasopharyngeal lymphomas, which gave the opposite staining pattern. It was concluded that such a panel of monoclonal antibodies would be extremely useful for the differential diagnosis of nasopharyngeal tumours, particularly with small or technically inadequate biopsies.

Antibodies, Monoclonal↗

PubMed1985

Use of freeze-dried paraffin-embedded sections for immunohistologic staining with monoclonal antibodies.

Most diagnostically valuable monoclonal antibodies recognize antigens that do not survive conventional tissue processing. The use of frozen tissue sections for immunohistologic studies overcomes this obstacle but introduces a number of practical problems, e.g., the necessity to store material in the frozen state, poor morphologic preservation, etc. In the present paper we report that antigenic denaturation during conventional tissue processing appears to occur during exposure to aldehyde-containing fixatives and to alcohol but not as a result of heating or exposure to melted paraffin wax. In consequence, we have developed a technique by which tissue is freeze-dried and then embedded directly in paraffin wax. All but one of the 40 monoclonal antibodies investigated stained the freeze-dried paraffin sections with an intensity equal to or greater than that observed on frozen sections. There was less diffusion artifact and less background staining than in cryostat sections, and cellular morphology was better preserved. One of the most important advantages of this new method is that antigens in freeze-dried paraffin-embedded tissue are stable, and tissue blocks may be handled in the same manner as conventional paraffin blocks. An additional finding was that, once the tissue has been freeze-dried, paraffin embedded, and sectioned, the antigens it contains are resistant to fixatives (e.g., formol, formol sublimate, alcohols) which would very rapidly cause their destruction in frozen sections.

Antibodies, Monoclonal↗

PubMed1985

Monoclonal antibody patterns in lymphomatoid papulosis.

Atypical cells resembling Reed-Sternberg cells are a characteristic histologic feature of lymphomatoid papulosis. Thus far no consistent data are available on the nature of these cells, or a possible antigenic relationship between them and Reed-Sternberg cells. Twenty-four biopsy specimens from 14 patients with lymphomatoid papulosis were immunolabeled with antibodies against Ki-1 and other Reed-Sternberg cell-associated antigens. In all cases a proportion of the large, atypical cells expressed the Ki-1 antigen. In contrast, in 20 biopsy specimens of benign inflammatory skin lesions or mycosis fungoides, Ki-1-positive cells were absent or only occasionally present. Furthermore, the large atypical cells of lymphomatoid papulosis also expressed other antigens (for example, T3, T4, HLA-DR, IL-2 receptors) that have previously been demonstrated on Reed-Sternberg cells. Our findings, together with the observation that the Ki-1 antigen can be induced on peripheral blood lymphocytes after prolonged phytohemagglutinin stimulation, suggest that the Ki-1-positive cells in lymphomatoid papulosis are activated T cells closely related to the Reed-Sternberg cells of Hodgkin's disease.

Antibodies, Monoclonal↗

PubMed1985

The expression of the Hodgkin's disease associated antigen Ki-1 in reactive and neoplastic lymphoid tissue: evidence that Reed-Sternberg cells and histiocytic malignancies are derived from activated lymphoid cells.

Ki-1 is a monoclonal antibody (raised against a Hodgkin's disease-derived cell line) that, in biopsy tissue affected by Hodgkin's disease, reacts selectively with Reed-Sternberg cells. The expression of Ki-1 antigen has been analyzed by immunocytochemical techniques in a wide range of human tissue and cell samples, including fetal tissue, malignant lymphomas (290 cases), and mitogen- and virus-transformed peripheral blood lymphocytes. The antigen was detectable on a variable proportion of cells in all cases of lymphomatoid papulosis and angio-immunoblastic lymphadenopathy and in 28% of the cases of peripheral T cell lymphomas (including lympho-epithelioid lymphomas). It was also expressed (more strongly) on tumor cells in 45 cases of diffuse large-cell lymphoma, most of which had originally been diagnosed as malignant histiocytosis or anaplastic carcinoma, because of their bizarre morphology. However, all of these cases lacked macrophage and epithelial antigens. Thirty-five cases expressed T cell-related antigens (associated in nine cases with the coexpression of B cell-related antigens), seven bore B cell-related antigens alone, and three were devoid of T and B cell markers. DNA hybridization with a JH specific probe showed a germline configuration in 11 cases of T cell phenotype, in two cases lacking T and B cell antigens, and in one case of mixed T/B phenotype, while rearrangement was found in two cases of clear B cell type and in one mixed T/B case. Expression of the Ki-1 antigen could be induced, together with interleukin 2 (IL 2) receptor, on normal lymphoid cells of both T and B cell type by exposure to phytohemagglutinin, human T leukemia viruses, Epstein-Barr virus, or Staphylococcus aureus. The results obtained indicate that Ki-1 antigen is an inducible lymphoid-associated molecule that identifies a group of hitherto poorly characterized normal and neoplastic large lymphoid cells. Tumors comprised solely of these cells show both morphological and immunological similarities to the neoplastic cells in Hodgkin's disease. This suggests that both disorders represent the neoplastic proliferation of activated lymphoid cells of either T cell or, less commonly, B cell origin. Disorders in which only a minority of cells express Ki-1 antigen (lymphomatoid papulosis, angio-immunoblastic lymphadenopathy, and certain T cell lymphomas) probably represent lesions in which only some of the abnormal cells have transformed into an "activation state." In direct support of this view is the finding that the Ki-1 expression in these lesions is accompanied by the expression of HLA-DR and IL 2 receptors.

Adolescent↗

PubMed1985

The human gut contains a novel population of B lymphocytes which resemble marginal zone cells.

B cells in normal human Peyer's patches and in primary B cell lymphomas of the stomach have been characterized in terms of their cellular morphology and their reactivity with a panel of monoclonal antibodies. A population of B cells is present in normal and malignant gut-associated lymphoid tissue which is composed of neither mantle zone cells nor germinal centre cells. In Peyer's patches these cells surround the follicles merging with the mantle zone and extending both into the dome region, infiltrating between the epithelial cells and also towards the serosa. They are intermediate in size with irregular nuclear outlines and they resemble the centrocytes in the follicle centre. They are quiescent, expressing C3b- and C3d-receptors and surface IgM but not surface IgD. These centrocytes-like cells which are not seen in the peripheral lymph nodes are identical to the B cells in the marginal zone of the spleen according to all of the criteria employed in this study.

B-Lymphocytes↗

PubMed1985

Human B cell development. I. Phenotypic differences of B lymphocytes in the bone marrow and peripheral lymphoid tissue.

The phenotype of B lineage cells (TdT+, pre-B, IgM+, IgD-, and IgM+,IgD+) in infant and adult human bone marrow was compared with that of B cells seen in peripheral tissues such as tonsil and blood. The range of B cell-associated antibodies used included four reagents with greater than 90% reactivity on peripheral B cells: RFB4 and To15 (both p135, corresponding to CD22), RFB6 (p140 corresponding to CD21), and Y29/55, a unique B cell-specific antibody. In addition, AL-1, an antibody with virtually no reactivity against peripheral B cells was also used. The BM cell subpopulations were heterogeneous in respect of antibody reactivity. The TdT+, pre-B and IgM+, IgD- cells were AL-1+ but did not express membrane antigens recognized by the antibodies To15, RFB4 (CD22), and RFB6 (CD21). TdT+, pre-B cells, and 50% of IgM+, IgD- BM B cells were also unreactive with antibody Y29/55, the other 50% being Y29/55+. In contrast, the IgM+,IgD+ BM B cells, like peripheral B cells, were positive with antibodies To15, RFB4, RFB6, and Y29/55, but reacted only in small numbers with AL-1. The orderly differentiation-linked display of these antigens was also suggested by the findings that normal TdT+, pre-B, and IgM+,IgD- cells expressed the To15 and RFB4 (CD22) antigens in their cytoplasm (in the Golgi region). This observation was confirmed in malignant common acute lymphoblastic and pre-B blast cells, as well as in the corresponding permanent cell lines KM3 and NALM-6. In these lines the membrane expression of To15 and RFB4 could be induced by phorbol ester during a 48 to 72 hr culture period.

Adolescent↗

PubMed1984

Human lymphoid cells express epithelial membrane antigen. Implications for diagnosis of human neoplasms.

Epithelial membrane antigen (EMA) is generally assumed to be expressed only on epithelial cells. However, EMA was also found on reactive and neoplastic plasma cells, on some non-Hodgkin's lymphomas (particularly cases of T-cell lymphoma and "malignant histiocytosis"), and on Reed-Sternberg cells in cases of lymphocyte-predominant Hodgkin's disease. EMA was also induced on normal blood lymphocytes by exposure to human T-lymphotropic virus type II or phytohaemagglutinin. The specificity of these aberrant reactions was confirmed by the use of three different monoclonal anti-EMA antibodies (E29, HMFG2, and LICR.LON/M8), and by showing that EMA in lymphoid tissue is similar in molecular weight to EMA in human milk. These results indicate that additional anti-epithelial antibodies (eg, anti-cytokeratins) should be used in conjunction with anti-EMA for tumour diagnosis.

Antibodies, Monoclonal↗