• Title/Summary/Keyword: Biological mechanism

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Mechanism for Antioxidant Activity of Nardostachys chinensis root Extract

  • Heo, Jee-In;Kim, Jeong-Hyeon;Lee, Jeong-Min;Kim, Sung Chan;Park, Jae-Bong;Kim, Jaebong;Lee, Jae-Yong
    • Journal of Applied Biological Chemistry
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    • v.57 no.1
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    • pp.17-22
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    • 2014
  • Nardostachys chinensis (N. chinensis) has been used in traditional medicine as a sedative and analgesic. It has been reported that N. chinensis extract has an antioxidant activity. However, the mechanism has not been elucidated. In this study, we showed that FOXO3a was activated by N. chinensis extract. FOXO3a is a transcriptional factor that involved in cell cycle arrest, DNA repair, apoptosis, and detoxification of reactive oxygen spices (ROS). Protein level of FOXO3a was increased by N. chinensis extract whereas phospho-FOXO3a (Thr 32) was not changed. Promoter activities of target genes of FOXO3a such as MnSOD, p27, and GADD45 were increased by N. chinensis extract. Among target genes, protein level of MnSOD was increased by N. chinensis extract, and this leads to removal of ROS level in human embryonic fibroblast (HEF) cells. These results suggested that N. chinensis extract has an antioxidant activity by upregulation of MnSOD through FOXO3a activation.

Young Chilldren's Causal Reasoning on Psychology and Biology : Focusing on the Interaction between Domain-specificty and Domain-generality (심리와 생물 영역에서의 유아의 인과추론 : 영역특정성과 영역일반성의 상호작용)

  • Kim, Ji-Hyun
    • Journal of Families and Better Life
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    • v.26 no.5
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    • pp.333-354
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    • 2008
  • This study aimed to investigate the role of domain-specific causal mechanism information and domain-general conditional probability in young children's causal reasoning on psychology and biology. Participants were 121 3-year-olds and 121 4-year-olds recruited from seven childcare centers in Seoul, Kyonggi Province, and Busan. After participants watched moving pictures on psychological and biological phenomena, they were asked to choose appropriate cause and justify their choices. Results of this study were as follows: First, young children made different inferences according to domain-specific causal mechanisms. Second, the developmental level of causal mechanisms has a gap between psychology and biology, and biological knowledge was proved to be separate from psychological knowledge during the preschool period. Third, young children's causal reasoning was different depending on the interaction effect of domain-specific mechanisms and domain-general conditional probability: children could make more inferences based on domain-specific causal mechanisms if conditional probability between domain-appropriate cause and effect was evident. To conclude, it can be inferred that the role of domain-specific causal mechanisms and domain-general conditional probability is not competitive but complementary in young children's causal reasoning.

Studies on the Biological and Chemical Properties of Musty Ginseng Root and its Causal Mechanism (적변삼의 생물.화학적 특성과 그 발생원인에 관하여)

  • 정영륜;오승환
    • Journal of Ginseng Research
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    • v.9 no.1
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    • pp.24-35
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    • 1985
  • Rusty root of ginseng has been known as one of the limiting factors in ginseng production in Korea. An attempt was, therefore, made to elucidate biological and chemical natures of the rusty root, and the redox Potential of the ginseng cultivated soils were measured and compared with diseased and non-diseased soils. Reddish discoloration was most frequently observed on the epidermis of ginseng root and the pigments were accumulated in all epidermal cells of the diseased lesions. The lower the redox potential of the ginseng cultivated soil was, the more severe the rusty root was observed. Fe content in the diseased epidermis was 3 times higher than that of healthy one. Organic acids such as oxalic, malonic, succinic, and citric acids were also higher in the mss root than in the healthy one. Thin layer chromatogram of phenolic acid fractions obtained from the epidermal cells of the rusty root of ginseng exhibited 3 to 4 unidentified substances not found in the healthy root. Also lignification of the epidermal cells and the activity of phenylalanine ammonia lyase were greater in the rusty root than the healthy root. Colony formation and conidia production of F. solani, And mycelial growth and sclerotium formation of Sclerotinia sp. isolated from ginseng root were suppressed in a nutritionally minimal medium supplemented with water extract of rusty ginseng root epidermis. It is, therefore, suggested that rusty root of ginseng is caused by unfavorable rhizosphere environmental stress or stresses resulting abnormal metabolism in the root as a selfdefence mechanism of non-specific resistance responses.

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Sequence Analysis and Potential Action of Eukaryotic Type Protein Kinase from Streptomyces coelicolor A3(2)

  • Roy, Daisy R.;Chandra, Sathees B.C.
    • Genomics & Informatics
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    • v.6 no.1
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    • pp.44-49
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    • 2008
  • Protein kinase C (PKC) is a family of kinases involved in the transduction of cellular signals that promote lipid hydrolysis. PKC plays a pivotal role in mediating cellular responses to extracellular stimuli involved in proliferation, differentiation and apoptosis. Comparative analysis of the PKC-${\alpha},{\beta},{\varepsilon}$ isozymes of 200 recently sequenced microbial genomes was carried out using variety of bioinformatics tools. Diversity and evolution of PKC was determined by sequence alignment. The ser/thr protein kinases of Streptomyces coelicolor A3 (2), is the only bacteria to show sequence alignment score greater than 30% with all the three PKC isotypes in the sequence alignment. S.coelicolor is the subject of our interest because it is notable for the production of pharmaceutically useful compounds including anti-tumor agents, immunosupressants and over two-thirds of all natural antibiotics currently available. The comparative analysis of three human isotypes of PKC and Serine/threonine protein kinase of S.coelicolor was carried out and possible mechanism of action of PKC was derived. Our analysis indicates that Serine/ threonine protein kinase from S. coelicolor can be a good candidate for potent anti-tumor agent. The presence of three representative isotypes of the PKC super family in this organism helps us to understand the mechanism of PKC from evolutionary perspective.

Attunement Disorder : A Disorder of Brain Connectivity (조현병(調鉉病) : 뇌 연결성의 장애)

  • Kim, Ki Won;Park, Kyung-Min;Jang, Hye-Ryeon;Lee, Yu Sang;Park, Seon-Cheol
    • Korean Journal of Biological Psychiatry
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    • v.20 no.4
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    • pp.136-143
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    • 2013
  • Objectives We reviewed cellular and synaptic dysconnectivity, disturbances in micro- and macro- circuitries, and neurodevelopmentally-derived disruptions of neural connectivity in the pathogenesis of schizophrenia. Method We reviewed the selected articles about disturbances in neural circuits which had been proposed as a pathogenetic mechanism of schizophrenia. Results The literature review reveals that schizophrenia may be a disease related to disturbance in neurodevelopmental mechanism, shown as 'a misconnection syndrome of neural circuit or neural network'. In descriptive psychopathological view, definition of a disorder of brain connectivity has limitation to explain other aspects of schizophrenia including deterministic strictness in thought process. Conclusion Schizophrenia is considered as a disorder of brain connectivity as well as a neurodevelopmental disorder related with genetic and environmental factors. We could make a suggestion that "JoHyeonByung (attunement disorder)" denotes the disturbances of psychic fine-tuning which correspond to the neural correlates of brain dysconnectivity metaphorically.

High-concentration Epigallocatechin Gallate Treatment Causes Endoplasmic Reticulum Stress-mediated Cell Death in HepG2 Cells

  • Ahn, Joon-Ik;Jeong, Kyoung-Ji;Ko, Moon-Jeong;Shin, Hee-Jung;Chung, Hye-Joo;Jeong, Ho-Sang
    • Genomics & Informatics
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    • v.7 no.2
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    • pp.97-106
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    • 2009
  • Epigallocatechin gallate (EGCG), a well-known antioxidant molecule, has been reported to cause hepatotoxicity when used in excess. However, the mechanism underlying EGCG-induced hepatotoxicity is still unclear. To better understand the mode of action of EGCG-induced hepatotoxicity, we examined the effect of EGCG on human hepatic gene expression in HepG2 cells using microarrays. Analyses of microarray data revealed more than 1300 differentially expressed genes with a variety of biological processes. Upregulated genes showed a primary involvement with protein-related biological processes, such as protein synthesis, protein modification, and protein trafficking, while downregulated genes demonstrated a strong association with lipid transport. Genes involved in cellular stress responses were highly upregulated by EGCG treatment, in particular genes involved in endoplasmic reticulum (ER) stress, such as GADD153, GADD34, and ATF3. In addition, changes in genes responsible for cholesterol synthesis and lipid transport were also observed, which explains the high accumulation of EGCG-induced lipids. We also identified other regulatory genes that might aid in clarifying the molecular mechanism underlying EGCG-induced hepatotoxicity.

Naturally-Occurring Novel Anticatcinogens : Conjugated Dienoic Derivatives of Linoliec Acid (CLA) (새로이 분류된 천연 항암제 : Conjugated Dienoic Derivatives of Linoleic Acid (CLA))

  • 하영래;마이클파리자
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.20 no.4
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    • pp.401-407
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    • 1991
  • Anticarcinogenic conjugated dienoic derivatives of linoleic acid (CLA) is present in grilled beef, cheese, and related foods, CLA is generated via isomerization of linoleic acid in the cow's rumen by anaerobic bacteria and food proceessing as well. Another source of CLA is its endogenous generation via the carbon centered free radical oxdation of linoleic acid. We propose that the formation and generation of CLA in vivo represents a previously unrecognized in situ "defense mechanism" against membrane attack by oxygen free radicals. The cis, 9-trans, 11 CLS isomer is selectively incorporated into cellular phospholipid, which exhibits a potent antioxidant, reduces the activation of 2-amino-3-methylimidazo, [4,5-f] quinoline (IQ) for baxterial mutagenesis, and inhibits ornithine decarboxylase(ODC) activity induced by 12-0-tetradecanoylphorbol-13-acetate (TPA). We believe that at least these biological activities of CLA explain the anticarcinogenic activity of CLA.

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c-fos Expression of Rat Brain by Antipsychotics : Contrasting Effects of Haloperidol and Clozapine (항정신병 약물에 의한 백서 뇌에서의 c-fos 발현 : 할로페리돌과 클로자핀의 효과 비교)

  • Lee, Min Soo;Han, Chang Su;Kim, Jeung Hyun;Kim, Young Tae;Kwak, Dong Il
    • Korean Journal of Biological Psychiatry
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    • v.3 no.1
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    • pp.115-120
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    • 1996
  • To investigate characteristic drug effects on the genetic basis, the authors administered haloperidol- the $D_2$ antagonist- and clozapine -the atypical antipsychotics with few extra- pyramidal side effects- to the rats. Then, we edobtain brain specimen from the striatum, prefrontal cortex, and cortical region and compared the degree of c-fos expression. The results are 1) haloperidol was found to produce a rapid and transient induction of dos mRNA expression in striatum as compared with cortex and prefrontal area. 2) clozapine was found to produce rapid induction of c-fos mRNA in striatum and prefrontal area. From these data, we can concluded that the mechanism of action of haloperidol is different from the mechanism of clozapine in gene expression.

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The Analysis of Non-pharmacological Intervention Study for Nonalcoholic Fatty Liver Disease: Intervention Types and Measurement Parameters (비알코올성 지방간질환에 대한 이해와 비약물적 중재 및 측정지표에 대한 문헌분석)

  • Kim, Na Hyun
    • Journal of Korean Biological Nursing Science
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    • v.15 no.2
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    • pp.43-53
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    • 2013
  • Purpose: This study was intended to analyze the types and measurement parameters of non-pharmacological interventional studies for nonalcoholic fatty liver disease (NAFLD). Methods: NAFLD related literatures were systematically reviewed. The existing literatures were searched electronically using the data base of PubMed, a Medline data base of the National Library of Medicine with the key words of nonalcoholic fatty liver disease, NAFLD, nonalcoholic steatohepatitis, and NASH. The criteria for inclusion in this review were 1) non-pharmacological intervention, 2) human, 3) English. Finally, 20 articles were included in the review. Results: The major findings of this study were as follows: 1) the types of non-pharmacological intervention were exercise (35%), caloric restriction (30%), and lifestyle modification with combination both of exercise and caloric restriction (35%), 2) Almost all studies adopted various measurement parameters derived from pathophysiological mechanism-based biomarkers such as anthropometric indices, biochemical parameters, body fat mass, and liver biopsy results. Conclusion: Non-pharmacological interventions have been reported to be effective to improve NAFLD status, and many objective biomarkers confirmed supported these findings. Therefore, the development of nursing interventions for NAFLD subjects is needed and the consideration of using mechanism-based biomarkers is suggested to verify nursing outcomes objectively.

Non-coding RNAs Associated with Biotic and Abiotic Stresses in Plants

  • Kang, Han-Chul;Yoon, Sang-Hong;Lee, Chang-Muk;Koo, Bon-Sung
    • Journal of Applied Biological Chemistry
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    • v.55 no.2
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    • pp.71-77
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    • 2012
  • Many of biochemical or physiological processes can be regulated by non-coding RNAs as well as coding RNAs in plants, animals and microbes. Recently, many small RNAs including microRNAs (miRNAs) and endogenous small interference RNAs (siRNAs) and long non-coding RNAs have been discovered from ubiquitous organisms including plants. Biotic and abiotic stresses are main causal agents of crop losses all over the world. Much efforts have been performed for understanding the complex mechanism of stress responses. Up to date, many of these researches have been related with the identification and investigation of stress-related proteins, showing limitation to resolve the complex mechanism. Recently, non-coding RNAs as well as coding genes have been gradually interested because of its potential roles in plant stress responses as well as other biophysical aspects. In this review, various potential roles of non-coding RNAs, especially miRNAs and siRNAs, are reviewed in relation with plant biotic and abiotic stresses.