Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0023418 (leukemia)
 93,477 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

We assessed the number of Langerhans cells (LC) before and after bone marrow transplantation (BMT) in 27 patients in order to study the fate and behavior of these dendritic antigen-presenting cells following allogeneic BMT. LC were identified using monoclonal antibody OKT6 on skin biopsies performed on days - 10, 0, 11, 25, 39, 120, and 365. In a control group composed of 15 healthy adults aged 20-37 yr, the mean number of LC (+/- SEM) was 25.6 +/- 1.17/0.1 sq mm of epidermal surface. Our study shows that pretransplant, the number of LC in patients with aplastic anemia or leukemia was lower than that of controls. The finding of low numbers of LC in patients with untreated aplastic anemia is suggestive of a medullary origin of LC in man. Moreover, during the early posttransplant period, nearly all patients present a severe deficit in LC. This deficit may delay the maturation of their immune system. The number of LC reaches nearly normal levels 4-12 mo after BMT. Finally, we have noted a significant impairment of LC reconstitution in patients with acute graft-versus-host disease (GVHD), providing evidence that this defect may be an important mechanism involved in acute GVHD-related immunodeficiency.
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PMID:Study of Langerhans cells after allogeneic bone marrow transplantation. 636 51

Monoclonal antibodies generated against normal and leukemic human leukocytes were tested for their differential reactivity with leukemia and lymphoma cell lines as well as with circulating lymphoid and myeloid leukemic cells by means of immuno-scanning electron microscopy (immuno-SEM). Anti-T (OKT3), anti-mu-chain, anti-CALLA (J5), anti-BA-1, anti-BA-2, and anti-nonlymphoid (Mol) monoclonal antibodies were covalently conjugated to polystyrene latex microspheres (immunolatex), using a two-step glutaraldehyde reaction, and subsequently incubated with the various cell types. Cultured B-type Burkitt lymphoma cells (Daudi) and chronic lymphocytic leukemia (CLL) cells displayed extensive labeling with monoclonal anti-mu, anti-B1, and anti-BA-1 immunolatex conjugates, while cultured malignant T cells (HD-Mar) showed positive labeling with OKT3 immunolatex alone. Cultured myelomonocytic cells (GDM-1) and cells obtained from patients with acute myeloblastic (AML) and monoblastic leukemia (AMoL) labeled only with anti-Mol immunolatex, while cultured promyelocytic cells (HL-60) displayed far less labeling with this conjugate. Common-type acute lymphoblastic leukemia (C/ALL) cells were labeled predominantly with the J5 (anti-CALLA) and anti-BA-2 immunolatex conjugates. Evidence is presented indicating that immuno-SEM employing monoclonal antibodies is a reproducible technique which may be used in the study of leukocyte maturation and may provide additional information in the classification of poorly differentiated leukemias.
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PMID:Utilization of monoclonal antibodies and immuno-scanning electron microscopy for the positive identification of human leukemic cells. 658 Nov 72

The ultrastructural features of the monocytic blast cells of 37 patients with M4 and M5 types of leukemia were examined with transmission (TEM) and scanning (SEM) electron microscopes. The cells showed a large variety in nuclear size and shape, dependent on the stage of cell differentiation. Nuclear pockets, appendices and bridges were observed. The cytoplasm contained perinuclearly located fibrils, occasionally elongated mitochondria and Auer bodies. The surface ultrastructure of the cells was similar to that of healthy monocytes, but often numerous blebs were observed.
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PMID:Transmission and scanning electron microscopy findings in 37 patients with monocytic leukemia. 658 72

We investigated the requirement for intimate contact between bone marrow stroma and B lymphoblasts from normal donors and children with leukemia. By scanning electron microscopy, both normal and leukemic cells seeded onto stroma were surrounded by folds of stromal cells or were linked to the stroma by fine tendrils and uropods. Separation of normal B progenitors from stroma by use of microporous membranes led to significantly lower cell recoveries compared with results when contact was unimpeded. For instance, 22.5% +/- 1.8% (mean +/- SEM) of CD19+, CD34+ cells (most immature subset) were recovered after a 7-day culture directly on stroma, compared with 5.2% +/- 0.7% after growth on membranes (P < .001 by Student's t test). In 6 of 11 cases of B-lineage acute lymphoblastic leukemia, separation of progenitors from stroma resulted in apoptosis and a greater than 60% reduction in cell recovery. In the remaining 5 cases, however, this effect was much less pronounced, with reductions in cell recoveries ranging from 48.5% to less than 1% (median, 39.0%) of control values. Inhibition of very late antigen-4, a surface molecule critical for adhesion of B lymphoblasts to stroma, was associated with a greater loss of normal CD34+ B progenitors compared with that for equivalent leukemic cells. These results establish direct contact with stroma as a survival requirement of normal B lymphoblasts and show marked heterogeneity in stromal dependency among B-lineage leukemic cells.
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PMID:Adhesion-dependent survival of normal and leukemic human B lymphoblasts on bone marrow stromal cells. 750 32

The effects of Na+ and Ca2+ ions on histamine release from human basophils stimulated by anti-IgE, N-formyl-methionyl-leucyl-phenylalanine (FMLP), 4 beta-phorbol 12-myristate 13-acetate (PMA) and Ca2+ ionophore A23187 were evaluated. Isosmotic replacement of Na+ in the extracellular medium with the nonpermeant Na+ analogue choline+ or with glucose led to a significant increase in anti-IgE- (1/5000: 43.7 +/- 7.3% in high Na+ vs 68.9 +/- 7.3% in low Na+, mean +/- SEM, n = 8, P < 0.001), FMLP- (1 microM: 37.9 +/- 2.3% vs 49.5 +/- 4.3%, n = 8, P < 0.01) and PMA-(160 nM: 12.7 +/- 0.9% vs 27.3 +/- 4.3%, n = 8, P < 0.05) induced histamine release, whereas A23187-induced histamine release was reduced (1 microM: 90.4 +/- 2.4% vs 45.4 +/- 3.4%, n = 8, P < 0.0001). The progressive increase in extracellular Na+ concentration was accompanied by a decrease of basophil response to anti-IgE, FMLP and PMA; in contrast, A23187-induced histamine release was up-regulated by Na+. The Na+/H+ exchanger monensin, in the concentration range of 10(-8)-10(-4) M, exerted a dose-dependent inhibitory effect on anti-IgE-, FMLP- and PMA-induced histamine release, but not on A23187-induced histamine release. Extracellular Ca2+ up-regulated the histamine release induced by all the above stimuli. Removal of extracellular Na+ lowered the requirement of extracellular Ca2+ for anti-IgE, FMLP- and PMA-induced histamine release. In contrast with previous observations showing that Na+ supports histamine release from rat peritoneal mast cells and rat basophilic leukaemia cells, these results indicate that Na+ strongly inhibits histamine release from human basophils stimulated by anti-IgE, FMLP and PMA, whereas it enhances Ca2+ ionophore A23187-induced histamine release. The effects of Na+, which are probably related to modulation of membrane potential and/or intracellular pH, vary depending on the cell type and the stimulus employed for cell activation.
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PMID:Ionic regulation of human basophil releasability. III. Effects of Na+ and Ca2+ on histamine release induced by different stimuli. 753 2

Acute leukaemia of infancy is associated with abnormalities at chromosome band 11q23, and has a poor prognosis. The gene involved. Mixed Lineage Leukaemia (MLL), has been identified and has the characteristics of a transcription factor. The BCL-2 gene responsible for blocking of programmed cell death is highly expressed in a number of haematological malignancies, both with and without the t(14;18) translocation. Those without the translocation include acute lymphoblastic leukaemia (ALL), acute myeloid leukaemia (AML) and chronic lymphocytic leukaemia (CLL). In these diseases the BCL-2 protein is implicated in drug resistance to apoptosis-inducing chemotherapeutic agents. High BCL-2 expression is also associated with autonomous growth of leukaemic blasts in culture and predicts a poor prognosis. The SEM cell line, established using blood lymphoblasts from a 5-year-old girl in first relapse with t(4;11) ALL, expresses lymphoid (CD19) and myeloid (CD13) cell surface markers. In cell culture, a subpopulation of cells (< 30%) express the BCL-2 protein. A reproducible model of true biphenotypic leukaemia in the SCID mouse has been established using the SEM-K2 cell line (a subclone of the SEM cell line). Between 5 and 50 million cells injected intravenously (i.v.) produce complete replacement of the murine bone marrow by day 30, associated with blood lymphoblastosis and infiltration of the spleen. No tumour masses were seen. Fluorescence in situ hybridization (FISH) analysis of the cell line and blood from the SCID-human (SCID-hu) chimaera has confirmed the presence of the t(4;11). Reverse transcriptional-polymerase chain reaction (RT-PCR) reveals that the breakpoint lies between exons 7 and 8 of the MLL-1 gene on chromosome 11 (the main breakpoint region). A further translocation, t(7;13), has been identified. Fluorescent antibody cell sorter (FACS) analysis of tumour material recovered from the SCID-hu model confirms expression of CD19 and CD13 identical to that of the cell line. In addition, BCL-2 expression in SCID-hu marrow is now seen in the majority of tumour cells. BCL-2 expression appears to confer a survival advantage to the blast cells in vivo. This reproducible model of biphenotypic leukaemia suggests that BCL-2 expression may play a role in leukaemogenesis. The model is suitable for the investigation of gene-targeted therapy, including antisense oligonucleotides, directed towards the MLL and BCL-2 genes.
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PMID:BCL-2 expression by leukaemic blasts in a SCID mouse model of biphenotypic leukaemia associated with the t(4;11)(q21;q23) translocation. 766 64

Occupational exposure to benzene is known to cause leukemia, but the mechanism remains unclear. Unlike most other carcinogens, benzene and its metabolites are weakly or nonmutagenic in most simple gene mutation assays. Benzene and its metabolites do, however, produce chromosomal damage in a variety of systems. Here, we have used the glycophorin A (GPA) gene loss mutation assay to evaluate the nature of DNA damage produced by benzene in 24 workers heavily exposed to benzene and 23 matched control individuals in Shanghai, China. The GPA assay identifies stem cell or precursor erythroid cell mutations expressed in peripheral erythrocytes of MN-heterozygous subjects, distinguishing the NN and N phi mutant variants. A significant increase in the NN GPA variant cell frequency (Vf) was found in benzene-exposed workers as compared with unexposed control individuals (mean +/- SEM, 13.9 +/- 1.7 per million cells vs. 7.4 +/- 1.1 per million cells in control individuals; P = 0.0002). In contrast, no significant difference existed between the two groups for the N phi Vf (9.1 +/- 0.9 vs. 8.8 +/- 1.8 per million cells; P = 0.21). Further, lifetime cumulative occupational exposure to benzene was associated with the NN Vf (P = 0.005) but not with the N phi Vf (P = 0.31), suggesting that NN mutations occur in longer-lived bone marrow stem cells. NN variants result from loss of the GPA M allele and duplication of the N allele, presumably through recombination mechanisms, whereas NO variants arise from gene inactivation, presumably due to point mutations and deletions. Thus, these results suggest that benzene produces gene-duplicating mutations but does not produce gene-inactivating mutations at the GPA locus in bone marrow cells of humans exposed to high benzene levels. This finding is consistent with data on the genetic toxicology of benzene and its metabolites and adds further weight to the hypothesis that chromosome damage and mitotic recombination are important in benzene-induced leukemia.
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PMID:Benzene induces gene-duplicating but not gene-inactivating mutations at the glycophorin A locus in exposed humans. 773 33

The chromosomal breakpoint and fusion transcripts of the pre-B-leukaemia-derived SEM cell line carrying a reciprocal t(4;11)(q21;q23) translocation were analysed. The breakpoint from derivative chromosome der4 was cloned and sequenced. The crossover site was localized in intron 7 of the ALL-1 gene on chromosome 11q23 and in a large intron of the AF-4 (FEL) gene. RNA transcripts from both wild-type genes and both hybrid genes were detected by reverse transcriptase polymerase chain reaction (RT-PCR) assays. In addition, alternatively spliced mRNA species derived from the der4 chromosome were found. They were generated by using the exon 5' of the breakpoint on der4 as a common splice donor site and the 5' boundaries of exons 8 or 9 of the ALL-1 gene as alternative splice acceptor sites. The hypothesis is proposed that selective pressure operators to maintain the presence of both derivative chromosomes as important elements in the leukaemogenic process.
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PMID:Molecular analysis of the chromosomal breakpoint and fusion transcripts in the acute lymphoblastic SEM cell line with chromosomal translocation t(4;11). 779 49

The aims of this study were: to quantify immunoreactive tumour necrosis factor alpha (TNF-alpha) concentrations in maternal plasma and amniotic fluid obtained from women during pregnancy and labour, both at term and preterm; and to establish the effects of bacterial endotoxin and cytokines on the in vitro release of TNF-alpha from intrauterine tissues. Maternal plasma TNF-alpha concentrations did not change during pregnancy (457.2 +/- 102.9 ng/l, mean +/- SEM, N = 52) or at the time of labour (543.5 +/- 138.6 ng/l, N = 43). In contrast, amniotic fluid TNF-alpha concentrations increased significantly (p < 0.05) during pregnancy (early pregnancy, EP, 93.0 +/- 24.8 ng/l, N = 7; preterm not-in-labour, PNIL, 186.8 +/- 42.9 ng/l, N = 16; term not-in-labour. TNIL, 499.7 +/- 150.9 ng/l, N = 13) and in association with preterm labour (preterm in-labour, PIL, 958.7 +/- 575.6 ng/l, N = 5 vs PNIL, 186.8 +/- 42.9 ng/l, N = 16). Choriodecidual and placental explants (N = 3) maintained in in vitro culture released TNF-alpha. Furthermore, the release of TNF-alpha was increased significantly (p < 0.05) by bacterial endotoxin (lipopolysaccharide, 10 ng/l-10 mg/l) but was not affected by the following cytokines at the indicated doses: interleukin-1 alpha (0.28 nmol/l), interleukin-6 (12.5 nmol/l), granulocyte colony-stimulating factor (2.5 nmol/l), granulocyte-macrophage colony-stimulating factor (35 nmol/l), macrophage colony-stimulating factor (1.2 nmol/l), leukaemia inhibitory factor (0.45 nmol/l) and transforming growth factor-beta (0.4 nmol/l).(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Tumour necrosis factor alpha during human pregnancy and labour: maternal plasma and amniotic fluid concentrations and release from intrauterine tissues. 780 44

Having noted symptomatic osteoporotic vertebral collapse in young adult survivors of childhood malignancy, bone mineral density (BMD) was examined at three sites by dual-energy X-ray absorptiometry in 64 patients treated in childhood for intracranial malignancy (group 1; n = 21) or acute leukaemia (group 2; n = 43). Patients in group 1 were selected for growth hormone deficiency (GHD) by auxological and biochemical criteria before the end of puberty (Tanner stage V). Seven patients (six men; mean (+/- SEM) age at study, 28.0 +/- 2.9 years; mean age at diagnosis, 8.7 +/- 1.5 years) in this group had been treated with human pituitary growth hormone (GH) for 1-12 years; and 14 patients (nine men; mean age at study, 26.8 +/- 1.0 years; mean age at diagnosis, 10.7 +/- 1.4 years) had not received GH. Bone densities in group 1 were normal in the GH-treated patients at the femoral neck (98.4 +/- 3.8% of control), lumbar spine (100.4 +/- 6.1% of control) and Ward's triangle (101.0 +/- 6.1% of control) but markedly reduced in the untreated group (femoral neck, 81.2 +/- 2.6% of control (p = 0.002); lumbar spine, 79.1 +/- 4.1% of control (p = 0.04); Ward's triangle, 80.1 +/- 3.6% of control (p = 0.01)). The majority of patients in group 2 had been treated for acute lymphoblastic leukaemia (ALL) and were in three subgroups.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Bone mineralization after treatment of growth hormone deficiency in survivors of childhood malignancy. 794 25


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