• Microbiology and Biotechnology Letters
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• v.28 no.1
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• pp.39-44
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• 2000

This study was carried out to develop a new starter culture for the fermented meat products. Nine strains of lactic acid bacteria isolated from kimchi inhibited the growth of Listeria monocytogenes. Among these nine strains, three strains showing antimicrobial activities against Escherichia coil, Staphylococcus aureus and Vibrio paraphaemolyticus were selected for further study. Growth of the strains was inhibited in MRS broth containing 5% of NaCl at $21^{\circ}C$, but not at $32^{\circ}C$. Nitrite depletion ratio of the strains was above 70% after 48h incubation at $21^{\circ}C$, and above 90% after 48h at $32^{\circ}C$ in MRS broth containing $200\mu$g/ml of nitrite, Nitrite concentration of cured meats and ground meats was depleted from 87.6% to 92.3% and from 45.5 to 640.6% by addition of the selected strains for 24h at $32^{\circ}C$, respectively. Three strains were identified as Lactobacillus plantarum(N4) and Lactobacillus lactis ssp. lactis(N-7, an-8).

• Journal of the Korean Society of Food Science and Nutrition
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• v.26 no.4
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• pp.549-555
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• 1997

Twenty species of lactic acid bacteria were isolated from Kimchi. Six species were identified as Lactobacillus sake, ten species as Leuconostoc mesenteroides and four species as Lactobacillus plantarum. The ability of these isolates to deplete nitrite during growth at 15, 20, 25 and 3$0^{\circ}C$ in MRS broth containing 250$\mu\textrm{g}$/$m\ell$ of nitrite was examined. Depletion of nitrite was high as the order of L. plantarum, L. sake and L. mesenteroides at all temperature tested, and the depletion activity was increased as the increase of growth temperatures. Especially, almost all of nitrites were utilized by L. plantarum during growth at all temperature ranges tested. L. plantarum and L. sake required induction periods for adapting to nitrite, but L. plantarum was remarkably depleted nitrite after two days of growth at 15$^{\circ}C$ and one day at 2$0^{\circ}C$, L. sake after one day of growth at both temperatures. Whereas, L. mesentero-ides did not require those periods at all temperature ranges tested.

• Journal of Acupuncture Research
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• v.19 no.5
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• pp.28-34
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• 2002

Objective : The aim of this research was to investigate the depressive effect of acupuncture on Gangap-point and depletion on Taech'u-point in stroke patients. Methods : We measured the blood pressure of the patients who were admitted in the Oriental Medical hopital of Dongeui medical center from 21. Oct. 2001. to 20. Jan. 2002. 19 stroke patients were devided into two groups. 12 patients were treated by acupunctured on Gangap-point. The other 7 patients were treated by depletion on Taech'u-point. The activity of daily living was measured. If systolic blood pressure was over 160 mmHg or diastolic blood pressure was over 90 mmHg, acupunctured on Gangap-point and depletion on Taech'u-point were performed. Then 30minutes and 60minutes later, systolic, diastolic blood pressure and pulse rates were measured Results : After 30 minute treatment. both acupuncture on Gnagap-point and depletion on Taech'u-point significantly depressed the systolic blood pressure. After 60 minute treatment. only depletion on Taech'u-point were statistically significant in depressing the systolic blood pressure. Pulse rates were not significantly changed. Conclusion : These results suggest that depletion on Taech'u-point is more effective in depressing the systolic blood pressure than acupuncture on Gnagap-point.

• Journal of Microbiology and Biotechnology
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• v.27 no.12
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• pp.2129-2140
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• 2017

Silibinin is the major active component of silymarin, extracted from the medicinal plant Silybum marianum. Silibinin has potent antibacterial activity; however, the exact mechanism underlying its activity has not been elucidated. Here, we investigated the novel mechanism of silibinin against Escherichia coli. Time-kill kinetic assay showed that silibinin possess a bactericidal effect at minimal inhibitory concentration (MIC) and higher concentrations (2-and 4-fold MIC). At the membrane, depolarization and increased intracellular $Ca^{2+}$ levels were observed, considered as characteristics of bacterial apoptosis. Additionally, cells treated with MIC and higher concentrations showed apoptotic features like DNA fragmentation, phosphatidylserine exposure, and caspase-like protein expression. Generally, apoptotic death is closely related with ROS generation; however, silibinin did not induce ROS generation but acted as a scavenger of intracellular ROS. These results indicate that silibinin dose-dependently induces bacterial apoptosis-like death, which was affected by ROS depletion, suggesting that silibinin is a potential candidate for controlling bacteria.

• The Korean Journal of Physiology and Pharmacology
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• v.23 no.6
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• pp.519-528
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• 2019

Mitochondrial dysfunction is closely associated with reactive oxygen species (ROS) generation and oxidative stress in cells. On the other hand, modulation of the cellular antioxidant defense system by changes in the mitochondrial DNA (mtDNA) content is largely unknown. To determine the relationship between the cellular mtDNA content and defense system against oxidative stress, this study examined a set of myoblasts containing a depleted or reverted mtDNA content. A change in the cellular mtDNA content modulated the expression of antioxidant enzymes in myoblasts. In particular, the expression and activity of glutathione peroxidase (GPx) and catalase were inversely correlated with the mtDNA content in myoblasts. The depletion of mtDNA decreased both the reduced glutathione (GSH) and oxidized glutathione (GSSG) slightly, whereas the cellular redox status, as assessed by the GSH/GSSG ratio, was similar to that of the control. Interestingly, the steady-state level of the intracellular ROS, which depends on the reciprocal actions between ROS generation and detoxification, was reduced significantly and the lethality induced by $H_2O_2$ was alleviated by mtDNA depletion in myoblasts. Therefore, these results suggest that the ROS homeostasis and antioxidant enzymes are modulated by the cellular mtDNA content and that the increased expression and activity of GPx and catalase through the depletion of mtDNA are closely associated with an alleviation of the oxidative stress in myoblasts.

• The Korean Journal of Zoology
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• v.34 no.2
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• pp.173-180
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• 1991

The objective of this experiment was to examine the effect of polyamine depletion by polyamine biosynthesis inhibitors on microbicidal activity and tumoricidal activity in mouse mac-rophages. $\alpha$ -Difluoromethylomithine (DFMO), inhibitor of putrescine and spernidine biosynthesis, treatment in vivo for 6-8 days reduced chemiluminescence levels in thioglycollate-, lipo-polysaccharide (LPS), and BCG-treated mouse macrophages. An DFMO treatment in vitro inhibited production of tumor necrosis factor (TNF), in dose-dependent manner, and tumoricidal activity by macrophages. The effect of polyamine depletion by MO on ThF production and tumoricidal activity could be reversed by the addition of exogenous putrescine. These result indicated that the obserbed effect of DFMO on macrophage activities were mediated through inhibition of polyamines are, must be, required for optimal activities of macrophages.

• Journal of Nutrition and Health
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• v.35 no.2
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• pp.223-228
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• 2002

The purpose of this study was to investigate the relationship between iron deficiency without anemia and physical performance in healthy women aged 20-21 yrs. Ten subjects with normal iron stores (serum ferritin $\geq$ 12$\mu\textrm{g}$/L: iron-sufficient group) and 11 subjects with iron depletion without anemia (serum ferritin < 12 $\mu\textrm{g}$/L and serum hemoglobin > 120 g/L: iron-depleted group) were chosen from a group of 50 women and were given physical-performance tests, including determinations of maximum oxygen consumption (VO$_2$ max) and ventilatory threshold. Iron status assessment included determination of hemoglobin, hematocrit, seam ferritin, total iron-binding rapacity, serum iron and transferrin saturation values. Dietary iron intake was assessed based on seven-day food intake records written by the subjects. Physical activity level was estimated by frequency questionnaires and two-week physical activity records were compiled daily by the subjects. Blood ferritin concentration was significantly lower in the iron-depleted group than in the iron-sufficient group (p < 0.05). However, other variables showing iron status was not different between the groups. There were no significant differences in body size, body composition and physical activity levels between the groups. Daily dietary iron, total protein and animal protein intakes of the iron-sufficient group were significantly higher than those of the iron depleted group. However, no differences were found in the amount of dietary vitamin C and fiber between the groups. The values for VO$_2$max and VO$_2$max corrected with weight or fat-free mass were not different between the groups. However, the ventilatory threshold was significantly higher in the iron sufficient group than in the iron-depleted group. The lower ventilatory threshold in the iron-depleted group suggests that iron depletion without anemia could diminish aerobic physical performance in young women. In addition, a significant correlation of physical performance to serum fferritin level was shown only in the iron depleted group.

• YAKHAK HOEJI
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• v.49 no.4
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• pp.355-364
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• 2005

A neurotoxin, 6-hydroxydopamine (6-OHDA) has long been used to form a Parkinson's disease (PD) model by inducing the lesion in catecholaminergic pathways, particularly the nigrostriatal dopamine (DA) pathway. Whereas l-deprenyl, a selective inhibitor of monoamine oxidase (MAO) type B, is now widely used in the treatment of PD, the precise action mechanism of the drug remains elusive. In this study, we investigated whether l-deprenyl shows protective effect against the DA depletion induced by 6-OHDA in rat brain, and against 6-OHDA-induced neurotoxicity and oxidative stress in catecholaminergic neuroblastoma SH-SY5Y cells that are known to lack MAO-B activity. Pretreatment of l-deprenyl significantly enhanced the striatal DA, 3,4-dihydroxyphenylacetic acid, homovanilic acid, and 3-methoxytyramine levels compared to the untreated 6-OHDA-lesioned rat, indicating that l-deprenyl pretreatment prevents 6-OHDA-induced depletion of not only striatal dopamine but also its metabolites. Treatment of 6-OHDA for 24hrs decreased the cell viability and increase the generation of ROS in dose-dependent manners. We further investigated whether caspase activity is involved in the action of l-deprenyl. Treatment of l-deprenyl $(0.1\~100{\mu}M)$ did not produce any changes in 6-OHDA-induced cleavage of poly (ADP-ridose) polymerase in SH-SY5Y cells. Our results suggest that the neuroprotective effect of l-deprenyl against 6-OHDA is due to its increased scavenger activity, but independent of inhibition of MAO-B or caspase-3 activation.

• The Korean Journal of Physiology and Pharmacology
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• v.22 no.4
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• pp.457-465
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• 2018

The expression of BCL-2 interacting cell death suppressor (BIS), an anti-stress or anti-apoptotic protein, has been shown to be regulated at the transcriptional level by heat shock factor 1 (HSF1) upon various stresses. Recently, HSF1 was also shown to bind to BIS, but the significance of these protein-protein interactions on HSF1 activity has not been fully defined. In the present study, we observed that complete depletion of BIS using a CRISPR/Cas9 system in A549 non-small cell lung cancer did not affect the induction of heat shock protein (HSP) 70 and HSP27 mRNAs under various stress conditions such as heat shock, proteotoxic stress, and oxidative stress. The lack of a functional association of BIS with HSF1 activity was also demonstrated by transient downregulation of BIS by siRNA in A549 and U87 glioblastoma cells. Endogenous BIS mRNA levels were significantly suppressed in BIS knockout (KO) A549 cells compared to BIS wild type (WT) A549 cells at the constitutive and inducible levels. The promoter activities of BIS and HSP70 as well as the degradation rate of BIS mRNA were not influenced by depletion of BIS. In addition, the expression levels of the mutant BIS construct, in which 14 bp were deleted as in BIS-KO A549 cells, were not different from those of the WT BIS construct, indicating that mRNA stability was not the mechanism for autoregulation of BIS. Our results suggested that BIS was not required for HSF1 activity, but was required for its own expression, which involved an HSF1-independent pathway.

• Molecules and Cells
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• v.46 no.6
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• pp.374-386
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• 2023

Thermal stress induces dynamic changes in nuclear proteins and relevant physiology as a part of the heat shock response (HSR). However, how the nuclear HSR is fine-tuned for cellular homeostasis remains elusive. Here, we show that mitochondrial activity plays an important role in nuclear proteostasis and genome stability through two distinct HSR pathways. Mitochondrial ribosomal protein (MRP) depletion enhanced the nucleolar granule formation of HSP70 and ubiquitin during HSR while facilitating the recovery of damaged nuclear proteins and impaired nucleocytoplasmic transport. Treatment of the mitochondrial proton gradient uncoupler masked MRP-depletion effects, implicating oxidative phosphorylation in these nuclear HSRs. On the other hand, MRP depletion and a reactive oxygen species (ROS) scavenger non-additively decreased mitochondrial ROS generation during HSR, thereby protecting the nuclear genome from DNA damage. These results suggest that suboptimal mitochondrial activity sustains nuclear homeostasis under cellular stress, providing plausible evidence for optimal endosymbiotic evolution via mitochondria-to-nuclear communication.