Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UMLS:C0026986 (myelodysplastic syndrome)
 14,926 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

A transplantation bioassay method was used to verify the presence of preleukemia cells in C57BL/6 mice shortly after leukemogenic treatment or in relation to age increase. Preleukemia cells were identified mainly among bone marrow cells of old C57BL/6 mice or within 10 to 30 days after leukemogenic treatment of young mice with radiation-induced leukemia virus variants, fractionated doses of irradiation, or 7,12-dimethylbenz[a]anthracene (DMBA), although the overt disease did not occur until many months later. Mice could carry preleukemia cells without necessarily developing overt leukemia. Since the leukemogenic agents used in the present studies induced T-leukemias, the role of the thymus in the induction of preleukemia cells was tested. Thymectomy affected viral transformation but did not diminish the number of preleukemia cells induced by DMBA or X-ray.
 ...
PMID:Spontaneous and induced preleukemia cells in C57BL/6 mice:brief communication. 20 13

Bone marrow cells from three preleukemic patients with prominent marrow karyotypic abnormalities were studied in liquid culture to determine if the neoplastic clones were capable of maturation. Parallel cytogenetic and cytologic studies were performed in sequentially harvested bone marrow cultures. Maturation, albeit delayed, occurred in cultures from all three patients. By 14 days of culture in vitro, morphologic, cytochemical, and functional evidence of maturation was observed in about 70% of the cells. By day 21, 85% of the cells were mature by these criteria. All but 2 of 249 metaphases from the cultured cells contained the cytogenetic abnormality of the neoplastic clone. We conclude that some preleukemic cells identified by a chromosomal abnormality can mature in vitro. Preleukemia may be viewed as a syndrome of "early leukemia" in which the neoplastic clone is established and manifested functionally as ineffective hematopoiesis. Hematopoietic cell differentiation becomes progressively abnormal with termination in the nearly complete maturational block characteristic of acute myelogenous leukemia.
 ...
PMID:Cellular maturation in human preleukemia. 27 87

The six cases of Preleukemia (or Preleukemic States) are described. The peripheral blood was characterised with Pancythopoenia in 5 and bicytopoenia in 1 patient. Morphological alterations of Erythrocytes were present in all cases. The Bone Marrow was hypercellular in 3 and hypocellular in 3 patients. Erythropoiesis was megaloblastic or partly megaloblastic in 5 cases, with "ring" sideroblasts present in all cases. The percentage of Leukemic blast cells was as follow: 0, 5, 6, 10, 30 and 33. The duration of the preleukemic phase varied from 3-53 months. With the manifestations of overt Acute Nonlymphatic Leukemia the agressive therapy was applied. The results were poor in 5 patients (the survival 1, 5-4 m.). Only one survived more than 60 months and is still in full remission.
 ...
PMID:[Preleukemia]. 60 31

In preleukemia and in remission of acute leukemia abnormal mononuclear cells ("string of bead" cells) have been observed and characterized with cytochemical methods. These cells may be resistant to cytostatic therapy and may be characterized as a source of a newly developing leukemic blast cells. Preleukemia and leukemic remissions seem to be identical states. Based on the morphological and cytochemical parallelity of cells in CFU-c-enriched fractions of the bone marrow and the so called string of bead cells we consider these cells to be closely related to the human commited stem cell.
 ...
PMID:Cytochemical observations in preleukemic states and remission of akute leukemia. 88 Mar 77

Preleukemia is thought to be a clonal disorder of hemopoietic stem cells. The conversion of a normal cell into a preleukemic and ultimately leukemic state is a multistep process requiring the accumulation of a number of genetic lesions. The myelodysplastic syndromes have become a paradigm for human preleukemia, where nonrandom chromosomal abnormalities, including complete or partial deletions of chromosomes five and seven, trisomy eight and Y chromosome loss suggest specific changes. Of particular significance are 5q deletions, as many genes important in hemopoiesis are located in this region, including the proto-oncogene FMS, which encodes the receptor for the macrophage colony-stimulating factor, CSF-1. Genetic damage such as point mutations in the RAS and FMS genes has been detected in preleukemia patients. The RAS gene family (N, K and H) encodes membrane-bound G proteins, which, like other proto-oncogenes, are components of the intracellular signal transduction pathways controlling mitogenesis and differentiation. The characterization of such lesions may ultimately identify those patients at greatest risk of leukemic transformation.
 ...
PMID:Genetic lesions in preleukemia. 142 Apr 44

Hematological and cytogenetic characteristics of 75 cases of therapy-related acute non lymphoid leukemia (t-ANLL) occurring in Hodgkin's disease (HD) are analysed in this multi-institution study. Combined radio and chemotherapy had been given in 88 per cent of patients, either as adjuvant (44 per cent) or as salvage modality (44 per cent). Radiotherapy alone and chemotherapy alone had been given in 3 per cent and 9 per cent respectively. Eighty per cent of patients were in remission of HD and 71 per cent off-therapy while developing leukemia. The median latent time from remission of HD to leukemia was 34 months. The myeloblastic variety of leukemia accounted for 43 per cent of total cases; the myelomonocytic and monocytic for 17 per cent and 4 per cent, the promyelocytic and erythroblastic variants for 5 per cent and 7 per cent of t-ANLL. Twenty four per cent of cases were unclassifiable; one of these was TdT-positive. Dysplastic features of erythrocytic line were invariably present with circulating erythroblasts; defects of granulocytes, circulating megathrombocytes and micromegakaryocytes were also present. Bone marrow hypoplasia and marked fibrosis were documented in 47 per cent and 30 per cent of cases. Preleukemia heralded overt leukemia in 73 per cent of cases; 37 per cent had refractory anemia with no excess of blasts; 16 per cent of preleukemias were unclassifiable. Cytogenetics revealed chromosome abnormalities in 83 per cent of cases; 72 per cent presented chromosome 5 and/or 7 monosomy or partial deletion (5q- or 7q-) of the long arm (94 per cent in the combined modality therapy group). In 3 cases, a pure monosomy 7 was observed; in none 5q-alone. Response rate to conventional therapy was 14 per cent; low and high-dose cytarabine were of little benefit. Long-term CR (28 + and 16 + months) was achieved in 2 cases with allogeneic bone marrow transplantation (BMT) as first-line therapy. A better knowledge of t-ANLL in HD and new therapies, including BMT, may improve the prognosis of this late complication of intensive HD treatment.
 ...
PMID:Treatment-related leukemia in Hodgkin's disease: a multi-institution study on 75 cases. 243 31

Preleukemia has generally been treated by palliative measures. Several reports have indicated that cytarabine given as low-dose infusion results in responses, albeit short lived, in a fraction of patients. We have shown recently that marrow transplantation offers a useful alternative. Twelve patients have been treated and followed for a minimum of 1 year. Three were conditioned with cyclophosphamide (CY) only, and all died with recurrent or persistent disease. Nine were conditioned with CY and total-body irradiation; all but 1 had lasting engraftment, and 7 are surviving, free of disease, 16-36 (median 27) months after transplantation. These data show that marrow transplantation can provide successful therapy for preleukemia.
 ...
PMID:Marrow transplantation in preleukemia. 352 76

The clinical and cell growth characteristics of 11 children with monosomy 7 presenting as preleukemia (eight cases) or acute nonlymphoblastic leukemia (three cases) were studied. Anemia was common to all patients, with nine showing leukocytosis, seven thrombocytopenia, and one thrombocytosis. There was a striking predominance of males (M/F ratio, 10:1) and a young median age (3 years). Preleukemia evolved to acute nonlymphoblastic leukemia in five patients and to myelofibrosis in one. In vitro studies of bone marrow progenitor cells cultured in leukocyte feeder-stimulated agar revealed abnormal cell proliferative patterns, most often an increased number of small clusters, for all 11 subjects. The cells of some preleukemic patients showed increased growth even in the absence of an exogenous source of colony-stimulating factor, suggesting autonomous growth or possibly autocrine stimulation. Combination chemotherapy or bone marrow transplantation failed to induce complete remission in the seven patients who were treated. Our findings in these 11 cases confirm the poor prognosis of monosomy 7 presenting as preleukemia in children. The in vitro studies suggest an association between altered cell growth in vitro and clinical evolution to frank leukemia.
 ...
PMID:Childhood monosomy 7 syndrome: clinical and in vitro studies. 366 40

Preleukemia is a well-defined syndrome of hematopoietic dysfunction that may antedate the development of acute myelogenous leukemia. Granulocytic sarcoma refers to neoplastic infiltration in the skin, composed of immature cells of the granulocyte series. We report two cases of granulocytic sarcoma in the setting of preleukemia. The clinical importance of these cases, as well as the cutaneous manifestations of leukemia and the clinical spectrum of granulocytic sarcoma, are presented.
 ...
PMID:Granulocytic sarcoma. A new finding in the setting of preleukemia. 659 7

Preleukemia refers to the syndrome of hematopoietic dysfunction seen in some patients before typical features of acute myelogenous leukemia develop. Clinically, preleukemia is characterized by variable degrees of pancytopenia, with associated symptoms due to decreased circulating blood elements. The bone marrow is usually hypercellular, and there are prominent morphologic abnormalities in erythroid precursors and more subtle changes in megakaryocytes and granulocyte progenitors. During this phase of the leukemic process, the neoplastic clone is usually already established and predominant. A clear distinction should be made between the preleukemic syndrome and diseases that predispose to development of acute myelogenous leukemia. Preleukemia, like acute myelogenous leukemia, is a clonal hematopoietic stem cell neoplasm manifested functionally by abnormal hematopoietic cell maturation and ineffective hematopoiesis. During the course of preleukemia, precursor cell maturation becomes progressively impaired with termination in the severe maturational block characteristic of acute myelogenous leukemia. We favor the concept that preleukemia is an early phase of acute myelogenous leukemia.
 ...
PMID:Human preleukemia. 693 7


1 2 Next >>