Lysine-derivatized polyurethane as a clot lysing surface: conversion of adsorbed plasminogen to plasmin and clot lysis in vitro

summaryThe effect of purified human activated protein G (APC) on fibrinolysis was studied using a clot iysis system consisting of purified glu-plasminogen, tissue-type plasminogen activator, plasminogen activator inhibitor (released from endothelial cells or blood platelets), fibrinogen, 125T-fibrinogen and thrombin. All proteins were of human origin.In this system APC could increase fibrinolysis in a dose dependent way, without affecting fibrin formation or fibrin crosslinking. However, this profibrinolytic effect of APC could only be observed when plasminogen activator inhibitor (PAI-l) was present. The effect of APC was completely quenched by pretreatment of APC with anti-protein C IgG or di-isopropylfluorophosphate. Addition of the cofactors of APC:protein S, Ca2+-ions and phospholipid-alone or in combination did not enhance the profibrinolytic effect of APC. These observations indicate that human APC can accelerate in vitro clot lysis by the inactivation of PAI-1 activity. However, the neutralization of PAI-1 by APC is independent of the presence or absence of protein S, phospholipid and Ca2+-ions.

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Anti-thrombotic Effect of a PAI-1 Inhibitor in Rats Given Endotoxin

Thrombosis and Haemostasis ◽

10.1055/s-0038-1650231 ◽

1996 ◽

Vol 75 (01) ◽

pp. 118-126 ◽

Cited By ~ 27

Author(s):

T Abrahamsson ◽

V Nerme ◽

M Strömqvist ◽

B Åkerblom ◽

A Legnehed ◽

...

Keyword(s):

Plasminogen Activator Inhibitor ◽

Rat Plasma ◽

Clot Lysis ◽

Fibrin Deposition ◽

Plasminogen Activator Inhibitor 1 ◽

Fab Fragment ◽

Dose Dependent Decrease ◽

Pai 1

SummaryThe aim of this study was to investigate the anti-thrombotic effects of an inhibitor of the plasminogen activator inhibitor-1 (PAI-1) in rats given endotoxin. In studies in vitro, PRAP-1, a Fab-fragment of a polyclonal antibody against human PAI-1, was shown to inhibit PAI-1 activity in rat plasma as well as to stimulate clot-lysis of the euglobulin fraction derived from rat plasma. Endotoxin administered to anaesthetised rats produced a marked increase in plasma PAI-1 activity. To study fibrin formation and lysis in vivo after intravenous (i. v.) injection of the coagulant enzyme batroxobin, 125I-fibrinogen was administered to the animals. The thrombi formed by batroxobin were rapidly lysed in control animals, while the rate of lysis was markedly attenuated in rats given endotoxin. PRAP-1 was administered i.v. (bolus + infusion) to rats given endotoxin and batroxobin and the PAI-1 inhibitor caused a dose-dependent decrease in the 125I-fibrin deposition in the lungs. An immunohistochemical technique was used to confirm this decrease in density of fibrin clots in the tissue. Furthermore, PRAP-1 decreased plasma PAI-1 activity in the rats and this reduction was correlated to the decrease in lung 125I-fibrin deposition at the corresponding time point. It is concluded that in this experimental model the PAI-1 antibody PRAP-1 may indeed inhibit thrombosis in animals exposed to endotoxin.

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The Roles of α2-Antiplasmin and Plasminogen Activator Inhibitor 1 (PAI-1) in the Inhibition of Clot Lysis

Thrombosis and Haemostasis ◽

10.1055/s-0038-1649570 ◽

1993 ◽

Vol 70 (02) ◽

pp. 301-306 ◽

Cited By ~ 51

Author(s):

Linda A Robbie ◽

Nuala A Booth ◽

Alison M Croll ◽

Bruce Bennett

Keyword(s):

Plasminogen Activator ◽

Plasminogen Activator Inhibitor ◽

Fibrin Clot ◽

Clot Lysis ◽

Plasminogen Activator Inhibitor 1 ◽

Dependent Inhibition ◽

Activator Inhibitor ◽

Pai 1

SummaryThe relative importance of the two major inhibitors of fibrinolysis, α2-antiplasmin (α2-AP) and plasminogen activator inhibitor (PAI-1), were investigated using a simple microtitre plate system to study fibrin clot lysis in vitro. Cross-linked fibrin clots contained plasminogen and tissue plasminogen activator (t-PA) at concentrations close to physiological. Purified α2-AP and PAI-1 caused dose-dependent inhibition. All the inhibition due to normal plasma, either platelet-rich or poor, was neutralised only by antibodies to α2-AP. Isolated platelets, at a final concentration similar to that in blood, 2.5 × 108/ml, markedly inhibited clot lysis. This inhibition was neutralised only by antibodies to PAI-1. At the normal circulating ratio of plasma to platelets, α2-AP was the dominant inhibitor. When the platelet:plasma ratio was raised some 20-fold, platelet PAI-1 provided a significant contribution. High local concentrations of PAI-1 do occur in thrombi in vivo, indicating a role for PAI-1, complementary to that of α2-AP, in such situations.

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Dependence of Blood Clot Lysis on the Mode of Transport of Urokinase into the Clot - A Magnetic Resonance Imaging Study in Vitro

Thrombosis and Haemostasis ◽

10.1055/s-0038-1648188 ◽

1991 ◽

Vol 65 (05) ◽

pp. 549-552 ◽

Cited By ~ 55

Author(s):

A Blinc ◽

G Planinšič ◽

D Keber ◽

O Jarh ◽

G Lahajnar ◽

...

Keyword(s):

Magnetic Resonance Imaging ◽

Magnetic Resonance ◽

Pressure Difference ◽

Volume Flow Rate ◽

Blood Clot ◽

Linear Regression Analysis ◽

Imaging Study ◽

Clot Lysis ◽

Resonance Imaging

SummaryMagnetic resonance imaging was employed to study the dependence of clot lysing patterns on two different modes of transport of urokinase into whole blood clots. In one group of clots (nonperfused clots, n1 = 10), access of urokinase to the fibrin network was possible by diffusion only, whereas in the other group (perfused clots, n2 = 10) bulk flow of plasma containing urokinase was instituted through occlusive clots by a pressure difference of 3 .7 kPa (37 cm H2O) across 3 cm long clots with a diameter of 4 mm. It was determined separately that this pressure difference resulted in a volume flow rate of 5.05 ± 2.4 × 10−2 ml/min through occlusive clots. Perfused clots diminished in size significantly in comparison to nonperfused ones already after 20 min (p <0.005). Linear regression analysis of two-dimensional clot sizes measured by MRI showed that the rate of lysis was more than 50-times faster in the perfused group in comparison to the nonperfused group. It was concluded that penetration of the thrombolytic agent into clots by perfusion is much more effective than by diffusion. Our results might have some implications for understanding the differences in lysis of arterial and venous thrombi.

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In Vitro Clot Lysis as a Potential Indicator of Thrombus Resistance to Fibrinolysis – Study in Healthy Subjects and Correlation with Blood Fibrinolytic Parameters

Thrombosis and Haemostasis ◽

10.1055/s-0038-1656041 ◽

1997 ◽

Vol 77 (04) ◽

pp. 725-729 ◽

Cited By ~ 11

Author(s):

Mario Colucci ◽

Silvia Scopece ◽

Antonio V Gelato ◽

Donato Dimonte ◽

Nicola Semeraro

Keyword(s):

Plasminogen Activator ◽

Clot Lysis ◽

Individual Response ◽

Plasminogen Activator Inhibitor 1 ◽

Autologous Plasma ◽

Wide Range ◽

Blood Clots ◽

Physiological Variations ◽

Pai 1

SummaryUsing an in vitro model of clot lysis, the individual response to a pharmacological concentration of recombinant tissue plasminogen activator (rt-PA) and the influence on this response of the physiological variations of blood parameters known to interfere with the fibrinolytic/thrombolytic process were investigated in 103 healthy donors. 125I-fibrin labelled blood clots were submersed in autologous plasma, supplemented with 500 ng/ml of rt-PA or solvent, and the degree of lysis was determined after 3 h of incubation at 37° C. Baseline plasma levels of t-PA, plasminogen activator inhibitor 1 (PAI-1), plasminogen, α2-anti-plasmin, fibrinogen, lipoprotein (a), thrombomodulin and von Willebrand factor as well as platelet and leukocyte count and clot retraction were also determined in each donor. rt-PA-induced clot lysis varied over a wide range (28-75%) and was significantly related to endogenous t-PA, PAI-1, plasminogen (p <0.001) and age (p <0.01). Multivariate analysis indicated that both PAI-1 antigen and plasminogen independently predicted low response to rt-PA. Surprisingly, however, not only PAI-1 but also plasminogen was negatively correlated with rt-PA-ginduced clot lysis. The observation that neutralization of PAI-1 by specific antibodies, both in plasma and within the clot, did not potentiate clot lysis indicates that the inhibitor, including the platelet-derived form, is insufficient to attenuate the thrombolytic activity of a pharmacological concentration of rt-PA and that its elevation, similarly to the elevation of plasminogen, is not the cause of clot resistance but rather a coincident finding. It is concluded that the in vitro response of blood clots to rt-PA is poorly influenced by the physiological variations of the examined parameters and that factors other than those evaluated in this study interfere with clot dissolution by rt-PA. In vitro clot lysis test might help to identify patients who may be resistant to thrombolytic therapy.

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Inhibition of the Activities of α2-Plasmin inhibitor (PI) and CI inhibitor (CI-Inh) by the Synthetic Fibrinolytic Agent, 3-Hydroxypropyl Flufenamide (Flu-HPA)

10.1055/s-0038-1665785 ◽

1979 ◽

Author(s):

L Miles ◽

J Burnier ◽

M Verlander ◽

M Goodman ◽

A Kleiss ◽

...

Keyword(s):

Plasminogen Activators ◽

Inhibitory Effect ◽

Mechanisms Of Action ◽

Flufenamic Acid ◽

Clot Lysis ◽

Factor Xiia ◽

Dependent Inhibition ◽

Normal Human ◽

Plasmin Inhibitor

Flu-HPA is one of a series of flufenamic acid derivations that enhances plasminogen-dependent clot lysis in vitro. Studies of possible mechanisms of action of Flu-HPA were undertaken. The influence of Flu-HPA on the inhibition of purified plasmin by purified PI was studied. PI activity was assessed by its inhibition of the clevage of the tripeptide S-2251 (H-D-Val-Leu-Lys-pNA) by plasmin. Flu-HPA was dissolved in DMF or in methonol and preincubated with PI before addition of plasmin. At Flu-HPA concentrations greater than 1mM and up to 60mM, the inhibitory activity of PI was totally lost. The inhibitory effect of normal human plasma on plasmin was also completely abolished at concentrations of Flu-HPA between 2.5 and 40mM. The effect of Flu-HPA on the inhibition of purified plasma kallikrein by purified CI-Inh was also studied. CI-Inh activity was measured by its inhibition of cleavage of the tripeptide Bz-Pro-Phe-Arg-pNA by kallikrein. When Flu-HPA, dissolved in DMF or in methonol, was preincubated with CI-Inh, a concentration dependent inhibition of CI-Inh activity was observed. CI-Inh activity was abolished by concentrations of Flu-HPA greater than 1mM. Flu-HPA also inhibited the activity of CI-Inh on purified Factor XIIa. These observations suggest that this flufenamic acid derivative may enhance fibrinolysis not only by inhibiting PI activity but also by decreasing the inactivation of plasminogen activators by CI-Inh.

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Absence of Synergism Between Tissue-Type Plasminogen Activator (t-PA), Single-Chain UrokinaseType Plasminogen Activator (scu-PA) and Urokinase on Clot Lysis in a Plasma Milieu In Vitro

Thrombosis and Haemostasis ◽

10.1055/s-0038-1661598 ◽

1986 ◽

Vol 56 (01) ◽

pp. 035-039 ◽

Cited By ~ 42

Author(s):

D Collen ◽

F De Cock ◽

E Demarsin ◽

H R Lijnen ◽

D C Stump

Keyword(s):

Human Plasma ◽

Plasminogen Activator ◽

Dose Response ◽

Fibrinolytic System ◽

Tissue Type ◽

Clot Lysis ◽

Single Chain ◽

Tissue Type Plasminogen Activator ◽

Type Plasminogen Activator

SummaryA potential synergic effect of tissue-type plasminogen activator (t-PA), single-chain urokinase-type plasminogen activator (scuPA) or urokinase on clot lysis was investigated in a whole human plasma system in vitro. The system consisted of a human plasma clot labeled with 125I-fibrinogen, immersed in titrated whole human plasma, to which the thrombolytic agents were added. Clot lysis was quantitated by measurement of released 125I, and activation of the fibrinolytic system in the surrounding plasma by measurements of fibrinogen and α2-antiplasmin.t-PA, scu-PA and urokinase induced a dose-dependent and time-dependent clot lysis; 50 percent lysis after 2 h was obtained with 5 nM t-PA, 20 nM scu-PA and 12 nM urokinase. At these concentrations no significant activation of the fibrinolytic system in the plasma was observed with t-PA and scu-PA, whereas urokinase caused significant α2-antiplasmin consumption and concomitant fibrinogen degradation. The shape of the dose-response curves was different; t-PA and urokinase showed a log linear dose-response whereas that of scu-PA was sigmoidal.

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Optimal Initial Positioning of Chest Tubes to Prevent Retained Hemothorax Using a Novel Steerable Chest Tube With Extendable Infusion Cannula

Military Medicine ◽

10.1093/milmed/usaa295 ◽

2021 ◽

Vol 186 (Supplement_1) ◽

pp. 324-330

Author(s):

John B Fortune ◽

Serena Murphy ◽

Kimberley Tiller

Keyword(s):

Chest Tube ◽

Animal Studies ◽

Training Session ◽

Penetrating Trauma ◽

Pleural Space ◽

Tube Placement ◽

Clot Lysis ◽

Retained Hemothorax ◽

Tip Position

ABSTRACT Introduction With blunt and penetrating trauma to the chest, warfighters and civilians frequently suffer from punctured lung (pneumothorax) and/or bleeding into the pleural space (hemothorax). Optimal management of this condition requires the rapid placement of a chest tube to evacuate as much of the blood and air as possible. Incomplete drainage of blood leading to retained hemothorax may be the result of the final tube tip position not being in contact with the blood collections. To address this problem, we sought to develop a “steerable” chest tube that could be accurately placed or repositioned into a specific desired position in the pleural space to assure optimal drainage. An integrated infusion cannula was added for the instillation of anticoagulants to maintain tube patency, thrombolytics for clot lysis, and analgesics for pain control if required. Materials and Methods A triple-lumen tube was designed to provide a channel for a pull-wire which was wound around an axle integrated into a small proximal handle and controlled by a ratcheted thumbwheel. Tension on the wire creates an arc on the tube that allows for positioning. In vitro testing focused on the relationship between the tension on the pull-wire and the resultant arc. Two adult cadavers and two anesthetized pigs were used to study the feasibility of accurate tube placement. After a brief training session, providers were asked to place tubes inferiorly along the diaphragm where blood was anticipated to accumulate or at the apex of the lung for pneumothorax. Success was determined with fluoroscopic images and was judged as a tube tip lying in the targeted position. Results The design was prototyped with an extruded polyvinyl chloride multilumen tube and a 3D printed tensioning handle. In vitro studies showed that one turn of the thumbwheel created 70° to 90° of arc of the tube. Cadaver and animal studies showed consistent success in the desired placement of the tube at or near the lateral diaphragm or in the apex. Attempts were also successful by surgical residents with minimal training. Conclusions Initial preliminary studies on a novel steerable chest tube have demonstrated the ability to appropriately position the tube in a desired location. The addition of an extendable cannula will allow for safe clot lysis or maintained tube patency. Additional studies are planned to confirm the benefit of this device in preventing retained hemothorax.

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Nanodroplet-mediated catheter-directed sonothrombolysis of retracted blood clots

Microsystems & Nanoengineering ◽

10.1038/s41378-020-00228-9 ◽

2021 ◽

Vol 7 (1) ◽

Author(s):

Leela Goel ◽

Huaiyu Wu ◽

Bohua Zhang ◽

Jinwook Kim ◽

Paul A. Dayton ◽

...

Keyword(s):

Drug Delivery ◽

Negative Pressure ◽

Boiling Point ◽

Clot Lysis ◽

Control Group ◽

Peak Negative Pressure ◽

Blood Clots ◽

Tissue Plasminogen ◽

First Time

AbstractOne major challenge in current microbubble (MB) and tissue plasminogen activator (tPA)-mediated sonothrombolysis techniques is effectively treating retracted blood clots, owing to the high density and low porosity of retracted clots. Nanodroplets (NDs) have the potential to enhance retracted clot lysis owing to their small size and ability to penetrate into retracted clots to enhance drug delivery. For the first time, we demonstrate that a sub-megahertz, forward-viewing intravascular (FVI) transducer can be used for ND-mediated sonothrombolysis, in vitro. In this study, we determined the minimum peak negative pressure to induce cavitation with low-boiling point phase change nanodroplets and clot lysis. We then compared nanodroplet mediated sonothrombolysis to MB and tPA mediate techniques. The clot lysis as a percent mass decrease in retracted clots was 9 ± 8%, 9 ± 5%, 16 ± 5%, 14 ± 9%, 17 ± 9%, 30 ± 8%, and 40 ± 9% for the control group, tPA alone, tPA + US, MB + US, MB + tPA + US, ND + US, and ND + tPA + US groups, respectively. In retracted blood clots, combined ND- and tPA-mediated sonothrombolysis was able to significantly enhance retracted clot lysis compared with traditional MB and tPA-mediated sonothrombolysis techniques. Combined nanodroplet with tPA-mediated sonothrombolysis may provide a feasible strategy for safely treating retracted clots.

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Therapeutic Potentials of Syzygium fruticosum Fruit (Seed) Reflected into an Array of Pharmacological Assays and Prospective Receptors-Mediated Pathways

Life ◽

10.3390/life11020155 ◽

2021 ◽

Vol 11 (2) ◽

pp. 155

Author(s):

Jannatul Nasma Rupa Moni ◽

Md. Adnan ◽

Abu Montakim Tareq ◽

Md. Imtiazul Kabir ◽

A.S.M. Ali Reza ◽

...

Keyword(s):

Bioactive Compounds ◽

Integrated Approach ◽

Gas Chromatography Mass Spectrometry ◽

Clot Lysis ◽

Lipinski’S Rule ◽

Lysis Activity ◽

In Silico Studies ◽

Immobility Time

Syzygium fruticosum (SF), a valuable Bangladeshi fruit, is considered an alternative therapeutic agent. Mainly, seeds are used as nutritional phytotherapy to ease physical and mental status by preventing chronic diseases. Here, we scrutinized the S. fruticosum seed’s fundamental importance in traditional medicine by following an integrated approach combining in vivo, in vitro, and in silico studies. The SF was fractionated with different solvents, and the ethyl acetate fraction of SF (EaF-SF) was further studied. Mice treated with EaF-SF (200 and 400 mg/kg) manifested anxiolysis evidenced by higher exploration in elevated plus maze and hole board tests. Similarly, a dose-dependent drop of immobility time in a forced swimming test ensured significant anti-depressant activity. Moreover, higher dose treatment exposed reduced exploratory behaviour resembling decreased movement and prolonged sleeping latency with a quick onset of sleep during the open field and thiopental-induced sleeping tests, respectively. In parallel, EaF-SF significantly (p < 0.001) and dose-dependently suppressed acetic acid and formalin-induced pain in mice. Also, a noteworthy anti-inflammatory activity and a substantial (p < 0.01) clot lysis activity (thrombolytic) was observed. Gas chromatography-mass spectrometry (GC–MS) analysis resulted in 49 bioactive compounds. Among them, 12 bioactive compounds with Lipinski’s rule and safety confirmation showed strong binding affinity (molecular docking) against the receptors of each model used. To conclude, the S. fruticosum seed is a prospective source of health-promoting effects that can be an excellent candidate for preventing degenerative diseases.

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