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

Thirty previously untreated adults with diffuse histiocytic and diffuse undifferentiated lymphoma were treated with a combination of adriamycin, vincristine, prednisolone, and L-asparaginase. Complete remission was achieved in 11 out of 12 cases with stage III and 7 out of 18 cases with stage IV disease (P less than 0.005). Bone marrow infiltration, clinical central nervous system involvement, and massive intra-abdominal disease all influenced the prognosis adversely. Complete remission was followed by cranial irradiation and intrathecal methotrexate, and maintained with weekly cyclophosphamide and methotrexate and daily 6-mercaptopurine. The duration of remission was significantly longer for patients with stage III disease (the median of which has not been reached), than for patients with stage IV disease (P = 0.007). Survival was significantly longer for patients in whom complete remission was achieved than for those in whom it was not (P = 0.001), and also for patients with stage III than for those with stage IV disease (P = 0.02).
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PMID:Combination chemotherapy for advanced non-Hodgkin's lymphoma of unfavourable histology. 37 11

L-Asparaginase, in the dose of greater than or equal to 6000 IU/sq m three times weekly, was demonstrated to be an effective agent in reinduction of remissions in childhood leukemia. Four hundred thirteen children with acute lymphocytic leukemia were treated with L-asparaginase. Doses i.m. ranged from 300 to 12,000 IU/sq m. None of the patients had received prior asparaginase therapy. 6-Mercaptopurine was given p.o. concurrently. All of the patients had experienced several previous relapses, and their disease was not responsive to 6-mercaptopurine. L-Asparaginase was found to be effective in reinducing remissions at the following rates: 9.5% for 300 IU/sq m; 35.1% for 3,000 IU/sq m; 53.5% for 6,000 IU/sq m; and 62.5% for 12,000 IU/sq m. The drug was given three times weekly for four weeks. Hypersensitivity reactions occurred in 6.5% of patients.
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PMID:Effective dose of L-asparaginase for induction of remission in previously treated children with acute lymphocytic leukemia: a report from Childrens Cancer Study Group. 38 78

Second remission induction rates for vincristine and prednisone alone (VP) and vincristine, L-asparaginase, and prednisone (VLP) are compared for children with acute lymphocytic leukemia. No evidence of a significant difference between the second induction complete remission rate for VP (78.6%) and VLP (73.7%) was found. Duration of first remission and prognostic group at initial diagnosis (defined on the basis of age and white blood count at initial diagnosis) are shown to be significant prognostic factors for second remission induction; and three second remission induction risk groups are defined on the basis of these two factors. Periodic reinforcement with prednisone in first remission does not appear to lower second induction complete response (CR) rates for VP. There was no evidence of a significant difference in the frequency of occurrence of severe toxicity between the VP and VLP regimens.
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PMID:Vincristine and prednisone vs vincristine, L-asparaginase, and prednisone for second remission induction of acute lymphocytic leukemia in children. 38 87

Earlier work has shown that 5-diazo-4-oxo-L-norvaline (DONV) irreversibly inactivates the L-asparaginase from E. coli by formation of a covalent bond in the region of the active site. Model compounds have been prepared to study this acid-labile covalent bond tentatively assigned to a serine or possibly a threonine residue in a decapeptide isolated from 14C-DONV-inactivated enzyme. Appropriately blocked DONV was found to alkylate methanol, and the hydroxyl function of blocked serine or threonine in the presence of boron trifluoride. The labile beta-ketoethers thus formed were reduced to the more stable beta-hydroxyethers. Facile lactonization of these 5-substituted-4-hydroxy-L-norvalines was observed. The diastereoisomers of both the lactonized and open forms of 5-methoxy-4-hydroxy-L-norvaline and related 4-hydroxy-L-2-amino acids of similar length were distinguishable on the amino acid analyzer. The beta-hydroxyethers derived from serine and threonine were hydrolyzed with acid and yielded the expected cleavage products. When the beta-ketoether was reduced by sodium borohydride prior to deblocking, in addition to the beta-hydroxyether, N-blocked amino alcohols were also formed, yielding a complex mixture of products.
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PMID:Synthesis of model compounds relevant to the active-site-directed inactivation of L-asparaginase by 5-diazo-4-oxo-L-norvaline. 38 21

S-Carboxymethylated L-asparaginase was digested with trypsin and the resulting peptides were isolated by using gel filtration, ion exchange column chromatography and paper chromatography. Among the peptides thus isolated, 27 peptides were considered not to overlap and the sum of the amino acids from these 27 peptides is in good agreement with amino acid composition of the enzyme. The amino acid sequences of the peptides were determined by fragmentation with various enzymes and subtractive Edman degradation.
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PMID:Amino acid sequences of the tryptic peptides from carboxymethylated L-asparaginase from Escherichia coli. 38 70

At the present time, a successful regimen for the eradication of occult meningeal leukemia, following induction of a first complete remission in acute lymphoid and undifferentiated childhood leukemia, is the combination of cranial radiotherapy in a dose of 1800 rads in 10 fractions in 12--14 days with six doses of intrathecal methotrexate. This regimen, when given with prednisone and vincristine with or without L-asparaginase for induction and daily oral 6-mercaptopurine and weekly methotrexate for maintenance, can be expected to give a relapse rate for isolated meningeal leukemia of approximately 5% during the first 2 years of follow-up. A modification of this regimen utilizing craniospinal radiation with prior and concurrent intrathecal methotrexate is given for the treatment of overt meningeal leukemia at diagnosis or for an isolated first relapse with meningeal leukemia. Radiation technique and morbidity are discussed.
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PMID:Radiation in the treatment of meningeal leukemia. 39 92

Specific L-asparaginase activity and non-specific cytotoxicity of asparaginase-glutaminase preparation from Pseudomonas fluorescens were studied. Two cell lines, i.e. the asparaginase-dependent (Berkitt lymphoma cells) and the asparaginase-independent (the ovary cancer cells) were used as the test-system. Incorporation of 3H-timidine into DNA was used as the criterion of the drug effect on the cells. Krasnitin was used as the reference preparation. The preparation of asparaginase-glutaminase was inferior to krasnitine by its specific antitumour asparaginase activity and superior to it by the general cytotoxicity in the cells of CaOv. With the help of the above test-system it is possible to study the specific asparaginase activity of the drugs containing L-asparaginase. For studying the specific glutaminase properties it is necessary to develop another cell test-system.
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PMID:[Biological properties of an asparaginase-glutaminase preparation from Pseudomonas fluorescens in cell cultures]. 41 58

13 children affected by acute lymphoblastic leukemia in advanced stage of illness received a sequential therapy with daunorubicin and L-asparaginase. During daunorubicin therapy a significant decrease of bone hypercellularity as well as circulating cells occurred, a further cycle with a scarcely myelotoxic drug, L-asparaginase, was administered: a 10/13 (76.9%) remission of the disease was then achieved. This therapeutic trial was well accepted and could be more extensively used in the patients in relapse. A remission lasting between 4 and 28 weeks was observed.
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PMID:Sequential therapy with daunorubicin and L-asparaginase in relapses of acute lymphoblastic leukemia in children. 41 42

Depletion of circulating L-asparagine has proved beneficial in the treatment of some acute lymphoyctic leukemias. To avoid the immunologic sequelae of administering L-asparaginase parenterally, we have covalently attached the enzyme to the outside of the fibers of a conventional hollow fiber hemodialyzer. This provides ready access of the substrate to the enzyme, while simultaneously isolating the foreign protein from the immune system. Such reactor-dialyzers perform well, both in vitro and in vivo. Circulating L-asparagine in the healthy dog is reduced from about 50 micrometer to less than 2 micrometer within 30 min of connecting the reactor-dialyzer and the reduction persists for at least 4 hr after cessation of treatment.
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PMID:A new extracorporeal reactor-dialyzer for enzyme therapy using immobilized L-asparaginase. 43 2

The L-cyst(e)ine requirements of normal and malignant cells are reviewed and expanded within the context of establishing whether the measurement of gamma-cystathionase levels constitutes a predictive test for tumor sensitivity to L-cyst(e)ine depletion. The ability of both purified L-cysteine desulfhydrase and gamma-cystathionase to inhibit the growth of the L-cystine-dependent L1210 leukemia in culture is presented, as well as approaches to circumvent the limitations of these enzymes for in vivo therapy. The ability of proparagylglycine to inhibit L-cysteine biosynthesis in vivo is reviewed for its possible use in combination therapy. In addition, the ability of poly D,L-alanine modification of Escherichia coli L-asparaginase to increase the plasma half-life in mice tenfold as well as to decrease the immunogenicity of the enzyme is presented.
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PMID:L-cyst(e)ine requirements of malignant cells and progress toward depletion therapy. 46 47


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