• Journal of Korean Neurosurgical Society
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• v.46 no.3
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• pp.277-280
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• 2009

Posterior cranial fossa subdural hematomas and extension of the subdural hematoma to the cerebellopontine angle is rarely seen and the concurrent development of acute peripheral facial palsy and the management strategy have not previously been reported in this pathology because of its rarity. We present this case to emphasize that minor head trauma may lead to a posterior cranial fossa hematoma extending to the cerebellopontine angle and cause peripheral facial palsy in patients using aspirin (acetylsalicylic acid). In addition, partial evacuation and waiting for the resorption of the hematoma may help to prevent damage to the 7th and 8th cranial nerves.

• YAKHAK HOEJI
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• v.58 no.5
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• pp.322-327
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• 2014

In this study, we investigated whether the mixtures of onion water extract and aloe ethanol extracts have antiplatelet activities. The mixtures inhibited collagen- and thrombin-induced rat platelet aggregation in vitro. Additionally, the oral administration of the mixtures inhibited platelet aggregation induced by collagen ex vivo but not prolonged mouse tail vein bleeding time in vivo. These results suggest that the combination of onion and aloe extracts has a potential to be a preventive agent against platelet-mediated disorders.

• Journal of Medicine and Life Science
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• v.20 no.3
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• pp.131-134
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• 2023

Here, we present a case of a 56-year-old man with acute myocardial infarction. The patient underwent percutaneous coronary intervention (PCI) at the left main bifurcation and mid-left anterior descending artery using drugeluting stents. Four months after the PCI, the patient was readmitted for cardiac arrest. Coronary angiography (CAG) revealed stent thrombosis in the left main-to-proximal left anterior descending artery and in-stent restenosis in the left main-to-proximal left circumflex artery. We performed balloon angioplasty at the left main to mid-left anterior descending artery and left main to proximal left circumflex artery stents; subsequently, blood flow was fully restored. However, contrast agent extravasation was observed outside the mid-portion of the left main artery to the proximal left anterior descending artery stent, indicating the presence of a coronary artery aneurysm (CAA) outside the stent. After guideline-directed medical therapy with dual antiplatelet agents and high-intensity statins, follow-up CAG revealed near-resolution of the CAA, absence of stenotic lesions, and good blood flow.

• Biomolecules & Therapeutics
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• v.18 no.2
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• pp.205-210
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• 2010

Several studies have shown that plant-derived polyphenols reduce cardiovascular accidents in high-risk patients and the inhibition of platelet function may be responsible for part of this benefit. Lindera obtusiloba is widely used in traditional herbal medicine for the treatment of cardiovascular and inflammatory diseases. Therefore, the antiplatelet and antithrombotic activities of Lindera obtusiloba Extracts (LOE) on in vitro platelet aggregation, radical scavenging activity and in vivo murine pulmonary thrombosis were examined. LOE was able to directly scavenge the stable DPPH radical in a concentration-dependent manner and its $IC_{50}$ value was 3.9 ${\pm}$ 0.1 ${\mu}g$/ml. LOE significantly inhibited collagen- and ADP-induced platelet aggregation in a concentration-dependent manner and its $IC_{50}$ value is 0.9 ${\pm}$ 0.1 mg/ml and 0.4 ${\pm}$ 0.1 mg/ml respectively. The inhibitory effect of LOE was comparable to aspirin ($IC_{50}$ values were 1.0 ${\pm}$ 0.5 and 1.0 ${\pm}$ 0.7 mg/ml, respectively). Furthermore, oral administration of LOE suppressed the death of mice with pulmonary thrombosis induced by intravenous injection of collagen plus epinephrine. Taken together, our results suggest LOE may be a promising candidate for antithrombotic agent, and the antithrombotic effect of LOE may be due to, at least in part, antiplatelet activity.

• Journal of Chest Surgery
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• v.28 no.8
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• pp.754-758
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• 1995

Between February 1987 and April 1994,30 modified Blalock- Taussing shunts[MBTS were carried out at the Department of Thoracic and Cardiovascular Surgery of the Keimyung University Dongsan Medical Center.The operation consists of interposing between the subclavian artery and the pulmonary artery a polytetrafluoroethylene graft.There were 19 boys and 11 girls.The average age at the time of shunt construction was 14 months [range 4 days to 5 years .Seventy-six percent [23/30 were less than 1 year of age.Cardiac defects treated with MBTS included tetralogy of Fallot[10 , pulmonary atresia with ventricular septal defect[8 , pulmonary atresia with intact ventricular septum[4 , uni-ventricular heart[3 , and other complex cardiac anomalies[5 .Prosthesis of 4mm were used in 13 cases, and 5mm in 17.Of the 30 operations, 21 were performed on the right side and 9 on the left side.The hemoglobin level decreased from 21.1 gm/dl preoperatively to 16.3 gm/dl postoperatively and systemic oxygen saturation level increased from 60.5 % preoperatively to 85.4 % postoperatively.In the 30 patients who recieved MBTS, there were one early [3% and three late deaths [10% .Seven patients have had an corrective operation and two patient required second palliative procedure.The remaining patients are awaiting further operation with ingestion of aspirin [5 mg/kg/day as an antiplatelet agent.These results indicate that the MBTS provide excellent palliation at a low operative mortality for most patients.

• Journal of Applied Biological Chemistry
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• v.63 no.2
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• pp.131-136
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• 2020

When blood vessels are damaged, a fast hemostatic response should occur to minimize blood loss and maintain normal circulation. Platelet activation and aggregation are essential in this process. However, excessive platelet aggregation or abnormal platelet aggregation may be the cause of cardiovascular diseases such as thrombosis, stroke, and atherosclerosis. Therefore, finding a substance capable of regulating platelet activation and suppressing agglutination reaction is important for the prevention and treatment of cardiovascular diseases. 6,7-Dimethoxy-2H-chromen-2-one (Scoparone), found primarily in the roots of Artemisia or Scopolia plants, has been reported to have a pharmacological effect on immunosuppression and vasodilation, but studies of platelet aggregation and its mechanisms are still insufficient. This study confirmed the effect of scoparone on collagen-induced human platelet aggregation, TXA₂ production, and major regulation of intracellular granule secretion (ATP and serotonin release). In addition, the effect of scoparone on the phosphorylation of the phosphoproteins PI3K/Akt and mitogen-activated protein kinases (MAPK) involved in signal transduction in platelet aggregation was studied. As a result, scoparone significantly inhibited the phosphorylation of PI3K/Akt and MAPK, which significantly inhibited platelet aggregation through TXA₂ production and intracellular granule secretion (ATP and serotonin release). Therefore, we suggest that scoparone is an antiplatelet substance that regulates the phosphorylation of phosphoproteins such as PI3K/Akt and MAPK and is of value as a preventive and therapeutic agent for platelet-derived cardiovascular disease.

• Journal of Applied Biological Chemistry
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• v.63 no.3
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• pp.235-241
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• 2020

An essential component of the hemostatic process during vascular damage is platelet activation. However, many cardiovascular diseases, such as atherosclerosis, thrombosis, and myocardial infarction, can develop due to excessive platelet activation. Isoscopoletin, found primarily in plant roots of the genus Artemisia or Scopolia, has been studied to demonstrate potential pharmacological effects on Alzheimer's disease and anticancer, but its mechanisms and role in relation to thrombus formation and platelet aggregation have not yet been discovered. This research investigated the effect of isoscopoletin on collagen-induced human platelet activation. As a result, isoscopoletin strongly increased cyclic adenosine monophosphate (cAMP) and cyclic guanosine monophosphate (cGMP) levels in a concentration-dependent manner. In addition, isoscopoletin greatly phosphorylated inositol 1,4,5-triphosphate receptor (IP₃R) and vasodilator-stimulated phosphoprotein (VASP), known substrates of cAMP-dependent kinase and cGMP dependent kinase. Phosphorylation of IP₃R by isoscopoletin induced Ca²⁺ inhibition from the dense tubular system Ca²⁺ channels, and VASP phosphorylation was involved in fibrinogen binding inhibition by inactivating αIIb/β₃ in the platelet membrane. Isoscopoletin finally reduced thrombin-induced fibrin clot production and finally reduced thrombus formation. Therefore, this research suggests that isoscopoletin has strong antiplatelet effects and is likely to be helpful for thrombotic diseases involving platelets by acting as a prophylactic and therapeutic agent.

• Childhood Kidney Diseases
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• v.14 no.1
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• pp.10-21
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• 2010

The overall prognosis of Henoch-Schoenlein purpura (HSP) is favorable, but severe nephritis has a high risk of progression to end stage renal failure. Recent studies emphasize the importance of early treatment in children with severe HSP nephritis, but the treatment of severe HSP nephritis still remains controversial due to the rarity of randomized controlled studies in this field. Nevertheless, several intensive therapies, such as intravenous high-dose methylprednisolone pulse, immunosuppressive/cytotoxic drugs, fibrinolytic therapy, anticoagulants, antiplatelet agent and plasma exchange, have been used in children with severe HSP nephritis. In this review, we focus on the treatment of severe HSP nephritis in children.

• Proceedings of the PSK Conference
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• 2003.10b
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• pp.110.3-111
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• 2003

In the previous studies, we have reported that NQ30l, a synthetic l,4-naphthoquinone derivative, displayed a potent antithrombotic activity, and that this might be due to antiplatelet effect, which was mediated by inhibition of cytosolic $Ca^{2+}$ mobilization in activated platelets. In the present study, the effect of NQ301 on arachidonic acid cascade in activated platlets was examined. NQ301 concentration-dependently inhibited washed rabbit platelet aggregation induced by collagen (10 $\mu$g/ml), arachidonic acid (100 $\mu$M) and U46619 (1 $\mu$M), a thromboxane $A_2$receptor agonist, with $IC_50$ values of 0.60$\pm$0.02, 0.79$\pm$0.04 and 0.58$\pm$0.04 $\mu$M, respectively. (omitted)

• Journal of Applied Biological Chemistry
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• v.65 no.3
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• pp.167-172
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• 2022

Pathophysiological reaction of platelets in the blood vessel is an indispensable part of thrombosis and cardiovascular disease, which is the most common cause of death in the world. In this study, we performed in vitro assays to evaluate antiplatelet activity of artemether in human platelets and attempted to identify the mechanism responsible for protein phosphorylation. Artemether is a derivative of artemisinin, known as an active ingredient of Artemisia annua, which has been reported to be effective in treating malaria, and is known to function through antioxidant and metabolic enzyme inhibition. However, the role of artemether in platelet activation and aggregation and the mechanism of action of artemether in collagen-induced human platelets are not known until now. In this study, the effect of artesunate on collagen-induced human platelet aggregation was confirmed and the mechanism of action of artemether was clarified. Artemether inhibited the phosphorylation of PI3K/Akt and Mitogen-activated protein kinases, which are phosphoproteins that are known to act in the signal transduction process when platelets are activated. In addition, artemether decreased TXA₂ production and decreased granule secretion in platelets such as ATP and serotonin release. As a result, artemether strongly inhibited platelet aggregation induced by collagen, a strong aggregation inducer secreted from vascular endothelial cells, with an IC₅₀ of 157.92 μM. These results suggest that artemether has value as an effective antithrombotic agent for inhibiting the activation and aggregation of human platelets through vascular injury.