• Bulletin of the Korean Chemical Society
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• v.25 no.7
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• pp.1003-1008
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• 2004

A novel class of alkoxybenzylcyanoguanidine analogs as the inhibitors of restenosis was discovered, which showed the inhibitory effects on angiotensin II-induced cell proliferation, determined by $[^3H]$thymidine incorporation method. The compound, N'-(4-nitrophenyl)guanidine analog 19, showed 62% inhibition of $[^3H]$thymidine incorporation at 1 ${\mu}M$ concentration. In addition, the compound 19 inhibited intimal thickening dose-dependently after balloon injury, which suggests the therapeutic potential for restenosis.

• Proceedings of the Korean Society of Life Science Conference
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• 2005.04a
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• pp.52-55
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• 2005

• Journal of the Korea Academia-Industrial cooperation Society
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• v.14 no.7
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• pp.3582-3588
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• 2013

Expressed sequence tag (EST) library was constructed from A. tamarense. Base sequences of EST clones were analyzed and saxitoxin biosynthesis-related genes were cloned. Sequences of 827 clones were analyzed and 564 EST were functionally clustered using Blast searches against GenBank. Main genes in the EST had functions on cellular organization, cell metabolism, energy, cell cycle and DNA processing, cellular transport and transport, cell rescue, defense, death and aging, and transcription. Moreover, expression of S-adenosylmethionine synthetase and H2A histone family genes were increased in the toxic A. tamarense. These results show that two genes could be a good biomarkers for the detection of saxitoxin biosynthesis in the A. tamarense.

• IMMUNE NETWORK
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• v.11 no.3
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• pp.169-174
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• 2011

Background: NADPH oxidase (NOX) modulates cell proliferation, differentiation and immune response through generation of reactive oxygen species. Particularly, NOX2 is recently reported to be important for regulating Treg cell differentiation of CD4+ T cells. Methods: We employed ovalbumin-induced airway inflammation in wild-type and NOX2-deficient mice and analyzed tissue histopathology and cytokine profiles. Results: We investigated whether NOX2-deficiency affects T cell-mediated airway inflammation. Ovalbumin injection which activates T cell-mediated allergic response increased airway inflammation in wild-type mice, as evidenced by increased immune cell infiltration, allergic cytokine expression, and goblet cell hyperplasia in the lung. Interestingly, NOX2 knockout (KO) mice were more susceptible to allergen-induced lung inflammation compared to wild-type mice. Immune cells including neutrophils, lymphocytes, macrophages, and eosinophils were drastically infiltrated into the lung of NOX2 KO mice and mucus secretion was substantially increased in deficiency of NOX2. Furthermore, inflammatory allergic cytokines and eotaxin were significantly elevated in NOX2 KO mice, in accordance with enhanced generation of inflammatory cytokines interleukin-17 and interferon-${\gamma}$ by CD4+ T cells. Conclusion: These results indicate that NOX2 deficiency favorably produces inflammatory cytokines by T cells and thus increases the susceptibility to severe airway inflammation.

• Journal of Microbiology and Biotechnology
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• v.27 no.4
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• pp.694-700
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• 2017

Clostridium difficile, which causes pseudomembranous colitis, releases toxin A and toxin B. These toxins are considered to be the main causative agents for the disease pathogenesis, and their expression is associated with a marked increase of apoptosis in mucosal epithelial cells. Colonic epithelial cells are believed to form a physical barrier between the lumen and the submucosa, and abnormally increased mucosal epithelial cell apoptosis is considered to be an initial step in gut inflammation responses. Therefore, one approach to treating pseudomembranous colitis would be to develop agents that block the mucosal epithelial cell apoptosis caused by toxin A, thus restoring barrier function and curing inflammatory responses in the gut. We recently isolated an antimicrobial peptide, Periplanetasin-2 (Peri-2, YPCKLNLKLGKVPFH) from the American cockroach, whose extracts have shown great potential for clinical use. Here, we assessed whether Peri-2 could inhibit the cell toxicity and inflammation caused by C. difficile toxin A. Indeed, in human colonocyte HT29 cells, Peri-2 inhibited the toxin A-induced decrease in cell proliferation and ameliorated the cell apoptosis induced by this toxin. Moreover, in the toxin A-induced mouse enteritis model, Peri-2 blocked the mucosal disruption and inflammatory response caused by toxin A. These results suggest that the American cockroach peptide Peri-2 could be a possible drug candidate for addressing the pseudomembranous colitis caused by C. difficile toxin A.

• Journal of Physiology & Pathology in Korean Medicine
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• v.21 no.5
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• pp.1170-1175
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• 2007

We have examined the effect of water extract of Phellinus linteus, a raw material of Korean traditional herbal medicine, on the induction of HL-60 cell differentiation. The proliferation of HL-60 cell was inhibited dose-dependently by treatment with various doses of P. linteus extract. It also caused a significant change in NBT reduction (7.5 times). The expression of CD11b and CD14 was increased in the cells treated with the extract, especially in those arrested at G0/G1 stage, which suggested that some components in P. Linteus extract induced HL-60 cell differentiation to granulocytic and monocyte lineages. Moreover, the expression levels of $p21^{WAF1/CIP}$ and $p27^{KIP}$ were up-regulated during HL-60 cell differentiation induced by P. Linteus extract. These results together suggest that P. Linteus extract contains potential HL-60 cell differentiation agents.

• Journal of Microbiology
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• v.37 no.3
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• pp.128-135
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• 1999

Among oil-degrading microorganisms isolated from oil-polluted industrial areas, one yeast strain showed high degradation activity of aliphatic hydrocarbons. From the analyses of 18S rRNA sequences, fatty acid, coenzyme Q system, G+C content of DNA, and biochemical characteristics, the strain was identified as Yarrowia lipolytica 180. Y. lipolytica 180 degraded 94% of aliphatic hydrocarbons in minimal salts medium containing 0.2% (v/v) of Arabian light crude oil within 3 days at 25$^{\circ}C$. Optimal growth conditions for temperature, pH, NaCl concentration, and crude oil concentration were 30$^{\circ}C$, pH 5-7, 1%, and 2% (v/v), respectively. Y. lipolytica 180 reduced surface tension when cultured on hydrocarbon substrates (1%, v/v), and the measured values of the surface tension were in the range of 51 to 57 dynes/cm. Both the cell free culture broth and cell debris of Y. lipolytica 180 were capable of emulsifying 2% (v/v) crude oil by itself. They were also capable of degrading crude oil (2%). The strain showed a cell surface hydrophobicity higher than 90%, which did not require hydrocarbon substrates for its induction. These results suggest that Y. lipolytica has high oil-degrading activity through its high emulsifying activity and cell hydrophobicity, and further indicate that the cell surface is responsible for the metabolism of aliphatic hydrocarbons.

• Food Science and Biotechnology
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• v.18 no.4
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• pp.971-977
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• 2009

The most abundant tea catechin, epigallocatechin-3-gallate (EGCG), has been reported to inhibit cell proliferation and induce apoptosis in many types of cancer cells. In the present study, effects of EGCG on the growth of oral epithelial cells including CAL-27 oral squamous carcinoma cells and dysplastic oral keratinocytes (DOK) were investigated. EGCG inhibited growth of CAL-27 cells and DOK with $IC_{50}$ of 14.4-21.0 and 5.8-14.2 ${\mu}M$ after 24 and 48 hr incubation, respectively. EGCG was significantly less effective in inhibiting DOK growth. The effects of EGCG, however, were dramatically less pronounced in the presence of superoxide dismutase (SOD) and catalase. Inhibitory effects of EGCG on CAL-27 cell growth were also much less pronounced in the presence of fetal bovine serum (FBS). EGCG induced caspase-3 activation in both CAL-27 and DOK cells in a serum free condition without SOD/catalase; in the presence of 10% FBS and SOD/catalase, EGCG, even at 100 ${\mu}M$, did not affect cell growth. The present results indicate that EGCG inhibited oral cell growth with higher potency to more malignant CAL-27 cells than DOK, and the effects were markedly altered by SOD/catalase and serum content in media.

• Journal of Powder Materials
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• v.27 no.2
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• pp.119-125
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• 2020

One of the promising candidates for accident-tolerant fuel (ATF), a ceramic microcell fuel, which can be distinguished by an unusual cell-like microstructure (UO₂ grain cell surrounded by a doped oxide cell wall), is being developed. This study deals with the microstructural observation of the constituent phases and the wetting behaviors of the cell wall materials in three kinds of ceramic microcell UO₂ pellets: Si-Ti-O (STO), Si-Cr-O (SCO), and Al-Si-Ti-O (ASTO). The chemical and physical states of the cell wall materials are estimated by HSC Chemistry and confirmed by experiment to be mixtures of Si-O and Ti-O for the STO; Si-O and Cr-O for SCO; and Si-O, Ti-O, and Al-Si-O for the ASTO. From their morphology at triple junctions, UO₂ grains appear to be wet by the Si-O or Al-Si-O rather than other oxides, providing a benefit on the capture-ability of the ceramic microcell cell wall. The wetting behavior can be explained by the relationships between the interface energy and the contact angle.

• Environmental Engineering Research
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• v.10 no.5
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• pp.227-238
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• 2005

The characteristics of nitrogen removal by the free cell and the immobilized cell of R. capsulatus were investigated. Denitrification by R. capsulatus cells resulted in reduction of ORP with the rapid depletion of DO and the increase of pH. Without accumulation of nitrite, the removal efficiencies of ${NO_3}^-$-N for the free cell and the immobilized cell were 99.1 and 99.3%, respectively. During the three-month experiment of goldfish breeding equipped with a water-purification biofilter, the average values of pH and total cell numbers present in an aquarium were not significantly different between water-purification system and the control. The average concentrations of ${NH_4}^+$-N and ${PO_4}^{2-}$-P in water-purification system were relatively low, compared to that in the control. Goldfish died at $11^{th}$, $16^{th}$, $43^{rd}$, and $67^{th}$ days in the control, while goldfish died at $10^{th}$, $20^{th}$, and $39^{th}$ days in the water-purification system. On the days of goldfish's death, the total concentrations of nitrogenous compounds except for ${NO_2}^--N$ were higher than those on the other days of the experiment, especially with the concentrations of ${NH_4}^+$-N ranging from 7.4 to 13.5 mg/L. The water-purification system also showed the less turbidity of water with more active movement of goldfish than the control. PVA gel beads showed almost the full denitrifying ability even after the long-term experiment. As a result, the water-purification system was effective to remove nitrogenous compounds with better survival of goldfish.