• Title/Summary/Keyword: COX

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New screening method for anti-inflammatory agent (Cyclooxygenase 억제제 검색을 통한 항염증제 개발 연구)

  • Lee, Su-Hwan;Jeong, Seong-Won;Lee, U-Yeong
    • Journal of the Society of Cosmetic Scientists of Korea
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    • v.20 no.1
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    • pp.25-36
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    • 1994
  • It is weal known that bacterial lipopolysaccharide (LPS) stimulates prostaglandin synthesis in various experimental system via enhancing the expression of cylooxygenase-2 (COX-2). This study was designed to characterize U)5-induced prostaglandin synthesis in mouse peritoneal macrophages LPS-stimulated prostaglandin synthesis in macrophages with short term exposure was not so much prominent, but there was a burst in prostaglandin synthesis 8 hours after the LPS treatment and this u·as accompanied with the increase of cyclooxygenase activity, Dexamethasone markedly inhibited prostaglandin synthesis in this system. Metabolic label ins data supported above observations and thus, it could be concluded that LPS induces the do novo synthesis of COX-2 by which it stimulates the prostaglandin synthesis in mouse peritoneal macrophages, These data suggested that this experimental model system could be used for the screening procedure of COX-2 selective inhibitors. Ketoprofen, a non steroidal anti inflammatory agent, appeared to inhibit COX-1 relatively more selectively than COX-2.

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Inhibitory Effects of Epigallocatechin-3-Gallate on Microsomal Cyclooxygenase-1 Activity in Platelets

  • Lee, Dong-Ha;Kim, Yun-Jung;Kim, Hyun-Hong;Cho, Hyun-Jeong;Ryu, Jin-Hyeob;Rhee, Man Hee;Park, Hwa-Jin
    • Biomolecules & Therapeutics
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    • v.21 no.1
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    • pp.54-59
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    • 2013
  • In this study, we investigated the effect of (-)-epigallocatechin-3-gallate (EGCG), a major component of green tea catechins from green tea leaves, on activities of cyclooxygenase (COX)-1 and thromboxane synthase (TXAS), thromboxane $A_2$ ($TXA_2$) production associated microsomal enzymes. EGCG inhibited COX-1 activity to 96.9%, and TXAS activity to 20% in platelet microsomal fraction having cytochrome c reductase (an endoplasmic reticulum marker enzyme) activity and expressing COX-1 (70 kDa) and TXAS (58 kDa) proteins. The inhibitory ratio of COX-1 to TXAS by EGCG was 4.8. These results mean that EGCG has a stronger selectivity in COX-1 inhibition than TXAS inhibition. In special, a nonsteroid anti-inflammatory drug aspirin, a COX-1 inhibitor, inhibited COX-1 activity by 11.3% at the same concentration ($50{\mu}M$) as EGCG that inhibited COX-1 activity to 96.9% as compared with that of control. This suggests that EGCG has a stronger effect than that of aspirin on inhibition of COX-1 activity. Accordingly, we demonstrate that EGCG might be used as a crucial tool for a strong negative regulator of COX-1/$TXA_2$ signaling pathway to inhibit thrombotic disease-associated platelet aggregation.

Evaluation of Cytotoxicity Effects of Chalcone Epoxide Analogues as a Selective COX-II Inhibitor in the Human Liver Carcinoma Cell Line

  • Makhdoumi, Pouran;Zarghi, Afshin;Daraei, Bahram;Karimi, Gholamreza
    • Journal of Pharmacopuncture
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    • v.20 no.3
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    • pp.207-212
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    • 2017
  • Objectives: Study of the mechanisms involved in cancer progression suggests that cyclooxygenase enzymes play an important role in the induction of inflammation, tumor formation, and metastasis of cancer cells. Thus, cyclooxygenase enzymes could be considered for cancer chemotherapy. Among these enzymes, cyclooxygenase 2 (COX-2) is associated with liver carcinogenesis. Various COX-2 inhibitors cause growth inhibition of human hepatocellular carcinoma cells, but many of them act in the COX-2 independent mechanism. Thus, the introduction of selective COX-2 inhibitors is necessary to achieve a clear result. The present study was aimed to determine the growth-inhibitory effects of new analogues of chalcone epoxide as selective COX-2 inhibitors on the human hepatocellular carcinoma (HepG2) cell line. Methods: Estimation of both cell growth and the amount of prostaglandin E2 (PGE2) production were used to study the effect of selective COX-2 inhibitors on the hepatocellular carcinoma cell. Cell growth determination has done by MTT assay in 24 h, 48 h and 72 h, and PGE2 production has estimated by using ELYSA kit in 48 h and 72 h. Results: The results showed growth inhibition of the HepG2 cell line in a concentration and time-dependent manner, as well as a reduction in the formation of PGE2 as a product of COX-2 activity. Among the compounds those analogues with methoxy and hydrogen group showed more inhibitory effect than others. Conclusion: The current in-vitro study indicates that the observed significant growth-inhibitory effect of chalcone-epoxide analogues on the HepG2 cell line may involve COX-dependent mechanisms and the PGE2 pathway parallel to the effect of celecoxib. It can be said that these analogues might be efficient compounds in chemotherapy of COX-2 dependent carcinoma specially preventing and treatment of hepatocellular carcinomas.

Prognostication by Cluster Analysis of COX-2, MMP-9 and P53 Expression and by Clinico-pathologic Correlation Analysis in Non-small Cell Lung Cancer (비소세포폐암에서 COX-2,MMP-9와 돌연변이형 p53 의 발현이 생존에 대한 예후 분석)

  • Shin, Jong Wook;Choi, Jae Ho;Park, In Won;Yoo, Jae Hyung
    • Tuberculosis and Respiratory Diseases
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    • v.63 no.1
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    • pp.31-41
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    • 2007
  • Background: In pathogenesis and prognosis of lung cancer, significance of enormous types of genetic expression were very compounding and undetermined. We performed this study to search association between clinical characteristics and expression of COX-2, MMP-9 and p53 in non-small cell lung cancer. Methods: Ninety-one patients with adenocarcinoma or squamous cell carcinoma were enrolled. We had searched clinical data retrospectively and performed immunohistochemical staining for COX-2, MMP-9 and p53. We had analyzed significance of these three genes in clinical features and prognosis for survival. Results: 1) In squamous cell carcinoma, male was predominant and was significantly correlated with smoking. 2) Major prognostic determinants for overall survival were curative resection. 3) Expression of COX-2 was more frequent in adenocarcinoma than in squamous cell carcinoma. 4) Negative staining of COX-2, MMP-9 and p53 was more frequent in squamous cell carcinoma than adenocarcinoma. 5) Survival duration was longer in the group with positive expression of p53 and negative for COX-2 and MMP-9 (median duration of survival = 165.6 weeks) than groups with the other expressional patterns. 6) Significant correlation was found between expression of MMP-9 and COX-2. In squamous cell carcinoma, expression of MMP-9, COX-2 and mutant p53 were mutually correlated. 7) COX-2 expression was significant prognostic factor for survival in resected cancer group. In unresected inoperable non-small cell lung cancer group, MMP-9 was statistically significant prognostic factor for overall survival. Conclusion: COX-2 and MMP-9 might have some roles for progression or prognosis in some selected patients with non-small cell lung cancer. COX-2 and MMP-9 may have some roles for disease progression or prognosis in selected patients with NSCLC.

Cyclooxygenase-2 Expression in Benign and Malignant Chondroid Tumors (양성 및 악성 연골 종양의 Cyclooxygenase-2 발현)

  • Park, Hye-Rim;Min, Kwang-Seon;Park, Yong-Koo
    • The Journal of the Korean bone and joint tumor society
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    • v.13 no.2
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    • pp.105-112
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    • 2007
  • Purpose: Recent studies have shown increased levels of cyclooxygenase-2 (COX-2) in various human malignancies to include various bone and soft tissue tumors. However, little is known with regard to COX-2 expression patterns in chondroid tumors. Materials and Methods: Immunohistochemistry assays were performed for COX-2 in enchondromas (n=10), chondroblastomas (n=11), chondromyxoid fibromas (n=5), conventional chondrosarcomas (n=17), clear cell chondrosarcomas (n=7), and mesenchymal chondrosarcomas (n=6). Results: Among the benign chondroid tumors, chondroblastomas revealed characteristic strong positivity in 6 of 11 cases(54.5%). All enchondromas and chondromyxoid fibromas were negative except in one case. In conventional chondrosarcomas, three cases(17.6%) were strongly reactive with COX-2 and all positive cases represented grade III chondrosarcomas. Clear cell chondrosarcomas were found to be focally positive in two cases(28.5%), while all mesenchymal chondrosarcomas were negative. Conclusions: These findings suggest that COX-2 overexpression in conventional chondrosarcoma may represent an advanced histologic grade. Interestingly, expression of COX-2 in chondroblastomas could be an important factor for inducing peritumoral inflammatory changes in these specific tumors.

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A Phylogenetic Study of Staurastrum Complex (Chlorophyta) Inferred from coxIII Sequence Analysis (coxIII 유전자 염기서열 분석에 의한 팔장고말 COMPLEX(녹조식물문)의 계통 연구)

  • Moon, Byeong-Ryeol;Lee, Ok-Min
    • ALGAE
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    • v.19 no.3
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    • pp.153-160
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    • 2004
  • The intergeneric relationship of Staurastrum complex including genus Arthrodesmus and Xanthidium was studied on the basis of mitochondrial coxⅢ sequence variation. Teiling's suggestion that Staurodesmus was an independent genus apart from genus Staurastrum, Arthrodesmus and Cosmarium was also reevaluated. The phylogeny inferred from coxⅢ gene was not consistent with morphological characteristics of Staurastrum complex. Genus Staurastrum was closely related to genus Xanthidium in the phylogenetic analysis of coxⅢ, but distant to genus Staurodesmus. The taxonomic treatment of genus Staurodesmus as an independent entity could not be determined, because Staurodesmus did not firm a monophyletic Glade. Therefore, genus Staurodesmus could not be treated as an independent genus as Prescott et al. (1982) claimed.

Cyclooxygenase-2 as a Molecular Target for Cancer Chemopreventive Agents

  • Surh, Young-Joon
    • Toxicological Research
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    • v.17
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    • pp.89-96
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    • 2001
  • Recently, considerable attention has been focused on the role of cyclooxygenase-2 (COX-2) in the carcinogenesis as well as in inflammation. Improperly overexpressed COX-2 has been observed in many types of human cancers and transformed cells in culture. Thus, it is conceivable that targeted inhibition of abnormally or improperly up-regulated COX-2 provides one of the most effective and promising strategies for cancer prevention. A ubiquitous eukaryotic transcription factor, NF-kB is considered to be involved in regulation of COX-2 expression. Furthermore, extracellular-regulated protein kinase and p38 mitogen-activated protein (MAP) kinase appear to be key elements of the intracellular signaling cascades involved in NF-kB activation in response to a wide array of external stimuli. Certain chemopreventive phytochemicals suppress activation of NF-kB by blocking one or more of the MAP kinases, which may contribute to their inhibitory effects on COX-2 induction. One of the plausible mechanisms by which chemopreventive phytochemicals inhibit NF-kB activation involves suppression of degradation of the inhibitory unit I kB, which hampers subsequent translocation of p65, the functionally active subunit of NF-kB.

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Flood Frequency Analysis by the Box-Cox Transformation

  • 이순혁;조성갑;박명곤
    • Magazine of the Korean Society of Agricultural Engineers
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    • v.32 no.E
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    • pp.20-32
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    • 1990
  • Abstract This study was conducted to pursue the normalization of frequency distribution by making an approach to the coefficient of skewness to nearly zero through the Box-Cox transformation, to get probable flood flows can be calculated by means of the transformation equation which has been derivated by Box-Cox transformation in the annual maximum series of the applied watersheds. It has been concluded that Box-Cox transfromation is proved to be more efficient than logarithmic, square root and SMEMAX transformation which is based on the trigonometric solution of a right triangle whose three verteces repesent the smallest, median and largest observed values of a population in making the coefficient of skewness nearer to zero. Consequently it is shown that probable flood flows according to the return period based on Box-Cox transformation are closer to the observed data as compared to other methods including SMEMAX transformation and fitted probability distributions such as the three parameter lognormal and the type I extremal distribution for the applied watersheds.

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The Cox-Maze Procedure for Atrial Fibrillation not Associated with Mitral Valve Disease -Report of three cases- (승모판막질환을 동반하지 않은 심방세동에서의 Cox-Maze 술식 -3례 보고-)

  • 강창현;김기봉
    • Journal of Chest Surgery
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    • v.31 no.12
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    • pp.1230-1233
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    • 1998
  • The Cox-Maze procedure was developed as a cure for atrial fibrillation. The recovery rate of both atrial contractility is reported low in the atrial fibrillation associated with mitral valvular heart disease than that of loan atrial fibrillation. We performed the Cox-Maze procedure (Maze III) in three cases who suffered from non-mitral heart diseases associated with atrial fibrillation: A ruptured sinus of Valsalva aneurysm, a ventricular septal defect, and an aortic stenoinsufficiency. The Cox-Maze procedure was performed concomitantly with correction of the underlying heart disease. Conversion to sinus rhythm was achieved in all three patients, and both right and left atrial mechanical activities could be identified echocardiographically after three postoperative months.

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A Phylogenetic Significance of Several Species from Genus Cosmarium (Chlorophyta) of Korea Based on Mitochondrial coxIII Gene Sequences (미토콘드리아 coxIII 유전자 염기서열에 의한 수 종의 한국산 장고말속 식물(녹조식물문)의 계통분류학적 유의성)

  • Mun, Byeong-Ryeol;Lee, Ok-Min
    • ALGAE
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    • v.18 no.3
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    • pp.199-205
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    • 2003
  • It has been considered that genus Cosmarium including Staurastrum had the problems in grouping by morphological characters. Sequence data for the Cytochrome Oxidase subunit III (coxIII) were employed to compare with taxa of two divisions of this genus, with sections in each, for evaluating the taxonomic stability of these morphological characters. The division and section systems were not coincided with the phylogeny inferred from coxIII sequences, as the previous reports from us using nuclear rDNA ITS and chloroplast rbcL sequence comparisons in this genus. Two taxa of Staurastrum were not placed within a same clade each other, and one taxon of these was grouped in Arthrodesmus clade. Two genera, Cosmarium and Staurastrum, cannot be regarded as monophyletic from this result. Mitochondrial coxIII gene was considered as a useful phylogenetic tool to evaluate evolutionary relationships of desmids as in the case of land plants.