• The Korean Journal of Physiology and Pharmacology
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• v.4 no.6
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• pp.515-523
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• 2000

Polymorphonuclear leukocytes (PMNs) play an important role in myocardial ischemia/reperfusion (MI/R) injury. Moreover, platelets are also important blood cells that can aggravate myocardial ischemic injury. This study was designed to test the effects of PMNs and platelets separately and together in provoking cardiac dysfunction in isolated perfused rat hearts following ischemia and reperfusion. Additional control rat hearts were perfused with $75{\times}10^6$ PMNs, with $75{\times}10^6$ platelets, or with $75{\times}10^6\;PMNs+75{\times}10^6$ platelets over a five minute perfusion followed by a 75 min observation period. No significant reduction in coronary flow (CF), left ventricular developed pressure (LVDP), or the first derivative of LVDP (dP/dt max) was observed at the end of the observation period in any non-ischemic group. Similarly, global ischemia (I) for 20 min followed by 45 minutes of reperfusion (R) produced no sustained effects on the final recovery of any of these parameters in any group of hearts perfused in the absence of blood cells. However, I/R hearts perfused with either PMNs or platelets alone exhibited decreases in these variables of $5{\sim}10%$ (p＜0.05 from control). Furthermore, I/R hearts perfused with both PMNs and platelets exhibited decreases of 50 to 60% in all measurements of cardiac function (p＜0.01). These dual cell perfused I/R hearts also exhibited marked increases in cardiac myeloperoxidase (MPO) activity indicating a significant PMN infiltration, and enhanced P-selectin expression on the coronary microvascular endothelium. All cardiaodynamic effects as well as PMN accumulation and P-selectin expression were markedly attenuated by a recombinant soluble PSGL-1 which inhibits selectin mediated cell adhesion. These results provide evidence that platelets and PMNs act synergistically in provoking post-reperfusion cardiac dysfunction, and that this may be largely due to cell to cell interactions mediated by P-selectin. These results also demonstrate that a recombinant soluble PSGL-1 reduces myocardial reperfusion injury by platelet and PMNs interaction.

• 제어로봇시스템학회:학술대회논문집
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• 2002.10a
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• pp.77.1-77
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• 2002

Platelets arrest bleeding and repair damaged blood vessels. The purpose of this paper is to formulate a mathematical model for the control of platelet adhesion within the vasculature consistent with experimental findings, particularly those of Frenette, Ruggeri , Savage, Yuan, Lawrence and Springer. In addition to providing some, albeit rudimentary, insight into the behavior of platelets, a numerical simulation of this theoretical model may be useful in a systematic study of pathological cases. Glycoprotein receptor complex (GPIb/V/IX), found on the platelet surface membrane, binds to the adhesive protein and ligand von Willebrand factor (vWf), located within the sub-endothelium. The binding...

• Journal of Physiology & Pathology in Korean Medicine
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• v.17 no.4
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• pp.930-938
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• 2003

The purpose of the present study was to investigate the effects of Hyunhosaiksan (HHS) on antithrombotic actions which include blood activation, thrombus removal, warming of circulating blood, and the control of pain on abdomen and lower and upper burning spaces. HHS significantly inhibited platelet aggregation induced by ADP and epinephrine in a HHS dose-dependent manner when analyzed by the Sigmoid Emax model in WinNonlin. EC50 values of HHS were 1.71 ㎍/ml and 0.004 ㎍/ml for ADP and epinephrine respectively. In the vivo study, HHS inhibited pulmonary embolism induced by collagen and epinephrine, which was however statistically insignificant. HHS increased number of platelets, APTT and volume of fibrinogen significantly as compared with the control group in dextran-induced thrombus model. Furthermore, HHS stimulated levels of blood flow in vivo though its effect was not observed in vitro. These results suggest that Hyunhosaiksan (HHS) can be used for treating numerous diseases related with blood aggregation and circulation problems. Further systematic investigations on the synergic effects among drugs used in the oriental medicine as well as in the western medicine in relation to thrombosis therapy would provide an important insight into the potential therapeutic applications.

• The Journal of Korean Medicine
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• v.16 no.1 s.29
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• pp.351-369
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• 1995

In order to investigate the effect of Qingbaozhuyutang(淸胞逐瘀湯), Bee Veenom on 'Blood Stasis Pattern', here We regard Thrombosis and Elevated Blood viscosity as Blood Stasis Pattern. rats were injected Endotoxin into the caudal vein to make experimental thrombosis model(control group), and at sample group, rats were orally administrated solid extract of Qingbaozhuyutang(淸胞逐瘀湯) 0.5g/200g or were injected Apitoxin 1mg/Kg into the abdominal region(sample group), and then we observed platelet, fibrinogen, prothrombin time and FDP level. Another group were injected HA into the muscular rump to make experimental elevated blood viscosity instead of Endotoxin. Thereafter we measured whole blood viscosity and plasma viscosity. The results were summarized as follows. 1. Platelets were increased significantly in sample I compared with the control group. 2. Fibrinogen levels were increased significantly in sample I compared with the control group. 3. Prothrombin times were shortened significantly in sample II and sample III compared with the control group. 4. FDP levels were decreased significantly in sample II and sample III compared with the control group. 5. Whole blood viscosity and plasma viscosity were decreased significantly in all shear rates compared with the control group. According to the above results, it is considered that Qingbaozhuyutang(淸胞逐瘀湯) has significant effects on platelets, fibrinogens, prothrombin times, FDP levels, whole blood viscosity and plasma viscosities, therefore it seems to be applicable to disease related to 'Blood Stasis Pattern' through the thrombosis and elevated blood viscosity. But, Veenom has a little effect. the mechanism concerned for the effects is to be investigated in future.

• Journal of Biomedical Engineering Research
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• v.8 no.2
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• pp.199-204
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• 1987

ABA type block copolymers composed of r benzyle L-glutamate as the A component and poly(ethylene glycol) as the B components were obtained. Platelet adhesion on their sunfaces was investigated by a column elusion method to examine the effects of microdomain and secondary structure. The number of platelets adhered from whole blood and plasma rich platelet was smaller for the block copolymer systems than for the homopolymers. In the block copolymer system, the number of platelets adrered on their surfaces increased with increasing the content of PEG, that is, with decreasing of a-helix of block copolymers. A thick thrombus formation on the PBLG homopolymer was observed than block copolymer by scanning electron micrographs. The platelets adhesion increased with increasing the critical surface tension of the block copolymer.

• Proceedings of the KAIS Fall Conference
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• 2004.06a
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• pp.253-257
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• 2004

Platelet aggregation is a complex phenomenon that probably involves several intracellular biochemical pathways. When activated, platelets change shape, aggregate and release the contents of their intracellular granules. The interactions between platelets and blood vessel walls are important in the development of thrombosis and cardiovascular diseases. When blood vessels are damaged, platelet aggregation occurs rapidly to form haemostatic Plugs or arterial thrombi at the sites of vessel injury or in regions where blood flow is disturbed. These thrombi are the source of thromboembolic complications of atherosclerosis, heart attacks, stroke, and peripheral vascular disease. Therefore, the inhibition of platelet function represents a promising approach for the prevention of thrombosis. Plants constitute a rich source of bioactive chemicals such as phenolics, terpenoids and alkaloids. Plant extracts may be an alternative to currently used medicinal source because they constitute a rich source of bioactive chemicals. This study was performed to investigate the antiplatelet activity of extract of Tabebuia impetiginosa Martius ex DC (Taheebo) and find out which fractions to this activity in rabbit platelet. Taheebo was methanol extracted and solvent fractionated in to five fractions (hexane, chloroform, ethylacetate, butanol and water). And each fractions were investigated inhibitory effects on platelet aggregation induced by various agonists using washed rabbit platelets in vitro.

• Journal of Ginseng Research
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• v.48 no.4
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• pp.428-434
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• 2024

Background: Platelet-leukocyte aggregates (PLAs) play important roles in cardiovascular disease and sepsis. Red ginseng extract (RGE) has been well-studied for its antiplatelet and anti-inflammatory activities. However, the potential inhibitory effects of RGE on PLA have not been investigated. Methods: Six-week-old ICR mice were given oral gavage of RGE for 7 days, followed by an intraperitoneal injection of 15 mg/kg of lipopolysaccharide. Mice were euthanized 24 h later, and blood samples were collected for further analysis. Flow cytometry was utilized to sort populations of PLAs and platelet-neutrophil aggregates (PNAs). By using confocal microscopy, PNAs were validated. Morphological changes in platelets and leukocytes were visualized with scanning electron microscopy. Expressions of tissue factor (TF) and platelet factor 4 (PF4) were investigated using enzyme-linked immunosorbent assay. Results: Populations of activated platelets, PLAs and PNAs, were significantly increased with LPS-induction. Treatment with 200 and 400 mg/kg of RGE decreased platelet activation. Moreover, the populations of PLAs and PNAs were reduced. PNAs were visible in the blood of septic mice, and this was attenuated by treatment with 400 mg/kg of RGE. Morphologically, sepsisinduced platelet activation and fibrin formation in the blood. This was reduced with RGE treatment. Sepsis-induced increase in the plasma levels of TF and PF4 was also reduced with RGE treatment. Conclusion: This study shows that RGE is a potential therapeutic that reduces the activation of platelets and targets PLA and PNA formation. Detailed inhibitory mechanisms of RGE should be studied.

• Archives of Plastic Surgery
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• v.33 no.6
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• pp.732-736
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• 2006

Purpose: The purpose of this pilot study was to investigate a potential of platelet concentrate obtained from blood bank(PCBB) in accelerating wound healing and to determine an effective treatment protocol by quantifying levels of platelet derived growth factor (PDGF)-BB in PCBB in vitro. Methods: The first study was designed to investigate quantity of PDGF-BB over stored time of the PCBB. The stored times for each PCBB were 1, 3, 5, 7, 9, 11 and 13 days. The second study was designed to determine efficacy of adding thrombin to stimulate release of PDGF-BB from the platelets of PCBB. The platelets were suspended and incubated in either with or without thrombin. On 30 minutes and days 1, 3, 5, 7 after incubation, the levels of PDGF-BB were measured. Results: PDGF-BB level showed a linear decrease over stored time of PCBB from the first day to the 13th day. Addition of thrombin increased PDGF-BB release from 30 minute through the 5th day. Conclusion: The results indicate that PCBB can provide sufficient amount of growth factors to stimulate wound healing and adding thrombin accelerate it.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.31 no.4
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• pp.367-377
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• 2021

Objectives: Taxi drivers are exposed to various hazards, such as long periods of sedentary work and traffic-related air pollutants. However, studies on the health effects among taxi drivers in South Korea are insufficient. Methods: To assess subclinical hematologic change related to cardiovascular disease among male taxi drivers, we analyzed data from the second Korean National Environmental Health Survey. Fifty-nine taxi drivers and 1,912 controls were included in the analysis. Propensity score matching was performed to adjust for age, body mass index, and urinary cotinine. A total of 295 subjects were matched with 59 taxi drivers. Leukocyte count, platelet count, hematocrit, triglyceride, total cholesterol, HDL cholesterol land total IgE of the taxi drivers were compared with the control groups. Results: Taxi drivers showed significantly elevated blood leukocytes and platelets. Serum total IgE was significantly reduced in taxi drivers. However, blood leukocytes, platelets, and serum total IgE were not significantly correlated with work period among taxi drivers. Conclusions: Regarding the change of the blood leukocyte count, platelet count, and serum total IgE, taxi driving has the possibility to be associated with peripheral inflammation, humoral immunity and cardiovascular risk.

• Journal of Radiation Protection and Research
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• v.34 no.3
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• pp.102-106
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• 2009

We exposed ICR mice to low-dose (0.2 Gy) and low-dose-rate (0.7 mGy/h) $\gamma$-radiation ($^{137}Cs$) in the Low-dose-rate Irradiation Facility at the Radiation Health Research Institute to evaluate systemic effects of low-dose radiation. We compared the body and organ weights, number of blood cells (white and red blood cells and platelets), levels of biochemical markers in serum, and frequency of micronuclei in polychromatic erythrocytes between low-dose irradiated and non-irradiated control mice. The ICR mice irradiated with total doses of 0.2 and 2 Gy showed no changes in body and organ weights, number of blood cells (white and red blood cells), or frequency of micronuclei in the polychromatic erythrocytes of peripheral blood. However, the number of platelets (P = 0.002) and the liver weight (P < 0.01) were significantly increased in mice exposed to 0.2 and 2 Gy, respectively. These results suggest that a low-dose-rate of 0.7 mGy/h does not induce systemic damage. This dose promotes hematopoiesis in the bone marrow microenvironment and the proliferation of liver cells. In the future, the molecular biological effects of lower doses and dose rates need to be evaluated.