We have previously hypothesized that higher systemic exposure to asparaginase may cause increased exposure to dexamethasone, both critical chemotherapeutic agents for acute lymphoblastic leukemia. Whether interpatient pharmacokinetic differences in dexamethasone contribute to relapse risk has never been studied. The impact of plasma clearance of dexamethasone and anti–asparaginase antibody leve...

Escherichia coli contains two L-asparaginase isozymes: L-asparaginase I, a low-affinity enzyme located in the cytoplasm, and L-asparaginase II, a high-affinity secreted enzyme. A molecular genetic analysis of the gene (ansA) encoding the former enzyme has previously been reported. We now present a molecular study of the gene, ansB, encoding L-asparaginase II. This gene was isolated by using oli...

The effect of L-asparaginase on the thyroid gland has not been well documented. We report the first two cases of hyperthyroidism associated with thyroid nodule following L-asparaginase therapy for acute lymphoblastic leukemia (ALL). The thyroid function abnormalities were not severe, short-lived and did not require specific therapy.

Survival times of C57BL/6J X DBA/2J Fj mice, inoculated with LI210 or LSI78Y ascites tumor cells, were monitored following treatment with cytosine arabinoside, L-asparaginase, and 6-azauridine, alone and in combination. Each tumor line was sensitive to cytosine arabinoside. L-Asparaginase produced cures (60-day survivors) in 20 to 30% of L5178Y hosts but was totally ineffective against L1210. 6...

Three human isolates of Vibrio succinogenes produced asparaginase. Apparent Km's were 87,220, and 320 microM. The rate of glutamine hydrolysis was between 2.8 and 3.5% of the rate of asparagine hydrolysis. Asparaginase production was not induced by ammonium ions, and enzyme yields were lower than those obtained with the rumen strain.

SUMMARY The bone marrow of patients with acute lymphocytic leukemia, acute myelogenous leukemia, and metastatic cancer (normal marrow) was evaluated for L-asparagine dependence with the use of the in vitro test of Sobin and Kidd. All of the marrows including the normal ones showed L-asparagine dependence. There was a direct correlation between the concentration of L-asparaginase and depression ...

BACKGROUND The effects of L-asparaginase on hemostasis during induction chemotherapy are less defined in adults than in children. We, therefore, studied the effects of L-asparaginase in adult patients. DESIGN AND METHODS This was a retrospective analysis of 214 patients treated with L-asparaginase (7500 IU/m(2) x 6) for acute lymphoblastic leukemia or lymphoblastic lymphoma. Between day 1 of ...

asparaginase and amylase are widely used enzymes in various industries, which can be produced by endophytic fungi. in this study, the ability of producing these two enzymes in endophytic fungi isolated from six species of thymus has been reported for the first time in the world. among 89 isolates of the test, 34 isolates produced asparaginase among which m24 (fusarium subglutinans) displayed th...

Background L-asparaginase II (asnB), a periplasmic protein commercially extracted from E coli and Erwinia, is often used to treat acute lymphoblastic leukemia. an enzyme that converts L-asparagine aspartic acid ammonia. Cancer cells are dependent on asparagine other sources for growth, when these deprived of by the action enzyme, cancer selectively die. Objective Questions remain as whether asn...

The objective of this study was to isolate halophilic bacteria with the ability to produce intracellular or extracellular L-asparaginase. A total number of 120 halophilic bacteria were isolated from 17 different saline habitats of Iran including salt lakes, wetlands, brine springs and deserts. Among these, 68 were able to grow in the presence of 1.5 M NaCl and 52 demonstrated the ability to gro...