Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0023418 (leukemia)
 93,477 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

In general, megakaryocytic myelosis is nowadays considered to be a separate disease entity, one of the myeloproliferative syndromes. Morphologically there are localised or diffuse proliferations of usually large pleomorphic megakaryocytes and immature atypical megakaryocytes up to megakaryoblasts in the bone marrow, in the sense of a haemoblastosis. In the course of the disease megakaryocytic splenomegaly develops. A sarcomatous form (megakaryoblastoma, megakaryo-sarcoma) is rare. Megakaryocytic myelosis may arise from chronic meyloid leukaemia or polycythaemia vera, rarely as a transitional stage to an acute myeloblastic leukaemia or megakaryoblastic leukemia in the sense of a blast crisis. The mature form of the disease, which has an age peak at 59 years and is not sex-linked, often takes a course over years with increasing splenomegaly, anaemia, moderate leucocytosis and usually marked thrombocytosis (average value of 720 X 10(9)/1). Life threatening complications are haemorrhages, thromboembolism and increased frequency of infections due to antibody deficiency in the advanced stage.
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PMID:[Megakaryocytic myelosis: clinical and morphological features (author's transl)]. 26 86

A 63-year-old man was admitted because of anemia and thrombocytopenia. The bone marrow was hypercellular with 66.6% erythroblasts with dysplasia and 19.8% blasts. Cytogenetically, MAKA (major karyotypic aberrations) containing 5q-, -7, -17, with karyotypic instability was observed. A diagnosis of erythroleukemia (FAB M6) was made. Six months later, immature neutrophils increased in the peripheral blood, and blasts and promyelocytes increased to 25.8% and 20.0% of marrow cells, respectively. Three months later, blasts asts increased to 33.0% in the peripheral blood. They were ultrastructually positive for platelet peroxidase. Phenotypically, 69% and 63% of blasts were positive for CD41b (GPIIb/IIIa) and CD42a (GPIb), respectively. Bone marrow biopsy showed marked proliferation of blasts and dysplastic megakaryocytes accompanied by reticulin fibrosis. These findings suggested evolution to megakaryoblastic leukemia (FAB M7). In most cases, M6 defined by the FAB criteria is stem cell disorder with multilineage involvement and major erythroid component. M6-like features may be observed in the evolutive phase to acute leukemia from myelodysplastic syndrome (MDS).
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PMID:[Evolution to megakaryoblastic leukemia observed in myelodysplastic syndrome with erythrolekemia-like features]. 140 64

Clinical, morphological, immunological, cytogenetical and prognostic features of 84 children under 2 years of age with AML in studies AML-BFM-78, -83 and -87 were retrospectively analysed. There was a high incidence of acute monoblastic leukaemia (FAB M5) (41 patients--49%) and acute megakaryoblastic leukaemia (FAB M7) (study AML-BFM-87: five patients--13%) in this age group. Acute monoblastic leukaemia was associated with hepatosplenomegaly, extramedullary organ manifestations and chromosomal abnormalities involving 11q23. The probability of an 11-year event-free survival of all patients under 2 years of the three studies combined was 39% (SD 6%). While the event-free survival rates of patients aged 2 years and older could be improved in studies AML-BFM-83 and -87 compared with study AML-BFM-78, overall prognosis in children under 2 years in the three consecutive studies remained unchanged. The event-free survival rate of children with acute monoblastic leukaemia in both age groups was comparable (7 yr-EFS (AML-BFM-83 and -87): much less than 2 years--43% (SD 9%), =/much greater than 2 years--33% (SD 9%); P much greater than 0.5). This also applied to other risk groups. In conclusion, taking the high incidence of acute monoblastic and megakaryoblastic leukaemia in children under 2 years into account, no significant differences between children under 2 years or older children concerning response to therapy and overall prognosis could be evaluated.
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PMID:Acute myelogenous leukaemia in children under 2 years--experiences of the West German AML studies BFM-78, -83 and -87. AML-BFM Study Group. 150 29

smg p21A and -B (smg p21s) are ras p21-like small GTP-binding proteins (G proteins) with the same putative effector domain as ras p21s. Both smg p21A mRNA and smg p21B mRNA were detected in CMK, a human megakaryocytic leukemia cell line, and their levels were markedly elevated by treatment with 12-O-tetradecanoyl-phorbol-13-acetate (TPA), which caused the differentiation of this cell line into more mature megakaryocytes. The smg p21 protein molecules also increased during the TPA-induced differentiation of CMK cells. The mRNA level of glycoprotein IIb (GPIIb), a typical marker of the megakaryocytes, was increased by this treatment, but the time course of the increase in the smg p21 mRNA levels as more rapid than that of the increase in the GPIIb mRNA level. Ha-ras p21 mRNA was undetectable, but both Ki- and N-ras p21 mRNAs were detected in CMK cells and their levels were also increased during TPA-induced differentiation of CMK cells, although to a lesser extent than those of smg p21 mRNAs. Protein kinase C inhibitors inhibited the basal and TPA-induced smg p21A mRNA level, but cyclic AMP-elevating prostaglandin E1 or Ca(2+)-mobilizing ionomycin did not inhibit them. Cycloheximide enhanced the basal and TPA-induced smg p21A mRNA levels. Actinomycin D blocked the TPA-induced smg p21A mRNA levels, but showed no detectable effect on the elevated smg p21A mRNA level which was induced by pretreatment with TPA. A dramatic increase in the smg p21 mRNA levels was also observed in other leukemia cell lines during TPA-induced differentiation. These results suggest that TPA stimulated expression of the smg p21A gene, presumably through the action of protein kinase C at the transcriptional level rather than at the post-transcriptional level, in hematopoietic leukemia cells.
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PMID:Induction of smg p21/rap1A p21/krev-1 p21 gene expression during phorbol ester-induced differentiation of a human megakaryocytic leukemia cell line. 154 53

We present the nonrandom occurrence, frequency, and degree of immunophenotype association of the t(1;22)(p13;q13) in children with acute nonlymphocytic leukemia (ANLL). This karyotype anomaly occurred in leukemia cells from five of 445 (1.1%) children with newly diagnosed ANLL who were successfully studied by cytogenetic analysis at four European centers between January 1987 and January 1992. The occurrence of the t(1;22) was restricted to the French-American-British classification (FAB) subtype M7. The overall incidence in children with acute megakaryocytic leukemia (AMKL) was 27.8% (5/18 cases); in infants with AMKL, the frequency of the t(1;22) was 66.7% (4/6 cases). Three of the patients carrying this anomaly had a diploid karyotype, whereas in two cases a hyperdiploid karyotype was found. However, in all five patients, the t(1;22) was the only translocation event present at diagnosis. All patients received aggressive chemotherapy for acute myelogenous leukemia (AML). Two patients died within 15 months of diagnosis without entering remission. One of three patients who entered remission died 7 months after diagnosis, most likely from intramedullar hemorrhage. Only two of the five children with the t(1;22) who received autologous bone marrow transplantation (BMT) are alive and in complete remission (CR) 23 and 40 months after diagnosis, respectively. At the time of diagnosis, the age of the oldest child carrying the t(1;22) was 18 months. The cases with this chromosome anomaly were compared with an age-matched group of five children with AMKL lacking this translocation. The patients with the t(1;22) had a lower median value of the peripheral white blood cell (WBC) count and a higher median hemoglobin level than the patients from the matched group. In the latter cases, normocellular or hypercellular bone marrow (BM) was detected at diagnosis. In contrast, all children with the t(1;22) in our series had a hypocellular BM. Histological BM analyses were available in three of these patients and showed marked fibrosis. Other clinical and laboratory parameters showed no obvious differences between the matched groups. Despite intensive chemotherapy, AMKL in children appears to be associated with a poor prognosis. The clinical courses of the children with AMKL and the t(1;22) presented may be indicative of a beneficial effect of autologous BMT in this subset of patients.
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PMID:The translocation t(1;22)(p13;q13) is a nonrandom marker specifically associated with acute megakaryocytic leukemia in young children. 159 73

Acute megakaryoblastic leukemia has emerged as an important subset of early childhood leukemia. It often presents a diagnostic dilemma because of its many morphologic manifestations and propensity to mimic metastatic carcinoma. An abdominal mass was identified by sonographic and computed tomographic scans in a 10-month-old girl, who had anemia and thrombocytopenia. An open biopsy of the 3-cm, peripancreatic mass showed cohesive nests and sheets of tumor cells with focal spindling and desmoplasia. Although the diagnosis of acute megakaryoblastic leukemia was established from a bone marrow aspirate using immunocytochemical techniques and karyotype analysis, a coexistent abdominal epithelial malignant neoplasm could not be excluded entirely by light microscopic examination alone. The megakaryoblastic nature of the abdominal tumor was established by immunocytochemical stains for glycoprotein IIIa on paraffin-embedded tissue.
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PMID:Acute megakaryoblastic leukemia simulating carcinoma. 161 27

Peripheral blood leukemic cells from four patients with peroxidase negative acute leukemia, which expressed neither myeloid nor lymphoid cell surface antigens, were analyzed by using monoclonal antibodies (MoAb) capable of recognizing megakaryocyte-platelet-related antigens. Leukemic cells from one case reacted with 5F1 MoAb, whereas cells from all the tested cases reacted with OKM5 MoAb, which belongs to the same CD group as 5F1 (CD36). Also, culture cells from megakaryoblastic leukemia cell line, MEG-01, and human erythroleukemia cell line, HEL, showed a different pattern of expression for the CD36 antigen molecule detected by 5F1 and OKM5 MoAb, individually. Furthermore, we have demonstrated that the epitopes recognized by 5F1 and OKM5 MoAb appear on the same CD36 molecule on the surface of HEL cells by means of the two-color analysis using FACS-IV. On the basis of our experiments, we conclude that, CD36 molecule, a receptor for TSP, is synthesized and expressed in at least two ways, inside the cells and on the surface of megakaryocyte lineage leukemias and megakaryocytic leukemia cell lines MEG-01 and HEL. This is strongly suggestive that thrombospondin (TSP)-mediated adhesion represents an alternative pathway for cytoadherence, and that CD36 expression on various kinds of cells may lack some essential modifications or components necessary for the TSP receptor activity.
Leukemia 1990 Jul
PMID:Different expression of CD36 antigen molecule on the surface of megakaryocyte lineage leukemias and megakaryocyte leukemia cell lines MEG-01 and HEL. 169 6

An unusual presentation of acute megakaryocytic leukemia (AMKL) is reported in two young children. The first child had a 10-day history of ptosis of the right eyelid as the initial manifestation of AMKL, a clinical picture not previously described in this variant of leukemia. Computed tomographic scanning showed multiple intracranial mass lesions, and the diagnosis of AMKL was confirmed by immunophenotyping of bone marrow blasts. The second child had Down syndrome and received alkylating agents and radiation therapy for treatment of metastatic rhabdomyosarcoma of the orbit. She had AMKL as second malignancy. Both patients had acquired chromosome 21 anomalies in their leukemic blasts. The first patient, constitutionally normal, had an i(21q) in his leukemic blasts; the patient with constitutional trisomy 21 had tetrasomy 21 and additional chromosomal changes. The clinical symptoms and the results of morphologic, immunologic, and cytogenetic studies are discussed.
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PMID:Acute megakaryocytic leukemia in children. Clinical, immunologic, and cytogenetic findings in two patients. 183 41

A case of acute megakaryocytic leukemia (M7) and one of acute myeloid hemopathy affecting megakaryocytic and erythrocytic cell lineages in infants are reported. Both patients had t(1;22)(p12-p13;q13). This translocation was previously observed in a congenital M7 leukemia. These studies suggest that t(1;22) translocation can be nonrandom in M7.
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PMID:Nonrandom t(1;22)(p12-p13;q13) in acute megakaryocytic malignant proliferation. 188 57

Acute myeloid leukemia (AML) is characterized by trilineage dysplasia, including atypical megakaryocytes. Acute megakaryoblastic leukemia (FAB M7) is particularly associated with atypical megakaryocytic hyperplasia (AMH). Fifteen patients with nonmegakaryoblastic AML developed AMH after therapy, comprising 12.6% of cases of AML diagnosed from 1986 to 1989. Platelet counts were normal in nine patients and decreased in six. Blasts comprised less than 5% of cells in 40% of the biopsies, ranged from 5-15% in 53%, and comprised more than 30% of cells in 7%. Numerous small hypo- and hyperlobated megakaryocytes were seen in all specimens, often occurring in clusters, and were more easily seen in sections than in smears. Subsequent biopsies in 13 patients showed a remission marrow in seven, increased blasts in three, and AML in three; none showed AMH. AMH resembling acute megakaryoblastic leukemia may be seen transiently after treatment of AML.
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PMID:Dysmegakaryopoiesis resembling acute megakaryoblastic leukemia in treated acute myeloid leukemia. 201 82


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