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)

The origin and morphological identity of hematopoietic progenitor cells, as well as their precursor, the pleuripotential hematopoietic stem cell (HSC), has not been established. Our studies of 2 microns sectioned undecalcified plastic-embedded bone marrow (BM) from healthy human fetuses; normal adults; patients with acute myeloblastic leukemia (AML), acute lymphoblastic leukemia (ALL), and chronic granulocytic leukemia (CGL) in various stages (chronic, accelerated, acute blastic phase, and after autografting); and patients recovering from therapy-induced marrow hypoplasia suggest that proliferative hematopoietic zones exist near the endosteum (endosteal marrow) and the vascular endothelium (capillary and sinus-lining endothelium) and a maturational zone distal to these regions. In some of these areas, morphologically recognizable hematopoietic cells were seen and interpreted as emerging and maturing in a sequential progression, suggesting an origin from the endosteal or endothelial progenitors. In other loci, early hematopoietic cells were seen in close contact with the endosteal or vascular endothelial (VE) cells. This latter relationship suggested that these areas of cellular contact were important and represented sites of cell to cell interaction that may be associated with the liberation of growth factors by endosteal and endothelial cells and their action on hematopoietic progenitor cells. Following treatment-induced hypoplasia, the endosteal and VE cells were seen to modulate, transform, and migrate into the surrounding empty and edematous marrow space as fibroblasts. Later, as hemopoietic regeneration began, clusters of regenerating hematopoietic cells were seen adjacent to bone trabecule (BT) and near the vascular endothelium. We postulate that endosteal and VE cells are the equivalent of embryonal-stage, undifferentiated mesenchyme and, under the appropriate regulatory influence, are capable of modulation and transformation (differentiation) into stromal (fibroblast-like) cells and precursors of hematopoietic cells in normal (physiologic) and stressed (pathologic) conditions. Recently, human endothelial cells have been shown to express a large number of cell surface antigens in common with hematopoietic (myeloid and lymphoid) cells. It is also possible that, in some situations, the VE cells act to establish a microenvironment and liberate growth factor(s), enabling pleuripotential and progenitor cell differentiation into mature hematopoietic cells adjacent to the vascular endothelium. Indeed, vascular endothelium has been shown to elaborate growth factors that participate in normal hematopoiesis.
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PMID:Endothelial cells and hematopoiesis: a light microscopic study of fetal, normal, and pathologic human bone marrow in plastic-embedded sections. 160 75

Nineteen of 71 (26%) cases of acute myelogenous leukemia (AML) were found to express CD7, a cell surface marker found early during T lineage differentiation. These myeloid leukemias often expressed other lymphoid markers and frequently had rearranged T-cell receptor beta and immunoglobulin heavy chain genes. We propose that in CD7+ AML, the malignant transformation occurred in a CD7+ progenitor cell. CD7+ myeloid leukemic precursors may be capable of limited differentiation with loss of CD7 during the initial phase of the disease, but this capacity may diminish during the course of treatment such that CD7 expression persists.
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PMID:CD7+ acute non-lymphocytic leukemia: evidence for an early multipotential progenitor. 168 36

Thirty-two cases of acute myeloid leukaemia (AML) were examined for expression of terminal deoxynucleotidyl transferase (TdT) and rearrangements of the genes coding for the immunoglobulin heavy chain and the beta chain of the T cell receptor, in order to establish whether these two forms of lineage infidelity are linked. In 17 cases of AML with greater than or equal to 10% TdT+ cells, three cases showed evidence of gene rearrangement, two having clonal rearrangements in the immunoglobulin gene and one with a rearranged T cell receptor gene. Among 15 AML cases without significant numbers of TdT-positive blasts, three cases had rearrangements in both immunoglobulin and T cell receptor genes, while a fourth case had an immunoglobulin gene rearrangement. No relationship was seen between lymphoid gene rearrangements and expression of the lymphoid surface antigens CD7 and CD10. The lack of association between TdT expression and gene rearrangements does not support the concept of an orderly activation of the recombinase machinery in those cases of AML with features of early lymphoid differentiation.
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PMID:Lack of correlation between immunoglobulin and T cell receptor gene rearrangements and TdT expression in acute myeloid leukaemia. 168 38

Acute mixed lineage leukemias (MLL) are a heterogeneous group of acute leukemias that express morphologic and/or immunophenotypic features of more than one hematopoietic cell line. The ontogenetic significance of this mixed lineage expression is unclear. We therefore studied the conviction of the lineage commitment in a group of MLL by examining the in-vitro response of five CD2+ (E-rosette receptor) acute myelogenous leukemia (AML) to a panel of proliferation and differentiation-inducing agents. Three of the five CD2+ AML were TdT-positive. Antigen receptor gene studies revealed no rearrangements at either the T beta or immunoglobulin heavy chain gene loci in any case. When blast-enriched cell populations were placed in short term suspension cultures with PHA, IL-2, PHA + IL-2, GM-CSF or TPA, three of the leukemias responded in a similar fashion while the remaining two cases showed no response. In the three MLL that responded to the in-vitro culture manipulations, features indicative of differentiation along the monocytic lineage pathway were observed. This differentiation was not pronounced in the presence of the phorbol ester TPA, and was manifested by loss of CD2 and CD7 expression, continued expression of myeloid antigens, and the development by the blasts of morphologic and cytochemical characteristics of monocytic cells. None of the five MLL showed any evidence of induced maturation along the T-lymphocyte line of differentiation with any of the agents used. rGM-CSF was the only exogenously added agent to induce proliferation; the proliferative response was slight and was seen in only one of the five leukemias. Therefore, the phenotypic expression of CD2 and CD7 in blasts from MLL is not indicative of irreversible commitment to T-lymphocyte development. The in-vitro loss of T-cell antigens in concert with the development of monocytic features in three of the five CD2+ AML in this study suggests the leukemic cells were preferentially committed to a non-lymphoid lineage differentiation pathway.
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PMID:The in-vitro response of CD2-positive acute myelogenous leukemia to proliferation and differentiation inducing agents. 169 68

Immunohistochemical investigations were performed on decalcified, paraffin-embedded iliac crest trephine biopsy specimens from 30 cases of acute myeloid leukemia (AML, as defined by the FAB classification) with antibodies against B cells (L26, 4KB5, MB1, Ki-B3), T cells (UCHL1, MT1), myeloid/histiocytic cells (anti-neutrophil elastase, MAC387, anti-S-100 protein, anti-alpha 1-antichymotrypsin, DAKO-M1), natural killer/killer cells (anti-Leu-7), and megakaryocytes (anti-factor VIII-related antigen). (1) The blast cells of all the cases reacted with from at least two to at most eight different antibodies. Each antibody reacted with blast cells in a minimum of two (maximum 30) cases. (2) MT1, Ki-B3, anti-alpha 1-antichymotrypsin anti-neutrophil elastase, anti-S-100 protein, and MAC387 stained blast cells in more than 50% of the cases; MB1, L26, UCHL1, 4KB5, and DAKO-M1 in 20% to 50% of the cases; and anti-Leu-7 and anti-factor VIII-related antigen in less than 20% of the cases. (3) In the majority of cases many T lymphocytes, a small-to-moderate number of B lymphocytes, and a few Leu-7-positive lymphoid cells were intermingled with the blast cells. In some cases, especially where only a minor proportion of the blast cells was immunostained, it was nearly impossible to distinguish the lymphocytes of the tumor's stromal reaction from small blast cells. Thus, AML exhibits a heterogeneous immunophenotype in trephine biopsy specimens. Immunohistologic diagnosis of this disease in such specimens may be extremely difficult. Since staining of the blast cells with one or more of the antibodies generally used to define B cells, T cells, or their neoplastic derivatives is not uncommon, misinterpretation as non-Hodgkin's lymphoma of high-grade malignancy could easily occur. These findings also suggest that mixed-type (hybrid) acute leukemias with coexpression of myeloid and lymphoid cell markers could be more common than generally realized.
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PMID:Acute myeloid leukemia: immunohistologic findings in paraffin-embedded bone marrow biopsy specimens. 169 93

Within normal hemopoiesis, the intranuclear DNA polymerase TdT seems to be exclusively expressed by T and B lymphoid precursor cells. Double staining experiments showed that TdT can also be expressed in blast cells of certain acute myeloid leukemias. Recent reports described a very strong association between TdT expression and rearrangements of IgH and TcR genes in such AML specimens, suggesting a predominant lymphoid commitment of these TdT positive AML blasts. When submitting 24 serologically and morphologically well-characterized TdT positive AML specimens for additional genotypic analysis to determine the IgH and TcR gene configuration, we observed that only four had clonally rearranged IgH and/or TcR genes, whereas 20 had germ line configuration. This frequency is clearly lower than previously reported and not necessarily different from rearrangement frequencies reported for TdT negative AML (4-40%). It would seem to us, therefore, that the expression of TdT in otherwise well-defined AML blasts is not necessarily associated with a higher frequency of immunoglobulin and/or T cell receptor gene rearrangement.
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PMID:Terminal deoxynucleotidyl transferase and CD7 expression in acute myeloid leukemias are not associated with a high frequency of immunoglobulin and/or T cell receptor gene rearrangement. 169 41

An increasing number of acute leukemias coexpressed markers normally believed to be restricted to a single lineage have been found recently. This special subgroup of leukemias have drawn a lot of attention because of their biologic and clinical significance. In a study of 100 consecutive de novo ANLL patients diagnosed by FAB criteria, T-cell antigen CD7 was identified on the leukemic blasts of 13 patients, ten of whom had M1 subtype of leukemia, myeloblastic leukemia without maturation. All the patients showed positive staining with myeloperoxidase and expressed myeloid markers CD13 and/or CD33, but lacked CD11b, a marker of more mature myeloid cells. Combined staining with myeloperoxidase and CD7 of the cells from four patients revealed coexpression of both markers on the same cells. None of the patients expressed the two other T-cell antigens CD2 or CD5. All ten patients who had DNA analysis showed germline configuration of TCR beta and gamma chain genes. One patient had chromosomal translocation involving 11q23, t(11; 19) (q23; p13), which is the site frequently associated with both myeloid and lymphoid malignancies. The clinical implications of this subgroup of patients need further study on more patients, and need longer follow-up.
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PMID:A subset of acute nonlymphocytic leukemia with expression of surface antigen CD7--morphologic, cytochemical, immunocytochemical and T cell receptor gene analysis on 13 patients. 169 99

A new recurring chromosome abnormality was identified in 8 of 621 consecutive successfully karyotyped adults with de novo acute leukemia. These eight patients had trisomy 13 as the sole cytogenetic abnormality. On central morphologic review, five cases were classified as subtypes of acute myeloid leukemia, one as acute mixed lymphoid and myeloid leukemia, one as acute lymphoid leukemia, and one as acute undifferentiated leukemia. Blasts of all eight cases expressed one or more myeloid differentiation antigens. Three also expressed T-lineage-associated antigens; however, none of these had rearrangement of the T-cell receptor beta, gamma, or delta genes. Four of six cases tested were TdT positive. All eight patients with trisomy 13 were treated with intensive induction chemotherapy; only three entered a short-lived complete remission. Survival of patients with trisomy 13 ranged from 0.5 to 14.7 months, and was significantly shorter than that of the remaining patients (median 9.5 v 16.2 months, P = .007). We conclude that trisomy 13 is a rare, recurring clonal chromosome abnormality in acute leukemia associated with a poor prognosis. Malignant transformation of an immature hematopoietic precursor cell is suggested by the expression of antigens characteristic of both the myeloid and lymphoid lineage, the high incidence of TdT positivity, and the morphologic heterogeneity in these leukemias.
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PMID:Trisomy 13: a new recurring chromosome abnormality in acute leukemia. 169 82

The levels of leukocyte alkaline phosphatase (LAP) messenger RNA (mRNA) are evaluated in B and T lymphocytes, monocytes, and polymorphonuclear cells (PMNs), and this transcript is found to be present only in PMNs. Precursors of the myelomonocytic pathway, represented by leukemic cells isolated from several cases of chronic myelogenous leukemia (CML) in its stable and blastic phase and acute myelogenous leukemia (AML), are devoid of LAP transcript. These data support the notion that LAP is a marker of the granulocyte terminal differentiation. Despite the absence of LAP mRNA in both the myeloid and the lymphoid precursors, nuclear run-on experiments show constitutive transcription of the LAP gene in leukemic cells obtained from AML, CML, as well as acute lymphoblastic leukemia (ALL) and B-cell chronic lymphocytic leukemia (B-CLL). In CML and in chronic myelo-monocytic leukemia (CMML) PMNs, granulocyte colony-stimulating factor (G-CSF) specifically accumulates LAP mRNA without showing a substantial increase in the rate of transcription of the LAP gene. Once increased by G-CSF, LAP mRNA is very stable, showing a half-life of more than 4 hours in the presence of actinomycin-D. G-CSF is suggested to play a pivotal role in the modulation of LAP transcript in PMNs.
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PMID:Expression of leukocyte alkaline phosphatase gene in normal and leukemic cells: regulation of the transcript by granulocyte colony-stimulating factor. 170 29

Although most circulating T cells in normal subjects express both CD3 and CD5 antigens on the cell surface, a small number lack the CD5 antigen. Recipients of allogeneic bone marrow transplants develop increased numbers of CD3+ CD5- cells, particularly those who develop graft versus host disease (GVHD). This CD3+ CD5- population may rise transiently in patients who have received an autologous bone marrow transplant (BMT) and in patients following completion of intensive chemotherapy for acute myeloid leukaemia (AML). These findings suggest that these CD3+ CD5- cells are a normal component of the regenerating lymphoid system after BMT or chemotherapy.
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PMID:Recovery of CD3+ and CD5- lymphocyte subpopulation after autologous bone marrow transplantation and chemotherapy. 170 18


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