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D H Wright

Publications and source records attributed to D H Wright.

At least 73 records · Page 4Linked to original sources
PubMed1994

Orange-red birefringence of gold particles in paraffin wax embedded sections: an aid to the diagnosis of chrysiasis.

Chrysiasis, the systemic deposition of gold pigment in patients on long term chrysotherapy, is identified histologically as small black granules within macrophages. Histological sections from 12 confirmed cases of chrysiasis were examined under crossed polarized light. This revealed a striking orange-red birefringence of the pigment not detected in other histologically similar deposits. This technique provides a valuable adjunct to the histological identification of gold without the need to resort to ultrastructural and analytical procedures.

Antirheumatic Agents↗
PubMed1994

Microwave antigen retrieval in immunocytochemistry: a study of 80 antibodies.

AIMS: To evaluate the effect of microwave irradiation on the staining quality of a range of commonly used primary antibodies in archival, formalin fixed, paraffin wax embedded material, with emphasis on antibodies that have previously worked successfully only on frozen tissue. METHODS: Immunocytochemistry (streptavidin-biotin complex technique) was performed on histological sections of a range of normal and pathological tissues, after varying treatment with microwave irradiation. The staining quality of each antibody was compared with that achieved without prior treatment of the sections or after enzyme predigestion. RESULTS: Microwave irradiation permitted successful immunostaining with 20 antibodies that stained only frozen tissues before. The staining characteristics of 21 antibodies that were already known to stain formalin fixed, paraffin wax embedded material were improved. Another 39 antibodies did not show enhanced staining with microwave irradiation. The method preserves tissue morphology and produces more consistent staining than that achieved by enzyme predigestion with many antibodies. Microwave irradiation may also allow some primary antibodies to be used at higher working dilutions. The citrate buffer used in this study avoids the necessity of exposure to heavy metal salts. CONCLUSIONS: Microwave antigen retrieval represents an important technical advance within immunocytochemistry that will greatly increase the range of antibodies which can be used to study formalin fixed, paraffin wax embedded tissues.

Antibodies, Monoclonal↗
PubMed1993

Epitheliotropism in high-grade lymphomas of mucosa-associated lymphoid tissue.

Low-grade lymphomas of mucosa-associated lymphoid tissue (MALT) characteristically show centrocyte-like cells, plasmacytic differentiation, follicular colonization and lymphoepithelial lesions (epitheliotropism). High-grade lymphomas of MALT are thought to lack these features and can only be identified as MALT lymphomas with confidence if they are admixed with residual low-grade tumours. We studied 23 cases of MALT lymphoma of the thyroid. Six were predominantly low-grade, 12 were predominantly high-grade, and five contained both low- and high-grade areas. All cases were stained for cytokeratin, epithelial membrane antigen and laminin using an immunoperoxidase technique. The low-grade lymphomas all contained lymphoepithelial lesions, generally in the form of clusters of intra-acinar centrocyte-like cells. Eleven of the 12 high-grade MALT lymphomas of the thyroid also showed lymphoepithelial lesions. These appeared in three forms: follicles or clusters of epithelial cells infiltrated by groups of centrocyte-like cells, intra-acinar clusters of blast cells, or irregular invasion of islands of epithelial cells by blast cells. The first pattern presumably represented residual low-grade tumour over-run by high-grade lymphoma. The second two patterns indicated that the factors that result in epitheliotropism in low-grade MALT lymphomas are also present in high-grade tumours. Following this study we identified epitheliotropism in single examples of high-grade MALT lymphomas of the bronchus and small intestine. Previous failure to recognize epitheliotropism in high-grade MALT lymphomas of the gastrointestinal tract may be due to loss of the affected epithelium. The localization and relatively good prognosis of high-grade MALT lymphomas may be related to retention of MALT characteristics including epitheliotropism.

Epithelium↗
PubMed1993

T-cell-rich B-cell lymphoma presenting as liver disease.

We describe a series of eight cases of T-cell-rich B-cell lymphoma diagnosed on liver biopsy and collected over a period of 15 years. Of seven cases that were referred from elsewhere, in only one was the correct diagnosis of B-cell lymphoma suggested. Common errors included misdiagnosis as inflammatory disease on histology, and misinterpretation as T-cell lymphoma on immunohistochemistry. However, the cases had a distinct morphological appearance and immunohistochemical profile. They showed a lymphohistiocytic or granulomatous infiltrate, usually centred on portal tracts and containing abundant small T-cells and scanty B-cell blasts. All patients had an atypical clinical presentation which favoured non-neoplastic liver disease. In seven cases liver involvement represented Stage IV disease and in one case disease was confined to the liver consistent with a primary hepatic lymphoma. Despite combination chemotherapy, the prognosis was poor with no patients surviving beyond 15 months from diagnosis. We believe T-cell-rich B-cell lymphoma to be an under-recognized subset of non-Hodgkin's lymphoma that may mimic primary liver disease.

Aged↗
PubMed1992

Cytogenetic and molecular studies of t(14;18) and t(14;19) in nodal and extranodal B-cell lymphoma.

We have examined 107 cases of B-cell lymphoma for the t(14;18) translocation, characteristically described in follicular lymphoma. B-Cell lymphomas of extranodal origin, and in particular malignancies derived from mucosa-associated lymphoid tissue (MALT), were compared with node-based lymphomas of follicular and diffuse morphology. Cytogenetic techniques were supplemented by molecular analysis using probes which recognize both the major and the minor breakpoint regions of the bcl-2 gene located on chromosome 18 (q21). t(14;18) was detected in 55 per cent of follicular and 27 per cent of diffuse B-cell lymphomas thought to be of follicle centre cell origin. Cytogenetics and molecular analysis proved equally effective in demonstrating the translocation. t(14;18) was not observed in the 36 extranodal lymphomas examined, of which 20 were characterized histologically as lymphomas of MALT, using either technique. In addition, 30 cases demonstrated only a germline band when probed with a bcl-3 probe specific for t(14;19), a translocation observed in chronic lymphocytic leukaemia (CLL). Cytogenetic abnormalities were detected in all cases of extranodal lymphoma, although no consistent abnormality was observed. Numerical abnormalities of chromosomes 3, 6, 16, and 18; structural abnormalities of chromosomes 2, 6, 8, and 9; and small marker chromosomes were frequently seen. This study provides data which suggest that different genetic events are involved in the development of lymphoma of MALT from those giving rise to follicle centre cell lymphomas.

Autoradiography↗
PubMed1992

Epstein-Barr virus latent membrane protein expression by Hodgkin and Reed-Sternberg-like cells in acute infectious mononucleosis.

In the light of reports of latent membrane protein (LMP) expression by Hodgkin and Reed-Sternberg (HRS) cells, paraffin sections of tonsil (two cases), lymph nodes (eight cases; three cervical, one axillary, and four inguinal) and spleen (four cases) from 14 patients with acute infectious mononucleosis (IM) have been examined for the presence of HRS-like cells and immunostained with an antibody to LMP. Sections of the tonsils and one lymph node were also stained with a panel of antibodies which characterize HRS cells of Hodgkin's disease. The tonsils contained abundant HRS-like cells, mainly adjacent to the crypts, which were highlighted by strong LMP expression. The immunophenotype of these cells closely, but not completely, resembled that of HRS cells of Hodgkin's disease. The lymph nodes and spleens showed the typical changes of acute IM but only few LMP-positive HRS-like cells were present in the cervical lymph nodes and hardly any were present in the inguinal nodes and spleen. These findings suggest that tonsillar crypt squamous epithelium may play a role in the formation of LMP-positive HRS-like cells; these cells could be progenitors of Hodgkin's disease HRS cells and, if so, this might explain the restricted sites of presentation of Hodgkin's disease.

Acute Disease↗
PubMed1992

Alpha-1 anti-trypsin and CD30 expression occur in parallel in activated T cells.

We have performed an immunohistochemical study of immunoblastic T cell lymphoma and enteropathy-associated T cell lymphoma for alpha-1 anti-trypsin and CD30. Cytoplasmic staining for alpha 1 anti-trypsin is present in the malignant cells in both types of T cell neoplasm which also express CD30, a marker of lymphoid activation. Peripheral blood T lymphocytes on stimulation with mitogen also show granular cytoplasmic expression of alpha 1 anti-trypsin. Time course studies show that this parallels the expression of CD30. Alpha 1 anti-trypsin expression appears therefore to be associated with activation in T cells. Further studies of sub-fractionated T lymphocytes in vitro suggest that the expression of alpha 1 anti-trypsin on activation is not restricted to an individual lymphocyte subset.

Antigens, CD↗
PubMed1992

The morphological spectrum of monocytoid B-cell lymphoma and its relationship to lymphomas of mucosa-associated lymphoid tissue.

We report 10 cases of monocytoid B-cell lymphoma, five of which had extranodal lymphomas of mucosa-associated lymphoid tissue (MALT) type. In one patient the MALT lymphoma in the salivary gland was microscopic. In another, the small bowel lymphoma, which preceded the monocytoid B-cell lymphoma by 11 years, showed different clonal immunoglobulin gene rearrangements. Attention is drawn to the extreme degree of plasmacytic differentiation and epithelioid cell infiltration that may occur in monocytoid B-cell lymphoma. In addition to the cytological and immunophenotypic likeness of monocytoid B-cells and centrocyte-like cells, monocytoid B-cell and MALT lymphomas share a number of micro-anatomical and behavioural characteristics. These include the sharp separation of the monocytoid B-cells and plasma cells, follicular colonization and progression to high-grade lymphoma. It is suggested that the frequent association of monocytoid B-cell lymphoma with Sjögren's syndrome may be due to the fact that the salivary glands drain to cervical lymph nodes that are part of the systemic, rather than the mucosal, lymphocyte circulation pathway.

Aged↗
PubMed1992

CD43 expression in B cell lymphoma.

AIMS: To determine the expression of CD43 in frozen sections in a range of B cell lymphomas. METHODS: The monoclonal antibody WR14, clustered provisionally in the Fourth Leucocyte Typing Workshop as a CD43 reagent, was investigated by epitope blocking studies on formalin fixed reactive lymph node tissue, using the established CD43 antibody MT1, to validate its use as a CD43 reagent. CD43 expression was studied in 131 immunophenotypically defined B cell lymphomas, including lymphocytic lymphoma (Lc, n = 13), centrocytic lymphoma (Cc, n = 14), and a range of follicle centre cell lymphomas (FCC) including centroblastic/centrocytic follicular (CbCcF, n = 48), centroblastic diffuse (CbD, n = 39), centroblastic/centrocytic diffuse (CbCcD, n = 4), centroblastic follicular and diffuse (Cb FD, n = 3) and centroblastic/centrocytic follicular and diffuse (CbCc FD, n = 1). Nine lymphomas of mucosa associated lymphoid tissue (MALT) were also examined. RESULTS: Epitope blocking studies showed that WR14 is a CD43 reagent that binds to an epitope identical with or close to that recognised by MT1. Eleven of 13 (84%) cases of Lc and 11 of 14 (78%) cases of Cc expressed CD43; 87 of 95 (91%) cases of FCC did not. All eight low grade lymphomas of MALT were negative. One high grade lymphoma, transformed from a low grade MALT lymphoma, was positive for CD43. The expression of CD43 by tumours of B cell lineage was associated with the expression of CD5 (p < 0.001) although either antigen could occasionally be found in the absence of the other. CONCLUSION: CD43 reagents can be used in conjunction with CD5 antibodies for the immunophenotypic discrimination of follicle centre cell lymphomas from non-follicle centre cell lymphomas.

Antibodies, Monoclonal↗
PubMed1992

Alpha-1 antitrypsin gene exon use in stimulated lymphocytes.

AIMS: To investigate the expression of mRNA transcripts containing exon A or B in lymphocyte cultures. METHODS: An in situ hybridisation technique, using synthetic, biotinylated oligonucleotide probes was deployed to allow the demonstration of exon A, exon B, or the normal hepatocyte message containing exon C. RESULTS: Lymphocytes used the same alternative splicing technique as monocytes in the generation of their alpha-1 antitrypsin message. They also provided data on the frequency of exon A and B expression in cells from different subjects. Most circulating granulocytes failed to show the alpha-1 antitrypsin message, suggesting that this protein is synthesised in the marrow and represents a stored protein component in polymorph and circulating nuclear lymphocytes. CONCLUSIONS: In situ hybridisation is a sensitive technique for the detection of individual gene exon use in cell populations. Lymphocytes show the same promoter use as that described for monocytes.

Antisense Elements (Genetics)↗
PubMed1992

Follicular colonization in thyroid lymphoma.

The presence of neoplastic (light chain restricted) B-cell follicles in low-grade B-cell gastrointestinal (GI) lymphoma of mucosa-associated lymphoid tissue (MALT) has been explained on the basis of specific colonization of reactive follicles by centrocyte-like (CCL) cells. Low-grade B-cell thyroid lymphomas have been included in the category of MALT lymphoma, but the frequent presence of a follicular pattern in these tumors has contributed to the view that they are follicle center cell (FCC) tumors. We have reviewed the histology and investigated the phenotype and genotype of nine cases of primary low-grade B-cell lymphoma of the thyroid, all of which were distinguished by a predominantly follicular pattern. All cases also demonstrated features of MALT lymphoma, including CCL cells and lymphoepithelial lesions. The appearances and immunohistology of the follicles were those of follicular colonization as described in GI MALT lymphoma rather than FCC follicular lymphoma. The predominant pattern of follicular colonization was replacement of the follicle center by slightly enlarged CCL cells that showed a strikingly high proliferation rate. No evidence of the t(14;18) translocation was found in any case, using the polymerase chain reaction (PCR) on DNA extracted from fresh (n = 1) or paraffin-embedded (n = 9) tissue. These findings argue against a FCC lineage for primary thyroid lymphomas and support their inclusion in the MALT category.

Base Sequence↗