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Query: UMLS:C0026986 (myelodysplastic syndrome)
 14,926 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

We report on investigations aimed at detecting mutated RAS genes in a variety of preleukemic disorders and leukemias of myeloid origin. DNA transfection analyses (tumorigenicity assay) and hybridization to mutation-specific oligonucleotide probes established NRAS mutations in codon 12 or 61 of 4/9 acute myelocytic leukemias (AML) and three AML lines. Leukemic cells of another AML patient showed HRAS gene activation. By using a rapid and sensitive dot-blot screening procedure based on the combination of in vitro amplification of RAS-specific sequences and oligonucleotide hybridization we additionally screened 15 myelodysplastic syndromes, 26 Philadelphia chromosome-positive chronic myelocytic leukemias in chronic or acute phase, and 19 other chronic myeloproliferative disorders. A mutation within NRAS codon 12 could thus be demonstrated in a patient with idiopathic myelofibrosis and in another with chronic myelomonocytic leukemia. Moreover, mutated NRAS sequences were detected in lymphocytes, in granulocytes, as well as in monocytes/macrophages of the latter case.
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PMID:RAS gene mutations in acute and chronic myelocytic leukemias, chronic myeloproliferative disorders, and myelodysplastic syndromes. 312 17

We treated 11 patients who had Philadelphia-chromosome-positive chronic myelogenous leukemia with natural interferon alpha (human lymphoblastoid interferon; HLBI). HLBI was given at 6-12 X 10(6) u/day i.m. or i.s.c. during induction therapy. Nine patients responded to the treatment, of whom 7 had hematologic remission and 2 had partial remission. Six patients with MDS or hypoplastic leukemia, and 3 patients with overt leukemia from MDS were treated with recombinant interferon gamma (GI-3). GI-3 was given at 0.4 X 10(6) u/m2 of body-surface area per day i.s.c. or i.v. for 4-6 weeks. In 2 patients with RAEB and hypoplastic leukemia, the blast cell count in bone marrow decreased from 8-16% to 2-3% after 4 weeks of administration. In another patient with hypoplastic leukemia, blast cells in the marrow did not decrease, but anemia was improved without transfusion, increasing the bone marrow NCC and erythroblast count. In patients with overt leukemia and CMML, no clinical effect was obtained. Interferons can therefore be offered to patients in a preleukemic state.
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PMID:[Clinical investigation of interferons in the preleukemic state (CML and MDS)]. 313 93

Two male patients with myelodysplastic syndromes, one with refractory anemia with excess blasts (RAEB), the other with chronic myelomonocytic leukemia both had in their bone marrow and peripheral blood cells the same abnormal karyotype 46,X,-Y, + der (Y)t(Y;1)(q12;q21). This abnormality produced trisomy for the 1q21-1qter region of chromosome 1. In addition to the t(Y;1), the patient with RAEB had a del(20)(q11) abnormality in separate CFU-GM and BFUe progenitor cell populations. The t(Y;1) clone of this patient underwent chromosomal evolution with the acquisition of trisomies for chromosomes 2, 6, 8, and 9. Cytogenetic analysis of serial peripheral blood samples showed that the t(Y;1) clone and its derivatives gradually replaced that with the 20q- abnormality. Metaphase cells trisomic for chromosomes 2, 6, 8, and 9 were found predominantly in the CFU-GM population and only rarely in BFUe colonies, suggesting that chromosomal evolution was largely confined to the granulocytic lineage.
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PMID:An identical t(Y;1)(q12;q21) in two patients with myelodysplastic syndromes. 316 4

Members of the RAS gene family have been implicated in many neoplasms with activating mutations around amino acid positions 12 and 61. We have assessed the mutational activation of H, K, and NRAS in myelodysplasia (MDS) by polymerase chain reaction and hybridization with synthetic oligonucleotide probes. Using this method, point mutations in codons 12/13 and 61 of these RAS genes were detected in 20 of 50 patients including two with refractory anemia with ringed sideroblasts (RARS). Ten normal individuals had no detectable RAS mutations. In 11 instances, DNA from patients with detectable RAS mutations were shown to register in either NIH3T3 focus-forming or nude mouse tumorigenicity assays. In addition, one patient (RARS) was shown to have an activated NRAS gene detected by a tumorigenicity assay and Southern blot analyses. Two MDS patients had mutations detected in two different RAS genes. DNA from one of these patients was observed to give rise to transformants with activated N and HRAS. Two patients with detectable NRAS mutations in the MDS stage progressed to AML and DNA from the AML stage registered positively in a transformation assay with NRAS activation. These results show that RAS mutations can occur at early, as well as late, stages of leukemic progression. The incidence of RAS mutations appears to be significantly higher in CMML than in the other subgroups (p = 0.02).
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PMID:RAS mutations in myelodysplasia detected by amplification, oligonucleotide hybridization, and transformation. 316 76

Retrospective analysis of 23 cases of chronic myelomonocytic leukemia (CMML) was presented. Clinical findings, peripheral blood and bone marrow indices, ultrastructural, cytochemical, biochemical (the level of serum and urine lysozyme), cytogenetic investigations as well as the type of leukemic cell growth in culture (monolayer) were considered. Proceeding from the above analysis, the authors found it appropriate to attribute CMML to myelodysplasia.
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PMID:[Chronic myelomonocytic leukemia]. 323 62

Somatic mutation of the N-ras oncogene occurs frequently in de novo acute myeloid leukemia (AML). By virtue of their relation to AML, myelodysplastic syndromes (MDS) provide an in vivo model of human leukemogenesis. By using a strategy for analysis of gene mutation based on in vitro amplification of target sequences by the polymerase chain reaction (PCR) and selective oligonucleotide hybridization we analyzed the mutational status of codons 12, 13, and 61 of Ha-ras, K-ras, and N-ras in peripheral blood (PB) and/or bone marrow (BM) in 34 cases of primary MDS. Mutations at codon 12 of Ki-ras or N-ras were detected in three cases (9%): one of six cases of refractory anemia with excess blasts (RAEB) and two of nine cases of chronic myelomonocytic leukemia (CMML). The nucleotide substitution differed in each. In all cases the mutant allele was detectable in PB cells. A sustained hematologic remission was achieved after low-dose cytarabine therapy in the case of RAEB. Neither case of CMML exhibited signs of disease progression during follow-up at 7 and 12 months. In contrast, four of 31 patients without the ras mutation underwent transformation to AML within 12 months of genetic analysis. We conclude that ras mutations in MDS are heterogeneous and may develop at an early stage during the evolution of MDS. Their detection in PB cells illustrates the potential utility of ras mutation as a clonal marker in myeloid malignancy.
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PMID:Mutation of Ki-ras and N-ras oncogenes in myelodysplastic syndromes. 328 9

Two cases of childhood myelodysplastic syndrome with chromosome abnormalities involving band 11p15 are described. The first case, with inv(11)(p15q23), had a complex clinical course; the initial diagnosis was aplastic anemia, then refractory anemia with excess of blasts in transformation (RAEB-t), and finally, before death, chronic myelomonocytic leukemia with hematologic features similar to those of chronic myelogenous leukemia (CML). The second case, with t(4;11)(p13;p15), progressed from RAEB to acute myelogenous leukemia (M2). In the literature, we found 12 patients with nonlymphocytic leukemia and chromosome abnormalities involving band 11p15, including seven cases with t(7;11)(p13-p15;p15); four cases (including the present case 1) showed CML-like hematologic features. It is suggested that translocations involving 11p15 are a nonrandom chromosome abnormality in nonlymphocytic leukemia.
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PMID:Childhood myelodysplastic syndromes with 11p15 translocation. 329 71

Responses have been reported in patients with myelodysplastic syndromes (MDS) after low-dose cytarabine (Ara-C) or 13-cis-retinoic acid (13-CRA) therapy. Recently, combination of these two substances in vitro was shown to produce a synergistic effect on differentiation of leukemic cells. We conducted a phase II trial with low-dose Ara-C (5 mg/m2 per 12 h s.c.) and 13-CRA (60 mg/m2 per day orally) in 14 patients with MDS, six of whom had refractory anemia with excess of blasts (RAEB), seven had RAEB in transformation (RAEBt) and one chronic myelomonocytic leukemia (CMML). The drugs were administered from day 1 to 14 and the treatment courses repeated every 4 to 8 weeks. One partial response and one minor response could be achieved. Major toxicity included dry skin, mucositis and cheilitis in 11 of the 14 patients. The response rate is no better than the results reported in the literature with either drugs alone. As yet there is no satisfactory treatment for MDS.
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PMID:Combination of low-dose cytarabine and 13-cis retinoic acid in the treatment of myelodysplastic syndromes. 332 May 77

Chronic myeloid leukaemia (CML) includes five subtypes, and the term should be used in the same way as the term chronic lymphoid leukaemia to refer to a group of related conditions. The subtypes of CML are: 1. Chronic granulocytic leukaemia (CGL) (95% of all CML; 90% are Ph+, BCR+, 5% are Ph-, BCR+); 2. Juvenile CML (extremely rare; Ph-, BCR- in the few so far examined); 3. Chronic neutrophilic leukaemia (CNL) (extremely rare; Ph-, BCR- in the few so far examined); 4. Chronic myelomonocytic leukaemia (CMML). CMML with low or normal leukocyte counts is classified as a myelodysplastic syndrome; CMML with high leukocyte count is both myelodysplastic and myeloproliferative. Ph-, BCR-; 5. Atypical CML (aCML). Intermediate between CGL and CMML but has distinctive features. Ph-, mostly BCR-. Significance of few reported BCR+ uncertain. Markedly worse survival than CGL and probably worse than CMML. Definition needs refining. Types 2, 3, 4 and 5 account for 5% of all CML. CGL, CMML, aCML and CNL can be diagnosed in the great majority of cases from the morphological profile of presentation peripheral blood films, but high-quality Romanowsky staining is essential.
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PMID:Haematological classification of the chronic myeloid leukaemias. 333 55

Forty patients with high risk myelodysplastic syndromes--refractory anemia with excess blasts, refractory anemia with excess blasts in transformation, or chronic myelomonocytic leukemia--were treated with subcutaneous low dose cytosine arabinoside, 10 mg/m2 twice daily for up to 42 days. In 38 evaluable patients there were nine (24%) complete and four (11%) partial responses. Response was associated with symptomatic improvement and resolution of the need for red cell and platelet transfusions. The median duration of complete response was 9.8 months (range, 2.4-17.9); these patients had a median survival of 15.7 months (range, 6.0-22.7). Toxicities were predominantly those associated with pancytopenia, i.e., infection and hemorrhage.
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PMID:Low dose Ara-C for patients with myelodysplastic syndromes. 334 93


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