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Query: UMLS:C0149871 (deep vein thrombosis)
 12,364 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Pulmonary embolism can produce severe cardiopulmonary dysfunction characterized by pulmonary artery hypertension, right ventricular failure, and hypoxemia. The search for the source of a pulmonary embolus, by exploration of the veins of the lower limbs and the inferior vena cava should be systematically carried out in all cases of pulmonary embolus which are not immediately life-threatening to the patient. The treatment of deep vein thrombosis associated with pulmonary embolism with thrombolytic agents has been proposed and utilized for approximately 20 years. Although superior results have been claimed with thrombolytic agents, the use of this type of treatment remains limited to massive or sub-massive pulmonary embolism. Fibrinolytic agents with high specificity for fibrin in the thrombi and little systemic activation of the fibrinolytic system have been developed and tested in preliminary clinical trials of patients with acute pulmonary embolism. The largest published experience available has been with recombinant tissue plasminogen activator (rtPA). The acylated streptokinase-plasminogen complex (APSAC) and pro-urokinase also gave promising results. All these agents were accompanied by unexpectedly high incidence of systemic activation of the fibrinolytic system and by hemorrhagic complications with frequencies similar to those that follows the use of first generation products (urokinase and streptokinase). Hence, their superior clinical efficacy must be clearly proven before they are substituted for a more widely available and less expensive drug, such as streptokinase.
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PMID:Pathogenesis and management of acute pulmonary embolism. 251 49

The plasma concentrations of tissue plasminogen activator (t-PA) antigen, cortisol, testosterone, dehydroepiandrosterone sulphate, FSH and LH were studied in 33 men undergoing major abdominal surgery. Significant positive correlation was found between the concentrations of t-PA antigen and cortisol, suggesting that the adrenal cortex has a role in the regulation of extrinsic fibrinolysis. These two variables, however, did not distinguish between patients with postoperative deep vein thrombosis (diagnosed by 125I-fibrinogen uptake test) and those without this complication. Such distinction was possible, however, with another steroid hormone of the adrenal cortex, dehydroepiandrosterone sulphate. At present, no explanation in terms of haemostatic mechanisms can be offered for this finding.
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PMID:Relationships between tissue plasminogen activator, steroid hormones and deep vein thrombosis. 293 51

Using affinity chromatography on lysine Sepharose 4B, a fast-acting tissue plasminogen activator inhibitor (t-PAI) was partially purified from t-PAI-rich plasma from patients with recurrent DVT. Its inhibition of tissue plasminogen activator (t-PA) was demonstrated in functional assays and its reaction with 125I-t-PA was analyzed by autoradiography following SDS-PAGE (sodium dodecyl sulfate polyacrylamide gel electrophoresis). When the t-PAI was mixed with an equimolar concentration of t-PA at 37 degrees C, the half-life of free one-chain and two-chain 125I-t-PA was 1.8 and 0.8 min, respectively. The rate of complex formation between 125I-t-PA and t-PAI was similar both in patient plasma, pregnancy plasma and platelet lysates made from platelet-rich normal, patient and pregnancy plasma. The molecular weights of the complexes between t-PA and the inhibitors in patient plasma and in the different platelet lysates were identical, while that of the inhibitor complex formed in pregnancy plasma was found slightly higher by SDS-PAGE indicating that the pregnancy plasma t-PAI differs from the fast-acting t-PAI found in plasma from thrombotic patients and in platelet lysates.
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PMID:Plasminogen activator inhibitors in plasma and platelets from patients with recurrent venous thrombosis and pregnant women. 308 15

Euglobulin lysis time (ELT), tissue plasminogen activator (tPA), and the fast-acting inhibitor of tPA, were measured pre-operatively in 128 patients who underwent elective major abdominal surgery. Deep venous thrombosis (DVT) was detected by 125I-labelled fibrinogen scan in 37 patients (29 per cent) after operation. Pre-operatively, there was diminished euglobulin lysis activity (332 +/- 197 versus 255 +/- 156 min, mean +/- s.d.; P less than 0.025), and tissue plasminogen activator activity (4.2 +/- 9.9 versus 7.7 +/- 14.3 milliunits/ml, mean +/- s.d.; P = 0.094) in patients who subsequently developed postoperative DVT compared with those who did not. There was no significant difference between the two groups in the level of inhibition of tissue plasminogen activator (160.6 +/- 75.4 per cent versus 152.5 +/- 77.5 per cent, mean +/- s.d.; n = 47). Stepwise logistic discriminant analysis of the data obtained preoperatively showed that tissue plasminogen activator, a more specific measure of fibrinolytic activity, was a weaker predictor of DVT than euglobulin lysis time. The results confirm other observations which indicate that lowered fibrinolytic activity is a risk factor for postoperative DVT. In addition, they suggest that this is not due entirely to low levels of activity of tissue plasminogen activator in plasma.
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PMID:Indicators of depressed fibrinolytic activity in pre-operative prediction of deep venous thrombosis. 310 52

The use of fibrinolytic agents to control the fibrinolytic enzyme system and lyse pathologic fibrin deposits or thrombus has now assumed a position with anticoagulants and vascular surgery in the physician's therapeutic armamentarium. The principal exogenous activators that are used clinically are streptokinase, urokinase, and tissue plasminogen activator. Acute arterial occlusions are more likely than chronic occlusions to respond to thrombolytic therapy, especially if treatment is instituted within a few hours of onset of symptoms and if the disease is due to embolic material rather than in situ thrombosis. Since the duration of drug infusion necessary to lyse arterial thrombus cannot be predicted, patients in whom tissue viability cannot be determined or in whom ischemia cannot be tolerated during the drug infusion interval are not candidates for intraarterial fibrinolytic drug infusion. In treating patients with venous occlusion, thrombolytic therapy is more effective against proximal clots than in calf thrombosis. No protective effect from pulmonary embolism has been noted in trials comparing heparin with streptokinase. Fifty percent of patients with an initial episode of deep venous thrombosis treated within 72 hours of onset will have complete resolution of thrombus with preservation of valve function.
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PMID:Application of thrombolytic therapy in vascular occlusive disease. A surgical view. 311 28

Alteration of the fibrinolytic system is considered to be important in the development of deep venous thrombosis (DVT). Using specific assays for tissue plasminogen activator (t-PA) activity, t-PA inhibitor (PAI) and t-PA antigen, we measured these activities in 16 women who developed DVT during their pregnancies. A group of 24 healthy females of comparable age was studied as controls. PAI was increased in 87% of these patients compared to the healthy controls. In some of these patients a defect in release of t-PA from vascular endothelium was found as well. The site at which blood was sampled for analysis appeared to be an important criterion in the ex vivo assessment of functional t-PA reserve and PAI levels, though relatively less so for the latter measurement. The unaffected lower limbs, relative to the unaffected upper limbs, showed an increase in PAI and a demonstrable decrease in t-PA release, both representing increased risk factors for rethrombosis. The affected lower limbs showed similar but more accentuated changes in these parameters.
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PMID:Altered fibrinolysis in DVT: influence of site of sampling. 314 91

This study consisted of 52 patients admitted for orthopedic surgery and 28 patients admitted for general surgery, who were treated with Sequential Compression Devices (SCD) and Thromboembolic Deterrent Stockings (TEDS) and monitored for the development of deep vein thrombosis (DVT). Coagulation and fibrinolytic profiles were carried out on these patients preoperatively, and on days one, three, and six postoperatively. All patients were followed by I-125-Fibrinogen scanning, Venous Doppler, and Impedance Plethysmography studies for clot detection. In the orthopedic surgery group, six (11.5%) developed DVT, and in the general surgery group, one (3.6%) developed DVT. No patients developed pulmonary embolism. The combined incidence of DVT was 8.8 per cent. A variety of parameters was measured in order to determine whether compression devices prevent a fibrinolytic shut-down commonly seen in the postsurgical patient. A combination of three assays was found to be significant in demonstrating a fibrinolytic response. These parameters were a post-surgical decrease in the plasminogen level, an increase in the level of free protease activity postoperatively, and an increase in the level of tissue plasminogen activator after surgery. 56.3 per cent of all patients treated with SCD and TEDS showed a fibrinolytic response on postoperative day one by a combination of all three of these parameters. In the group of patients that developed DVT none showed an increase in free protease activity, and five of seven showed no significant decrease in plasminogen and no increase in tissue plasminogen activator. Patients who developed thrombosis had measurable differences in their fibrinolytic system compared to those without postoperative thrombosis.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Relationship between postsurgical fibrinolytic parameters and deep vein thrombosis in surgical patients treated with compression devices. 327 80

Heparin (Lipo-Hepin, Liquaemin Sodium) and warfarin sodium (Coumadin, Panwarfin) are the classic anticoagulants in use for venous thromboembolic disease. They work by modifying the coagulation mechanism, heparin having an immediate effect and warfarin having a more delayed effect. The most common adverse effects of anticoagulation therapy are hemorrhagic complications. Thrombolytic therapy should be considered in all patients with massive pulmonary embolism with hypotension and in patients with deep venous thrombosis in the popliteal area or higher. Such therapy has been shown to help preserve the pulmonary microcirculation after pulmonary embolism and to decrease the incidence of the postthrombotic syndrome following deep venous thrombosis. If certain clinical guidelines are followed rigidly, the incidence of significant bleeding complications is low. Although the use of tissue plasminogen activator in venoocclusive disease has been limited to isolated cases, results have been very promising.
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PMID:Treatment of venous thromboembolic disease. A pragmatic approach to anticoagulation and thrombolysis. 370 54

Plasminogen, fibrinogen, antithrombin III, euglobulin lysis time, tissue plasminogen activator (t-PA) and fast-acting t-PA inhibitor were measured in 21 patients receiving either stanozolol (10 mg orally given for 14 days preoperatively) or subcutaneous heparin, during a continuing comparative trial in the prevention of postoperative deep vein thrombosis. Stanozolol treatment resulted in significant (p less than 0.01) increases between the 14th and 1st preoperative days in the plasma concentrations of plasminogen (3.4 to 4.9 Cu/ml) and antithrombin III (107% to 132%); t-PA levels did not increase significantly (6.0 to 16.0 mU/ml; p greater than 0.1). There were significant (p less than 0.02) falls in fast-acting t-PA inhibitor (132% to 75%) and fibrinogen (2.4 to 1.8 g/l). Surgery reversed the changes in fibrinolytic activity seen preoperatively in the stanozolol-treated patients, and similar changes were seen in the heparin-treated group. In this dosage, stanozolol does not appear to prevent the fibrinolytic shutdown which occurs after elective major surgery.
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PMID:Effects of oral stanozolol used in the prevention of postoperative deep vein thrombosis on fibrinolytic activity. 387 18

The aim of these studies was to investigate different regimens of thrombolytic therapy and oral anticoagulation, and to evaluate the effects of streptokinase (SK), heparin and warfarin in the treatment of deep vein thrombosis (DVT). Low-dose SK, although controlled according to the fibrinogen levels, did not provide improved thrombolysis compared to conventional high-dose SK, and more postthrombotic changes were registered after an average of 3 years. Furthermore, serious hemorrhagic side-effects occurred, which makes this regimen inexpedient. Various regimens of local venous infusion of SK were tried, and with a dose of 4,000 IU/h for 72 h in combination with heparin a thrombolytic effect was achieved, albeit not greater than usually observed with conventional SK. Systemic hypofibrinogenemia and hemorrhage were not avoided. A hitherto not described side-effect with bullous dermatitis was reported. Venographic severity of calf vein thrombosis displayed a statistically significant correlation to long-term hemodynamic changes, as assessed with foot volumetry, after an average of 5 years. This correlation was stronger for the size of the thrombus after initial treatment than for the size at diagnosis. Thus it seems important to treat calf vein thrombosis with heparin in order to limit the extent of the thrombus, thereby reducing long-term sequelae. During heparin treatment, an average reduction of the thrombi of 17% was observed. This reduction was significantly correlated to a short duration of symptoms but not to parameters of heparin therapy or fibrinolytic components. However, patients with substantial thrombolysis had high plasmin-alpha 2-antiplasmin (PAP) levels, and those with high tissue plasminogen activator (t-PA) inhibitor levels and remarkably also those with high t-PA antigen levels had no lysis. The concentration of t-PA antigen showed a significant increase during heparin infusion, whereas that of PAP and t-PA inhibitor was not influenced. By applying more intensive initial oral anticoagulation, stable therapeutic prothrombin time (PT)-levels were achieved one day earlier and the duration of heparin infusion could be equally reduced compared to the conventional regimen (4.4-5 days vs 5.4-6 days). The activity of coagulation factors II, VII, IX and X had dropped to the same level with both regimens the day heparin was discontinued, observed. The effectiveness of oral anticoagulation after DVT was studied in 596 patients treated for a total of 4450 months.(ABSTRACT TRUNCATED AT 400 WORDS)
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PMID:Studies on the medical treatment of deep vein thrombosis. 391 82


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