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Query: UMLS:C0023418 (leukemia)
 93,477 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

We have investigated proliferation in bone marrow trephine biopsies from 32 patients with normal or abnormal haemopoiesis, using the monoclonal antibody PC10, which detects proliferating cell nuclear antigen (PCNA), together with immunohistochemical markers of haemopoietic cell lineage. PCNA immunostaining revealed the pattern of proliferation within individual haemopoietic lineages in normal marrow. Two unexpected observations were made: of erythroid cells, only pro-erythroblasts and occasional early normoblasts reacted, and positivity of megakaryocytes was unrelated to nuclear lobulation or CD61 expression. The pathological cases represented conditions in which haemopoiesis is increased (reactive hyperplasia, chronic granulocytic leukaemia, myeloproliferative and myelodysplastic syndromes, megaloblastic anaemia). Increases in the number, and disturbances of the spatial organization, of PCNA-expressing cells were present to a variable extent in all cases. Sheets of PCNA-positive megaloblastoid erythrocytes were frequently found in myelodysplastic and myeloproliferative tissue, associated with marked disturbances in the spatial organization of all haemopoietic lineages. Cases of megaloblastic anaemia due to vitamin B12/folate deficiency also demonstrated greatly increased erythroid PCNA expression, with positivity in some giant metamyelocytes. In addition to reflecting increased proliferation, elevated PCNA expression in some bone marrow pathologies may be due to altered kinetics of the protein induced by disturbances in growth factor production.
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PMID:A study of cell proliferation in formalin-fixed, wax-embedded bone marrow trephine biopsies using the monoclonal antibody PC10, reactive with proliferating cell nuclear antigen (PCNA). 134 81

Cutaneous extramedullary hematopoiesis is rare, usually occurring in neonates following intrauterine viral infections, hereditary spherocytosis, or the twin transfusion syndrome. Only 20 cases of cutaneous extramedullary hematopoiesis have been reported in adults, all with myelofibrosis. The cutaneous infiltrates may be atypical and difficult to distinguish from leukemia cutis. We have studied a 65-year-old woman with myelofibrosis and approximately 40 violaceous, firm, non-tender cutaneous nodules measuring 1 to 4 cm in diameter, located on her abdomen near a splenectomy scar. Histologically, the lesions had a dense infiltrate of myeloid cells in all stages of maturation, atypical large cells with multilobate nuclei or multiple nuclei, resembling atypical megakaryocytes, and fibroblasts. Although the patient received erythropoietin therapy prior to the development of the nodules, erythroid progenitors were not seen. Reticulin was increased particularly surrounding the atypical megakaryocytes. The myeloid cells stained for chloroacetate esterase and with the polyclonal antibody MAC 387. Atypical megakaryocytes stained for Factor XIIIa and Factor VIII-related antigen. Dendritic Factor XIIIa positive cells were also increased. The skin lesions remain unchanged grossly one year after their development.
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PMID:Cutaneous myelofibrosis. 135 14

We investigated the expression profiles of lacto-series type 2 antigens in hematopoietic cells and their progenitors, in comparison with leukemic leukocytes. Reactivity profiles of various anti-type 2 chain monoclonal antibodies (MoAbs) with leukemic blasts from 12 patients with acute myeloblastic leukemia (AML) and those from two patients with acute unclassified leukemia (AUL) show that anti-sialosyl-Le(x) MoAb SNH3 reacted strongly with greater than 95% of leukemic blast leukocyte populations from all patients (14 of 14). Another anti-sialosyl-Le(x) MoAb, FH6, showed less reactivity than SNH3 (12 of 14 patients), while anti-Le(y) MoAb AH6 showed reactivity with only 8 of 14 patients. On the other hand, none of the anti-type 2 chain MoAbs reacted with CD34+ normal adult bone marrow (BM) mononuclear cells obtained independently from three healthy volunteers. MoAb SNH3, but not FH6 or AH6, showed complement-mediated cytotoxicity to leukemic blasts from these patients, as well as to myelogenous leukemia cell line HL60. Colony-forming unit granulocyte-macrophage (CFU-GM), but not burst-forming unit-erythroid (BFU-E), was incompletely inhibited by treatment of normal BM mononuclear cells with SNH3 and complement. The absence of type 2 chain antigen expression in hematopoietic progenitor cells and in in vitro hematopoietic colonies (CFU-GM and BFU-E) strongly suggests that application of anti-carbohydrate MoAbs, particularly anti-sialosyl-Le(x) could be useful for elimination of leukemic myeloblasts infiltrating in BM, for purging of leukemic blasts in BM, and for facilitation of autologous BM transplantation.
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PMID:Reactivity profiles of leukemic myeloblasts with monoclonal antibodies directed to sialosyl-Le(x) and other lacto-series type 2 chain antigens:absence of reactivity with normal hematopoietic progenitor cells. 137 Jun 43

We have compared the sequence of the 5' hypersensitive site-2 (5'-HS-2) of the locus control region (LCR) from a sickle cell anemia (SS) patient homozygous for haplotype 19 and with low levels of fetal hemoglobin (HbF), with the same sequence from an SS patient homozygous for haplotype 3 and with high levels of HbF. Several nucleotide variations were present in the 5'HS-2 of the haplotype 19 individual. One is the A----G at position -10905 that creates an Sp1 binding site GCCCC (A----G)CCCC. A second is the T----G at position -10924 in a sequence that binds both erythroid and ubiquitous factors and exhibits high homology to the long terminal repeat of the Moloney leukemia viruses and Friend murine leukemia virus. Other differences were in the two AT-rich stretches of DNA, and an A----T substitution at position -10390. Dot-blot analyses of amplified DNA from several SS patients showed that these variations are specific for beta S chromosomes with haplotype 19. We also examined the 5'HS-2 sequence from an SS patient who is homozygous for haplotype 19, but has abnormally high levels of HbF (greater than 20%). We observed a cross-over that has placed sequences similar to the 5'HS-2 of haplotype 3 in juxtaposition to the 5' flanking regions of haplotype 19. Thus, a beta S chromosome with haplotype 19 but having a 5'HS-2 (LCR) characteristic for haplotype 3 is associated with high gamma-chain expression. We postulate that factors produced under conditions of hematopoietic stress, together with genetic determinants on the haplotype 3-like LCR sequences, allow for high level expression of gamma-globin genes.
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PMID:Sequence variations in the 5' hypersensitive site-2 of the locus control region of beta S chromosomes are associated with different levels of fetal globin in hemoglobin S homozygotes. 137 Jun 46

Established cell lines were screened for secretion of activities than can stimulate fetal hemoglobin (HbF) production in adult burst-forming unit-erythroid (BFUe) cultures. Conditioned media from four cell lines, a human teratocarcinoma, an osteosarcoma, a bladder cell carcinoma, and feline leukemia virus (FeLV) A-infected feline fibroblasts (FEF-A cells), consistently increased the relative production of fetal globin in BFUe-derived colonies. In vitro translation of RNA from these cells in Xenopus oocytes yielded products that increased the gamma to gamma+beta ratio in adult erythroid colonies. These results demonstrate that a variety of cell lines produce factors that stimulate the production of HbF in vitro. The genes of such factors could be isolated by expression cloning of cDNA from cell lines using the Xenopus oocyte system.
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PMID:Cell lines produce factors that induce fetal hemoglobin in human BFUe-derived colonies. 138 95

The incidence of leukemia is higher in children with Down syndrome (DS) than in normals. In approximately 50% of cases the type of leukemia is acute megakaryoblastic leukemia (AMKL) and it occurs during the first 4 years of life. The leukemic cell also has features of erythroid progenitors and therefore appears to be a precursor cell with biphenotypic properties. In addition, newborns with DS frequently develop transient leukemia (TL), which is characterized by the presence of megakaryoblasts in the blood which disappear during the first 1-3 months of life. The incidence of this disorder is unknown although preliminary studies suggest that megakaryoblasts may be found frequently in the blood of DS newborns. TL does not occur in normal newborn infants. Although TL disappears spontaneously, many of these children will develop AMKL at 1-4 years of age. Recent surveys suggest that 20-30% of newborns with TL will develop AMKL. Preliminary evidence suggests that TL is a clonal proliferation, can be fatal, and may occur in a specific subgroup of DS children. The observations in this report are drawn from our own experience, reports in the literature, and data accumulated in the Canadian Down Syndrome Leukemia Registry.
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PMID:Leukemia in Down syndrome: a review. 138 43

We have compared the expression of the ras protooncogene family (H-, K-, and N-ras) in leukemia cell differentiation utilizing as a model K562 and HEL erythroleukemia cells treated either with 1-beta-arabinofuranosylcytosine or 12-O-tetradecanoylphorbol-13-acetate (TPA). 1-beta-D-Arabinofuranosylcytosine induced terminal erythroid differentiation of K562 cells, while TPA induced myeloid differentiation of K562 and HEL cells, resulting in myelomonocytic-like cells expressing macrophagic and megakaryocytic markers. H-ras mRNA levels showed a dramatic decrease in K562 cells subjected to erythroid and myelomonocytic differentiation. The same result was found at the protein level for p21H-ras. Expression of K-ras and N-ras in K562 cells also decreased with differentiation, although significant mRNA levels remained despite cessation of cell proliferation. The decrease in K-ras expression was greater for TPA-treated cells than for 1-beta-arabinofuranosylcytosine-treated cells. TPA-induced myelomonocytic differentiation in HEL cells also resulted in a dramatic down-regulation of H-ras mRNA levels. Thus, by using a leukemia cell line able to differentiate along two different lineages, our results reveal a lineage-specific modulation of ras gene family expression.
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PMID:Differential expression of ras protooncogenes during in vitro differentiation of human erythroleukemia cells. 139 24

A 63-year-old man was admitted because of anemia and thrombocytopenia. The bone marrow was hypercellular with 66.6% erythroblasts with dysplasia and 19.8% blasts. Cytogenetically, MAKA (major karyotypic aberrations) containing 5q-, -7, -17, with karyotypic instability was observed. A diagnosis of erythroleukemia (FAB M6) was made. Six months later, immature neutrophils increased in the peripheral blood, and blasts and promyelocytes increased to 25.8% and 20.0% of marrow cells, respectively. Three months later, blasts asts increased to 33.0% in the peripheral blood. They were ultrastructually positive for platelet peroxidase. Phenotypically, 69% and 63% of blasts were positive for CD41b (GPIIb/IIIa) and CD42a (GPIb), respectively. Bone marrow biopsy showed marked proliferation of blasts and dysplastic megakaryocytes accompanied by reticulin fibrosis. These findings suggested evolution to megakaryoblastic leukemia (FAB M7). In most cases, M6 defined by the FAB criteria is stem cell disorder with multilineage involvement and major erythroid component. M6-like features may be observed in the evolutive phase to acute leukemia from myelodysplastic syndrome (MDS).
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PMID:[Evolution to megakaryoblastic leukemia observed in myelodysplastic syndrome with erythrolekemia-like features]. 140 64

E26 is an acute avian leukemia virus that contains two nuclear oncogenes, v-myb and v-ets, and that is capable of transforming early cells of the erythroid and myeloid lineages. In another study, we have found that TPA (phorbol 12,13-dibutyrate) treatment of E26-transformants displaying an 'early erythroid' phenotype results in the production of cells with either myeloid or eosinophil characteristics. To analyze this induction in greater detail we have produced a panel of four monoclonal antibodies against E26-transformants before and after TPA-induced differentiation. Two antibodies, MEP21 and MEP26, reacted with proteins of 150 and 47-60 kDa, respectively, which are expressed on the surface of E26 progenitor cells but whose expression is extinguished following TPA-induced differentiation. A third antibody, EOS47, recognizes a 100 kDa molecule that is expressed on the surface of TPA-induced peroxidase positive cells (an enzyme that in avian species is restricted to cells of the eosinophilic lineage). MEP21, MEP26, and EOS47 do not react with lymphoid, myeloid, or more mature erythroid lineage cell lines. The fourth antibody, MEP17, recognizes a heterodimer of 140 and 150 kDa chains which is expressed at high levels by E26-transformed progenitor cells and at lower levels by TPA-induced cells. Further biochemical characterization of the MEP17 antigen revealed a structure similar to that of the leukocyte adhesion molecule VLA-4; a member of the integrin family of adhesion proteins. All four antibodies react with subpopulations of cells in the bone marrow and spleens of 1-day-old chickens. Although the MEP21 and MEP26 antibodies do not appear to react with mature cells of most hematopoietic lineages they are expressed at high levels by mature thrombocytes. In addition, MEP17 is expressed at high levels by the majority of bursal B-cells, thrombocytes, and more weakly by thymocytes. The reagents described should be useful as markers for the study of development, migration, and differentiation of normal avian hematopoietic progenitor cells and eosinophilic precursors, and for the study of retrovirus-induced neoplasia.
Leukemia 1992 Oct
PMID:Cell surface proteins of chicken hematopoietic progenitors, thrombocytes and eosinophils detected by novel monoclonal antibodies. 140 65

As an introduction to a Satellite Symposium on the utilization of recombinant human erythropoietin (rHu-EPO) in hematology (Leukemia & Lymphoma 1992; 7 (Suppl.2): 94-100) a contribution to its mechanism of action was presented, and is published here. In three patients with advanced Hodgkin's disease treated with combination chemotherapy (MOPP) incorporating vincristine, and receiving at the same time a fixed daily dose of 8000 U of rHu-EPO subcutaneously for 10 to 15 days because of myelosuppressive anemia, myeloaspirates were performed one week before and 24 hours after the administration of vincristine. A dramatic accumulation of arrested metaphases in all stages of erythroblasts was found, while there was no augmentation of granulocytic metaphases. This is a further confirmation, following a previous contribution (Marmont AM: Haematol 1991; 76, 251-255), of the demonstration in man of the combined effects of erythropoietin as an erythroid mitogen and vincristine as a mitotic blocker.
Leukemia 1992 Nov
PMID:Selective metaphasic arrest of erythroblasts by vincristine in patients receiving high doses of recombinant human erythropoietin for myelosuppressive anemia. 143 24


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