Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound   Target Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound

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Query: EC:1.11.1.7 (peroxidase)
65,474 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

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CLL, HCL, Hodgkin's disease, anaemia not related to leukaemia and leukaemoid reactions the incidences all were 0% (I, unpublished data).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

Among AML with maturation, acute promyelocytic leukemia (APL) represents a distinct subtype which accounts for 5-10% of all the FAB variants. APL may be recognized by different cytological pictures: (i) Hypergranular APL, the most typical form, showing promyelocytes with cytoplasm packed with purple granules. Most of the primary granules may be incorporated into Auer rods, sometimes stacked in bundles of faggots. (ii) Microgranular APL, characterized by fine dust-like granulation in the cytoplasm; some promyelocytes may even appear agranular by light microscopy. Most of the cells show bilobed or folded nuclei, a picture which may simulate that of acute myelomonocytic leukemia. (iii) Hyperbasophilic form, characterized by cells with high N/C ratio, and strongly basophilic cytoplasm with either sparse or no granules. Conspicuous cytoplasmatic budding is usually present, recalling the feature of micromegakaryocytes. Strong positivity for myeloperoxidase, Sudan black B and chloroacetate esterase represents the typical cytochemical pattern of M3; usually a weaker reactivity may be observed in M3v. However, sometimes a degree of cytochemical heterogeneity of APL cells may be observed, as suggested by cases displaying a strong sodium fluoride-sensitive nonspecific esterase reaction. Recently a distinct entity associated with basophilic differentiation has been described. Differential diagnosis of this form with M2-baso subtype and with cases of MDS or AML with basophilia (M2, M4 with t(6;9) translocation) may be obtained by the use of cytochemistry, cytogenetic investigations, and electron microscopy.
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PMID:Acute promyelocytic leukemia: morphological aspects. 781 33

f-Met-Leu-Phe-stimulated luminol-enhanced chemiluminescence was found to be repeatedly defective in some MDS patients. This defect was not attributed to myeloperoxidase deficiency, nor to a defect in NADPH oxidase function, because PMA chemiluminescence was found to be normal in these individuals. An arbitrary value of 7 mV (half the mean control value) was chosen to subdivide the group: MDS patients with values < 7 mV had a mean f-Met-Leu-Phe chemiluminescence response of 2.5 +/- 0.5 compared to MDS patients with values > 7 mV who had a mean response of 15.6 +/- 1.6 mV, P < 0.01 (healthy controls 14 +/- 2 mV). The characteristics of the f-Met-Leu-Phe receptor and initial calcium flux results suggested that the receptor itself was normal in number and function in low f-Met-Leu-Phe responders. The rate of superoxide generation, which is calcium-dependent, was also found to be in the normal range in low f-Met-Leu-Phe responders, although total superoxide production was reduced in some of these patients. When MDS neutrophils with a low f-Met-Leu-Phe response were stimulated with PMA, chemiluminescence was normal, suggesting normal activity of the NADPH-oxidase complex. Furthermore, myeloperoxidase activity was reduced in only three out of the 11 low f-Met-Leu-Phe responders. Following priming with GM-CSF, f-Met-Leu-Phe chemiluminescence was 27 +/- 1.6 mV in low f-Met-Leu-Phe responders compared to controls (87.7 +/- 11 mV, P < 0.005). Thus, although responses were improved, they were not as marked as in control neutrophils. These data suggest that a subgroup of MDS patients have a low f-Met-Leu-Phe chemiluminescence response which is not due to a defect in the f-Met-Leu-Phe receptor or oxidase activity, and in the majority of cases MPO activity is normal. Initial patient survival data suggest that these patients may have an increased risk of infective mortality. It is proposed that defective f-Met-Leu-Phe chemiluminescence results from a putative defect in cell-signalling mechanism upstream of PKC, and GM-CSF priming only partially improves responsiveness.
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PMID:Identification of a subgroup of myelodysplastic patients with a neutrophil stimulation-signalling defect. 791 69

Among AML with maturation, acute promyelocytic leukemia (APL) represents a distinct subtype which accounts for 5-10% of all the FAB variants. APL may be recognized by different cytological pictures: (i) Hypergranular APL, the most typical form, showing promyelocytes with cytoplasm packed with purple granules. Most of the primary granules may be incorporated into Auer rods, sometimes stacked in bundles of faggots. (ii) Microgranular APL, characterized by fine dustlike granulation in the cytoplasm; some promyelocytes may even appear agranular by light microscopy. Most of the cells show bilobed or folded nuclei, a picture which may simulate that of acute myelomonocytic leukemia. (iii) Hyperbasophilic form, characterized by cells with high N/C ratio, and strongly basophilic cytoplasm with either sparse or no granules. Conspicuous cytoplasmatic budding is usually present, recalling the feature of micromegakaryocytes. Strong positivity for myeloperoxidase, Sudan black B and chloroacetate esterase represents the typical cytochemical pattern of M3; usually a weaker reactivity may be observed in M3v. However, sometimes a degree of cytochemical heterogeneity of APL cells may be observed, as suggested by cases displaying a strong sodium fluoride-sensitive non-specific esterase reaction. Recently a distinct entity associated with basophilic differentiation has been described. Differential diagnosis of this form with M2-baso subtype and with cases of MDS or AML with basophilia (M2, M4 with t(6;9) translocation) may be obtained by the use of cytochemistry, cytogenetic investigations, and electron microscopy.
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PMID:Acute promyelocytic leukemia: morphological aspects. 809 23

We treated a 16-month-old girl with myelodysplastic syndrome (MDS; refractory anemia with excess of blasts subtype, RAEB by FAB classification) that developed into acute megakaryoblastic leukemia (ANLL-M7). The blast cells were positive for CD41 shown by flow cytometry and for platelet peroxidase by electron microscopy. Cytogenetically, five kinds of abnormal karyotypes were apparent at the initial visit and karyotypic progression (clonal evolution) was also evident. These karyotypes were considered to be derived from the putative original clone, 48,XX, +6, +21. The observed karyotypes were considered 50,XX, +4,add(4)(q31), +6,add(7)(p22),add(10)(q24),add(12)(q11), +20, +21, + mar[karyotype A];48,XX,add(4)(q31), +6,add(10)(q24),add(12)(q11), +21 [karyotype B];48,XX, +6,t(6;13)(p23;q14), +21 [karyotype C];51,XX, +X, t(6;13)(p23;q14), + der(6)t(6;13)(p23;q14), +21, +21, + mar [karyotype D]; and 49,XX, +X, -3,t(6;13)(p23;q14), +der(6)t(6;13)(p23;q14), -12, +21, +21, + mar [karyotype E]. It seems karyotypes B and C were derived from the putative clone; karyotype B developed into karyotype A; and karyotype C developed into karyotype E through karyotype D. After development of ANLL-M7, the cytogenetic study showed a karyotype with further karyotypic progression. The patient was treated with high-dose cytosine arabinoside (HD AraC) followed by allogeneic bone marrow transplantation. Despite intensive care, she died 3 months after the transplantation.
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PMID:Childhood myelodysplastic syndrome with clonal evolution progressing to acute megakaryoblastic leukemia (ANLL-M7). 822 7

When purified control neutrophils were primed with GM-CSF, a significant increase in FMLP-induced MPO release was observed (mean +/- S.E.M., 3.4 +/- 0.8 mU/10(7) unprimed cells compared to 6.5 +/- 1.1 mU/10(7) primed cells, p < 0.001). This MPO release was greatly augmented by Cytochalasin B (Cy B), but after the addition of Cy B the priming effects of GM-CSF became less obvious. Exposure to GM-CSF without FMLP did not enhance MPO release. Within whole blood, FMLP produced negligible MPO release, but priming with GM-CSF prior to FMLP always resulted in a significant increase in MPO release. Myelodysplastic neutrophils released similar amounts of MPO in response to FMLP, compared with control cells (3.4 +/- 0.8 mU/10(7) control cells compared to 2.7 +/- 0.3 mU/10(7) MDS cells, p > 0.05). Priming with GM-CSF produced an increase in FMLP-stimulated MPO release comparable with control cells. In terms of total MPO content, although some MDS patients exhibited low levels, as a group there was no significant difference from controls (169 +/- 21 mU/10(7) control cells compared with 157 +/- 19 mU/10(7) MDS cells). These findings suggest that MPO activity is not a universal defect in MDS and cannot account for the defects in respiratory burst activity in these neutrophils.
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PMID:The effects of GM-CSF on myeloperoxidase release in normal and myelodysplastic neutrophils. 824 7

A 78 year old female was found to have pancytopenia in February 1991. Bone marrow was normocellular with 11.7% blasts and showed dysmegakaryopoietic changes. A diagnosis of MDS (RAEB) was made and she was treated with transfusions and ubenimex. Leukemic transformation was noted in July. On Admission in October 1991, her laboratory examinations revealed the following: WBC 38,900/microliters with 93% blast, Hb 8.0 g/dl, Plt 2.1 x 10(4)/microliters, a hypercellular bone marrow with 74% blasts which were negative for myeloperoxidase (MPO) by light microscopy, but were positive by electron microscopy. Surface marker for CD13 was positive. These findings corresponded to M0 of the FAB subtype. Chromosome analysis revealed Ph1 chromosome with 46XX, t (9;22) (q34;q11) in 3 of 3 cells examined, Southern analysis showed the rearrangement of the break point cluster region (bcr). Reverse transcriptase polymerase chain reaction technique demonstrated the presence of major bcr/abl mRNA. She was treated with transfusions and methyl-prednisolone. Her blast counts declined and Ph1 chromosome was only positive in 1 of 12 metaphases examined. She died of pneumonia in December 1991. Eleven cases with MDS showing Ph1 chromosome have previously been reported. The observations indicate that Ph1 chromosome positive acute leukemias were heterogenous in nature.
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PMID:[RAEB transformed into AML (M0) showing Ph1 chromosome and rearrangement of major cluster region]. 825 8

FAB proposals for the diagnosis of AML-M0 represent the formal recognition of a distinct entity which has been described over the past few years by several authors and called minimally differentiated acute myeloid leukemia. By definition, AML-M0 includes acute leukemias which do not fit morphological and cytochemical criteria for the diagnosis of AML, and for which myeloid lineage assignment can be made by immunological assay showing positivity for MPO, CD13, and CD33 and negativity for lymphoid markers. Involvement of an early myeloid progenitor in the leukemic process is a possible theory hypothesized to explain the existence of such a form. Validity of this assumption has been based on the observation that AML-M0 frequently bears "stem cell" markers such as CD34, HLA-DR, Tdt, CD7, and promiscuous IgH/TCR gene rearrangements, which are thought to occur in uncommitted cells. Finally, AML-M0 very frequently carries cytogenetic abnormalities common to MDS or secondary AML, such as -5/5q- or -7/7q- deletions and or complex karyotype. In our experience, AML-M0 is also very often associated with the MDR phenotype, which in turn has been found strictly linked to "stem cell" features, especially in MDS. These biological aspects, altogether, translate into a very unfavorable prognosis, confirming even from a clinical point of view that AML-M0 is a distinct entity. In conclusion, "stem cell" markers, MDR phenotype, complex chromosome lesions, frequent occurrence in elderly patients, and intrinsic chemoresistance characterize AML-M0 and indicate the need for tailored treatments, possibly involving the use of MDR modulators and/or differentiating agents.
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PMID:Minimally differentiated acute myeloid leukemia (AML-M0): a distinct clinico-biologic entity with poor prognosis. 862 74

We studied 22 patients with hematological neoplasias which included: 12 patients with a diagnosis of Acute Myeloblastic Leukemia (AML) following the morphology and cytochemistry criteria established by FAB (French, American and British Committee), a Myeloblastic Leukemia secondary to MDS (Myelodysplastic Syndromes) and a biphenotypic acute leukemia where we established the relationship between the traditional peroxidase reaction with the anti-MPO by APAAP. We also carried out the nonspecific esterase reaction and determined the immunologic phenotype by FACS technology. The same procedure was used for the cellular analysis of the light chains kappa (kappa) and lambda (lambda) in 3 cases of hairy cell leukemia, one lymphoma and 4 cases of plasma cell neoplasia and reactive plasma cell disease. We conclude that immunocytochemical reactions must be used when morphology and traditional cytochemical reactions need to be confirmed in order to establish a correct diagnosis and this is specially important for B and T lymphomas. Their prognostic value is restricted and the results are useful as a complement to morphology, cytochemistry and immunological determinations.
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PMID:[Immunocytochemistry techniques for the diagnosis of hematologic neoplasms]. 1034 12

We evaluated 443 outpatients and inpatients in Keio University Hospital between 1994 and 1999. Morphologic features from peripheral blood and bone marrow aspiration were evaluated in our hematology laboratory, using Wright-Giemsa, peroxidase staining films and other cytochemistry. Immunophenotype was determined by cell surface antigen analysis by laser flow cytometry, FACscan, using various monoclonal antibodies. Information on cytogenetic and molecular genetic characteristics can be also integrated for diagnosis. One hundred fifty patients were diagnosed with acute leukemia, in which 59 cases were ALL and 91 cases were AML. Seventy-four cases were MDS, 76 cases were myeloproliferative disorders, 21 cases were CLL related disorders, 104 patients were malignant lymphoma, and 18 cases were multiple myeloma. The ratio of male to female was 1.7. The probability of diagnostic rate by Immunophenotyping was estimated by Discriminant analysis in 189 patients, using multivariate analysis of immunophenotype compared to morphology. The average probability by immunophenotypic analysis for diagnostic rate was 91.7%, in which the probability for NHL was very high of 97.1%. Thus, morphologic and immunophenotypic analysis is most essential and basic approach in laboratory hematology, from the perspective of rapid and precise diagnostic methods. Recent advance appreciates the rapid contribution for diagnosis by immunophenotypic analysis. Furthermore, Tele-hematology would contribute the standardization for morphologic method in the near future.
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PMID:[Morphology and immunophenotyping in hematological malignancies]. 1106 91


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