PubMed Health⌕ Search

Biomedical subjects

A Tabilio

Publications and source records attributed to A Tabilio.

At least 109 records · Page 6Linked to original sources
PubMed1984

Immunological study of in vitro maturation of human megakaryocytes.

Human megakarocyte colonies were grown from the bone marrow in plasma clot or methyl cellulose cultures. Maturation of the megakaryocytic cells was sequentially studied from day 5 to day 16 of culture by fluorescent labelling with a panel of monoclonal and polyclonal antibodies against different platelet glycoproteins (Gp), P1 A1 antigen, factor VIII RAg platelet factor 4 (PF 4), fibrinogen and platelet-derived growth factor (PDGF). Expression of Gp Ib was also studied by immunogold technique at electron microscopy. The first cells identifiable by these antibodies were found at day 5 of culture. They had the size of a lymphocyte. These small megakaryocyte precursors already expressed all the platelet antigens, HLA-DR and transferrin receptors and were devoid of erythroid or myeloid markers. Among the platelet antigens, Gp IIIa was the most sensitive marker for the identification of these precursors. However, double-fluorescent labelling demonstrated that the different platelet markers were coexpressed in a large majority of cells. Interestingly, cytoplasmic markers demonstrated that these small megakaryocyte precursors were themselves heterogenous by morphological criteria. During maturation, expression of Gps, particularly of Gp Ib, increased while the labelling pattern of anti factor VIII RAg and anti PF 4 antibodies switched from diffuse to granular staining. PDGF could also be detected in the megakaryocytes grown in culture.

Antigens↗
PubMed1984

Simultaneous detection of membrane markers with monoclonal antibodies and peroxidatic activities in leukaemia: ultrastructural analysis using a new method of fixation preserving the platelet peroxidase.

Simultaneous detection of specific surface markers by immunogold and intracellular peroxidase activity was determined ultrastructurally in normal and leukaemic progenitors of platelets, erythrocytes and granulocytes. A new method of fixation was employed to preserve platelet peroxidase activity. Monoclonal antibodies to platelet glycoproteins labelled exclusively platelet peroxidase (PPO) positive cells, i.e. platelets, megakaryocytes and promegakaryoblasts (PMKB). In acute megakaryoblastic leukaemia, most PMKB possessed both markers while a few PMKB identified by PPO did not bind monoclonal antibodies. This result suggests that PPO appears earlier in maturation than platelet glycoproteins. Although all glycoproteins (GP) displayed fewer sites in PMKB than platelets, GP Ib was often observed in more mature megakaryocytes. Surface (glycophorin A) and intracytoplasmic markers including ferritin, intra-mitrochondrial iron and diffuse peroxidase activity due to haemoglobin of erythroid progenitors, appeared simultaneously. The number of glycophorin A sites increased with maturation. In leukaemia involving PMKB and proerythroblasts, the surface markers were coincident with the localization of peroxidase activity; glycophorin A was always absent from blasts which exhibited PPO activity localized in endoplasmic reticulum. Platelet glycoproteins were never expressed in any other cell lineage. The myeloid surface antigen was present on normal late neutrophilic promyelocytes after the cessation of myeloperoxidase synthesis. In some cases of M1 and M2 AML (FAB classification), labelling was identical to normal cells while in others the antigen appeared earlier than normal. Our findings show that the surface phenotype of blasts from non-lymphoid leukaemia and the intracellular peroxidase activity of a given cell type can be simultaneously demonstrated and analysed by electron microscopy.

Antibodies, Monoclonal↗
PubMed1984

Expression of SSEA-I antigen (3-fucosyl-N-acetyl-lactosamine) on normal and leukaemic human haemopoietic cells: modulation by neuraminidase treatment.

Several mouse monoclonal antibodies (MoAbs) considered specific for the myeloid lineage recognize the same carbohydrate structure (3-fucosyl-N-acetyl-lactosamine) which is similar to the murine antigen SSEA-I. We have investigated the expression of this antigen with six different well-characterized murine IgM MoAbs on normal, leukaemic, and cultured cells by immunofluorescence and immunoelectron microscope cytochemistry. The cells were studied before and after neuraminidase treatment since epitopes recognized by these MoAbs may be masked by sialic acid. Among the recognizable normal marrow or blood cells, all these MoAbs specifically labelled the granulocytic lineage from the promyelocyte to the polymorph. After neuraminidase treatment, monocytes became labelled. All the other lineages remained unstained. Several cell lines were studied. Six of eight lymphoblastoid cell lines were stained by these MoABs; reactivity was increased by neuraminidase. One Burkitt cell line and two T cell lines were also found to be positive. These antibodies were tested on leukaemic cells. In acute non-lymphocytic leukaemia they usually labelled promyelocytes, more mature granulocytic and monocytic precursors but did not label myeloblasts; after neuraminidase treatment, these myeloblasts became stained. No labelling was observed on leukaemic proerythroblasts and promegakaryoblast before and after neuraminidase treatment except in one case of promegakaryoblastic leukaemia in which the SSEA-I antigen and platelet peroxidase were expressed in the same cell. In addition, six cases of common acute lymphoblastic leukaemia were studied; the blasts became positive after desialylation. Two examples of T cell acute leukaemia were essentially negative. We conclude, therefore, that the reactivity of haemopoietic cells with these MoAbs alone does not represent a criterion sufficient to sustain their myeloid origin since the SSEA-I antigen may be expressed at the surface of all cell lineages in the early phases of haemopoietic differentiation.

Acute Disease↗
PubMed1984

Phenotype study of fresh and cultured hairy cells with the use of immunologic markers and electron microscopy.

The phenotype of fresh and cultured leukemic cells from patients with hairy cell leukemia was studied using a panel of monoclonal antibodies in addition to the detection of peroxidase activity under electron microscopy. In fresh samples, the leukemic cells from 11 patients displayed predominantly a B phenotype, as judged by their reactivity with the B1 monoclonal antibody and surface immunoglobulin expression. Ultrastructural peroxidase activity, characteristic of hairy cells, was observed in all cases studied. When hairy cells were cultured in the presence of phytohemagglutinin and irradiated T cells, their phenotype converted from surface Ig+, B1+, OKT3-, OKT11- to surface Ig-, B1+, OKT3-, OKT11+. In contrast, the peroxidase activity remained unchanged. Some hairy cells were also OKM1+, but no conclusion could be made about the MO2 antigen, a more specific marker of monocytes. The variability of the phenotype in vivo and in vitro indicates that reliable markers are required for identifying hairy cells. When studied together, the staining by B1 monoclonal antibody and the ultrastructural detection of peroxidase, enable the identification of hairy cells with certainty.

Antibodies, Monoclonal↗
PubMed1984

Translocation t(11;14) and trisomy 11q13----qter in multiple myeloma.

A 14q+ marker with extra material derived from chromosome 11 long arm, i.e. segment q13----qter, has been found in cells from a pleural effusion in a patient with highly malignant multiple myeloma. The segment 11q13----qter was trisomic because of the presence of both apparently normal homologous chromosomes 11.

Aged↗
PubMed1983

Erythroid properties of K562 cells. Effect of hemin, butyrate and TPA induction.

Two sublines of the human leukemia cell line K562 including the original cell line and three clones have been investigated for their erythroid features. All of them produce embryonic and fetal hemoglobins, glycophorin A, spectrin and true acetylcholinesterase, but to a varying extent among the cell lines. The Hb and glycophorin contents were correlated in the different K562 cell lines, whereas acetylcholinesterase was independently expressed from these two other erythroid markers. Hb accumulation is enhanced by exposure of the cells to 100 microM hemin without a significant modification of the expression of the other erythroid markers. Butyrate greatly increased the activity of acetylcholinesterase, slightly enhanced the production of hemoglobin, but did not modify the expression of glycophorin and spectrin. 12-O-tetradecanoyl-phorbol-13-acetate (TPA) induced an almost complete disappearance of glycophorin, reduced the synthesis of Hb by K562 cells and also abolished the action of hemin on Hb accumulation. Therefore, all the different K562 cell lines exhibit clear erythroid features including acetylcholinesterase. Butyrate or hemin did not induce terminal differentiation of K562 cells, whereas TPA significantly diminished the erythroid phenotype.

Acetylcholinesterase↗
PubMed1983

The in vivo effect of thymic factor (thymostimulin) administration on circulating immune complexes and serum lysozyme levels in untreated Hodgkin's disease patients.

The in vivo effect of a calf thymus extract, thymostimulin, on the levels of circulating immune complexes (CIC) and serum lysozyme was evaluated in 32 patients with untreated Hodgkin's disease. Using the platelet aggregation test for detecting CICs, 12 patients (37%) had positive titers before thymostimulin treatment; 3 patients (10%) remained positive following therapy. Serum levels of Clq-binding immune complexes were evaluated (greater than 24.5 micrograms/ml) in 8 patients prior to thymostimulin therapy (mean value: 42.3 micrograms/ml); 3 patients continued to have elevated levels after treatment. Serum lysozyme levels for Hodgkin's patients was similar to control values (10.6 vs. 8.3 micrograms/ml); however, the Hodgkin's patients with initially elevated CICs had a lower serum lysozyme level than patients with initially normal CICs (12.9 vs. 7.3, p less than 0.02). Thymostimulin increased serum lysozyme levels in the Hodgkin's patients in whom the CICs were initially elevated (7.3 vs. 10.4 micrograms/ml, p less than 0.05). These data suggest that thymostimulin exerts an effect on the nonspecific immune system of Hodgkin's disease patients.

Animals↗
PubMed1983

Glycoprotein I identification during normal and pathological megakaryocytic maturation.

The expression of glycoprotein I (GP I) on normal and pathological megakaryocyte (MK) precursors has been investigated in vivo and in a cell culture system with mouse monoclonal antibody (AN51) using immunofluorescence, immunogold and immunoferritin with electron microscopy. Our results confirmed the observation of Rabellino et al. (1979, 1981), using polyclonal antibodies, that GP I was expressed throughout normal MK maturation. The present result differs from our previous work which failed to detect binding of AN51 on promegakaryoblasts (PMKB). Improvement of immunofluorescent techniques has permitted detection of weak fluorescent labeling on normal PMKB by day 6-7 of in vitro culture from normal CFU-MK. An increased number of labeled PMKB was observed in bone marrow from patients with idiopathic thrombocytopenic purpura (ITP) as compared with normal bone marrow. In 20 selected cases of acute megakaryoblastic leukemia, AN51 labeled the PMKB but at a lower percentage than with J15 (monoclonal anti-glycoprotein IIb/IIIa complex). The MK nature of the blasts was confirmed by the ultrastructural detection of platelet peroxidase (PPO) and by the binding of AN51 demonstrated with immunoferritin-conjugated anti-mouse IgG. The immunogold technique revealed that the density of gold particles on the cell membrane of PMKB was variable, but generally weaker than in platelets or pathological micromegakaryocytes. The specificity of AN51 for MK lineage was shown by the absence of binding of AN51, by all blasts from 60 cases of acute leukemia involving other cell lines. Because of its weak labeling of PMKB due to the small number of antigenic sites, AN51 must be associated with another megakaryocytic marker in the diagnostic assessment of acute megakaryoblastic leukemia.

Acute Disease↗
PubMed1983

Myeloid and megakaryocytic properties of K-562 cell lines.

The expression of myeloid and megakaryocytic markers of differentiation has been studied in one K-562 cell subline, in its clones, and in the original cell line. Cytotoxicity, electron microscopy, immunofluorescence studies with a panel of polyclonal and monoclonal antibodies, and radioimmunoassays were performed on K-562 cells before and after induction with hemin, sodium butyrate, and 12-O-tetradecanoylphorbol-13-acetate. Myeloid membrane markers were present in all K-562 cell lines. Only the early granulopoietic cell surface markers were expressed in 75 to 95% of the cells, while none of the late membrane markers was detected. In contrast, neither the early (myeloperoxidase) nor late (lactoferrin) cytoplasmic markers were present. Thus, K-562 cells showed a membrane phenotype similar to that of a normal or leukemic promyelocyte but lacking myeloperoxidase. Membrane megakaryocytic markers, such as platelet glycoprotein IIIa and platelet peroxidase, were also detected in K-562 cells. However, some other early megakaryocytic markers, such as platelet glycoprotein lb, Factor VIII-R-Ag, and platelet Factor 4, could not be detected by fluorescent labeling. Cloning of the cell line did not result in the selection of a unipotential cell line. These results could be explained by the expression of multilineage markers in a single cell. In all of the cell lines and clones, hemin slightly increased the expression of the myeloid membrane markers without any modification of the megakaryocytic markers. Sodium butyrate and 12-O-tetradecanoylphorbol-13-acetate diminished most of the myeloid markers and very significantly increased the expression of the megakaryocytic markers.

Antibodies, Monoclonal↗
PubMed1982

Intracytoplasmic lysozyme in malignant hematologic disorders: an immunoperoxidase study.

Intracytoplasmic lysozyme was studied by the peroxidase antiperoxidase (PAP) and protein A-peroxidase methods in 130 cases of various myeloproliferative and lymphoproliferative disorders and 21 lymph nodes and bone marrow metastases from solid primary tumors. This marker, which can be identified in formalin or Zenker-fixed tissues, as well as in peripheral blood and bone marrow smears, proved useful to distinguish malignant myeloid and histiocytic tumors from malignant lymphoid and undifferentiated epithelial metastases. The diagnostic application of these findings are discussed.

Cytoplasm↗
PubMed1982

Multiple myeloma with a sarcoidosis-like reaction.

An unusual case of multiple myeloma with extramedullary dissemination and co-existing systemic non-necrotic granulomas is described. Immunoperoxidase staining revealed that both lymph node and bone marrow infiltrating plasma cells contained the same IgG-lambda type paraprotein, and that the granuloma epithelioid histiocytes contained intracytoplasmic lysozyme. As there was no evidence of either systemic infection or sarcoidosis, the non-necrotic granulomas may represent the host's response to the myeloma, not unlike the reaction observed in Hodgkin's disease or solid tumours. A causal association cannot, however, be entirely excluded.

Animals↗