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)

Clinical trials with laboratory correlates were conducted in patients with acute leukemia to determine if relationships exist between drug dose and growth of surviving leukemia cells. The therapeutic design was based on findings in the leukemic rat that relate the initial dose of drug and tumor kill to the magnitude of residual tumor proliferation and sensitivity to a second drug. Patients with acute myelocytic leukemia received cytarabine, either 2 or 6 g/m2/72 h by continuous infusion. The presence and magnitude of change between initial and residual tumor after treatment, as measured by change in labeling indices, depended on the "priming" dose of drug. The amount of perturbation correlated with clinical response to cytarabine given at the time of induced proliferation. With results which parallel the rat data, the direct relationship of initial drug dose and proliferation of residual tumor is demonstrated in humans, and lends support to the design of our clinical trials of timed sequential therapy.
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PMID:Growth response of residual leukemia after initial drug therapy. 373 Oct 87

A mathematical model of disease-free survival in acute myelogenous leukemia is formulated in terms of proliferation of the leukemic stem cell compartment. A survivorship function is described which allows for the possibility that some patients may be cured of their disease and which captures the main features of experimental remission-duration curves. The model is used to investigate the effect of the amount of residual disease and the growth rate of the stem cell population on the length of remissions and the chances for cure. A method of comparing clinical trials, with potential for explanatory inference, is exemplified.
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PMID:Mathematical model of remission duration in acute myelogenous leukemia. 386 Feb 93

Studies were conducted in the leukemic mouse and rat to test the hypothesis that enhanced effects of drugs given in sequence relate to a predictable increase in tumor growth and sensitivity to cycle-active agents. The rationale is based on a) evidence that, following drug-induced aplasia, resultant bone marrow proliferation in vivo corresponds temporally with induced humoral stimulatory activity, and on b) models that demonstrate increased cytotoxicity of beta-cytosine arabinoside (Ara-C) to myeloblasts cultured in humoral stimulatory activity (HSA). CD2F1 mice bearing L-1210 leukemia received a course of 60 mg Ara-C/kg every 8th hour (q.8 h) three times on day 0 and on another day in sequence (0,1 through 0,7). The longest survival (250% of controls) was in animals whose second course began on day 3, the time of peak HSA as measured by DNA synthesis induced in L-1210 cells in culture. LBN rats bearing acute myelocytic leukemia (AML) were treated with 100 mg Ara-C/kg q.8 h six times beginning on day 0 and on other days in sequence (0,1 through 0,12). The longest survival was in those treated on day 0,6 (760% of controls), the time of peak serum stimulation, and tumor labeling index (LI). Thirty-seven patients with AML received a single course of therapy with 45 mg Ara-C/kg by a 72-hour infusion and 1.0 mg daunorubicin/kg every day three times. On day 8, the time of peak HSA and tumor LI, Ara-C was again infused. Complete remission was achieved in 56% (65% of all patients less than 60 yr old) with a single cycle of therapy. Median duration of chemotherapy-free remission was 10 months. Of 11 relapsing patients, 8 achieved a second remission with the same regimen. These studies demonstrated that the amount of proliferation of residual tumor and thereby sensitivity to cycle-active drugs given in sequence relates to the initial drug effect on tumor proliferation and the induction of humoral stimulation.
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PMID:Chemotherapy of leukemia in mice, rats, and humans relating time of humoral stimulation, tumor growth, and clinical response. 694 25

Indirect Immunofluorescence (IF) for terminal deoxynucleotidyl transferase (TdT) was used in conjunction with the biochemical assay of TdT enzymatic activity to study human leukaemias before and during therapy. In addition, non-leukaemic marrows were analysed to compare the enzyme expression on normal cells. An excellent correlation was observed between the IF and biochemical methods when specimens contained greater than 5% TdT+ cells (by IF); below this level the biochemical assay was less reliable, while the sensitive IF test could detect isolated TdT+ cells among greater than 10 000 TdT negative cells. The IF method also had the advantage of allowing further immunological characterization of TdT+ cells, by simultaneous labelling of membrane antigens with appropriate antisera. TdT+ cells expressing Ia-like antigens (but lacking other antigens associated with B- and T- lymphoid differentiation) were frequently found in low numbers in remission marrows from acute lymphoblastic leukaemia (ALL) patients. However, similar cells were also observed in remission acute myeloid leukaemia, as well as in non-leukaemic regenerating marrows, and marrow from normal donors. The presence of these normal TdT+ precursor cells therefore precluded the use of either IF or biochemical TdT tests for estimating the degree of residual disease or predicting early relapse in patients with non-T, non-B ALL. In contrast, the detection of TdT+ cells with T lymphoid antigens (HuTLA+) but lacking Ia antigens, in thymic (T-cell)-ALL, but not in normal marrow, allowed the use of this combination of markers to detect minimal residual disease in T-ALL.
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PMID:Immunofluorescent and biochemical studies of terminal deoxynucleotidyl transferase in treated acute leukaemia. 700 2

The nonrandom chromosomal translocation t(8;21)(q22;q22) can be found frequently in acute myelogenous leukemia with maturation (AML-M2). The breakpoint of this translocation has been cloned and characterized, and fusion transcript AML1/ETO has been identified. Reverse transcription polymerase chain reaction (RT-PCR) can be used to amplify the breakpoint site of AML1/ETO in t(8;21)-positive AML-M2 patients. The chimeric transcript can be detected in all 16 (100%) t(8;21)-positive AML-M2 patients. In all samples, the size of the amplified DNA fragments and pattern of restriction digest were identical, indicating that the t(8;21) translocation breakpoint occurs within a single intron of the AML1 and ETO genes. Interestingly, this fusion transcript was also detected in one of 13 AML-M2 patients without the t(8;21) translocation, indicating that a masked translocation involving chromosomes 8 and 21, exists in AML. Minimal residual disease was detected by semi-nested RT-PCR in all four patients tested, who had been in complete remission for 12, 15, 34, and 52 months, respectively. These results indicate that RT-PCR amplification of the AML1/ETO fusion transcript is a powerful tool for diagnosing and monitoring minimal residual disease in AML-M2 patients.
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PMID:Detection of AML1/ETO fusion transcript as a tool for diagnosing t(8;21) positive acute myelogenous leukemia. 750 93

Thy-1 (CDw90) is a phosphatidylinositol-anchored cell surface molecule which, when coexpressed with CD34 in normal human bone marrow, identifies a population of immature cells that includes putative hematopoietic stem cells. To date, the characterization of Thy-1 expression has been confined largely to normal tissues and cell lines. In this study, we evaluated the frequency and intensity of Thy-1 expression as defined by reactivity with the anti-Thy-1 antibody 5E10 in 38 cases of CD34+ acute leukemia (21 acute myelogenous leukemia [AML], 8 chronic myelogenous leukemia [CML] in blast crisis, and 9 acute lymphoblastic leukemia [ALL]). In 34 of 38 cases (89%) the CD34+ cells lacked expression of the Thy-1 antigen. High-density Thy-1 expression was found in 1 case of CML in lymphoid blast crisis, and low-density Thy-1 expression was identified on a portion of the leukemic cells in 2 cases of AML with myelodysplastic features, and 1 case of CML in myeloid blast crisis, suggesting a possible correlation between Thy-1 expression and certain instances of stem cell disorders such as CML and AML with dysplastic features. In contrast, the dissociation of Thy-1 and CD34 expression in the majority of acute leukemias studied suggests that the development of these leukemias occurs at a later stage than the hematopoietic stem cell. Characterization of Thy-1 expression in acute leukemia may eventually provide insights into the origin of the disease. In addition, separation of leukemic blasts from normal stem cells based on Thy-1 expression may prove useful in assessing residual disease, as well as in excluding leukemic blasts from stem cell preparations destined for autologous bone marrow or peripheral stem cell transplantation.
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PMID:Characterization of Thy-1 (CDw90) expression in CD34+ acute leukemia. 754 Aug 89

The acute promyelocytic leukemia (APL)-specific t(15;17) chromosome abnormality is characterized at the molecular level by rearrangement of the PML and RAR alpha genes, resulting in fusion PML/RAR alpha mRNA and a chimeric protein. Besides its relevance in the pathogenesis of the disease, this hybrid gene represents a specific tumor marker that is rapidly detectable by reverse transcriptase-polymerase chain reaction (RT-PCR) in the RNA extracted from leukemic blasts. Several studies have highlighted the clinical relevance of PML/RAR alpha detection, which provides a specific diagnosis, prognostic information, and prediction of relapse when monitoring residual disease during the follow-up. In fact, this hybrid gene is detected in 100% of APLs. Rare cases of patients with a morphological diagnosis of FAB M3 AML who lack the specific PML/RAR alpha abnormality have been reported as being unresponsive to differentiation treatment. Finally, all the studies reported so far on PCR monitoring in APL have documented that the identification of small amounts of residual disease at remission strongly predicts impending relapse. Thus, RT-PCR of the hybrid PML/RAR alpha gene is currently performed prospectively as part of cooperative clinical trials aimed at better addressing post-remission treatment in APL.
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PMID:The PML/RAR alpha fusion gene in the diagnosis and monitoring of acute promyelocytic leukemia. 762 53

Autologous blood stem cell transplantation (ABSCT) has been increasingly used in the treatment of malignant diseases. With the use of hematopoietic cytokines, collection of peripheral blood stem cell (PBSC) has become easier. Contamination of PBSC with tumor cells is supposed to be reflecting the amount of residual tumor cells in the host. G-CSF combined conditioning regimen seems to be effective for ANLL in complete remission (CR) probably by in vivo purging of residual leukemic cells. From our preliminary results, ABSCT can be used as the treatment of choice for standard risk ANLL, and aggressive non-Hodgkin's lymphoma. To clarify the curative potential of ABSCT, prospective clinical trial consisting of remission induction, consolidation of CR, PBSC harvests, and marrow-ablative therapy for ABSCT will be required.
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PMID:[Autologous blood stem cell transplantation-current status and issues. Fukuoka Bone Marrow Transplantation Group]. 764 46

The very rapid development of techniques based on use of the polymerase chain reaction (PCR) for characterizing molecular lesions in leukaemia and lymphoma mow offers the opportunity for monitoring residual disease at a sensitivity of one malignant cell in 10(5) or 10(6) normal cells. Maximal specificity is achieved when the DNA sequences amplified are truly leukaemia-specific (i.e. BCR/ABL in CML, PML/RAR-alfa in APL, AML1/ETO in t(8; 21) AML and CBFB/MYH1 in inv(16) AML). A good level of sensitivity may also be achieved by using immunoglobin heavy chain (IGH) and T-cell receptor (TCR) gene rearrangements if a clonospecific probe can be generated. For clinical purposes the crucial issues are the following: can PCR techniques be used for confirmation of diagnosis and evaluation of extent of disease? Can PCR data obtained be developed to quantitate the PCR product and thereby increase its predictive value? These and other issues are still a matter of debate and several studies are presently in progress to address these points.
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PMID:Minimal residual disease detection in human leukemias: biologic and clinical significance. 765 31

In the majority of patients with acute myeloid leukemia (AML) immature leukemic subpopulations expressing myeloid markers and terminal deoxynucleotidyl transferase (TdT) are present. The normal counterparts of these double-positive cells are rare in bone marrow (BM) (< 0.03%; if they occur at all) and are not detectable in peripheral blood (PB). In 14 patients with TdT+ AML at diagnosis, we have performed a prospective follow-up study to monitor the myeloid-marker+, TdT+ cells during and after chemotherapy. One patient did not obtain complete remission (CR), a second patient relapsed under therapy, whereas the other 12 patients were in cytomorphological CR at the end of chemotherapy. During subsequent follow-up, seven of these 12 patients developed one or two relapses (total of ten relapses). Nine of these ten relapses were preceded by a gradual increase of myeloid-marker+, TdT+ cells in BM and PB samples over a period of 14-38 weeks. Based on comparable results in BM and PB samples and doubling times of 15-20 days, we propose that monitoring of AML patients should include PB sampling each 4-6 weeks. In one patient the relapse was not preceded by a gradual increase of double-positive cells. This false negative result was caused by a phenotypic shift, since at relapse the AML cells did not express TdT. In the five AML patients who still are in continuous cytomorphological CR for 32-46 months we repeatedly detected relatively high percentages of myeloid-marker+, TdT+ cells in BM (up to 0.1%) and PB (up to 0.02%). Although we could not prove the leukemic origin of these double-positive cells, they might represent residual dysplastic AML cells which survived chemotherapy but which are not capable of causing leukemia regrowth as yet. This would be in line with recent polymerase chain reaction studies, which could demonstrate the persistence of leukemic clones in the majority of AML patients in continuous CR. It is concluded that double immunofluorescence labeling for myeloid markers and TdT is useful for detection of residual disease in TdT+ AML patients. A gradual increase of double-positive cells is suggestive for leukemic cell growth and can be used to predict relapse.
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PMID:Detection of residual disease in AML patients by use of double immunological marker analysis for terminal deoxynucleotidyl transferase and myeloid markers. 768 Apr 3


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