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Query: UMLS:C0023473 (chronic myeloid leukemia)
 18,916 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Six cases of Ph1 chromosome negative chronic myelocytic leukemia (CML) were studied. In five cases, the BCR gene configuration was analyzed with a probe covering the major breakpoint cluster region (M-bcr). No M-bcr rearrangement was detected in two cases. On the contrary, the BCR gene was found rearranged in three other patients. The breakpoints of the chromosome 22 were localized within the M-bcr in two cases and in a region upstream the M-bcr in the remaining case. These data suggest that Ph1 negative CML can be divided into two groups according to the BCR gene stattus. The clinical characteristics and pathogenesis of these two groups may be different.
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PMID:[Molecular study of Ph1 chromosome negative chronic myelocytic leukemia]. 166 Jul 59

We have developed a polymerase chain reaction (PCR) assay for detection of integrated retroviral transgenomes containing the neo G418 resistance gene in colonies (40 cells or more) grown in G418 selection after exposure to the neo-positive retrovirus LNL6. This assay also provides for simultaneous characterization of these colonies as belonging to a chronic myelogenous leukemic (bcr-abl positive) or nonleukemic population (bcr-abl negative). Using these techniques, we assessed transduction of the LNL6 retrovirus into the normal and leukemic cells of a blast-crisis chronic myelogenous leukemia (CML) patient. This work was designed to support the use of the LNL6 retroviral marker to help identify the origin of relapse after autologous marrow infusion. The data from these experiments show that the majority of CML blast crisis cells that, following exposure to the LNL6 virus, produce colonies under rigorous G418 selection are indeed transduced by the virus, as shown by the presence of the neo retroviral gene. Most of these colonies are also shown to be leukemic by PCR detection of the bcr-abl RNA. This demonstrates the feasibility of the study of CML marrow for retroviral marking. These procedures will be of use in establishing if relapse arises from leukemic blasts which contaminate purged autologous bone marrow infused following intensive therapy for leukemia.
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PMID:Molecular analysis of retroviral transduction in chronic myelogenous leukemia. 166 48

The bcr-abl RNA transcript is the molecular counterpart of the Philadelphia chromosome and is detectable by an extremely sensitive polymerase chain reaction assay in most patients with chronic myelogenous leukemia. To determine the effectiveness of ablative radiochemotherapy and bone marrow transplantation in eradicating molecular evidence of the malignant clone, we assayed for bcr-abl RNA expression in specimens from 19 patients with CML in chronic phase (CP) who have survived for at least one year post-BMT. We correlated these results with the patients' remission status based on cytogenetic analysis and BM morphology, and with evidence of mixed hematopoietic chimerism by analysis of RBC antigen and DNA restriction fragment length polymorphism patterns. Thirteen of the 19 patients had detectable bcr-abl RNA at some time following BMT. Twelve of these patients have remained in remission by morphologic and karyotypic criteria from 16.6 to 63.7 months following BMT. One of these 13 patients relapsed both by cytogenetic and clinical criteria at 28.1 months after BMT. Six of these 13 patients are still positive at the time of their most recent analysis. Only two patients have evidence for mixed chimerism of normal hematopoietic elements by either RBC antigen or DNA RFLP patterns. These results suggest that, in some patients transplanted for CML in CP, small numbers of residual leukemic cells may persist or reappear transiently without leading to clinical relapse. The definition of complete remission in CML may need to be revised in light of the enhanced ability to detect minimal residual disease by PCR technology.
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PMID:Persistence of bcr-able gene expression following bone marrow transplantation for chronic myelogenous leukemia in chronic phase. 167 85

Nine patients with chronic myelocytic leukemia (CML) and 1 patient with erythroleukemia were studied with 3'bcr and 5'bcr probes using Southern blot hybridization technique. Bcr rearrangements were detected in 8 patients with CML in the chronic phase, and bcr rearrangement was deduced to have existed in a CML patient in blastic crisis. However, no abnormal fragment was found in the patient with erythroleukemia. 3'bcr and 5'bcr probes combined with proper restriction enzymes were believed to be of great value in determining bcr rearrangements in Ph positive CML.
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PMID:BCR rearrangements in Ph positive chronic myelocytic leukemia. 168 Jun 11

Cytogenetic evaluation of patients after bone marrow transplantation (BMT) has provided a standard method of documentation of hematopoietic engraftment. More recently, recombinant DNA technology has also been applied to determine engraftment status. In order to establish the relative utility of these methods in clinical practice we have directly compared the data from cytogenetic and recombinant DNA methods, evaluating engraftment status in 68 BMT recipients. Patients were evaluated pre-transplant, 30, 60, 90, and 180 days after BMT, and yearly thereafter for 1) the presence or absence of the Y chromosome in sex-mismatched allogeneic transplant recipients, 2) the presence or absence of the Philadelphia chromosome [t(9;22)] in patients transplanted for chronic myelogenous leukemia (CML), 3) restriction fragment length polymorphism (RFLP) profiles, and/or 4) clonal rearrangement of the bcr gene. Cytogenetic examination of unstimulated bone marrow and recombinant DNA tests of nucleated peripheral blood or bone marrow cells produce qualitatively similar data in the identification of patient and donor cells and/or normal and tumor cells. Differences in the results obtained by the two analytic methods were most often due to the restricted cell populations evaluable by cytogenetic studies of PHA-stimulated peripheral blood specimens. DNA analyses could frequently be applied at earlier intervals after transplantation and, in cases of graft rejection, when cell counts were low. Although recombinant DNA methods required fewer cells and demonstrated greater sensitivity in detection of minor cell populations in the majority of instances, the cytogenetic evaluation may complement the DNA studies and allow detection of additional chromosomal anomalies.
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PMID:Comparison of molecular and cytogenetic methods in the evaluation of engraftment following allogeneic bone marrow transplantation. 168 32

Juvenile chronic myeloid leukemia (JCML) is an unusual subtype of children's leukemia, characterized by unique clinical presentation. Recent studies revealed several biological features, distinguishing from those observed in adult type chronic myeloid leukemia (ACML). The majority of ACML cases are characterized by the presence of an hybrid bcr-abl rearranged gene. In an effort to elucidate the molecular basis of this unusual leukemia we looked for bcr rearrangement in six JCML cases. No bcr rearrangement was identified in any of the analyzed samples. Together with previous studies from JCML cases, JCML has a different mechanism of leukomogenesis from ACML.
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PMID:Lack of bcr rearrangement in juvenile chronic myeloid leukemia. 168 80

The chromosome translocation forming the hybrid bcr-abl gene is thought to be the initiating event in chronic myeloid leukaemia (CML) and some cases of acute lymphoblastic leukaemia. To assess the impact of bcr-abl upon haemopoiesis, lethally irradiated mice were reconstituted with bone marrow cells enriched for cycling stem cells and infected with a bcr-abl bearing retrovirus. The mice developed several fatal diseases with abnormal accumulations of macrophage, erythroid, mast and lymphoid cells, and marked strain differences in disease distribution and kinetics. Some mice exhibited more than one neoplastic cell type and, in some instances, these were clonally related, indicating that a progenitor or stem cell had been transformed. While classical CML was not observed, the macrophage tumours were accompanied by a mild CML-like syndrome, probably due to myeloid growth factor production by tumour cells. The erythroid and mast cell diseases were rarely transplantable, in contrast to the macrophage tumours and lymphomas, but all disease types displayed limited clonality. These results establish that bcr-abl confers a proliferative advantage on diverse haemopoietic cells but complete transformation probably involves additional genetic changes.
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PMID:bcr-abl, the hallmark of chronic myeloid leukaemia in man, induces multiple haemopoietic neoplasms in mice. 169 Oct 92

We have compared the proliferative and cytotoxic capacities of a highly purified population of recombinant interleukin-2 (rIL-2)-activated peripheral blood mononuclear cells (PBMNC), termed adherent lymphokine-activated killer cells (A-LAK), in 15 chronic phase (CP) and 10 advanced disease (AD) Ph-positive chronic myelogenous leukemia (CML) patients. The selective enrichment of CML A-LAK cells depended on their propensity to adhere to plastic and to proliferate when cultured in the presence of rIL-2 for 14 days. In both CP and AD patients, 14-day culture resulted in growth of a uniform population of large granular lymphocytes. While less than 10% of the A-LAK cells were CD56-/CD3+ (mature T lymphocytes), 82% +/- 12% of A-LAK cells from early CP patients (diagnosed less than 1 year from study), 84% +/- 3% of A-LAK cells from late CP patients (studied greater than 1 year after diagnosis), and 87% +/- 3% of A-LAK cells from AD patients were CD56+/CD3- (activated natural killer [NK] cells). No bcr gene rearrangement could be found in A-LAK cells from 13 CP and six AD CML patients studied. A-LAK cells from seven early CP CML patients displayed similar cytotoxicity against K562 (80% +/- 7% lysis at effector:target ratio of 20:1) and against Raji (80% +/- 12% lysis) compared with A-LAK from 17 normal individuals (72% +/- 3% K562 lysis, P = .21; 74% +/- 5% Raji lysis, P = .39). However, the cytotoxicity of A-LAK cells from eight late CP patients (59% +/- 5% K562 lysis, P = .02; 52% +/- 8% Raji lysis, P = .02) and that of 10 AD patients studied at any point after diagnosis (31% +/- 3% K562 lysis, P less than .001; 25% +/- 6% Raji lysis, P less than .001) was significantly lower than that of seven early CP CML patients and 17 normals. The proliferative potential of A-LAK cells from seven early CP CML patients (291 +/- 191-fold) was significantly greater than that of A-LAK cells from 17 normal individuals (23 +/- 3-fold, P = .03), eight late CP patients (46 +/- 17-fold, P = .02), and 10 AD patients (5.4 +/- 1.9-fold, P = .01). In contrast to CML A-LAK, K562 cytotoxicity of unstimulated mature peripheral blood NK cells was significantly lower in early CP CML patients than in normals and remained low at all stages of disease.(ABSTRACT TRUNCATED AT 400 WORDS)
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PMID:Diminished A-LAK cytotoxicity and proliferation accompany disease progression in chronic myelogenous leukemia. 169 14

Karyotype and bcr/abl recombinant DNA analyses are two means of detecting the chromosomal aberration in chronic myeloid leukemia. The authors compared these two methods in a retrospective study of 36 patients with CML in which they found the bcr/abl DNA recombinant event in 100% (29 of 29) of those patients who had the Philadelphia chromosome. To achieve this sensitivity, a battery of two bcr probes and three restriction enzymes is necessary. The authors propose a sequential algorithm for efficient use of these probes and enzymes. In 76% of the patients, bcr/abl rearrangement can be detected with a Bgl II digest and a 3' commercial probe. An additional 21% of patients can be detected by a second assay in which the same membrane is rehybridized to a 3' and 5' combination bcr probe. One patient (3%) required an additional restriction enzyme digest with BamH I to detect the recombinant event by the same 3' probe. Karyotype analysis is used to determine cytogenetic remission in patients with CML under therapy. The authors studied the use of DNA analysis by the Southern blot technique to detect a decrease in the relative number of leukemic cells. By dilution studies and densitometric scanning of autoradiographs, the authors were able to detect a 15% decrease in the relative number of cells having the bcr/abl recombinant event. The authors report the preliminary results of three patients in whom they compared the karyotype and recombinant DNA analysis at multiple time points in their clinical course. In conclusion, the bcr/abl recombinant DNA analysis is superior to karyotype for the diagnosis of CML and can be used for monitoring treated patients.
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PMID:Bcr/abl recombinant DNA analysis versus karyotype in the diagnosis and therapeutic monitoring of chronic myeloid leukemia. 169 6

Chronic myelogenous leukemia and one type of acute lymphoblastic leukemia are characterized by a 9;22 chronosome translocation in which 5' sequences of the bcr gene become fused to the c-abl proto-oncogene. The resulting chimeric genes encode bcr/abl fusion proteins which have deregulated tyrosine kinase activity and appear to play an important role in induction of these leukemias. A series of bcr/abl genes were constructed in which nested deletions of the bcr gene were fused to the c-abl gene. The fusion proteins encoded by these genes were assayed for autophosphorylation in vivo and for differences in subcellular localization. Our results demonstrate that bcr sequences activate two functions of c-abl; the tyrosine kinase activity and a previously undescribed microfilament-binding function. Two regions of bcr which activate these functions to different degrees have been mapped: amino acids 1 to 63 were strongly activating and amino acids 64 to 509 were weakly activating. The tyrosine kinase and microfilament-binding functions were not interdependent, as a kinase defective bcr/abl mutant still associated with actin filaments and a bcr/abl mutant lacking actin association still had deregulated kinase activity. Modification of actin filament functions by the bcr/abl tyrosine kinase may be an important event in leukemogenesis.
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PMID:Activation of tyrosinase kinase and microfilament-binding functions of c-abl by bcr sequences in bcr/abl fusion proteins. 170 8


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