Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:3.5.1.1 (asparaginase)
 2,695 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Forty-one children with refractory acute nonlymphocytic leukemia (ANLL) were treated from March 1975 to February 1979 with a schedule-dependent combination of methotrexate (MTX) and L-asparaginase. Intravenous (IV) MTX was followed 24 hours later by IV L-asparaginase (10,000 units [U]/m2). The MTX dose was started at 60 to 100 mg/m2 and was escalated by 20 to 40 mg/m2 as tolerated. This sequence was repeated every 7 to 10 days. Eight patients (20%) achieved a complete remission (CR) and six others had a partial response (PR), with clearance of blasts from the peripheral blood and reduction of bone marrow blasts to less than 25% of nucleated marrow cells. Responding patients received a median maximum MTX dose of 120 mg/m2 (range, 60 to 220 mg/m2). The median number of courses required to achieve a CR was 6 (range, 2 to 13 courses). Toxicity consisted of allergic reactions to L-asparaginase (n = 12), stomatitis (n = 6), minimal elevation of hepatic enzymes (n = 2), and hyperglycemia (n = 1). Treatment was given on an outpatient basis in 95% of all courses. The data indicate that this combination therapy has antileukemic activity and is relatively nontoxic in childhood ANLL.
Cancer 1990 Jun 15
PMID:Methotrexate plus L-asparaginase. An active combination for children with acute nonlymphocytic leukemia. 234 Apr 62

The effectiveness and toxicities of high-dose cytosine arabinoside with L-asparaginase (HiDAC-ASNase) were evaluated in 41 patients with "poor risk" acute nonlymphocytic leukemia (ANLL). Twenty-four patients had either refractory or relapsed primary ANLL, and 17 had ANLL secondary to prior cytotoxic chemotherapy or an underlying hematologic disorder. The overall complete remission (CR) rate was 37%. The CR rates for primary and secondary ANLL were almost identical. Furthermore, advanced age alone did not adversely influence the CR rate. The median CR duration was 302 days with no differences between primary and secondary ANLL. The induction death rate was 24%. Predictors for induction deaths included poor initial performance status, fever at the time of presentation, low cholesterol and/or albumin, and an initial bone marrow aspirate with greater than 50% blasts. These data indicate that HiDAC-ASNase is a moderately effective regimen for patients with poor prognosis ANLL including secondary ANLL.
Cancer 1990 Jun 15
PMID:High-dose cytosine arabinoside and L-asparaginase therapy for poor-risk adult acute nonlymphocytic leukemia. A retrospective study. 234 Apr 64

The percent of marrow blasts on day 7 of therapy was determined for 128 children with previously untreated acute lymphoblastic leukemia and white blood count (WBC) greater than or equal to 50,000/microliters and/or lymphomatous features enrolled in the Childrens Cancer Study Group trial of the Berlin Frankfurt Munster 76/79 regimen (CCG-193P). Patients received four-drug induction therapy including vincristine, prednisone, l-asparaginase, and daunomycin. Ninety-seven patients had fewer than 25% marrow blasts on day 7. Of these, 94 survived and maintained remission through day 28 and were designated early responders. Thirty-one patients had greater than 25% marrow blasts on day 7. Of these, 28 survived and achieved remission on day 28 and were designated late responders. The outcome of patients who underwent a day 7 marrow aspiration was similar to those who did not. Early responders had a 77.4% +/- 4.5% (standard deviation) 3-year estimated disease free survival, while late responders had 47.3% +/- 9.8% (P less than 0.001). Early responders had a superior outcome both in the subset with an initial WBC less than 50,000/microliters (P = 0.025) and in the subset with a WBC greater than or equal to 50,000/microliters (P = 0.01). The day 7 marrow response had prognostic value in this population of children with unfavorable presenting features who received four-drug remission induction therapy.
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PMID:Day 7 marrow response and outcome for children with acute lymphoblastic leukemia and unfavorable presenting features. 235 86

The modulation of methotrexate polyglutamylation by L-asparaginase has been examined in mice bearing sublines of leukemia L5178Y that have different sensitivities to asparaginase. A single i.p. injection of 200 IU/kg of asparaginase completely inhibited ascites tumor cell growth in the parental L5178Y/S+ tumor for 120 h compared to 72 and 30 h in the L5178Y/S and L5178Y/S+/- sublines, respectively. Similarly, DNA and protein synthesis were completely inhibited by asparaginase for 96 h in L5178Y/S+ cells, but only for 72 and 24 h in L5178Y/S and L5178Y/S+/- cells. In each tumor the temporal patterns of depletion and recovery of S-phase cells were similar to the patterns of suppression and recovery of DNA and protein synthesis observed in that tumor. When methotrexate was administered at either 96 or 24 h after asparaginase during the asparaginase-induced S-phase nadirs of L5178Y/S+ and L5178Y/S+/- cells, respectively, subsequent methotrexate polyglutamylation was inhibited 83 and 92% compared to tumor cells exposed to methotrexate only. Recovery of methotrexate polyglutamylation in both tumors following L-asparaginase pretreatment coincided in time with the return in the fraction of S-phase cells towards the pretreatment values. The inhibition of methotrexate polyglutamate accumulation by asparaginase was associated with decreased retention of methotrexate in tumor cells. In contrast, asparaginase had no significant effect on methotrexate polyglutamate accumulation and methotrexate retention when administered after methotrexate. These data indicated that the asparaginase-induced modulation of methotrexate polyglutamylation in mice was directly related to the time course of inhibition and recovery of tumor cell proliferation by asparaginase, and thus varied with the intrinsic sensitivity of the individual tumor to the enzyme.
Cancer Res 1987 Mar 01
PMID:L-asparaginase-induced modulation of methotrexate polyglutamylation in murine leukemia L5178Y. 243 14

The effects of eight antitumoral drugs known to cause anaphylactoid side effects in clinical use were studied in dogs. Blood pressure, heart rate, and blood and plasma histamine levels were monitored. L-asparaginase, methotrexate, 5-fluorouracil, bleomycin, and cisplatin had no effect on these parameters. Doxorubicin, Vehem (teniposide), and Vepeside (etoposide) induced hypotension, tachycardia, and a rise in histamine levels. In the cases of Vehem and Vepeside, the excipient (respectively, cremophor EL and tween 80) induced the same effects. These agents, like elliptinium, which had been previously studied, induce nonspecific histamine release--unlike the other drugs studied. The mechanism of clinically observed anaphylactoid side effects is discussed in the light of these findings.
Cancer Chemother Pharmacol 1988
PMID:Study of histamine release induced by acute administration of antitumor agents in dogs. 245 32

The stability of solutions of the antitumour antimetabolites, vinca alkaloids, podophyllotoxins, interferons, steroids and platinum drugs as well as maytansine, asparaginase, amsacrine, flavone-8-acetic acid, mitoguazone, and N-phosphonoacetyl-L-aspartate (PALA) is reviewed. Much of the published work has been done with biological, not stability-indicating, assays; thus, the relevant results should be used with caution. With this proviso, almost all of these drugs can be stored in solution for several days at room temperature or 4 degrees C. Most reports also suggest that the drugs that have been tested are stable when frozen in solution. For a number of the drugs, particular precautions are required; for instance, amsacrine should not be mixed with chloride-containing solutions, whereas cisplatin is most stable in solutions containing greater than 0.1 M chloride.
Cancer Chemother Pharmacol 1989
PMID:Stability of solutions of antineoplastic agents during preparation and storage for in vitro assays. III. Antimetabolites, tubulin-binding agents, platinum drugs, amsacrine, L-asparaginase, interferons, steroids and other miscellaneous antitumor agents. 246 80

Escherichia coli asparaginase (Asnase) pretreatment of Asnase-sensitive L5178Y cells in vitro is thought to antagonize methotrexate (MTX) cytotoxicity through nonspecific inhibition of protein synthesis and MTX uptake. We have reexamined the mechanism of this interaction in view of recent data demonstrating the importance of MTX metabolism to polyglutamate derivatives (MTXPGs) in the cytotoxic effects of the antifolate. After a 3-hr exposure to 0.5 microM MTX, 67% of intracellular drug was in the form of MTXPGs containing a total of 2 to 5 glutamyl residues (MTX-Glu2-5), and cloning efficiency in drug-free medium was only 7% of untreated control. After a 3-hr pretreatment with E. coli Asnase (0.1 unit/ml), [3H]thymidine incorporation dropped by 29%, MTXPG formation during subsequent MTX exposure decreased by more than one-half (MTX-Glu2 unchanged; MTX-Glu3 and 4 decreased to 51.7 and 18.5% of levels achieved in cells not pretreated with Asnase; no MTX-Glu5 formed), and cloning efficiency increased to 71% of untreated control. This effect was not due to decreased MTX uptake into L5178Y cells or to decreased intracellular free L-glutamate or L-glutamine levels. A 3-hr exposure of L5178Y cells to media lacking L-isoleucine, an essential amino acid for cell growth, prior to MTX exposure inhibited [3H]thymidine incorporation by 37%, decreased subsequent MTXPG formation by 62%, and increased subsequent cloning in drug-free medium to control levels. Decreased MTXPG formation was responsible for the prevention of MTX cytotoxicity seen after both pretreatments. Unmetabolized MTX rapidly left L5178Y cells after removal of extracellular MTX. Consequently, lower levels of unbound intracellular drug, a prerequisite of drug activity, were maintained in pretreated than in control cells after passage in drug-free medium. Asnase pretreatment protects L5178Y cells from the cytotoxic effects of MTX, possibly through inhibition of cell growth which nonspecifically decreases MTXPG formation.
Cancer Res 1985 Jan
PMID:Prevention of methotrexate cytotoxicity by asparaginase inhibition of methotrexate polyglutamate formation. 257 94

Two hundred and nine children (20 years and below) diagnosed as acute lymphoblastic leukemia between January 1980 and December 1983 were retrospectively analysed to evaluate the clinical features, prognostic factors and the results of therapy. One hundred and eighty one evaluable patients were treated with three different chemotherapy regimens consisting of vincristine and prednisolone (Group-A), vincristine, prednisolone and L-asparaginase (Group B-60 patients), and vincristine, prednisolone and adriamycin (Group C-81 patients). Complete remission was achieved in 152 (84%) patients, remission induction being 75 percent, 85 percent and 88 percent in Group A, B and C respectively. At a median follow-up of 36 months the disease free survival for complete responders was 35.5 patient. The disease-free survival for Group A, B and C was 20 percent, 47 percent 34 percent respectively indicating the superiority of a three drug regimen over the conventional two drug regimen. Patients at standard risk in each group had significantly better survival when compared to those at high risk. A 3-drug treatment regimen was superior to the 2-drug regimen and a low initial leucocyte count was an important favourable prognostic factor.
Indian J Cancer 1989 Sep
PMID:Acute lymphoblastic leukemia in childhood: treatment, results and prognostic factors. 263 Apr 28

L-asparaginase, an enzyme with established antileukemic activity, increases the induction rate and duration of remission of acute lymphoblastic leukemia when added to vincristine and prednisone for induction therapy. Enzymes derived from two different bacterial sources (Escherichia coli and Erwinia carotovora) are in common use. These enzymes may be associated with toxic reactions of differing frequency and severity. Specifically, the complication of enzyme-induced hyperglycemia may be seen more frequently after exposure to the E. coli product. The authors present two patients in whom it was necessary to substitute the Erwinia enzyme for the E. coli enzyme because of the occurrence of severe allergic reactions to the E. coli enzyme. Hyperglycemia induced by the first product improved after the substitution, suggesting that the Erwinia enzyme may be less diabetogenic than the E. coli enzyme.
Cancer 1989 Feb 01
PMID:Attenuation of asparaginase-induced hyperglycemia after substitution of the Erwinia carotovora for the Escherichia coli enzyme preparation. 264 58

Thirty-four children after multiple relapse or with refractory acute lymphoblastic leukemia were treated with two novel combinations of high-dose cytosine arabinoside, methotrexate, asparaginase, vincristine, and prednisone. The first combination was given to 19 patients. Oncolytic response and marrow hypoplasia was achieved in all. There were four early infectious deaths. Thirteen of the remaining 15 (87%) in whom the response to therapy could be evaluated achieved complete remission. Two achieved good partial remissions. The median duration of complete remission and survival on study was 8 and 10 months, respectively. The four proven and three suspected fungal infections seen in the initial 19 patients was the major toxicity observed. The therapy was modified in the last 15 patients to retain efficacy while reducing the period of neutropenia from a median of 28 to 22 days. No deep-seated fungal infections were seen in these patients. Twelve (80%) achieved a complete remission. Three had an oncolytic response without achieving remission. Eighty-three percent of the 30 evaluable patients, or 74% of all patients entered on study, achieved remission. It is anticipated that the therapy described here will not only achieve another remission in the majority of patients with advanced ALL but that the patients will be able to proceed to alternate therapies with potentially more durable benefit.
Cancer 1989 Apr 15
PMID:Reinduction therapy for advanced or refractory acute lymphoblastic leukemia of childhood. 264 73


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