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)

From 1981 to 1995, we diagnosed, followed and treated at our institution fifty-eight cases of essential thrombocythemia (ET), using hydroxyurea (HU) as first-line therapy in these patients. Three patients who were continuously receiving HU had a leukemic transformation after a chronic phase of respectively 47, 81 and 90 months. One patient developed an acute leukemia with minimal myeloid differentiation (AML MO) and soon died of refractory disease; the second developed a refractory anemia with excess blasts in transformation (t-RAEB) and survived one year; the third patient developed a chronic myelomonocytic leukemia (CMML) and is alive at 21 months. The two former patients had complex nonrandom bone marrow karyotypic abnormalities, suggestive of therapy-related leukemia, whereas the latter one had a normal karyotype throughout the chronic and leukemic phase. These findings, together with recently published results on myeloproliferative disorders (MPD) treated with HU, suggest that this drug might be as leukemogenic as other myelosuppressive therapies in patients with ET. Longterm HU therapy should be reserved for patients in whom the treatment benefits obviously outweigh the risk of inducing leukemia.
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PMID:Is treatment with hydroxyurea leukemogenic in patients with essential thrombocythemia? An analysis of three new cases of leukaemic transformation and review of the literature. 908 33

Refractory anemia with excess blasts in transformation (RAEB-T) is a pre-leukemic syndrome that can progress to acute myelogenous leukemia (AML). Although leptomeningeal disease in AML is rare and it is commonly associated with specific cytogenetic abnormalities, it has not been documented in RAEB-T. We report a woman who experienced seizures and had subarachnoid enhancement on MRI suggestive of leukemic infiltrates in the leptomeninges. Her bone marrow aspirate revealed 6.6% blasts and the presence of Auer rods, findings consistent with a diagnosis of RAEB-T. Subsequent cytogenetic analysis detected an uncommon deletion of chromosome 11q23, and the breakpoint on chromosome 11 is identical to that seen in AML patients having leptomeningeal disease and translocation between chromosome 9 and 11. Although RAEB-T is not considered as leukemia and is thought unlikely to involve the central nervous system, the presence of leptomeningeal disease and 11q23 deletion in our patient suggests that cytogenetic abnormality may be an important determinant of neurological complications, regardless of a diagnosis of RAEB-T or AML which is based on cellular morphology.
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PMID:Leptomeningeal disease in pre-leukemic syndrome: cytogenetic abnormality versus cellular morphology. 946 87

Myelodysplasia (MDS) is mostly characterized by a normal or increased number of normoblasts in the bone marrow and an impaired in vitro colony formation. In the present study we analyzed whether this might be due to a disconnection between proliferation and differentiation. CD34+/CD36- sorted bone marrow cells of 18 MDS patients were cultured in a clonogenic and suspension culture assay in the presence of erythropoietin (Epo) and mast cell growth factor (MGF). Burst-forming units erythroid (BFU-E, 75 +/- 88/10(4) CD34+ cells, X +/- s.d.) and colony-forming units E (CFU-E) were observed in eight of the 13 cases (62%) with refractory anemia with or without ring sideroblasts (RA and RARS) and one of the five cases with RA with excess of blasts or in transformation (RAEB and RAEB-T). Suspension cultures with CD34+/CD36- sorted cells with Epo plus MGF demonstrated an 8.9 +/- 6.5-fold expansion after 7 days in cases with >10 BFU-E/10(4) CD34+/CD36- cells while cases with <10 BFU-E/10(4) CD34+/CD36- cells demonstrated 1.0 +/- 0.8-fold expansion especially in cases with RAEB/RAEB-T. FACS and morphology analysis after 7 days of suspension culture demonstrated partial differentiation along the erythroid lineage in cases with RA/RARS (75%) and RAEB/RAEB-T (66%) reflected by the presence of erythroblasts and normoblasts with variable expression of CD34, CD36 and Glycophorin A. In cases with erythroid colony formation 69 +/- 24% of the cells were CD34-/CD36+ and in cases with <10 BFU-E/10(4) CD34+ cells 18 +/- 16% of cells were CD34-/CD36+. Iron staining showed the presence of ring sideroblasts in two cases with RARS indicating that the cells originate from the abnormal erythroid clone. Finally, it was shown that cases with an impaired proliferative response demonstrate an enhanced binding of Annexin-V on CD34+ cells during the first days of the cell suspension culture phase. These results suggest that a defect in the proliferative response is most pronouncedly expressed in MDS whereas a subpopulation of cells retain the capacity to differentiate between transition to a terminated stage.
Leukemia 1998 Jun
PMID:CD34+/CD36- cells from myelodysplasia patients have a limited capacity to proliferate but can differentiate in response to Epo and MGF stimulation. 1008 48

Fourty children with MDS treated in seven centres of The Polish Children's Leukemia Lymphoma Study Group in period 1975-1998y were included to the study. In 16 children RAEB-T, in 2 CMML in 10 RA and in 12 RAEB were diagnosed. Our and literature data showed that BMT is the best therapy for children with MDS. For children, who don't have a donor for BMT. Roacutan therapy seems to be the most effective.
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PMID:[Treatment outcome for myelodysplastic syndromes (MDS) obtained by the Polish Children's Leukemia/Lymphoma Study Group]. 968 18

Pancytopenia is a frequent manifestation of myelodysplastic syndromes (MDS). In the presence of an empty bone marrow, clinical distinction from aplastic anemia may be difficult. The hypoplastic marrow morphology seen in some cases of MDS raises questions about etiologic and pathophysiologic relationships between aplastic anemia and MDS. The goal of our study was to compare the degree of the hematopoietic failure in these diseases at the level of the most immature progenitor and stem cells that can be measured in vitro. In a systemic, prospective fashion, we have studied bone marrow (n = 45) and peripheral blood (n = 33) of patients with MDS for the number of long-term culture initiating cells (LTC-IC) in comparison to 17 normal controls and patients with new, untreated aplastic anemia (46 marrow; 62 blood samples). Due to the low numbers of cells available for the analysis, formal limiting dilution analysis could not be performed, instead secondary colony-forming cells (CFC) after 5 weeks of LTBMC were measured. As the number of these cells is proportional to the input number of LTC-IC, the number of secondary CFC per 10(6) mononuclear cells (MNC) initiating the LTBMC can be used as a measure of the content of immature stem cells in bone marrow and peripheral blood. The MDS group consisted of 34 RA, three RARS, eight RAEB and two RAEB-T patients with mean absolute neutrophil values of 1992, 1413, 1441, and 380 per mm3, respectively. The diagnosis was established based on bone marrow morphology and results of cytogenetic studies. In comparison to controls (147 +/- 38/10(6) MNC), significantly decreased numbers of bone marrow secondary CFC were found in MDS: in patients with RA and RARS, 21 +/- 7 secondary CFC per 10(6) bone marrow MNC (P < 0.001); patients with RAEB and RAEB-T: 39 +/- 12 CFC per 10(6) marrow MNC (P < 0.001). In all groups tested, the decrease in peripheral blood secondary CFC numbers was consistently less pronounced. In MDS patients with hypocellular bone marrow, secondary CFC were lower but not significantly different in comparison to MDS with hypercellular marrow (18 +/- 6 vs 35 +/- 11; NS; hypoplastic bone marrow also was not associated with significantly lower neutrophil counts). However, in 24% of patients with MDS, bone marrow secondary CFC were within the normal range, while in the aplastic anemia group only one of the patients showed secondary CFC number within normal range. Bone marrow and blood secondary CFC numbers in hypoplastic RA were significantly higher than those in severe aplastic anemia 919 +/- 5 in bone marrow, P < 0.01; 7 +/- 2 in blood, P < 0.05). This trend was even more pronounced in hypoplastic RA with chromosomal abnormalities. However, no significant differences were found between the secondary CFC numbers in hypoplastic RA and moderate aplastic anemia. We concluded that, although the deficiency in the stem cell compartment is less severe in MDS than in aplastic anemia, depletion of early hematopoietic cells is an essential part of the pathophysiology in both diseases.
Leukemia 1998 Aug
PMID:Measurement of secondary colony formation after 5 weeks in long-term cultures in patients with myelodysplastic syndrome. 969 72

Topotecan and retinoids are among the most promising agents being evaluated for the treatment of acute myelogenous leukemia (AML), refractory anemia with excess blasts (RAEB), and refractory anemia with excess blasts in transformation (RAEB-t). Single-agent topotecan is similar to single-agent ara-C, but may be superior in patients with poor-prognosis chromosome abnormalities (ie, -5,-7). Topotecan plus ara-C is equivalent to topotecan alone in chronic myelomonocytic leukemia (CMML), but significantly more effective in RAEB and RAEB-t. Compared with single-agent ara-C, the complete remission (CR) rate with topotecan plus ara-C is comparable, although it offers special advantages in patients with the -5,-7 karyotype. In patients with poor-prognosis cytogenetics, the combination of cyclophosphamide, ara-C, and topotecan, plus all-trans retinoic acid (ATRA) and granulocyte colony-stimulating factor (G-CSF) appears favorable. In a recent study of triple-agent chemotherapy using fludarabine, ara-C, and idarubicin, with or without ATRA and G-CSF, median survival among poor-prognosis patients was 6-7 months, but those who received ATRA did better than those who did not, primarily because it improved survival in those who did not achieve CR. G-CSF produced higher CR rates but had no effect on survival or disease-free survival.
Leukemia 1998 Sep
PMID:New agents for the treatment of acute myelogenous leukemia: focus on topotecan and retinoids. 977 88

Presence of double minute chromosomes (dmin) is rare in bone marrow cells in patients with preleukemia and leukemia. We describe a case of myelodysplastic syndrome-refractory anemia with excess of blasts (MDS-RAEB) associated with two unrelated pathological chromosomal clones that developed during the progression of the disease. The patient was followed cytogenetically for a period of 4 years. At the time of transition into RAEB-T and later to acute myeloid leukemia (AML), dmin were associated with resistance to chemotherapy. Fluorescence in situ hybridization study proved that the dmin in this case were c-MYC amplicons. At the terminal stage of the disease, dmins were present in all 50 analyzed cells.
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PMID:Double minute chromosomes in a patient with myelodysplastic syndrome transforming into acute myeloid leukemia. 997 65

Myelodysplastic syndrome is a closely related group of acquired bone marrow disorders characterized by ineffective and dysplastic hematopoiesis. These clonal disorders frequently progress to acute leukemia. Acute myelomonocytic leukemia with eosinophilia is characterized by an increase in abnormal eosinophils in the bone marrow, relatively good clinical course and inv (16) chromosomal abnormality. We experienced one case of refractory anemia with excess blasts which progressed to refractory anemia with excess blasts in transformation and finally to acute myelomonocytic leukemia with eosinophilia showing peculiar chromosomal abnormalities of der (1;7).
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PMID:Myelodysplastic syndrome that progressed to acute myelomonocytic leukemia with eosinophilia showing peculiar chromosomal abnormality: a case report. 1048 27

Fourty two children with myelodysplastic syndrome (MDS) treated in seven centres of The Polish Paediatric Leukaemia/Lymphoma Study Group in period 1975-1998 were included in the study. In 16 children RAEB-T, in 3 CMML, in 10 RA and in 13 RAEB were diagnosed. BMT is the best therapy for children with MDS. For children, who have not a donor for BMT, Roacutan therapy seems to be the most effective.
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PMID:[How to improve the results of treatment of myelodysplastic syndromes in the studies of Polish pediatric leukemia/lymphoma group]. 1073 43

MLF1 is a novel protein identified as the NPM-MLF1 chimeric protein produced by a t(3;5)(q25.1;q34) chromosomal translocation, which is associated with myelodysplastic syndrome (MDS), often prior to acute myeloid leukemia (AML), except for M3. The clinical features of t(3;5)-positive myeloid disorders suggest that this chimeric protein is involved in dysregulation of progenitor cells with the capability to differentiate into multiple lineages. So far, involvement of wild-type MLF1 in hematopoiesis or in leukemogenesis has not been fully investigated. In the present study, 65 patients with AML and 44 patients with MDS were tested for the expression of MLF1 using the quantitative reverse transcriptase-polymerase chain reaction (RT-PCR) method. A significantly higher level of MLF1 expression (ratio of MLF1/beta-actin mRNA >0.4) was readily detected in seven of 65 patients with de novo AML, three of 12 with post-MDS AML and seven of 44 with MDS, but not in any patients with ALL (n = 18). According to the FAB classification, high levels of MLF1 were found in patients with relatively immature subtypes of AML (M1, M2, M6 and M7) and high risk MDS (RAEB and RAEB-T). These findings indicate that the pattern of MLF1 expression is identical to the clinical morphology appearing in the t(3;5)-positive myeloid disorders and is correlated to the MDS-associated AML and transformation phase of MDS in t(3;5)-negative myeloid disorders. A CD34+ population of normal bone marrow cells preferentially expressed MLF1 with obviously decreasing levels of expression during maturation. Therefore, MLF1 normally functions in multi-potent progenitor cells and its dysregulation may take part in leukemogenesis from MDS.
Leukemia 2000 Oct
PMID:Elevated MLF1 expression correlates with malignant progression from myelodysplastic syndrome. 1102 51


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