Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UMLS:C0034065 (pulmonary embolism)
 14,979 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The murine monoclonal antiplatelet antibodies MA-TSPI-1 (directed against human thrombospondin) and MA-PMI-2, MA-PMI-1, and MA-LIBS-1 (directed against ligand-induced binding sites [LIBS] on human platelet glycoprotein IIb/IIIa) were conjugated with recombinant single-chain urokinase-type plasminogen activator (rscu-PA) using the cross-linking reagent N-succinimidyl 3-(2-pyridyldithio)propionate (SPDP). The conjugates (rscu-PA/MA-TSPI-1, rscu-PA/MA-PMI-2, rscu-PA/MA-PMI-1, and rscu-PA/MA-LIBS-1), purified by immunoadsorption and gel filtration, were obtained with recoveries of 34% to 45%, with an average stoichiometry of 1.6 to 1.8 IgG molecules per rscu-PA molecule, and with unaltered specific activities and affinities. Preincubation of human platelet-rich plasma with rscu-PA/MA-PMI-2, rscu-PA/MA-PMI-1, or unconjugated rscu-PA resulted in partial inhibition of ADP-induced aggregation; 25% inhibition was obtained with 63 micrograms/mL rscu-PA and with 6 micrograms u-PA/mL rscu-PA/MA-PMI-2 or 1.2 micrograms u-PA/mL rscu-PA/MA-PMI-1. In an in vitro system composed of a 125I-fibrin-labeled platelet-rich human plasma clot immersed in normal human plasma, the conjugates had threefold to greater than 15-fold less fibrinolytic potency than unconjugated rscu-PA. The thrombolytic potency of rscu-PA/MA-PMI-1 and rscu-PA/MA-LIBS-1 was compared with that of rscu-PA and that of a control conjugate rscu-PA/MA-1C8 in a pulmonary embolism model in the hamster, using clots prepared from platelet-poor or platelet-rich human plasma. Lysis was measured 30 minutes after the end of a 60-minute intravenous infusion of the thrombolytic agents. rscu-PA, rscu-PA/MA-PMI-1, rscu-PA/MA-LIBS-1, as well as rscu-PA/MA-1C8 had comparable thrombolytic potencies (percent lysis per dose administered) towards platelet-poor human plasma clots. In contrast, the thrombolytic potency of rscu-PA/MA-PMI-1 and of rscu-PA/MA-LIBS-1 towards platelet-rich clots was 2.3- to 3-fold higher than that of rscu-PA (P less than .005) and fivefold to sevenfold higher than that of the control conjugate (P less than .01).
 ...
PMID:Effect of chemical conjugation of recombinant single-chain urokinase-type plasminogen activator with monoclonal antiplatelet antibodies on platelet aggregation and on plasma clot lysis in vitro and in vivo. 183 Oct 57

P280, a synthetic peptide composed of 26 aminoacids, has high affinity (Kd = 100 nM) and specificity for the glycoprotein IIb/IIIa (GPIIb/IIIa) receptor expressed on activated platelets. In this study we investigated the potential usefulness of imaging deep vein thrombosis (DVT) and pulmonary embolism (PE) in humans with 99mTc-P280. In 15 patients (9 men and 6 women; mean age +/- s.d.: 49.2 +/- 14.1) with known DVT and/or PE, serial images were acquired within 24 hours of the injection of approximately 200 micrograms of P280 radiolabelled with 10-23 mCi of 99mTc. P280 was labelled with the ligand exchange method using 99mTc-glucoheptonate. Rapid blood clearance (< or = 5% ID was still circulating in 1 hour) enabled identification of thrombi as early as 60 minutes after the injection, with significant thrombi-to-background ratios (range: 2-4) in 11/15 patients (73%), in 7/9 with DVT, in 2/3 with PE and in 2/3 patients with both DVT and PE. Radiotracer uptake was clearly detectable also in late scans, which confirms that 99mTc-P280 specifically binds to the thrombi through a receptor-mediated mechanism. PE localizations were detectable 3-4 hours after peptide injection, and in 2 cases SPECT enabled the detection of thrombi missed on planar views. Conversely, the test was negative in 4 patients who had the onset of clinical symptoms and the diagnosis of DVT and/or PE more than 40 days before scintigraphy. The lack of 99mTc-P280 uptake in the latter patients suggested that the peptide does not bind to thrombi when thrombogenesis is not active. These preliminary results clearly indicate scintigraphy with 99mTc-P280 to be a suitable, noninvasive and highly specific tool to image fresh clots causing DVT and/or PE. Thus, this technique might overcome the limitations of the imaging procedures currently in use.
 ...
PMID:[Imaging of thromboembolism by scintigraphy with the 99m-technetium-labelled synthetic peptide P280]. 868 69

1999 has been a good year in the field of innovation in thrombosis. In coronary syndrome without ST elevation: low molecular weight heparin has been confirmed to be more effective than non-fractionated heparin (enoxaparin) and to improve the prognosis of non-revascularised patients (dalteparin) after the hospital phase; hirudin has been shown to be more effective in terms of incidence of myocardial infarction and recurrence of angina than non-fractionated heparin without a higher incidence of bleeding complications; the anti-GP IIb-IIIa (abciximab) has confirmed all its advantages at 6 months and 1 year after a coronary event. The association of heparin and aspirin, which has been the mainstay of antithrombotic treatment of acute coronary syndromes without ST elevation, will soon be improved upon at the beginning of the third millennium. In myocardial infarction, medical thrombolysis has probably reached a turning point in its history. The association of half doses of rt-Pa and anti-GP IIb-IIIa has been shown to be more effective in obtaining good reflow than the thrombolytic agent alone at conventional doses. These results were obtained without any increase in bleeding complication. The same anti-GP IIb-IIIa also improve mechanical revascularisation by optimising reperfusion after the 24th hour. This benefit is rapidly transformed into reduced left ventricular dysfunction. Pulmonary embolism remains a critical illness as the ICOPER registry reports a 3 year mortality of nearly 16%. This emphasises the importance of early diagnosis which is usually possible without resorting to invasive procedures and by modulating all the results of paraclinical investigations with respect to the pretest clinical probability.
 ...
PMID:[The best of thrombosis and thromboembolic disease in 1999]. 1072 51

It is nearly impossible to follow and integrate all the new information in each subspeciality of cardiology. In the last months, important data has been published which may change clinical practice. In this domain, over half the cases of suspected coronary chest pain would only require a very short stay in a chest pain unit. The history, an accurate evaluation of symptoms, the application of Bayesian analysis, ECG interpretation and serum troponine measurement, associated with a degree of clinical experience, will allow orientation of the patient to a coronary care unit or hospital discharge (with possible out-patient referral). Patients with true unstable angina will no longer be treated by continuous intravenous injection of non-fractionated heparin because, in theory and in practice, this has been replaced with subcutaneous LMW heparin.... On the other hand, the electric syringe will continue to be required for the integration of the anti-GPIIB-IIIA for the treatment of unstable angina after the recommendations published concomitantly in the United States and Europe. This type of patient, especially with a "positive" troponine, will probably not be kept waiting long before referral to the catheter laboratory for coronary angiography and revascularisation. The long-term results of the FRISC II trial are confirmed by an even earlier invasive approach (Tactics-Timi 18) using anti-GPIIb-IIIa. In the first hours, and independently of other older prognostic factors, it will be possible to "predict or compare" the risk of coronary recurrence based on the results of certain biological "markers". In many centres, cases with ST elevation on the ECG could well be included in a phase III "medical protocol", associating a half-dose thrombolytic and an anti-GPIIb-IIIa. Finally, patients who will have been admitted to the chest pain unit with a suspected pulmonary embolism, for example because they had not been treated prophylactically with aspirin before hip surgery, will probably have the choice, after d-dimer measurement, between pulmonary scintigraphy and helicoidal CT scan. If the diagnosis of pulmonary embolism is confirmed, a single subcutaneous injection of LMW heparin could replace the conventional continuous intravenous injection of heparin. The earliest possible oral anticancer ... pardon me I anticoagulant treatment should be prescribed and explained.
 ...
PMID:[The best in 2000 on thrombosis]. 1126 Aug 41

Venous thrombosis and pulmonary embolism are major clinical problems that result in significant morbidity and mortality. It is estimated that 600,000 cases of pulmonary embolism occur each year in the United States, resulting in the death of approximately 100,000 patients. Most of these pulmonary emboli arise from deep venous thrombosis (DVT). The clinical diagnosis of DVT is unreliable. Only a third of patients with a clinical suspicion of DVT have objective evidence of the disease, and half of patients with proven DVT do not have any clinical symptoms. Although ascending contrast venography is the present standard for the diagnosis of DVT, duplex ultrasonography, which is increasingly used in combination with color Doppler flow imaging, is accepted as a useful clinical afternative to contrast venography. Both contrast venography and ultrasonography are imaging procedures that detect changes in venous anatomy that are caused by the presence of an intraluminal thrombus that is sufficiently formed either to reduce vascular filling with contrast medium or to resist compression. However, these imaging procedures do not reflect the metabolic activity of the clot, and therefore, they may overestimate the presence of active clots. The sensitivity of ultrasonography is also limited by various disease-related and technical factors. An alternative approach to the diagnosis of acute DVT is to detect a molecular marker of acute DVT that is not present in old, organized DVT. Recent advances in biotechnology permit the use of highly specific synthetic peptide or small molecular markers, which are involved in the acute stages of DVT formation and can be labeled efficiently with 99mTc. 99mTc-apcitide, a glycoprotein (GP IIb/IIIa) receptor antagonist previously known as 99mTc-P280, has been approved recently by the Food and Drug Administration for the clinical detection of acute DVT. Two other agents are currently under clinical investigation: 99mTc-DMP 444, which is another GP IIb/IIIa receptor antagonist, and 99mTc-Fibrin-Binding Domain (FBD), a radio-labeled fibrin-binding domain of fibronectin. Different clinical studies have shown a high diagnostic accuracy with these synthetic 99mTc-labeled peptides in the detection of acute DVT. Although further studies are needed to fully appreciate all of the diagnostic potential of these radiopharmaceuticals, the clinical introduction of 99mTcapcitide scintigraphy will certainly be helpful in expanding the use of nuclear medicine in a specific field in which it used to play a relatively marginal role.
 ...
PMID:Radiolabeled peptides in the detection of deep venous thrombosis. 1133 Jul 82

Identification of risk factors for incident venous thromboembolism and predictors of recurrent venous thromboembolism and appropriate antithrombotic prophylaxis and therapy are vital to improve survival after pulmonary embolism and prevent complications such as venous stasis syndrome after deep-vein thrombosis. Risk stratification is increasingly important; future prophylaxis and treatment strategies should be targeted to the patients who will derive the greatest benefit. For established antithrombotic agents, the most appropriate dose, dosing schedule, and duration of prophylaxis and therapy are being refined. In addition, new antithrombotic agents such as the oral direct thrombin inhibitors are being identified and developed. The management of acute arterial thrombosis (for example, acute coronary syndromes) is an important and relatively new indication for antithrombotic agents such as the low-molecular-weight heparins and the platelet glycoprotein IIb/IIIa antagonists.
 ...
PMID:Mapping out the future in venous thromboembolism and acute coronary syndromes. 1223 21

Excessive coagulation and impaired fibrinolysis lead to many hemostatic disorders, which enhance the risk of development of life-threatening cardiovascular diseases such as myocardial infarction, stroke, deep venous thrombosis and pulmonary embolism, belonging to the most important factors influencing morbidity and mortality in civilized societies. The adverse events induced by currently used drugs, the need for regular monitoring of coagulation parameters, inconvenient, in some cases, route of administration stimulate further search for novel, effective and safe methods of therapies of these disorders. In this paper, we describe those new agents which are now under experimental and clinical study, such us prostanoids, nitroaspirin, GP IIb/IIIa receptor antagonists, thienopyridine derivatives, collagen-GPVI and von Willebrand factor-GPIb-IX contact blockers, direct thrombin inhibitors, inhibitors of thrombin-platelet interactions, factor VII inhibitors and tissue factor-factor VII contact blockers. Based on the available literature, we discuss the possible role of these agents in the future prevention and treatment of thromboembolic diseases.
 ...
PMID:Progress in pharmacotherapy of thrombosis. 1458 10

A case of a 48-year-old woman with a comminuted fracture of the left tibia and receiving prophylactic doses of nadroparin, with massive pulmonary embolism mimicking ST-elevation acute coronary syndrome and complicated by cardiogenic shock and cardiac arrest, is presented. Pulmonary angiography showed total right pulmonary artery occlusion. Intraarterial thrombolysis with reduced dose of alteplase (50 mg), platelet GP IIb/IIIa blockade with eptifibatide, endovascular embolus fragmentation with a pigtail rotation catheter, and rescue pulmonary balloon angioplasty were performed, after which complete recovery was achieved. On day 4 of hospitalisation the patient was transferred to the orthopaedic ward where she underwent uneventful tibial surgery.
 ...
PMID:[Massive pulmonary embolism mimicking ST-elevation acute coronary syndrome successfully treated with hybrid therapy in a trauma patient receiving nadroparin: diagnostic and therapeutic dilemmas]. 1797 54

The importance of genetic thrombophilic factors in the development of venous thromboembolism has been increasingly recognized. Factor V Leiden (FVL), prothrombin gene mutation G20210A (FII G20210), genetic variant C677T of the methylentetrahydrofolate reductase (MTHFR), as well as the polymorphism A2 (PlA2) in platelet glycoprotein IIb/IIIa were recently discussed. We analyzed the contribution of genetic thrombophilic factors to the pathogenesis of pulmonary embolism (PE) and their association with the early onset and recurrence of PE using DNA analysis methods. In this case control trial we found thrombophilic genetic variants in 58.8% of 51 patients with PE. FVL was found in 23.5% of the patients versus 7.1% of the 98 controls (p=0.01), PlA2 IIb/IIIa was found in 35.3% vs. 14.3% (p=0.03), and FII G20210A was found in 5.9% vs. 2.0% (NS). Patients with recurrent PE had a very high prevalence of genetic factors, 70.4%. High prevalence of FVL was found in patients under 45 years of age: 39.3% (OR=14.23, 95% CI=1.58-330.03, p=0.01) as well as in patients with recurrent incidence (37%, OR=7.647, 95% CI=2.27-26.44, p=0.001). FVL was also significantly higher in the subgroup of patients with PE combined with deep venous thrombosis (OR=6.500, 95% CI=1.81-23.76, p=0.002) in comparison with patients with isolated PE (OR=2.261, 95% CI=0.50-9.69). The carriers of FVL are at higher risk for early and recurrent PE events. High prevalence of PlA2 in PE patients evidently shows the impact of this polymorphism in PE development. A different treatment should be considered in carriers of thrombophilic defects.
 ...
PMID:Impact of thrombophilic genetic factors on pulmonary embolism: early onset and recurrent incidences. 1809 19

DMP444 is a (99m)Tc-labeled cyclic RGD peptide, which has been evaluated in preclinical canine deep vein thrombosis (DVT) and pulmonary embolism (PE) models, and in patients with DVT and PE by SPECT (single photon emission computed tomography). Clinical data indicated that DMP444 is useful for imaging DVT, but it had limited utility for imaging PE in patients. To understand its clinical findings, we prepared a new radiotracer P4-DMP444 by replacing the lipophilic 6-aminocaproic acid (CA) in DMP444 with a highly water-soluble PEG(4) (15-amino-4,7,10,13-tetraoxapentadecanoic acid) linker. The objective of this study was to explore the impact of PEG(4) on biological properties (biodistribution, excretion kinetics, and capability to image thrombi) of (99m)Tc radiotracer. We also used canine DVT and PE models to perform imaging studies with/without the heparin pretreatment. These studies were specifically designed to explore the impact of heparin treatment on thrombosis uptake of P4-DMP444. It was found that replacing the CA linker with PEG(4) could enhance the radiotracer clearance kinetics from blood and normal organs in both rats and dogs. The fact that P4-DMP444 and DMP444 share very similar thrombosis uptake in both DVT and PE models suggests that the PEG(4) linker has little effect on GPIIb/IIIa binding affinity of cyclic RGD peptide. Even though P4-DMP444 had less accumulation than DMP444 in the blood, heart, lungs, and muscle over the 2 h study period in both rats and dogs, the difference in PE/lung and DVT/muscle ratios is marginal, suggesting that one PEG(4) linker is not sufficient to dramatically change the contrast between thrombus and background. It is very important to note that the heparin treatment of dogs with DVT and PE resulted in dramatic decrease in accumulation of P4-DMP444 in fresh thrombi. On the basis of these results, we believe that DMP444 and P4-DMP444 are excellent radiotracers for imaging both DVT and PE, and should be used in patients without antithrombosis treatment at the time of imaging.
 ...
PMID:Evaluation of 99mTc-labeled cyclic RGD peptide with a PEG4 linker for thrombosis imaging: comparison with DMP444. 2178 Aug 18


1 2 Next >>