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)

Forty-five children with acute nonlymphoblastic leukemia in relapse received a total of 56 courses of L-asparaginase combined with vincristine and prednisone. The complete remission rate of 40% (12 of 30 trials) in patients resistant to vincristine and prednisone was almost identical to that in children still sensitive to vincristine and prednisone (42%, 11 of 26 trials). The complete remission rate of 38% (14 of 37 exposures) in those children who had not received L-asparaginase previously compared favorably with the complete remission rate in those children who had received prior L-asparaginase (47%, 9 of 19 exposures). Forty-seven of the 56 induction trials were in children with 1 or more remissions and 14 of these were in children with 3 or more prior remissions. Toxicity was minimal.
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PMID:Remission induction with L-asparaginase, vincristine, and prednisone in children with acute nonlymphoblastic leukemia. 106 23

In acute lymphoblastic leukaemia the combination prednisone-vincristine induces more than 85% complete remissions. L-asparaginase which was used in complete remissions, seemed to increase their duration. Actually the best maintenance treatment consists in the combination of 6-mercaptopurine and methotrexate interrupted by reinductions. In other respects C.N.S. prophylaxis with intrathecal methotrexate and craniospinal irradiation is necessary. The well-known prognostic factors are: age, leucocytosis, tumoral syndrome, and cytological type: 216 cases of long remission have been observed. One group of these patients was treated by old methods: this represents 0.8 to 1% of the material, while 20% were treated by recent protocols with reinductions (20%).
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PMID:Treatment of acute lymphoblastic leukaemia. 107 Apr 68

Spleen antibody-forming cells of mice yield a 3- to 10-fold increase in their response to sheep erythrocyte antigen if they are acutely infected by lactate dehydrogenase-elevating virus. This early stimulation is replaced by a long-term inhibition of the antibody-forming cells as the viremia goes into its persisting chronic stage. These contrasting immunological phenomena are examined as contributing factors responsible for the enhancement by this virus of asparaginase (EC 3.5.1.1; L-asparagine amidolydrolase) therapy against leukemia in mice, and for the alteration of the susceptibility of mice to various neoplastic processes.
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PMID:Antibody-producing cells: virus-induced alteration of response to antigen. 108 81

Immobilized asparaginase was prepared by embedding asparaginase (which is effective for remission in children with leukemia) into fibrin polymer formed by fibrinogen-fibrin conversion in the presence of thrombin. The immobilized asparaginase film did not dissolve in 6 mol/1 urea, suggesting that blood coagulation factor XIII participates in the cross-linking between fibrins and between fibrin and asparaginase.
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PMID:Immobilized L-asparginase embedded in fibrin polymer. 109 44

Essentially all the drugs which are active against human leukemias and lymphomas are active against one type or another of the rodent leukemias and lymphomas. Leukemia L1210 has been generally the most successful screening tool for clinically active compounds. Leukemia P388, however, seems to be better in detecting active antibiotics and natural products and P1534 is particularly sensitive to the Vinca alkaloids, while L5178Y, EARAD, and 6C3HED are useful in detecting the activities of various asparaginase containing fractions. Cell cultures of these leukemias can demonstrate mechanism of drug action and quantitate resistance. Spontaneous AKR leukemia is a model of the advanced human disease. In these leukemias vincristine and prednisone produce a 4 log cell kill. Cytoxan and arabinosyl cytosine (Ara-C) are also effective. On the other hand drugs such as mercaptopurine (6MP) and methotrexate which are highly active in the maintenance phase of acute lymphocytic leukemia (ALL) and in L1210 have little or no activity against the AKR spontaneous system. Mouse leukemias can also detect schedule dependence, synergistic combinations, cross resistance, oral activity, and the ability of drugs to pass the blood brain barrier. A case in point is the Ara-C analog 2,2'-anhydro-arabinofuranosyl-5-fluorocytosine (AAFC) which is not schedule dependent, is active orally, is potentiated by thioguanine, and is effective against intracerebrally inoculated mouse leukemia. AAFC and its analogs might thus be a considerable improvement over Ara-C which is at the present time the most important component of the combination treatment of acute myelogenous leukemia (AML).
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PMID:Murine and human leukemias. 110 47

This study presents results of single-drug and combination chemotherapy of the transplantable acute leukemia L5222 in BD IX rats. In leukemia L5222 there is a direct relationship between the number of transplanted cells and mean life expectancy. After single-drug therapy with L-asparaginase, 1,3-bis(2-chloroethyl)-1-nitrosourea (BCNU), cyclophosphamide, cytosine arabinoside, daunomycin, 6-mercaptopurine, methylglyoxal bis(guanylhydrazone) dihydrochloride, prednisolone, or vincristine, the best therapeutic effect was observed with BCNU and cyclophosphamide. A massive-dose therapy with BCNU repeated twice or a conbination of vincristine with cyclophosphamide or BCNU with cyclophosphamide yielded a high percentage of cures. Morever, leukemia L5222 seems to be suitable for studying the influence of drugs on the proliferation kinetics of leukemia cells.
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PMID:Chemotherapy of the transplantable acute leukemia L5222 in rats. 112 Mar 7

Of 4 lines of myelogenous rat leukemias induced by N-nitrosobutylurea (NBU), DBLA-6 was selected as a screening model for antileukemic agents because of the following characteristics: a) High transplantability either by intravenous (i.v.) or intraperitoneal (i.p.) inoculation; b) linear relationship between inoculum size and survival time; c) marked increase of leucocyte counts in the peripheral blood as the tumor progresses after intravenous inoculation. To investigate reliability in its predicting clinical efficacy, its sensitivity to known antileukemics was studied. To determine the effects, a change of leucocyte counts in the peripheral blood together with the prolongation of life span was checked in the following systems; i.v.-i.v. (i.v.-inoculation, i.v.-injection), i.v.-i.p., i.p.-i.p., i.p.-i.v. Fifty percent cure was obtained with Vincristine, Vinblastine, Daunorubicin, 6-Mercaptopurine, and alkylating agent 838D or 864T. The success of treatment was measured by decrease of leucocytes. Methotrexate, cytosine arabinoside (Ara-C), and cyclophosphamide showed only poor effects, and Mitomycin C, L-asparaginase, and Bleomycin were ineffective. In addition, the chemotherapeutic effects of Vincristine and 864 on this leukemia were quite dependend both on the route of drug injection and on the site of tumor inoculation. Subsequently, our studies are being extended to cover the correlation between drug distribution and tumor localization or dissemination.
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PMID:Sensitivity of DBLA-6 leukemia of rats to known antitumor agents in relation to their clinical effects. 116 99

Although cellular drug resistance is considered to be an important cause of the poor prognosis of children with relapsed acute lymphoblastic leukaemia (ALL), the knowledge of drug resistance in these patients is very limited. Different aspects of drug resistance were studied in 17 children with relapsed ALL. The in vitro sensitivity profile was determined using the MTT assay. Cells from relapsed children were significantly more resistant to 6-thioguanine, prednisolone, cytosine arabinoside, daunorubicin (DNR), mustine-HCl and mafosfamide but not to L-asparaginase and vincristine (VCR) than cells from 41 children with ALL at initial diagnosis. Some relapsed patients showed a general drug resistance while others were resistant to only 1-3 drugs. The relevance of the multidrug resistance (MDR) model was analysed: In all DNR- and VCR resistant cases a co-resistance to drugs not involved in the MDR model was found. P-glycoprotein was not detected in any of 28 untreated and 14 relapsed samples tested. VCR- and DNR accumulation in the most resistant cells were not lower than in sensitive cells. Resistance modifiers did not potentiate the cytotoxicity of VCR and DNR. We conclude that resistance to anthracyclines and vinca alkaloids in childhood relapsed ALL is not due to P-glycoprotein mediated MDR. Different types of drug resistance varying from a resistance to only one drug to a general chemoresistance, can be detected in children with relapsed ALL. VCR and L-asparaginase seemed to be only infrequently involved in drug resistance. Knowledge of drug resistance might lead to more effective and less toxic therapies for children with relapsed ALL.
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PMID:Different types of non-P-glycoprotein mediated multiple drug resistance in children with relapsed acute lymphoblastic leukaemia. 135 Feb 7

L-asparaginase from Erwinia provides an alternative to the enzyme from E. coli for the effective treatment of acute lymphoblastic leukaemia. A procedure was required for the large-scale partial purification of the recombinant Erwinia enzyme cloned and expressed in Erwinia. Enzyme was extracted from Erwinia at high pH and extraneous protein precipitated at low pH. S-Sepharose FF was selected as the medium of choice for the chromatography step since it was adequate for the high flow rates required (linear flow rate 315 cm h-1) and the methylsulphonate functional groups exploited the high pI of the enzyme by allowing binding of L-asparaginase at pH 4.8 while most of the other proteins passed through the column. The useful capacity of the matrix was up to 34 mg enzyme/ml matrix at a linear flow rate of 95 cm h-1 and 15.4 mg enzyme/ml matrix at a linear flow rate of 315 cm h-1. Weakly bound protein was removed by a wash at pH 6.0. The L-asparaginase was eluted by a wash at pH 6.8 (linear flow rate 95 cm h-1) and was substantially pure, only requiring polishing steps to be suitable for use as a parenteral agent. The purity of the protein was complemented by a 92% recovery of active enzyme from this cation-exchange matrix.
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PMID:Rapid large-scale preparation of recombinant Erwinia chrysanthemi L-asparaginase. 136 93

Forty-six consecutive patients with acute lymphoblastic leukaemia (ALL), having a median age of 23 years (range 14 to 64), underwent induction and consolidation chemotherapy with weekly parenteral vincristine, adriamycin, l-asparaginase and daily oral prednisone (VAAP), followed by standard central nervous system (CNS) prophylaxis. Maintenance therapy was given for 3 years and consisted of daily 6-mercaptopurine, weekly methotrexate, and monthly intrathecal chemotherapy, with drug intensification comprising either vincristine, adriamycin and l-asparaginase (VAA) or cyclophosphamide, vincristine, cytosine arabinoside and prednisone (COAP). Complete remission (CR) was achieved in 36 patients (78%) and only the FAB L1 morphology was a significant predictive factor (Chi-squared = 3.91: p < 0.05). Eight of the 10 non-responders had significant drug resistance and 3 deaths were associated with marrow hypoplasia. Median follow-up is 52 months. Median duration of CR is 28 months, median survival of all patients is 16 months, and for those who achieved CR is 44 months. There was no difference between the two maintenance arms. Significant prognostic factors for survival are French-American-British (FAB) subtype, in which the L1 is better than L2 (p = 0.05), and age (p = 0.035). Nineteen patients have experienced medullary relapse and 7 (37%) achieved subsequent CR; this is durable in a single patient who underwent allogeneic bone marrow transplantation. Eight patients (17%) had CNS disease at diagnosis; 5 achieved CR and 1 is alive and disease-free at 65+ months. There has been 1 CNS relapse. These results demonstrate that prolonged remissions and survival can be achieved with this protocol and many patients possibly cured. The level of toxicity is acceptable and the pattern of induction failure indicates that a margin exists for intensifying chemotherapy and thereby possibly further improving results.
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PMID:Treatment of acute lymphoblastic leukaemia (ALL). 139 40


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