Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0023467 (acute myeloid leukemia)
 35,200 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

We describe the clinicomorphological features in 33 cases of primary myelodysplastic syndrome classified according to the FAB classification which presented to a single centre over a 12 year period. Presenting features were typically related to pancytopenia although hepatosplenomegaly and granulocytic sarcomas were far more prevalent than in the adult population. Morphological assessment of the peripheral blood and the bone marrow showed seven patients had refractory anaemia (RA), 13 patients had RA with excess of blasts (RAEB), nine patients had RAEB in transformation (RAEB-t) and four patients had chronic myelomonocytic leukaemia (CMML). The overall mean survival was short (9.9 months) in all the subgroups and the leukaemic transformation rate was high. None of the patients scored 0-1 according to the Bournemouth Scoring System; four patients scored 2 whereas 29 patients scored 3 to 4. We conclude that unlike adults, the myelodysplastic syndromes in children run an aggressive clinical course, irrespective of the FAB subtype, and the pathogenesis of these diseases in paediatric practice warrants scientific scrutiny. Intensive chemotherapy such as the one used in de novo-AML lead to complete remission in some children and these early results suggest that this should be the treatment of choice in paediatric MDS.
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PMID:Primary myelodysplastic syndrome in children: the clinical experience in 33 cases. 141 17

The activation of protooncogenes (ras, fms and myc genes) by point mutations in hematological malignancies are described in this review. Ras mutations are found in a variety of human malignancies at codon 12, 13, and 61. Generally, N-ras mutations are frequent in hematological malignancies. Fms mutation at codon 301 and 969, which are seen in 10 to 20% cases of AML and MDS, increase tyrosine kinase activity of the fms products. Ras and fms mutations are postulated to influence leukemogenesis at rather early stages. Burkitt lymphomas are characterized by specific chromosomal translocations between c-myc gene and one of the immunoglobulin genes. Furthermore, mutations in the 3' border of the exon 1 of c-myc are frequent, and may play an additional role in pathogenesis of Burkitt lymphoma.
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PMID:[Activation of protooncogenes by point mutations in hematological malignancies]. 151 54

Aggressive chemotherapy of myelodysplastic syndromes is rarely feasible because these disorders predominantly occur in elderly patients who often have concurrent illnesses. Alternative treatment modalities must therefore be evaluated. This review summarizes the results that have been obtained with low-dose chemotherapy, especially with low-dose cytosine arabinoside (Ara-C). Overall response rates to treatment with low-dose Ara-C are about 40%, with some 20% of patients achieving a complete remission. Transition of MDS to AML does not reduce the probability of response. The therapeutic outcome cannot be reliably predicted by clinical or experimental parameters. Hematological toxicity is substantial, with approximately 10-25% treatment-related deaths. Duration of response is short and rarely exceeds one year. In terms of overall survival, low dose Ara-C does not appear to be superior to supportive care only. Other cytotoxic agents have not been studied in detail, but data available do not suggest an appreciable advantage over Ara-C. Before denying low-dose chemotherapy a helpful role in MDS, randomized studies should concentrate on those patients who can be expected to derive the greatest benefit. Because of their short survival, patients with RAEBt or those transformed to overt leukemia are such candidates.
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PMID:The role of low-dose chemotherapy in myelodysplastic syndromes. 156 Jun 70

In a retrospective study of 352 patients with primary myelodysplastic syndromes, 61 (17.3%) revealed myelofibrosis in bone marrow biopsies. The fibrosis was observed to occur mostly focally (41/61 cases), and collagen deposits were found very rarely (4/61). The histopathology of bone marrow biopsies revealed hyperplasia and disturbed differentiation in megakaryopoiesis; the frequency and grade of dysplasia in megakaryopoiesis increased with advancing myelofibrosis. Reticulin fibrosis occurred in all subtypes of MDS; however, there was a higher incidence in chronic myelo-monocytic leukaemia (CMMoL). The frequency of cytogenetic aberrations was significantly higher in the MDS cases with myelofibrosis, compared to the cases without fibrosis. Clinical data showed significantly lower values of haemoglobin and lower platelet counts in MDS with myelofibrosis. Life expectancy was reduced to 9.6 months, compared with 17.4 months in MDS without fibrosis. In refractory anaemia, the survival times were 10.0 months in MDS with myelofibrosis, compared to 28.9 months in MDS without myelofibrosis. 36.6% of the patients with MDS and myelofibrosis developed a transformation into ANLL during the course of the disease. Myelofibrosis therefore seems to herald a poor prognosis.
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PMID:Myelofibrosis in primary myelodysplastic syndromes: a retrospective study of 352 patients. 159 1

Myelodysplastic syndromes originate from a pluripotent stem cell. This view, previously suggested by G-6-PD and cytogenetic investigations, has been established unequivocally by X-chromosome inactivation analysis based on DNA polymorphisms and by studies of mutated oncogenes. Two genomic alterations associated with MDS have been analyzed in more detail. Activation of the RAS oncogenes, preferentially N-RAS, is demonstrated in approximately 35% of MDS patients. Mutations in the FMS gene, encoding the CSF-1 receptor, are found in 16% of cases. Interestingly, RAS and FMS mutations are predominantly observed in disorders of myelomonoctic differentiation, i.e., the CMML subtype in MDS and the AML FAB type M4. Moreover, homozygous deletion of the FMS gene may be an important event in the genesis of the MDS variant 5q- syndrome. Preliminary data indicate that defects in tumor-suppressor genes, namely p53, may also contribute to the development of MDS. Different lines of evidence suggest that clinical preleukemia is preceded by a phase in which genetic alterations accumulate without any hematologic change. Cases in point are the detection of RAS and FMS mutations in healthy individuals who had been treated in the past with cytotoxic therapy for lymphoma, the frequent observation of clonal remission in AML patients, or the identification of oncogene mutations in healthy individuals without even a history of malignancy or chemotherapy. Possibly, either germline mutations of oncogenes or tumor-suppressor genes and the process of genomic imprinting may constitute additional factors that predispose hematopoietic stem cells to malignant transformation. Limited as they are, the currently available data suggest that accumulation of genomic lesions, rather than their precise order of development with respect to one another, characterize the multistep process of leukemogenesis in which MDS already represent more advanced stages. The prognostic significance of oncogene mutations in MDS patients is controversially discussed. This issue awaits prospective analyses taking into account the influence of treatment modalities. However, the clinical relevance of molecularly defined parameters has already been established for their use as clonal markers in determining the mode of action and efficiency of different therapeutic approaches.
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PMID:Molecular genetic aspects of myelodysplastic syndromes. 161 6

Thirty-four patients with MDS or AML following MDS were studied with regard to survival, peripheral blood values and bone marrow morphology. The effects of 1,25 dihydroxyvitamin D3 (D3) on differentiation (NBT positivity) and proliferation (3H-thymidine incorporation) were studied in suspension cultures of bone marrow cells. Twelve bone marrow donors served as controls. Normal cells showed spontaneous differentiation in vitro, but only 2/12 were induced to differentiation by D3. Myelodysplastic cells did not differentiate spontaneously, but cells from 18/34 patients differentiated after incubation with D3. Normal cells showed increased proliferation, myelodysplastic cells showed a heterogeneous response and leukemic cells reacted with decreased proliferation after D3 incubation. Poor survival was associated with low platelet counts, high percentage of bone marrow blasts (BM blast %), low spontaneous in vitro proliferation and absence of hypogranulation of myeloid cells. Platelet counts and hypogranulation retained their predictive value in a multi-variate analysis. Progression to AML was predicted by a high BM blast % and low scores for erythroid and total dysplasia. In conclusion, the pattern of in vitro proliferation showed prognostic value while the pattern of vitamin D3-induced differentiation failed to correlate to other parameters. An estimation of bone marrow dysplasia can be used to predict the development of AML. Our results add to the information about the biology of MDS and may be important for the evaluation of therapeutic trials.
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PMID:In vitro suspension culture reactions to 1,25 dihydroxyvitamin D3 in relation to bone marrow morphology and prognosis in patients with myelodysplastic syndromes. 162 79

A female patient in whom acute nonlymphocytic leukemia (ANLL, FAB-M6) developed during treatment of hepatocellular carcinoma (HCC) is described. Two years after partial hepatectomy and subsequent chemotherapy, leukemia developed following a 2 month preleukemic stage. Chromosomal analysis revealed an abnormal karyotype, 46,XX,-5, + der(5)t(3;5)(q25;q31). The balanced translocation t(3;5) has been observed in all types of ANLL and MDS except for ANLL M3 subtype. We summarize patients with ANLL M6 and t(3;5).
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PMID:Acute erythroleukemia with t(3;5) accompanied by hepatocellular carcinoma. 166 Jul 36

The object of this study was to determine whether the "in vitro" parameters of medullary and blood granulopoiesis in patients with MDS, furnish information of either prognostic or diagnostic value. This study covered 94 patients with MDS. All patients were studied at the onset of disease. In order to identify the factors related to patients' survival, Cox Multiple Regression analysis was performed by the BMD P2L program. When analyzing by means of actuarial curves the survival probability of patients with benign development versus those of malignant development (those who developed ANLL), the significance between both groups was p = 0.0001. Different variables of patients included in this study were analyzed and all showed great significances. Fab: p = 0.0022, disease evolution: p = 0.0001 and presence of blastic aggregates: p = 0.0011. Cox's regression analysis revealed that the only predictable survival variable is the presence of blastic colonies and/or clusters. Accordingly, two groups were constructed: favourable and unfavourable. In the favourable group, 40% of the patients belonged to the RA group, while in the unfavourable group, 55% belonged to the RAEB group. This study shows the validity of the elaboration of prognostic groups in MDS according to the presence of blastic colonies and/or clusters in CFUGM medullary and/or peripheral cultures. The "in vitro" myeloid progenitors culture techniques may therefore be advantageously applied in these disorders for formulating a diagnosis and predicting the patient's short term evolution.
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PMID:The myelodysplastic syndrome: prognostic factors in relation to the "in vitro" clonogenic assay. 169 68

Clinical, haematological, cytogenetic features and therapeutic problems of 51 patients with MDS were examined. Patients were distributed in 5 FAB subgroups: RA 21, SA 7, RAEB 8, RAEB-t 9 and MMCL 6 patients. Leukaemic transformation occurred in 3 RA, 3 RAEB, 7 RAEB-t and 3 MMCL patients. No SA patient suffered from leukaemic transformation. Cytogenetic alterations occurred in 13 of 29 examined patients; 5q- was the most common abnormality. We did not find any relation between chromosomal anomalies and FAB subgroups. Leukaemic transformation, however, was more frequent in patients with cytogenetic aberrations. In some cases it was not easy to determine the precise diagnostic allocation according to FAB subgroups; it is possible, however, to subdivide MDS prognosis into 2 classes. The more satisfactory therapy of leukaemic transformation is often due to low doses of Ara-C; this therapy allowed a better survival and sometimes to obtain CR which in a M6 ANLL patient continued for 24 months.
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PMID:Myelodysplastic syndromes: analysis of 51 cases. Therapy with low doses of arabinosyl cytosine of leukaemic transformation. 169 90

Blast-cells in Romanowsky-Giemsa stained bone marrow smears from 14 cases of primary myelodysplastic syndrome which consequently developed an acute myeloid leukemia and 28 cases of primary acute myeloid leukemia were analysed by a computer aided high resolution pattern recognition system. As control we used blast-cells from reactive affected bone marrow. Whereas blast-cell types in MDS and secondary AML showed overlapping features and a heterogenous distribution we could distinguish blasts in primary AML compared to "reactive" blasts. Opposite to this blasts in secondary AML showed no different pattern compared to "reactive" blast.
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PMID:[Pattern analytic investigations of blast cells in myelodysplastic syndrome and secondary acute myeloid leukemia]. 170 71


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