1,721,086 research outputs found
The analysis of lymphoid subpopulations in normal and malignant tissues by immunofluorescence techniques
No full textTissue sections of frozen biopsy specimens obtained from normal and hyperplastic human lymphoid tissues as well as 40 cases of non-Hodgkin's lymphomas were analysed in immunofluorescence tests (using red TRITC and green FITC double-labeling). A panel of antisera including well-characterized conventional reagents to immunoglobulin classes, T-lymphoid and Ia-like antigens and monoclonal antibodies, including the OKT range made by Ortho Laboratories, was used. The findings show that the immunological methods can give a very accurate analysis of the normal and malignant lymphoid cells and can provide complementary information to conventional histology. Furthermore, the monoclonal antibodies to well defined lymphocyte subsets can provide data which suggests (although does not prove) functional relationships between different types of cells in normal and malignant lymph nodes. Thus, the technology described fills the gap between conventional histology and cellular immunology
Immunohistological analysis of bone marrow involvement in lymphoproliferative disorders. The use of cryostat sections from trephine biopsies
No full textCryostat sections from frozen samples of human bone marrow trephine biopsies were used for immunohistochemical analysis. Immunoperoxidase and immunofluorescence techniques as well as enzyme histochemistry were applied to these sections in order to characterize bone marrow infiltrates in lymphoproliferative diseases. Various conventional antisera and monoclonal antibodies and several enzymes were able to identify different normal and malignant cell populations. This technology provides a new tool to be used in combination with classical morphology for studying bone marrow involvement during lymphoid malignancies
Immuno-histochemical characterisation of cells involved in dermatopathic lymphadenopathy
No full textNormal and pathological lymph nodes exhibiting the features of dermatopathic lymphadenopathy were analysed by immunochemical methods. Various antisera to human Ia-like antigens, to immunoglobulin, to T cells and myelo-monocytic cells were used. The paracortical enlargement typical of the condition was due to interdigitating cells containing Ia-like antigens on their membrane, and to adjacent T lymphocytes. The intensity of staining with anti-Ia-like serum on the interdigitating cells was comparable to the very strong staining of the fewer reticular cells present in the T dependent areas of normal nodes and normal spleen, and to the staining of Langerhans cells in the skin and appear to be higher than that seen on B lymphoid cells. These cells do not exhibit immunoglobulin and do not react with antisera made against circulating granulocytic and monocytic cells. Since sinus histiocytes of normal nodes and histiocytes in massive lymphadenopathy showed very weak staining with anti-Ia-like serum, strong Ia expression seems to be restricted to a subclass of mesenchymal cells which might be involved in the regulation of T cell function
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Immunohistochemical analysis of thymoma. Evidence for medullary origin of epithelial cells
No full textThe histologic organization of lymphoid and nonlymphoid (epithelial and interdigitating) cells in a thymoma has been compared to that of the normal thymus. Enzyme and immunohistochemical methods were applied, using both conventional antisera (to cytokeratin) and monoclonal antibodies (to epithelial cells, HLA-DR and lymphoid subsets). Throughout the tumor, the epithelial cells shared phenotypical similarities with the epithelial cells of thymic medulla (RFD-4 positive, cytokeratin strongly positive, and HLA-DR essentially negative). On the other hand, the lymphoid cells were heterogeneous in phenotype and distribution, and "mimicked" the distribution seen in the normal infant thymus. Immature thymocytes of cortical type (TdT+, OKT6+, OKT3-) were predominant in the areas with moderate lymphocytic infiltration (ML). Mature T-lymphocytes (TdT-, OKT6-, OKT3+) were found mainly in areas with scanty lymphocytes (SL) together with an additional population of HLA-DR positive interdigitating and HLA-DR+, OKT6+ Langerhans'-type cells. These findings indicate that in thymoma tissue, the lymphoid elements of cortical type are apparently surrounded by an inappropriate (medullary) epithelium
Routine immunofluorescent and histochemical analysis of bone marrow involvement of lymphoma/leukaemia: the use of cryostat sections
No full textEnzyme histochemical and immunohistological (immuno-fluorescence and -peroxidase) techniques have been routinely used for investigating over 70 normal and pathological bone marrow samples. This recently standardized diagnostic procedure is very quick and can be performed in a few hours. In 6 cases the clinical diagnosis of leukaemia/lymphoma has become apparent only after the immunohistological analysis of the bone marrow. In 6 other cases the information about the staging of B cell malignancies was superior in the frozen biopsies to the paraffin embedded preparations. Amongst many other features the monoclonality of B CLL/lymphomas, the special features of B CLL infiltrates (RFA-1+, Leu-1+, HLA-DR+, SmIg+), follicular lymphoma deposits (containing follicular dendritic cells) and non-T, non-B acute lymphoblastic leukaemic blasts (terminal transferase+, HLA-DR+) as well as the sometimes conspicuous presence of infiltrating normal T cells could be clearly and reproducibly demonstrated
Microenvironments in the normal thymus and the thymus in myasthenia gravis
No full textThe disposition of epithelial cells and extracellular matrix, in the thymus of 8 cases of myasthenia gravis (MG) and in controls (over a wide age range) was studied. In the controls, the subcapsular epithelium was strongly Leu-7-positive in the fetus, negative in childhood, and positive again in adults. Another antibody, RFD4, also labeled the subcapsular epithelium in childhood and adults, but not fetal samples. The samples from MG cases showed the same staining pattern as adult control samples. The medullary epithelium was also RFD4+, and at all ages. The most striking changes in the advanced cases of MG were the unusual arrangement and hypertrophic appearance of medullary epithelial cell areas, separated by laminin-positive basement membranes from the alternating multiple bands of peripheral lymph-node-like areas. The latter had regions resembling the paracortex of lymph nodes as well as germinal centers (GCs). The T-cell zones contained heavy deposits of fibronectin. These T-cell zones were unique to the thymus in MG and were absent in the two normal thymic samples with isolated GCs. In MG the laminin-containing basement membrane, which separated the medullary epithelial and peripheral lymph-node-like areas, was fenestrated at circumscribed points closest to the GCs, thus apparently permitting communication among the medullary epithelium, the T-cell zones, the GCs and the associated antigen-presenting cells. Large numbers of interdigitating cells and some lymphocytes of cortical thymocyte phenotype were also found at these special sites, where opportunities for autosensitization may persist in MG
Combined immunological and histochemical analysis of skin and lymph node lesions in histiocytosis X
No full textThe immunological phenotype of the cells involved in skin and lymph node lesions from two cases of histiocytosis X (H-X) were analysed by immunofluorescence techniques using combinations of heterologous and monoclonal antisera to Ia-like antigen and human cortical thymocyte (HTA-1) determinant. These cells were also characterised by a new technique using simultaneous immunofluorescence and enzyme histochemistry for acid phosphatase (ACPase). The major cell type in the lesions was found to express the same Ia+, HTA-1+ phenotype as normal epidermal Langerhans' cells (LC) and was unreactive for ACPase. Additional cell types included Ia-, HTA-1- multinucleate giant cells and residual lymphoid populations. These findings endorse previous concepts that H-X is a proliferation of abnormal LC and emphasise the heterogeneous nature of the cells involved in the disease
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