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Query: UMLS:C0023418 (leukemia)
 93,477 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Cell susceptibility to agglutination mediated by a plant lectin, concanavalin A (Con A), and the binding capacity of Con A to cells following gamma-irradiation have been examined in mouse myeloid leukaemia cells cultured in suspension. Irradiation caused an immediate decrease in the amount of Con A bound to the cell surface, whereas susceptibility of irradiated cells to agglutination by Con A was unchanged when compared to that of the unirradiated cells. Post-irradiation incubation of cells at 37 degrees C resulted in a temporary, more than 1.3-fold increase in cell susceptibility to agglutination 60 min after irradiation, whereas binding capacity of cells for Con A gradually recovered following irradiation, reaching a comparable level to that of unirradiated cells 3 h after irradiation. Cell susceptibility to agglutination by Con A does not depend strongly on its binding capacity.
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PMID:Radiation-induced alterations in binding of concanavalin A to cells and in their susceptibility to agglutination. 348 53

The relative susceptibility of 10 human leukaemias comprising acute phase leucocytes from 5 acute myeloid and 5 lymphoid neoplasms, and 2 immunoblastic lymphomas to killing by peripheral blood mononuclear cells (PBMC), before and after target cell treatment with phytohaemagglutinin (PHA), and by interleukin-2 (IL-2) activated peripheral blood lymphocytes (PBL) was investigated in short term 51Cr release assays using effector cells from 10 allogeneic donors. Optimal lectin-dependent cellular cytotoxicity (LDCC) was verified against K562 and L1210 cells and lymphokine-activated killing (LAK) against K562 and Daudi cells. Under these conditions, the majority of the leukaemias tested revealed only a finite sensitivity to any of the cytotoxic mechanisms, which was dependent on the donor origin of the effectors. The leukaemias were more consistently susceptible to LDCC than LAK and removal of adherent cells to enrich for the latter activity in effector populations, was ineffective. Lymphocytes from a patient in long term (greater than 5 yr) remission exhibited LAK against the autologous target E84, a natural killer (NK)-sensitive acute myelomonocytic leukaemia. These cells failed to cross-compete for lysis of K562 by LAK cells, suggesting the existence of different recognition structure(s) on the two targets.
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PMID:Lymphokine activated killing of fresh human leukaemias. 348 7

Colony-stimulating factors (CSFs) are glycoproteins that stimulate the growth of hematopoietic progenitors and enhance the functional activity of mature effector cells. Human granulocyte/macrophage colony-stimulating factor (GM-CSF) is a 22-kDa glycoprotein that stimulates the growth of myeloid and erythroid progenitors in vitro and increases the responsiveness of neutrophils, monocytes, and eosinophils to physiologic stimuli. Elucidation of the cell and tissue sources of CSFs, as well as study of their regulation of expression, is required to understand their role in physiologic and pathophysiologic states. An extensive survey of normal and neoplastic human tissues did not reveal constitutive production of detectable levels of GM-CSF mRNA in any of the 64 samples studied. Antigen- or lectin-activated T lymphocytes have been shown to produce GM-CSF; therefore, to elucidate the genetic sequences required, we constructed recombinant plasmids containing 5' flanking DNA of the GM-CSF gene linked to the marker chloramphenicol acetyltransferase gene. The recombinant constructs were transfected into a human T-cell leukemia virus type I (HTLV)-infected T-lymphoblast cell line that can be stimulated to produce high levels of GM-CSF. We show here that the 5' flanking sequences of the GM-CSF gene can direct increased expression of the chloramphenicol acetyltransferase gene in activated T-lymphoblast cells.
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PMID:Regulation of expression of human granulocyte/macrophage colony-stimulating factor. 349 Jun 69

The expression of blood group A antigen on marrow and blood cells from A1 and A2 subjects was investigated by the binding of Helix pomatia and Dolichos biflorus lectins using immunofluorescence. These two lectins stained BFU-E-derived colonies from A subjects in the early days of culture before the expression of glycophorin. The erythroid origin of these cells was ascertained by the coexpression of two other very early erythroid markers. In bone marrow, the ultrastructural immunogold method revealed that the entire erythroid lineage including proerythroblasts was labeled by HPA, whereas no staining was observed on granulomonocytic cells including myeloblasts. Platelets from A subjects were HPA-labeled and so were platelets from an O subject preincubated in A plasma. Megakaryocytes obtained in CFU-MK-derived colonies were weakly and heterogeneously labeled by the HPA lectin. Cultures from A1 and A2 subjects were the reflection of the genetic differences only when investigations were performed on mature erythroblasts. In contrast, the great majority of immature erythroblasts both from A2 and A1 subjects were equally labeled by both lectins; during further erythroid maturation, binding of both lectins markedly diminished only on A2 erythroblasts. When marrow erythroblasts were investigated at electron microscopic level, heterogeneity of labeling among all stages of maturation was clearly observed in A2 subjects, with staining stronger on immature than on mature erythroblasts. Therefore, the genetic differences between A1 and A2 subjects are revealed during terminal erythroid differentiation.
Leukemia 1987 Jan
PMID:Expression of blood group A antigen during erythroid differentiation in A1 and A2 subjects. 366 34

A tumor antigen (TA) associated with murine leukemia-lymphoma L5178Y cells has been identified by the enzyme-linked immunosorbent assay (ELISA) and indirect immunofluorescence (IIF) techniques. The antigen was present in both non-solubilized and 0.5% NP-40 solubilized membrane extracts. Rabbit anti-L5178Y lymphoma serum (RALS), extensively absorbed with normal mouse tissues, identified TA in extracts of L5178Y lymphoma and L5178Y leukemia cells grown in horse serum (L5178Y/HS), but not in extracts of L5178Y cells grown in fetal calf serum (L5178Y/FCS). Similarly, absorbed rabbit anti-L5178Y/HS serum specifically reacted with extracts of lymphoma and L5178Y/HS but not with L5178Y/FCS cells. Membrane IIF showed positive reactivity in 88% of lymphoma and 73% of L5178Y/HS cells, whereas splenic lymphocytes and L5178Y/FCS cells were negative. Goat anti-AKR virus serum reacted with soluble extracts of lymphoma, L5178Y/HS, and L5178Y/FCS as well as with normal DBA/2 tissues in the ELISA. However, goat anti-AKR virus serum did not block the reactivity of RALS to lymphoma in the blocking ELISA (BELISA). Expression of TA, but not murine leukemia viral antigen(s), was correlated with the in-vivo tumorigenicity of the L5178Y cells. The antigenic activity of lymphoma extract was reduced by incubation for 1 h at 56 and 65 degrees C, by trypsin digestion, and by exposure to pH 2.8 or 11.0 for 1 h. The antigen, sequentially purified by gel filtration and Lentil-lectin affinity chromatography, was a glycoprotein, with a molecular weight of approx. 64,000 daltons, as determined by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) analysis.
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PMID:Effects of horse and fetal calf serum on the expression of tumor-associated antigen and tumorigenicity of L5178Y leukemia/lymphoma cells. 379 35

The bacterially fermented mistletoe preparation Iscador, used in cancer therapy for 30 years, and the recently prepared unfermented preparation, have been tested on rat hepatoma tissue culture (HTC) cells and human leukemia Molt 4 cells. As observed by phase-contrast microscopy, treatment of HTC cells with fermented or unfermented Iscador, at a concentration corresponding to 1 mg of fresh plant per milliliter culture, led to rapid lysis of cellular membranes. At a lower concentration, 0.1 mg/ml, unfermented Iscador led to the formation of polynucleated cells. On Molt 4 cells, fermented Iscador also produced cytolysis but after a longer time of action. Unfermented Iscador showed a much stronger cytotoxic effect on these cells than on HTC cells. Fermented Iscador was slightly more potent than unfermented Iscador in inhibiting the growth of HTC cells, but on Molt 4 cells fermented Iscador was less active than unfermented Iscador. DNA synthesis, measured by [3H]thymidine incorporation in HTC and Molt 4 cells, was inhibited by fermented and unfermented Iscador with the same type of differences of action as on cell growth. Fermented Iscador contained a low amount of lectins, approximately 100 ng/ml, while unfermented Iscador contained about 10 times more. A purified mistletoe lectin produced effects on HTC and Molt 4 cells similar to those of unfermented preparations. HTC cells were 100 times less sensitive to this lectin than Molt 4 cells. These results are discussed in relation to the known biological effects of lectins.
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PMID:Comparison of the effects of fermented and unfermented mistletoe preparations on cultured tumor cells. 380 75

Trichosporon capitatum was isolated from the blood of two patients with acute leukaemia who were undergoing induction chemotherapy. Both patients died of their infections, and the fungus was cultured from their tissues after death. Systemic infection was proved by demonstrating the same pattern of fluorescein-labelled lectin staining of fungal elements in the tissues as was shown by the fungal isolates.
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PMID:Systemic infection with Trichosporon capitatum in two patients with acute leukaemia. 385 76

High level of tyrosine protein kinase activity was found in a membrane fraction isolated from an acute myeloblastic leukemia, out of 24 leukemias of different origin investigated. The major substrate for tyrosine phosphorylation in vitro was a 58 kDA protein (p58). The phosphorylation proceeded actively at 0 degrees C and was strongly stimulated by Mn2+ ions. Comparison by partial proteolysis of the p58 with similar phosphoproteins from a T-lymphoma line (KE37) and from lectin stimulated lymphocytes showed high similarity. The possible role of the tyrosine kinase activity in this leukemia is discussed.
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PMID:Acute myeloblastic leukemia with active tyrosine protein kinase. 386 16

An in vitro study of the behaviour of a human acute lymphoblastoid leukemia cell line (REH) towards the action of a mitogenic lectin of Robinia pseudoacacia was carried out. The results were compared with those a reference cell line (LHN13) established from normal human lymphocytes. In both cell lines, the lectin induces agglutination (measured by counting the number of aggregates as well as the number of cells in each aggregate) and decrease of growth (measured by counting the number of cells and the incorporation of tritiated thymidine into TCA-precipitable material per 10(6) cells). The agglutination and the decrease of growth are produced at the doses of 0.5 and 1 microgram/ml of culture medium and after 4 h of exposure of cells to the lectin, respectively. These effects increase progressively with higher doses of lectin and continues throughout the culture. However, the REH line is less sensitive than the LHN13 line to the effects of lectin. Both agglutination and growth decrease of REH as well as LHN13 cell lines by the lectin are reversible; this is confirmed by the fact that the monospecific anti-Robinia lectin serum suppresses these effects.
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PMID:In vitro study of the comparative behaviour of a human acute lymphoblastic leukemia cell line and a reference normal cell line towards the effects of a mitogenic lectin. 386 37

This report discusses a case of T cell chronic lymphocytic leukemia (T-CLL) in an elderly white man whose lymphocytes expressed a post-thymic phenotype except for the coexpression of T4 and T8 on 80% to 95% of the cells. Because of the uncommon phenotype, in vitro functional assays were performed that showed decreased mitogenic responses but normal helper activity for B cell immunoglobulin secretion and normal suppressor activity of lectin-induced mitogenesis. Morphologic evaluation by both light and electron microscopy and cytochemical staining were consistent with the "knobby" type T-CLL. Adenosine deaminase and terminal deoxynucleotidyl transferase (TdT) levels were low, but the acetylcholinesterase level was normal, which is consistent with the peripheral T cell phenotype. The patient underwent splenectomy, and the spleen cells showed very low levels of T3 and T4 by immunoperoxidase and undetectable levels by immunofluorescence. The morphology of the splenic infiltrate was not significantly different from that in the initial bone marrow. Human T cell leukemia virus (HTLV) antigen and antibody tests were negative. The cells in this leukemia apparently are derived from a transitional stage of maturation between the cortical and medullary thymocyte. A small subset of lymphocytes of identical phenotype to this leukemia has been identified in normal individuals.
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PMID:T cell chronic lymphocytic leukemia with lymphocytes of unusual immunologic phenotype and function. 387 Nov 60


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