Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:1.11.1.7 (peroxidase)
 65,474 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The phagocytosis (in the absence of serum factors) of zymosan particles by peripheral leukocytes isolated from ten patients with acute leukemia (AMbL, AMoL, AMML, AUL, ALL and CML-BC) was studied at the electron microscope. An evident phagocytic activity was observed only in the cells in which cytochemical and ultrastructural features suggested that the blast elements belonged to the monocytic series. However, no phagocytosis by unclassifiable leukemic blasts was observed, even though they had some submicroscopic characteristics of the monocytic series. These findings suggest that phagocytic capacity develops during the course of cell differentiation, becoming striking only when the blast cell acquires the ultrastructural features of the pro-monocytic stage. Using the myeloperoxidase reaction, this study also demonstrates a morphological alteration in the degranulation process after the ingestion of zymosan particles in both the blasts and the mature PMN cells of leukemic patients. This defect could be related to the susceptibility to severe infections usually found in subjects with hematological malignancies.
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PMID:Ultrastructural study of leukemic cell phagocytosis using the myeloperoxidase reaction. 22 98

The stereologic characteristics of monocytes from patients with acute nonlymphocytic leukemia containing a monocytic component (FAB M4 and M5), and the monocytes from normal individuals were determined by morphometric analysis. The cells studied were monocytic cells beyond the promonocyte stage of development, as defined by ultrastructural criteria. Parameters evaluated included cell and nuclear volumes and surface areas, mitochondrial and myeloperoxidase (MPO)-positive secretory granule volume and numerical density as well as volume and number of the organelles/cell. Peripheral blood and bone marrow monocytes of leukemic patients could not be distinguished by their cell or organelle stereologic characteristics. Monocytes from patients with both M4 and M5 acute leukemia had relatively large cell and nuclear volumes. Mitochondrial volume density and volume/cell were also high in monocytes from leukemic patients (M4; 21 microns 3/cell, M5 20 microns 3/cell) as compared with monocytes from normal individuals (8.5 microns 3/cell). On the other hand, MPO-positive secretory granule stereologic parameters in monocytes from leukemic patients were indistinguishable from those of normal individuals. A small number (3 of 18) patients showed very low monocyte MPO-positive granule volume densities. There was a slight positive correlation between MPO-positive granule volume density and patient survival time. No relationship between mitochondrial characteristics and survival was noted.
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PMID:Stereologic analysis of monocytes and their subcellular organelles in patients with acute monocytic and myelomonocytic leukemia. 239 34

We reported a 68-year-old woman with acute nonlymphocytic leukemia, in whom the leukemia transformed from poorly differentiated myeloperoxidase (MPO)-negative type into myelomonocytic type during the observation without chemotherapy. Hematological findings on admission revealed a leukocyte count of 3,500/microliters with 48% blasts and a platelet count of 9.2 x 10(4)/microliters. Bone marrow aspiration showed 68.2% infiltration of blasts negative for MPO. Sudan black B and esterase stains. By electron microscopy MPO was detected in the endoplasmic reticulum and nucleoenvelope of the blasts. Large vacuole-like granules were MPO-negative. She was observed without administration of any antileukemic agent or an immunopotentiator. The leukocyte count rose gradually, in association with increases in the relative and absolute counts of mature neutrophils and monocytic cells, and the platelet count. Twenty-six months after the initial diagnosis, a blood examination showed a leukocyte count of 74,300/microliters with 20.5% mature neutrophils and 15.5% monocytic and a platelet count of 31.4 x 10(4)/microliters. Cytological, cytochemical, ultrastructural and immunological studies of the bone marrow cells showed features compatible with acute myelomonocytic leukemia (FAB M4). This case is unusual in respect that poorly differentiated ANLL transformed spontaneously into moderately differentiated ANLL.
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PMID:[Spontaneous differentiation from myeloperoxidase-negative acute nonlymphocytic leukemia to acute myelomonocytic leukemia]. 255 92

This thesis is a survey of nine previously published articles on MPO deficient PMN. The incidences in leukaemia and allied disorders of the presence of this abnormal subpopulation of mature neutrophils and the relationship to clinical course in AML, susceptibility to infections in AML, FAB classification in AML and MDS, cytogenetically defined aberrations in MDS and morphometrical characteristics were investigated. The aims of the studies were to examine the diagnostic as well as the prognostic value of the parameter, to examine the usefulness of the parameter as an predictive indicator of CR and relapse in AML and to examine the concept that MPO deficient PMN may originate from leukaemic precursors. MPO deficient PMN were found to occur in a minor number (less than 4% of the total number of PMN) in normal humans and the incidences of an abnormal number (greater than 4%) were found to be about 40% in AML (I, II, III, IV, VIII), 60% in CML (I, VII), 30% in MPD other than CML (VII) and 30% in MDS (V). The highest incidences in AML were found in the FAB subtypes possessing the most myeloid differentiation potential i.e. FAB M2 and FAB M4 (IV). In ALL, CLL, HCL, Hodgkin's disease, anaemia not related to leukaemia and leukaemoid reactions the incidences all were 0% (I, unpublished data). The abnormal MPO deficient PMN subpopulation, if present, disappeared when CR was achieved and reappeared when relapse eventually was developed (II, VIII). In both situations serial determinations showed that the change occurred before the usual routine blood examinations predicted CR and relapse; several days and several months prior, respectively (VIII). The probability of obtaining CR was lower in the AML patients with the abnormal subpopulation and the risk of developing relapse higher than in AML patients without the anomaly (II, VIII). These differences were not statistically significant, however. AML patients, showing an increased number of MPO deficient PMN, revealed a statistically significant increased susceptibility to infections (P less than 0.01) during the preremission phase accounting for 18% to 67% of the total number of infections in this period (III). This increase was positively correlated to the extent of the anomaly (P less than 0.002). The spontaneous occurrence of a subpopulation of MPO deficient PMN in MDS went together with a simultaneous progression in cytogenetically determined clonal chromosomal aberrations and were related to progression in FAB subtype as well (VI). Morphometrically MPO deficient PMN were characterized by a decreased total cell size and an increased nucleus size of the projected images (IX).(ABSTRACT TRUNCATED AT 400 WORDS)
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PMID:Myeloperoxidase deficient polymorphonuclear leucocytes in leukaemia and allied disorders. 285 15

We investigated the light and ultrastructural morphology of 37 patients with acute nonlymphocytic leukemia (ANLL) and inv(16)(p13q22) or del (16)(q22) with specific emphasis on the changes in the eosinophils (EOS). All but one of the 37 patients were classified as French-American-British M4 with eosinophilia (FAB M4-E) on the basis of the monocytoid nature of the leukemic cells and the presence of large EOS with interspersed basophilic-staining granules. A median of 92% of the blasts were peroxidase positive, and Auer rods were found in 71% of cases. Only 27% of the cases had sufficient alpha-naphthyl butyrate positivity to confirm the diagnosis of FAB M4, but electron microscopy demonstrated a sufficient monocytic component to support this classification in all cases examined. Electron microscopy also demonstrated nuclear blebs both in the blasts and notably, in the EOS of all cases examined (16 of 16). Nuclear blebs in EOS were found in only 1 of 13 cases of ANLL that showed eosinophilia but lacked abnormalities of chromosome 16. This case was also classified as FAB M4-E. The finding of nuclear blebs in EOS in FAB M4-E suggests that the EOS may be derived from the malignant clone in this leukemia. These blebs are also of diagnostic in value classifying a leukemia as FAB M4-E.
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PMID:Acute myelomonocytic leukemia associated with abnormalities of chromosome 16: a light and electron microscopic study. 350 32

The rat monoclonal antibody CAMPATH-1 recognizes a hitherto undefined antigen present on virtually all normal lymphocytes and monocytes. Its reactivity with 105 samples of fresh leukaemic cells and 13 cell lines was measured by indirect fluorescence and peroxidase staining to define in more detail which stages of differentiation it recognizes. It was found to bind to cells from virtually all cases of lymphoid leukaemia (B cell CLL, T cell ALL, cALL and the few examples of HCL, PLL, Sezary syndrome and CGL in lymphoid blast crisis). The single case of cALL in relapse and four of six cases of null ALL were negative. Binding to non-lymphoid leukaemia cells (AML, AMML, AMoL, APL, AEL and CGL in blast crisis) was weaker or undetectable. Binding to established lymphoid cell lines was generally weak compared with fresh cells but some lines (MOLT4, DAUDI and X308) expressed adequate amounts of antigen to be lysed by CAMPATH-1 with human complement. Because CAMPATH-1 is very effective at killing lymphocytes in the presence of human complement, it has been used for removal of T cells in allogeneic transplants. The present results suggest that it might also have a role in purging bone marrow of leukaemia cells prior to autologous transplantation for acute lymphocytic leukaemia.
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PMID:Reactivity of rat monoclonal antibody CAMPATH-1 with human leukaemia cells and its possible application for autologous bone marrow transplantation. 389 Sep 29

Fifteen of 73 newly diagnosed patients with acute myeloid leukemia (AML), admitted to Mount Sinai Hospital between July 1977 and October 1979, presented with leukocyte counts greater than 100,000/microliter. Eleven of these 15 patients with hyperleukocytosis had myelomonocytic (AMML-M4) or monocytic (AMOL-M5) leukemia compared to 15 of 58 patients with lower white cell counts (p < 0.001). Identification of type of leukemia, using the FAB classification, was based on morphology and special stains, including myeloperoxidase, Sudan black B, periodic acid-Schiff and nonspecific esterase with and without inhibition by fluoride. The proportion of patients with splenomegaly is higher in those with hyperleukocytosis (73 percent) than in those with lower white blood cell counts (p < 0.001) regardless of cell type. Leukemic infiltration of the skin, gums and central nervous system was seen exclusively in patients with AMML and AMOL. The serum lysozyme levels were significantly higher for all patients with AMML and AMOL regardless of the white blood cell count. The mean serum lysozyme for M-4, M-5 patients was 59.7 microgram/ml compared to 18.9 microgram/ml in patients with other cell types (p < 0.0001). Patients with a white blood cell count less than or equal to 100,000/microliter had a complete remission rate of 69 percent compared to 47 percent for patients with higher white blood cell counts.
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PMID:Association of monocytic leukemia in patients with extreme leukocytosis. 693 15

The behaviour of phagocytosis and that of PGE1 and PGE2 in the circulating granulocytes of normal and leukaemic subjects was investigated by the comparison of latex particles and the PAP (peroxidase-antiperoxidase) immuno-enzymatic method respectively. Generally speaking, it was found that chronic myeloid leukaemia and acute myeloblastic leukaemia were accompanied by a marked reduction in phagocyting capacity, whereas this is apparently normal in CLL and ALL. PCE values, on the other hand, were well down in lymphatic leukaemia, AML and AMML, but not in CML, where high PGE (especially PGE2) was noted both basally and after phagocytosis. That the PGE take part in phagocytosis is shown by their redistribution in phagocyting cells, with elective accumulation in the membrane and around the engulfed material.
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PMID:[Behavior of PGE1 and PGE2 in the granulocytes of normal and leukemic subjects during phagocytosis in vitro]. 695 84

Human permanent leukemia cell lines represent powerful research tools in a multitude of investigations. The two new continuous leukemia cell lines MUTZ-2 and MUTZ-3 were derived from the peripheral blood of patients with acute myeloid leukemia (AML) FAB M2 and AML FAB M4. MUTZ-2 and MUTZ-3 cells have morphological and immunophenotypical features of myeloid and monocytic cells, respectively. While MUTZ-2 is negative, MUTZ-3 cells express the monocytic surface marker CD14, albeit weakly. The monocytic nature of MUTZ-3 cells is underlined by the expression of the monocyte-specific esterase (MSE), myeloperoxidase (MPO) and tartrateresistant acid phosphatase (TRAP) enzymes; MUTZ-2 is negative for MSE and TRAP, but expresses MPO. For sustained cell growth, both cell lines require constitutively the addition of cytokines to the culture medium and retain an absolute dependence on conditioned medium or recombinant growth factors for proliferation and survival. Incubation with single recombinant cytokines from a broad spectrum of growth factors established that the strongest proliferation response of MUTZ-2 cells was elicited by FLT-3 ligand, granulocyte colony-stimulating factor (G-CSF), macrophage CSF (M-CSF), interferon-gamma (IFN-gamma) and stem cell factor (SCF), whereas granulocyte-macrophage CSF (GM-CSF), M-CSF, interleukin-3 (IL-3) and SCF were the most effective growth factors in inducing proliferation of MUTZ-3. Both cell lines were proliferatively responsive to several further cytokines, however, to a lesser extent. Exposure to phorbol ester 12-O-tetradecanoyl-phorbol-13-acetate (TPA) or the physiological all-trans retinoic acid (ATRA) had growth-inhibitory and differentiation-inducing effects on both cell lines. Using a clonogenic cell recovery assay, both cell lines were found to be sensitive to the chemotherapeutic drugs cytosine arabinoside (Ara-C) and daunorubicin (DNR), MUTZ-2 cells being more sensitive to both Ara-C and DNR treatment than MUTZ-3 cells. Chromosomal trisomies 8 and 10 were found in MUTZ-2 cells without any additional structural abnormalities. MUTZ-3 carries the rare, but recurrent AML-associated translocation (12;22)(p13;q11-q12) reflecting the karyotype of the original tumor. The main characteristics of these cell lines remained the same during about 1 year of continuous culture as well as after freezing and thawing. In summary, we established and characterized two new leukemia cell lines with myeloid or monocytic features which are growth factor-responsive, one of them carrying a unique chromosomal translocation. These cells will be of particular value for investigating the complex cytokine network and molecular events caused by chromosomal aberrations.
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PMID:Establishment and characterization of two novel cytokine-responsive acute myeloid and monocytic leukemia cell lines, MUTZ-2 and MUTZ-3. 866 38

A patient is described with myelodysplastic syndrome (MDS) progressing to acute myeloid leukemia (AML) FAB M4. Cytogenetic analysis revealed an unusual rearrangement between chromosomes 9 and 17, leading to a dicentric chromosome with an insertion of material of unknown origin between both chromosomes. By fluorescence in situ hybridization (FISH), the insertion was shown to be an amplification of part of 17q, involving ERBB2, RARA, and TOP2A genes. The median copy number of ERBB2, RARA, and TOP2A genes in the tumor cells was six (range: 4--10). Only one copy of the MPO gene at 17q21.3 was detected, suggesting a deletion of the telomeric part of 17q. To our knowledge, this is the first report of a 17q amplification in AML.
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PMID:Amplification of ERBB2, RARA, and TOP2A genes in a myelodysplastic syndrome transforming to acute myeloid leukemia. 1142 59


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