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Biomedical subjects

A Heryet

Publications and source records attributed to A Heryet.

At least 37 records · Page 2Linked to original sources

The immunohistology of synovial lining cells in normal and inflamed synovium.

The immunohistology of synovial lining cells (SLCs) in normal and inflamed hyperplastic synovium was investigated using monoclonal antibodies directed against leucocyte common antigen (LCA) HLA-DR and other macrophage components. We found that some SLCs in normal synovium express LCA, HLA-DR, and monocyte/macrophage-associated antigens. The number of SLCs expressing these antigens is increased in hyperplastic osteoarthritic (OA) and rheumatoid (RA) synovium. Some SLCs which did not react for LCA or other macrophage markers but were positive for HLA-DR were also noted in normal synovium and some segments of hyperplastic OA synovium. SLCs which are positive for LCA, HLA-DR, and macrophage markers contribute to the intimal hyperplasia in RA where they account for the majority of SLCs in the synovial intima. In OA synovium, the distribution of SLCs showing this pattern of reactivity was less uniform with numerous SLCs which were positive for HLA-DR but negative for LCA and other macrophage markers also present in the synovial intima. These findings indicate that there are some SLCs of bone marrow origin in normal and hyperplastic synovium. They also suggest that recruitment of SLCs of marrow origin is important in the production of intimal hyperplasia in both RA and OA and that there is also a significant local proliferation of non-marrow derived SLCs in OA.

Adult↗

An investigation into the nature of giant cells in cardiac and skeletal muscle.

In an immunohistochemical study of six cases of giant cell myocarditis, the typical giant cells have been shown to express up to four different macrophage-associated antigens, but not desmin, the intermediate filament protein characteristic of muscle cells. These results support the view that the giant cells have a macrophage rather than a myogenic origin. In contrast, the giant cells found in regenerating skeletal muscle have the immunophenotype of muscle cells and not of macrophages supporting their muscle origin.

Adult↗

Granular cell tumours revisited. An immunohistological and ultrastructural study.

Twenty-five granular cell tumours were stained with a panel of antibodies to histiocytic, muscle, neural, neural crest, epithelial and endothelial markers. Electron microscopy was also performed in six cases. Twenty-four of the cases were similar morphologically and immunocytochemically. One case with features of an endothelial origin is described. The present study strongly supports the viewpoint that granular cell tumours are a distinct entity rather than being the common appearance of a group of lesions of differing histogenesis. Origin from a neural crest-derived peripheral nerve-related cell is favoured.

Humans↗

The immunohistological detection of platelets, megakaryocytes and thrombi in routinely processed specimens.

The production and characterization of a new monoclonal antibody, Y2/51, against platelet glycoprotein IIIa is described. A useful feature of this antibody is its ability to recognize platelets and megakaryocytes in formalin-fixed routinely processed material. It could also be used to reveal platelets both in thrombi in large vessels and in microthrombi too small to be readily apparent on conventional microscopic examination. For this purpose it was helpful to use the antibody in conjunction with a new monoclonal reagent (Ret40f) against red cell sialoglycoprotein beta which detects red cells and their precursors in routinely processed tissue. The use of these antibodies should be valuable for the detection of thrombi in a variety of situations such as renal transplant rejection, coronary artery disease and vasculitis.

Animals↗

Expression of HLA-DR antigens on bile duct epithelium in primary sclerosing cholangitis.

The expression of HLA class I (HLA-A, B, C) and class II (HLA-DR) antigens on the biliary epithelium of 10 patients (nine men) with primary sclerosing cholangitis (PSC) was investigated using an immunoperoxidase technique on cryostat sections. Five patients were staged as grade II and five grade III on hepatic histology. None were cirrhotic. as grade II and five grade III on hepatic histology. None were cirrhotic. Controls were nine patients with primary biliary cirrhosis (PBC), five with extra hepatic biliary obstruction, 15 with other forms of chronic liver disease and six with normal livers. Bile ducts from the normal subjects and patients with chronic liver disease did not express HLA-DR antigens. In contrast, all 10 of the PSC biopsies showed varying degrees of HLA-DR staining of the biliary epithelium. Expression of DR antigens was also found on the bile ducts of all five patients with extra hepatic biliary obstruction and in six of nine patients with PBC. Expression of HLA class I antigens was seen on the biliary epithelium of all the biopsies examined. Increased numbers of helper and suppressor T-cells were seen in the portal tracts of all the PSC patients. This study has confirmed that aberrant expression of HLA-DR may occur on the biliary epithelium of some, but not all, patients with PBC. In addition, the study has shown that aberrant expression of HLA-DR always occurs in PCS at an early stage of histological liver damage. While this may be important in the pathogenesis of PSC, the aberrant expression in extra hepatic biliary obstruction suggests that it may be a secondary phenomenon.

Adult↗

Localization of platelet antigens and fibrinogen on osteoclasts.

The antigenic phenotype of the human osteoclast, which is known to be derived from a circulating mononuclear precursor cell of haemopoietic origin, is controversial. Recent studies have shown that macrophage as well as megakaryocyte/platelet antigens are expressed by osteoclasts. In this study, we have sought to define, by immunohistochemistry, the nature and possible function of platelet antigens expressed by human osteoclasts in foetal and adult bone specimens. Monoclonal antibodies to platelet glycoprotein IIIa (gpIIIa) and CD9 antibodies stained osteoclasts in all bone specimens examined. Fibrinogen was also localized to the osteoclast membrane in foetal bone imprints. In addition, we found that CD9 and gpIIIa antibodies reacted weakly with monocytes in buffy coat smears. Antibodies to factor 8 and glycoproteins Ib and IIb/IIIa did not react with osteoclasts. These results show that osteoclasts, monocytes, macrophages, megakaryocytes and platelets possess common antigens and that fibrinogen is present on the surface of osteoclasts. By analogy with platelets, CD9 and gpIIIa may play a role in fibrinogen binding by osteoclasts. Possible mechanisms by which platelet antigens and fibrinogen binding could affect osteoclast function are proposed.

Antibodies, Monoclonal↗

Is it necessary to embed bone marrow biopsies in plastic for haematological diagnosis?

With the increase in the use of bone marrow trephines for diagnosis have come numerous reports that traditional methods of preparation (by decalcification and embedding in paraffin wax) should be replaced by plastic embedding to avoid decalcification. It has been argued that only by this means can the high quality preparations needed for accurate haematopathological diagnosis be achieved. The present study challenges this viewpoint and argues that with a little extra care and attention conventional paraffin embedding techniques can give equally high quality preparations. Sections prepared in this way meet the diagnostic needs of the haematologist, without requiring a separate technique to be established in the pathology laboratory solely for bone marrow trephines.

Biopsy↗

Human lung tumours: does intermediate filament co-expression correlate with other morphological or immunocytochemical features?

Co-expression of intermediate filaments is being increasingly reported for many human tumours including carcinoma of the lung. However, it is unclear whether such findings are unusual or restricted to a group of highly atypical tumours. In the present study the pattern of co-expression of intermediate filaments in 94 human lung tumours has been correlated with light and electron microscopical features which are thought to be atypical for particular tumour types. These same aberrant patterns of intermediate filament co-expression have also been compared with the proliferative rate of these tumours as determined by labelling with the monoclonal antibody Ki67. The results of this study have shown that the aberrant expression of intermediate filaments is not a feature unique to a group of highly unusual tumours but is found throughout the spectrum of lung cancer. The implications of these findings for the use of anti-intermediate filament antibodies in pulmonary pathology are discussed with suggestions for future directions which might be taken in this field.

Adenocarcinoma↗

Systemic amyloidosis of beta 2-microglobulin type: a complication of long-term haemodialysis.

A patient receiving long-term haemodialysis developed systemic amyloidosis, which was shown immunohistochemically to be of beta 2-microglobulin type, a previously unrecognised form of systemic amyloidosis. Histologically, the amyloid deposits were closely associated with foci of acute and granulomatous inflammation and vasculitis, although it was not clear if the amyloid deposits directly caused the inflammatory process, or if amyloid was deposited preferentially in areas of inflammation of uncertain aetiology.

Adult↗

Expression of intermediate filament proteins in normal and diseased thyroid glands.

A total of 67 samples from normal and pathological thyroid glands were stained (as formalin fixed paraffin sections) with a panel of monoclonal antibodies directed against intermediate filament proteins. The study confirmed previous reports of cytokeratin and vimentin coexpression in primary thyroid carcinomas, but coexpression was also detected in normal thyroid and in a range of benign conditions including follicular adenomas, Hashimoto's thyroiditis, and diffuse hyperplasia (thyrotoxicosis). Prekeratin expression was found (using antibodies recognising higher molecular weight cytokeratins) predominantly in areas of squamous change, independent of the underlying thyroid pathology. This study does not therefore support previous findings that prekeratin expression provides a reliable means of distinguishing follicular pattern papillary carcinoma from follicular carcinoma with its poorer prognosis or that it helps distinguish benign from malignant papillary lesions. No evidence of desmin or neurofilament expression was seen, and in particular, neurofilaments could not be detected in any of the cases of medullary carcinoma studied.

Antibodies, Monoclonal↗

Effect of decalcification agents on immunoreactivity of cellular antigens.

The effects of several strong acids, weak acids, a proprietary decalcifier, and edetic acid on the immunohistochemical staining of cryostat and fixed paraffin embedded sections of tissue from a variety of normal and pathological calcified and uncalcified specimens were studied. Even decalcification in strong acids (HCl, HN03, 5% trichloracetic acid, HCl-edetic acid did not diminish the reactivity of many useful antigens (including leucocyte common antigen, intermediate filaments, S100 protein and epithelial membrane antigen). Weaker acids (formic acid, acetic acid) and edetic acid decalcified more slowly and generally showed greater preservation of antigenic reactivity with better morphology and staining quality. Trichloracetic acid was also useful as a quick one step fixation and decalcifying agent for both cryostat and routinely processed sections. Knowledge of the preservation of antigenic reactivity in decalcified tissue will be useful in the diagnosis of tumours of uncertain histogenesis and origin which affect calcified tissues.

Acids↗

Immunocytochemical analysis of HLA class II (DR) antigens in liver disease in man.

The in situ distribution of the major histocompatibility (HLA) class II (DR) antigens was studied in 113 liver biopsy specimens and five livers obtained at necropsy, using monoclonal antibody CR3/43. In 20 normal livers HLA-DR antigens were not detected in bile duct epithelium, hepatocytes, or portal vein endothelium. Normal arteriolar, sinusoidal and central venous endothelium often expressed HLA-DR. Kupffer cells always expressed these antigens. HLA-DR positive spindle cells were identified in the connective tissue of portal tracts, large hepatic veins, and liver capsule: most shared antigens common to all leucocytes and reacted with the histiocytic maker EBM11. Bile duct epithelium expresses HLA-DR in primary biliary cirrhosis, large duct obstruction, and drug induced cholestasis, indicating that HLA-DR positive spindle cells are phenotypically similar to histiocytes.

Antibodies, Monoclonal↗

Osteoclasts contain macrophage and megakaryocyte antigens.

The origin and mechanism of formation of the osteoclast remains controversial. Although it is known to be derived from a circulating mononuclear percursor, the identity of this cell is unknown. Using a panel of monoclonal antibodies raised against macrophage and other marrow-derived cells, we determined the immunocytochemical staining of human osteoclasts in both fetal bone metaphyseal imprints and frozen sections. Osteoclasts and marrow mononuclear cells were stained by three broad spectrum antimacrophage antibodies, EBM-11, Y182a and BM2. T310, an antibody which stains macrophages and T helper cells, and C17, an antimegakaryocyte antibody, also stained osteoclasts. EBM-11, Y182a and BM2 also stained megakaryocytes in bone imprints as well as normal bone marrow smears. The presence of macrophage-associated antigens in osteoclasts, megakaryocytes and bone marrow mononuclear cells indicates that they are phenotypically similar to macrophages.

Antibodies, Monoclonal↗

Dendritic reticulum cells in reactive lymph nodes and tonsils: an immunohistological study.

There has recently been much interest in the patterns of follicular dendritic reticulum cells (DRC) in pathological lymph nodes, particularly in relation to the phenomenon of DRC break-up (thought to be pathognomonic of AIDS-related lymphadenopathies) and to progressive transformation of germinal centres (as a possible precursor of lymphocyte predominant Hodgkin's disease). In the present study we have immunostained twenty-nine reactive lymph nodes and five tonsils with monoclonal antibody R4/23 (DAKO-DRC) in order to evaluate the frequency of such changes in lymphoid tissue unaffected by AIDS or Hodgkin's disease. Most of the specimens contained typical secondary follicles with clearly defined germinal centres and mantle zones. There were two variants in lymph nodes showing follicular hyperplasia characterized by (i) progressive transformation of germinal centres and (ii) inclusions of nests of small lymphocytes within germinal centres. In each of these types of follicles the compact evenly-distributed meshwork of DRCs, as previously described, was seen. However there were considerable variations in DRC meshwork in each category (the pattern could not be predicted from the morphology) with examples in all three of the DRC break-up previously considered specific for the AIDS related lymphadenopathy. Since none of the lymph nodes and tonsils studied had any known relationship to either Hodgkin's disease or AIDS it is argued that none of the changes in the DRC meshwork observed are specific for these conditions.

Acquired Immunodeficiency Syndrome↗

Clinical importance of analysing malignant tumours of uncertain origin with immunohistological techniques.

The value of immunohistology in the histopathological diagnosis of malignant tumours was evaluated in a series of 120 consecutive routinely processed biopsy specimens, all of which had been referred by histopathologists because of diagnostic difficulties. The specimens were analysed by means of a panel of monoclonal and polyclonal antibodies reactive with antigens which resist routine tissue processing. The tumours had previously been considered unclassifiable (24 cases) or categorised as probable carcinomas (43 cases) or lymphomas (53 cases). All but 8 of the 120 cases could be classified with the immunohistological technique. Lymphoma was the commonest diagnosis (66%) and accounted for 29 of the 43 cases initially thought most likely to be anaplastic carcinomas. Immunohistological methods can now resolve the majority of difficulties arising over the histological diagnosis of malignant tumours, and these methods should therefore be used on a wide scale by diagnostic histopathology laboratories.

Antibodies, Monoclonal↗

An immunohistological study of giant-cell tumour of bone: evidence for an osteoclast origin of the giant cells.

Using a panel of monoclonal antibodies against a variety of lymphoid and non-lymphoid antigens the immunohistological staining pattern of giant cells from a case of giant-cell tumour of bone has been compared with that of osteoclasts from the developing ends of fetal long bones. Only EBM-11, an antibody reacting with a wide spectrum of macrophages, stained both osteoclasts and giant cells; stromal cells and osteoblasts did not react. This indicates that osteoclasts and giant cells are phenotypically and presumably functionally similar. It is argued that the osteoclasts and the tumour-derived giant cells in bone are derived from a similar mononuclear precursor.

Adult↗

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↗