• 치위생과학회지
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• 제7권1호
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• pp.21-24
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• 2007

본 실험에서는 S. mutans KCTC 3065을 이용하여 lactic acid를 첨가하였을 때 일어나는 스트레스 반응을 살펴보고자 하였으며 다음과 같은 결론을 얻었다. 1. 배지에 lactic acid를 농도별로 첨가하여 농도에 따른 생육저해현상을 조사한 결과, 배 지에 첨가 된 lactic acid의 함량에 비례하여 S. mutans의 성장이 완만해지며, 지수증식기일 때 lactic acid를 첨가 하였을 경우 유도기일 때 lactic acid를 첨가한 경우보다 균의 성장이 활발한 것을 알 수 있었다. 2. 대수증식기의 균주를 취하여 0, 60, 70, 80 mM 농도의 lactic acid를 처리한 후 colony의 생성으로 균주의 생존유무를 관찰한 결과, 70 mM의 농도로 lactic acid를 처 리하고 90분후부터는 colony의 밀도가 급격히 낮아지며생존에 영향을 받는 것을 관찰할 수 있었으며, lactic acid의 농도가 80 mM이상 에서는 생존이 거의 불가능한 것으로 나타났다. 3. Acid stress 동안에 지방산 조성의 변화를 관찰한 결과, $C_{18:1}$은 30.92%에서 33.89%로 증가하였으며 $C_{14:0}$은 5.02%에서 2.62%로 $C_{16:0}$은 39.16%에서 33.69%로 감소하였다. 4. Acid stress 동안에 단백질 패턴의 변화를 관찰한 결과, 약 70 kDa, 60 kDa, 45 kDa, 40 kDa 그리고 23 kDa의 단 백질 발현이 증가되는 것을 볼 수 있었다.

• Asian-Australasian Journal of Animal Sciences
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• 제23권7호
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• pp.880-888
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• 2010

The ameliorative effect of salts and ascorbic acid polyphosphate supplementation on heat stress was studied in buffaloes. Adult buffaloes of either sex were randomly divided into 2 groups of 4 animals each. Group I served as control and Group II was supplemented with sodium bicarbonate, potassium carbonate and ascorbic acid polyphosphate. All the animals were exposed to two conditions of temperature and humidity: hot-dry and hot-humid in a psychrometric chamber for 4 h daily for 10 days. Blood was collected on day 1, 5 and 10 of treatment. The activities of catalase and superoxide dismutase (SOD), concentrations of serum glutathione (GSH), cortisol, sodium, potassium, and chloride and lipid peroxidation were estimated in serum. Lymphocyte proliferation was assessed in blood. The activities of catalase and SOD, serum concentration of GSH, sodium, potassium and chloride decreased while lipid peroxidation and serum cortisol increased in both groups when subjected to heat stress. Dietary supplementation resulted in further decreasing of the enzyme activities but increasing of the serum concentrations of GSH, sodium, potassium and chloride. Lipid peroxidation and serum cortisol increased in the supplemented group in both types of stress. Dietary supplementation caused an increase in lymphoproliferative response to con A. Thus, supplementation of ascorbate in addition to electrolytes relieves the animals of oxidative stress and boosts cell mediated immunity.

• Journal of Crop Science and Biotechnology
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• 제10권1호
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• pp.39-44
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• 2007

The effect of inabenfide was investigated in rice seedlings subjected to salt stress in relation to changes in chlorophyll fluorescence(${\Delta}F/Fm'$), lipid peroxidation, salicylic acid(SA) content, and catalase(CAT) activity. A reduction in shoot growth of rice seedlings by 120 mM NaCl treatment was significantly alleviated by pretreatment with 30 ${\mu}M$ inabenfide. Sodium ion content was not affected by pretreatment with inabenfide, suggesting that alleviation was not due to a reduction in sodium ion uptake by the rice seedlings. At three days after NaCl treatment, the rice seedlings pretreated with inabenfide showed a higher ${\Delta}F/Fm'$(30%) and lower lipid peroxidation(28%) compared with the rice seedlings treated with NaCl alone. After NaCl treatment, CAT activity in the third leaf of rice seedlings decreased significantly but alleviated by pretreatment with inabenfide. Furthermore, pretreatment with inabenfide also reduced the level of SA which accumulated drastically in the third leaf of rice seedlings within a day after exposure to salt stress. These results suggest that inabenfide prevents SA accumulation in rice seedlings under salt stress which eventually induces the alleviation of salt stress damage.

• 한국작물학회지
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• 제59권1호
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• pp.54-58
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• 2014

물 자원이 제한되거나 관수 설비가 갖추어지지 않은 곳에서 찰옥수수의 한발 피해를 줄이고자, 종실용 옥수수에 대한 수분 스트레스 경감 효과가 보고되어진 살리실산과 앱시식산의 처리 효과를 살펴보았다. 출웅기 9일 전부터 출웅 후 14일까지 관수를 중단하였으며, 생장조절제는 출웅기에 1회 처리하였다. 살리실산과 앱시식산의 처리 농도는 각각 0.5 mM과 0.1 mM이었다. 한발 처리에 의해 ASI가 3.0~3.3일 늘어났으며, 간장은 47~51 cm, 이삭장은 4.6~5.0 cm, 이삭경은 4.4~5.3 mm, 열수는 1.5~2.0개, 수량은 2.4~2.5 Mg/ha 줄었다. 살리실산과 앱시식산의 처리에 의한 한발 피해의 경감 효과는 뚜렷하지 않았다. 찰옥수수에 대한 살리실산과 앱시식산의 한해 경감 효과를 위해서는 수분 부족 스트레스를 받기 이전에 처리하거나, 저농도로 몇차례에 나누어 처리하는 것이 필요한 지에 대한 추후 검토가 필요하다.

• Biomolecules & Therapeutics
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• 제24권3호
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• pp.338-345
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• 2016

Neurodegenerative diseases are often associated with oxidative damage in neuronal cells. This study was conducted to investigate the neuro-protective effect of methanolic (MeOH) extract of Perilla frutescens var. japonica and its one of the major compounds, rosmarinic acid, under oxidative stress induced by hydrogen peroxide ($H_2O_2$) in C6 glial cells. Exposure of C6 glial cells to $H_2O_2$ enhanced oxidative damage as measured by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide and thiobarbituric acid-reactive substance assays. The MeOH extract and rosmarinic acid prevented oxidative stress by increasing cell viability and inhibiting cellular lipid peroxidation. In addition, the MeOH extract and rosmarinic acid reduced $H_2O_2-indcued$ expression of inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2) at the transcriptional level. Moreover, iNOS and COX-2 protein expression was down-regulated in $H_2O_2-indcued$ C6 glial cells treated with the MeOH extract and rosmarinic acid. These findings suggest that P. frutescens var. japonica and rosmarinic acid could prevent the progression of neurodegenerative diseases through attenuation of neuronal oxidative stress.

• 대한의생명과학회지
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• 제13권4호
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• pp.341-347
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• 2007

Streptococcus mutans, one of a major causal agents of dental caries, is component of the dental plaque and produces various organic acids such as lactic acid as the end-product of glycolysis. In this study, we isolated S. mutans from Korean children with caries and also investigated the expression of protein under acid stress. S. mutans was identified at the species level using a 16S ribosomal DNA sequencing comparison method. The primer specificity was tested on eleven S. mutans strains isolated from Korean children with caries. The data showed that eleven strains are S. mutans. At treatment of concentration of 20 mM lactic acid in the mid-log phage, K-7 exhibited the highest maximum culture OD compared with those of other groups. As a consequence, we examined the expression of protein under 20 mM lactic acid stress using S. mutans K-7. The results of 2D gel electrophoresis by image analysis showed that thirteen proteins are up-regulated under the stress. Further study is being focused on amino acid analysis by mass spectrometry in order to analyze those spots.

• 한국토양비료학회지
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• 제48권3호
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• pp.213-217
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• 2015

Soil moisture shortage can reduce yield of waxy corn because maize is one of the sensitive crops to the drought stress. Farmers cannot irrigate due to limited water resource and irrigating facilities although applying water is the most effective practice to solve the drought problem. The study was conducted to investigate the pre-treatment effect of salicylic acid on reducing drought damage of waxy corn (Zea mays L.). Salicylic acid at concentration of 0.2 mM was applied at seven-leaf stage or ten-leaf stage three times. Drought stress was imposed by withholding irrigation from 11 days before anthesis to 10 days after anthesis. Application of salicylic acid significantly increased ear length by 11.0~12.3% and yield by 8.8~11.3% compared with non-treated control, indicating that the drought injuries of waxy corn can be alleviated through pre-treatment of salicylic acid at the vegetative stage.

• Preventive Nutrition and Food Science
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• 제17권2호
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• pp.158-165
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• 2012

This study was designed to investigate whether the fatty acid composition could make a significant contribution to the oxidation stability of vegetable oils marketed in Korea. Ten kinds, 97 items of vegetable oils that were produced in either an industrialized or a traditional way were collected and analyzed for their fatty acid compositions and lipid oxidation products, in the absence or presence of oxidative stress. Peroxidability index (PI) calculations based on the fatty acid composition ranged from 7.10 to 111.87 with the lowest value found in olive oils and the highest in perilla oils. In the absence of induced oxidative stress, malondialdehyde (MDA), the secondary lipid oxidation product, was generated more in the oils with higher PI (r=0.890), while the tendency was not observed when the oils were subjected to an oxidation-accelerating system. In the presence of the oxidative stress, the perilla oils produced in an industrialized manner generated appreciably higher amounts of MDA than those produced in a traditional way, although both types of oils presented similar PIs. The results implicate that the fatty acid compositions could be a predictor for the oxidation stability of the vegetable oils at the early stage of oil oxidation, but not for those at a later stage of oxidation.

• BMB Reports
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• 제31권2호
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• pp.201-208
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• 1998

Amino acid analogs, like other inducers of stress response, induce the synthesis of stress proteins in mammalian cells. In this study, Drosophila Kc cells, in which translation is tightly controlled during stress response, was treated with proline analogs, L-azetidine-2-carboxylic acid (AzC) and 3,4-dehydro-L-proline (dh-P). Kc cells exposed to AzC or dh-P induced the synthesis of several proteins which had the same molecular weights as known heat shock proteins. However, in Kc cells, normal protein synthesis still continued in the presence of amino acids analogs unlike in heat-shocked cells. For the induction of stress response, the incorporation of dh-P into the protein was not essential, but the incorporation of AzC was. The stress protein synthesis was regulated mainly at the transcriptional level by AzC, whereas it was regulated by dh-P at the transcription level and possibly posttranscription level. During recovery, the stress protein synthesis stopped sooner in analog-treated cells than in heat-shocked cells even though the accumulated amount of Hsp70 was much less in proline analogstreated cells. It could be concluded that the proline analogs, AzC and dh-P, induced stress response through a different mechanism from heat shock.

• 한국생명과학회:학술대회논문집
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• 한국생명과학회 2008년도 제49회 학술심포지움 및 국제학술대회
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• pp.90.1-90.1
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• 2008