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)

A search for immunoglobulin deposits in normal and fibrous interstitial tissue was carried out on 100 bone marrow biopsies (44 myeloproliferative disorders and 56 other hemopathies). This preliminary study enabled one to draw three conslusions: 1) The search for immunoglobulins is only possible on non-decalcified bone marrow. The direct immunofluorescent technique gives better results than peroxidase staining: 2) In myeloproliferative disorders immunoglobulins (especially G) are more frequent and more often associated with a myelofibrosis than in other hemopathies, and 3) The more pronounced the fibrosis the more frequent the immunoglobulin deposits, except at the osteomyelosclerosis stage. They are never found in the fibrosis secondary to intramedullary carcinomatous metastases.
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PMID:Histo-immunology of myelofibrosis: a study of 100 cases. 35 22

Chronic granulocytic leukemia is a rare myeloproliferative disorder in dogs. The present study investigated various functions of leukemic granulocytes in a dog that presented with thrombocytopenic purpura, anaemia and a classical leukemic hemogram. All analyses were performed in parallel with a control dog. Purification of the leukemic granulocytes by density gradient centrifugation revealed three neutrophil and neutrophil precursor populations with different densities. Comparison of cell morphology and density showed that cell density increased with increasing maturity. The control dog possessed only one neutrophil population, with a density greater than 1.077. Analysis of cellular contents of the granular enzymes, elastase, myeloperoxidase and lysozyme showed that leukemic neutrophils were quantitatively markedly different from normal neutrophils with respect to enzyme activities. There were no major differences between leukemic and normal cells as regards aggregatory and migratory responses to different stimuli. The phagocytic capacity of the leukemic cells, however, was dramatically increased compared with the control, and exceeded all previously encountered responses in the assay employed. In a similar fashion, superoxide generation and secretion of elastase and lysozyme in response to zymosan and phorbol myristate acetate were substantially higher than in the control dog. Priming of cell function to a level exceeding that normally attainable in neutrophils appears to have taken place in peripheral blood of the leukemic dog. The only endogenous mediator known to prime neutrophil functions to the extent seen in the present case is the cytokine granulocyte-macrophage colony-stimulating factor (GM-CSF), which is intimately involved in regulation of myelopoiesis in mammals. On the basis of the enzymological and functional findings in the leukemic dog, we hypothesize that a lactoferrin deficiency in leukemic neutrophils leads to enhanced GM-CSF synthesis, which is ultimately the cause of the observed cellular hyperresponsiveness and contributes to the monocytosis seen in the patient.
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PMID:Enhanced granulocyte function in a case of chronic granulocytic leukemia in a dog. 165 Oct 30

Immunohistochemical detection of intracellular myeloperoxidase, a major constituent of primary granules of neutrophilic myeloid cells, was determined in paraffin sections of 161 specimens using a rabbit polyclonal antibody to human myeloperoxidase and an indirect immunoperoxidase technique. In normal tissues and in a variety of myeloproliferative disorders, myeloid cells of both neutrophilic and eosinophilic types, at all stages of maturation, exhibited strong cytoplasmic reactivity for myeloperoxidase. Myeloperoxidase was readily detected in myeloblasts and immature myeloid cells of acute myelogenous leukemia, progranulocytic leukemia, monomyelocytic leukemia, erythroleukemia, myeloblastomas, and other hematopoietic disorders. Erythroid precursors, megakaryocytes. other hematopoietic disorders. Erythroid precursors, megakaryocytes, lymphoid cells, mast cells, and plasma cells were nonreactive. Cells of monocytic derivation revealed variable reactivity and were typically weakly positive or nonreactive. In a few specimens, rare histiocytes were reactive, some possibly due to phagocytosed material. Cells comprising the infiltrate of a spectrum of lymphoid malignancies, e.q., lymphoblastic lymphoma or leukemia, chronic lymphocytic leukemia, hairy cell leukemia, non-Hodgkin's lymphomas of T- or B-cell type, and Hodgkin's disease, were nonreactive, as were the non-neoplastic tissues present in these specimens, except for occasional cells of myeloid derivation. Myeloperoxidase was not observed in the neoplastic cells of a wide variety of epithelial tumors and sarcomas, or in the contiguous non-neoplastic tissues. Immunoreactivity for myeloperoxidase was well preserved following fixation in a variety of fixatives, including Zenker's-acetic acid solution (employed for processing bone marrow biopsies), B5 solution, and formalin. Immunohistochemical detection of myeloperoxidase represents a sensitive and highly specific technique for identification of mature and immature myeloid cells in paraffin-embedded tissue.
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PMID:Myeloperoxidase: a specific marker for myeloid cells in paraffin sections. 172 87

Cytogenetic analyses were performed on 12 adult patients with abnormal megakaryoblastic proliferation which was detected by ultrastructural cytochemical study (platelet peroxidase) and platelet-megakaryocytes-specific monoclonal antibodies (TP-80, Plt1, AN51, and KOR-77). The patients consisted of two patients with myelodysplastic syndromes (MDS), three with acute megakaryoblastic leukemia (AMKL), six with megakaryoblastic transformation in Philadelphia-positive chronic myelogenous leukemia (CML-meg-BC), and one case of chronic myeloproliferative disorder (CMPD). Among them, an inversion of the long arm of chromosome 3 [inv(3)(q21q26)] was found in one AMKL patient with a normal platelet count. Chromosome change at band 3q26 was also found in one MDS patient without thrombocythemia. Furthermore, the long arm of chromosome 13, where rearrangements in myelofibrosis are clustered (13q12----q22) was seen in one MDS patient. Trisomoy of chromosome 19 was found in one AMKL patient and three CML-meg-BC patients. These findings indicate that cytogenetic abnormalities involving 3q26, 13q, and trisomy 19 are associated with hematologic neoplasia with megakaryocytic lineage in adult patients, although these abnormalities were not related to the survival of the patients. During the period of this study, two acute myelogenous leukemia patients (AML-M2 and AML-M5b) with chromosome rearrangements at band 3q21 and thrombocythemia were found, indicating that chromosome abnormality at band 3q21 is related to quantitative platelet dysfunction, whereas that at 3q26 is related to hematologic malignancies with a proliferation of megakaryocytic lineage.
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PMID:Cytogenetic findings in adult acute leukemia and myeloproliferative disorders with an involvement of megakaryocyte lineage. 229 63

A Technicon H-1 hematologic analyzer was used to measure the mean leukocyte myeloperoxidase (MPX) in 160 patients seen in a hematology clinic. The normal range was -15 to +10, which included 95% of 300 consecutive hospitalized patients. No abnormalities in the MPX were found in 35 patients with beta-thalassemia minor, 8 with iron deficiency, 14 with myeloproliferative disorders, 17 with autoimmune disorders, and 37 patients with lymphoma in complete remission. On the other hand 36% (10/28) of lymphoma patients with active disease either at diagnosis or relapse had a MPX of greater than 10 compared to only 2.3% (7/300) in hospitalized patients (P less than 0.001). Increased levels of MPX were found primarily in patients with non-Hodgkin's lymphoma (NHL) of intermediate or high grades, or Hodgkin's disease [56% (9/16) compared to only 8.3% (1/12) in those with low grade NHLs, P less than 0.05]. The MPX levels returned to normal after successful treatment. Of the various chemotherapeutic agents used, only hydroxyurea led to a consistent elevation of the MPX. The authors conclude that MPX is commonly increased in patients with lymphoma and in those receiving hydroxyurea. Further studies are required to determine if the MPX is a sensitive test for relapse in patients with lymphomas who had an elevated pretreatment value.
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PMID:The mean leukocyte myeloperoxidase index in hematological patients. 255 19

A case of megakaryoblastic transformation of a myeloproliferative disorder presenting initially as chronic granulocytic leukaemia with an intermediate phase of essential thrombocythaemia in a Chinese woman of 65 years is reported. The diagnosis of megakaryoblastic crisis was based on morphological, cytochemical and immunocytochemical features present in blast cells in the blood, together with cytochemical and ultrastructural features of micromegakaryocytes and megakaryoblasts which were predominant in the marrow. A literature review showed newer refinements in diagnosis such as ultrastructural platelet peroxidase and additional immunologic techniques employing antisera against further platelet products. The response to treatment remains uniformly poor.
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PMID:Megakaryoblastic transformation of a myeloproliferative disorder. 262 27

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

Transient myeloproliferative disorder accompanied by Down's syndrome has been characterized as exhibiting self-limiting haematological abnormalities. We studied six patients suffering from this disorder in order to clarify the biological nature of their blast cells. Metaphases of leucocytes stimulated with phytohaemagglutinin (PHA) showed trisomy 21 in all patients except one. The exception was constitutionally trisomy 21 mosaic (46,XY = 89/47,XY,+21 = 11). However, metaphases from the peripheral blood cells (blast cells: 70%) without PHA stimulation showed exclusively trisomy 21. Simultaneous examination for morphology and chromosomal analysis on single colonies revealed that granulocyte-macrophage (GM) colonies and an erythroid colony contained only cells with the trisomy 21 karyotype. The blast cells showed positive reactions for platelet peroxidase (PPO) and with monoclonal antibodies against platelet-megakaryocyte antigen (TP 80 and TP 82). In methylcellulose and liquid culture systems, high plating efficiencies were observed, and mainly mature basophils containing histamine developed in the presence of PHA-stimulated leucocyte conditioned medium (PHA-LCM). In vivo, mature neutrophils, basophils, eosinophils or megakaryocytes coexisted with PPO-positive blast cells in the peripheral blood of some patients with this disorder. These findings suggest that transient myeloproliferative disorder is characterized by a proliferation of PPO-positive blast cells with trisomy 21, although some heterogeneity may be seen.
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PMID:Platelet peroxidase-positive blast cells in transient myeloproliferative disorder with Down's syndrome. 296 60

A leukaemoid reaction was observed in 3 newborns with Down's syndrome. Thrombocytopenia was present in 2, requiring platelets transfusions in 1, and red cell transfusions were necessary in 2 patients. Blast cells characterization by specific monoclonal antibodies showed a prevalence of megakaryoblasts in all 3 cases. This feature was confirmed in 2 of them by the demonstration of platelet peroxidase (PPO) activity under transmission electron microscopy (TEM). A spontaneous remission of the leukaemoid picture was observed after 2-3 months. However, in 1 case a relapse of the myeloproliferative disorder with the same features of the blast cell population was diagnosed after 16 months. Chemotherapy with low-dose Ara-C, started because of a relevant clinical involvement, induced a complete remission.
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PMID:Leukaemoid reaction with megakaryocytic features in newborns with Down's syndrome. 296 74

Cytogenetic, immunologic, and electron microscopic studies were performed on the blast cells of 28 pediatric patients with Down's syndrome, 13 with acute leukemia (DS-AL) and 15 with transient myeloproliferative disorders (DS-TMD). Clonal chromosome abnormalities were found in the cells of all patients with DS-AL but not those with DS-TMD. The younger ages and higher hemoglobin concentrations, platelet counts, and WBC counts of DS-TMD patients provided a clinical contrast with the frankly leukemic cases. Myelodysplastic syndrome, characterized by a small percentage of leukemic blast cells, was observed in 11 of the 13 patients with DS-AL compared with none in the DS-TMD group. Electron microscopy disclosed a positive platelet peroxidase reaction in each of the 11 DS-TMD patients and in nine of the 13 DS-AL patients. Immunologic studies revealed antiplatelet-megakaryocyte antigens on the blast cells of the majority of patients in both study groups. Our findings suggest that the blast cells in cases of DS-AL and DS-TMD arise from cells of the megakaryocytic lineage or from a myeloid progenitor with the capacity for megakaryocytic differentiation. The high risk of the development of AL in patients with DS who are less than 3 years old may be related to increased megakaryocyte proliferation in this age group.
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PMID:Cytogenetic findings and clinical features in acute leukemia and transient myeloproliferative disorder in Down's syndrome. 296 22


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