The 14;18 translocation in European cases of follicular lymphoma: comparison of Southern blotting and the polymerase chain reaction.

The 14;18 chromosomal translocation is widely recognized as a cytogenetic abnormality associated with follicular lymphomas, but estimates of its frequency in this type of lymphoma vary widely from less than 50% to almost 90%. Furthermore, no extensive data have been published on the frequency of t(14;18) in European cases of follicular lymphoma. Lymph nodes from 51 patients with follicular lymphomas obtained from two European centres (Oxford and Copenhagen) were examined for the presence of this translocation.

Expression of the bcl-2 oncogene protein is not specific for the 14;18 chromosomal translocation.

It has been reported previously that the bcl-2 protooncogene protein is detectable in neoplastic cells from cases of human lymphoma in which the 14;18 chromosomal translocation is present, but not in lymphomas that lack this chromosomal rearrangement or in normal lymphoid tissue. In the present study we confirmed, by immunohistologic labeling with polyclonal and monoclonal antibodies, that bcl-2 protein is strongly expressed in many cases of follicular lymphoma and that these neoplastic follicles differ clearly from their nonmalignant counterpart (reactive germinal centres) in which bcl-2 protein is undetectable. However we also found bcl-2 protein in normal T- and B-lymphoid cells and in a variety of lymphoproliferative disorders in which the 14;18 translocation is not present.

The bcl-2 gene and 14;18 translocation in lymphoproliferative disorders.

The 14;18 translocation is generally considered a good marker for follicular lymphomas and it has also been suggested that it is of prognostic significance in this disease. It has also been claimed that the bcl-2 protein can be detected by immunohistology only in lymphoma carrying t(14;18). We have raised antibodies to the bcl-2 protein and shown that expression of the protein is not specific for the translocation and have also demonstrated that there is no correlation between prognosis and the presence of the translocation.

HBV and HIV expression in lymph nodes of HIV positive LAS patients: histology and in situ hybridization.

The presence of hepatitis B virus (HBV) and human immunodeficiency virus (HIV) was investigated using hybridization in 15 lymph nodes and one Kaposi's sarcoma skin lesion obtained from HIV-positive patients. Cryostat tissue sections were hybridized with chemically modified DNA probes for HBV and HIV. HIV genome was mainly observed in the cytoplasm of cells present in 7/15 lymph nodes and in the Kaposi's sarcoma skin lesion, thus indicating the expression of HIV replication.

Expression of HIV in lymph node cells of LAS patients. Immunohistology, in situ hybridization, and identification of target cells.

Monoclonal antibodies (MAb) anti-HIV core and envelope proteins and in situ hybridization, using cDNA HIV probe, were employed to determine which lymph node cells in LAS patients express viral antigens and viral nucleic acids. The results have been correlated with the histologic phases of LAS and with the germinal center lysis detected using DRC-1 MAb directed against follicular dendritic reticulum cells (FDRC). Viral antigens occasionally were detected on high endothelial cells of paracortical venules and frequently on germinal center FDR accessory cells; this last finding correlates well with the extent of FDRC lysis and of CD4+ and CD8+ lymphocyte infiltration in germinal centers.

B- and T-cell non-Hodgkin's lymphomas with large multilobated cells: morphological, phenotypic and clinical heterogeneity.

Ten cases of non-Hodgkin's lymphomas, mainly composed of large multilobated cells, have been studied. Our results are consistent with the view that they represent a somewhat heterogeneous group of lymphoid tumours displaying different morphological, clinical and immunophenotypic features. In B-cell type the large multilobated cells were histologically characterized by prominent nucleoli and distinctly basophilic cytoplasm whereas in the T-cell type they had indistinct or small nucleoli and ill-defined weakly eosinophilic cytoplasm.

Immunohistochemical heterogeneity of macrophage subpopulations in human lymphoid tissues.

The mononuclear phagocytic system is composed of cells which display a marked immunohistological heterogeneity. In the present study we have investigated the immunohistochemical and enzymatic features of macrophages and accessory cells present in human lymph nodes and spleen and, as control tissues, in thymus, liver, skin and heart. Our investigation has demonstrated that macrophages present in germinal centres display an immunophenotype different from that of macrophages populating T-dependent areas.

In situ hybridization of human immunodeficiency virus (HTLV-III) in cryostat sections of lymph nodes of lymphadenopathy syndrome patients.

The presence of human immunodeficiency virus (HIV, or HTLV-III) genome sequence was investigated by means of in situ hybridization in cryostat sections of lymph nodes from lymphadenopathy syndrome (LAS) patients. The technique employed involved the modification of the DNA probe by chemical insertion of an antigenic sulfone group in cytosine moieties and the visualization of DNA by a double-antibody immunohistochemical reaction. The hybrid formation was revealed in five out of ten cases: in all positive samples, HIV was mainly observed in the cytoplasm of lymph node cells.

Distribution of p24 HTLV3 major core protein in lymph nodes of LAS patients.

Lymph nodes of patients with lymphadenopathy syndrome (LAS) are characterized by two main histological patterns: hyperplastic reactive (H) and regressive (R). In both conditions, the paracortex (PC) is markedly activated with presence of selectively Ia-1+ high endothelial venules. Using a monoclonal antibody for p24, the major core protein of HTLV3, we have immunohistochemically determined the distribution of p24+ cells in lymph nodes from 23 LAS patients' HTLV3-ab serologically positive.

Immunohistochemical demonstration of p24 HTLV III major core protein in different cell types within lymph nodes from patients with lymphadenopathy syndrome (LAS).

The p24 protein is the major core protein of LAV/HTLV III which is the putative agent of the lymphadenopathy syndrome. By the use of an anti-p24 monoclonal antibody we have studied the presence of LAV/HTLV III infected cells in 20 lymph nodes obtained from lymphadenopathy syndrome patients: 14 lymph nodes were characterized by prominent follicular hyperplasia consistent with the early phase of the syndrome and six lymph nodes presented marked regressive changes. Cells positive for p24 were detected in 8/14 lymph nodes with hyperplastic changes and in 1/6 lymph nodes with regressive changes.

Systemic lymphadenopathy (LAS) in intravenous drug abusers. Histology, immunohistochemistry and electron microscopy: pathogenic correlations.

In the present study we have evaluated the histological, immunohistochemical, ultrastructural and cell surface phenotypic features of lymph nodes from 19 intravenous drug abusers and two homosexual men with persistent lymphadenopathy syndrome and from six control patients. Our investigation has demonstrated that the lymphadenopathy of drug abusers is characterized by: (a) specific histological features with evidence of evolution from an initial hyperplastic-reactive to a late regressive-destructive stage; (b) T-cell surface phenotype distribution similar to that in the peripheral blood of homosexuals; (c) peculiar infiltration of the germinal centres by T8+ cells and by S-100+, T6+ interdigitating reticulum-like cells; (d) electron microscopic features indicating the presence of virus bodies in lymph node cells and in the intercellular spaces. These data suggest that the lymphadenopathy of drug abusers and homosexuals are similar pathological conditions with characteristic features which allow histological differentiation of this entity from those found in other viral infections.

Lectin I of Ulex europaeus as a marker for a subset of histiocytic tumours of the lymph node.

We describe four lymph node based tumours in which numerous neoplastic cells and some mitotic figures were characterized by staining affinity for Lectin I of Ulex europaeus (UEA-I). The patients had no vascular or epithelial tumours and presented symptoms suggestive of a systemic lymphoproliferative disease. Histologically, the tumours were composed of large, cohesive, cells which were mainly located in the paracortex.

The Omenn's syndrome: histological, immunohistochemical and ultrastructural evidence for a partial T cell deficiency evolving in an abnormal proliferation of T lymphocytes and S-100 +/T-6 + Langerhans-like cells.

A 7 month old female infant was affected by a rapidly fatal familial disease highly reminiscent of Omenn's syndrome. She presented with widespread eczematous lesions, hepatosplenomegaly, superficial lymphadenopathy, peripheral blood lymphocytosis, eosinophilia and hyper-IgE. An axillary lymph node was involved by a marked proliferation of T-3 +/T-10-- lymphocytes admixed with S-100+/T-6+/Leu-3a+/Ia + reticular cells which lacked typical LC granules; cell suspension study revealed that 90%-96% of the lymph node cells were T-11+/T-3+ lymphocytes characterized by low expression of Leu-3a and T-8 antigens and by high expression of Ia antigens (52%).

[The problem of Parkinsonism associated with the motor neuron disease. Clinical report on 11 sporadic cases (author's transl)].

The clinical data are presented of 11 subjects affected by a sporadic form of Parkinsonism with associated motor neuron disease. Combined lesions of upper and lower neuron were found in 10 of 11 cases, while in the remaining case only lower motor neuron disorder was present. The female/man ratio is 1/11.

[Autofluorescent cells in the sacculus rotundus in the rabbit].

Many autofluorescent cells, rich in yellow pigment are described in the rabbit's sacculus rotundus. This pigment stained positively with Sudan black, PAS and Masson-Hamperl techniques. The cells correspond to those described in rat and in mice lymphatic organs.