• 대한의생명과학회지
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• 제21권4호
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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.

• Biomolecules & Therapeutics
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• 제3권2호
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• pp.143-148
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• 1995

Recently, we reported that GS 389 has vasodilating action without cardiac inotropic action (Chang et al., Can. J. Physiol. Pharmacol. 72, 327-334, 1994). However the mechanism of action of GS 389 has not been thoroughly evaluated. In the present study, we performed functional study of GS 389 in rat trachealis, thoracic aorta, pig coronary artery by isometric tension and in human platelets by aggregation experiments. We also tested if GS 389 influences on $Ca^{2+}$movement and inositol phosphate metabolism. In rat trachealis, GS 389 concentration-dependently relaxed carbachol (0.1 $\mu$M)- and high $K^{+}$(65.4 mM)-induced contraction with p$IC_{50}$/ of 4.43$\pm$ 0.19 and 4.11$\pm$0.12, respectively. In $Ca^{2+}$-free media, GS 389 inhibited carbachol-induced phasic contraction. In rat thoracic aorta, GS 389 inhibited $^{45}$ Ca uptake due to norepinephrine and high $K^{+}$, indicating that GS 389 has direct inhibitory action of $Ca^{2+}$movement. Furthermore, GS 389 competitively inhibited U46619-induced contraction in rat thoracic aorta and pig coronary artery with K, values of 5.23$\pm$0.12 and 5.56$\pm$0.14, respectively, and inhibited U 46619-induced phosphatidylinositide (PI) turnover in rat aorta. GS 389 also concentration-dependently inhibited the human platelet aggregation against U 46619 with p$IC_{50}$/ 5.66$\pm$0.02. These results indicate that GS 389 has thromboxane $A_2$ antagonistic action in vascular and platelets as well as direct action on $Ca^{2+}$ movement, which may account, at least in part, for relaxing action of rat trachealis. trachealis.

• Steel and Composite Structures
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• 제35권1호
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• pp.111-127
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• 2020

The goal of this study is to fill this apparent gap in the area about investigating the effect of porosity distributions on vibrational behavior of FG sectorial plates resting on a two-parameter elastic foundation. The response of the elastic medium is formulated by the Winkler/Pasternak model. The internal pores and graphene platelets (GPLs) are distributed in the matrix either uniformly or non-uniformly according to three different patterns. The model is proposed with material parameters varying in the thickness of plate to achieve graded distributions in both porosity and nanofillers. The elastic modulus of the nanocomposite is obtained by using Halpin-Tsai micromechanics model. The annular sector plate is assumed to be simply supported in the radial edges while any arbitrary boundary conditions are applied to the other two circular edges including simply supported, clamped and free. The 2-D differential quadrature method as an efficient and accurate numerical approach is used to discretize the governing equations and to implement the boundary conditions. The convergence of the method is demonstrated and to validate the results, comparisons are made between the present results and those reported by well-known references for special cases treated before, have confirmed accuracy and efficiency of the present approach. It is observed that the maximum vibration frequency obtained in the case of symmetric porosity and GPL distribution, while the minimum vibration frequency is obtained using uniform porosity distribution. Results show that for better understanding of mechanical behavior of nanocomposite plates, it is crucial to consider porosities inside the material structure.

• Steel and Composite Structures
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• 제33권6호
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• pp.891-906
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• 2019

This study considers the instability behavior of sandwich plates considering magnetorheological (MR) fluid core and piezoelectric reinforced facesheets. As facesheets at the top and bottom of structure have piezoelectric properties they are subjected to 3D electric field therefore they can be used as actuator and sensor, respectively and in order to control the vibration responses and loss factor of the structure a proportional-derivative (PD) controller is applied. Furthermore, Halpin-Tsai model is used to determine the material properties of facesheets which are reinforced by graphene platelets (GPLs). Moreover, because the core has magnetic property, it is exposed to magnetic field. In addition, Kelvin-Voigt theory is applied to calculate the structural damping of the piezoelectric layers. In order to consider environmental forces applied to structure, the visco-Pasternak model is assumed. In order to consider the mechanical behavior of structure, sinusoidal shear deformation theory (SSDT) is assumed and Hamilton's principle according to piezoelasticity theory is employed to calculate motion equations and these equations are solved based on differential cubature method (DCM) to obtain the vibration and modal loss factor of the structure subsequently. The effect of different factors such as GPLs distribution, dimensions of structure, electro-magnetic field, damping of structure, viscoelastic environment and boundary conditions of the structure on the vibration and loss factor of the system are considered. In order to indicate the accuracy of the obtained results, the results are validated with other published work. It is concluded from results that exposing magnetic field to the MR fluid core has positive effect on the behavior of the system.

• Asian Pacific Journal of Cancer Prevention
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• 제16권9호
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• pp.3793-3797
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• 2015

Background: Chronic myeloid leukemia (CML) is a myeloproliferative disorder of pluripotent stem cells, caused by reciprocal translocation between the long arms of chromosomes 9 and 22, t(9;22)(q34;q11), known as the Philadelphia chromosome. Materials and Methods: A total of 51 CML patients were recruited in this study. Complete blood counts of all CML patients were performed to find out their total leukocytes, hemoglobin and platelets. FISH was performed for the detection of BCR-ABL fusion and cryptogenic tests using bone marrow samples were performed for the conformation of Ph (9;22)(q34;q11) and variant translocation mechanisms. Results: In cytogenetic analysis we observed that out of 51 CML patients 40 (88.9%) were Ph positive and 4 (8.88%) had Ph negative chromosomes. Mean values of WBC 134.5 $10^3/{\mu}l$, hemoglobin 10.44 mg/dl, and platelets 288.6 $10^3/{\mu}l$ were observed in this study. Conclusions: In this study, Ph positive translocation between chromosome (9:22)(q34;q11) were observed in 40 (88.9%) CML patients.

• Archives of Plastic Surgery
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• 제33권2호
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• pp.198-204
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• 2006

Many clinical trials have shown the effectiveness of the platelet releasate or the platelet gel on chronic wounds. However, the patient's own blood had to be aspirated and processed to make the platelet releasate or a platelet gel. The purpose of this study was to assess the effects of platelet concentrates from the blood bank for the treatment of diabetic foot ulcers. To obtain the basic data of the PDGF-BB content in platelet concentrates supplied from the blood bank, enzyme-linked immunosorbent assay quantification was performed. On average, 8.5 pg of the PDGF-BB was released per 1 million platelets. Sixteen patients with diabetic foot ulcers ranging from 1.0 to $18.0cm^2$(mean, $6.1cm^2$) in size were treated. The platelet concentrates was centrifuged and the precipitantte was mixed with 1 ml of fibrinogen. The platelets and fibrinogen mixture was dispersed on to the ulcer lesions. The liquid platelet and fibrinogen mixture was then sealed using 0.3-1.0 ml of thrombin and moisture dressing was performed. The procedure was repeated every one or two weeks until wound closure. Time required for complete healing ranged from 3 to 12 weeks after treatment (mean, 7.3 weeks). Patient satisfaction was also very positive. In this study, the use of platelet concentrates from the blood bank was found to be effective in treating diabetic foot ulcers.

• 한국식품위생안전성학회지
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• 제15권2호
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• pp.167-172
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• 2000

최근 동물성 식품 및 지방 섭취 증가로 인한 현대인의 식생활 변화로 혈소판 활성화가 직접적 원인인 뇌 .심혈관질환의 사망률이 증가되고, 성인병 예방과 치료의 대처방안으로 식품의 기능성에 대한 관심이 높아짐에 따라서 천연착색료이며 항균, 항암 작용이 있는 자근(Lithospermum erythrorhizon)으로부터 추출, 분리 . 정제한 분획물에서 혈소판 활성화 억제작용이 있는 생리활성물질을 분리 . 동정하였다 자근에서 methanol, n-hexane, ethyl acetate 등의 용매추출물과 methanol 추출물에 NaOH프 처리한 n-hexane 추출물에 대한 혈소판 응집 억제작용은 collagen의 응집작용에 대하여 n-hexane재추출물이, thrombin의 응집작용에 대하여 ethyl acetate추출물이 큰 억제작용을 보였고, 이러한 추출물에서 컬림 및 HPLC로 분리 .정제한 5개 물질의 화학구조를 IH과 13C-NMR 스펙트라 분석한 결과 shikonin, acethylshi onin, isobutylshikonin, $\alpha$-methyl-n-butylshikonin, $\beta$,$\beta$-dimethylacrylshikonin을 확인하였고, 혈소판 응집 억제작용은 $\beta$,$\beta$-dimethylacrylshi onin$\geq$$\alpha$-methyl-n-butylshikonin>isobutylshikonin>acetylshikonin>shikonin순으로 나타났다. 이상의 결과로부터 자근색소의 생리활성은 shikonin유도체이며 11번 탄소에 치환된 aliphatic 기의 탄소수가 많을수록 억제작용이 강하게 나타난다고 사료된다.

• Journal of Yeungnam Medical Science
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• 제28권1호
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• pp.99-104
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• 2011

Essential thrombocythemia (ET), a subcategory of chronic myeloproliferative disorder, is characterized by absolute thrombocytosis due to excessive clonal proliferation of platelets, hyperaggregability of platelets, and increased incidence of thrombosis and hemorrhage. We consider a diagnosis of ET when an unexplained and persistent thrombocytosis is observed. It is difficult to consider ET first when we meet a patient with esophageal varix bleeding or unusual multiple thromboses like mesenteric vein, splenic vein, and portal vein. This article reports a patient who presented initially with esophageal varix bleeding and unusual multiple thromboses, thereafter, she was diagnosed with ET after testing positive for the Janus Tyrosine Kinase 2 (JAK2) V617F mutation. In conclusion, in patients with varix bleeding and unusual multiple thromboses, myeloproliferative disorders like essential thrombocythemia should be considered as a potential cause and testing for the JAK2 mutation is warranted.

• The Korean Journal of Physiology and Pharmacology
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• 제3권2호
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• pp.199-205
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• 1999

Vibrio vulnificus cytolysin caused platelet cytolysis and increased intracellular calcium concentration $([Ca^{2+}]_i)$ of rat platelets in a concentration-dependent manner. In the presence of V. vulnificus cytolysin (3 HU/ml), lactate dehydrogenase (LDH) activity was increased from $1.3{\pm}0.4%$ of control to $64.3{\pm}3.4%$ in platelet suspension buffer. In $Ca^{2+}-free$ platelet suspension buffer, however, V. vulnificus cytolysin did not induce $[Ca^{2+}]_i$ increase and LDH release. Addition of EGTA (2 mM) to suspension buffer after the initial $Ca^{2+}$ influx reversed $[Ca^{2+}]_i$ to the control level. However, a $Ca^{2+}$ channel blocker verapamil $(20\;{\mu}M)$ or mefenamic acid $(20\;{\mu}M)$ did not inhibit V. vulnificus cytolysin-induced $[Ca^{2+}]_i$ increase and LDH release. Divalent cations such as $Co^{2+},\;Cd^{2+}\;or\;Mn^{2+}$ (2 mM each) also did not alter V. vulnificus cytolysin-induced $[Ca^{2+}]_i$ increase and LDH release. V. vulnificus cytolysin (3 HU/ml)-induced calcium influx was completely blocked by lanthanum (2 mM). Lanthanum (2 mM) also completely blocked V. vulnificus cytolysin (3 HU/ml)-induced LDH release. Osmotic protectants such as, raffinose, sucrose or PEG600 (50 mM each) did not inhibit the lytic activity of V. vulnificus cytolysin. In conclusion, lanthanum sensitive $Ca^{2+}$ influx plays a significant role in Vibrio vulnificus cytolysin-induced platelet cytolysis and thrombocytopenia in V. vulnificus infection.

• Archives of Plastic Surgery
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• 제34권3호
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• pp.285-290
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• 2007

Purpose: Many clinical trials have shown the effectiveness of platelet releasate on chronic wounds. However, a large volume of blood must be aspirated from a patient and a platelet separator is required. Here, we hypothesized that platelet concentrate obtained from a blood bank (PCBB) would be also effective at stimulating wound healing. The purpose of this study was to investigate the effectiveness of PCBB on accelerating healing of diabetic wounds in vivo. Methods: Round wounds of 5 mm diameter were made at four sites(two wounds on the left and two on the right side) on the backs of nine diabetic mice. Three hundred million platelets suspended in 0.05 ml fibrinogen were dispersed on each wound on left sides. Same amount of fibrinogen without platelets was dispersed on right side control wounds. Thereafter, 0.05 ml thrombin was applied to the each wound. Ten days after wound treatment, healed wounds were excised and the extent of wound healing in each group was compared. Results: Quantitative histologic analysis of epithelial gap distances revealed that PCBB treatment had greatly accelerated wound healing. Mean epithelial gap distances for PCBB treated and control wounds were $2.5{\times}0.6mm\;and\;3.6{\times}0.5mm$, respectively(p<0.05). Conclusion: Our results suggest that PCBB has potential to accelerate the healing of diabetic wounds.