• Journal of Life Science
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• v.21 no.10
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• pp.1355-1363
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• 2011

Many clinical trials have demonstrated the beneficial effects of garlic (Allium sativum) on general cardiovascular health. Aged garlic extract (AGE) is known to display diverse biological activities such as in antioxidant, anti-inflammatory and anticancer activities. However, few studies have been directed on the effect of AGE on cardiovascular function. In this study, we aimed to investigate the effect of AGE and its components on platelet activation, a key contributor in thrombotic diseases. In freshly isolated rat platelets, AGE and its components have shown inhibitory activities on thrombin-induced platelet aggregation. These in vitro results were further confirmed in an in vivo platelet aggregation measurement where tail vein injection of garlic oil and S-Allylmercapto-cysteine (SAMC) significantly reduced thrombin and ADP-induced platelet aggregation. Potential active components for antiplatelet effects of AGE were identified to be SAMC and diallyl sulphide through agonist-induced platelet aggregation assay. These results indicate that aged garlic extract can be a novel dietary supplement for the prevention of cardiovascular risks and the improvement of blood circulation.

• Biomedical Science Letters
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• v.10 no.4
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• pp.391-395
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• 2004

The demand for the production of gene-defective mice from embryonic stem (ES) cells is increasing to clarify decisive gene function in vivo. Although blastocyst injection is widely used to generate ES cell-mediated knockout mice, coculture method has been alternatively used because of several advantages, such as low cost and simple procedure. Thus, this experiment was designed to demonstrate the feasibility of the coculture method using J1 ES cells, which are known to be efficient for blastocyst injection. Eight-cell embryos were harvested from 2.5 days post-coitum (dpc), denuded with acid tyrode's solution, and transferred onto trypsinized J1 ES cells. Aggregation was carried out following two typical methods, which are simple coculture method and aggregation in groove prepared by aggregation needle. Successfully aggregated-embryos were developed to blastocysts for 24 h and transferred into uterus of pseudo-pregnant foster mother. Chimeric offspring was judged by coat pigmentation. In this study, we could obtain chimeric mice from all the two aggregation methods, but the chimera production efficiencies in coculture using groove were three times higher at least than those in the other group. In conclusion, these observations suggest that coculture method should be available for production of knockout mice from J1 ES cells. Presently, the germ-line transmission rates of the chimeras produced from the two methods are under investigation.

• ETRI Journal
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• v.24 no.4
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• pp.323-327
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• 2002

In this study, we propose a novel mobile tracking method based on Multi-Criteria Decision Making (MCDM), in which uncertain parameters-the received signal strength, the distance between the mobile and the base station, the moving direction, and the previous location-are used in the decision process using the aggregation function in the fuzzy set theory. Through numerical results, we show that our proposed mobile tracking method provides a better performance than the conventional method using the received signal strength.

• The Korean Journal of Pharmacology
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• v.20 no.1 s.34
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• pp.41-46
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• 1984

Cadmium (Cd) was administered by a series of weekly intraperitoneal injections at dose of 2mg/kg in rabbits and rats. The levels of malondialdehyde (MDA) and thromboxane $B^2(TXB_2)$ in platelet-rich plasma from Cd-poisoned animals were significantly higher than those of the control group. Furthermore, the inhibition of 6-keto-prostaglandin $F_{1{\alpha}}$, production in Cd-treated aorta ring was inversely related to the enhancement of platelet aggregation. These results suggest that Cd not only inhibits prostacyclin synthesis in the arterial endothelium, but also stimulates the platelet aggregation by enhancing thromboxane AZ production. These findings are assumed to support the evidence of an effect of Cd toxicity on the vascular wall and platelet function in raising arteriall pressure.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.44 no.8
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• pp.33-41
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• 2007

The IEEE 802.11 DCF channel access function allows single transmission inside two-hop network in order to avoid collisions and eliminate the hidden and exposed terminal problems. Singular transmission capability causes data frames waiting for the entire roundtrip time in the transmitter neighborhood, and results in increased frame latency and lower network throughput. Real-time and pervasive applications are severely affected for the lower medium utilization; especially with high network traffic. This work proposes a new scheme with the help of Frame Aggregation technique in IEEE802.11n and overcomes the single transmission barrier maintaining the basic DCF functionality. Proposed scheme allows parallel transmissions in non-interfering synchronized slots. Parallel transmissions bypass the conventional physical carrier sense and random Backoff time for several cases and reduce the frame latency and increase the medium utilization and network capacity.

• Biomedical Science Letters
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• v.21 no.4
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• pp.188-197
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• 2015

In this study, we investigated the effect of rice bran water extract fermented with Lactobacillus plantarum Hong (RBLw), on activities of cyclooxygenase-1 (COX-1) and thromboxane $A_2$ synthase (TXAS), thromboxane $A_2$ ($TXA_2$) production associated microsomal enzymes and evaluated its the antiplatelet effect. RBLw, containing 13.5 mg of ferulic acid, dose-dependently inhibited ADP-induced platelet aggregation, and inhibited the production of $TXA_2$, an aggregation molecule. In addition, RBLw directly inhibited COX-1 activity in a dose-dependent manner, but not TXAS activity in platelet microsomal fraction having cytochrome c reductase (an endoplasmic reticulum marker enzyme) activity and expressing COX-1 (72 kDa) and TXAS (60.5 kDa) proteins. These results suggest that RBLw selectively inhibited the activity of COX-1 rather than TXAS to attenuate $TXA_2$ production in ADP-activated platelets. Thus, we demonstrate that RBLw might have direct COX-1 antagonistic function for platelet aggregation-mediated diseases, such as thrombosis, myocardial infarction, atherosclerosis, and ischemic cerebrovascular disease.

• The Journal of Korean Medicine
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• v.23 no.2
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• pp.164-179
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• 2002

Object: Death rate due to hypertension, atherosclerosis, ischemic heart disease and cerebral infarction induced by Westernized diet and increased average life span is on the rise. Decrease in blood circulation, activation of thrombus generation and intravascular lipid accumulation, cited as the principal causes of the above mentioned diseases in recent studies, result in circulatory disturbance and blood vessel obstruction leading to ischemic cell death of heart, brain and peripheral vessels. Method: We investigated the biochemical changes in microvascular permeability, aggregation of platelet and the intravascular lipid accumulation in induced-diabetic rat using Streptozotocin. We also studied the effects of Woohwangcheongsirn-won after oral administration on blood circulation, platelet function and lipid metabolism. The results are as follows: I. Woohwangcheongsim-won increased blood circulation in microvessels. 2. Woohwangcheongsim-won increased the reduced erythrocyte deformability in diabetes. 3. Woohwangcheongsim-won induced the reduction of contents of 2, 3-DPG, but failed to affect the reduced contents of ATP in erythrocyte in diabetes. 4. Woohwangcheongsim-won reduced the activity of Ca/sup 2+/-ATPase in the membrane of erythrocyte. 5. Woohwangcheongsim-won reduced the platelet aggregation evoked by platelet agglutinin factor. 6. Woohwangcheongsim-won reduced the production of platelet-derived granules. 7. Woohwangcheongsim-won reduced the production of metabolites of arachidonic acid in diabetes, and also reduced the production of increased thromboxane B2. 8. Woohwangcheongsim-won reduced the synthesis of oxidized LDL-cholesterol. In conclusion, Woohwangcheongsim-won enhanced blood circulation in microvesseles, erythrocyte deformability and inhibited the increased platelet aggregation and the synthesis of oxidized LDL-cholesterol in diabetes. Therefore Woohwangcheongsim-won is believed to positively affect blood circulation (J Korean Oriental Med 2002;23(2):164-179)

• Biomedical Science Letters
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• v.24 no.3
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• pp.280-284
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• 2018

The incidence of cardiovascular diseases (CVDs) is increasing rapidly in developed countries, with CVDs now representing the leading cause of morbidity and mortality. Natural products and ethnomedicines have been shown to reduce the risk of CVDs. Garlic is a medicinal plant used throughout the world for its anti-inflammatory, antioxidant, and antiplatelet activities. Chitosan is a natural polysaccharide obtained from chitin, and derivatives of chitosan have been shown to inhibit platelet aggregation and adhesion. We hypothesized that fermented preparations of these products may possess stronger antiplatelet effects than the non-fermented forms owing to the increased bioavailability of the bioactive compounds produced during fermentation. Therefore, we compared these compounds via in vitro and ex vivo platelet aggregation assays by using standard light transmission aggregometry and ex vivo granule secretions from rat platelets. We found that fermented preparations exerted more potent and significant inhibition of platelet aggregation both in vitro and ex vivo. Likewise, ATP release from dense granules of platelets was also significantly inhibited in fermented preparation-treated rat platelets compared to that in non-fermented preparation-treated ones. We concluded that fermented preparations exerted more potent effects on platelet function both in vitro and ex vivo, possibly as a result of the increased bioavailability of active compounds produced during fermentation. We therefore suggest that fermented products may be potent therapeutics against platelet-related CVDs and can be used as antiplatelet and antithrombotic agents.

• Journal of Chest Surgery
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• v.19 no.1
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• pp.35-42
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• 1986

Prevention of thrombombolism after rosthetic cardiac valve replacement is essential for the patients. About 90% of patients are free of major and minor thromboembolic complications 5 year after replacement of cardiac valves with prosthetic devices when they are under control of anticoagulant therapy. Ticlopidine is a drug that alter platelet function to have an antithrombotic effect. It is an antiaggregating agent which inhibits primary platelet function to have an antithrombotic effect. It is an antiaggregating agent which inhibits primary platelet aggregation induced by ADP and increases the production of prostaglandin $D_{2}$. Aspirin in small doses inhibits platelet synthesis of prostaglandins by irreversibly blocking the enzyme cyclo-oxygenase. Platelet secretion and aggregation are impaired with Ticlopidine and Aspirin. the thromboembolic event sof 54 patient s who were treated with Ticlopidine and Aspirin after cardiac valve replacement were evaluated and compared with that of 79 patients who were treated with Wafarin and Aspirin after the same type of operation. The follow-up period ranged from 4 to 110 months (mean of 48 months). there were 11 major thromboembolic episodes including three deaths in the warfarin goup during mean follow-up period of 56 months. two cases of CVA and one hemoarthrosis were noted due to overdose of Warfarin. Inticlopidine group, there was only one fatal thromboembolic epdisode three month after mitral valve replacement during mean follow-up period of 18 months. Two episodes of hypermenorrhea resulting anemia ere noted in the ticlopidine group. We measured the parameters of platelet function in aggreagation curve of platelet with platelet aggregometer (chrono-log Aggregometer, Model No. 430) Aggregation test was performed with three final concentrations of epinephrine in 10 uM/L, ADP in 5uM/L. 28 patients with prosthetic cardiac valves and 35 healthy volunteers were subgrouped as follows to analyze the effect of antithrombotic drugs used. Group I ; 11 patients treated with 250-500 mg of ticlopidine and 0.5gm of Aspirin as a daily single dose after cardiac valve replacement (14 St. Jude Medical and 1 Carpentier-Edwards, 9 patients with atrial fibrillation among them) Group II ; 10 patients treated with 3-5 mg of Warfarin and 0.75 gm of Aspirin daily to prolong prothrombin time around 20 seconds for more than 6 months and single Aspirin dose was maintained afterward as a life-long regimes(3 St. Jude Medical, 1 Hall-Kaster and 7 Carpentier-Edwards valve, 9 patients in atrial fibrilation). Group III ; 7 patients who quit anticoagulant treatment (Warfarin + Aspirin) 6-12 months after the regime as group II (3 St. Jude Medical. 1 bjork-Shiley, 1 Hall-Kaster, 3 Carpentier-Edwards valve, 2 of them are with atrial fibrillation). Group IV ; 35 healthy vounteers (28 males and 7 females). The following results were obtained. 1. The mean maximal platelet aggregability in Group I induced by 10uM/L epinephrine was 15.6%, and 17.5 and 18.7% in BM in proportion to the induction by 5 and 10 uM/L ADP. 2. The mean maximal platelet aggregability in Group II induced by 10uM/L epinephrine was 16.5%, and 27.4 and 44.7% in BM in proportion to the induction by 5 and 10uM/L ADP. 3. The mean maximal platelet aggregability in group III induced by 10uM/L epinephrine was 65%, and 56.5 and 51.8% in BM in proportion to the induction by 5 and 10 uM/L ADP. 4. The mean maximal platelet aggregability in the normal subjects induced by 10 uM/L epinephrine was 64%, and 65 and 69% in Bm inproportion to the induction by 5 and 10 uM/L ADP. 5. Reversible change of platelet aggregation curve induced by 5 and 10uM/L was noted all of the patients in Group I. conclusion : Ticlopidine is an antiaggregating agent which inhibits primary platelet aggregation induced by ADP, and increases the production of prostaglandin $D_{2}$. Ticlopidine and Aspirin produced a significant inhibition of platelet in the presence of ADP and epinephrine in our study. Acccording to our brief experience, 250 mg of ticlopidine and low dose of Aspirin resulted synergistic superior effect to each drug alone in prevention of thromboembolism after prosthetic cardiac valve replacement.

• Journal of Veterinary Clinics
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• v.40 no.5
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• pp.330-335
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• 2023

Platelet function evaluation by PFA-100 or -200 has been known to be objective and sensitive for assessing platelet function and dysfunction of Von Willebrand Factor in humans and dogs. However, using the C/EPI cartridge in dogs is controversial. This study aimed to establish a reference range for PFA closure time in healthy small breed dogs (body weight < 10 kg) and to evaluate the effectiveness of both C/ADP and C/EPI cartridges for these dogs. Citrated blood samples were collected from 50 clinically healthy small breed dogs that were admitted for presurgical procedures or health checkups, and closure times were measured using the PFA-200. Reference ranges were determined as 42-144 s (median 67 s, mean 71.2 s, SD ± 21.2 s, 95% RI 43-140 s) , for CT-C/ADP and 41-200 s (median 87, mean 91.2 s, SD ± 31.8 s, 95% RI 44-195 s) for CT-C/EPI. The present study demonstrated that the reference ranges for PFA closure times in small breed dogs are in line with existing reference ranges. The utilization of C/ADP cartridges is the preferred choice for evaluating platelet function in small breed dogs. However, due to variable responses of epinephrine to platelet aggregation in dogs, caution should be exercised when using C/EPI cartridges.