• Title/Summary/Keyword: Fibrinolysis

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Alternative Mechanism of Aspirin in Anti-Thrombotic Therapy: Inhibition of Thrombin Activatable Fibrinolysis Inhibitor

  • An, Seong-Soo A.;Greenfield, Robert S.
    • Bulletin of the Korean Chemical Society
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    • v.33 no.9
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    • pp.3048-3054
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    • 2012
  • The use of aspirin is widely recommended for the prevention of heart attacks owing to its ability to inhibit platelet activation by irreversibly blocking cyclooxygenase 1. However, aspirin also affects the fibrinolytic and hemostatic pathways by mechanisms that are not well understood, causing severe hemorrhagic complications. Here, we investigated the ability of aspirin and aspirin metabolites to inhibit thrombin-activatable fibrinolysis inhibitor (TAFI), the major inhibitor of plasma fibrinolysis. TAFI is activated via proteolytic cleavage by the thrombin-thrombomodulin complex to TAFIa, a carboxypeptidase B-like enzyme. TAFIa modulates fibrinolysis by removing the C-terminal arginine and lysine residues from partially degraded fibrin, which in turn inhibits the binding of plasminogen to fibrin clots. Aspirin and its major metabolites, salicylic acid, gentisic acid, and salicyluric acid, inhibit TAFIa carboxypeptidase activity. Salicyluric acid effectively blocks activation of TAFI by thrombin-thrombomodulin; however, salicylates do not inhibit carboxypeptidase N or pancreatic carboxypeptidase B. Aspirin and other salicylates accelerated the dissolution of fibrin clots and reduced thrombus formation in an in vitro model of fibrinolysis. Inhibition of TAFI represents a novel hemostatic mechanism that contributes to aspirin's therapy-associated antithrombotic activity and hemorrhagic complications.

Detecting Activated Thrombin Activatable Fibrinolysis Inhibitor (TAFIa) and Inactivated TAFIa (TAFIai) in Normal and Hemophilia A Plasmas

  • Hulme, John P.;An, Seong Soo A.
    • Bulletin of the Korean Chemical Society
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    • v.30 no.1
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    • pp.77-82
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    • 2009
  • Thrombin activatable fibrinolysis inhibitor (TAFI) also known as plasma procarboxypeptidase B or U is a 60 kD glycoprotein, which is the major modulator of fibrinolysis in plasma. TAFI is a proenzyme, which is activated by proteolytic cleavage to an active carboxypeptidase B-like enzyme (TAFIa, 35.8 kD) by thrombin/thrombomodulin and plasmin. Modulation of fibrinolysis occurs when TAFIa enzymatically removes C-terminal lysine residues of partially degraded fibrin, thereby inhibiting the stimulation of tissue plasminogen activator (t-PA) modulated plasminogen activation. TAFIa undergoes a rapid conformational change at $37{^{\circ}C}$ to an inactive isoform called TAFIai. Potato tuber carboxypetidase inhibitor (PTCI) was shown to specifically bind to TAFIa as well as TAFIai. In this study, a novel immunoassay TAFIa/ai ELISA was used for quantitation of the two TAFI activation isoforms TAFIa and TAFIai. The ELISA utilizes PTCI as the capture agent and a double antibody sandwich technique for the detection. Low levels of TAFIa/ai antigen levels were detected in normal plasma and elevated levels were found in hemophilia A plasmas. TAFIa/ai antigen represents a novel marker to monitor fibrinolysis and TAFIa/ai ELISA may be a valuable assay for studying the role of TAFI in normal hemostasis and in pathological conditions.

Long-term clinical outcome of acute myocardial infarction according to the early revascularization method: a comparison of primary percutaneous coronary interventions and fibrinolysis followed by routine invasive treatment

  • Min, Hyang Ki;Park, Ji Young;Choi, Jae Woong;Ryu, Sung Kee;Kim, Seunghwan;Song, Chang Sup;Kim, Dong Shin;Song, Chi Woo;Kim, Se Jong;Kim, Young Bin
    • Journal of Yeungnam Medical Science
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    • v.34 no.2
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    • pp.191-199
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    • 2017
  • Background: This study was conducted to provide a comparison between the clinical outcomes of primary percutaneous coronary intervention (PCI) and that of fibrinolysis followed by routine invasive treatment in ST elevation myocardial infarction (STEMI). Methods: A total of 184 consecutive STEMI patients who underwent primary PCI or fibrinolysis followed by a routine invasive therapy were enrolled from 2004 to 2011, and their major adverse cardiovascular events (MACEs) were compared. Results: Among the 184 patients, 146 patients received primary PCI and 38 patients received fibrinolysis. The baseline clinical characteristics were similar between both groups, except for triglyceride level ($68.1{\pm}66.62$ vs. $141.6{\pm}154.3mg/dL$, p=0.007) and high density lipoprotein level ($44.6{\pm}10.3$ vs. $39.5{\pm}8.1mg/dL$, p=0.005). The initial creatine kinase-MB level was higher in the primary PCI group ($71.5{\pm}114.2$ vs. $35.9{\pm}59.9ng/mL$, p=0.010). The proportion of pre-thrombolysis in MI 0 to 2 flow lesions (92.9% vs. 73.0%, p<0.001) was higher and glycoprotein IIb/IIIa inhibitors were administered more frequently in the primary PCI group. There was no difference in the 12-month clinical outcomes, including all-cause mortality (9.9% vs. 8.8%, p=0.896), cardiac death (7.8% vs. 5.9%, p=0.845), non-fatal MI (1.4% vs. 2.9%, p=0.539), target lesion revascularization (5.7% vs. 2.9%, p=0.517), and stroke (0% vs. 0%). The MACEs free survival rate was similar for both groups (odds ratio, 0.792; 95% confidence interval, 0.317-1.980; p=0.618). The clinical outcome of thrombolysis was not inferior, even when compared with primary PCI performed within 90 minutes. Conclusion: Early fibrinolysis with optimal antiplatelet and antithrombotic therapy followed by appropriate invasive procedure would be a comparable alternative to treatment of MI, especially in cases of shorter-symptom-to-door time.

A Study on the isolation and characteristics of fibrinolysis-related enzymes from Holotrichia extract (제조의 혈전(血栓) 용해(溶解) 효소(酵素) 분리(分離) 및 그 특성(特性)에 관한 연구(硏究))

  • Hong, Shi-Nae;Jeong, Ji-Cheon;Kim, Cheol-Ho
    • The Journal of Internal Korean Medicine
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    • v.20 no.1
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    • pp.198-209
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    • 1999
  • A thrombus is a mass formed from the constituents of the blood within the vessels or the heart during life. The process of its formation is known as thrombosis, It has been generally accepted that Holotrichia is an useful medicine for thrombosis. The rate of fibrinolysis of Holotrichia extracts increase as incubation times. Especially 52 days, the effect on the extracts has an maximum increased fibrinolytic activity, Heat-and-pH-stability of the extract on fibrinolysis is relative to temperature, At $37^{\circ}C$, it has activating effect between pH 4 and pH 12. At higher temperature, especially $80^{\circ}C$, an excessive increase in temperature has a deactivating effect on the extracts. Optimal pH of the extract on fibrinolysis is between pH 7.0 and pH 8.5, it is effective within a relatively broad pH range. In experiments of various inhibitors of Holotrichia extracts fibrinolytic activity, there are strong inhibitive effect on SBTI and Aprotinin, and a few inhibitive effect on DFP and t-AMCHA, no effect on PSMB and TLCK. Holotrichia extracts mixing with fibrinogen are observed Electron microscopy. it shows partially erosive-shaped fibrinolytic activity. In a SDS-PAGE of the extract having the fibrinolytic activity, three bands are found, protein 1, 2 and 3 having a molecular weight of 30,000, 45,000 and 60,000 Dalton.

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Dry Socket Etiology, Diagnosis, and Clinical Treatment Techniques

  • Mamoun, John
    • Journal of the Korean Association of Oral and Maxillofacial Surgeons
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    • v.44 no.2
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    • pp.52-58
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    • 2018
  • Dry socket, also termed fibrinolytic osteitis or alveolar osteitis, is a complication of tooth exodontia. A dry socket lesion is a post-extraction socket that exhibits exposed bone that is not covered by a blood clot or healing epithelium and exists inside or around the perimeter of the socket or alveolus for days after the extraction procedure. This article describes dry socket lesions; reviews the basic clinical techniques of treating different manifestations of dry socket lesions; and shows how microscope level loupe magnification of $6{\times}$ to $8{\times}$ or greater, combined with co-axial illumination or a dental operating microscope, facilitate more precise treatment of dry socket lesions. The author examines the scientific validity of the proposed causes of dry socket lesions (such as bacteria, inflammation, fibrinolysis, or traumatic extractions) and the scientific validity of different terminologies used to describe dry socket lesions. This article also presents an alternative model of what causes dry socket lesions, based on evidence from dental literature. Although the clinical techniques for treating dry socket lesions seem empirically correct, more evidence is required to determine the causes of dry socket lesions.

Genetic Polymorphisms of t-PA and PAI-1 Genes in the Korean Population

  • Kang, Byung-Yong;Lee, Kang-Oh
    • Animal cells and systems
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    • v.7 no.3
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    • pp.249-253
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    • 2003
  • Abnormalities in fibrinolysis system is associated with risk of hypertension. In this report, the Alu repeat insertion/deletion (I/D) polymorphism of tissue plasminogen activator (t-PA) and the Hind III RFLP of plasminogen activator inhibitor-1 (PAI-1) genes were investigated in 115 normotensives and 83 patients with hypertension, and their association with anthropometrical data and plasma biochemical parameters were analyzed. There were no significant differences in the gene frequencies of the two candidate genes between normotensives and hypertensives, respectively. Our results indicate lack of associations between the two polymorph isms in t-PA and PAI-1 genes and risk of hypertension in the population under study. However, the Hind III RFLP of PAI-1 gene was significantly associated with plasma glucose level, suggesting its role in glucose metabolism. It needs to be tested whether this RFLP of PAI-1 gene is associated with insulin resistance syndrome or non-insulin dependent diabetes mellitus (NIDDM) in the Korean population.

A Case of Spontaneous Remission of Acute Pulmonary Embolism (자연 소실된 급성 폐색전증 1예)

  • Lee, Jae-Joon;Lee, Min-Ji;Park, Hyo;Zeon, Seok-Jae;Lim, Young-Min;Song, Sang-Hee;Na, Dong-Jib;Kim, Eun-Jin
    • Tuberculosis and Respiratory Diseases
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    • v.72 no.2
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    • pp.232-235
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    • 2012
  • Acute pulmonary embolism (PE) ranges from asymptomatic to often fatal, incidentally discovered emboli to massive embolism causing immediate death. Acute PE may occur rapidly and unpredictably and may be difficult to diagnose. Mortality and complications can be reduced by prompt diagnosis and therapy. Untreated PE is associated with a mortality rate of approximately 30 percents. Most patients with PE have endogenous fibrinolysis, although it is not effective enough to prevent PE. A case of spontaneous remission of untreated acute PE has not previously been reported. Here we present a case of spontaneously resolved acute PE without any treatment.

Effects of Insect Crude Drugs on Blood Coagulation and Fibrinolysis System

  • Ahn, Mi-Young;Hahn, Bum-Soo;Ryu, Kang-Sun;Cho, Sung-Ig
    • Natural Product Sciences
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    • v.8 no.2
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    • pp.66-70
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    • 2002
  • The in vitro anticoagulant and fibrinolytic activities of crude extracts from insects were evaluated in order to find effective therapeutic drugs for the treatment of myocardial and cerebral thrombosis. We prepared three types of extracts (water, methanol and ethylacetate) from 28 insects for use as raw materials for the activity assays. The fibrinolytic activity was tested using the fibrin plate method and the activated partial thromboplastin time and thrombin time were measured for blood clotting activity. With regards to the fibrinolytic system, water extracts of six kinds of insects displayed a remarkable level of activity with a plasmin-like action. The water extracts of [Catharsius molossus, Eupolyphaga sinensis, Huechys sanguinea, Mantidis $o\ddot{o}theca$, Mimela splendens, and Polistes mandarinus (Vespae Nidus)] exhibited the activity. On the other hand, the methanol extracts did not display any fibrinolytic activity. In terms of the coagulation system, an aqueous extract of silkworm Tongchunghacho (Paecilomyces japonica), Oxya japonica japonica and Buthus martensi (Scorpion) increased the clotting time significantly longer (181 times) than the control. These results suggest that crude drugs from insects are useful sources for the development of new drugs for use in treatments involving blood coagulation and fibrinolysis.