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

The cytotoxic effect of spleen cells from H-2 allogeneic mice was tested in vitro against an A strain leukemia (YAC) labeled with [(125)I]iododeoxyuridine. After the mice were primed with tumor cells, significant and specific H-2 immunity was detected on day 3 and peak cytotoxicity was observed between 7 and 14 days after priming. Two effector cells appear to be involved in the host response, because spleens taken from mice soon after priming were not sensitive to antitheta sera and complement while those taken during the peak stages of the response showed a marked reduction in cytotoxicity after treatment. Macrophages were not involved, since removal of these cells by the carbonyl iron method did not result in any reduction in cytotoxicity. Immune serum that was capable of inducing cell-mediated cytotoxicity in normal spleen cell populations also augmented cytotoxicity of spleen cells taken from mice primed 3 days previously. However, when spleen cells were taken from mice during the peak phase of the immune response, the same serum at the same dilutions inhibited the preexisting cytotoxicity. A difference was also detected in the killing efficiencies between early and late immune cells.
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PMID:Heterogeneity of the effector cells in the cytotoxic reaction against allogeneic lymphoma cells. 453 47

Adult BALB/c mice were injected with Moloney sarcoma virus (MSV) after which the animals' lymphocytes were examined for activity against Moloney leukemia virus (MLV) antigen-bearing target cells at 5-day intervals for 30 days. Lymphocytes from these animals and appropriately matched controls were fractionated into B cell-deficient (primarily T cells) and T cell-deficient (primarily B cells) subpopulations. Macrophages were removed using iron powder and magnetism. The unfractionated lymphocytes, T cells, and non-T cells were then tested in microcytotoxicity tests. Antigen-specific activity was found in the unfractionated lymphocytes from animals that had not yet developed palpable tumors and from regressor animals. The T cells were active just before tumor development and just after regression; however, by day 30 after virus infection (8-10 days after regression) the T cell subpopulation was much less active. The non-T cell subpopulation was also active before tumor development and soon after regression. However, this activity continued to rise after regression and was highest at 30 days. At day 15 (peak tumor size) neither subpopulation was active. The activity was demonstrated to be specific for the MLV-determined cell surface antigen by testing on control target cells that were MLV antigen negative and by comparison of the inhibitory effects with lymphocytes immune to a nonpertinent antigen as well as normal lymphocytes. The non-T cells were tested for activity before and after removal of macrophages with iron powder and magnetism. Such cells were significantly more active after removal of the macrophages. These data demonstrate specific T cell and non-T cell activity in microcytotoxicity tests with a tumor-specific system and strongly suggest that the non-T cell activity described herein is a B cell function.
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PMID:The lymphocyte response to primary Moloney sarcoma virus tumors in BALB-c mice. Definition of the active subpopulations at different times after infection. 470 69

Erythropoiesis during the development of myeloid leukaemia in mice was studied, using assay of radio-iron incorporation in blood, exorepopulation and autorepopulation techniques. These tests indicated a certain tendency of decreasing erythropoiesis during the leukaemic process due to declining numbers of the normal erthropoietic cell precursors.
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PMID:Erythropoiesis in murine myeloid leukaemia. 492 Feb 17

Monolayer cultures of ARH-77 cells, a human myeloma cell line propagated in vitro, display a variety of morphologic entities ranging from small lymphocytes to classic plasma cells. The cells show intense pyronin and periodic acid-Schiff affinity but are negative for colloidal iron, sudan black, and naphtol AS-D chloroacetate esterase. The cells exhibit phenotypic markers pertaining to each stage of the B-cell lineage. They fail to display sheep erythrocyte and bovine erythrocyte-IgG antibody complex rosettes, common acute lymphocytic leukemia (ALL) antigens and T-cell antigens, but most cells display surface complement receptors, Ia-like antigens, and surface and intracytoplasmic Ig. Monoclonal antibodies were negative for T-antigens, myelomonocytic cell antigens, leukemia-associated antigens, and BA-1 and OKT-10 antigens. However, 100% of the cells were positive with OKT-9 and B3/25 antibodies that are specific for transferrin receptors. About 50% to 80% of the cells were positive for surface membrane immunoglobulin (kappa IgG) and about 10% to 50% for cytoplasmic immunoglobulin (kappa IgG). Virtually all cells were positive when tested for nuclear Epstein-Barr virus antigens.
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PMID:ARH-77, an established human IgG-producing myeloma cell line. I. Morphology, B-cell phenotypic marker profile, and expression of Epstein-Barr virus. 609 3

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.
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PMID: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. 609 46

Fe(III) complexes of EDTA and diethylenetriamine pentaacetic acid (DETAPAC) at low concentrations (between 1 and 100 microM) produced up to a 20-fold increase in anaerobic microsomal NADPH- and NADH-dependent reduction of indicine N-oxide. Under aerobic conditions microsomal indicine N-oxide reduction was stimulated to half the levels seen under anaerobic conditions. EDTA alone was much less effective at stimulating indicine N-oxide reduction, while FeCl3 alone had no effect on reduction. Other complexes of Fe(III) had little or no effect in stimulating microsomal indicine N-oxide reduction. Fe(III)-EDTA stimulated indicine N-oxide reduction by purified NADPH-cytochrome P-450 reductase and NADPH. It is probable that iron serves to transfer electrons between microsomal flavoprotein reductases and indicine N-oxide. The redox potential and the presence of an exchangeable ligand, such as water, in the inner ligand sphere of the iron complex are suggested to be important factors in determining which iron complexes will stimulate indicine N-oxide reduction. EDTA complexes of other transition metal ions do not stimulate indicine N-oxide reduction. Hydroxyl radicals, detected as the spin adduct of 5,5-dimethyl-1-pyroline-N-oxide, appear to be formed during Fe(II)-EDTA-dependent reduction of indicine N-oxide under anaerobic conditions. Fe(III)-EDTA at concentrations between 50 and 250 microM stimulated indicine N-oxide reduction by rat isolated hepatocytes up to 5-fold under anaerobic conditions and to half these values under aerobic conditions. By themselves, EDTA and FeCl3 at similar concentrations produced a small stimulation of indicine N-oxide reduction by hepatocytes under anaerobic conditions. Fe(III)-EDTA stimulated indicine N-oxide reduction by murine leukemia P-388 cells under aerobic conditions and by rat caecal flora under anaerobic but not aerobic conditions. Fe(III)-EDTA, EDTA or FeCl3 administered to rats produced a 3-fold increase in the 24-hr urinary excretion of indicine following an i.p. dose of indicine N-oxide.
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PMID:Iron-EDTA stimulated reduction of indicine N-oxide by the hepatic microsomal fraction, isolated hepatocytes, and the intact rat. 628 Jul 24

Erythrocyte survival and ferrokinetic studies were adapted to the cat. For 5 clinically healthy 4- to 9-month-old cats, mean 51Cr-labeled erythrocyte survival was 144 hours, and mean plasma 59Fe-labeled transferrin disappearance halftime was 51 minutes. Erythrocyte use of radioiron was rapid and efficient, with 50% to 80% of labeled iron incorporated into the erythron by 100 hours after injection into the cat. Six cats with feline leukemia virus infection were studied. For 2 cats with erythroid aplasia associated with C subgroup of feline leukemia virus, erythrocyte survival times were similar to those determined for the healthy cats, but plasma radioiron disappearance half time and erythrocyte use of radioiron were markedly diminished.
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PMID:Ferrokinetic and erythrocyte survival studies in healthy and anemic cats. 630 16

Backscattered Electron Imaging (BEI) is a particular technique which permits to study cytochemical reactions with the Scanning Electron Microscope (SEM). The BEI data pertaining to specific enzymatic activities can be directly correlated to the surface morphology of each individual cell. Leukocytes from 5 normal individuals, 14 patients with acute nonlymphoblastic leukaemia (ANLL), 7 patients with chronic myeloid leukaemia (CML) and 3 patients with acute lymphoblastic leukaemia (ALL) were studied for myeloperoxidase activity, acid phosphatase localization, silver staining of the nuclei and phagocytosis of iron carbonyl in the BEI mode of SEM. Some normal peripheral blood leukocytes which cannot be distinguished by their surface morphology alone were satisfactorily identified with the BEI technique. Leukaemic myeloid cells can be recognized in many cases because of their positive myeloperoxidase reaction, while monocytic elements can be characterized by the presence of surface ruffles, acid phosphatase activity and active phagocytosis. The usefulness of the BEI technique in identifying different blood cell types with the SEM and its possible application to the diagnosis of certain cases of leukaemia are discussed.
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PMID:Scanning electron microscope cytochemistry of normal and leukaemic leukocytes. 632 37

A series of iron chelating agents including the bacterial siderophores, parabactin and bis-N1,N8(2,3 dihydroxybenzoyl )spermidine, and four related compounds were synthesized and tested biologically. They were found: (a) to inhibit growth of cultured L1210 leukemia cells at IC50 values of 2-14 microM, (b) to inhibit replication of the DNA virus, herpes simplex type I, in monkey kidney cells at IC50 values of 0.4 microM ( parabactin ) to 55 microM, and (c) to be inactive against the RNA virus, vesicular stomatitis, at concentrations up to 1 mM. All effects were fully preventable by exogenous Fe (III). The activities correlated generally with the iron formation constants (10(36) to 10(48) moles/1) and more specifically with the lipophilicity of the compounds. The data suggest inhibition of DNA (but not RNA) synthesis by interference with the iron-containing enzyme, ribonucleotide reductase.
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PMID:Antineoplastic and antiherpetic activity of spermidine catecholamide iron chelators. 633 31

Patients with leukemia were found to have a high percentage of saturation of their serum transferrin with iron to an extent only rarely observed with other malignancies. This was associated with a reduced ability of their serum to inhibit the growth of a test strain of Pseudomonas aeruginosa. Serum iron, transferrin, and related parameters were measured serially in patients undergoing bone marrow transplantation for leukemia or aplastic anemia. It was found that a high proportion of these patients also have a high saturation of their transferrin with iron. This was related to three distinct physiologic deficits: a low level of serum transferrin; a high level of iron; and an inability to reduce the level of serum iron during infection. Three of six patients who were unable to reduce their serum during fever and infection subsequently died of sepsis. These data support the hypothesis that derangements in nonspecific serologic defense mechanisms involving iron contribute to susceptibility to infection in patients with leukemia undergoing bone marrow transplantation.
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PMID:Transferrin in disease II: defects in the regulation of transferrin saturation with iron contribute to susceptibility to infection. 637 46


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