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A Heryet

Publications and source records attributed to A Heryet.

At least 19 recordsLinked to original sources
PubMed1994

Expression of a homologously recombined erythopoietin-SV40 T antigen fusion gene in mouse liver: evidence for erythropoietin production by Ito cells.

We have obtained transgenic mice in which an erythropoietin-SV40 virus T antigen fusion gene is homologously recombined into the native Epo locus. This gene is expressed in a tissue-specific manner closely resembling that of the native Epo gene. Immunohistochemical detection of SV40 T antigen has been used to characterize the hepatic cell populations expressing the transgene. In mice stimulated by anaemia or hypobaric hypoxia, SV40 T antigen was demonstrated in two liver cell populations: a subset of hepatocytes and a nonparenchymal cell type. Immunohistochemical and ultrastructural characterization of these cells by light and electron microscopy showed the nonparenchymal cell type to be the Ito cells, which lie in a persinusoidal position within the space of Disse. We therefore conclude that Ito cells are the nonhepatocytic source of liver Epo production. These cells show many similarities to the Epo-producing fibroblastoid interstitial cells of the kidney.

Anemia↗
PubMed1993

Identification of the renal erythropoietin-producing cells using transgenic mice.

Regulation of erythropoietin production by the kidneys is central to the control of erythropoiesis. Uncertainty about the identity of the renal cells involved has been a major obstacle to understanding this mechanism. We have used sequence from the mouse erythropoietin locus to direct expression of a marker gene, SV40 T antigen, to these cells in transgenic mice. The transgenic constructs contained an oligonucleotide marker (Epo-M) or SV40 sequence (Epo-TAg) in the 5' untranslated region of the mouse erythropoietin gene, flanked on each side by 9 and 7.5 kb of DNA from the mouse erythropoietin locus. Anemia-inducible expression of Epo-M and Epo-TAg was observed in the kidney. In one of thirteen lines, homologous integration of Epo-TAg into the mouse erythropoietin locus occurred. In transgenic mice bearing Epo-TAg at homologous and heterologous insertion sites, renal expression was restricted to a population of cells in the interstitium of the cortex and outer medulla. Immunohistochemical characterization by light and electron microscopy shows that these are the fibroblast-like type I interstitial cells.

Animals↗
PubMed1993

Inappropriate expression of blood group antigens on biliary and colonic epithelia in primary sclerosing cholangitis.

The distribution of carbohydrate antigens of the ABO, Lewis, and Kell systems was examined in biliary and colonic epithelial of 11 patients with primary sclerosing cholangitis (PSC) using a panel of 11 monoclonal antibodies. Controls consisted of 27 liver biopsy specimens (11 normal, six alcoholic liver disease, five extrahepatic obstruction, and five primary biliary cirrhosis) and 24 colonic biopsy specimens (six normal, four Crohn's disease, and 14 ulcerative colitis). There was inappropriate staining with anti-A (four of six, 66%) and anti-B (nine of 11, 81%) in biliary epithelium of PSC patients compared with normal and disease controls. Expression of Lewis antigens was increased in patients with cholestatic liver disease. Ninety one per cent of PSC patients showed a similar pattern of inappropriate staining by anti-A and anti-B antibodies in colonic epithelium compared with 33% of normal and 42% of inflammatory bowel disease controls. There is inappropriate expression of A and B carbohydrate antigens in biliary and colonic epithelium in PSC. Whether these oncofetal antigens are implicated in the pathogenesis of this condition is discussed.

Adult↗
PubMed1993

Intramural platelet deposition in cerebral vasculopathy of systemic lupus erythematosus.

AIMS: To test the hypothesis that fragments of platelet thrombi and vascular endothelium are incorporated into the walls of small cerebral vessels in systemic lupus erythematosus (SLE). METHODS: Six varied necropsy cases of central nervous system (CNS) SLE and 15 controls were studied. The controls were selected to represent a wide range of diseases in which the cerebral circulation is compromised. Tissue sections were stained by standard histochemical and immunocytochemical methods, the latter using antibodies to platelet membrane glycoprotein IIIa (CD61), and vascular endothelium (CD31). RESULTS: In four of six cases of CNS SLE characterised by small vessel hyalinization and thickening, fragments of platelet membrane were found in the walls of small cortical and meningeal vessels. Similar findings were not evident in two other SLE cases that were characterised by relatively short clinical histories and an acute vasculitis. One control case of severe polyarteritis nodosa showed platelet fragment deposition in arteries larger than the vessels so affected in SLE. CONCLUSIONS: Previous studies have suggested that neuropsychiatric symptoms in SLE may be related to repeated episodes of vasculitis in small cerebral vessels that are triggered by antiphospholipid antibodies. Concurrent thrombus formation might facilitate the incorporation of platelet fragments into small vessel walls. This process contributes to the thickening and irregularity of small vessels, a major feature of longstanding cases of CNS SLE.

Adult↗
PubMed1993

p53 expression in colorectal adenomas.

To assess the expression of p53 in premalignant lesions, we examined by immunohistochemistry benign colorectal adenomas (n = 72, measuring more than 6 mm and less than 95 mm in diameter) from patients without (group I, n = 23) or with (group II, n = 49) concurrent sporadic colorectal carcinomas. Using a panel of three monoclonal antibodies (PAb 240, PAb 421, PAb 1801) and two polyclonal antibodies (CM1, C19) immunohistological staining was demonstrated in 26% of the cases (19 of 72 adenomas, 7 of 23 from group I and 12 of 49 from group II). In the majority of the cases, p53 positive foci in the adenomas occurred in the most dysplastic areas, although focal positivity was detected in glands that were histologically normal. Expression of p53 protein was also detected in 21 of 30 (70%) colorectal carcinomas of group II. In two cases focal positive staining was observed in the polyps but not in the concurrent carcinomas. Non-neoplastic colonic mucosa and stromal lymphoid cells were negative in all cases examined. Over-expression of p53 in neoplastic tissues detected by immunocytochemistry is generally believed to correlate with the presence of mutation in the gene. This may not be an absolute rule, because in some hemopoietic malignancies, there is evidence that p53 protein may be detectable in the absence of an underlying mutation. These findings therefore represent the highest incidence in colorectal adenomas of abnormalities in the p53 protein expression, probably largely due to underlying mutations. This study also suggests that immunocytochemical demonstration of p53 protein may be a suitable method for the routine detection of subpopulations of cells which, by clonal expansion, could acquire a growth advantage within an adenoma during the neoplastic process.

Adenoma↗
PubMed1992

Immunocytochemical staining of serous effusions with the monoclonal antibody Ber-EP4.

Cytospin preparations were made from 102 serous effusions for immunocytochemical staining using a panel of monoclonal antibodies including a new monoclonal antibody Ber-EP4. On cytological examination, 32 fluids were reported to contain tumour cells consistent with metastatic adenocarcinoma; 66 contained benign cells only and three were reported to contain cells suspicious of malignancy. One effusion contained tumour cells consistent with malignant mesothelioma. Positive staining of the tumour cells with Ber-EP4 was observed in the 32 effusions (100%) which contained adenocarcinoma cells. No staining of the mesothelial cells in these 32 specimens was observed. Carcinoembryonic antigen, epithelial membrane antigen Ca2 and CD15 staining of tumour cells was noted in 53%, 50%, 50% and 9% of these cases, respectively. None of the mesothelial cells in the benign effusions stained with Ber-EP4. Nor did the malignant mesothelial cells in the only case of malignant mesothelioma. These findings suggest that Ber-EP4 is a valuable addition to antibodies available for the differential diagnosis of mesothelial cells and adenocarcinoma cells in serous effusions.

Antibodies, Monoclonal↗
PubMed1991

The L1 antigen and squamous metaplasia in the bladder.

The L1 antigen was investigated as a marker of squamous differentiation in urothelium using a monoclonal antibody Mac387, and the results were compared with the expression of high molecular weight cytokeratins. L1 antigen was consistently demonstrated in all instances of partial and complete squamous metaplasia and in squamous carcinomas. In contrast, pure transitional cell carcinomas (except one with minor focal staining), adenocarcinomas and normal and hyperplastic urothelium did not label. In a few squamous carcinomas in situ, the pattern of labelling obtained with Mac387 was different from that seen in invasive squamous carcinomas and metaplasias. Compared with high molecular weight cytokeratins, the expression of L1 was more intense in areas of squamous differentiation. L1 expression, as identified by antibody Mac387, may therefore serve as a useful marker of squamous differentiation in urothelial lesions.

Antibodies, Monoclonal↗
PubMed1991

Immunophenotyping of Nigerian cases of non-Hodgkin's lymphomas on paraffin sections.

One hundred cases of routinely fixed and processed non-Hodgkin's lymphoma from Nigeria were immunostained with a small panel of monoclonal antibodies against B-, T- and macrophage antigens. The aims of the study were to assess the suitability of stored material from a country like Nigeria for immunohistochemical examination and the ability of the antibody panel to evaluate the distribution of B- and T-cell neoplasms. Eighty-seven of the 100 cases gave interpretable immunostaining, with 75 being B-cell and 12 T-cell neoplasms. Eighty-seven of the 100 cases gave interpretable immunostaining, with 75 being B-cell and 12 T-cell neoplasms. There were no tumours of macrophage lineage. Four cases gave satisfactory staining of reactive lymphoid cells but no reactivity with malignant cells and thus were not phenotyped. The remaining nine cases gave no staining of neoplastic or reactive cells, suggesting that they were unsuitable for immunohistochemical study, presumably because of inappropriate fixation and handling. We concluded that a panel of three monoclonal antibodies is suitable for routine immunostaining of conventionally fixed and processed blocks in Third World countries and will give diagnostically useful information in approximately 95% of cases.

Antibodies, Monoclonal↗
PubMed1990

Megakaryocytes in myelodysplasia: an immunohistochemical study on bone marrow trephines.

Megakaryocytes in 63 bone marrow trephine biopsies were examined for their staining characteristics, location and size distribution using the monoclonal antibody Y2/51 directed against platelet glycoprotein IIIa (CD61). Megakaryocytes in normal bone marrow were evenly distributed and demonstrated homogeneous staining with Y2/51. In addition, there was little variation in their size or shape. In contrast, myelodysplastic and myeloproliferative bone marrow trephines showed considerable dysmegakaryopoiesis demonstrated by heterogeneity of staining, an altered architectural distribution with a predominantly paratrabecular location and considerable variation in size and shape. Furthermore, in myelodysplasia 25% of the CD61 positive cells were micromegakaryocytes as opposed to less than 10% in normal or reactive marrows. Such dysmegakaryopoiesis is believed to be a clinically important feature of myelodysplasia, although until now it has only been possible to assess it subjectively. The availability of the monoclonal antibody Y2/51 provides a rapid and reproducible means of studying megakaryocyte size, shape and distribution in routine trephine specimens and may help to overcome some of the diagnostic problems currently associated with myelodysplasia and other intrinsic bone marrow neoplasias.

Antibodies, Monoclonal↗
PubMed1990

Angioleiomyomas: an immunohistological study.

In a series of nine angioleiomyomas, nerves were identified immunohistologically within the capsule and interstitium only in those that were painful. We believe that it is stretching of capsular nerves that underlies most of the patients symptoms.

Adult↗
PubMed1990

Combined non-isotopic in situ hybridisation and immunohistochemistry on routine paraffin wax embedded tissue: identification of cell type infected by human parvovirus and demonstration of cytomegalovirus DNA and antigen in renal infection.

A method for combined immunohistochemistry using alkaline phosphatase antialkaline phosphatase (APAAP) and in situ hybridisation using biotinylated probes was developed. The method requires no change to either technique and no additional procedures between them. The procedure was able to show the cell types involved in parvovirus infection of the fetus. The efficiency of immunohistochemistry and in situ hybridisation for the detection of cytomegalovirus in kidney were also compared: occasional cells contained cytomegalovirus DNA but not antigen. The method is rapid, straightforward, and has wide applications in the study of viral infections, genes, and gene products in tissue sections because it permits the combined demonstration of antigen and nucleic acid on the same section in routine clinical material.

Antigens, Viral↗
PubMed1989

The utility of Ki67 immunostaining, nuclear organizer region counting, and morphology in the assessment of follicular lymphomas.

Three methods, the enumeration of large non-cleaved cells (LNCC), the enumeration of nucleolar organizer regions (AgNORs), and the estimation of the percentage of Ki67-positive cells, have been compared on a series of 36 follicular lymphomas for their utility in subclassification. All three methods produced similar subdivisions to those obtained using the histological classification of the Working Formulation for clinical usage. Twenty cases have been followed clinically to assess any relationship between these parameters and short-term (less than 4 years) survival. Each technique showed a trend towards identifying patients with a poor short-term prognosis with no one method being superior to any other. Unless larger series with longer follow-up suggest otherwise, there is no indication to use either the AgNOR or Ki67 methods which offer no advantage over the simple and inexpensive Working Formulation or Berard's LNCC counting.

Antibodies, Monoclonal↗
PubMed1989

Peripheral blood and portal tract lymphocyte populations in primary sclerosing cholangitis.

The relative distribution of lymphocyte subpopulations in the blood and liver of patients with primary sclerosing cholangitis (PSC) and related diseases has been studied using immunoenzyme techniques. The peripheral blood CD4/CD8 T lymphocyte ratio was significantly higher in active ulcerative colitis (UC) and in PSC with inactive UC than in inactive UC alone. In contrast, no relationship with disease activity was seen in Crohn's disease. The portal tract t lymphocyte count per high power field (mean +/- S.D.) was higher in pre-cirrhotic PSC (173 +/- 105) and primary biliary cirrhosis (PBC: 210 +/- 110) than in histologically normal liver (42 +/- 27). However, the overall portal tract CD4/CD8 ratio was similar in PSC (1.49), PBC (1.89) and normal controls (1.63). The results are consistent with immunological involvement in the pathogenesis of PSC, but argue against the hypothesis that changes in the peripheral blood T cell subsets are due to sequestration at the site of tissue inflammation.

Adolescent↗
PubMed1989

The origin and nature of stromal osteoclast-like multinucleated giant cells in breast carcinoma: implications for tumour osteolysis and macrophage biology.

The origin and nature of osteoclast-like multinucleated giant cells (OMGCs), in extraskeletal neoplasms, is uncertain. The ultrastructure, antigenic phenotype and function of OMGCsm in a breast carcinoma were studied in order to clarify the relationship between OMGCs, osteoclasts and other cells of the mononuclear phagocyte system (MPS). OMGCs resorbed cortical bone in a manner similar to osteoclasts. However, unlike osteoclasts, OMGCs did not possess a ruffled border or clear zone, and expressed HLA-DR and Fc receptors and CD14, CD16, CD18 and CD11 (p150,95) antigens. In addition, OMGCs failed to respond morphologically to calcitonin and were directly stimulated by parathyroid hormone (PTH) to increase bone resorption. These findings suggest that OMGCs are a specific type of macrophage polykaryon distinct from both osteoclasts and other types of inflammatory polykaryon. Occasional smaller (20-25 microns) macrophage-like cells were also associated with resorption pits. Bone resorption by OMGCs isolated from the breast indicates that a cell of the MPS can be transplanted to a new tissue location and perform a highly specialised function appropriate to an MPS cell of that tissue (i.e. the osteoclast). PTH stimulation of bone resorption by OMGCs suggests that PTH or a PTH-like protein, may be involved in the bone resorption and consequent hypercalcaemia associated with metastatic breast cancer.

Antigens, Differentiation↗
PubMed1989

The prognostic significance of immunophenotype in high-grade non-Hodgkin's lymphoma.

The prognostic value of immunophenotyping lymphomas was assessed by studying 51 cases of high-grade non-Hodgkin's lymphoma for which long term clinical follow-up (14-28 years) was available. Using antibodies which identify T- and B-cell-related antigens in formalin-fixed, paraffin-embedded material, 43 were shown to be of B-cell and eight of T-cell phenotype. In terms of survival, cases of high-grade T-cell lymphoma fared significantly worse (P less than 0.05) than cases of high-grade B-cell subtype. These findings support the belief that T-cell lymphomas have a more aggressive clinical course than their B-cell counterparts.

Antibodies, Monoclonal↗
PubMed1989

Use of betapropiolactone to disinfect fresh tissue without impairing antigenicity: method applicable to human immunodeficiency virus (HIV) positive tissue.

A method for inactivating viruses in tissues is reported that does not impair the antigenicity of the Coxsackie virus or of some common tissue antigens, a common problem with standard tissue fixation methods. Tissues can be placed briefly in Betapropiolactone before cryostat sectioning without any adverse effect on preservation or antigen expression. It is suggested that use of Betapropiolactone is applicable to tissues harbouring or exposed to the human immunodeficiency virus (HIV). As betapropiolactone has been reported to be carcinogenic in rodents any potential danger can be avoided by basic simple precautions.

Antigens, Viral↗
PubMed1988

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↗