• Journal of Microbiology and Biotechnology
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• v.33 no.5
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• pp.591-599
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• 2023

Fisetin is a bioactive flavonol molecule and has been shown to have antioxidant potential, but its efficacy has not been fully validated. The aim of the present study was to investigate the protective efficacy of fisetin on C2C12 murine myoblastjdusts under hydrogen peroxide (H₂O₂)-induced oxidative damage. The results revealed that fisetin significantly weakened H₂O₂-induced cell viability inhibition and DNA damage while blocking reactive oxygen species (ROS) generation. Fisetin also significantly alleviated cell cycle arrest by H₂O₂ treatment through by reversing the upregulation of p21WAF1/CIP1 expression and the downregulation of cyclin A and B levels. In addition, fisetin significantly blocked apoptosis induced by H₂O₂ through increasing the Bcl-2/Bax ratio and attenuating mitochondrial damage, which was accompanied by inactivation of caspase-3 and suppression of poly(ADP-ribose) polymerase cleavage. Furthermore, fisetin-induced nuclear translocation and phosphorylation of Nrf2 were related to the increased expression and activation of heme oxygenase-1 (HO-1) in H₂O₂-stimulated C2C12 myoblasts. However, the protective efficacy of fisetin on H₂O₂-mediated cytotoxicity, including cell cycle arrest, apoptosis and mitochondrial dysfunction, were greatly offset when HO-1 activity was artificially inhibited. Therefore, our results indicate that fisetin as an Nrf2 activator effectively abrogated oxidative stress-mediated damage in C2C12 myoblasts.

• Korean Journal of Legislative Studies
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• v.25 no.2
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• pp.5-33
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• 2019

This study aims to explore the implications of the 2019 European Parliament elections. Existing studies show that European elections serve as secondary elections dominated by domestic issues. However, the 2019 European elections have highlighted pan-European issues such as the Brexit negotiations and the rise of far-right populism, with voter turnout also rising sharply to 50.62%, which is the highest record since the 2000s. There was also a significant change in the number of parliamentary seats held by each political group. First, the European People's Party(EPP) and the Progressive Alliance of Socialists and Democrats(S&D), which had hitherto led the European Parliament, failed to achieve a majority. Second, the number of seats won by Renew Europe, a new liberal-centrist group, was considerably high. Third, the far-right groups organized a full-fledged political force by rallying around the Identity and Democracy(ID) group. The rise of liberal-centrism can be explained as a reaction to the popularity of anti-European populism. Renew Europe's emphasis on open-market competition has created a different issue, especially since the center-left and center-right groups have stressed on the need for state intervention in employment, welfare, security and immigration control. Along with far-right populism, liberal centrism has also reshuffled Europe's political cleavage, and the conflict between 'liberalism' and 'protectionism' has become more evident in the European Parliament.

• Proceedings of the Plant Resources Society of Korea Conference
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• 2023.04a
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• pp.17-17
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• 2023

Chrysanthemum zawadskii (C. zawadskii) is used in traditional East Asian medicine for the treatment of various diseases, including inflammatory disease. However, it has remained unclear whether extracts of C. zawadskii inhibit inflammasome activation in macrophages. The present study assessed the inhibitory effect of an ethanol extract of C. zawadskii (CZE) on the activation of the inflammasome in macrophages and the underlying mechanism. Bone marrow[-derived macrophages (BMDMs) were obtained from wild-type C57BL/6 mice. The release of IL-1β and lactate dehydrogenase in response to nucleotide-binding oligomerization domain-like receptor (NLR) family pyrin domain containing 3 (NLRP3) inflammasome activators, such as ATP, nigericin and monosodium urate (MSU) crystals, was significantly decreased by CZE in lipopolysaccharide(LPS)-primed BMDMs. Western blotting revealed that CZE inhibited ATP-induced caspase-1 cleavage and IL-1β maturation. To investigate whether CZE inhibits the priming step of the NLRP3 inflammasome, we confirmed the role of CZE at the gene level using RT-qPCR. CZE also downregulated the gene expression of NLRP3 and pro-IL-1β as well as NF-κB activation in BMDMs in response to LPS. Apoptosis associated speck-like protein containing a caspase-recruitment domain (CARD) oligomerization and speck formation by NLRP3 inflammasome activators were suppressed by CZE. By contrast, CZE did not affect NLR family CARD domain containing protein 4 (NLRC4) or absent in melanoma 2 (AIM2) inflammasome activation in response to Salmonella typhimurium and poly(dA:dT) in LPS-primed BMDMs, respectively. The results revealed that three key components of CZE, namely linarin, 3,5-dicaffeoylquinic acid and chlorogenic acid, decreased IL-1β secretion in response to ATP, nigericin and MSU. These findings suggest that CZE effectively inhibited activation of the NLRP3 inflammasome.

• Korean Journal of Clinical Laboratory Science
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• v.56 no.1
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• pp.73-84
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• 2024

A pulsed electromagnetic field (PEMF) enhances the efficacy of several anticancer drugs. Doxorubicin (DOX) is an anticancer agent used to treat various malignancies, including breast cancer. This study examined whether a PEMF increases the anticancer effect of DOX on MCF-7 human breast cancer cells and elucidated the underlying mechanisms affected by PEMF stimulation in DOX-treated MCF-7 human breast cancer cells. A cotreatment with DOX and a PEMF potentiated the reduction in MCF-7 cell viability compared to the treatment with DOX alone. The PEMF elevated DOX-induced G1 arrest by affecting cyclin-dependent kinase 2 phosphorylation and the expression of G1 arrest-related molecules, including p53, p21, cyclin E2, and polo like kinase 1. In addition, PEMF increased the DOX-induced upregulation of proapoptotic proteins, such as Fas and Bcl-2-associated X, and the downregulation of antiapoptotic proteins, including myeloid leukemia 1 and survivin. PEMF promoted the DOX-induced activation of caspases-8, -9, and -7 and poly (adenosine diphosphate-ribose) polymerase cleavage in MCF-7 cells. In conclusion, PEMF enhances the anticancer activity in DOX-treated MCF-7 breast cancer cells by increasing G1 cell cycle arrest and caspase-dependent apoptosis. These findings highlight the potential use of a PEMF as an adjuvant treatment for DOX-based chemotherapy against breast cancer.

• Biomolecules & Therapeutics
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• v.32 no.3
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• pp.329-340
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• 2024

Mangiferin is a kind of natural xanthone glycosides and is known to have various pharmacological activities. However, since the beneficial efficacy of this compound has not been reported in retinal pigment epithelial (RPE) cells, this study aimed to evaluate whether mangiferin could protect human RPE ARPE-19 cells from oxidative injury mimicked by hydrogen peroxide (H₂O₂). The results showed that mangiferin attenuated H₂O₂-induced cell viability reduction and DNA damage, while inhibiting reactive oxygen species (ROS) production and preserving diminished glutathione (GSH). Mangiferin also antagonized H₂O₂-induced inhibition of the expression and activity of antioxidant enzymes such as manganese superoxide dismutase and GSH peroxidase, which was associated with inhibition of mitochondrial ROS production. In addition, mangiferin protected ARPE-19 cells from H₂O₂-induced apoptosis by increasing the Bcl-2/Bax ratio, decreasing caspase-3 activation, and blocking poly(ADP-ribose) polymerase cleavage. Moreover, mangiferin suppressed the release of cytochrome c into the cytosol, which was achieved by interfering with mitochondrial membrane disruption. Furthermore, mangiferin increased the expression and activity of heme oxygenase-1 (HO-1) and nuclear factor-erythroid-2 related factor 2 (Nrf2). However, the inhibition of ROS production, cytoprotective and anti-apoptotic effects of mangiferin were significantly attenuated by the HO-1 inhibitor, indicating that mangiferin promoted Nrf2-mediated HO-1 activity to prevent ARPE-19 cells from oxidative injury. The results of this study suggest that mangiferin, as an Nrf2 activator, has potent ROS scavenging activity and may have the potential to protect oxidative stress-mediated ocular diseases.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.6 no.4
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• pp.265-273
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• 2001

The sea urchin has been used as sea food in many countries. This species has also been an important organism of embryological studies for more than a century. In recent years, sea urchin embryos are being used as testing materials for toxicity of pollutants and toxins. Usefulness of sea urchin embryos as experimental models comes from the easiness in obtaining sea urchin samples and a lot of gametes, in rearing embryos in the laboratory, in observing the cellular movement and organ formation during the embryogenesis and in manipulating blastomeres and genetic maferials. The sea urchin in itself is a key organism for the understanding of deuterostome evolution from the protostomes and of indirect development of marine invertebrates which undergo the planktotrophic larval stage. A fertilized sea urchin egg goes through rapid cleavage and becomes a 60 cell embryo 7hr after fertilization. It then develops into a morula, a blastula, a gastrula and finally a pluteus larva approximately 70 hr after fertilization. At the 60 cell stage, the embryo comprises of five territories that express territory-speciflc genes and later form different organs. Micromeres at the vegetal pole ingress into the blastoceol and become the primary mesenchyme cells(PMCs). PMCs express genes involved in skeletogenesis such as SM30, SM37, SM50, PM27, msp130. Among the genes, SM37 and SM50 are considered to be members of a gene family which is characterized by early blastula expression, Glycine-Proline-Glutamine rich repeat structures and spicule matrix forming basic proteins. Genetic studies on the sea urchin embryos help understand the molecular basis of indirect development of marine invertebrates and also of the biomineralization common to the animal kingdom.

• Journal of the Korean Chemical Society
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• v.37 no.2
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• pp.237-243
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• 1993

The primary and secondary structure of the 5S rRNA isolated from Xanthomonas celebensis were determined by enzymatic and chemical degradation methods. It consists of 119 nucleotides and contains no modified nucleosides. As with the 5S rRNAs of X. maltophilia and X. citri, it contains an additional uridine residue on the 5'-terminus. Its secondary structure was almost identical to the models previously proposed by us for the 5S rRNA of two Xanthomonas species. Its secondary structure consists of five helices, five loops and two bulges. The tertiary interactions in the 5S rRNA molecule were analyzed by Fe(II)-EDTA treatment and hybridization method using deoxyhexamer. From the fact that some adenine residues in loop M, region $I_1-C$, loop $H_1$, and loop $H_2$ become susceptible to diethylpyrocarbonate when the 5S rRNA was hybridized with deoxyhexamer complementary to the sequence $U_{35}CCCAU_{40}$ and that some nucleotide residues in loop M, loop $H_1$ and region $D-I_2$ become resistant Fe(II)-EDTA cleavage in the presence of $Mg^{2+}$, it is presumed that loops $H_1$ and $H_2$ interact with loop M in some way. In the tertiary interaction, the regions $I_1-C$ and $D-I_2$ seem to act as hinges in folding the stems $B-I_1-C$ and $D-I_2-E.$ It was found that loop $H_1$ changes into a smaller loop of three bases by forming noncanonical A : C base-pairs ih acidic environment.

• Journal of Embryo Transfer
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• v.20 no.1
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• pp.55-62
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• 2005

This study was undertaken to access the effect of collection methods on the collection efficiency, blastocyst rate and pregnancy rate after IVP embryo transfer. The ovaries of Hanwoo were obtained from an abattoir and kept on 25 to $28^{\circ}C$ and transported to laboratory within 4 hrs. The oocytes were collected by aspiration of follicles $(2\~6\;mm)$ with or without slicing of ovaries after aspiration. The oocytes were matured in vitro (IVM) for 20 to 24 hrs in TCM-199 supplemented with $10\%$ fetal bovine serum at $39^{\circ}C$ under $5\%\;CO_{2}$ in air. Following routine IVM/IVF procedure, the oocytes and presumed zygotes were cultured for three day in CRlaa medium with BSA. The cumulus cells at 2 to 8-cell stage of embryos removed then the embryos and were cultured in CRlaa medium containing $10\%$ fetal bovine serum in $5\%\;CO_{2}$ at $39^{\circ}C$. The fresh blastocysts cultured for 7 to 9 days were transferred into recipients. The numbers of oocytes recovered form two different methods, the aspiration and slicing after aspiration, were compared to know what. The number of oocytes per ovary was 8.2 and 6.5 in aspiration combining slicing, and aspiration groups, respectively (p<0.05). The cleavage rate in aspiration method are significantly (p<0.05) high than those in slicing post aspiration $(27.9\%)$, and aspiration $(25.5\%)$. The pregnancy .ate in aspiration method $(62.5\%)$ was high than that in slicing method after aspiration $(54.4\%)$. The pregnancy rates of aspiration method and slicing method after aspiration in nullipara $(58.1\%\;vs\;68.2\%)$ was high than that in pluripara $(49.5\%\;vs\;53.2\%)$. The results obtained that the increased number of oocytes per ovary in slicing method after aspiration could be better than that in aspiration method. Pregnancy rate in aspiration method was slightly higher in than that in slicing method after aspiration.

• Journal of Life Science
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• v.16 no.3 s.76
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• pp.546-554
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• 2006

To understand antitumor activity of Zanthoxylum schinfolium, which has been used as an aromatic and medicinal plant in Korea, the cytotoxic effect of various organic solvent extracts of its leaves on human tumor cells were investigated. Among these extracts such as methanol extract (SL-13), methylene chloride extract (SL-14), ethyl acetate extract (SL-15), n-butanol extract (SL-16), and residual fraction (SL-17), SL-14 appeared to contain the most cytotoxic activity against leukemia and breast cancer cells tested. The methylene chloride extra.1 (SL-14) possessed an apoptogenic activity causing apoptotic DNA fragmentation of human acute leukemia Jurkat T cells via mitochondrial cytochrome c release into cytoplasm, subsequent activation of caspase-9 and caspase-3, and cleavage of PARP, which could be negatively regulated by antiapoptotic protein Bcl-xL. The GC-MS analysis of SL-14 revealed that the twenty-two ingredients of SL-14 were 9,19-cyclolanost-24-en-3-ol (15.1%), 2-a-methyl-17, b-hop-21-ene (15.1%), 15-methyl-2,3-dihydro-1H benzazepin (11.95%), phytol (10.38%), lupeol (9.92%), 12-methylbenzofuran (8.23%), hexadecanoic acid (5.96%), cis,cis,cis-9,12,15-octadecatrienoic acid-methyl-ester (5.49%), 9,12,15-octadecatrienoic acid-methylester (3.59%), 15-methyl-4-(1-methylethylidene)-2-(4-nitrophenyl) (3.36%), hexadecanoic acid methyl ester (1.93%), vitamine E (1.88%), beta-amyrin (0.96%), and auraptene (0.89%). These results demonstrate that the cytotoxicity of the methylene chloride extract of the leaves of Z. schinifolium toward Jurkat T cells is mainly attributable to apoptosis mediated by mitochondria-dependent caspase cascade regulated by Bcl-xL, and provide an insight into the mechanism underlying antitumor activity of the edible plant Z. schinifolium.

• Korean Journal of Animal Reproduction
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• v.25 no.1
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• pp.19-28
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• 2001

The present study was undertaken to investigate the effects of cooling rate and equilibration time on the survival, in vitro maturation and development to embryos of frozen-thawed bovine immature oocytes(Germinal Vesicle Stage). The cryoprotectants are used 10% ethylene glycol(EG) as permeating cryoprotectant and 0.05M soc.ose(S) or trehalose(T) as low molecular weight nonpermeating cryoprotectants and 5% ficoll(F) or polyvinylpyrrolidone(PVP) as high molecular weight nonpermeating cryoprotectants. Four freezing solution were uysed in this experiment(EFT: 10% EG + 5% F + 0.05M T, EFS: 10% EG + 5% F + 0.05M S, EPT: 10% EG + 5% P + 0.05M T, EPS: 10% EG + 5% P + 0.05M S). The best equilibration time and freezing solution was 15 min in EPT(83% survival rate of frozen-thawed bovine immature oocytes). When frozen-thawed bovine oocytes were cultured following IVM and IVF, there was no significant difference in cleavage and development rates among the EFT, EFS, EPT and EPS solutions. When 9 blastocysts derived from frozen bovine oocytes were transferred to 6 recipients, two recipients were pregnant. And one was aborted at 45 days of pregnancy and the other had a stillbirth.