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:3.4.21.6 (thromboplastin)
13,278 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The term antiphospholipid syndrome is used to characterize a complex of clinical and pathologic findings mediated by a group of antibodies formed against a family of antiphospholipids. These antiphospholipid antibodies were originally found in patients with lupus erythematosus in whom the partial thromboplastin time was prolonged and in patients with other autoimmune diseases; subsequently, they have been observed in association with a variety of other conditions, including infections, reactions to drugs, malignant neoplasms, human immunodeficiency virus disease, and as an isolated finding. In recent years, there has been some clarification of the significance of the various tests for antiphospholipid antibodies, including the lupus anticoagulant test and the anticardiolipin antibody tests, in predicting the antiphospholipid syndrome. The mechanism of disease, however, has not been well defined. The most common cutaneous lesion seen in seven patients with lupus anticoagulant and anticardiolipin antibody who have the antiphospholipid syndrome was ulceration due to thrombosis of dermal veins and arteries. Often there is a reactive vascular proliferation around the thrombosed vessels. The presence of primary thrombosis of both veins and arteries in thrombotic disorders is unusual and may provide insight into the mechanism of thrombosis in antiphospholipid syndrome.
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PMID:Cutaneous histopathologic findings in 'antiphospholipid syndrome'. Correlation with disease, including human immunodeficiency virus disease. 211 49

Antiphospholipid antibody syndrome is associated with recurrent thromboembolism and the presence of antibodies directed against negatively charged phospholipids. Despite significant hypercoagulability, patients with the disorder often have elevated baseline activated partial thromboplastin times. Although heparin is indicated for the treatment of acute thrombosis, heparin monitoring is complicated by laboratory test interference. A practical treatment approach involves patient-specific screening for a reagent insensitive to the presence of the inhibitor, and determination of a reagent-specific therapeutic range in seconds that corresponds to heparin serum concentrations of 0.2-0.4 U/ml. Other monitoring methods, including using the patient's baseline activated partial thromboplastin time or using an antifactor Xa activity assay, have not been reported or studied but may offer alternatives for heparin monitoring in patients with coagulation laboratory test interference associated with antiphospholipid antibody syndrome.
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PMID:Heparin monitoring in acute thrombosis associated with antiphospholipid antibody syndrome. 747 7

Several clotting abnormalities have been put forth to explain the thrombotic tendency of the antiphospholipid syndrome, but a possible role for fibrinogen and von Willebrand factor has been poorly investigated. The present cross-sectional retrospective study evaluated the relationship of IgG anticardiolipin antibodies, lupus anticoagulants, fibrinogen and von Willebrand factor with the occurrence of arterial and venous thromboses in patients with antiphospholipid antibodies. Among the clotting assays for the detection of lupus anticoagulant, dilute Russell's viper venom time correlated with a history of venous thrombosis more strongly than activated partial thromboplastin time (p < 0.0002 vs p < 0.009) and was the only test which correlated with a history of arterial thrombosis (p < 0.01), also at low levels of IgG anticardiolipin antibodies (p = 0.003). By regression analysis, and after correction for confounders, serum levels of IgG anticardiolipin antibodies were found to be positively associated with the number of venous events (p < 0.001). Plasma levels of fibrinogen and von Willebrand factor were associated with each other (p < 0.0001; r: 0.48) and with the occurrence of arterial and venous thromboses (p < 0.001). Moreover, plasma levels of fibrinogen and von Willebrand factor in thrombotic patients with antiphospholipid antibodies were significantly higher than those of a control group of thrombotic patients who suffered thrombosis for other reasons (p < 0.0001 and p = 0.0008 respectively). Titres of IgG anticardiolipin antibodies correlated with plasma levels of von Willebrand factor (p < 0.0001; r: 0.42).(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Antiphospholipid antibodies, haemostatic variables and thrombosis--a survey of 144 patients. 748 1

A 22-year-old female presented to the Emergency Department after the acute onset of left hemiparesis. Marked prolongation of the partial thromboplastin time, mild thrombocytopenia, a history of syphilis, and recent spontaneous abortion suggested the diagnosis of antiphospholipid antibody syndrome, an unusual cause of ischemic stroke. This case illustrates the clinical and laboratory features of this uncommon disorder.
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PMID:Antiphospholipid antibody syndrome: an unusual cause of stroke in a 22-year-old female. 759 66

A 51-year-old Caucasian male without previous history of thromboembolic disease developed Coomb's positive haemolytic anaemia, thrombocytopenia, transient paranoid psychosis and bilateral adrenal haemorrhage with primary adrenal failure after surgery for inguinal hernia. The activated partial thromboplastin time was spontaneously prolonged, and lupus anticoagulant and anticardiolipin antibodies were detected. In the absence of criteria for classification of systemic lupus erythematosus (SLE), the entity was classified as a primary antiphospholipid syndrome. Despite the persistence of the serological abnormalities, the patient remains well after substitution with cortisone. Primary adrenal failure due to adrenal haemorrhage can be associated with the primary antiphospholipid syndrome.
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PMID:Primary antiphospholipid syndrome associated with postoperative primary adrenal failure. 762 86

To study whether monoclonal anticardiolipin antibodies (aCL), derived from patients with antiphospholipid syndrome (APS), have similar pathogenic potential, we have employed an experimental model of antiphospholipid syndrome. Monoclonal aCL were produced by the combined method of EBV transformation and somatic cell hybridization of lymphocytes, derived from patients with APS. The monoclonal aCL were used to immunize mice at the footpads and the mice were followed for serological and clinical manifestations of APS. The monoclonal antibody EY2C9, was found to bind weakly to cardiolipin and other phospholipids (i.e. phosphatidyl-serine, phosphatidyl-ethanolamine and phosphatidyl-inositol). The antibody TM1B9, although derived from a patient with SLE and with secondary APS, did not react with phospholipids. Immunization of naive BALB/c mice with EY2C9 was followed by production of sustained high titers of antiphospholipid antibodies associated with prolonged activated partial thromboplastin time (APTT) (46.8 +/- 5.0 s vs. 22.4 +/- 1.7 s, in the non-immunized mice). Mice immunized with TM1B9 had a more moderate titer of antiphospholipid antibodies and did not show prolonged APTT. The pregnant mice, that were immunized with EY2C9, had increased fetal resorption rate (the equivalent of fetal loss in the human) of 36.8 +/- 10% (vs. 2 +/- 4% in mice immunized with TM1B9). Our results confirm that monoclonal aCL, derived from a patient with APS, can have a pathogenic potential, dysregulating the idiotypic network and leading to the development of characteristic signs of APS.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Antiphospholipid syndrome and the idiotypic network. 765 90

Antiphospholipid syndrome (APS) is characterized by recurrent thromboembolic phenomena, recurrent fetal loss and thrombocytopenia associated with high titers of IgG anticardiolipin antibodies and/or lupus anticoagulant. There is an increased platelet aggregation in these patients and thus aspirin was found to be effective in abrogating some of the clinical findings. The purpose of this study was to employ the experimentally induced APS in mice infused with anticardiolipin antibodies, to study the effect of a thromboxane receptor antagonist (BMS, 180, 291) on the various overt manifestations of APS. Experimental APS was induced in pregnant female mice by iv infusion of a pathogenic anticardiolipin antibody (CAM). The mice were then treated daily with 300 micrograms/mouse of BMS. The study group and the untreated group were killed on day 17 of pregnancy. Live and absorbed fetuses and the mean weight of the placentae, fetuses and platelet counts were recorded. BMS treated mice had a significant reduction in fetal resorption rate from 45% to 19.8% and an increase in mean placental and embryo weights (182 vs 104, 1043 vs 721 mg, respectively). In parallel, an increase in platelet count (from 597,100 to 1075,000 platelets/mm3) and decrease in activated thromboplastin time (95 to 44s) was seen. It seems that thromboxane receptor antagonist may be effective in abrogating the diverse manifestations seen in APLS. Increased platelet aggregation may be one of the pathogenetic mechanisms in APS.
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PMID:Effect of long-acting thromboxane receptor antagonist (BMS 180,291) on experimental antiphospholipid syndrome. 784 93

Beta 2-glycoprotein I (beta 2-GPI) binds negatively charged substances and inhibits intrinsic blood coagulation in the presence of ellagic acid-phospholipid suspension. Beta 2-GPI is thought to be an important protein in the reaction between negatively charged phospholipids and anti-phospholipid antibodies which appear in patients with lupus anticoagulant/antiphospholipid antibody syndrome. We prepared a monoclonal antibody against beta 2-GPI purified from human plasma and obtained beta 2-GPI-depleted plasma using a monoclonal antibody-coupled column. Either partial thromboplastin time or the activation of prekallikrein induced by diluted ellagic acid-phospholipid suspension in beta 2-GPI-depleted plasma was not different from that in control plasma. Beta 2-GPI inhibited the intrinsic blood coagulation only when added to control or beta 2-GPI-depleted plasma in excess (more than physiological concentrations). The intrinsic fibrinolysis in beta 2-GPI-depleted plasma induced by dextran sulfate was not impaired and, again, beta 2-GPI inhibited the intrinsic fibrinolysis only when added to control or beta 2-GPI-depleted plasma in excess. These results indicate that both in vitro Actin-induced intrinsic coagulation and dextran sulfate-induced fibrinolytic activities are significantly inhibited by more than physiological concentrations of beta 2-GPI.
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PMID:Ellagic acid/phospholipid-induced coagulation and dextran sulfate-induced fibrinolytic activities in beta 2-glycoprotein I-depleted plasma. 786 69

Patients with antiphospholipid syndrome, whether primary or secondary to systemic lupus erythematosus, may have thrombocytopenia. Their antibodies to anionic phospholipids might bind to phospholipids on the platelet wall but anionic phospholipids are asymmetrically located in the inner leaflet. In addition, antibodies to anionic phospholipids may require beta 2 glycoprotein I (beta 2GPI) as a cofactor in order to bind to phospholipids. In turn, beta 2GPI has high affinity for anionic phospholipids. Loss of this asymmetry occurs upon platelet activation and could thus permit such antibody-beta 2GPI-platelet interaction. We studied this by flow cytometry using purified beta 2GPI-FITC labelled and similarly labelled affinity-purified polyclonal antibodies to cardiolipin or phosphatidylserine (aPL) obtained from sera of patients with primary antiphospholipid syndrome. Five percent of resting platelets were bound by aPL in the presence of beta 2GPI. Such binding increased when we activated platelets with various agonists, reaching 31% with the concurrent use of thrombin and the calcium ionophore A23187. Platelet activation resulted in the expression of GMP140 but this did not correlate with aPL binding. This probably reflects that the expression of GMP140, which depends on their secretion of alpha granules, has different agonist responses and occurs at different times than do microvesicle formation and expression of prothrombinase activity which coincide with the loss of phospholipid asymmetry on the platelet wall. When we studied the binding of purified beta 2GPI we also found that it binds preferentially to activated platelets and that it seems to be a prerequisite for the binding of aPL onto them. Our findings indicate that aPL from patients with antiphospholipid syndrome may bind to activated platelets through beta 2GPI.
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PMID:Exposure of anionic phospholipids upon platelet activation permits binding of beta 2 glycoprotein I and through it that of IgG antiphospholipid antibodies. Studies in platelets from patients with antiphospholipid syndrome and normal subjects. 791 7

Renal artery infarction is a very rare complication in patients with systemic lupus erythematosus (SLE), even in patients with antiphospholipid syndrome which often causes thromboembolism: Renal infarctions have only been reported in 4 SLE patients with antiphospholipid antibodies (aPL). Here we report a case of SLE without aPL who accompanied by renal and cerebral infarctions. A 42-year old Japanese woman with 8 year history of SLE manifested by arthralgia, central nervous system symptoms, positive-antinuclear and anti-DNA antibodies was admitted to our hospital for the treatment of progressive lupus nephritis. Physical examinations revealed hypertension (130-160/80-110 mmHg) without pitting pretibial edema. Laboratory evaluations showed proteinuria (3.7 g/day), normal serum creatinine level (0.9 mg/dl), low serum albumin level (2.3 g/dl) and high cholesterol level (317 mg/dl). Old cerebral infarctions were recognized by magnetic resonance imaging. However, hematological and immunological studies revealed that this case has neither a prolonged activated partial thromboplastin time, lupus anticoagulant nor anticardiolipin antibodies. Prednisolone was increased from 30 mg/every other day to 30 mg/day, and oral azathioprine, 50 mg/day, was started for the treatment of lupus nephritis. On the 11th day, she suddenly complained severe abdominal pain, which gradually localized on the right side. Computed tomography of the kidney suggested right renal infarctions, and arteriography of right renal artery confirmed both an obstruction of the ventral branch and a narrowing of the dorsal branch of right renal artery. No intra-cardiac thrombus was demonstrated by echocardiography. Following to the treatment with fibrinolytic agent and anticoagulant, her symptoms have improved.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:[Renal and cerebral infarctions in a patient with systemic lupus erythematosus without antiphospholipid antibodies]. 823 16


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