Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0023473 (chronic myeloid leukemia)
 18,916 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

An immunohistochemical and morphometric analysis was performed on trephine biopsy specimens of the bone marrow in 40 patients (23 men and 17 women, mean age 62 years) with different subtypes of myelodysplastic syndromes (MDS) to determine dysmegakaryopoiesis, but particularly precursor cells--that is, pro- and megakaryoblasts. In 31 of the 40 patients the numbers of megakaryocytes were increased which was associated with a predominance of smaller cell forms (micromegakaryocytes). Compared with periodic acid Schiff, immunostaining with a formalin resistant monoclonal antibody against glycoprotein IIIa (Y2/51(CD61) showed a clinically important proportion of immature elements. These could be designated pro- and megakaryoblasts by taking morphometric measurements on smears and bone marrow sections. There was a relevant increase in the number of promegakaryoblasts in 32 patients, consistent with uncontrolled expansion of the precursor pool. Seventeen repeated bone marrow biopsy specimens taken after chemotherapy largely showed a decrease in the numbers of megakaryocytes including the precursor cell population. Moreover, morphometric evaluation disclosed that micromegakaryocytes in MDS differ significantly from those in chronic myeloid leukaemia (CML) due to distinctive nuclear features and a disturbed nuclear:cytoplasmic ratio. These changes generate a more pleomorphic or atypical appearance of this cell population in MDS, compared with micromegakaryocytes in CML. It is concluded that the disproportionate increase in megakaryocyte precursors and the grossly abnormal aspects of micromegakaryocytes in MDS are characteristics of the severe defect involving haematopoiesis in this disorder.
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PMID:Dysmegakaryopoiesis in myelodysplastic syndromes (MDS): an immunomorphometric study of bone marrow trephine biopsy specimens. 203 Jan 48

We have analyzed morphological and biochemical changes occurring during megakaryocytic differentiation of the human chronic myelogenous leukemia cell line K562 induced by phorbol 12-myristate 13-acetate (PMA). PMA-treated cells became growth arrested, were slightly larger and irregular in shape, adhered better to the culture flask surface, and expressed the glycoprotein IIIa on their surfaces. The morphological changes induced by PMA treatment were associated with the disappearance of actin from the cytosol and presumably reflect PMA-induced actin polymerization. Megakaryocytic differentiation was accompanied by about a 3-fold decrease in the specific phosphotyrosine protein phosphatase (PTPase) activity in the particulate membrane fraction, whereas the activity in the soluble cytosol fraction increased about 3-fold. The decrease of PTPase activity in the particulate membrane fraction could be attributed to the disappearance of at least 1 distinct PTPase form displaying an apparent native Mr of 200,000 and a reduction in activity of a Mr 43,000 PTPase found associated with membranes of all cells examined to date. The increase of PTPase activity in the cytosol fraction manifested itself by the appearance of a new Mr 40,000 PTPase and a reduction of a Mr 60,000 PTPase. These results suggest the existence of several growth- and/or differentiation-related PTPase activities in K562 cells.
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PMID:Megakaryocytic differentiation of K562 cells is associated with changes in the cytoskeletal organization and the pattern of chromatographically distinct forms of phosphotyrosyl-specific protein phosphatases. 216 44

A morphometric study was performed on trephine biopsies of bone marrow in patients with chronic myeloid leukemia (CML) accompanied by myelofibrosis and in so-called primary (idiopathic) osteomyelofibrosis/-sclerosis (OMF) to evaluate distinctive features of megakaryopoiesis. The periodic acid Schiff reaction (PAS) and a monoclonal antibody against glycoprotein IIIa were employed for the identification of megakaryocytes including precursor cells and Gomori's silver impregnation to determine the density of argyrophilic fibers. All patients with CML revealed a slight to moderate degree of medullary fibrosis and were compared with early hyperplastic stages of OMF showing an identical fiber count. Statistical analysis disclosed that distinctive features existed between these two subgroups. Amongst these variables were sizes of megakaryocytes and corresponding nuclei, frequency of bare nuclei, emperipolesis and numbers of isolated nuclear fragments as well as the circular deviation of cell and nuclear perimeters. Immunomorphometry also included immature elements (pro- and megakaryoblasts) of the megakaryocyte series. Consequently higher cell counts were calculable in both groups combined with smaller sizes and a more rounded aspect of nuclei. However, following immunostaining, significant differences in several megakaryocytic parameters (frequency, size, shape of nuclei) were still demonstrable between CML and OMF cases.
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PMID:Histo- and immunomorphometry of megakaryopoiesis in chronic myeloid leukemia with myelofibrosis and so-called primary (idiopathic) osteo-myelofibrosis/-sclerosis. 227 69

Carbohydrate-specific surface labelling and 125I-labelled lectin binding techniques, in combination with one- or two-dimensional (non-reduced/reduced) SDS-polyacrylamide gel electrophoresis have been used with platelets from patients with myeloproliferation disorders and secondary thrombocytosis and from healthy donors. In essential thrombocythaemia platelet membrane glycoproteins were significantly less sialylated than in normals (particularly GP Ib and IIIa). Increased binding of 125I-labelled Lens culinaris lectin to thrombospondin and GP IIIa indicated a defect in the glucose/mannose glycosylation of the platelet glycoproteins in essential thrombocythaemia. In polycythaemia vera and in chronic myeloid leukaemia the terminal sialic acid of glycoprotein IIIb was labelled slightly more than normal. In chronic myeloid leukaemia there was increased labelling of the penultimate galactose/N-acetylgalactosamine residues of GP Ib, IIb, IIIa and IIIb. In comparison to myeloproliferative disorders, platelets from patients with secondary thrombocytosis showed no significant changes, except for platelets from two patients with idiopathic thrombocytopenic purpura which showed an increased sialylation of all surface glycoproteins.
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PMID:Platelet membrane glycoprotein abnormalities in patients with myeloproliferative disorders and secondary thrombocytosis. 400 82

Megakaryocyte (MK) ploidy patterns were analysed by flow cytometry in 29 newly diagnosed and previously untreated patients with chronic myeloproliferative disorders (MPD) and concomitant thrombocytosis, in 9 patients with reactive thrombocytosis (RT) and in 12 healthy individuals. Unfractionated bone marrow from routine aspirates was used. MKs were identified with a fluorescein labelled monoclonal antibody specific for glycoprotein IIIa (GPIIIa) and DNA was stained with propidium iodide. For the 12 healthy volunteers the mean modal ploidy number was 16 N; the 9 patients with RT displayed an identical MK ploidy pattern. The frequency of MKs with a ploidy > or = 32 N was 45% among the patients with essential thrombocythaemia (ET) compared to 32% among the healthy volunteers (p < 0.001). MKs with ploidy number > or = 64 N, comprising approximately 13% of the total number of MKs, was a characteristic finding in the patients with ET. Similar findings were present in 8 patients with polycythaemia vera (PV). In patients with PV 34% and 6% of the MKs displayed ploidies > or = 32 N and > or = 64 N, respectively. In contrast, a distinct shift towards lower ploidy number, with 63% of MKs < or = 8 N, was found among the 4 patients with chronic myeloid leukaemia (CML). The present results indicate that by using flow cytometric analysis of MK ploidy distribution in patients with thrombocytosis, those with a reactive cause are likely to be discriminated from patients with myeloproliferative thrombocytosis, i.e. PV and ET on one hand and CML on the other hand. The distinction between ET and PV, however, has to be made on other grounds.
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PMID:Flow cytometric analysis of megakaryocyte ploidy in chronic myeloproliferative disorders and reactive thrombocytosis. 864 2

A flow cytofluorometric measurement of megakaryocyte ploidy has been adapted from Tomer's method. Briefly, bone marrow is aspirated through a medium containing theophyllin, prostaglandin-E1 and other antiaggregant agents. Megakaryocytes-enriched buffy coats are recovered. Megakaryocytes are then stained for GP IIIa coupled with FITC and for DNA (propidium iodide). A Becton Dickinson FACScan flow cytometer is used for measuring the ploidy distribution of GP IIIa positive cells. The method we developed presents several advantages. Firstly, the time required is greatly decreased in comparison with other studies. Secondly, the washing steps are limited in number allowing a diminution of the cell loss. Thirdly, the method ensures a better megakaryocyte preservation. Finally, selection of megakaryocytes by ploidy and expression of GP IIIa can be made easily because of the simultaneity of the two stainings as well as by the use of a precise gating on the flow cytometer. Based on these results, we conclude that the present method provides a better means for the isolation and analysis of human normal megakaryocytes. This technique has been applied to the analysis of megakaryocyte populations from patients with abnormal platelet counts. In chronic myeloid leukemia patients, analysis of ploidy distribution shows a shift toward the low ploidy while in patients with immune thrombocytopenic purpura, polycythemia vera and essential thrombocythemia the ploidy distributions are shifted toward the high ploidy.
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PMID:Analysis of megakaryocytes by flow cytometry. 1006 47