• Journal of Ginseng Research
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• v.17 no.2
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• pp.131-134
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• 1993

Panaxadiol (PD) from Korean red ginseng C.A. Meyer did not control the concentration of cytosolic free $Ca^{2+}$ influxes by thrombin (5 $\mu$/ml). However, PD strongly inhibited the synthesis of thromboxane. $A_2$ (TX$A_2$) in the aggregation of human platelets induced by thrombin (5 $\mu$/ml). These rexults suggest that PD blocks the any Pathway transforming to TX$A_2$ from arachidonic acid (AA) which release out of plasma membrane phospholipids by $Ca^{2+}$-dependent phospholipase C or phospholipase $A_2$. It may be also concluded that PD has the antiplatelet function by inhibiting the synthesis of TX$A_2$, which known to be the potent stimulator of the aggregation of human platelet.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.14 no.5
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• pp.126-133
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• 2015

Recently, there has been demand for polymeric porous membranes in various fields, such as environmental engineering, pharmaceutics, tissue engineering, drug delivery, biology, and fuel cells. In this study, it is proposed that a polymer particle-based porous membrane can be fabricated using electrospraying and sintering processes. Electrospraying can fabricate polymeric particles with diameters ranging from several micrometers to tens of nanometers without the cumbersome particle aggregation problem. Additionally, the particles can be sintered through thermo-compression under the glass transition temperature. In this study, a polymethyl methacrylate particle-based porous membrane with an average pore size of less than 500 nm is fabricated using the proposed method.

• Journal of Microbiology and Biotechnology
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• v.7 no.6
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• pp.378-385
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• 1997

Cation motive ATPases on cell membranes of Helicobacter pylori were investigated using everted membrane vesicles. Latent ATPases could be ascertained from aggregated vesicle using N, N-dimethylformamide (DMF) and Triton X-100. By contrast, ultrasonication or chloroform treatments caused membranes to be disrupted, resulting in an alteration of sensitivities against azide or vanadate. Considerable amounts of vanadate-sensitive enzymes were identified from vesicle micelles, prepared by the dilution method. These were activated in the presence of either $Ni^{2+}\;or\;NH_4^+$. From studies employing H. pylori intact cell systems, we found that ATPase expression of this bacterium was markedly dependent upon air composition. It was interesting that cellular expression of $Ni^{2+}$- or $NH_4^{+}$-motive ATPases was significantly affected by extracellular pH, suggesting that these unique enzymes may physiologically be involved in cellular $Ni^2$ import and $NH_4^+$ export, respectively.

• Journal of Chest Surgery
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• v.25 no.5
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• pp.526-532
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• 1992

The effect of cardiopulmonary bypass on platelet count and function was studied in 20 patients who underwent cardiac operation from April 1991 to August 1991 at the Department of thoracic and Cardiovascular Surgery, School of Medicine, Keimyung University. Ten patients were perfused with a bubble oxygenator, 10 with a membrane oxygenator. During and after bypass, platelet counts decreased in both groups and significantly reduced in those perfused with a bubble oxygenator. All 20 patients studied for platelet functions had an abnormal postoperative aggregation response to collagen and epinephrine, but no significant difference in both groups. One hour after bypass, bleeding times increased in both groups but did not differ significantly between groups. Postoperative 24 hour blood losses were significantly higher in patients perfused with a membrane oxygenator. Platelet damage and postoperative blood loss are less severe after cardiopulmonary bypass performed with a membrane oxygenator than with a bubble oxygenator.

• Journal of Microbiology and Biotechnology
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• v.9 no.3
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• pp.276-281
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• 1999

In order to determine the functional region of the antifungal protein (AFP) isolated from Aspergillus giganteus responsible for growth inhibitory activity and the promotion of phospholipid vesicle aggregation, overlapping peptides covering the complete sequence of AFP were synthesized. The antibiotic activity against bacterial, fungal, and tumor cells, and the vesicle-aggregation activity of the synthetic peptides were investigated. The AFP functional sequence responsible for antibiotic and vesicle-aggregation activity was determined to be located within the region between AFP residues 19 to 32. AFP (19-32) exhibited an a-helical conformation in a cell membrane-like environment. AFP (19-32) displayed potent antibiotic activity against bacterial, fungal, and tumor cells without peptide toxicity as indicated by hemolysis. Accordingly, AFP (19-32) could be used as a good model for the design of effective antibiotic agents with powerful antibiotic activity yet without any cytotoxic effects against the host organism.

• Journal of Physiology & Pathology in Korean Medicine
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• v.17 no.2
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• pp.560-567
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• 2003

Antimetastatic effects of Agaricus mixed prescription (AMP) were studied in the respect of blood-borne metastasis. For this aim, cytotoxicity against various cancer cells and normal cells, Chicken Chorioallantoic membrane (CAM) assay, cancer cell adhesion assay, platelet aggregation assay, pulmonary colonization, life span of S-180 implanted mice, and cytokine release assay were evaluated, respectively. The results were summarized as follows; AMP did not exert any cytotoxicity against all cell lines with IC50 of 25mg/ml on B16BL6. AMP disrupted formation of CAM at 1mg/ml. AMP was suppressive in adhesion assay of B16BL6. AMP also inhibited tumor induced platelet aggregation. In pulmonary colonization assay by B16BL6, the number of colonies in the lungs was significantly decreased in sample group than in control group. In animal study with S-180, the life span of AMP treated group was extended than that of control group. IL-12 was effectively increased in AMP treated group in cytokine release assay. Taken together, AMP can be possibly applied to cancer or metastasis.

• Biomedical Science Letters
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• v.29 no.1
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• pp.41-47
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• 2023

Discovery of new substance that can regulate platelet aggregation or suppress aggregation will aid in the prevention and treatment of cardiovascular diseases. Artesunate is a compound from plant roots of Artemisia or Scopolia, and its effects have shown to be promising in areas of anticancer and Alzheimer's disease. However, the role and mechanisms by which artesunate affects the aggregation of platelets, and the formation of a thrombus are currently not understood. This study examined the ways artesunate affects platelets activation and thrombus formation induced by collagen. As a result, cAMP and cGMP production were increased significantly by artesunate relative to the doses, as well as phosphorylated VASP and IP₃R, substrates to cAMP-dependent kinase and cGMP-dependent kinase, in a significant manner. The Ca²⁺ normally mobilized from the dense tubular system was inhibited due to IP₃R, phosphorylation from artesunate, and phosphorylated VASP aided in inhibiting platelet activity via αIIb/β₃ platelet membrane inactivation and inhibiting fibrinogen binding. Finally, artesunate inhibited thrombin-induced thrombus formation. Therefore, we suggest that artesunate has importance with cardiovascular diseases stemming from the abnormal platelets activation and thrombus formation by acting as an effective prophylactic and therapeutic agent.

• Membrane Journal
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• v.1 no.1
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• pp.55-64
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• 1991

The ultrathin membranes of cellulose acetate and polyvinyl chloride were prepared by the method of watercasting. The spreading ability of polymer solutions on water doereased with increasing the surface tention and the viscosity of polymer solutions, and the temperature of water surface, respectively. The aggregation states of water-casting membranes were dense and dense with increasing the concentration of polymer solutions and the temperature of water surface. The surface structure of the air sides showed more dense than that of the water sides. In the case of the 3 wt% cellulose acetate/acetone system, the thickness of the membrane was about $0.1{\mu}.$.

• Journal of Chest Surgery
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• v.21 no.1
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• pp.26-35
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• 1988

The effect of cardiopulmonary bypass on platelet count, platelet function, and bleeding time was studied in 60 patients. Platelet count was significantly reduced during and after cardiopulmonary bypass. Platelet function also had a reduced aggregation response to adenosine diphosphate. Bleeding time was prolonged to over 30 minutes during cardiopulmonary bypass and not returned to normal level until postbypass 1 hour. The amount of postoperative bleeding was proportional to the degree of decrease in platelet count and function, degree of decrease in platelet count and function. There was no significant correlation between duration of cardiopulmonary bypass and platelet count, platelet function, bleeding time, or amount of postoperative bleeding. Patients with cyanotic congenital heart disease showed a larger amount of postoperative bleeding than patients with acyanotic congenital heart disease [P<0.01], and this difference was due to the fact that platelet function was more significantly affected by cardiopulmonary bypass in cyanotic group. Patients using membrane oxygenator showed a less amount of postoperative bleeding than patients using bubble oxygenator [p<0.005] reflecting better preservation of platelet count and function by membrane oxygenator.

• Proceedings of the Membrane Society of Korea Conference
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• 1995.04a
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• pp.16-20
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• 1995

The spontaneous self-organization of amphiphilic molecules into complex aggregates was undoubtedly an important factor in the emergence of life on earth. We study the parameters governing the self-organization of a simple amphiphilic model system using electron cryomicroscopy of ice-embedded specimens in combination with extensive data analysis. Different stable helices can be generated reproducibly by changing the parameters controlling the molecular aggregation process. The repeating units of the helical aggregates in the micrographs can be found by multivariate statistical image analysis techniques, and these two-dimensional projection images suffice for calculating the three-dimensional density distribution of the fibers. We present a typical structure consisting of a narrow stack of compartmented bilayers twisted into a left-handed helix. Our new techniques directly elucidate the three-dimensional structure of helical assemblies, and can complement or replace diffraction-based approaches.