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)

We retrospectively studied the factors affecting the rate of hematopoietic reconstitution (HR) in 118 patients with hematological malignancies who underwent peripheral blood progenitor cell (PBPC) transplantation at a single institution. The patients received a median number of 6.6 x 10(8) nucleated cells/kg corresponding to 9.5 x 10(4) (0.5-578) CFU-GM/kg and 6.8 x 10(6) (0.2-161) CD34-positive cells/kg. The median number of days to reach 500 polymorphonuclear cells/mm3 and 50,000 platelets/mm3 was 12.5 (6-93) and 14.5 (6-440) days, respectively. No patient died from infection during the aplastic phase. By multivariate analysis, we found that the dose of CFU-GM infused was the only factor that significantly affects the HR rate (p < 0.0001). Moreover, patients with acute myelogenous leukemia or those transplanted after busulfan or total-body irradiation conditioning regimens had a slower engraftment (p < 0.08). These results could lead to identifying patients who need growth factors posttransplantation and/or the reinfusion of "back-up" marrow together with PBPC.
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PMID:Peripheral blood progenitor cell transplantation in 118 patients with hematological malignancies: analysis of factors affecting the rate of engraftment. 753 Jan 33

Immunological analysis of bone marrow cells in myelodysplasia using immunofluorescence did not allow accurate morphological identification of blast cells. However, improvement of the immunoperoxidase technique allows one to realize the diagnostic potential of immunocytochemistry. CD34 immunotyping of blasts in normal human bone marrow showed 0.8 +/- 0.4% CD34 positive blasts and these cells had the morphology of type 1 blasts. The increase of bone marrow blasts in RAEB patients is related to CD34 negative type II and III blasts. A clone of undifferentiated CD34 positive blasts is characteristic of RAEB-T and acute myeloid leukaemia evolving from myelodysplasia. The detection of CD34 positive bone marrow blasts allows a better discrimination between RAEB and RAEB-T.
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PMID:CD34 immunophenotyping of blasts in myelodysplasia. 753 58

In the present study, seven normal human bone marrow samples from healthy volunteers have been analysed in order to investigate the immunophenotypic characteristics of the normal CD117+ cells and their utility for the detection of minimal residual disease in 71 acute myeloid leukaemia patients. Our results show that most of normal BM CD117+ cells coexpress the HLADR and the myeloid associated CD33 antigen. In addition, almost half of CD117+ cells are CD34+, these cells displaying a different FSC/SSC distribution when compared to the CD117+/CD34- cells. No CD117+/CD15+ and CD117+/CD10+ cells were detected and very few CD117+ cells (< 1 x 10(-3) expressing the HLADR-/CD34-, CD33+/HLADR- and CD34+/HLADR- phenotypes were found to be present in normal BM. In contrast, from the 71 AML patients analysed, 34 had CD117+/CD15+ blast cells and eight had the CD117+ phenotypes detected at low frequencies (< 1 x 10(-3)) in normal BM. In summary, the present study shows that the use of the CD117 antigen in different monoclonal antibodies combinations may be of great help for the detection of minimal residual disease in a high proportion of AML cases, especially in those patients displaying the CD117+/CD15+ phenotype, because cells coexpressing both antigens in normal BM, if present, are at very low frequencies.
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PMID:Immunophenotype of c-kit cells in normal human bone marrow: implications for the detection of minimal residual disease in AML. 753 85

Since in AML differentiation is abnormal but not absent, a hierarchy of stem cells, progenitor cells and more differentiated cells is postulated. The leukemic stem cell might also be characterized by the expression of CD34 and the absence of differentiation markers. Bone marrow samples of 33 AML patients, including 10 patients both at presentation and after relapse, were double labeled for CD34 and CD33. In 14/33 AML less than 1% of the labeled cells were found in the CD34+/33- fraction. After relapse a certain shift towards a more primitive phenotype was observed, but in 4/5 relapsed AML the CD34+/33- fraction remained below 1%. Single cells from the different subfractions were cultured and showed heterogeneous cluster and colony growth in both the CD34-/33+ and CD34+/33+ fraction. More colonies were observed in the CD34+/33- fraction. In AML with a more 'mature' phenotype (low number of CD34+/CD33- cells), highly proliferative myeloid, erythroid and mixed colonies could be cloned exclusively from this small CD34+/33- fraction. In five patients with numerical chromosomal abnormalities all these highly proliferative colonies appeared disomic using in situ hybridization (ISH) with centromeric probes. Based on these data we conclude that the CD34+/33- cell fraction in AML with a more mature immunophenotype (small fraction of cells CD34+/33-) comprise residual normal progenitors, while no primitive leukemic progenitors could be identified.
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PMID:Residual normal, highly proliferative progenitors can be isolated from the CD34+/33- fraction of AML with a more differentiated phenotype (CD33+). 753 67

To evaluate the clinical relevance of multidrug resistance (MDR) phenotype, the intracellular daunorubicin accumulation (IDA) and P-glycoprotein (P-gp) expression were investigated in 87 adult patients with acute leukemia: 69 patients with de novo acute myeloid leukemia (AML), 10 with AML at relapse, and eight with secondary leukemia to myelodysplastic syndromes (MDS-AML). IDA and P-gp expression were determined by double-labeling flow cytometry analysis. Of 87 patients, 36 expressed P-gp (41%). P-gp expression was more frequently observed in AML at relapse and MDS-AML as compared with de novo AML (P = .0001). P-gp expression was significantly associated with CD34 expression (P = .0003) and chromosome 7 abnormalities (P = .027). A significantly reduced IDA was observed in P-gp+ as compared with P-gp- patients (P = .0007). Of the 87 patients, 51 achieved complete remission (CR). A reduced IDA was observed in patients in failure as compared with patients in CR (22% +/- 17% v 42% +/- 21%; P = 10(-4). Twelve of 36 P-gp+ patients as compared with 40 of 51 P-gp- patients achieved CR (33% v 78%; P = 10(-4). The prognostic value of IDA and P-gp expression was confirmed in multivariate analysis. These data suggest that the determination of IDA and P-gp expression may be useful in designing therapy for patients with AML.
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PMID:Predictive value for treatment outcome in acute myeloid leukemia of cellular daunorubicin accumulation and P-glycoprotein expression simultaneously determined by flow cytometry. 753 92

The expression of c-kit receptor (c-kit R; CD117) and CD34 was examined in acute myeloid leukemia (AML), acute lymphoid leukemia (ALL), chronic myeloid leukemia (CML) in blastic transformation (BT), and myelofibrosis (MF) in myeloid BT. In myeloid leukemia including AML, CML-myeloid BT and MF-myeloid BT, both c-kit R and CD34 were expressed synchronously, while in lymphoid leukemia including ALL and CML-lymphoid BT, only CD34 was highly expressed. A close correlation between c-kit R and CD33 expression and an inverse correlation between c-kit R and CD19 expression were observed when all of the myeloid plus lymphoid leukemia cells were analysed. There was a close correlation between c-kit R and CD34 expression in the myeloid leukemia cells. c-kit R expression may be associated with myeloid phenotypes of leukemic cells and may be useful for the diagnosis of myeloid leukemia. The literature of c-kit R expression in leukemic cells is reviewed here and the comparison of c-kit R and CD34 expression in normal hematopoietic progenitor cells with those on the leukemic counterparts was discussed.
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PMID:Expression of c-kit receptor (CD117) and CD34 in leukemic cells. 753 10

Although it has been shown that the percentage of bone marrow blasts in myelodysplastic syndrome (MDS) constitute the only independent determinant of survival and progression to acute leukemia, the great variability in survival among patients with MDS of similar percentage of blasts has prompted us to investigate new objective, independent prognostic parameters for the selection of high-risk patients. It was suggested that CD34 antigen expression adversely affected the prognosis of acute myelogenous leukemia. However, no study has been published so far on clinical and prognostic significance of CD34 antigen expression in MDS. Bone marrow biopsies from 58 patients diagnosed as primary MDS were studied using QBEND/10, a monoclonal antibody which recognized the human progenitor CD34 antigen on routine aldehyde-fixed, paraffin-embedded samples. The high percentage of CD34-positive cells (above 3% of total bone marrow nucleated cells) was predominantly observed in cases with RAEB-T, CMML, and to a lesser degree in RAEB. But neither age, hemograms, bone marrow findings including percentage of blasts, ALIP, nor leukemic transformation correlated with the percentage of CD34-positive cells. The median actuarial survival time in the high positive group was significantly shorter (12.0 months) than that of the low group (30.0 months; p = 0.028). The high CD34 aggregate (> or = 3) was selectively found in cases with RAEB, RAEB-T, and CMML. The percentage of bone marrow blasts (p = 0.007) and ALIP (p = 0.030) significantly correlated with number of CD34 aggregates.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:CD34 immunohistochemical staining of bone marrow biopsies in myelodysplastic syndromes. 753 31

Stem cell factor (SCF), a c-kit ligand, has a preferential effect on the proliferation of several classes of immature hematopoietic progenitor cells in combination with GM-CSF or IL-3. To analyze the costimulatory role of SCF in leukemic growth, we investigated the effect of SCF in the presence of GM-CSF and/or IL-3 on isolated CD34-positive (CD34+) leukemic blasts from 15 patients with acute myelogenous leukemia (AML). Cultures of CD34+ cells from normal bone marrow were used as controls. When the proliferation of CD34+ AML blasts in the presence of GM-CSF and/or IL-3 were evaluated in vitro for the effects of SCF, two patterns emerged. In one pattern, CD34+ AML blasts responded with a significant increase in DNA synthesis and/or colony formation when SCF was used with GM-CSF and/or IL-3 relative to the growth with SCF alone; This result is consistent with those CD34+ bone marrow cells from normal donors. Six patients (40%) were included in this category. The addition of SCF as a single factor resulted in colony formation in all six of these cases. In the other pattern, nine of the patients (60%) had CD34+ leukemic cells whose growth with SCF plus either GM-CSF, IL-3, or GM-CSF+IL-3, was not significantly different from the growth noted in the presence of SCF alone. Among them seven cases that did not form colonies in response to SCF alone, and one case showing autocrine, background growth were included. In the six cases in which the costimulating effects of SCF were documented, CD34+ c-kit+ blasts comprised 50.5 +/- 18.7% of the CD34+ leukemic blasts-higher than 21.8 +/- 19.4% of cases in which the costimulating effect of SCF was not documented. In the cases showing high c-kit antigen expression (> or = 40%), SCF had a costimulatory effect in 71% (5/7) of the patients. In conclusion, our data indicate that CD34+ leukemic blasts from a good proportion of patients with AML did not respond to the costimulating effects of SCF in the presence of GM-CSF adn/or IL-3, in contrast to those CD34+ bone marrow cells from normal donors. The possible use of SCF for acute leukemia must await further cytogenetic and molecular studies, which should clarify the preferential costimulating role of SCF in normal hematopoiesis.
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PMID:Differential responses of CD34-positive acute myelogenous leukemic blasts to the costimulating effects of stem cell factor with GM-CSF and/or IL-3. 753 32

CD34 is expressed on human and murine hematopoietic stem and progenitor cells and its clinical usefulness for isolation of stem/progenitor cells has been well established. Although expression of CD34 is regulated in a developmental stage-specific manner, the function of CD34 is not known. Recently we have shown that both a full-length and truncated form of CD34 protein is expressed by hematopoietic cells (Blood 84:691, 1994). To test whether failure to suppress either form of CD34 could affect terminal myeloid differentiation, we constitutively expressed these CD34 proteins in murine M1 myeloid leukemia cells, which can be terminally differentiated to macrophages by treatment with interleukin-6 of leukemia inhibitory factor. Surprisingly our results show that forced expression of the full-length but not the truncated form of CD34 impedes terminal differentiation by these agents. Because the difference between the two forms of CD34 protein resides in the length of their respective cytoplasmic tail domains, our findings strongly suggest that the cytoplasmic domain region of full-length CD34 is responsible for the observed maturation arrest phenotype. These findings suggest a potential negative regulatory role for full-length CD34 in hematopoietic cell differentiation and may explain, at least in part, the block in maturation observed in CD34+ acute myeloid leukemia.
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PMID:Full-length but not truncated CD34 inhibits hematopoietic cell differentiation of M1 cells. 753 13

The c-mpl proto-oncogene which encodes a member of the hematopoietic cytokine receptor superfamily has been recently shown to be the receptor for thrombopoietin (TPO), which stimulates megakaryocyte progenitor expansion and differentiation. We studied c-mpl expression by Northern blot analysis, in a large series of 58 MDS. No expression was found in 14 patients with refractory anemia (RA) or with refractory anemia with ring sideroblasts (RARS). In contrast 11/26 (42%) patients with refractory anemia with excess of blasts (RAEB), or with RAEB in transformation (RAEBt), and 8/18 (44%) patients with chronic myelomonocytic leukemia (CMML) expressed c-mpl. In CMML patients, no correlation was found between c-mpl expression and any prognostic factor tested, nor with the course of the disease. In contrast, in RAEB and RAEBt, expression of c-mpl was correlated with high Bournemouth scoring (P < 0.005) and poor survival (P = 0.02) due to leukemic transformation. Forty-five per cent (5/11) of the c-mpl positive patients evolved towards AML with a mean follow-up of 10.5 months, while 13% (2/15) of the c-mpl negative patients developed a secondary leukemia, with a mean follow-up of 21.1 months. Moreover, in RAEB and RAEBt, a significant correlation was observed between c-mpl, CD34, megakaryocyte glycoprotein IIb (GPIIb) expression, and the presence of dysmegakaryopoiesis. These results indicate that patients with RAEB and RAEBt, with high expression of the c-mpl, CD34, and GPIIb genes, may identify a subgroup of patients with particularly poor prognosis, due to an increased risk of secondary leukemia. More aggressive therapy could be justified in these patients.
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PMID:Prognostic value of c-mpl expression in myelodysplastic syndromes. 753 13


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