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T Finn

Publications and source records attributed to T Finn.

36 records · Page 2Linked to original sources
PubMed1989

Identification of Epstein-Barr virus-infected cells in tonsils of acute infectious mononucleosis by in situ hybridization.

In situ hybridization with 35S-labeled Epstein-Barr virus (EBV) probes was applied to paraffin sections of tonsils from seven patients with clinical, serologic, and morphologic evidence of acute infectious mononucleosis. EBV genomes were demonstrated in activated lymphoid B blasts in the interfollicular and perifollicular zones in all these cases. However, in no case could EBV be identified in epithelial cells. These results are at variance with the current concept which attributes a central role to the tonsillar epithelium in primary EBV infection.

Acute Disease↗
PubMed1989

In situ hybridization using biotinylated probes. An evaluation of different detection systems.

In situ hybridization with biotin-labelled DNA probes is a powerful tool for the detection of viral sequences in infected tissues. However, sensitivity is low when compared to radiolabelled probes. In order to evaluate the impact on staining results of the detection system applied, we have tested various reagents. In our hands the sequential application of streptavidin and biotinylated alkaline phosphatase or development with a monoclonal anti-biotin antibody and the APAAP method gave consistently the best results. Furthermore, nitro blue tetrazolium/bromochloroindolyphosphate seems to be most suitable as a substrate for the alkaline phosphatase in this case. Use of other reagents, especially of a streptavidin-biotinylated alkaline phosphatase complex, resulted in a significantly lower staining intensity.

Alkaline Phosphatase↗
PubMed1989

Detection of viral genomes in the liver by in situ hybridization using 35S-, bromodeoxyuridine-, and biotin-labeled probes.

Methods employing 35S-, biotin-, and bromodeoxyuridine (BrdUrd)-labeled DNA probes were compared for the detection of hepatitis B virus (HBV) and cytomegalovirus (CMV) in the liver. The results demonstrate that: 1) HBV can be detected reliably only by the use of radiolabeled probes, whereas methods employing nonradioactive probes obviously are not sensitive enough for this virus. The use of 35S-labeled probes shortens the exposure times considerably in comparison to tritiated probes. 2) Biotin-labeled probes are of limited value for in situ hybridization on liver tissues because the presence of endogenous avidin-binding activity often leads to false positive results. 3) Brd-Urd-labeled probes are a useful alternative to biotinylated probes for the detection of CMV. In comparison with biotinylated probes, BrdUrd-labeled probes produce a specific signal of similar staining intensity in the absence of background staining in the liver.

Biotin↗
PubMed1988

Myeloid antigen expression on common acute lymphatic leukaemia blasts after culture.

Blast cells from seven out of ten patients with common acute lymphoblastic leukaemia (cALL) developed the myeloid antigen MY7 (CD13) after culture, and one of these coexpressed the myeloid antigen MY9 (CD33). CD13 expression appeared to be independent of maturation since it could be induced more readily in cultures which did not contain the differentiation promoter 12-O-tetradecanoyl-phorbol 13 acetate (TPA). CD13 expression in culture was not seen on one null ALL, or 6 B-CLL investigated or on normal tonsillar B cells or PBMC under similar conditions. CD13 expression on cALL blasts probably represents evidence of abnormal gene expression in the leukaemic cells. However the absence of CD13 expression on the earlier B null ALL or the later B-CLL suggests we cannot exclude the possibility that CD13 expression is a feature of normal precursor B cells.

Adult↗
PubMed1988

Detection of cytomegalovirus by in situ hybridisation and immunohistochemistry using new monoclonal antibody CCH2: a comparison of methods.

In situ hybridisation, immunohistochemistry, and morphological analysis for the detection of cytomegalovirus (CMV) were compared in routinely processed tissue sections from a patient with acquired immune deficiency syndrome (AIDS) and widespread CMV infection. Both in situ hybridisation and immunohistochemistry with the monoclonal antibody CCH2 labelled all "owl's eye" cells intensely and, in addition, nuclei of some morphologically normal cells. Quantitative evaluation of the results showed that in situ hybridisation and immunohistochemistry with CCH2 were considerably more sensitive than purely morphological analysis, particularly in tissues with only a few cells infected by CMV. It is further shown that immunohistochemistry with CCH2 detected a higher figure of CMV infected cells than in situ hybridisation. In conclusion, both in situ hybridisation and immunohistochemistry are rapid, sensitive, and specific methods for CMV detection. For routine purposes, however, immunohistochemistry seems to be more suitable.

Acquired Immunodeficiency Syndrome↗
PubMed1988

Detection of viral DNA by in situ hybridization using bromodeoxyuridine-labeled DNA probes.

Detection of viral DNA in infected tissues is demonstrated by in situ nucleic acid hybridization employing bromodeoxyuridine (BrdUrd)-labeled probes. BrdUrd is used alternatively to biotinylated nucleotides in the preparation of DNA probes and, after hybridization, developed with a monoclonal anti-BrdUrd antibody and the alkaline phosphatase-anti-alkaline phosphatase technique. The sensitivity using both BrdUrd- and biotin-labeled probes is similar. Furthermore, the simultaneous detection of viral coinfections will be possible by means of this technique in conjunction with biotin-labeled DNA probes.

Bromodeoxyuridine↗
PubMed1987

The simultaneous presentation of peripheral T-cell lymphoma and hairy cell leukemia.

A patient who presented simultaneously with B hairy cell leukemia (HCL) and peripheral T-cell lymphoma (PTL) is described. The diagnoses of the two neoplasms were made by standard morphologic and cytochemical study and confirmed immunologically. There was no evidence of overlap in markers to suggest that they arose from a single clone of malignant cells. It is suggested that the simultaneous occurrence of the two neoplasms in the same patient reflects an underlying predisposition to the development of neoplasia in HCL.

Antibodies, Monoclonal↗
PubMed1987

A useful low temperature method for post-embedding electron immunocytochemistry in routine histopathology.

Using a low temperature resin, we have developed a reliable technique for post-embedding electron immunocytochemistry which is rapid enough to be used in a routine histopathology laboratory. Glutaraldehyde fixed human tissues were dehydrated and embedded at -25 degrees C in a new acrylic resin called LR-Gold. Using the immunogold technique, ultra-thin sections of the tissues were labelled with monoclonal antibodies to cytokeratin, human milk fat globule and HLA-D region antigen; and with polyclonal antisera to lysozyme, kappa and lambda light chains and immunoglobulin M. The resin was easy to section and the preservation of fine structure was excellent. Immunolabelling procedures gave clean and consistent results, and electron micrographs of examples of this are included. It was felt that the preservation of ultrastructure and antigenicity compared well with the results of other workers using low temperature resins such as Lowicryl K4M, but LR-Gold was superior to Lowicryl K4M because sectioning was considerably easier and the sections were more stable in the electron beam.

Acrylic Resins↗
PubMed1986

A comparative study of the gut-associated lymphoid tissue of primates and rodents.

Previous studies have suggested that the gut-associated lymphoid tissue (GALT) of man is distinct from that of laboratory animals, but it is not clear whether this is due to environmental or true species difference. We have made a comparative study of rats and baboons because, like rats, baboons are herbivorous and relatively unhygienic but they are phylogenetically much more closely related to man. The Peyer's patches of rats, baboons and man are morphologically very similar in all three species but phenotypically those of man and baboons are different to those of rats. Cells with irregular nuclei ("centrocyte-like" cells) surround the mantle zone in all three species. While these cells express surface IgD and IgM in rats, in man and baboons they express surface IgM or IgA. A population of immunoblasts which express cytoplasmic IgA are present in association with the high endothelial venules of rat Peyer's patches. These cells are not present to the same extent in man or baboons. This suggests that the events between the antigenic stimulation of Peyer's patches and the ultimate seeding of the lamina propria with IgA secreting plasma cells may be different in rodents and primates.

Animals↗
PubMed1986

Primary B-cell gastric lymphoma.

A detailed clinicopathologic and immunocytochemical study was performed in 12 cases of primary gastric lymphoma in which fresh tissue was available for study. The patients ranged in age from 18 to 76 years; persistent epigastric symptoms had led to endoscopy (often on multiple occasions) and biopsy in each case. The endoscopic appearances rarely suggested malignancy. The histologic appearances of the gastrectomy specimens covered a spectrum, from changes normally considered characteristic of "pseudolymphoma" to those of florid malignant lymphoma, with evidence of extragastric spread in four cases. Formation of follicular centers characterized each case, and diffuse interfollicular infiltrates of centrocyte-like cells were also present. Plasma cells were also consistently present. Immunocytochemical studies showed the same light chain restriction of follicular center cells and centrocyte-like cells in all cases and of plasma cells in five cases. Follicular center cells and centrocyte-like cells were otherwise phenotypically distinct. This study yielded criteria for the objective diagnosis of gastric B-cell lymphoma in biopsy and resection specimens; the results suggest that the term pseudolymphoma should no longer be used.

Adolescent↗
PubMed1986

Monocytic differentiation in acute myeloid leukaemia: a cause of Fc binding of monoclonal antibodies.

Cells from 17 patients with acute myeloid leukaemia (AML) were investigated using the following IgG2a monoclonal antibodies cALL, B1 and Leu 1. Cells from six patients showed binding of cALL, five showed B1 and three showed Leu 1 positivity. Binding of the monoclonal antibodies was shown to be due to Fc binding as it was blocked by prior incubation with aggregated human IgG. Measures such as prior incubation with AB serum or incubation at 37 degrees C were insufficient to block Fc binding in all cases. Fc binding correlated with evidence of monocytic differentiation. Our findings suggest that unless Fc binding is outruled false positive results may be obtained in the investigation of lineage infidelity in AML particularly in monocytic leukaemias.

Antibodies, Monoclonal↗
PubMed1986

Expression of HLA-DR antigens on epithelium associated with lymphoid tissue in the human gastrointestinal tract.

Mucosa from human stomach, terminal ileum, appendix, and colon was studied for epithelial HLA-DR expression using an immunoperoxidase technique with a monoclonal antibody that detects HLA-DR antigens in paraffin embedded tissues. Expression of HLA-DR by epithelial cells was studied with particular reference to the effect of adjacent lymphoid tissue or surrounding chronic inflammation. In the stomach, epithelial HLA-DR appeared to be induced by chronic inflammation. Where lymphoid nodules were present only that epithelium directly adjacent to the lymphoid tissue expressed HLA-DR. Expression was independent of cell type. Epithelium adjacent to normal lymphoid tissue in the terminal ileum, appendix, and colon also expressed HLA-DR, the relationship between expression and proximity to lymphoid tissue being remarkably precise. Expression of HLA-DR by gastrointestinal epithelium appears to be an effect of adjacent lymphocytes, whether part of an inflammatory response or normal tissue. This must be taken into account when assessing HLA-DR expression by gastrointestinal epithelium.

Appendix↗
PubMed1986

Human Peyer's patches: an immunohistochemical study.

We have used immunoperoxidase techniques to characterise the Peyer's patches in human terminal ileum. The mantle zones of the B cell follicles in human Peyer's patches were surrounded by B cells which did not express surface IgD but which mostly expressed surface immunoglobulin of the IgM and/or IgA1 isotype. Few cells expressing surface IgG or IgA2 were detected. Cells with cytoplasmic immunoglobulin of all isotypes except IgD were present in the dome regions of the Peyer's patches as well as in the lamina propria. There was little evidence of traffic of immunoglobulin synthesising cells across the high endothelial venules. T cells were seen to surround the lymphoid follicles. They were most concentrated on the serosal aspect around the high endothelial venules. Cells with macrophage-like morphology were present in both the lamina propria and the dome region of the follicles; those in the lamina propria containing lysozyme and those in the dome region S100 protein. The results are discussed in relation to the generation and dissemination of antibody producing cells in human gut.

B-Lymphocytes↗
PubMed1986

The development of gut associated lymphoid tissue in the terminal ileum of fetal human intestine.

Lymphoid tissue in formalin fixed and snap frozen human fetal ileum has been studied using immunohistochemistry. At 11 weeks gestation clusters of cells expressing CD4 (leu-3a positive) are present in fetal ileum but these do not express CD3 (UCHT1 negative) and are probably macrophages. Aggregates of lymphoid tissue are apparent from 14 weeks gestation which contain T cells of helper/inducer and suppressor/cytotoxic phenotype. Both B and T cells are present at 16 weeks but with no cellular zonation. By 19 weeks, distinct follicles of B cells are present surrounded by T cells of helper/inducer and suppressor/cytotoxic phenotype. Follicular dendritic cells are also present within the B cell areas. The B cells at this age express surface IgM and IgD, C3b- and C3d-receptors. They also express the antigen CD5 which has been shown by others to be present on some fetal B cells but which is almost exclusively associated with T cells in the adult. HLA-D region antigens are present on apparently all of the cells within the fetal lymphoid follicles. The antigen on activated B cells, CD23 (recognized by MHM6), was present on some cells scattered within the B cell follicle. This is indicative of antigen independent B cell proliferation.

B-Lymphocytes↗
PubMed1985

Gut associated lymphoid tissue: a morphological and immunocytochemical study of the human appendix.

Gut associated lymphoid tissue in 15 normal appendices has been characterised in tissue sections using both morphological criteria and immunocytochemical techniques. A panel of monoclonal and polyclonal antibodies was used including antibodies to B-cells, T-cells, macrophages, HLA DR and immunoglobulins. The lymphoid tissue in the appendix was shown to bear a strong resemblance to that in lymph nodes with the exception of the region where the appendix follicles associate with the dome epithelium, which has no lymph node equivalent. This zone of cells between the lymphoid follicles and the dome epithelium termed the 'mixed cell zone' has been shown to contain an abundance of HLA DR-bearing cells, some of which have irregular nuclear morphology and resemble follicle centre cells. These cells were seen to extend into the epithelium of the dome but not the crypts. Using a monoclonal anti-B-cell antibody a population of B-cells was detected in the equivalent areas of mixed cell zone and epithelium and quantitative studies showed that these intraepithelial B-cells comprised approximately 4-5% of the cells in the epithelium. The mixed cell zone was also seen to contain T-cells, S-100 protein-containing macrophages and occasional lysozyme-containing macrophages. Plasma cells were rarely seen in this area.

Antibodies, Monoclonal↗
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↗