Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:3.4.21.73 (urokinase-type plasminogen activator)
 10,685 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Patients with iliofemoral deep venous thrombosis suffer the most severe postthrombotic morbidity. Techniques that effectively remove thrombus from the venous system eliminate venous obstruction and potentially preserve valvular function. This will likely reduce or avoid the postthrombotic syndrome and improve long-term quality of life. To evaluate whether catheter-directed thrombolysis is associated with improved quality of life compared with anticoagulation alone and whether outcome in the thrombolysis group is related to lytic success, 98 patients with iliofemoral deep venous thrombosis who were treated at least 6 months earlier were identified and queried with a validated health-related quality-of-life questionnaire. Sixty-eight patients were identified through the Venous Registry (a national, multicenter venous registry) and were treated with catheter-directed thrombolysis with urokinase, and 30 patients were identified by means of medical record review and were treated with anticoagulation alone. All patients were candidates for thrombolysis; however, the treatment decision was made according to physician preference. The two treatment groups did not differ significantly in average time between the reference hospitalization and first contact. No difference was found in physical functioning and well-being between the groups before the development of deep venous thrombosis. Following treatment, patients receiving catheter-directed thrombolysis reported better overall physical functioning, less stigma, less health distress, and fewer postthrombotic symptoms compared to those patients treated with anticoagulation alone. Within the thrombolysis group, successful lysis correlated with health-related quality of life. Catheter-directed thrombolysis for the management of patients with iliofemoral deep venous thrombosis significantly improves health-related quality of life compared to similar patients treated with anticoagulation alone. Improved quality of life is related to successful thrombolysis. These data offer a compelling argument for a prospective randomized study.
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PMID:Quality-of-life improvement using thrombolytic therapy for iliofemoral deep venous thrombosis. 1255 44

We performed this study to evaluate the efficacy of catheter-directed thrombolysis with urokinase in treating acute symptomatic iliofemoral deep venous thrombosis associated with protein C and/or S deficiency. A total of 42 consecutive patients with deep venous thrombosis were seen between September 2000 and August 2002. Of these, catheter-directed thrombolysis via the popliteal vein was performed in 5 patients (11.9%) with acute iliofemoral deep venous thrombosis associated with protein C and/or S deficiency. Average duration of symptoms was 4.2 days (range, 1-7 days). The average urokinase dose was 2.7 million IU (range, 0.6 million to 7.0 million IU) infused over an average of 33.1 h (range, 16-67 h). Lysis was complete in all five treated cases. Two cases had underlying iliac venous stenoses (>50%) that were treated with angioplasty and stent placement. In one patient in whom recanalization of a right iliac vein occlusion was successful, thrombosis occurred in the treated vein within 3 weeks of intervention despite full anticoagulation therapy, and further intervention was required. There were no complications or clinically detectable pulmonary emboli. The technical and clinical success rates were 100%. This initial experience suggests that catheter-directed thrombolysis for treatment of acute symptomatic iliofemoral deep venous thrombosis associated with protein C and/or S deficiency is safe and effective.
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PMID:Deep venous thrombosis associated with protein C and/or S deficiency: management with catheter-directed thrombolysis. 1281 23

Arterial and venous thromboembolic events, including myocardial infarction, ischemic stroke, peripheral arterial thrombosis, deep venous thrombosis, and pulmonary embolism are common potentially life-, organ-, and limb-threatening vascular diseases. Anticoagulant therapy is recommended in these settings to prevent further thrombosis pending gradual clearance of the thrombotic occlusion by the endogenous fibrinolytic system. Recognition of the importance of the fibrinolytic system in thrombus resolution has resulted in the development of pharmacologic fibrinolytic (thrombolytic) agents to facilitate rapid restoration of vascular patency. Several plasminogen activator (PA) thrombolytic agents with different pharmacokinetic and pharmacodynamic properties have been developed to treat thrombotic disease. Newer PAs have been developed as "fibrin-specific", bolus-administration drugs to primarily treat acute coronary syndromes. Continuous infusions of these fibrin-specific PAs have become popular for the lysis relatively larger peripheral vascular thromboses. Loss infusion of newer tissue-type plasminogen activator-based PAs may result in an increased risk of bleeding, including intracranial hemorrhage. Currently available data fail to provide compelling evidence that newer PAs offer significantly greater efficacy and safety than well-established agents like urokinase when used to treat peripheral vascular thrombosis.
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PMID:Pharmacologic and clinical characteristics of thrombolytic agents. 1511 13

The intrathrombus delivery of thrombolytic agent to patients with deep vein thrombosis extending above the groin was introduced in the early 1990s as an alternative to systemic thrombolysis. The technique requires proper positioning of an indwelling catheter with its tip into the thrombus. Up to now urokinase as well as alteplase have been used in different dosage schemes. Repeated injection of contrast fluid monitors progress of treatment. Rapid lysis with restoration of patency is achieved in roughly three of four patients treated, usually with prompt clinical improvement. Underlying stenotic lesions are frequently relieved by insertion of metallic stents. Data on long term patency are still scarce, and no comparative trials with conventional anticoagulation are available. Bleeding is the most feared complication, and a few serious bleeding incidents have been reported. Local thrombolysis appears an interesting but labor-intensive approach in expert hands, but a definite place in management of venous thrombosis remains to be established.
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PMID:Endovascular local thrombolytic therapy of ileofemoral and inferior caval vein thrombosis. 1519 22

Plasma levels of granulocyte-derived elastase (GE-XDP), D-dimer and soluble fibrin (SF) were examined in 53 patients with deep vein thrombosis (DVT) and in 100 healthy volunteers. The mean plasma level of D-dimer was 0.92+/-0.81 microg/ml (+/-S.D.) in healthy volunteers and the mean+2 S.D. value (cutoff value for DVT) was 2.53 microg/ml, which was higher than that used in Europe and North America. Plasma levels of GE-XDP, D-dimer and SF were significantly higher in patients with DVT than in healthy volunteers, and diminished after 1 week of treatment with heparin, urokinase or tissue type plasminogen activator, though were still higher than those of the control subjects. The sensitivity of GE-XDP, D-dimer and SF for DVT was 81.1%, 75.5% and 79.2%, respectively. GE-XDP levels correlated with those of D-dimer and SF. Our results indicate that GE-XDP is a potentially useful marker for the diagnosis of DVT, suggesting that granulocytes are activated in patients with DVT. In our system, the cutoff value of D-dimer for the diagnosis of DVT is higher than in western countries, probably due to the use of different analytical assays.
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PMID:Elevated plasma levels of fibrin degradation products by granulocyte-derived elastase in patients with deep vein thrombosis. 1556 53

Thrombin inhibitors are potentially useful in medicine for their anticoagulant and antithrombotic effects. We synthesized and evaluated diverse heterocycle-activated ketones based on the d-Phe-Pro-Arg, and related thrombin active-site recognition motifs, as candidate inhibitors. The peptide-based alpha-ketoheterocycles were typically prepared by either an imidate or a Weinreb amide route (Schemes 1 and 2), the latter of which proved to be more general. Test compounds were generally assayed for inhibition of human alpha-thrombin and bovine trypsin. From a structure-based design standpoint, the heterocycle allows one to explore and adjust interactions within the S1' subsite of thrombin. The preferred alpha-ketoheterocycle is a pi-rich 2-substituted azole with at least two heteroatoms proximal to the carbon bearing the keto group, and a preferred thrombin inhibitor is 2-ketobenzothiazole 3, with a potent K(i) value of 0.2 nM and ca. 15-fold selectivity over trypsin. 2-Ketobenzothiazole 13 exhibited exceedingly potent thrombin inhibition (K(i) = 0.000 65 nM; slow tight binding). Several alpha-ketoheterocycles had thrombin K(i) values in the range 0.1-400 nM. The "Arg" unit in the alpha-ketoheterocycles can be sensitive to stereomutation under mildy basic conditions. For example, 2-ketothiazoles 4 and 59 readily epimerize at pH 7.4, although they are fairly stable stereochemically at pH 3-4; thus, suitable conditions had to be selected for the enzymatic assays. Lead d-Phe-Pro-Arg 2-benzothiazoles 3, 4, and 68 displayed good selectivity for thrombin over other key coagulation enzymes (e.g., factor Xa, plasmin, protein Ca, uPA, tPA, and streptokinase); however, their selectivity for thrombin over trypsin was modest (<25-fold). Compounds 3, 4, and 68 exhibited potent in vitro antithrombotic activity as measured by inhibition of gel-filtered platelet aggregation induced by alpha-thrombin (IC(50) = 30-40 nM). They also proved to be potent anticoagulant/antithrombotic agents in vivo on intravenous administration, as determined in the canine arteriovenous shunt (ED(50) = 0.45-0.65 mg/kg) and the rabbit deep vein thrombosis (ED(50) = 0.1-0.4 mg/kg) models. Intravenous administration of 3, and several analogues, to guinea pigs caused hypotension and electrocardiogram abnormalities. Such cardiovascular side effects were also observed with some nonguanidine inhibitors and inhibitors having recognition motifs other than d-Phe-Pro-Arg. 2-Benzothiazolecarboxylates 4 and 68 exhibited significantly diminished cardiovascular side effects, and benzothiazolecarboxylic acid 4 had the best profile with respect to therapeutic index. The X-ray crystal structures of the ternary complexes 3-thrombin-hirugen and 4-thrombin-hirugen depict novel interactions in the S(1)' region, with the benzothiazole ring forming a hydrogen bond with His-57 and an aromatic stacking interaction with Trp-60D of thrombin's insertion loop. The benzothiazole ring of 3 displaces the Lys-60F side chain into a U-shaped gauche conformation, whereas the benzothiazole carboxylate of 4 forms a salt bridge with the side chain of Lys-60F such that it adopts an extended anti conformation. Since 3 has a 10-fold greater affinity for thrombin than does 4, any increase in binding energy resulting from this salt bridge is apparently offset by perturbations across the enzyme (viz. Figure 4). The increased affinity and selectivity of 2-ketobenzothiazole inhibitors, such as 3, may be primarily due to the aromatic stacking interaction with Trp-60D. However, energy contour calculations with the computer program GRID also indicate a favorable interaction between the benzothiazole sulfur atom and a hydrophobic patch on the surface of thrombin.
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PMID:In-depth study of tripeptide-based alpha-ketoheterocycles as inhibitors of thrombin. Effective utilization of the S1' subsite and its implications to structure-based drug design. 1577 42

Thrombotic occlusive diseases are manifested in several disorders that have significant morbidity and mortality, including acute myocardial infarction, pulmonary embolism, deep venous thrombosis, and cerebrovascular accidents. This review summarizes the recently published literature covering thrombolytic therapies in these diseases, with particular attention to comparisons between the fibrin-specific tissue plasminogen activators (alteplase, reteplase, and tenecteplase) and the nonfibrin-specific activators (streptokinase or urokinase plasminogen activator). These agents act to convert plasminogen to plasmin, which in turn cleaves fibrin as part of the lysis process. Fibrin-specific activators were anticipated to be more efficacious and safer than nonspecific agents in thrombolytic occlusive diseases because of their pathophysiologically restricted mechanism of action. However, the fibrin-specific activators also lyse physiological hemostatic plugs, which can result in costly adverse events. Efficacy of fibrin-specific tissue plasminogen activators has been shown to be generally equivalent, with similar mortality rates compared with nonspecific agents; however, fibrin-specific agents may be associated with an increased incidence of intracerebral hemorrhage and with increased costs. Therefore, it appears that given equivalent efficacy, nonfibrin-specific activators, such as streptokinase or urokinase, may be a safer choice in many thrombotic situations.
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PMID:Thrombolytic therapies: the current state of affairs. 1582 70

This study was carried out to study the safety and efficacy of a fixed dosage of sulodexide compared to adjusted dosages (INR) of acenocoumarol as secondary prophylaxis in patients with deep vein thrombosis (DVT) in lower limbs. An economic evaluation based on the criteria of use in normal clinical practice was also performed. One hundred and fifty patients of both sexes were included, all over 18 years of age and diagnosed with proximal DVT of the lower limbs by color echo-Doppler, and with clinical evolution of less than 1 month. The patients were initially treated with low-molecular-weight heparin (LMWH) and urokinase in accordance with the established protocol. They were then randomized to continue treatment with acenocoumarol and INR adjustments every 30 days, or with sulodexide. Treatment was extended for 3 months with monthly follow-up visits and a final visit at 3 months posttreatment. No differences between the groups were detected concerning demographic or basal characteristics in clinical evolution or adverse reactions. In the group treated with sulodexide, no major/minor hemorrhagic complications were detected. On the other hand, in the acenocoumarol group, 1 major hemorrhage and 9 minor hemorrhages were produced (13.3%), reaching statistical difference in relation to the sulodexide group (p = 0.014; CI from 95% of 4.7% to 19.4%). Regarding the economic impact, treatment costs with sulodexide are much less than those with acenocoumarol, the data confirmed by the sensitivity analyses performed. The results prove the efficacy, safety, and efficiency of sulodexide as a secondary prophylaxis in thromboembolic disease, avoiding hemorrhagic risks and the monitoring of patients, and providing significant savings to the health system.
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PMID:A study on the safety, efficacy, and efficiency of sulodexide compared with acenocoumarol in secondary prophylaxis in patients with deep venous thrombosis. 1644 57

Early deep venous thrombosis (DVT) resolution is associated with neutrophil (PMN) influx. This study examined the role of PMNs in thrombus neovascularization and vein wall injury after DVT. A rat model of DVT by inferior vena cava (IVC) ligation was performed with control serum or rabbit anti-rat PMN serum administered perioperatively with sacrifice at 2 and 7 days. At 2 days, neutropenic rats had 1.6-fold larger thrombi (P = .04) and 1.4-fold higher femoral venous pressures by water manometry (P = .008) but no difference in thrombus neovascularization was observed. By 7 days, DVT sizes were similar, but vein wall injury persisted in the neutropenic rats with a 2.0-fold increase in vein wall stiffness by microtensiometry (P < .05), as well as a 1.2-fold increased thickness (P = .04). Collagen and profibrotic growth factors were significantly increased in neutropenic IVC at 7 days (all P < .05). Vein wall and intrathrombus uPA byWestern immunoblotting, and intrathrombus MMP-9 gelatinase activity were significantly less in neutropenic rats than controls (P < .001). Conversely, MMP-2 was significantly elevated in neutropenic IVC at 2 days after DVT. However, neutropenia induced 24 hours after DVT formation resulted in no significant increase in vein wall stiffness or collagen levels at 7 days, despite 1.4-fold larger thrombi (P < .05). These data suggest a critical early role for PMN in post DVT vein wall remodeling.
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PMID:Neutrophils modulate post-thrombotic vein wall remodeling but not thrombus neovascularization. 1649 89

Prior investigations have shown that low molecular weight heparin (LMWH) possesses anti-inflammatory properties in addition to its anticoagulant effects. The physiology of this anti-inflammatory mechanism is poorly understood. Experiments were performed to assess the in vivo anti-inflammatory effects of LMWH in a rat model of deep vein thrombosis (DVT). Sprague-Dawley rats were divided into three groups and underwent laparotomy and inferior vena cava (IVC) ligation directly below the renal veins to induce thrombosis. Twenty-four hours later, intraluminal clot was confirmed at repeat laparotomy using an electromagnetic flowmeter and visual inspection. An intravenous infusion of LMWH or urokinase or no infusion (control) was then performed. Subcutaneous LMWH was given postoperatively to the heparin group. Twenty-four hours after the second operation, the animals were killed, the IVC harvested, the cells from the IVC purified, and cytokine measurements done. The LMWH group showed an overall statistically significant decrease in tumor necrosis factor-alpha (TNF-alpha) levels compared to both the control and urokinase groups by analysis of variance (918 pg/mL vs. 1,345 and 1,623, respectively; P = 0.001). To ensure accuracy, individual pairwise comparisons were performed, which also showed statistically significant TNF-alpha suppression by LMWH compared to control (P = 0.015) and urokinase (P = 0.0009). Treatment of DVT with LMWH causes suppression of TNF-alpha expression. This may, in part, explain its anti-inflammatory effects.
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PMID:Low molecular weight heparin suppresses tumor necrosis factor expression from deep vein thrombosis. 1734 36


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