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)

Changes in the coagulation system due to steroids and asparaginase during treatment for acute lymphoblastic leukemia (ALL) are well known side effects and may cause bleeding or thrombosis. We report the case history of a 7-year old girl who developed thrombosis of the sinus sagittalis superior during ALL-treatment. Diagnosis was made by computed tomography and magnetic resonance imaging after the child became symptomatic with seizure. Until this event the girl had been treated already for two weeks with prednisone and E. coli-asparaginase (4 infusions). This medication caused distinct hypofibrinogenemia (Fibrinogen 53 mg/dl), prothrombin time expressed as percent of normal values of 58% was also pathological, activated partial thromboplastin time of 35 sec, antithrombin III 120% and thrombocyte count 178 G/l were in normal range. We were not successful in the attempt to adjust the imbalance in the coagulation system by transfusion of fresh frozen plasma (FFP)--seizure happened during FFP-infusion, fibrinogen blood level could be elevated only slightly. Our patient stayed consequently asymptomatic, the clinical recovery was confirmed radiologically.
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PMID:[Venous thrombosis of cranial sinuses in asparaginase therapy. A case report]. 796 36

A randomized study was done in twenty newly diagnosed children with acute lymphoblastic leukemia. Ten children were treated with Escherichia coli L-asparaginase, and ten with Erwinia chrysanthemi L-asparaginase. L-asparaginase (ASP) treatment started halfway during ALL-induction treatment with vincristine, prednisone, daunorubicin and intrathecal methotrexate. The mean activated partial thromboplastin time (APTT) level in all children demonstrated a significant fall (P < 0.001) from 28.25 sec at diagnosis to 23.0 sec at the start of ASP treatment. In this same time interval, the mean fibrinogen level declined markedly from 3 g/l to 1.2 g/l (P < 0.001), probably due to prednisone therapy. The APTT stayed shortened during ASP therapy, whereas the hypofibrinogenemia recovered significantly faster in the Erwinia group (P < or = 0.01). Factors (F) II, V, VII and X stayed within the normal range, while F VIII and F IX were elevated. During the entire period of induction therapy, the ATIII activity remained within the normal range in both treatment groups. The protein C values, however, demonstrated a steady decline from 140% at start of ASP treatment to a mean of 81% and 93%, respectively, at the end of the ASP therapy in the E. coli and Erwinia group. Five of the ten children treated with E. coli ASP demonstrated protein C levels below 70% at the end of ASP therapy, opposed to none of the Erwinia treated patients (P = 0.03). We suggest that the effect of ASP resulting in decreased coagulation factor synthesis is in part counterbalanced by the effect of prednisone on the coagulation system, when ASP is administered at the end of ALL induction treatment. The overall effect of ASP either of E. coli or of Erwinia on the hemorrhagic system reveals a slight imbalance towards thrombosis, mainly because of a gradual decrease in protein C activity. This imbalance is less pronounced in the Erwinia group.
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PMID:Minimal effects of E. coli and Erwinia asparaginase on the coagulation system in childhood acute lymphoblastic leukemia: a randomized study. 805 4

Unfractionated heparin has been used as antithrombotic therapy for many years. Its main effect is attributed to the activation of antithrombin (AT), the heparin/AT complex inactivating both factor IIa (thrombin) and factor Xa. Resistance to unfractionated heparin with clinical or biological expression is uncommon. The occurrence of venous or arterial thrombosis or the extension of thrombosis in a patient receiving unfractionated heparin, should always raise suspicion of either AT deficiency or type 2 heparin-induced thrombocytopenia (HIT type 2). HIT type 2 is not a true heparin resistance but an immune complication that requires heparin discontinuation and the use of alternative anticoagulants. Biological heparin resistance is suspected in the presence of a normal or not prolonged activated partial thromboplastin time despite the administration of increasing dose of heparin. Measurement of anti-Xa activity is useful to adjust heparin treatment. Isolated biological heparin resistance is encountered in several physiological and pathological situations including inflammatory and infectious disorders, pregnancy and thrombocytosis. It also occurs in acquired antithrombin deficiency of nephrotic syndrome, l-asparaginase treatment or cardiopulmonary bypass. Biological heparin resistance is relatively common, but clinically significant resistance to heparin is rare and should always raise suspicion of either AT deficiency or type 2 heparin-induced thrombocytopenia.
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PMID:[Resistance to curative treatment by unfractionned heparin]. 1881 40

The phenomenon of heparin resistance (HR) is characterized by high doses of unfractionated heparin (UFH) being required to bring activated partial thromboplastin time (aPTT) and activated coagulation time (ACT) within therapeutically desired ranges, or by the impossibility of reaching these ranges. At UFH dosages > 35,000 IU/d, HR should be considered a factor. The most frequent cause of HR is deficiency of antithrombin (AT), the presence of which is essential for UFH to exert its anticoagulatory effect. AT in concentrate form may be applied to overcome AT-dependent HR. The main clinically relevant situations in which AT-dependent HR occurs, with possible indication of AT substitution, are congenital AT deficiency, asparaginase therapy, disseminated intravascular coagulation (DIC) and administration of high doses of heparin during extracorporeal circulation, where it is significant, due to the need to maintain a very high ACT (> 400 s), that use of heart-lung machines is associated with an HR incidence of approximately 20%. The following procedure is recommended when there is no DIC and when extracorporeal circulation is not used: if HR is suspected and AT activity is < or = 60%, UFH should first be reduced to 500 IU/h (to prevent bleeding complications), before AT is substituted. AT activity should then exceed 80%. Under normalized and stable AT activity, the UFH dose should be adjusted such that aPTT is within a range of 60-100 s. If anticoagulation over a longer term is indicated, then overlapping anticoagulation with a vitamin K antagonist should be started as quickly as possible.
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PMID:[Heparin resistance and antithrombin deficiency]. 1953 51

Nasal-type extranodal natural killer (NK)/T-cell lymphoma (ENKL) is a highly invasive cancer with a poor prognosis. More effective and safer treatment regimens for ENKL are needed. Pegaspargase (PEG-Asp) has a similar mechanism of action to L-asparaginase (L-Asp), but presents lower antigenicity. The aim of the present research was to evaluate the safety profile and the latent efficacy of a PEG-Asp-based treatment regimen in patients with ENKL. Data collected from 20 patients with histologically confirmed ENKL, admitted to the Third Affiliated Hospital of Sun Yat-Sen University from January 2009 to August 2013, were included in the study. All patients received 2500 IU/m2/IM PEG-Asp on day 1 of every 21-day treatment cycle. Patients received combination chemotherapy with CHOP (n=5), EPOCH (n=7), GEMOX (n=7) or CHOP with bleomycin (n=1). After 2-5 treatment cycles (median, 4 cycles) of PEG-Asp-based chemotherapy, five patients (25%) showed a complete response (CR), and the overall response rate (ORR) was 60%. Grade 3/4 neutropenia occurred in fourteen patients (70%). Grade 3 alanine aminotransferase (ALT) elevation was observed in two. Grade 1-2 non-hematological toxicity consisted of activated partial thromboplastin time (APTT) elongation (n=9), hypofibrinogenemia (n=6), hypoproteinemia (n=17), hyperglycemia (n=3), and nausea (n=6). No allergic reactions were detected. No treatment related death was reported. Our results suggested that PEG-Asp-based chemotherapy presented an acceptable tolerance and a potential short-term outcome in patients with nasal-type ENKL.
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PMID:Efficacy and tolerance of pegaspargase-based chemotherapy in patients with nasal-type extranodal NK/T-cell lymphoma: a pilot study. 2512 11

Heparin resistance can be defined as high doses of unfractionated heparin (UFH), greater than 35,000 IU/day, required to raise the activated partial thromboplastin time (aPTT) and activated coagulation time (ACT) to within therapeutically desired ranges or the impossibility of doing so. The most common pathology responsible is the deficiency of anti-thrombin III (ATIII) deficiency. Other clinically relevant conditions that can present with heparin resistance are congenital deficiencies; use of high doses of heparin during extracorporeal circulation, use of asparaginase therapy and disseminated intravascular coagulation (DIC). Most of these conditions effect the ATIII levels. Patients are typically identified in an acute phase, when determination of the cause of resistance is challenging. We present a case where a patient presented with suspected heparin resistance in an acute phase of sickness, where timely intervention was able to prevent a potentially fatal situation. Abbreviations: Neuroendocrine tumors (NETs), World health Organization (WHO), Radiation therapy (RT).
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PMID:To be or not to be a case of heparin resistance. 2991 55


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