• Journal of Bio-Environment Control
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• v.22 no.3
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• pp.256-261
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• 2013

The spacing between plug cells and cell volume of each plug cell for nursing tomato seedlings were studied to know the effects on seedling growth and early yield. There were four treatments. The spacing of plug cells was done (OK) or not (NO) in case of cell spacing. The cell number in a plug tray was set to 40 or 50 in case of cell volume. The growth environment and irrigation regime were the same in all of the treatments during the experiment period. The photosynthetic rates, seedling qualities, yield and yield speed were significantly affected by both of the treatments. The photosynthetic rates and seedling qualities were the best in 40S-OK following by 50S-OK, 40S-NO, and 50S-NO while the yield was the best in 40S-OK following by 40S-NO, 50S-OK, 50S-NO. It means the spacing gives more impact than the cell volume in the stage of nursing but the cell volume gives more impact than the spacing after the stage of nursing. In the conclusion the spacing of plug cells in appropriate nursing stage is needed with the appropriate cell volume to make high quality of seedlings and high yield.

• The Korean Journal of Physiology and Pharmacology
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• v.2 no.1
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• pp.69-76
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• 1998

Cis-diamminedichloroplatinum II (cisplatin), an effective antitumor agent, induces acute renal failure by unknown mechanisms. To investigate direct toxic effects of cisplatin in the renal proximal tubular transport system, OK cell line was selected as a cell model and $Na^+/H^+$ antiport activity was evaluated during a course of cisplatin treatment. The cells grown to confluence were treated with cisplatin for 1 hour, washed, and incubated for up to 48 hours. At appropriate intervals, cells were examined for $Na^+/H^+$ antiport activity by measuring the recovery of intracellular pH (pHi) after acid loading. Cisplatin of less than 50 ${\mu}M$ induced no significant changes in cell viability in 24 hours, but it decreased the viability markedly after 48 hours. In cells exposed to 50 ${\mu}M$ cisplatin for 24 hours, the $Na^+-dependent$ pHi recovery (i.e., $Na^+/H^+$ antiport) was drastically inhibited with no changes in the $Na^+-independent$ recovery. Kinetic analysis of the $Na^+-dependent$ pHi recovery indicated that the Vmax was reduced, but the apparent Km was not altered. The cellular $Na^+$ and $K^+$ contents determined immediately before the transport measurement appeared to be similar in the control and cisplatin group, thus, the driving force for $Na^+-coupled$ transport was not different. These results indicate that cisplatin exposure impairs the $Na^+/H^+$ antiport capacity in OK cells. It is, therefore, possible that in patients treated with a high dose of cisplatin, proximal tubular mechanism for proton secretion (hence $HCO_3^-$ reabsorption) could be attenuated, leading to a metabolic acidosis (proximal renal tubular acidosis).

• Proceedings of the PSK Conference
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• 2002.10a
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• pp.256.2-257
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• 2002

Intestinal epithelial cells can produce cytokines and chemokines that play an important role in the mucosal immune response. Regulation of this secretion is important to prevent inflammatory tissue damage. Lonicera japonica have been shown to inhibit inflammation. We tested the effect of luteolin, a major ingredient of Lonicera japonica, on TNF-${\alpha}$-stimulated IL-8 secretion from lntestinal epithelial cells. (omitted)

• Proceedings of the PSK Conference
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• 2002.10a
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• pp.291.2-291.2
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• 2002

For the safety evaluation of adenovirus-mediated gene therapy. we have investigated gene and protein expression after transduction of adenoviral vector (Ad5CMV-p16) which contains tumor suppressor gene. p161NK4$\alpha$ in human non-small cell lung cancer (A549) cells. We compared the differential gene expression level in the A549 cells treated with Ad5CMV (null type) and Ad5CMV-p16 virus. respectively. by using cDNA membrane chip and oligonucleotide chip. (omitted)

• The Korean Journal of Physiology and Pharmacology
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• v.7 no.3
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• pp.187-191
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• 2003

$Na^+/H^+$ exchanger (NHE) has a critical role in regulation of intracellular pH (pHi) in the renal proximal tubular cells. It has recently been shown that dopamine inhibits NHE in the renal proximal tubules. Nevertheless, there is a dearth of information on the effects of long-term (chronic) dopamine treatment on NHE activities. This study was performed to elucidate the pHi regulatory mechanisms during the chronic dopamine treatments in renal proximal tubular OK cells. The resting pHi was greatly decreased by chronic dopamine treatments. The initial rate and the amplitude of intracellular acidification by isosmotical $Na^+$ removal from the bath medium in chronically dopamine-treated cells were much smaller than those in control. Although it seemed to be attenuated in $Na^+$-dependent pH regulation system, $Na^+$-dependent pHi recovery by NHE after intracelluar acid loading in the dopamine-treated groups was not significantly different from the control. The result is interpreted to be due to the balance between the stimulation effects of lower pHi on the NHE activity and counterbalance by dopamine. Our data strongly suggested that chronic dopamine treatment increased intrinsic intracellular buffer capacity, since higher buffer capacity was induced by lower resting pHi and this effect could attenuate pHi changes under extracellular $Na^+$-free conditions in chronically dopamine-treated cells. Our study also demonstrated that intracellular acidification induced by chronic dopamine treatments was not mediated by changes in NHE activity.

• Proceedings of the Materials Research Society of Korea Conference
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• 2007.05a
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• pp.19.2-19.2
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• 2007

• Bulletin of the Korean Chemical Society
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• v.22 no.10
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• pp.1067-1068
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• 2001

• Reproductive and Developmental Biology
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• v.36 no.4
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• pp.291-294
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• 2012

Embryonic stem cell classically cultured on feeder layer with FBS contained ES medium. Feeder-free mouse ES cell culture systems are essential to avoid the possible contamination of nonES cells. First we determined the difference between ES cell and MEF by Oct4 population. We demonstrate to culture and to induce differentiation on feeder free condition using a commercially available mouse ES cell lines.

• Proceedings of the Korean Vacuum Society Conference
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• 2005.08a
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• pp.67-67
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• 2005

• KSBB Journal
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• v.26 no.3
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• pp.183-188
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• 2011

Adult stem cells, which have characteristic of self-renewal and multipotency, are specialized cell types, responsible for the tissue regeneration of the damaged tissue. Recent studies suggest that stem cells senescence (or stem cells' ageing) is closely associated with the variety of ageing-related phenotypes such as tissue atrophy, degenerative diseases and onset of cancers. During ageing, declining of stem cells function and subsequently occurring mal-differentiation of stem cells would be important to understand the biological process of development of ageing-related phenotypes such as tissue degenerations and cancers. This review focuses on the DNA damage stress as a cause of senescence of stem cells and their mal differentiation, which is closely link to defect of regeneration potentials and neoplastic transformation. Understanding of molecular mechanisms governingsuch events is likely to have important implications for developing novel avenues for balancing tissue homeostasis longer period of time, further leading to 'Healthy ageing'.