Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0149871 (deep vein thrombosis)
 12,364 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Dextran is known to increase the plasminogen activation rate in vitro and to decrease the alpha2-antiplasmin activity. We decided to explore the effect of dextran on plasma tissue plasminogen activator (t-PA) and plasminogen activator inhibitor-1 (PAI-1) during surgical trauma. Thirty-one patients undergoing elective surgery were given 500 ml of 6% dextran 70. Another nine patients serving as controls were given 500 ml of a glucose-electrolyte solution. The activities of t-PA and PAI-1 during surgery were determined, as was the concentration of t-PA antigen. PAI-1 activity was decreased by 19% after infusion of 250 ml of dextran. After 500 ml, the activity was reduced by 22% (both P < 0.05). The activity of t-PA was increased by 43% and 29% (both P < 0.05) and the antigenic amount of t-PA was increased by 18% and 15% (both P < 0.05) after infusion of 250 ml and 500 ml of dextran, respectively. No changes in these variables were observed in the control patients. It is concluded that infusion of dextran promotes fibrinolysis by enhancing plasminogen activation in patients subjected to trauma. Since elevated levels of PAI-1 prior to surgery are known to predispose to deep vein thrombosis, which may form already during the operation, the effect of dextran on PAI-1 described here may explain its clot preventing properties.
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PMID:Effect of dextran on plasma tissue plasminogen activator (t-PA) and plasminogen activator inhibitor-1 (PAI-1) during surgery. 754 Jul 88

We introduce a new fibrin plate assay performed in microtiter plates. By means of spectroscopic studies we optimized the structure of the fibrin gel and then used the optimized fibrin gel to determine plasminogen activator activity. Plasminogen activator solutions were applied on top of the fibrin gel, and the absorbance of the gel was recorded at 405 nm. After incubation for 17 h at 25 degrees C, the absorbance was measured again. The difference in absorbance was proportional to the concentration of plasminogen activator, such that the dose-response curves were linear when the difference in absorbance was plotted as a function of the logarithmic concentration of plasminogen activator. We assayed both tissue-type and urokinase-type plasminogen activator activity. The intraassay CV was < 4.7% (n = 20); the interassay CV was < 3.1% (n = 15). Using the optimized procedure, we modified the assay for determination of plasma-coagulum lysis time in human plasma. We established a reference interval for lysis time in apparently healthy subjects of 75 to 201 ks. Patients with deep vein thrombosis showed significantly (P = 0.013) higher values.
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PMID:Plasminogen activator activity and plasma-coagulum lysis measured by use of optimized fibrin gel structure preformed in microtiter plates. 754 22

Patients with a recent (less than 10 days) proximal deep vein thrombosis of the leg or pelvis are candidates for thrombolysis as the major benefit over heparin seems to be the prevention of the postphlebitic limb, an aim which is still not proven in a satisfactory manner. Nonocclusive thrombi appear to lyse more readily than occlusive thrombi. For this indication the optimal dose regimens for the three thrombolytic drugs (streptokinase, urokinase, alteplase) are not established. Acute massive pulmonary embolism with hypotension or shock should be treated with thrombolytic drugs and, pending the outcome in the first hour, be considered for pulmonary embolectomy. Major acute pulmonary embolism with haemodynamic instability responds well to thrombolysis. Whether thrombolysis is superior to heparin in subacute intermediate pulmonary embolism has not been proven unequivocally in terms of mortality or clinically important endpoints. Systemic administration of thrombolytic drugs for peripheral arterial occlusion has been abandoned for catheter-directed and intraoperative intra-arterial repeated bolus or short-term infusions. The efficacy and safety of intravenous thrombolytic treatment following a major ischaemic stroke is presently being tested in large scale trials; its use must be restricted to experimental protocols.
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PMID:Thrombolytic therapy of non-cardiac disorders. 754 71

Ten days after surgical treatment of a gastric perforation a 70-year-old woman developed progressive dyspnoea and hypertension without any signs of deep vein thrombosis. Emergency echocardiography revealed acute cor pulmonale with a dilated right atrium and ventricle, as well as paradoxical ventricular septal motion. In addition it demonstrated an elongated, extremely mobile thrombus stuck in a patent foramen ovale with most of it floating in the right atrium, the remainder in the left atrium. Within 2 hours of the ultrasound examination she went into fulminant pulmonary embolism with circulatory arrest and paradoxical embolization from the atria to the brain, after which the intraatrial thrombus was no longer detectable. She was successfully resuscitated and thrombolysis was immediately started with tissue-plasminogen activator (100 mg over 90 min), with ensuing stabilization of the circulation. The patient was gradually weaned off the ventilator over the following few days, but she died 10 days after the resuscitation from the severe cerebral damage.
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PMID:[Transient thrombus in patent foramen ovale with pulmonary and paradoxical embolization]. 824 45

Fibrinolysis of 19 patients who developed CVI after deep vein thrombosis was examined. Mean age of patients at the first thrombosis was 31.8 years. For testing fibrinolysis fibrinogen, plasminogen, AP, ECLT, with venous occlusion were determined. In 10 patients t-PA and PAI-1 activities were also measured and plethysmography was carried out. For screening blood coagulation abnormalities of TCT count, PT, APTT, TT, AT III, protein C were tested. The common abnormality was the decreased fibrinolysis. Patients had been on coumarin for 6.14 years before entering the study. Under coumarin treatment 6 patients had relapsed DVT, 4 had crural ulcer and CVI deteriorated in 8 patients. Therefore we added fibrinolysis increasing PPS to coumarin. PPS dose was individually determined by PPS loading test (150-500 mg). Mean observation time with the combined treatment was 2.92 years. Clinical check up and fibrinolysis test were carried out every 6 months. Clinical improvement occurred in 13 patients, (decrease of swelling, pain etc). Two out of 4 patients with stasis ulcer experienced complete healing; in 1 the ulcer territory diminished in size. Maximum venous outflow improved in 7 patients, 3 patients were non-responders. We observed an increase of fibrinolysis in 10 patients. Venous occlusion enhanced the fibrinolysis increasing effect of PPS. The activity reached its maximum by the first control. The fibrinolysis increase and the clinical improvement do not always run parallel, therefore other effects of PPS as the reason for being beneficial in CVI must be considered (antiinflammatory, ect.). Combination of coumarin and PPS seems to be an effective therapy in CVI with decreased fibrinolysis.
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PMID:[Management of chronic venous insufficiency with the combination of coumarin (Syncoumar) and oral pentosan polysulfate (PPS, SP 54) (preliminary report)]. 767 12

Management of thromboembolic disease involves administration of anticoagulants, thrombolytics or antiplatelet agents to lyse or prevent thrombus extension. Despite widespread use and decades of experience with some of these agents, much is unknown about the effects of dose and plasma concentration on patient response. Unfractionated heparin (UFH) improves outcome in many thromboembolic disorders when administered to a target activated partial thromboplastin time (aPTT) or plasma heparin concentration. UFH exhibits dose-dependency both with absorption from subcutaneous sites and elimination. Doses based on bodyweight or estimated blood volume attain therapeutic aPTTs faster than fixed or standard doses. Low molecular weight heparins (LMWHs) were developed to increase the anti-factor Xa:anti-factor IIa activities. Several different LMWHs are as effective as UFH in treating deep venous thrombosis. Evidence fails to support a relationship between anti-factor Xa activity and either thrombosis evolution or bleeding. No comparisons have been made between bodyweight-based and anti-factor Xa activity-based doses. The dose of orally administered warfarin is adjusted to achieve a target International Normalised Ratio (INR). Maintenance doses are estimated on the basis of the patient's INR during the first 3 days of therapy: the dose required to achieve an optimal INR decreases with age > 50 years. The thrombolytic agents are administered in standard doses to achieve rapid thrombolysis with minimal alteration in systemic haemostasis. Accelerated intravenous alteplase may result in the highest rate of coronary artery reperfusion. Nevertheless, standard doses of streptokinase, anisoylated plasminogen streptokinase complex and alteplase result in similar 1-month mortality rates. The minimal advantage seen with alteplase is offset by higher rates of stroke. Future trials will focus on administration strategies achieving rapid thrombolysis, while minimising the risk of serious bleeding. With the antiplatelet agents, unpredictability in the pharmacokinetic parameters of different products has confounded interpretation of published reports. Optimal aspirin (acetylsalicylic acid) administration would include administration of an initial dose of 160 to 325mg after an acute vascular event, followed by maintenance dosages of approximately 75 mg/day for prophylaxis or treatment. Ticlopidine does not exhibit a relationship between either plasma concentration or dose and adverse effects, while pharmacodynamic effects may be dose-, but not plasma concentration-, dependent. The correlation between the concentration of dipyridamole and some of its antiplatelet effects may be the strongest amongst all the antiplatelet agents. However, unfortunately all clinical trials used standard doses and the current consensus is that dipyridamole alone is not an effective antiplatelet agent.
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PMID:Pharmacokinetic optimisation of the treatment of embolic disorders. 771 62

During the last 10 years anticoagulant (AC) therapy and thrombolytic treatment of venous thromboembolism (VT) have been evaluated in randomized studies. Adjusted subcutaneous (s.c.) heparin and low molecular weight heparin (LMWH) are found at least as effective as intravenous (i.v.) infusion of heparin in deep venous thrombosis (DVT) without an increased bleeding risk. In pulmonary embolism (PE) randomized trials assessing the efficacy of s.c. heparin and LMWH are missing. Oral AC-treatment can be initiated from the first or second day in VT. The recommended duration is three months for medical patients, and 4 weeks seem appropriate for surgical patients that are completely mobilized and without persisting predisposing factors. Long-term efficacy of thrombolytic treatment of DVT has only been assessed in small trials showing a trend towards reduced risk of developing chronic venous insufficiency. Short-term thrombolytic treatment of DVT is evaluated in ongoing trials. In the treatment of PE short-term thrombolysis with either t-PA or urokinase is found to be as effective as long-term thrombolytic treatment with a reduced bleeding risk. Thrombolytic therapy rapidly reduces embolic mass and stabilizes haemodynamics, but mortality and long-term efficacy of thrombolysis and AC-treatment versus AC-treatment alone in PE are being assessed in ongoing studies.
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PMID:[Anticoagulant and thrombolytic therapy in deep venous thrombosis and pulmonary embolism]. 778 97

Massive deep venous thrombosis with marked venous outflow obstruction can result in limb loss or end-organ injury. Systemically administered drugs may not reach thrombi in therapeutic concentrations and surgical and thrombolytic strategies carry a small but real risk of pulmonary embolus--similar to the risks with anticoagulation alone. We therefore developed a strategy in which catheter-directed thrombolysis was used to deliver high concentrations of a plasminogen activator directly to the thrombus combined with placement of a downstream Greenfield filter to protect patients from pulmonary embolus. From 1984 to 1993 six patients were treated with this regimen. All had severe symptoms of less than 4 days' duration. On radiologic evaluation four patients had large iliofemoral and/or inferior vena cava thrombosis, one had subclavian/innominate vein thrombosis, and one had transplant renal vein/iliofemoral/inferior vena cava thrombosis. A Greenfield filter was first placed downstream prior to imbedding an infusion catheter in the greatest mass of thrombus for subsequent infusion of urokinase (n = 4) or streptokinase (n = 2). In four patients the catheter traversed the Greenfield filter. All patients were given bolus lytic therapy followed by maintenance infusions ranging in duration from 24 hours to 12 days. Five patients remained on heparin simultaneously. Clot lysis was achieved in all patients with hemodynamic, symptomatic, and arteriographic improvement. There were no deaths, pulmonary emboli, or complications of filter placement. One patient had minor bleeding at the puncture site and another had catheter-related infection.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Catheter-directed thrombolysis following vena cava filtration for severe deep venous thrombosis. 786 98

The first generation high-dose ( 80 mcg estrogen) oral contraceptives (OCs) were associated with an increased risk of deep venous thrombosis (DVT). So manufacturers removed the high-dose OCs and first replaced them with OCs with 50 mcg estrogen, resulting in a lower incidence of thromboembolic events (40 vs. 20/100,000 users). When they introduced an even lower dose OC (30 mcg estrogen), the incidence fell further (about 8/100,000 users). Yet, women using the lowest-dose OCs still have DVT more often than do control women. Life-style, age, and smoking may be confounding factors, however. It is not clear whether loss of endogenous ovarian steroid production or the effects of the orally administered contraceptive steroids cause significant changes in hemostatic factors (antithrombin III, protein S, protein C, plasminogen, tissue-type plasminogen activator, plasminogen activator inhibitor 1, histidine-rich glycoprotein, and VII, VIII, X, XII coagulation factors) during OC use. These changes tend to be within normal ranges. There is some doubt that these changes have any clinical significance. In nonsmokers, increased activity of anticoagulant factors and fibrinolytic factors counteract the effects on coagulation factors. Progestin-only OCs appear to affect hemostasis but have not increased the risk of thrombosis. There are considerable differences between people in pharmacokinetics and pharmacodynamics of contraceptive steroids. These differences may account for the increased risk of thromboembolic events in some people. Further research should identify methods of individualizing the dose of contraceptive steroids for a single patient. It should also explore the close interrelationship between hemostasis and lipid metabolism, carbohydrate metabolism, and hypertension in the development of cardiovascular disease in OC users. Providers should discourage women with a past history of DVT from using hormonal contraception.
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PMID:Coagulation and anticoagulation effects of contraceptive steroids. 817 1

Thrombolysis in deep venous thrombosis is indicated in documented thrombosis of the legs, because, in most cases, it is due to no or minimal collateral flow with bad prognosis. Thrombolysis should not be used regularly in isolated thrombosis of the veins of the lower legs and in subclavian vein thrombosis. The aims in therapy of deep venous thrombosis are reduction of possible complications such as fatal pulmonary embolism, avoidance of progression and recurrence, respectively, and avoidance of a postthrombotic syndrome. In contrast to heparinization, thrombolysis has the advantage of high recanalization rates, but the disadvantage of higher incidence of hemorrhage. With clinically proven dosage regimens of streptokinase and urokinase in our experience, complete recanalization rates are in the range of 30% of primary occluded vessels. According to pivotal and dose-finding studies, the results with tissue plasminogen activator (t-PA) are within the same range. In a different approach, the thrombolytic substances are delivered in a loco-regional type via a vein of the foot. There is some evidence from pivotal clinical trials that the same recanalization rates are obtainable as with streptokinase in ultrahigh dosage. Considering the individual importance and also the epidemiologic and economic value of deep venous thrombosis, there is a need for prospective, randomized trials. Results of clinical studies currently under way will hopefully show the benefit of such new therapeutic strategies.
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PMID:[Deep venous thromboses--established treatment procedures and new trends]. 832 9


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