Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound   Target Concepts: 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)

It has previously been shown that subchronic and acute administration of L-asparaginase and glutaminase inhibitors D-Aspartic acid (D-ASP) and prolyl-leucyl-glycinamide (PLG) intensifies and attenuates morphine (M) physical dependence, respectively, by the inhibition of ASP and glutamic acid (GLU) production, and subsequently their normal releases. Tizanidine (TIZ) has long been known to be an alpha 2-adrenoceptor agonist and inhibitor of ASP and GLU release. Therefore, in this study TIZ has been administered subchronically during the development of M physical dependence to rats in which M-containing pellets had been implanted or acutely 30 min before naloxone (NL)-induced abstinence syndrome. The subchronic administration of TIZ intensified NL-precipitated abstinence syndrome whereas its acute administration attenuated it, as did D-ASP and PLG. On the other hand, TIZ added into the medium prevented the in vitro M-dependent-made guinea pig ileum from contracting following NL application. Furthermore, TIZ stopped the already started contraction by NL of the M-dependent ileum, which completely relaxed later. These effects of TIZ on M-dependent ileum were antagonized by the alpha 2-adrenoceptor antagonist yohimbine. The intensification by subchronic TIZ administration of abstinence syndrome was attributed to the lesser release of ASP and GLU, which resulted in the larger blockade of M of ASPergic/GLUergic receptors due to the lesser release of their endogenous agonist ASP and GLU and consequently the higher upregulation of the receptors. The attenuation by acute TIZ administration of NL-precipitated abstinence syndrome was explained with lesser release of ASP and GLU and concomitantly the lesser stimulation of the receptors.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Effects of tizanidine on morphine physical dependence: attenuation and intensification. 135 95

A 48-year-old female received serial combination chemotherapy including L-asparaginase (L-ASP) for acute lymphoblastic leukemia. After administration of L-ASP, the prothrombin time and activated partial thromboplastin time were prolonged, while fibrinogen and antithrombin III levels markedly decreased, so she was given fresh frozen plasma (FFP). But subsequently, she developed cerebral infarction in the left parietal region and further hemorrhagic infarction in the right parietal region, and died. Autopsy revealed superior sagittal sinus thrombosis and bilateral cerebral infarction, but no obvious thrombus in other organs. Coagulopathy following L-ASP therapy is well-known. In this case, the coagulation studies at the first attack showed that the plasma protein levels of coagulation and fibrinolysis factors decreased in spite of administration of FFP. Fibrin-fibrinogen degradation products (FDP) slightly increased. However there were no significant abnormalities in the platelet count, nor soluble fibrin monomer, which suggested no evidence of disseminated intravascular coagulation. Thus, these findings suggest that L-ASP might be associated with the pathogenesis of thrombosis in this case.
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PMID:[Superior sagittal sinus thrombosis following L-asparaginase therapy of acute lymphoblastic leukemia]. 157 39

Lymphoblasts from 21 previously untreated patients with acute lymphoblastic leukemia (ALL) and 31 patients in relapse were tested for chemosensitivity. Blast cells were cultured with 22 anticancer drugs for 4 days and assayed by MTT dye using a scanning microplate photometer. The percent cytotoxicity index (%CI) and LD50 (micrograms/ml) were calculated for each drug. The mean absorbances (+/- S.D.) of 1 x 10(5) cells in the untreated group and relapsed groups in control wells were 0.219 (+/- 0.126) and 0.385 (+/- 0.147), respectively (p less than 0.01). Cells in the untreated group were more sensitive in vitro to vincristine, prednisolone, L-asparaginase (L-ASP), vinblastine, 5-fluorouracil, epirubicin, bleomycin (BLM), and etoposide (VP16) with respect to the %CI value and to L-ASP, VP16, BLM, and mitoxantrone with respect to the LD50 value than those in the relapsed groups. In contrast, no significant differences were observed for the other 13 drugs. There was also a significant difference in sensitivity within the relapsed group--13 having good clinical response and 15 showing no response to chemotherapy--with regard to four drugs, mitomycin C, neocarzinostatin, L-ASP, and teniposide. Cells in the relapsed group had more heterogeneous chemosensitivity than those in the untreated group, and divided into sensitive and resistant types, but large interindividual differences existed. The MTT assay and LD50-drug resistance percentile curves are useful for the selection of effective drugs in both untreated and relapsed patients with acute leukemia.
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PMID:In vitro chemosensitivity of lymphoblasts at relapse in childhood leukemia using the MTT assay. 174 57

The role of L-asparaginase (L-ASP) in limiting signs of methotrexate (MTX) toxicosis was studied. Eight dogs were randomly allotted to 2 groups of 4 dogs. All dogs were given 400 IU of L-ASP/kg of body weight IM, on day 1. On day 10, group-1 dogs were given 3 mg of MTX/kg, IV, and group-2 dogs were given 6 mg of MTX/kg, IV. All dogs were given 400 IU of L-ASP/kg, IM, 24 hours later (on day 11). One group-2 dog was euthanatized on day 16 because of severe gastrointestinal signs that were unresponsive to treatment. A second dose of MTX, identical to that given on day 10, was given on day 20 to each surviving dog, followed by L-ASP on day 21. On day 67, the 7 surviving dogs were given 3 mg of MTX/kg, IV. Adverse reactions observed were vomiting, diarrhea, and weight loss. Gastrointestinal side effects of MTX were not attenuated with L-ASP and would be a serious limitation to use of MTX administered at an intermediate dose in the treatment of lymphoma in dogs.
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PMID:Preclinical evaluation of L-asparaginase and methotrexate administered at intermediate doses in dogs. 176 84

Two patients with hematological malignancies were successfully treated with monomethoxypolyethylene glycol-conjugated Escherichia coli L-asparaginase (PEG2-ASP), which reportedly lacks both antigenicity and immunogenicity but retains catalytic activity as well as slow clearance in an experimental animal model. A 20-year-old male patient with leukemic lymphoma was refractory to conventional chemotherapy but responsive to L-asparaginase (L-ASP) followed, however, by severe adverse effects. On relapse, an intravenous infusion of 100-200 IU/day dose of PEG2-ASP alone led to a complete remission 2 months later without hypersensitivity or other significant adverse reactions. Surprisingly, he remained in a complete remission for over one year with a regular weekly infusion of PEG2-ASP, combined with a weekly small dose of Ara-C. During this period, blood asparagine was not detectable. The other patient, a 64-year-old woman with chronic myelogenous leukemia in blast crisis achieved, within 6 weeks, a complete remission with twice-weekly infusions of PEG2-ASP. Thus, PEG2-ASP is a highly effective antitumor agent overcoming the limitations in therapeutic use of L-ASP.
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PMID:High efficacy of monomethoxypolyethylene glycol-conjugated L-asparaginase (PEG2-ASP) in two patients with hematological malignancies. 186 35

The inhibition by opiates and the sudden normalization by opioid antagonists of the brain L-asparaginase activity (BAA) have previously been reported to be the main factors in the development of physical dependence and the manifestation of precipitated abstinence syndrome, respectively. As a result, L-asparaginase inhibitors D-aspartic acid and prolyl-leucyl-glycinamide (PLG) were separately given to mice and rats either just after morphine (M)-containing pellet implantation or 15 min before naloxone (NL)-precipitated abstinence syndrome. The animals treated in this manner were used to assess the intensity of the physical dependence and to determine the BAA. D-ASP or PLG administration following pellet implantation significantly increased all of the observed signs such as flying, jumping, wet dog shake and writhing. When D-ASP or PLG were given 15 min before precipitated abstinence they significantly decreased the number of the signs. The determination of the BAA showed significant decreases or increases more or less parallel to the severity of the physical dependence on M. The intensification of physical dependence by D-ASP or PLG given just after the pellet implantation was attributed to their additional inhibitory effect to that of M on the BAA at the beginning of the physical dependence development. The attenuating effect of BAA inhibitors D-ASP or PLG administered before precipitated abstinence was explained with the prevention of the increase in the BAA.
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PMID:Intensification and attenuation of morphine dependence by D-aspartic acid and PLG. 196 65

The development of physical dependence on opiates appears to involve an inhibition by opiates of L-asparaginase and glutaminase, and the blockade by opiates of aspartatergic (ASPergic)/glutamatergic (GLUergic) receptors. Ketamine (K) (0.5 or 1 mg/kg) or dextromethorphan (DM) (1 or 2 mg/kg), both of which are known to decrease the responsiveness of ASPergic/GLUergic receptors, were administered to the three morphine (M)-containing pellets implanted rats prior to 2 mg/kg naloxone (NL) injection. Whereas 0.5 mg/kg K showed no significant effect on abstinence syndrome signs, 1 mg/kg K and 1 mg/kg DM significantly attenuated some of the signs. The attenuation or prevention of all the signs were observed after 2 mg/kg DM administration. Almost complete prevention was seen from the second minute on during the ten-minute observation period. As ASP and GLU antagonists K and DM have this antagonizing effect on the precipitated abstinence syndrome signs, the manifestation of abstinence syndrome may mainly result from the normalization of ASP and GLU production because of the disinhibition by NL of the enzymes and the stronger stimulation of ASPergic/GLUergic receptors which have no opiate blockade after NL injection.
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PMID:Suppression by ketamine and dextromethorphan of precipitated abstinence syndrome in rats. 234 61

Thirteen children with acute lymphoblastic leukemia (ALL) were investigated before and during cytotoxic therapy. EEG findings were correlated with the clinical course and the therapy protocol and compared with normal data obtained from 295 healthy children. Frequency analysis of the background activity of the EEG revealed an initial slowing of the background activity prior to therapy and further slowing each time a combination of vincristine (VCR), daunorubicin (DAU) or adriblastine (ADR), prednisone (PRED), and L-asparaginase (L-ASP) was administered. The slowing of the background activity correlated only with the administration of these drugs. DAU, ADR, and PRED are not known to influence the EEG; therefore, VCR and L-ASP remain the primary candidates responsible for the central nervous system alteration.
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PMID:Changes in the EEG background activity of children with acute lymphoblastic leukemia during cytotoxic therapy. 315 16

By using a modification of the microtiter solid-phase radioimmunoassay, we have measured Escherichia coli L-asparaginase (L-ASP) specific IgG, IgG4, and IgE antibodies in children who received L-ASP as part of their chemotherapy for leukemia and lymphoma. In 13 children with acute lymphoblastic leukemia induced with vincristine, prednisone, and L-ASP (10,000 IU/M2 i.v. each week for 3 weeks), seven developed high titer specific IgG antibodies. Four of the seven relapsed at the time of their peaking IgG response (6-10 months). None of the six with low or absent L-ASP antibody response have relapsed (followed for 20-35 months). In six children with allergic reactions to L-ASP reinduction, all had high titers of L-ASP specific IgG4 (greater than or equal to 20 U/ml) at the time of their reaction. In 16 other children with low L-ASP IgG4 (less than 13 U/ml), none demonstrated allergic reactions to rechallenge. Specific IgE was not consistently detectable in either group. In 21 patients with leukemia or lymphoma on L-ASP with cyclophosphamide-containing regimens, none developed significant IgG antibody response, compared with seven of 13 not receiving cyclophosphamide (p less than 0.001). We conclude: (a) development of L-ASP antibodies may have prognostic significance; (b) the detection of specific IgG4 can predict L-ASP allergy; and (c) cyclophosphamide-containing regimens reduce antibody formation to L-ASP and may allow repetitive (without anaphylaxis) and more effective (avoiding neutralizing antibodies) use of L-ASP.
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PMID:Antibody response to Escherichia coli L-asparaginase. Prognostic significance and clinical utility of antibody measurement. 352 39

Thirty patients with advanced acute leukemia and lymphoma were treated with the sequential combination of high dose ARA-C (HiDAC 3 gm/m2 infused i.v. over 3 h at 0, 12, 24, 36 h) and asparaginase (ASP 6.000 IU/m2 i.m. at hour 42). The sequence was given on day 1 and 8 irrespective of the degree of myelosuppression. Of 22 patients with leukemia there was only one who was absolutely refractory to therapy. Complete remission was induced in 3 patients with ANLL (30%) and in 3 with ALL (30%). Three patients became hypoplastic but recovered with blasts and 12 died from infection, complicated by intracranial hemorrhage in 3, during hypoplasia. Of 8 patients with lymphoma, 2 were clearly refractory to therapy, one died from sepsis and the remaining 5 all entered remission (2 CR + 3 PR, 62%). Activity of HiDAC/ASP against CNS disease is suggested by the clinical response seen in patients with overt meningeal or intracerebral involvement. Toxicity associated with HiDAC/ASP was mainly hematologic. All but one patient experienced hypoplasia and severe pancytopenia; documented infections and major hemorrhages occurred in 80 and 20% of patients respectively. We conclude that HiDAC/ASP is a regimen with definite activity against acute leukemia and lymphoma including CNS disease. Alternate treatment schedules should be explored in order to reduce marrow toxicity.
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PMID:Sequential combination of high dose ARA-C (HiDAC) and asparaginase (ASP) for the treatment of advanced acute leukemia and lymphoma. 647 2


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