• KSBB Journal
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• v.13 no.3
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• pp.251-258
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• 1998

A structured kinetic model is proposed to describe cell growth and secondary metabolite, flavone glycosides, synthesis in batch suspension culture of Scutellaria baicalensis G. The model has been developed by representing the physiological state of cell described as the activity and viability which can be estimated based on the culture fluorescence. In the model, three type of cells are considered; active-viable, nonactive-viable and dead cells. Viable cell weight could be determined based on the relative fluorescence intensity. The flavone glycosides could be produced by both active-viable and non-active viable cells with a different production rate. And the model includes the cell expansion due to glucose concentration and death phase which accounts for the release of intracellular secondary metabolite into medium. Dependent variables include substrate concentration(glucose), cell mass(dry cell weight and fresh cell weight), product concentration(flavone glycosides), activity and viability. Satisfactory agreement between the model and experimental data is obtained from shake flask culture of Scutellaria baicalensis G. The proposed model can predict the cell growth and flavone glycosides synthesis as well as intermediate materials.

• 한국생물공학회:학술대회논문집
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• 2003.04a
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• pp.293-297
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• 2003

Glutathione and ascorbic acid have been shown to fulfill many essential functions in animal and plant growth, development, defence and protection against oxidative damage. Effects of glutathione and ascorbic acid were examined in transgenic N. tabacum cells producing hGM-CSF to determine the effects of the vitamins on growth and cell viability. In lag phase, cell viability was preserved by glutathione and ascorbic acid. Therefore, recombinant protein productivity was increased. The purpose of present study is to investigate the role of antioxidants in cold stress-induced apoptosis in plant suspension cells. Cold stress lowered cell viability and increased total genomic DNA fragmentation. Supplementing the cell cultures with glutathione and ascorbic acid inhibited cold stress-induced decrease in cell viability and increase in total genomic DNA fragmentation.

• Proceedings of the Korean Aquaculture Society Conference
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• 2003.10a
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• pp.84-85
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• 2003

조개류의 먹이생물인 미세조류를 대체할 수 있는 효모를 개발하기 위하여 빵효모 (Saccharomyces cerevisiae), Candida utilis, Klyveromyces fragilis 3종류의 효모를 대상으로 그 먹이효율을 실험하였다. 이들 3종류의 효모를 세포벽을 75, 50, 25% 제거한 것과 세포벽을 제거하지 않은 효모로 구분하여 Artemia를 대상으로 먹이효율을 조사한 후 가장 좋은 먹이효율을 보인 C. utilis를 조개류의 대표적 먹이생물인 Isoch교sis galbana 와 함께 진주담치 유생을 대상으로 먹이효율을 조사하였다. Artemia 실험결과 빵효모보다 C. utilis, K. fragilis가 높은 생존율과 성장을 보였으며 세포벽을 제거한 것이 제거하지 않은 것보다 유의적으로 높은 생존율을 보였다. Artemia의 생존율은 75%와 50% 세포벽을 제거한 것이 25%에 비해 유의적으로 높은 생존율을 보였다. 성장은 유의적이지는 않지만 전체적으로 세포벽을 많이 제거할수록 성장과 생존율은 높은 경향이었다. 이와같이 Artemia의 경우는 세포벽을 제거한 C. utilis가 더 좋은 먹이효율을 보인 것은 Artemia는 효모의 세포벽을 소화시키지 못하기 때문으로 판단 할 수 있다. 진주담치 유생의 먹이로 C. utilis를 공급한 경우 성장에 있어서 세포벽을 제거한 효모를 50% 대체한 실험구의 먹이효율이 가장 좋았으며 세포벽을 벗기지 않은 효모의 경우 I. galbana에 비해 낮은 결과를 보였다. 진주담치 유생에 있어서도 세포벽을 제거한 C. utilis를 공급한 것은 대조구인 I. galbana와 생존율에 있어 유의성이 없었다. 그리고 25% 세포벽을 제거한 것을 공급한 실험구는 유의적으로 낮은 생존율을 보였다. 각장 성장의 경우 75% 세포벽을 제거한 것은 대조구인 I. galbana와 유의성이 없었다. 세포벽을 제거한 C. utilis와 I. galbana를 1:1로 혼합하여 공급한 실험의 경우 생존율에 있어서는 세포벽을 50%, 75% 제거한 C. utilis를 50% 첨가한 실험구는 대조구인 I. galbana 100%를 공급한 것과 유의적인 차이가 없었다. 그러나 성장의 경우는 I. galbana 에 세모벽을 75% 제거한 C. utilis를 1:1로 혼합한 실험구에서 각장 179.3 $\mu\textrm{m}$, 각고 150.3 $\mu\textrm{m}$로 가장 높았고 대조구인 I. galbana 100%와는 유의적인 차이를 보였다.

• Journal of the Korean Chemical Society
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• v.38 no.1
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• pp.74-79
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• 1994

The participation of superoxide in initiating tissue damage derived from xenobiotics is best illustrated by paraquat intoxication. In the present study, the roles of superoxide dismutase and catalase on paraquat-induced cell injury were investigated using primary cultured rat skin fibroblast. The degree of cell injury was assassed by the conversion of reduced MTT to a blue formazan. Paraquat produced concentration-and time-related cell injury in cultured rat skin fibroblast. Paraquat induced-cell injury was aggravated by pretreatment of aminotriazol (AT: 10 mM), an catalase inhibitor, and attenuated by addition of catalase (100∼500 unit/ml). However, the effects of diethyldithiocarbamate (DDC : 10 mM), copper- and zinc-containing superoxide dismutase (Cu, Zn-SOD) inhibitor, and Cu, Zn-SOD on paraquat-induced injury were not significant. These results suggest that hydrogen peroxide might be more responsible factor than superoxide in the pathogenesis of paraquat-induced cell injury.

• Journal of The Korean Ophthalmological Society
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• v.59 no.11
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• pp.1056-1061
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• 2018

Purpose: To investigate the effects of valproic acid on the survival of cultured human Tenon's capsule fibroblasts (HTFBs). Methods: Primary cultured HTFBs were exposed to 0, 0.25, 0.5, and 1.0 mM valproic acid with or without 0, 1.0, $2.5{\mu}g/mL$ mitomycin C, and incubated for 5 days. Cell survival was assessed using an MTT (3-[4, 5-dimethylthiazol-2-yl]-2, 5-diphenyltetrazolium bromide) assay and the degree of apoptosis was assessed by flow cytometry using annexin-V/propidium iodide double staining. Results: Valproic acid decreased the survival of HTFBs in a dose-dependent manner, and survival was further decreased by adding mitomycin C to valproic acid. Both valproic acid and mitomycin C induced apoptosis of HTFBs. Valproic acid induced less apoptosis than mitomycin C. Conclusions: Valproic acid decreased the cellular survival of HTFBs and induced apoptosis. The antiproliferative effects of valproic acid were further enhanced by the addition of mitomycin C.

• Journal of Chest Surgery
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• v.34 no.4
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• pp.305-310
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• 2001

배경: 판막대치술에 냉동보존판막의 이용은 감염에 대한 저항성과 탁월한 혈류역학으로 증가하고 있다. 판막육아세포의 생존율은 이식된 냉동보존 판막의 내구성에 영향을 미친다고 알려져 있고, 세포의 생존율은 warm ischemic time에 영향을 받는 것으로 알려져 있다. 냉동 보존하여 이식할수 있는 공여 판막의 warm ischemic time 의 적정치를 구하기 위하여, warm ischemic time에 다른 세포의 생존율을 관찰하였다. 대상 및 방법: 1.조직의 획득: 실제 판막을 냉동 보존하는 상황과 유사하게 하기 위하여 도살된 돼지의 심장과 폐를 밀봉한 상태로 4~8$^{\circ}C$로 냉장 보관하여 (warm ischemic time) 일정시간이 경과한 후, 심장과 폐에서 심장을 적출하여 4$^{\circ}C$하트만 용액에 24시간 보관하였다.(cold ischemic time). Warm ischemic time에 따라 2시간, 12시간, 24시간 36시간으로 4군으로 나누었으며, 각 군마다8개의 돼지 심자을 이용하였다. 2. 조직의 멸균: RRMI 1640에 항생제를 섞은 용액에 멸균하고, 3 냉동과 냉동보존; American tissue bank에서 제시한 냉동곡선에 따라 냉동하여, 액체질소 탱그에서 7일간 보존 후 해동하였다. 4. 생존율의 측정; 판막의 생존율 검사는 Triphan blue test로 하였고, 각각 warm ischemic period후 , cold ischemic period 후, 해동 후에 시행하였다. 5. 분석방법; 분석은 SAS program의 pearson correlation으로 하였다. 결과: 1. 멸균, 냉동과 냉동 보존하는 과정의 적합성을 규명하기 위하여 이 과정의 전과 후인 Cold ischemic period 후와 해동 후의 대동맥판막의 생존율의 차이를 비교한 결과, 차이가 없었다.(p =0.619). 2, warm ischemic time 과 warm ischemic period 후 , Cole ischemic period 후와 해동후의 대동맥판막의 생존율과의 correlation 은 각각 R= -0.857, -.0.673과 -0.549로 강하거나 , 혹은 뚜렷한 음성적 관계가 있었다. 삼천판막의 생존율과 대동맥판막의 생존율과 뚜렷한 상관관계가 있었다. 결론; 1. Warm ischemic time 이 길어지면 판막유아세포의 생존율이 감소하고, 12시간 이상되면 해동후의 판막육 아페포의 생존율이 50% 이하로 떨어졌다. 2. 본 연구에서 시행한 판막의 냉동보존방법은 세포의 생존율을 유지하는데 양호한 것으로 나타났으며 삼천판막으로 대동맥판막의 생존율을 예측해 볼 수 있다. 3. 그러나, 이식후 장기간 적절한 내구성을 갖기 위한 이식될 판막의 생존율은, 육아세포에 관한 여구가 좀 더 되어야 규명될 것이다.

• Journal of the Korean Society of Radiology
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• v.6 no.6
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• pp.507-513
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• 2012

This research was performed to evaluate the superparamagnetic iron oxide nanoparticles'(SPIONs) cell toxicity and to measure the radiation cell survival curve changes of SPIONs-uptake glioblastoma multiforme cells. The results could be practically used as the fundamental data to ameliorate proton beam cancer therapy, for example, providing necessary GBM treatment dose in the proton beam therapy when the therapy takes advantage of SPIONs. The assessment of the toxicological evaluation of synthesized SPIONs was accomplished by MTT assay as an in vitro experiment. The results showed no meaningful differences in the cell survival rate at the $1-100{\mu}g/ml$ SPIONs concentrations, but the cell toxicity was shown as the cell survival rate decreased up to 74.2% at the $200{\mu}g/ml$ SPIONs concentration. Then, we measured each radiation cell survival curve for U373MG cells and SPIONs-uptake U373MG cells with 0~5 Gy of proton beam irradiations. It is learned from the analysis of the experimental results that the SPION-uptake cells' radiation survival rate was more rapidly decreased as the irradiation dose increased. In conclusion we confirmed that SPIONs-uptake in U373MG cells induces cell death at the much less dose than the lethal dose of SPION-non-uptake cell. This research shows that the therapeutic efficacy of glioblastoma multiforme treatment in proton beam therapy can be improved by SPIONs targeting to the GBM cells.

• Journal of Animal Science and Technology
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• v.48 no.5
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• pp.719-726
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• 2006

Bovine whey protein are rich in cysteine, which is the rate limiting amino acid for synthesis of antioxidant glutathione(GSH). Some strains of Lactobacillus caseihas been reported to contain high level of GSH in cell extracts. The objective ofthis study was to determine whether enzymatically hydrolyzed whey protein isolate(WPI) and cell extract of Lb. casei HY2782 could increase intracellular GSH concentrations and protect against oxidant induced cell death in human prostate epithelial cell line (designated as RWPE1, and PC3MMM2 cells). Treatment of RWPE1 cellsandPC3MMM2 cells with hydrolyzed WPI (500g/ml) significantly increased GSH by28.2% and38.4% respectively. Compared with control cells receiving no hydrolyzed WPI(P<0.05). hydrolyzed WPI and Lb casei HY2782 cell extracts significantly protected RWPE1 and PC3MMM2 cellsfrom oxidant induced cell death compared with controls receiving no WPI. DNA damage associated with oxidant treatment was demonstrated by single cell gel (SCG) electrophoresis.

• Progress in Medical Physics
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• v.11 no.2
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• pp.157-165
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• 2000

Purpose: For estimation of yields of l)NA damages induced by radiation and enhanced by oxygen, a mathematical model was used and tested. Materials and Methods: Reactions of the products of water radiolysis were modeled as an ordinary time dependant equations. These reactions include formation of radicals, DNA damage, damage repair, restitution, and damage fixation by oxygen and H-radical. Several rate constants were obtained from literature while others were calculated by fitting an experimental data. Sensitivity studies were performed changing the chemical rate constant at a constant oxygen number density and varying the oxygen concentration. The effects of oxygen concentration as well as the damage fixation mechanism by oxygen were investigated. Oxygen enhancement ratio(OER) was calculated to compare the simulated data with experimental data. Results: Sensitivity studies with oxygen showed that DNA survival was a function of both oxygen concentration and the magnitude of chemical rate constants. There were no change in survival fraction as a function of dose while the oxygen concentration change from 0 to 1.0 x 10$^{7}$ . When the oxygen concentration change from 1.0 $\times$ 107 to 1.0 $\times$ 101o, there was significant decrease in cell survival. The OER values obtained from the simulation study were 2.32 at 10% cell survival level and 1.9 at 45% cell survival level. Conclusion: Sensitivity studies with oxygen demonstrated that the experimental data were reproduced with the effects being enhanced for the cases where the oxygen rate constants are largest and the oxygen concentration is increased. OER values obtained from the simulation study showed good agreement for a low level of cell survival. This indicated that the use of the semi-empirical model could predict the effect of oxygen in cell killing.

• Journal of radiological science and technology
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• v.37 no.1
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• pp.21-28
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• 2014

Cultured pancreatic beta cells and nerve cells, it is given normal condition of 10% FBS (fetal bovine serum), 11.1 mM glucose and hyperglycemia codition of 1% FBS, 30 mM glucose. For low LET X-ray irradiated with 0.5 Gy/hr dose-rate(total dose: 0.5 to 5 Gy). Survival rates were measured by MTT assay. When non irradiated, differentiated in the pancreatic beta cells experiment is hyperglycemia conditions survival rate compared to normal conditions survival rate seemed a small reduction. However increasing the total dose of X-ray, the survival rate of normal conditions decreased slightly compared to the survival rate of hyperglycemia conditions, the synergistic effect was drastically reduced. When non irradiated, undifferentiated in the nerve cells experiment is hyperglycemia conditions survival rate compared to normal conditions survival rate seemed a large reduction. As the cumulative dose of X-ray normal conditions and hyperglycemia were all relatively rapid cell death. But the rate of decreased survivals by almost parallel to the reduction proceed and it didn't show synergistic effect.