• Maxillofacial Plastic and Reconstructive Surgery
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• v.27 no.1
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• pp.24-31
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• 2005

Recently, Platelet rich plasma(PRP) is commonly used because it is now well known that platelets have many functions beyond that of simple hemostasis in aspect of containing autogenous source of several growth factors. It could be responsible for increasing cell mitosis, increasing collagen production, recruiting other cells to the site of injury, initiating vascular ingrowth, and inducing cell differentiation, enhancing bone formation capacity and easily handling to clinician. However, in spite of these clinical advantages, still the theory behind the use of PRP is compelling. This study was to determine preparation techniques used to increase the concentration of platelets and growth factors are all crucial steps in early wound healing of bone graft which may lead to a more rapid and denser bone regenerate. 200 volunteers were sampled and PRP were prepared according to each evaluation item in this study. Higher concentration of platelets have been gained in double centrifugation. 2000 and 2500 rpm showed proper concentration of platelets at first centrifugation and 5000 rpm in second. Timing for 2 minutes was showed good concentration of platelets in high and low centrifugation speed. It was better concentration of platelets in 20 or 30 ml volume during centrifugation. In histomorphologic findings, degrnulated and high concentraion of platelets were found in low centrifugation speed.

• Archives of Plastic Surgery
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• v.36 no.1
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• pp.19-23
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• 2009

Purpose: Platelet transplantation is a novel therapeutic strategy for acceleration of wound healing. When applying platelets, efficacy of adding thrombin to stimulate growth factor release from platelets has already been proved. However, no quantitative data of the thrombin treatment has been reported. The purpose of this study was to determine the optimal thrombin concentration to maximize growth factor release of platelets. In particular, this study was designed to quantify levels of platelet derived growth factor(PDGF)-BB, which is a major growth factor contained in the platelets, in vitro. Methods: Fresh platelets were obtained from a blood bank. They were suspended in DMEM/F - 12 and incubated with thrombin of various concentrations. The concentrations of thrombin tested were 0, 6.25, 12.5, 25, 50, 100, 200, and 400 IU/ml. After 30 minutes, 1, 3, 5, and 7 days, the levels of PDGF - BB were measured using enzyme linked immunosorbent assay. Platelets from four donors were included in this study. Each sample was tested in triplicate and the mean value was used as a data for each sample. Results: The addition of thrombin increased the level of PDGF - BB. Increases in storage time of platelets resulted in decreased levels of PDGF - BB. Higher levels of PDGF were detected in consort with increased thrombin concentrations. However, there was no significant difference between samples of 200 and 400 IU/ml concentrations. Conclusion: The results indicate that adding thrombin accelerates the release of growth factors from platelets and the optimal thrombin concentration to maximize this function is 200 IU/ml.

• Toxicological Research
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• v.20 no.2
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• pp.137-142
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• 2004

We investigated the effects of plant vinegar on platelets and blood coagulation system. Plant vinegar inhibited in vitro platelet aggregation in a concentration dependent manner, when platelets were activated by thrombin and collagen. In addition, plant vinegar showed inhibitory effects on the serotonin secretion induced by thrombin in a concentration dependent manner. However, treatment with plant vinegar to platelets did not induce any cytotoxicity, as determined by the release of lactate dehydrogenase. Plant vinegar did not change the coagulation parameters such as activated partial thromboplastin time (aPTT) and prothrombin time (PT) using rat citrated plasma. In vivo study revealed that, treatment with plant vinegar prolonged the bleeding time from mouse tail. All these results suggest that plant vinegar might improve blood hemostasis mediated via anti platelet activities.

• Biomedical Science Letters
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• v.23 no.3
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• pp.208-214
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• 2017

To investigate the effects of strenuous physical exercise on commonly used hematological markers in subjects the intensive long running. Blood samples were obtained from nineteen participants in a 622 km ultra-marathon race before, 300 km and immediately after completion of the 622 km ultra-marathon. Samples were analyzed for total white cell count (WBC) and differential, total red cell count (RBC), hemoglobin, hematocrit, mean corpuscular volume (MCV), mean corpuscular hemoglobin (MCH), mean corpuscular hemoglobin concentration (MCHC), red cell distribution width (RDW), platelets, mean platelets volume (MPV), platelets distribution width (PDW). Significant increases were found in WBC, neutrophil and platelets at 622 km compared to the pre-race. RBC, hemoglobin and hematocrit decreased statistically significantly the race at 300 km and 622 km compared to pre-race. A wide range of hematological perturbations occur during 622 km ultra-marathon running but it was physiological changes within a reference range. The 622 km ultra-marathon is less likely to cause clinically significant hematologic changes in athletes.

• YAKHAK HOEJI
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• v.41 no.6
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• pp.749-755
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• 1997

It has been reported that dose-dependent $Ca^{2+}$ increase by menadione in platelets could be measured by fluorescent dye, quin-2. The problems will be described here rel ating to measuring $Ca^{2+}$ in menadione-exposed platelets using fura-2 and fluo-3, widely used fluorescent indicators. Additions of menadione to fura-2 loaded platelets and their lysates resulted in marked reduction in fluorescence intensity at both 340nm ($Ca^{2+}$-unbound form) 380nm ($Ca^{2+}$-undbound form) excitation wavelengths. Fura-2 excitation spectra were overlapped with UV-visible absorption spectra of menadione, suggesting that light absorption by menadione itself could quench fluorescence generated by fura-2. Next approach was to use fluo-3 which has the higher wavelength (490nm) of excitation. Previous work demonstrated that treatment with probenecid to platelets was required to prevent fluo-3 dye leakage. However, probenecid itself was proven to be inadequate to measure the concentration of intracellular $Ca^{2+}$; by reducing menadione-induced cytotoxicity in platelets. Our results suggest that it is not feasible to measure $Ca^{2+}$ in platelets by using fura-2 and fluo-3 in the presence of probenecid, and cautions should be taken to measure changes of intracellular $Ca^{2+}$ levels by fluorescent dyes following chemical exposure.

• Archives of Pharmacal Research
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• v.21 no.6
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• pp.774-778
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• 1998

Brazilin [7,11b-dihydrobenz[b]indeno[1,2-d]pyran-3,6a,9,10(6H)-tetrol] inhibited thrombin-, collagen- and ADP-induced aggregation of washed rat platelets. T hrombin- and collagen-induced ATP release were also inhibited by brazilin in a concentration-dependent manner. Brazilin inhibited the formation of platelet thromboxane $A_2$ caused by thrombin, whereas it had no effect on the prostaglandin $D_2$ formation. Brazilin inhibited $^3H$-arachidonic acid liberation from membrane phospholipids of thrombin-stimulated platelets. Brazilin inhibited the rise of intracellular free calcium caused by thrombin. These results indicate that the inhibition of phospholipase ($PLA_2$) activity and [$[Ca^{2+}]_1$ elevation might be at least a part of antiplatelet mechanism of brazilin.

• Journal of Animal Science and Technology
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• v.60 no.8
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• pp.20.1-20.4
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• 2018

Platelet rich plasma (PRP) is popularly used in the horse industry to enhance regeneration of tissue injury that has limitation of blood supply. This study aimed to compare the methods for platelet rich plasma preparation since they has not been established yet. Blood was collected from six horses and platelets were concentrated by three different methods (2-step centrifugation, separated centrifugation and separated centrifugation using histopaque). Concentrated blood was analyzed using Advia hematology systems. In the result, separated centrifugation with histopaque showed the significantly lower number of red blood cells than other groups. The 2-step centrifugation showed the significantly higher number of white blood cells than other groups, while it contained the highest concentration of red blood cells among three groups. In the 2-step centrifugation, separated centrifugation and separated centrifugation with histopaque, platelets were concentrated 4.5, 5.3 and 5.6 times, respectively. And no significant difference of the platelet concentration between the three groups was found. This study demonstrated that separated centrifugation using histopaque was the best method for platelet rich plasma preparation because of the proper amount of platelets and the separation of red blood cells from platelet rich plasma.

• Journal of Ginseng Research
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• v.21 no.2
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• pp.132-140
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• 1997

The effects of ginsenosides purified from red ginseng on platelet aggregation were investigated. Preincubation of washed platelets from rats with either ginsenoside Rg3, ginsenosides non-polar fraction (G-NPF), ginsenoside Rg1(Rg1) or ginsenosides polar fraction(G-PF) reduced the plytelet aggrelation induced by collagen in a dose-dependent manner, whereas ginsenoside Rg2 failed to inhibit the aggregation. Their IC50 values of Rg3, G-NPF, Rgl, and G-PF were 8.7$\pm$1.0, 150.3$\pm$0.1, 369.9$\pm$ 1.0, 606.211.3 $\mu\textrm{g}$/ml, respectively. Aggrelation induced by thrombin was also inhibited by Rg3 and G-NPF with IC50 being 5.2$\pm$ 1.1 and 66.5$\pm$0.8 $\mu\textrm{g}$/ml, respectively. The alterations of Intracellular Ca2+ concentration in platelets were monitored using fura-2 as a fluorescent Ca2+ indicator. Both Ca2+ release from internal stores and Ca2+ influx into cytosol were suppressed by Rg3. Rg3 also inhibited granular release of ATP and TXA2 formation induced by thrombin in a dose-dependent manner in the washed platelets. Rg3 also inhibited Aggregation and ATP release from human platelets induced by collagen to a similar extent as were observed in rat platelets. In conclusion, Rg3 is a Potent anti-aggregating component in ginsenosides and may exert its anti-aggrega1ing activity by decreasing TXAa formation and granular secretion in platelets, most likely by inhibiting Ca2+ influx and Ca2+ mobilization from intracellular stores. Thus ginseng may contribute to the prevention and treatment of thrombosis.

• Journal of Nutrition and Health
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• v.25 no.5
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• pp.339-350
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• 1992

This study was performed to investigate the effect on polyunsaturate fatty acid diets and feeding periods on the antithrombosis. the hematological changes in the blood and fatty acid compositions of platelets in rats. Each group of rats was fed a diet containing 20%(W/W) corn oil beef tallow sardine oil and the general stock diet for 10, 20. 40 and 80 days. Rats fed sardine oil diet showed significantly longer bleeding time than any other diet groups after 20 days feeding The whole blood clotting time of sardine oil group fed for 80 days was increased significantly. The number of platelet and the concentration of hemoglobin showed no significant difference among all groups. The number of white blood cell was decreased continously in sardine oil group after 10 days feeding. The level of malondialdehyde generation during thrombin-induced aggregation of platelets was decreased continously in sardine oil grou after 20 days feeding. With regard to the composition of platelet fatty acid the ratio of eicosapentaenoic acid(EPA 20: 5 $\omega$-3) to arachidonic acid(AA 20:4 $\omega$-6) was increased in sardine oil group but decreased in corn oil groups and beef tallow groups with days. In conclusion the rats fed sardine oil diet for more than 20 days showed the fact that EPA induced the antithrombosis. the changes in number of white blood cell and the fatty acid composition of platelets.

• YAKHAK HOEJI
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• v.56 no.6
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• pp.382-389
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• 2012

Effects of citrate-capped silver nanoparticles (AgNPs) on the blood coagulation and platelet aggregation were investigated using whole blood, platelet rich plasma (PRP) and washed platelet obtained from SD male rats. To confirm the stability of AgNPs in the test, size distribution of the nanoparticles was measured in the vehicles including distilled water, serum, and platelet buffers. The average size of AgNPs was 20 nm in the vehicles, which means that the stability was maintained during the whole experimental period. When blood coagulation was monitored by using whole blood impedance aggregometer, coagulation was not observed at the concentration of 1, 10 and 50 ppm. Platelets in plasma or in buffer were not aggregated by AgNPs at the concentration of 1, 2 and 4 ppm, respectively. The test concentration of AgNPs could not be increased because the dark color of the nanoparticles impeded the transmission of light, which is an indicator of aggregation. Although the blood or platelets were pre-activated by collagen, thrombin, or ADP with sub-threshold level, aggregation was not observed at the test concentration. Microscopic observation also supported the result obtained by the aggregometer.