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)

Acute myelogenous leukemia (AML) of the inbred Wistar/Furth (W/Fu) rat is pathophysiologically similar to human AML. Subcutaneous transplantation of 1.0 X 10(6) cells of a clonal tissue culture line of W/Fu AML into 6- to 8-week-old rats produced local myeloblastomas in 8--10 days which progressed to infiltration of regional nodes, replacement of greater than 90% of the bone marrow, ascites, and fatal peripheral blood leukemia with concomitant hyperlysozymemia. Single doses of adriamycin, daunomycin, actinomycin, cytosine arabinoside, or Cytoxan in rats with 1.0 cm myeloblastomas produced complete tumor regression while bu-sulfan, vinblastine, vincristine, dexamethasone, and Methotrexate was relatively ineffective. Responses were associated with delay in progression to peripheral blood leukemia and prolonged survival. Similar results were obtained following treatment of rats with already disseminated leukemia. The demonstration of response to drugs known active against human AML indicates that the W/Fu AML should be a valuable model for rapid evaluation of new chemotherapeutic agents for clinical use.
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PMID:Chemotherapeutic remissions in Wistar Furth rat acute myelogenous leukemia: a model for human AML. 6 30

Gonadal and other types of leukemic "sanctuaries" are probably the main causes of hematological relapse in the treatment of acute leukemia. The introduction of high-dose Methotrexate (HDM) in a consolidation phase is based on theoretical considerations and the use of HDM in malignant tumors. Three courses of Methotrexate, 500 mg/sq.m. at 3-weekly intervals, has been used as part of a consolidation therapy in Norway during the last two years to 59 children with ALL and one with AML. One child died following HDM. Postmortem examination showed that she was not in complete remission at the time. Among 154 courses of HDM in the 60 patients were eight severe reactions, including six cases of allergic-toxic skin reactions. Two patients developed a Stevens-Johnson's like syndrome. Stomatitis was common in those with toxic reactions. The risk of HDM in patients who are not in complete remission is stressed and the use of rescue therapy with two doses of Leukovorin instead of one is recommended. Forty of forty-two children in 1st complete remission have been in sustained primary remission for 4 to 28 months. Two of these 40 children died after about a year from infections. Only two patients so far have relapsed.
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PMID:High dose methotrexate in acute lymphocytic leukemia in childhood. 14 30

Thymidylate synthetase (EC 2.1.1.B.) from blast cells of patients with acute myelocytic leukemia has been purified more than 1470-fold by affinity column chromatography. Methotrexate was the affinity ligand. dUMP was found to be a necessary additive for retention of the enzyme by the affinity column. Disc electrophoresis and sucrose density gradient centrifugation revealed a single enzyme species with a molecular weight of 76,000. The enzyme exhibits a temperature-dependent conformational change with activation energies of 5.3 +/- 0.4 and 17.3 +/- 1.9 kcal/mol, respectively, above and below a transitional temperature of 35 degrees. This conformational change is reflected in the binding affinity of dUMP but not of 5,10-methylenetetrahydrofolate. The enzyme displays a broad pH maximum in the range of pH 7.4 to 8.8. The Michaelis constants for dUMP and (+/--L-5,10-methylenetetrahydrofolate are 1.8 +/- 0.2 and 31 +/- 8.3 micrometer, respectively. Initial velocity and product inhibition studies reveal the enzymic mechanism to be ordered sequential. dUMP binds before 5,10-methylenetetrahydrofolate and dihydrofolate is released before TMP. 5-Fluoro-2'-deoxy-5'-uridylate (FdUMP) behaves as in irreversible inhibitor with a Ki of 1.68 +/- 0.45 nM. The enzyme has a turnover number of 6 min-1 per FdUMP binding site. Methotrexate inhibits noncompetitively with respect to dUMP and binds tighter to the enzyme in the presence of dUMP. Methotrexate antagonizes inactivation of the enzyme by FdUMP.
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PMID:Human thymidylate synthetase derived from blast cells of patients with acture myelocytic leukemia. Purification and chracterization. 26 53

To test the relationship between DMs and drug resistance in newly established AML cell lines, KY821, and its clone KY821A3, the latter had lost DMs during cloning, were cultured in increasing concentrations of MTX. KY821 became resistant against 2 x 10(-4) M MTX, whereas KY821A3 did against 2 x 10(-5) M MTX in a same period. Enhanced enzyme activities of DHFR were correspondent to the increased DMs numbers and DHFR gene amplification in both resistant clones. The amplified DHFR gene was located on DMs by in situ hybridization. These data indicated that the presence of DMs in KY821 would facilitate the acquisition of drug resistance.
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PMID:A new myeloblastic leukemia cell line with double minute chromosomes. Induction of methotrexate resistance and dihydrofolate reductase gene amplification. 156 Jun 71

The hyperthermia as well as radiation responses of multidrug resistant (CEM/VLB100 with classical MDR and CEM/VM-1 with atypical MDR), methotrexate resistant (CEM/MTX) subclones of CCRF-CEM T-lineage ALL cell line were compared with those of a drug sensitive (CEM-1-3) subclone from the same parent cell line. Also analyzed were the hyperthermia as well as radiation responses of multidrug resistant (HL60/AR) and drug sensitive subclones of the HL60 AML cell line. Notably, the drug resistant subclones of CEM and HL60 were as sensitive to hyperthermia as were the drug sensitive subclones. Importantly, no thermotolerant plateau was observed in the hyperthermia survival curves of the drug resistant subclones, indicating that drug/multidrug resistance is not associated with a greater likelihood of thermal tolerance development during hyperthermia. Similarly, the drug resistant CEM and HL60 subclones were not more radiation resistant than the drug sensitive subclones. Thus, the classical or atypical forms of multidrug resistance or methotrexate resistance of the analyzed leukemic cell lines were not associated with radiation resistance. Furthermore, the radiation survival curves of the drug resistant subclones lacked a distinct initial shoulder and their n values were not greater than those of the drug sensitive subclones, suggesting that multidrug resistance is not associated with an increased ability to repair or accumulate sublethal radiation damage. Our findings provide evidence that there is no apparent association between drug/multidrug resistance and heat or radiation sensitivity of CEM T-lineage ALL or HL60 AML leukemia cells. The results of this study indicate that acquired resistance to methotrexate, vinblastine, vincristine, etoposide, actinomycin-D, adriamycin, or daunomycin, or pleiotropic multidrug resistance do not necessarily confer radiation resistance for human leukemic cells.
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PMID:Radiation and heat sensitivity of human T-lineage acute lymphoblastic leukemia (ALL) and acute myeloblastic leukemia (AML) clones displaying multiple drug resistance (MDR). 157 9

The effects of methotrexate (inhibiting dihydrofolate reductase) and nitrous oxide (inactivating methionine synthase) on intracellular folate coenzyme levels of leukemic cells were studied. Blast cells from 10 cases of acute myeloid leukemia (AML) and 5 cases of acute lymphoid leukemia (ALL) were incubated with 5 x 10(-8) M [3H] 5-formyltetrahydrofolate (5-formylTHF) for 18 h to label intracellular folate pools, which were subsequently quantitated by high performance liquid chromatography (HPLC). In AML, 5-methylTHF made up 53% of the total folate pool followed by 10-formylTHF (26%), 5-formylTHF (10%), THF (9%) and DHF (1%). Cells from ALL differed from AML (p less than 0.05) with respect to 10-formylTHF (17%) and DHF (10%). Exposure to nitrous oxide (8 h) caused an equal decrease of 10-formylTHF and 5-formylTHF in both AML (30%) and ALL (45%), whereas 5-methylTHF increased (130%). Methotrexate (4 h, 10(-6) M) caused an accumulation of DHF and a decrease of 5-methylTHF in both AML (32%) and ALL (12%). A specific reduction of the 10-formylTHF (50%) and 5-formylTHF (25%) pools was noticed in ALL. Exposure to nitrous oxide prior to methotrexate treatment aggravated the reduction of 10-formylTHF and 5-formylTHF presumably by impaired replenishment from the 5-methylTHF pool. In conclusion, this study demonstrates a significant difference in folate coenzyme distribution between cells from AML and ALL. Moreover it is shown that nitrous oxide and methotrexate treatment of leukemic cells cause an accumulation of 5-methylTHF and DHF respectively at the expense of other folate forms. The presence of substantial amounts of DHF in cells from ALL together with the specific reduction of 10-formylTHF (necessary for purine synthesis) during MTX treatment may in part explain the efficacy of methotrexate in the treatment of ALL.
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PMID:Effect of nitrous oxide and methotrexate on folate coenzyme pools of blast cells from leukemia patients. 201 7

From May 1985 to July 1989, 76 patients with leukemia (30 acute myelogenous leukemia, 24 acute lymphoblastic leukemia and 22 chronic myeloid leukemia) were randomized to receive either cyclosporin (CSP) alone (n = 39) or CSP combined with methotrexate (CSP + MTX, n = 37) for graft-versus-host disease (GVHD) prophylaxis. Patients were conditioned with total body radiation and cyclophosphamide followed by bone marrow infusion from an HLA-identical sibling. Engraftment of the transplanted bone marrow was similar in both groups. The incidence of moderate to severe acute GVHD was significantly higher in the CSP group compared with the CSP + MTX group (20 (51%) versus 9 (25%), chi 2 = 4.76, p less than 0.02). There was no significant difference in the incidence of chronic GVHD. Survival was significantly better for the CSP + MTX group (63 +/- 16%) compared to CSP alone (42 +/- 18%). Leukemia-free survival tended to be better for the CSP + MTX group (55 +/- 17% versus 32 +/- 16%).
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PMID:Combination of cyclosporin and methotrexate for prophylaxis of acute graft-versus-host disease after allogeneic bone marrow transplantation for leukemia. 220 50

Between January 1980 and March 1983, a study was conducted on the effects of intensification therapy in 20 adult acute leukemia patients who had achieved complete remission with induction therapy. Intensification therapy consisted of cyclic administration of six combination therapies given at gradually longer intervals, using daunorubicin, cytosine arabinoside, 6-mercaptopurine and prednisolone (DCMP), cyclocytidine (DCyMP), vincristine (DCVP), behenoyl-ara-c (BHAC-DMP), aclacinomycin (BHAC-AMP) and (ACM-MP). Six combinations were given sequentially at one-month intervals, at 2-, 3-, 4-, 5- and eventually 6-month intervals, until 5-year survival. The median remission duration was 38 months for AML, and 17 months for ALL. The median survival was 66 months for AML, and 37 months for ALL. The five year survival rate was 50%. Nine of the 20 patients are still alive. Methotrexate and prednisolone were administered intrathecally for prophylaxis of CNS leukemia on Day 4 for each intensification therapy. There was no CNS leukemia. This intensification protocol was shown to be effective in improving the prognosis of adults acute leukemia.
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PMID:[An intensification therapy of adults acute leukemia]. 264 96

We report a single center experience of 222 patients (pts) less than 18 years old transplanted from 1973 to 1987. The median age was 11 years (1-18). The donor was a monozygotic twin (9 pts), an HLA-id sibling (193 pts), an HLA-id, parent (9 pts), a mismatched related donor (9 pts) and a matched unrelated donor (1 pt). Ninety-six pts were transplanted for SAA. Conditioning varied with time but the majority (59 pts) received CY 150 mg/kg and 6 Gy TAI. The long term actuarial survival is 66% with a median follow-up of 3 years. The group who received CY 200 mg/kg and MTX had a 33% long term survival (LTS). GVH was the main complication with 40% acute and 37% chronic GVHD. Chronic GVHD tended to improve with time after 2 to 4 years of evolution. Ninety pts were transplanted for leukemia (35 AML, 45 ALL and 11 CGL), 20 pts were in relapse. Pts in CR had a LTS of 40%, in pts in relapse, it was 12%. The main causes of death were: interstitial pneumonitis (30%), relapse (27%), GVH (15%). Thirty-five pts were transplanted for constitutional disease: Fanconi anemia (FA) (26 pts), Dyskeratosis congenita (2 pts), Blackfan-Diamond erythroblastopenia (2 pts), Glanzmann thrombasthenia (1 pt), osteopetrosis (1 pt) and Gaucher's disease (1 pt). In FA, the LTS is 70% with a CY 20 mg/kg, 5 Gy TAI regimen. In all disease categories, we did not find any influence of donor's sex on GVH and survival.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Pediatric bone marrow transplantation for leukemia and aplastic anemia. Report of 222 cases transplanted in a single center. 267 24

Between January 1980 and March 1983, a study was conducted into the effects of postremission therapy on 20 patients with acute leukemia who had achieved complete remission through induction therapy. Postremission therapy consisted of cyclic administration of six combination therapies given at gradually longer intervals. Postremission therapy used DCMP (D, daunorubicin; C, cytosine arabinoside; M, 6-mercaptopurine; P, prednisolone), DCyMP (Cy, cyclocytidine), DCVP (V, vincristine), BHAC-DMP (BHAC, behenoyl-ara-c), BHAC-AMP (A, aclarubicin) and ACM-MP (ACM, aclacinomycin). Six combinations were given sequentially starting at one month interval, and then at 2, 3, 4, 5 and eventually 6 month intervals until 5 year survival was reached. The median remission duration was 38 months for acute myelogenous leukemia (AML), and 17 months for acute lymphoblastic leukemia (ALL). The median survival was 66 months for AML, and 33 months for ALL. The survival rate at 5 years was 60% for AML., 40% for ALL, and 50% in all 20 patients. Methotrexate and prednisolone were administered intrathecally for prophylaxis of CNS leukemia on Day 4 of each stage of postremission therapy. There was no CNS leukemia. This postremission therapy was shown to be effective in improving the prognosis of adults with acute leukemia.
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PMID:An eight year experience with gradually longer interval postremission therapy for adults with acute leukemia. 278 38


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