• Journal of Physiology & Pathology in Korean Medicine
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• v.20 no.2
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• pp.358-364
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• 2006

To investigate the possible mechanism of Drynariae Rhizoma extracts as a candidate of anti-cancer drug, I examined the effects of Drynariae Rhizoma extracts on the apoptosis of U937 cell line. MTT assay, flow cytometric analysis, SDS-polyacrylamide gel electrophoresis, Western blot analysis, and RT-PCR were performed. Drynariae Rhizoma extracts treatment reduced the cell viablilty of U937 cells in a dose-dependent manner, which was associated with induction of apoptotic cell death. Drynariae Rhizoma extracts treatment also reduced the levels of Bcl-xL anti-apoptotic protein expression and increased the levels of caspase-3, p53, pro-apoptotic protein, in U937 cells. RT-PCR data revealed that the level of bcl-2, bcl-xL mRNA expressions decreased in a dose-dependent manner. These findings suggest that Drynariae Rhizoma extracts may have induction of apoptotic cell death via regulation of several growth regulatory gene products. The abbreviations used are: FBS, fetal bovine serum; PBS, phosphate buffered saline; PI, propidium iodide; OD, optical density; DiOC6, 3,3-dihexyloxa carbcyanine iodide; MTT, 3 [4-5-dimethylthiazol-2-yl] -2-diphenyltetrazolium bromide.

• BMB Reports
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• v.46 no.2
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• pp.86-91
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• 2013

Glucose effects on the vegetative growth of Dictyostelium discoideum Ax2 were studied by examining oxidative stress and tetrahydropteridine synthesis in cells cultured with different concentrations (0.5X, 7.7 g $L^{-1}$; 1X, 15.4 g $L^{-1}$; 2X, 30.8 g $L^{-1}$) of glucose. The growth rate was optimal in 1X cells (cells grown in 1X glucose) but was impaired drastically in 2X cells, below the level of 0.5X cells. There were glucose-dependent increases in reactive oxygen species (ROS) levels and mitochondrial dysfunction in parallel with the mRNA copy numbers of the enzymes catalyzing tetrahydropteridine synthesis and regeneration. On the other hand, both the specific activities of the enzymes and tetrahydropteridine levels in 2X cells were lower than those in 1X cells, but were higher than those in 0.5X cells. Given the antioxidant function of tetrahydropteridines and both the beneficial and harmful effects of ROS, the results suggest glucose-induced oxidative stress in Dictyostelium, a process that might originate from aerobic glycolysis, as well as a protective role of tetrahydropteridines against this stress.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.51 no.3
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• pp.298-304
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• 2018

A single specimen of Gymnothorax pseudothyrsoideus (424.0 mm TL) belonging to the family Muraenidae, order Anguilliformes, was collected from Jeju Island, Korea, for the first time. The specimen is characterized by jaws closing completely, canine teeth on jaws, teeth not exposed when mouth is closed, ovoid posterior nostril, and body color ranging from yellowish brown to brownish with small dark spots aggregating to form larger spots that from approximately four irregular rows along the body. A comparison of mitochondrial DNA 16S rRNA sequences indicated that this specimen corresponds well with G. pseudothyrsoideus (K2P distance, d=0.002) but differs from other Gymnothorax species (11.9-13.7%). Therefore, the new Korean name "Geu-mul-nun-gom-chi" is proposed for the species G. pseudothyrsoideus.

• BMB Reports
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• v.47 no.7
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• pp.393-398
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• 2014

The role of Bax inhibitor-1 (BI-1) in the protective mechanism against apoptotic stimuli has been studied; however, as little is known about its role in death receptor-mediated cell death, this study was designed to investigate the effect of BI-1 on Fas-induced cell death, and the underlying mechanisms. HT1080 adenocarcinoma cells were cultured in high concentration of glucose media and transfected with vector alone (Neo cells) or BI-1-vector (BI-1 cells), and treated with Fas. In cell viability, apoptosis, and caspase-3 analyses, the BI-1 cells showed enhanced sensitivity to Fas. Fas significantly decreased cytosolic pH in BI-1 cells, compared with Neo cells, and this decrease correlated with BI-1 oligomerization, mitochondrial $Ca^{2+}$ accumulation, and significant inhibition of sodium-hydrogen exchanger (NHE) activity. Compared with Neo cells, a single treatment of BI-1 cells with the NHE inhibitor EIPA or siRNA against NHE significantly increased cell death, which suggests that the viability of BI-1 cells is affected by the maintenance of intracellular pH homeostasis through NHE.

• Parasites, Hosts and Diseases
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• v.41 no.4
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• pp.181-188
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• 2003

A new species of Acanthamoeba was isolated from a freshwater fish in Korea and tentatively named Acanthamoeba sp. YM-4 (Korean isolate YM-4). The trophozoites were $11.0-23.0{\;}{\mu\textrm{m}}$ in length and had hyaline filamentous projections. Cysts were similar to those of A. culbertsoni and A. royreba, which were previously designated as Acanthamoeba group III. Acanthamoeba YM-4 can survive at $40^{\circ}C$, and its generation time was 19.6 hr, which was longer than that of A. culbertsoni. In terms of the in vitro cytotoxicity of lysates, Acanthamoeba YM-4 was weaker than A. culbertsoni, but stronger than A. polyphaga. On the basis of the mortality of experimentally infected mice, Acanthamoeba YM-4 was found to be highly virulent. The isoenzymes profile of Acanthamoeba YM-4 was similar to that of A. royreba. An anti-Acanthamoeba YM-4 monoclonal antibody, McAY7, was found to react only with Acanthamoeba YM-4, and not with A. culbertsoni. Random amplified polymorphic DNA marker analysis and RFLP analysis of mitochondrial DNA and of 18S small subunit ribosomal RNA, placed Acanthamoeba YM-4 in a separate cluster on the basis of phylogenetic distances. Thus the Acanthamoeba Korean isolate YM-4 was identified as a new species, and assigned as Acanthamoeba sohi.

• Food Science and Biotechnology
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• v.15 no.4
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• pp.612-616
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• 2006

The protective effect of water extract of ash tree leaves (ALE) against oxidative damages was investigated in paracetamol-induced BALB/c mice. Biochemical analysis of anti-oxidative enzymes, immunoblot analyses of hepatic cytochrome P450 2El (CYP2E1), and the gene expression of tumor necrosis factor (TNF-${\alpha}$) were examined to determine the extract's protective effect and its possible mechanisms. BALB/c mice were divided into three groups: normal, paracetamol-administered, and ALE-pretreated groups. A single dose of paracetamol led to a marked increase in lipid peroxidation as measured by malondialdehyde (MDA). This was associated with a significant reduction in the hepatic antioxidant system, e.g., glutathione (GSH). Paracetamol administration also significantly elevated the expression of CYP2E1, according to immunoblot analysis, and of TNF-${\alpha}$ mRNA in liver. However, ALE pretreatment prior to the administration of paracetamol significantly decreased hepatic MDA levels. ALE restored hepatic glutathione and catalase levels and suppressed the expression of CYP2E1 and TNF-${\alpha}$ observed in inflammatory tissues. Moreover, ALE restored mitochondrial ATP content depleted by the drug administration. These results show that the extract of ash tree leaves protects against paracetamol-induced oxidative damages by blocking oxidative stress and CYP2E1-mediated paracetamol bioactivation.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.54 no.4
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• pp.568-573
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• 2021

A single leptocephalus specimen of Albula glossodonta belonging to the family Albulidae under the order Albuliformes, was collected from the southern sea of Korea in May 21, 2019. This species is distinguished from A. vulpes in the number of melanophores at the base of the caudal fin. In addition, our specimen was readily distinguished from A. argentea in having no melanophores on the operculum, at the base of the dorsal fin and in front of the pectoral fin. Also it was well distinguished from A. gilberti in having no melanophores on the operculum, in front of the pectoral fin and on the lateral body. A molecular analysis based on 467 bp sequences of the mitochondrial DNA 16S rRNA shows that the leptocephalus is well matched to A. glossodonta adult (K2P distance=0.002). We report the first occurrence of A. glossodonta leptocephalus in the Korean waters, and propose it's new Korean name, "Nam-bang-yeoeul-myeol".

• Quantitative Bio-Science
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• v.37 no.2
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• pp.103-111
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• 2018

This study was performed to investigate the cytoprotective effects of Stachys riederi var. japonica ethanol extract (SREE) to control oxidative stress induced by UVA-irradiation by examining antioxidant capacity and gene expression of cytochrome c using human dermal fibroblasts. The total polyphenolics and flavonoids in the SREE were 41.2 and 25.4 mg/g, respectively. At concentrations of 500 and $1000{\mu}g/mL$, the electron-donating ability of SREE was 48.6% and 82.0%, respectively, and the 2,2'-azino-(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) radical scavenging activity was 62.3% and 78.8%, respectively. These findings showed that SREE has a fairly good antioxidant capacity. As determined by an MTT assay, the maximum permissible level for treating SREE to human dermal fibroblasts was shown to be over $200{\mu}g/mL$. SREE ($200{\mu}g/mL$) significantly decreased cytochrome c mRNA and protein expression by 31.1% (p<0.001) and 38.8% (p<0.01), respectively. These findings suggest that SREE may protect human skin cells against mitochondrial-dependent apoptosis. Therefore, SREE seems to be a natural antioxidant to protect cells against oxidative stress induced by UVA-irradiation.

• Parasites, Hosts and Diseases
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• v.59 no.1
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• pp.89-95
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• 2021

Microcotyle sebastis is a gill monogenean ectoparasite that causes serious problems in the mariculture of the Korean rockfish, Sebastes schlegelii. In this study, we isolated the parasite from fish farms along the coasts of Tongyeong, South Korea in 2016, and characterized its infection, morphology and molecular phylogeny. The prevalence of M. sebastis infection during the study period ranged from 46.7% to 96.7%, and the mean intensity was 2.3 to 31.4 ind./fish, indicating that the fish was constantly exposed to parasitic infections throughout the year. Morphological observations under light and scanning electron microscopes of the M. sebastis isolates in this study showed the typical characteristics of the anterior prohaptor and posterior opisthaptor of monogenean parasites. In phylogenetic trees reconstructed using the nuclear 28S ribosomal RNA gene and the mitochondrial cytochrome c oxidase I gene (cox1), they consistently clustered together with their congeneric species, and showed the closest phylogenetic relationships to M. caudata and M. kasago in the cox1 tree.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.55 no.2
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• pp.146-153
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• 2022

The vertical distribution and abundance of icthyoplankton in the southern waters of Jeju Island during June 2020 were investigated. Fish eggs and larvae were identified using the mitochondrial DNA cytochrome c oxidase subunit I (mtDNA COI) and the 16S rRNA gene. During this period, fish eggs of 23 taxa belonging to 21 families and larvae of 27 taxa belonging to 25 families were collected. Fish eggs were located mostly from the surface to 30 m depth of the water column. Larvae were located from the surface to 80 m depth of the water column. Vertical distributions of fish eggs and larvae were influenced by oceanography conditions such as temperature, salinity, and thermocline depth. No discernible difference in mean thermocline depth was observed between day and night.