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)

Dural sinus thrombosis (DST) has been reported in association with cancer in both adults and children. We describe the seven patients seen with this complication in our centre between 1981 and 1995. Diagnosis was confirmed by either cerebral CT scanning, MRI or angiography. Median age was 13 years (range 8-15). Six patients were boys. Six children were being treated for non-Hodgkin lymphoma and one for neuroblastoma. Presenting symptoms were seizures and transient neurologic deficit, often preceded by headaches. The probable cause of DST was found in two cases. Tumour localisation in the central nervous system (CNS) probably caused DST in one patient who was treated for ki 1 lymphoma. Dehydration in combination with a poor general condition seemed to be the cause of DST in the patient with neuroblastoma. In five children with stage III or IV non-Hodgkin lymphoma (three lymphoblastic lymphoma; two Burkitt's lymphoma), etiology remained unknown. In these children, DST occurred early in the course of therapy. The median interval between start of chemotherapy and onset of symptoms was 19 days (range 8-40). No child had received L-asparaginase. Prognosis was favourable, with symptoms completely disappearing without therapy within 1 to 5 days. The incidence of DST in patients with advanced stage non-Hodgkin lymphoma during induction and consolidation was calculated to be below 3%. We conclude that DST is rarely diagnosed in children with cancer. Occurrence during the initial phase of therapy for non-Hodgkin lymphoma is associated with a benign prognosis.
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PMID:Dural sinus thrombosis in children with cancer. 1211 89

L-Asparaginase is the major induction-phase agent for treatment of acute lymphoblastic leukemia (ALL) and an important adjuvant in treatment of non-Hodgkin's lymphoma (NHL). However, L-asparaginase-induced disturbances of clotting homeostasis may result in thrombosis or hemorrhage. Thrombotic occlusion of small cerebral veins has been reported in patients with ALL treated with this agent, but have not been described in NHL patients or those treated with the long-acting synthetic congener, pegaspargase. We report a 16-year-old boy with NHL who developed a focal motor seizure 15 min after receiving intravenous pegaspargase. MRI of the brain demonstrated multiple cortical and subcortical lesions that most likely represented focal brain edema due to thrombotic venous occlusion, which improved remarkably within 3 days and completely resolved within 3 weeks without specific intervention or permanent clinical consequences. This process must be considered when such changes are detected in NHL patients.
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PMID:Reversible MRI lesions due to pegaspargase treatment of non-Hodgkin's lymphoma. 936 5

Reversible posterior leukoencephalopathy syndrome (RPLS) is being increasingly described with various etiologies even in the absence of hypertension. We present an 11-year-old patient with acute lymphoblastic leukemia who presented with seizures while on treatment with L-asparaginase. MRI showed bilaterally symmetrical nonenhancing occipital lesions characteristic of RPLS. L-Asparaginase-induced RPLS is a rare cause of neurological symptoms in patients on induction chemotherapy.
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PMID:L-asparaginase-induced reversible posterior leukoencephalopathy syndrome in a child with acute lymphoblastic leukemia. 1237 14

Coagulation disorders are common in cancer patients. In patients with solid tumors, a low-grade activated coagulation can result in systemic and cerebral arterial or venous thrombosis. Cancer treatments may also contribute to this coagulopathy, which usually, but not exclusively, occurs in the setting of advanced malignant disease. There may be TIAs or cerebral infarctions. Because of the widespread distribution of cerebral thromboses, there may be a superimposed encephalopathy; sometimes this is the only sign. Concurrent systemic thrombosis is present in many patients and is a useful clue to the diagnosis. In cerebral venous occlusion, the initial symptom is usually a headache. Except for cerebral intravascular coagulation that is unassociated with NBTE, neuriomaging studies usually demonstrate one or more parenchymal infarctions. MRI or MRV may demonstrate venous thrombosis. The laboratory evidence of coagulopathy is difficult to distinguish from the asymptomatic coagulopathy that often accompanies advanced cancer, and the test results must be interpreted cautiously. NBTE can be diagnosed by transesophageal echocardiography. There is no established treatment for the thrombotic coagulopathy associated with cancer, but anticoagulation should be considered. In leukemia and lymphoma, the coagulopathy is typically acute DIC that can lead to systemic and brain hemorrhages. It is especially common in acute myelogenous leukemias. The clinical signs of cerebral hemorrhage are fulminant and may be fatal. The bleeding usually occurs in the brain or subdural compartment, and rarely in the subarachnoid space. The diagnosis can be suspected by the clinical setting and by systemic thrombosis or hemorrhage. It can be established by examination of the peripheral smear, the platelet count, and tests of coagulation function. Therapy of acute DIC is controversial and should be individualized for the clinical setting. Cerebrovascular disorders can complicate metastatic or primary tumor in the brain, skull, dura, or leptomeninges. The clinical signs of infarction are indistinguishable from other causes of stroke, except that tumor-related venous occlusion will usually first produce signs of increased intracranial pressure. The diagnosis of tumor-related infarction can usually be established by neuroimaging studies that show infarction and may show extracerebral sites of tumor. CSF examination is useful in diagnosing leptomeningeal metastasis. A search for lung or cardiac tumor should be performed when embolic tumor infarction is suspected. Primary or metastatic tumors in the brain or dura may hemorrhage, producing the initial clinical signs of the brain tumor or a change in chronic signs induced by the tumor. There are helpful clues to a neoplastic hemorrhage on brain CT or MRI scans. The brain hemorrhage may require evacuation and the underlying tumor will usually require additional antineoplastic treatment. Hyperleukocytosis (extreme elevation of the cell count) in acute myelogenous leukemia is a less common cause of brain hemorrhage in recent years because of improved methods to lower the cell count. Cerebral arterial or venous thrombosis is sometimes the result of cancer therapy. The attribution of thrombosis to chemotherapy in many published cases is only speculative, because carefully conducted prospective studies that include investigation for other thrombotic causes are not available. The best-known associations with thrombosis are L-asparaginase, which is typically used in the induction therapy of acute lymphocytic leukemia, and combination hormonal therapy and chemotherapy for breast cancer. Radiation to the head and neck, typically administered for head and neck epithelial cancers or lymphoma, may result in delayed carotid atherosclerosis. The distribution of stenosis or occlusion is within the radiation portal and is typically more extensive than is atherosclerosis that develops in the absence of radiation. Small clinical series suggest that surgical treatment is equally effective as in nonirradiated carotid atherosclerosis. In children, the cerebral vessels can be affected by brain radiation resulting in stenosis or occlusion. Brain hemorrhages can result from chemotherapy effects on the hemostatic system or a microangiopathic anemia. Hemorrhages from radiation-induced vascular abnormalities are rare. Opportunistic infections, especially fungal infections, can complicate cancer or its treatment. Septic cerebral emboli may result in focal cerebral signs, seizures, or encephalopathy. Sometimes there is an associated hemorrhagic vasculitis or cerebritis. Rarely, mycotic aneurysms may bleed. A high index of suspicion is needed to diagnose fungal infection because of the difficulty in culturing the organism from the blood or CSF. A clinician can usually establish the cause of stroke in the cancer patient by performing a careful review of the clinical setting--including the type and extent of cancer and the type of antineoplastic therapy--in which the stroke occurred. Systemic thrombosis, embolism, or hemorrhage can be a clue to the cause, and appropriate neuroimaging and coagulation studies to aid in the diagnosis are available. Therapy may ameliorate symptoms or prevent further episodes. The identification of one of these unusual stroke syndromes that leads to the diagnosis of an occult and treatable cancer can be particularly rewarding.
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PMID:Cerebrovascular complications in cancer patients. 1269 Jun 49

L-asparaginase is frequently used in combination therapy for the treatment of lymphoid malignancies. We report 5 children aged between 8 and 14 years with neurologic complications presenting with headache and seizures during the first three weeks of L-asparaginase treatment. Three patients had venous thrombosis, one presented a parenchymal hemorrhage, and one showed a peculiar encephalopathy with extended cortical and subcortical lesions suggesting a neurotoxic reaction. Decreased fibrinogen and antithrombin III levels were found. Early MRI is critical even in cases with mild neurologic symptoms. Diagnosis should be followed by early cessation of l-asparaginase application.
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PMID:Cerebrovascular complications of L-asparaginase in the therapy of acute lymphoblastic leukemia. 1279 28

An association has been reported between thrombotic events and the use of L-asparaginase (ASP) in children with acute lymphoblastic leukaemia (ALL). The mechanism for thrombosis is likely related to an acquired antithrombin deficiency. Since a primary prophylaxis using antithrombin concentrates may prevent thrombosis, the PARKAA (Prophylactic Antithrombin replacement in kids with ALL treated with L-asparaginase) study was performed. The objectives of PARKAA were to determine if there was a trend to efficacy and safety of antithrombin treatment as assessed by 1) incidence of thrombosis 2) incidence of bleeding and 3) plasma markers of endogenous thrombin generation as surrogate outcomes for thrombosis. The study was not powered to answer the question of efficacy and safety, but rather to detect a trend. PARKAA was an open, randomised, controlled study in children with ALL being treated with ASP. Children were randomised to receive antithrombin infusions or no antithrombin treatment. All thrombotic events were confirmed using bilateral venography, ultrasound, echocardiography and MRI. The incidence of thrombosis in patients treated with antithrombin was 28% (95% CI 10-46%), compared to 37% (95% CI 24-49%) in the non treated arm. Two minor bleeds occurred in patients in the treated arm, but were not considered to be related to antithrombin. No significant differences were seen in plasma markers by the treatment group. In conclusion, treatment with antithrombin concentrate shows a trend to efficacy and safety. In contrast, there was no difference in surrogate markers for thrombosis. Carefully designed clinical trials are needed to test the efficacy and safety of antithrombin in this population.
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PMID:Trend to efficacy and safety using antithrombin concentrate in prevention of thrombosis in children receiving l-asparaginase for acute lymphoblastic leukemia. Results of the PAARKA study. 1288 62

Erythrocytes are potential biocompatible vectors for different bioactive substances, including drugs. These can be used successfully as biological carriers of drugs, enzymes and peptides. There are currently diverse methods that permit drug encapsulation in erythrocytes with an appropriate yield. The methods most commonly employed are based on a high-haematocrit dialysis procedure, mainly hypo-osmotic dialysis. Erythrocytes loaded with drugs and other substances allow for different release rates to be obtained. Encapsulation in erythrocytes significantly changes the pharmacokinetic properties of drugs in both animals and humans, enhancing liver and spleen uptake and targeting the reticulo-endothelial system (RES). Amongst other applications, erythrocytes have been used for drug-targeting the RES with aminoglycoside antibiotics; the selective transport to certain organs and tissues of certain antineoplastic drugs, such as methotrexate, doxorubicine, etoposide, carboplatin, etc.; the encapsulation of angiotensin-converting enzyme (ACE) inhibitors, systemic corticosteroids, the encapsulation of new prodrugs with increased duration of action, etc. Erythrocytes are also attractive systems in the sense of their potential ability to deliver proteins and therapeutic peptides. Thus, erythrocytes have been used for the transport of enzymes destined for the correction of metabolic alterations as l-asparaginase, alcohol dehydrogenase (ADH) and aldehyde dehydrogenase (AlDH) among others. Erythrocytes have been used successfully as carriers of anti-HIV peptides, such as AZT, nucleoside analogues, antisense oligonucleotides, antineoplastic peptides, erythropoietin, interleukin 3, etc. Amongst other applications, mention may be made of paramagnetic erythrocytes, encapsulation of MRI contrast agents or the study of the metabolism of the red cell. Although erythrocytes have been applied with different uses in human medicine, their deployment is still very limited due to difficulties involving storage, its exposure to contamination and the absence of a validated industrial procedure for its preparation.
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PMID:Drug, enzyme and peptide delivery using erythrocytes as carriers. 1501 30

L-asparaginase is a critical component in the treatment of acute lymphoblastic leukemia in children. It is known to cause coagulation abnormalities, thrombosis and hemorrhage in the central nervous system in addition to vasculitis and hypersensitivity reactions. The purpose of this article is to present the first case-series of posterior reversible encephalopathy syndrome (PRES) associated with L-asparaginase treatment. We report 3 cases of children with acute lymphoblastic leukemia who developed seizures and altered sensorium after L-asparaginase therapy. MRI showed increased T(2) signal intensity predominant in the posterior regions of the brain suggestive of PRES. Two of our patients developed septic shock and deteriorated whereas one patient improved and recovered completely.
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PMID:L-asparaginase-induced posterior reversible encephalopathy syndrome during acute lymphoblastic leukemia treatment in children. 1850 83

Antitumor and immunosuppressant treatment-related neurotoxicity can determine nonspecific clinical syndromes. Exclusion of other possible causes, among which tumor progression, appearance of paraneoplastic disease, renal or hepatic failure, diabetes or hypertension, is relevant. We report clinical and neuroradiological features in five patients with neurotoxic syndromes due to chemotherapy/radiotherapy or immunosuppression in the context of neoplastic disease/organ transplantation. Acute neurological syndrome developed in three patients after methotrexate (MTX), cyclosporine A, and L-asparaginase therapy, respectively. MRI showed posterior reversible encephalopathy in two cases and venous thrombosis with intraparenchymal hematoma in the third patient. Late onset clinical syndrome occurred in the last two patients, treated with MTX or radiation therapy for breast cancer metastasis and pituitary adenoma. Neuroimaging showed brain diffuse abnormalities. Patients affected by tumors suffer from increased risk for treatment-related toxicities. Appearance or worsening of neurological signs and symptoms challenge the clinician to discriminate between CNS involvement by the tumor, toxicity of drugs, parane-oplastic disease and infections. MRI has a key role in differential diagnosis. Close interaction between the neurologist, the oncologist and the neuroradiologist leads to the optimal management of patients.
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PMID:Clinical and radiological features of brain neurotoxicity caused by antitumor and immunosuppressant treatments. 1861 59

Cerebral Sinovenous Thrombosis (CSVT) is a serious complication of L-asparaginase chemotherapy for leukemia in children. Clinical features of headache, altered consciousness, focal neurological deficit, and seizures developing during or immediately after treatment with L-asparaginase should alert the treating physician to the possibility of CSVT. Immediate imaging of the brain should be done using CT and MRI and the veins should be visualized noninvasively by CT and MR venography. We report two children on induction therapy for acute leukemia who presented with seizures, headache, and altered consciousness. Venous infarcts with and without hemorrhage were seen on CT in one patient and the empty delta sign was seen after contrast injection; however, the early changes were missed by CT. MRI detected dural sinus thrombosis relatively earlier in another patient, while the CT findings were equivocal; in this patient, contrast-enhanced MRI showed the empty delta sign and MR venography confirmed absent flow in the superior sagittal sinus, which was diagnostic of sinus thrombosis. Rapid anticoagulation was started with heparin and maintained with warfarin. The child with a unilateral small nonhemorrhagic infarct made a complete recovery while the other, with bilateral hemorrhagic infarcts, did not survive. We stress the importance of early diagnosis of CSVT using CT and MRI in children with leukemia being treated with L-asparaginase; this will permit timely treatment.
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PMID:Sagittal sinus thrombosis due to L-asparaginase. 2104 5


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