• 제목/요약/키워드: Sun:activity

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Cystocin, a Novel Antibiotic, Produced by Streptomyces sp. GCA0001: Biological Activities

  • Lee, Hei-Chan;Liou, Kwangkyoung;Kim, Dae-Hee;Kang, Sun-Yub;Woo, Jin-Suk;Sohng, Jae-Kyung
    • Archives of Pharmacal Research
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    • 제26권6호
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    • pp.446-448
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    • 2003
  • Cystocin belongs to the class of nucleoside antibiotics from Streptomyces sp. GCA0001. Cystocin showed good activity against Gram-positive bacteria, but showed less activity against the Gram-negative bacteria. Cystocin exhibited about two to four folds higher activity than puromycin. Especially, cystocin shows relatively strong activity against Streptococcus strains. Cystocin shows quite potent antitumor activity against all of the cells tested showing $IC_{50}$ values of 0.10 to 0.14 $\mu$ g/mL. This in vitro result indicates that the cytotoxocity of cystocin is two ten folds more active than puromycin s.

In vitro inhibition of 10-formyltetrahydrofolate dehydrogenase activity by acetaldehyde

  • Mun, Ju-Ae;Doh, Eun-Jin;Min, Hye-Sun
    • Nutrition Research and Practice
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    • 제2권4호
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    • pp.195-199
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    • 2008
  • Alcoholism has been associated with folate deficiency in humans and laboratory animals. Previous study showed that ethanol feeding reduces the dehydrogenase and hydrolase activity of 10-formyltetrahydrofolate dehydrogenase (FDH) in rat liver. Hepatic ethanol metabolism generates acetaldehyde and acetate. The mechanisms by which ethanol and its metabolites produce toxicity within the liver cells are unknown. We purified FDH from rat liver and investigated the effect of ethanol, acetaldehyde and acetate on the enzyme in vitro. Hepatic FDH activity was not reduced by ethanol or acetate directly. However, acetaldehyde was observed to reduce the dehydrogenase activity of FDH in a dose- and time-dependent manner with an apparent $IC_{50}$ of 4 mM, while the hydrolase activity of FDH was not affected by acetaldehyde in vitro. These results suggest that the inhibition of hepatic FDH dehydrogenase activity induced by acetadehyde may play a role in ethanol toxicity.

Rearch of Late Adolcent Activity based on Using Big Data Analysis

  • Hye-Sun, Lee
    • International Journal of Advanced Culture Technology
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    • 제10권4호
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    • pp.361-368
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    • 2022
  • This study seeks to determine the research trend of late adolescents by utilizing big data. Also, seek for research trends related to activity participation, treatment, and mediation to provide academic implications. For this process, gathered 1.000 academic papers and used TF-IDF analysis method, and the topic modeling based on co-occurrence word network analysis method LDA (Latent Dirichlet Allocation) to analyze. In conclusion this study conducted analysis of activity participation, treatment, and mediation of late adolescents by TF-IDF analysis method, co-occurrence word network analysis method, and topic modeling analysis based on LDA(Latent Dirichlet Allocation). The results were proposed through visualization, and carries significance as this study analyzed activity, treatment, mediation factors of late adolescents, and provides new analysis methods to figure out the basic materials of activity participation trends, treatment, and mediation of late adolescents.

지유 추출물 및 분획물의 항산화 활성과 식중독 원인균에 대한 항균활성 (Antioxidant Activity and Antimicrobial Effect for Foodborne Pathogens from Extract and Fractions of Sanguisorba officinalis L.)

  • 서고은;김선민;표병식;양선아
    • 한국약용작물학회지
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    • 제24권4호
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    • pp.303-308
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    • 2016
  • Background: This study aimed to investigate the antioxidat and antimicrobial activities of the methanol extract and its fractions prepared from the roots of Sanguisorba officinalis L. Methods and Results: The antioxidant activities were compared by evaluating the DPPH radical and nitric oxide (NO) scavenging ability. Measurement of DPPH radical scavenging ability showed that the $SC_{50}$ values of the ethyl acetate fraction was $3.85{\mu}g/m{\ell}$. The ethyl acetate fraction exhibited the most effective DPPH radical scavenging ability compared with the other samples. As for the NO scavenging ability, at all tested concentrations, the ethyl acetate fraction showed a higher scavenging activity than that of the extract and other fractions. These results are related to the total phenolic compound and flavonoid contents of the ethyl acetate fraction. Antimicrobial activity against foodborne pathogens was investigated using the disc diffusion assay. The ethyl acetate fraction showed the highest antimicrobial activity against gram-positive Staphylococcus aureus and Bacillus cereus. However, the chloroform fraction had a higher antimicrobial activity against gram-negative Vibrio vulnificus than that of the extract and other fractions. Conclusions: The results show that the ethyl acetate fraction had a higher antioxidant as well as antimicrobial activity, than did the other samples. Therefore, the ethyl acetate fraction has potential application in the food industry.

양제근 추출물 및 분획의 항산화 활성과 Tyrosinase 저해 활성 (Antioxidant and Tyrosinase Inhibitory Activity of Extract Rumex japonicus HOUTT Root and Its Fractions)

  • 양선아;서고은;표병식;김선민;최철희
    • 한국약용작물학회지
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    • 제25권1호
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    • pp.10-15
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    • 2017
  • Background: We investigated the antioxidative and tyrosinase inhibitory activities of 70% ethanol extract, and its fractions, of the root of Rumex japonicus HOUTT. Methods and Results: The total phenolic compound contents of the 70% ethanol extract and ethyl acetate fraction were 168.99 mg/g and 651.78 mg/g, respectively. The antioxidant activity was compared through the DPPH radical and nitric oxide (NO) scavenging assays. The ethyl acetate fraction showed the highest DPPH radical and NO scavenging abilities, which confirmed the antioxidant activity. Specifically, the ethyl acetate fraction showed a higher DPPH radical scavenging ability than ascorbic acid. These results were related to the total phenolic compound content of the ethyl acetate fraction. Moreover, in the tyrosinase inhibition assay, the ethyl acetate fraction exhibited stronger inhibitory activity than arbutin, which was used as the positive control. The cell viability of L929 cells was analyzed by MTT assay after treatment with 70% ethanol extract and all fractions; no changes in viability were observed, which demonstrated the nontoxic nature of the extract and fractions. Conclusions: These results suggested that the extract from the root of R. japonicus and its ethyl acetate fraction could be a novel resource for the development of a cosmetic with antioxidant and tyrosinase inhibitory activity.

The Effects of Donepezil, an Acetylcholinesterase Inhibitor, on Impaired Learning and Memory in Rodents

  • Shin, Chang Yell;Kim, Hae-Sun;Cha, Kwang-Ho;Won, Dong Han;Lee, Ji-Yun;Jang, Sun Woo;Sohn, Uy Dong
    • Biomolecules & Therapeutics
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    • 제26권3호
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    • pp.274-281
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    • 2018
  • A previous study in humans demonstrated the sustained inhibitory effects of donepezil on acetylcholinesterase (AChE) activity; however, the effective concentration of donepezil in humans and animals is unclear. This study aimed to characterize the effective concentration of donepezil on AChE inhibition and impaired learning and memory in rodents. A pharmacokinetic study of donepezil showed a mean peak plasma concentration of donepezil after oral treatment (3 and 10 mg/kg) of approximately $1.2{\pm}0.4h$ and $1.4{\pm}0.5h$, respectively; absolute bioavailability was calculated as 3.6%. Further, AChE activity was inhibited by increasing plasma concentrations of donepezil, and a maximum inhibition of $31.5{\pm}5.7%$ was observed after donepezil treatment in hairless rats. Plasma AChE activity was negatively correlated with plasma donepezil concentration. The pharmacological effects of donepezil are dependent upon its concentration and AChE activity; therefore, we assessed the effects of donepezil on learning and memory using a Y-maze in mice. Donepezil treatment (3 mg/kg) significantly prevented the progression of scopolamine-induced memory impairment in mice. As the concentration of donepezil in the brain increased, the recovery of spontaneous alternations also improved; maximal improvement was observed at $46.5{\pm}3.5ng/g$ in the brain. In conclusion, our findings suggest that the AChE inhibitory activity and pharmacological effects of donepezil can be predicted by the concentration of donepezil. Further, $46.5{\pm}3.5ng/g$ donepezil is an efficacious target concentration in the brain for treating learning and memory impairment in rodents.

Enhancement of a Liver Form of Cytosolic Phospholipase $A_2$ Activity by Methylmercury

  • Huh, Don-Haeng;Kang, Mi-Sun;Sohn, Dong-Hun;Na, Doe-Sun;Kim, Dae-Kyong
    • BMB Reports
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    • 제31권2호
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    • pp.189-195
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    • 1998
  • Methylmercury (MeHg), which is widely distributed in the environment, is well known for both its acute and chronic poisoning effects on the human health; however, the precise biochemical mechanisms by which this compound elicits its toxicity in a cellular level are still poorly understood. To examine whether MeHg-induced liver injury involves activation of Phospholipase $A_2$ ($PLA_2$), the $PLA_2$ activity of control and MeHg-administrated livers was measured. MeHg stably enhanced a liver form of cytosolic $PLA_2$ activity, which exhibited several biochemical properties similar to those of the 100 kDa $cPLA_2$, except in its elution profile of a DEAE-5PW HPLC, and it migrated as a molecular weight of 80 kDa in Western blot analysis. This blotting analysis also indicated that the MeHg-induced enhancement of the activity could be due to the increase in the amount of the enzyme protein rather than a stable modification of the enzyme such as phosphorylation. Our data also showed the higher myeloperoxidase activity in MeHg-administrated liver than in the control, suggesting that this increase in the amounts of the 80 kDa $PLA_2$ and its activity may be resulted from infiltration of neutrophils into the liver during a hepatic injury process such as MeHg-induced inflammation. Taken together, these data suggest that MeHg-induced liver injury may be mediated by activation of the 80 kDa form of liver cytosolic $PLA_2$.

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운동군과 비운동군 고등학생의 활동량, 활동계수, 예측 휴식대사량, 1일 에너지 및 영양소 섭취량의 비교 (Comparison of Activity Factor, Predicted Resting Metabolic Rate, and Intakes of Energy and Nutrients Between Athletic and Non-Athletic High School Students)

  • 김은경;김귀선;박지선
    • 대한영양사협회학술지
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    • 제15권1호
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    • pp.52-68
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    • 2009
  • This study compared activity factor. predicted resting metabolic rate (RMR), and nutrient intakes between athletic and non-athletic high school students in Gangwon-do. Fifty soccer players (30 males and 20 females; mean ages 16.7${\pm}$1.0 years and 16.4${\pm}$1.1 years. respectively) and 50 non-athletic (30 males and 20 females: mean ages 17.5${\pm}$0.4 years and 16.4${\pm}$1.1 years respectively) high school students were included. Anthropometric measurements included: weight and height. triceps skinfold, mid-ann circumference, and body fat. Prediction equations consisted of those from the Harris-Benedict. FAO/WHO/VNU, IMNA, Cunningham, Mifflin et al., and Owen et al. A one-day activity diary was collected by interview, and the 24-hour recall method was used to analyze nutrient intakes of subjects. The activity factors of the male and female athletic groups (2.23 and 2.16, respectively) were significantly higher than those (1.52 and 1.46, respectively) of the non-athletic group. There was only a significant difference in RMR by use of the Cunningham's equation between two groups. For the males. almost all nutrient intakes of the athletic group (except carbohydrate, iron, vitamin $B_1$, $B_6$, and niacin) of athletic group were significantly higher than those of the non-athletic group. The female athletic group showed significantly higher nutrient intakes with the exception of most vitamins. These results suggest that assessments of energy balance between energy intake and energy expenditure by employing RMR and activity factors would be useful to prevent and treat obesity in high school athletes. In addition, the Cunningham's equation would be appropriate for predicting their energy needs.

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태양활동과 우주환경 (SOLAR ACTIVITY AND SPACE ENVIRONMENT)

  • 윤홍식
    • 천문학논총
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    • 제14권2호
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    • pp.83-89
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    • 1999
  • The Earth is exposed to constant outflow of the solar wind from the outer layers of the Sun, and violent transient events taking place from active regions increase the energy flux of both radiation and particles leaving the Sun. Thus the space surrounding the Earth is a highly dynamic environment that responds sensitively to changes in radiation, particles and magnetic field arriving from the Sun. Nowadays, it becomes increasingly important to understand how the physical system of Earth-space works and how the space around the Earth connects to interplanetary space. In the present paper we describe how explosive solar events, such as CME(Coronal Mass Ejection) and flares affect the Earth-space environment and how the space weather reacts to them. Practical consequences are presented to demonstrate why a broader view of Earth's environment is greatly needed to cope with modern day's inhabitation problem in a rapidly developing space age.

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한국인에서 비만에 따른 신체활동와 치주질환과의 연관성 (Association between physical activity and periodontitis as stratified by obesity in Koreans)

  • 김미선;신혜선
    • 대한치위생과학회지
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    • 제6권1호
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    • pp.65-76
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    • 2023
  • 연구의 배경 및 목적: 본 연구의 목적은 한국인에서 신체활동과 치주염 사이의 연관성을 조사하는 것이다. 연구방법: 국민건강영양조사 2012년과 2013년 자료를 활용하여 우리나라 성인 9,191명에 대해 분석하였다. 치주 상태 조사는 지역사회치주요양필요지수(Community Periodontal Index, CPI)를 이용하여 CPI 3과 4를 치주염으로 정의하였다. 신체활동은 단축형 국제신체활동설문(International Physical Activity Questionnaire-Short Form, IPAQ-SF)을 이용하여 걷기 활동, 중등도 활동, 격렬한 활동으로 분류하여 분석하였다. 주요 변수간의 연관성은 로지스틱 회귀분석을 적용하였고, 비만 변수에 대해 층화분석을 적용하였다. 모든 분석은 성별에 따른 신체활동 수준의 차이가 있으므로 남녀를 나누어 분석하였다. 결과: 남성에서 치주염 유병률은 33.9%, 여성에서 치주염 유병률은 22.2%였다. 격렬한 신체활동과 중등도 신체활동을 하는 여성그룹에서 치주염 유병률이 각각 28% (OR=0.72, 95% CI=0.54-0.95), 34% ((OR=0.66, 95% CI=0.44-0.98) 낮았다. 반면 남성에서는 유의한 연관성을 보이지 않았다. 비만인 여성그룹에서는 중등도 활동을 한 그룹에서 65% (OR=0.35, 95% CI=0.18-0.67)의 더 높은 신체활동 감소와 연관성이 있었다. 결론: 본 연구조사 결과 중등도 신체활동은 치주염과 음의 연관성(inverse association)이 있다는 것을 보여주었다. 비만 여성에서는 중등도 신체활동이 치주염과 독립적으로 연관성이 있고 비만 변수가 효과변경인자(effect modifier)가 된다는 것을 확인하였다.