• Journal of Periodontal and Implant Science
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• v.28 no.1
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• pp.187-191
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• 1998

Aplastic anemia is a disease characterized by general lack of bone marrow activity; It may affect not only the red blood cells but also the white blood cells and platelets, resulting in pancytopenia. Spontaneous gingival hemorrhage is present in some cases and it is related to the blood platelet deficiency. This case report presents the periodontal treatment of a patient with aplastic anemia. A 43-year-old female was referred for continuous gingival bleeding after periodontal treatment. Periodontal findings revealed generalized gingival imflammation, oozing of blood from gingival crevice, and it was diagnosed as adult periodontitis. Root planing and extraction of the upper left third molar with poor prognosis were put into operation after elevation of the platelet count with platelet transfusion. The extraction socket was sutured with 3-0 silk. Bleeding continued even after digital compression at the upper right second premolar, second molar, and left canine areas, which presented severe inflammation. Although platelets were transfused repeatedly, platelet count did not stay elevated since survival rate of the transfused platelets were low due to alloimmunization. Thrombin gauze packing was not effective. Bleeding ceased 3 days after treatment with transfusion of donor platelets. 20 days after the treatment, the gingiva was generally healthy except upper right second premolar and lateral incisor areas. The result of periodontal treatment was good, but bleeding control after treatment was troublesome. In the periodontal treatment of patient with aplastic anemia, elevation of the platelet count with platelet transfusion seems to be the best method for hemorrhage control.

• Journal of Veterinary Clinics
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• v.15 no.2
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• pp.352-357
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• 1998

Effects of chicken egg white derivatives (EWD and EF-203) on the changes of blood cells and the neutrophil phagocytic activity were examined in the rats. Rats were administered orally with either EWD (200 mg/kg) or EF-203 (200 mg/kg) for 3 days. Thereafter, the changes of blood cell values (RBC, WBC, platelets, PCV, differential count of neutrophils) and the phagocytic activity of neutrophils were evaluated for 7 days. The numbers of WBC and the differential count of neutrophils of rats administered with either EWD or EF-203 were significantly increased (p

• Proceedings of the Korean Society of Applied Pharmacology
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• 1996.11a
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• pp.75-84
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• 1996

Platelets from a patient with a mild inherited bleeding disorder and abnormal platelet aggregation and secretion show reduced generation of inositol 1,4,5-trisphosphate (IP$_3$), mobilization of intracellular Ca$\^$2+/, and phosphorylation of pleckstrin in response to several G protein mediated agonists, suggesting a possible defect at the level of phospholipase C (PLC) activation. A procedure was developed that allows quantitation of platelet PLC isozymes. After fractionation of platelet extracts by high-performance liquid chromatography, seven, out often known PLC isoforms were detected by immunoblot analysis. The amount of these isoforms in normal platelets decreased in the order PLC-${\gamma}$2 > PLC-${\beta}$2 > PLC-${\beta}$3 > PLC-${\beta}$l > PLC-${\gamma}$ > PLC-$\delta$1 > PLC-${\beta}$4. Compared with normal platelets, platelets from the patient contained approximately one-third the amount of PLC-${\beta}$2, whereas PLC-${\beta}$4 was increased threefold. These results suggest that the impaired platelet function in the patient in response to multiple G protein mediated agonists is attributable to a deficiency of PLC-${\beta}$2. They document for the first time a specific PLC isozyme deficiency in human platelets and provide an unique opportunity to understand the role of different PLC isozymes in normal platelet function.

• 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.

• Journal of Chest Surgery
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• v.26 no.2
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• pp.80-85
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• 1993

Synthetic and biosynthetic vascular grafts of small diameter have long been considered to be prone to thrombosis, ultimately leading to the complete graft occlusion. Endothelial cell seeding onto synthetic blood-contacting surfaces has been suggested to be an ideal means to solve this problem. This study described a culture method of bovine endothelial cells and evaluated blood-compatibility and seeding efficiency of cultured endothelial cells. Bovine pulmonary artery endothelial cells were harvested enzymatically and grown to confluence on polystyrene culture flask surfaces using established techniques. The identification of endothelial cells was made through the demonstration of expression of factor VIII R:Ag by immunofluorescent technique. To quantitate the effect of improvement in blood-compatibility of viable endothelial cells, endothelial monolayers were exposed to blood containing $\^$111/In-oxine labeled platelets. Viable endothelial monolayers retained less labeled platelets than control surfaces. The Indium-labeled endothelial cells were seeded onto three different blood-contacting surfaces of Dacron vascular graft immobilized in specially equipped wells and incubated for specific time intervals (t=15, 30, 60, 120 minutes). Longer incubation times showed improved cell adherence in collagen-coated and fibrin-coated Dacron vascular graft groups. However in untreated Dacron grafts, no direct relationship was observed between incubation time and endothelial cell seeding efficiency. This may be due to leakage of endothelial cells through porosity of Dacron grafts in this in-vitro experimental condition.

• 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.

• 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.

• Biotechnology and Bioprocess Engineering:BBE
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• v.10 no.6
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• pp.540-545
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• 2005

Poly(3-hydroxybutyrate-co-3-hydroxyvalerate), poly(3HB-co-3HV), copolyesters, with 3-hydroxyvalerate (3HV) contents ranging from 17 to 60 mol%, were produced by Alcaligenes sp. MT-16, and their biocompatibility evaluated by the growth of Chinese hamster ovary (CHO) cells and the adsorption of blood proteins and platelets onto their film surfaces. The number of CHO cells that adhered to and grew on these films was higher with increasing 3HV content. In contrast, the tendency for blood proteins and platelets to adhere to the copolyester surfaces significantly decreased with increasing 3HV content. Examination of the surface morphology using atomic force microscopy revealed that the surface roughness was an important factor in determining the biocompatibility of theses copolyesters. The results obtained in this study suggest that poly(3HB-co-3HV) copolyesters, with >30 mol% 3HV, may be useful in biocompatible biomedical applications.

• Bulletin of the Korean Chemical Society
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• v.35 no.9
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• pp.2625-2629
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• 2014

Platelets are anuclear discoid-shaped blood cells with key roles in human body. To understand the mechanisms of their activation process, it is required to have analytical imaging techniques capable of acquiring platelet images under fully hydrated conditions. Herein, for the first time, we demonstrate the capability of synchrotron-based transmission X-ray microscopy (TXM) to study platelets (resting and ADP activated) under hydrated and air-dried conditions. To confirm the biological imaging capability of TXM, fixed platelets were imaged and compared with whole mount electron microscopy (EM) images. TXM provided morphological information with sufficient spatial resolution with simple and quick sample preparation procedure. We also observed temporal changes during the platelet activation, which initially had a discoid shape (0 s), formed pseudopodia (30 s) and generated a network of fibrin (5 min). Our results clearly demonstrate the potential of TXM technique to study fully hydrated biological samples under in situ conditions.

• 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.