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)

Particles with the density and enzymatic activity characteristic of known oncornavirus have been previously described in bone marrow cells from patients with leukemia in relapse and in remission. We have confirmed these findings and studied two patients in whom preleukemia was among the diagnostic considerations. Following cultivation of bone marrow from these patients for 1 week in conditioned media with dexamethasone, a high-speed pellet of the supernatant fluid and disrupted cells was prepared and analyzed on a sucrose gradient for enzymatic activity characteristic of RNA-directed DNA polymerase (reverse transcriptase). Peaks of endogenous DNA polymerase activity showing ribonuclease sensitivity and/or stimulation with the synthetic template poly(rC)-(dG)12-18 were demonstrated in both patients at densities of 1.15 to 1.19 and 1.21 to 1.24 g/ml. Subsequently, diagnosis 2 and 4 months after initial evaluation revealed acute myelogenous leukemia and malignant histiocytosis, respectively. Prior studies have suggested a possible etiological significance of such particles in human leukemia. The demonstration of similar particles preceding clinically overt disease in these patients supports this hypothesis and offers the possibility of early diagnosis and treatment.
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PMID:Oncornavirus-like particles from cultured bone marrow cells preceding leukemia and malignant histiocytosis. 5 58

In man, hematologic abnormalities precede the development of acute myeloblastic leukemia in about one-third of individuals. This preleukemic state may represent a stage of adult leukemia wherein small numbers of leukemic cells are present and the normal marrow stem cell compartment has not been seriously compromised. A syndrome resembling human preleukemia occurs in cats infected with feline leukemia virus (FeLV). This disorder is characterized by anemia, leukopenia or thrombocytopenia occurring weeks or months prior to the development of feline acute leukemia. The natural occurrence of this syndrome in this domestic animal population makes it a potential model of human preleukemia. Initial poor results of therapy of human preleukemia presently prohibit one from carrying out controlled trials with chemotherapeutic agents in such a group of patients. Preliminary trials with chemo- and/or immunotherapy may be more easily attempted with FeLV infected preleukemic cats.
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PMID:Feline preleukemia: an animal model of human disease. 22 Aug 6

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.
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PMID:Cellular maturation in human preleukemia. 27 87

Acute myeloblastic leukemia, like certain other hematologic disorders, originates in pluripotent stem cells. Two general biologic processes underlie development of the disease. Over long times, clonal progression leads from normal polyclonal hemopoiesis through clonal preleukemia to leukemia. Overt leukemia is characterized by the emergence of blast cell populations. Over shorter times, clonal expansion yields cellular diversity based upon randomizing events. The analysis indicates that that blast population is of crucial importance. Characteristics of a colony assay for blast cell progenitors are presented.
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PMID:Acute myeloblastic leukemia considered as a clonal hemopathy. 29 69

The classification of acute leukemia has almost invariably been based on the morphologic diagnosis into two broad categories: acute lymphocytic and acute myeloid leukemia. Despite the wide range of morphologic variation in both groups, strict criteria to define the subgroups have only recently been proposed. The conventional markers for B and T cells are now being applied to leukemic cells as are cytochemistry and electron microscopy, terminal deoxynucleotidyl transferase, serum lysozyme, and surface markers, E-rosettes, membrane immunoglobulin, antinull acute lymphocytic leukemia antiserum, and Fc and C3 receptors. The myelodysplastic syndromes may mimic acute leukemia and it is important that they be identified and treated appropriately. The high incidence with which chronic myelomonocytic leukemia terminates in acute leukemia suggests that it is a preleukemic condition, whereas refractory anemia with excess blasts and acquired idiopathic sideroblastic anemia may have long, drawn-out courses. Only a small population of patients with the latter conditions develop acute leukemia.
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PMID:Classification of acute leukemia. 33 70

The distribution of various types of leukemia due to chronic exposure to benzene is described in a series comprising 34 cases. The incidence of leukemia among 31 show-workers was 13.5/100,000. Acute myeloblastic leukemia was the most frequent type, followed by preleukemia, acute erythroleukemia and acute lymphoblastic leukemia. The extreme rarity of chronic myeloid leukemia was a noteworthy finding. The differences and similarities between the distribution of various types of leukemia in different series of patients with chronic exposure to benzene and ionizing radiation are discussed.
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PMID:Types of leukemia in chronic benzene poisoning. A study in thirty-four patients. 81 44

Bone marrow from patients with acute myelogenous leukemia (AML), acute myelomonocytic leukemia (AMML), chronic myelogenous leukemia (CML), preleukemia, and from healthy volunteers was cultured using a recently developed liquid diffusion technique. Differential and viable cell counts and 3H-thymidine labeling indices were performed at intervals up to 30 days. Differentiation was assessed morphologically by light and electron microscopy, histochemically, and by functional tests for phagocytosis and the presence of surface receptors for IgG. Colony-stimulating activity (CSA) was assayed against normal human bone marrow by the agar colony technique. In acute leukemia cultures, viable cell counts usually fell within the normal range. However, most AML cells failed to demonstrate significant maturation in vitro, and did not produce detectable CSA. In AMML cultures, maturation was defective but some differentiated macrophages were observed and the cells produced high concentrations of CSA. Preleukemic cultures demonstrated normal growth but maturation was impaired as evidenced by a high percentage of immature cells during the first 7 days. CML cultures showed abnormally high growth capacity resulting in viable cell counts 2-3 times normal. In the chronic phase of CML, maturation was qualitatively normal and the cells produced CSA. With the onset of blast transformation, maturation became abnormal but growth remained high. These studies support a concept of AML as a primary defect in cellular maturation and of CML as a primary abnormality of proliferation. The production of CSA by neoplastic cells relates to the degree of monocyte-macrophage differentiation within the leukemic population. Human preleukemia is characterized by a failure of normal maturation in vitro.
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PMID:Proliferation and maturation of human leukemia cells in liquid culture. 105 46

The kinetics of erythropietic and granulocytopoietic cell proliferation have been investigated in the same patient at two distinct stages: firstly in preleukemia presenting as pancytopenia with ineffective erythropoiesis, and secondly 2 years later in acute myelogenous leukemia. The method investigation is based on determining the DNA synthesis rate of individual cells by means of quantitative 14C-autoradiography after short-term incubation with 14C-thymidine and fluorodeoxyuridine. Erythropoiesis was equally ineffective in the two stages, the rate of proliferation, however, slowed down towards the leukemic state. The production rate of myeloblasts was markedly reduced in preleukemia accompained by a very low labelling index. In leukemia on the other hand the production rate was increased to such a degree that the leukemic myeoblast compartment is to be considered as prevailingly self-reproductive. The proliferation rate of myeloblasts was reduced already in preleukemia, and there was a further decrease in leukemia. From the point of view of cell kinetics the manifestation of leukemia in this patient is explained best by a change in the mode of proliferation: the myeloblasts change from steady state growth to behaving like an exponentially expanding population.
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PMID:Proliferation and production of hemopoietic cells two stages of disease: preleukemia and overt leukemia. 106 31

Cytogenetic abnormalities have been found in approximately 50% of all patients with acute leukemia. Although no chromosomal abnormalities have been found which are characteristic of a specific cell type, patients with AML and DiGuglielmo's syndrome more frequently have hypodiploid chromosome numbers, while patients with ALL seldom have hypodiploid numbers of chromosomes and may actually exhibit an extreme degree of hyperdiploidy in the leukemic cells. Chromosome analysis may be helpful in characterizing patients with preleukemia and DiGuglielmo's syndrome, and aneuploidy may correlate with shortened survival in these conditions. Although data so far available are conflicting concerning the relationship of aneuploidy to response to therapy in patients with acute leukemia, it is possible that as improved therapeutic regimens become available for the treatment of acute leukemia, more sophisticated cytogenetic analysis may be helpful in predicting survival and response to therapy.
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PMID:Cytogenetic heterogeneity of the acute leukemias. 106 28

In acute myeloid leukemia (AML), many of the remaining normal-appearing cells exhibit various abnormalities. An interpretation is that these cells are descendants of leukemic cells which have succeeded in overcoming the major final differentiation block that exists in AML. Direct evidence is quoted that red cell precursors in AML are of leukemic descent and it is claimed that the target cell of AML is the pluripotent stem cell. Next, evidence has been compiled that all three cell lines (red cell, n. granulocytes, platelets) exhibit qualitative defects in "prelukemia." Hence it is postulated that preleukemia per se doses not exist but that preleukemic states which with a rather high frequency sooner or later end in overt AML are actually true leukemias that, however, differentiate reasonably well. Another way of phrasing it is that preleukemic states are AMLs that present in partial and sometimes long-lasting remission, which only after months to years lose their differentiation ability and then are classified as AML.
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PMID:Preleukemia: does it exist? 106 74


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