• Journal of Biomedical Engineering Research
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• v.27 no.5
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• pp.267-273
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• 2006

Numerical analysis was performed on the enzyme transport and the flow fields in order to predict the effectiveness of urokinase injection regimens in clot dissolution. The species and momentum transport equations were numerically solved for the case of uniform perfusion of enzyme into a fibrin clot for an arterial thrombus and a deep vein thrombus models. In order to predict the thrombus lysis efficiency of continuous and forced intermittent injections, enzyme perfusion and clot lysis were simulated for the different injection velocities. Intermittent injection showed faster clot lysis compared to continuous perfusion, and lysis efficiency was increased as injection velocity increased.

• International Journal of Vascular Biomedical Engineering
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• v.4 no.2
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• pp.13-18
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• 2006

Direct injection of a fibrinolytic agent to the intra-arterial thrombosis may increase the effectiveness of thrombolysis by enhancing the permeation of thrombolytic agents into the blood clot. Permeation of fibrinolytic agents into a clot is influenced by the surface pressure, which is determined by the injection velocity of fibrinolytic agents. Computational fluid dynamic methods were used in order to predict clot lysis for different jet velocities and nozzle arrangements. Firstly, thrombolysis of a clot was mathematically modeled based on the pressure and lysis front velocity relationship. Direct injection of a thrombolytic agent increased the speed of thrombolysis significantly and the effectiveness was increased as the ejecting velocity increased. The nine nozzles model showed about 20% increase of the lysed volume, and the one and seventeen nozzles models did not show significant differences. Secondly, thrombolysis was modeled based on the enzyme transport and the fluid flow equations, and quasi steady numerical analysis was performed. Clot lysis efficiency was also increased as injection velocity increased.

• Journal of the Korean Society for Precision Engineering
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• v.26 no.7
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• pp.22-30
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• 2009

• Journal of Biomedical Engineering Research
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• v.26 no.3
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• pp.157-161
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• 2005

Direct injection of a fibrinolytic agent to the intraarterial thrombosis may increase the effectiveness of thrombolysis by enhancing the permeation of thrombolytic agents into the blood clot. Permeation of fibrinolytic agents into a clot is influenced by the surface pressure, which is determined by the injection velocity of fibrinolytic agents. In order to calculate the pressure distribution on the clot surface for different jet velocities (1, 3, 5 m/sec) and nozzle arrangements (1, 9, 17 nozzles), computational fluid dynamic methods were used. Thrombolysis of a clot was mathematically modeled based on the pressure and lysis front velocity relationship. Direct injection of a thrombolytic agent increased the speed of thrombolysis significantly and the effectiveness was increased as the ejecting velocity increased. The nine nozzles model showed about $20\%$ increase of the lysed volume, and the one and seventeen nozzles models did not show significant differences. The wall shear stress decreased as the number of nozzles increased, and the wall shear stress in most vessel wall was lower than 25 Pa. The results implied that thrombolysis could be accelerated by direct injection of a drug with the moderate velocity without damaging the blood vessel wall.

• Journal of Life Science
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• v.19 no.2
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• pp.289-298
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• 2009

Effects of Nattokinase fibrinol (NKF), defined as a fibrinolytic product, on fibrinolytic and atherogenetic markers were studied for healthy adults (20-31 years old), who is smoking more than 20 cigarettes per day. Subjects were divided into 29 for NKF group and 10 for placebo group in a short term study. They were given 2 tablets of NKF (4,000 unit) or placebo tablet and thereafter blood samples were collected at 0, 2, 4 hr prerid. For a 4-week long term study, 15 subjects for NFK group and 10 subjects for placebo group were supplemented one tablet of each NKF (2,000 unit) and placebo per day, respectively. Blood samples were collected at 0, 1, 2, 4 weeks later. The short-term experimental trial showed that NKF remarkably increased fibrinolytic activity at 2hr after consumption, which was maintained up to 4 hr, relative to that of placebo, while NKF reduced the euglobulin clot lysis time (ECLT) and retarded the activated partial thromboplastin time (aPTT), as compared to placebo group. NKF supplementation for 4 weeks elevated fibrinolytic activity, shortened ECLT and retarded aPTT. Furthermore, NKF supplementation increased anti-atherogenic index by decreasing triglyceride (TG) and elevating high-density lipiprotein (HDL)-cholesterol. These results indicate that NKF supplementation for short term or long term might have beneficial effects on preventing and treating cardiovascular disease by increasing fibrinolytic activity and improving atherogenic markers such as hyperlipidemia.

• Preventive Nutrition and Food Science
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• v.17 no.1
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• pp.78-82
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• 2012

Antithrombotic and fibrinolytic activity of natto was evaluated on platelet aggregation in vitro and in vivo. Natto showed inhibitory effects on platelet aggregation induced by adenosine 5’diphosphate (ADP) and collagen. Orally administered natto also showed fibrinolytic activity in hypercholesterolemia rats. Normal levels of natto, when administered for four weeks, shortened euglobulin clot lysis time (ECLT) and prolonged partial thromboplastin time (PATT) significantly compared to non-treated group. In addition, the natto treatment decreased total cholesterol in serum. These results showed that intake of normal levels of natto can elicit antithrombotic and fibrinolytic effects, suggesting its consumption may improve blood circulation.

• Journal of Chest Surgery
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• v.21 no.5
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• pp.911-917
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• 1988

Pulmonary thromboembolism originated most commonly from the venous thrombus, especially deep vein thrombus in the leg, which migrated to and occluded the pulmonary vasculatures. The failure of clot lysis and repeated embolic episodes resulted in the hemodynamic compromise -that is- in the increasing in the pulmonary vascular resistance, which would cause the right ventricle failure[Car Pulmonale]. Under the cardiopulmonary bypass, 20 year old male patient was treated successfully by thromboembolectomy of pulmonary thromboembolism with pulmonary hypertension, which originated from the deep vein thrombus in the leg. The results of radiologic studies and clinical evaluations were excellent in that the postoperative lung perfusion scan showed the newly increased perfusion of post-embolectomy territories and in the arterial blood gas finding of 76 from 66[mmHg] in PaO2. The patient was uneventful and discharged on postop. $ 14 days with anticoagulant continued.

• Proceedings of the Korea Environmental Mutagen Society Conference
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• 2004.05a
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• pp.93-93
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• 2004

• KSBB Journal
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• v.27 no.6
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• pp.375-380
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• 2012

We previously reported that Ultra nattokinase$^{(R)}$ showed high fibrinolytic activity and revealed antithrombotic effect in rat blood plasma based on its ability to suppress collagen-induced platelet aggregation. This research was carried out to verify the clot lysing activity and blood flow enhancing effects of Ultra nattokinase$^{(R)}$ via monitoring and comparing the antithrombotic effects in rat artery between oral administration of Ultra nattokinase$^{(R)}$ and maltodextrin. SD rats were fed with 1.11 mg/kg of Ultra nattokinase$^{(R)}$ for 4 weeks. The effect on arterial thrombosis was then evaluated using an antithrombotic model after induction by $FeCl_3$. Detected fibrinolytic activity was proportional to the content of Ultra nattokinase$^{(R)}$ and statistical extents of the antithrombotic activity was enhanced strongly twice rather than control group. The PT and the aPTT, however, showed only a small difference between two groups. The results suggest that Ultra nattokinase$^{(R)}$ can effectively treat thromboembolism and enhance blood flow, and that Ultra nattokinase$^{(R)}$ can also prevent venous occlusion by aiding clot lysis.

• Journal of Korean Neurosurgical Society
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• v.37 no.4
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• pp.287-292
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• 2005

Objective: Recent clinical studies have demonstrated that intracisternal administration of recombinant tissue plasminogen activator(rt-PA) can facilitate the normal clearing of blood from the subarachnoid space. Urokinase, a first generation fibrinolytic agent, has been used to liquify such clots with some success. Therefore, recombinant tissue plasminogen activator, a second generation fibrinolytic drug that may be safer and more effective, is studied to evaluate its dosage to lyse clots in vitro and reactivity in the brain parenchyme. Methods: Intracerebral hematomas were created by stereotactically injecting 2ml of clotted autogenous blood into the brain parenchyme of total 28 anesthetized adult cats (weighting 3.8 to 4.1 kg). The control animals (group A) received 1 ml of normal saline injected into the clots and the experimental animals received each 0.1 mg of rt-PA (group B), 0.5mg of rt-PA (group C) and 1 mg of rt-PA (group D) at 6 hours after the clot injection. Results: 1. The amount of remained clots after lysing the hematomas were as follows: $1.80{\pm}0.17ml$ in group A, $1.65{\pm}0.23ml$ in group B, $0.61{\pm}0.37ml$ in group C and $0.52{\pm}0.34$ in group D. The result indicated that hematomas in rt-PA treated groups (C & D) were lysed better than the control group. 2. At least 0.5mg of rt-PA should be required for the lysis of 2ml of hematomas. 3. Light microscopic examination revealed no histological evidence of hemorrhage in tissue sections from each brain. Conclusion: Recombinant tissue plasminogen activator may be safely and effectively employed for the lysis of intracerebral hematomas in animal model.