• Title/Summary/Keyword: Mechanistic study

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A Mechanistic Study on the Early Stage-Events Involved in Low Temperature Stress in Clamydomonas reinhardtii (Clamydomonas reinhardtii의 냉해 초기과정에 관한 기작론적 연구)

  • Cho, Hyun-Soon;Kim, Chang-Sook;Jung, Jin
    • Applied Biological Chemistry
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    • v.37 no.6
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    • pp.433-440
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    • 1994
  • The exposure of Clamydomonas reinhardtii to low temperatures resulted in an accumulation of cellular pyruvate that dissipated when the chilled cells returned to ambient temperature. The dissipation of pyruvate accumulation was accompanied by an increase in the production level of superoxide radicals $(O_2^-)$ in cells. The formation of $O_2^-$ at an excessive level during the post-chilling period was apparently countered by a substantial activation of superoxide dismutase (SOD). All these results are similar to those observed previously in rice seedlings subjected to the cold-treatment, implicating that a common mechanism is probably underlying for the primary processes of chilling injury both in higher plants and in algae. It was also observed that the activation of Mn-containing SOD contributes the major share in the increase of SOD activity of whole algal cells. Because Mn-SOD is present only in mitochondria, the observation corroborates the concept that the $O_2^-$ scavenging enzyme would be induced to cope with the cold treatment-caused adverse situation in mitochondria where the toxic active oxygen is produced at rates far exceeding the normal rate.

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Mechanism of Cadmium Accumulation in the Cell of Cadmium-Tolerant Bacterium, Pseudomonas putida (카드뮴내성균(耐性菌)(Pseudomonas putida)에 의한 균체내(菌體內) 카드뮴 축적(蓄積) 기작(機作))

  • Heo, Jong-Soo;Cho, Ju-Sik;Han, Mun-Gyu
    • Korean Journal of Environmental Agriculture
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    • v.11 no.1
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    • pp.67-76
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    • 1992
  • A mechanistic study by which Cadmium-tolerant P.Putida C1 accumulates high conc of Cd in its cell body was performed. Approximately 57% Cd accumulated was distributed on the cell wall and the other 43% portion was in cytoplasm. 84% Cd of the Cd in the cell wall fractions present in the polyphosphate-polysaccharide fractions, but most of Cd in the cytoplasm fraction was in protein and nucleic acid. Cadmium affected the protein synthesis in P. Putida. The intracellular protein content was decreased by cadmium addition, but the soluble protein precipitated by ammonium sulfate($30{\sim}75%$ satruation) was increased as compared to that from the cells grwon without cadmium. Furthermore, in the cells grown with of cadmium, high-molecular-weight soluble protein was increased, with of cadmium, high-molecular-weight soluble protein was increased, compared with the cells grown without cadmium, but low-molecular-weight soluble protein was decreased. These results indicate that Cd inhibited the intracellular protein biosynthesis but enhance biosynthesis of the high-molecular-weight soluble protein precipitate by ammonium sulfate($30{\sim}75%$ saturation).

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Analysis and Mechanistic Investigation of Redox Process of 2-Amino-1-cyclopentene-1-dithiocarboxylate by Adsorptive Stripping Voltammetry on Glassy Carbon Electrode (Glassy Carbon 전극에서의 벗김 전압-전류법을 이용한 2-Amino-1-cyclopentene-1-dithiocarboxylate 의 분석과 전극 반응 메카니즘의 연구)

  • Yoon-Bo Shim;Duk-Soo Park;Sung-Nak Choi;Mi-Sook Won
    • Journal of the Korean Chemical Society
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    • v.32 no.1
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    • pp.37-47
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    • 1988
  • The electrochemical behavior of 2-Amino-1-cyclopentene-1-dithiocarboxylate (acdc) was investigated by the use of polarography, cyclic voltammetry and cathodic stripping voltammetry at glassy carbon electrode. In this study, it was found that the dimer of the acdc was deposited on the glassy carbon electrode via one-electron oxidation process at +0.25V vs. SCE. The ring formation between two dithio group occurs along with the elimination of one sulfur atom. The elimination of sulfur atom occurs via two electron oxidation process at +0.8V vs. SCE. The most sensitive cathodic stripping peak due to the formation of the dimer was observed at -0.85V vs. SCE. The peak relationship between current and concentration was fairly linear in the range of 3${\times}10^{-5}{\sim}1.0{\times}10^{-6}$M. The preconcentration procedure enhanced the sensitivity about 100 times for the analysis of acdc using diffusion current. Detection limit was found to be $2.5{\times}10^{-7}$M and relative standard deviation was ${\pm}$4.1 % at $5.0{\times}10^{-6}$M DC polarography.

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Inactivation of Bacterial Spores by High Pressure and Food Additive Combination (초고압과 식품첨가물 병용을 이용한 세균 포자의 살균)

  • Chung, Yoon-Kyung
    • Journal of Life Science
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    • v.21 no.8
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    • pp.1094-1099
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    • 2011
  • Antimicrobial efficacy of high pressure (HP) can be enhanced by the application of additional hurdles. The objective of this study was to assess the enhancement in pressure lethality by tert-butylhydroquinone (TBHQ) treatment, against bacterial spores that are considered significant in the food industry. Spores of Clostridium sporogenes, Bacillus cereus and B. subtilis were prepared. Spore suspensions containing TBHQ (200 ppm, dissolved in dimethyl sulfoxide, DMSO) were pressurized at 650 or 700 MPa at 54-72$^{\circ}C$ for 5 min. Inactivation of bacterial spores resulted only with HP treatment. The population of B. subtilis spores was more inactivated by HP than those of B. cereus and C. sporogenes spores. Inactivation of C. sporogenes spores using pressure was more affected by the germinated population, compared to Bacillus spores. The inactivation of Bacillus spores increased when pressurized at 70$^{\circ}C$, compared to 54$^{\circ}C$. On the other hand, the degree of germination-induced lethality for Bacillus spores decreased at 70$^{\circ}C$. When spores were treated with a combination of DMSO-HP and TBHQ-HP, these treatments seemed to protect the spores against HP, especially at 54$^{\circ}C$. Further mechanistic studies involved in inducing germination by HP and using a subsequent sporicidal agent will be needed for a better understanding of bacterial spore inactivation.

Beneficial effects of fermented black ginseng and its ginsenoside 20(S)-Rg3 against cisplatin-induced nephrotoxicity in LLC-PK1 cells

  • Han, Myoung-Sik;Han, Im-Ho;Lee, Dahae;An, Jun Min;Kim, Su-Nam;Shin, Myoung-Sook;Yamabe, Noriko;Hwang, Gwi Seo;Yoo, Hye Hyun;Choi, Suk-Jung;Kang, Ki Sung;Jang, Hyuk-Jai
    • Journal of Ginseng Research
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    • v.40 no.2
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    • pp.135-140
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    • 2016
  • Background: Nephrotoxicity is a common side effect of medications. Panax ginseng is one of the best-known herbal medicines, and its individual constituents enhance renal function. Identification of its efficacy and mechanisms of action against drug-induced nephrotoxicity, as well as the specific constituents mediating this effect, have recently emerged as an interesting research area focusing on the kidney protective efficacy of P. ginseng. Methods: The present study investigated the kidney protective effect of fermented black ginseng (FBG) and its active component ginsenoside 20(S)-Rg3 against cisplatin (chemotherapy drug)-induced damage in pig kidney (LLC-PK1) cells. It focused on assessing the role of mitogen-activated protein kinases as important mechanistic elements in kidney protection. Results: The reduced cell viability induced by cisplatin was significantly recovered with FBG extract and ginsenoside 20(S)-Rg3 dose-dependently. The cisplatin-induced elevated protein levels of phosphorylated c-Jun N-terminal kinase (JNK), p53, and cleaved caspase-3 were decreased after cotreatment with FBG extract or ginsenoside 20(S)-Rg3. The elevated percentage of apoptotic LLC-PK1 cells induced by cisplatin treatment was significantly abrogated by cotreatment with FBG and the ginsenoside 20(S)-Rg3. Conclusion: FBG and its major ginsenoside 20(S)-Rg3, ameliorated cisplatin-induced nephrotoxicity in LLC-PK1 cells by blocking the JNKep53ecaspase-3 signaling cascade.

Application and Prospective of Aroma Therapy for Preservation of Health(養生) (양생(養生)을 위한 향기치료(香氣治療)의 한의학적 적용(適用)과 전망(展望))

  • Lyu, Young-Su;Ko, Ki-Wan
    • The Journal of Internal Korean Medicine
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    • v.19 no.1
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    • pp.505-523
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    • 1998
  • Aroma therpay in the western classical medicine is compared with the mechanistic paradigm of Newton physics which is the foundation of western modern medicine. It is the therapy whose basic principle is very similar to the basic concepts of oriental medicine lasting thousands of years. We know that parts of their therapies are explained by Yin-Yan and five elements in Oriental Medicine. In the modern western medicine, as preventive medicine is becoming more and more important and moreover, health promotion and self healing care is being emphasized, Maintenanayce which is the oriental preventive medicine, acts in concert with the concept of New Age of Science and provides a way for the Oriental Medicine of the future. The health promotion and self healing care is similar to the thought of Maintenanayce in Oriental Medicine. Oriental Medicine has provided the concept of preventive ehaling care for a long time and built the foundation of the department of Maintenanayce. Among these method of Preservation of Health, We could find that of using fragrance throuth the several references. By comparing the department of Maintenanayce in oriental preventive medicine with the books and papers about aroma therapy, used in the fields of naturalpathy medicine, alternative medicine, and complementary medicine in the west, and by analyzing them, centering around references, to see whether they are reasonable and corresponding, the following conclusions have been reached. 1. We could see that aroma therapy of oriental preventive medicine could be applied to the fields of health promotion and self healing cure, recently appearing in the world of health medicine, as a modern way of Preservation of Health(養生). 2. We could see that western traditional aroma therapy take important position in alternative medicine and complementary medicine, and it could be developed as the transitional field of medical cure for the interchange between western and eastern medicine. 3. We could see that aroma therapy is not totally unknown therapy and there is some points of similarity in the traditional references of oriental medicine. Also, it is considered that the aroma therapy has a possibility of coming the front as an general therapy among various therapies. 4. aroma therapy will be actively applied to many fields such as oriental psychiatry, internal medicine of the respiratory system, pediatrics, oriental nursing, oriental dermatologic beauty, and preventive medicine. Therefore, we have a view that the combination between aroma therapy and oriental medicine will be fairly valuable to study as the general and transtional middle step on which it will prepare the situation of oriental medicine's reimportation from the west and we establish a bridgehead to export the oriental medicine.

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Evaluation of the Triage by Emergency Medical Technicians by Using Trauma Score for Occupant Injuries Caused by Motor Vehicle Collisions (자동차 탑승자 사고에서 외상계수를 이용한 구급대원의 중증도 분류 평가)

  • Kim, Sang Chul;Kim, Byung Woo;Tak, Yang Ju;Lee, Sang Hee
    • Journal of Trauma and Injury
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    • v.26 no.3
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    • pp.89-98
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    • 2013
  • Purpose: The assessment of trauma patients in the prehospital setting is difficult, but appropriate field triage is critical to the prognosis of trauma patients. We sought to evaluate the triage given by the emergency medical technicians (EMTs) using the trauma score to patients injured in motor vehicle collisions (MVCs). Methods: From June 2012 to July 2012, questionnaires were distributed to EMTs, who had transported injured patients to the study hospital. Scene records, photos of the damaged vehicle, and ambulance run sheets were used to provide physiologic, physical, and mechanistic information about the MVC. To evaluate the appropriateness of the injury assessment by EMTs, we compared their impressions with the hospital's final diagnosis within a 3 level triage system comprising both the maximum abbreviated injury scale (MAIS) and the injury severity score (ISS). Kappa (k) was calculated to evaluate the agreement between the triage by EMTs and the triage based on hospital's final diagnosis. Results: A total of 91 patients were analyzed by 31 EMTs. The percentage of males was 57.1%, the mean age was 44.5, and the mean MAIS and ISS were 2.7 and 16.6 respectively. While EMTs correctly diagnosed patient injuries to the extremities in 35.7%, and to the neck in 32.1%, pelvic injuries were missed in 80.0%. The agreement between the triage by the EMTs and the triage based on the hospital's final diagnosis was 62.6%(k=0.366) by the MAIS and 50.5%(k=0.234) by the ISS. The kappa value was higher in EMT-I than in EMT-II. Conclusion: In MVC, the assessment of injured patients by EMT-I was more appropriate, and the 3-level triage method based on the MAIS could contribute to a more accurate triage. Prospective studies to search for appropriate methods of field triage are required for programming practical education for EMTs.

Leaf Photosynthesis as Influenced by Mesophyll Cell Volume and Surface Area in Chamber-Grown Soybean (Glycine max) Leaves (중엽세포의 체적 및 표면적과 콩잎의 광합성 능력간 관계)

  • Jin Il, Yun;S. Elwynn, Taylor
    • KOREAN JOURNAL OF CROP SCIENCE
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    • v.33 no.4
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    • pp.353-359
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    • 1988
  • Variations in photosynthetic capacities of leaves differing in thickness were explained on the basis of relationships between gas exchange and internal leaf structure. The relative importance of gas diffusion and of biochemical processes as limiting for leaf photosynthesis was also determined. Mesophyll cell surface was considered to be the limiting internal site for gas diffusion. and cell volume to be indicative of the sink capacity for CO$_2$ fixation. Increases in cell surface area were assumed to reduce proportionately mesophyll resistance to the liquid phase diffusion of CO$_2$. Increased cell volume was thought to account for a proportional increase in reaction rates for carboxylation, oxygenation. and dark respiration. This assumption was tested using chamber-grown Glycine max (L.) Merr. cv. Amsoy plants. Plants were grown under 200, 400, and 600 ${\mu}$mol photons m$\^$-2/ s$\^$-1/ of PAR to induce development of various leaf thickness. Photosynthetic CO$_2$ uptake rates were measured on the 3rd and 4th trifoliolate leaves under 1000 ${\mu}$mol photons m$\^$-2/ s$\^$-1/ of PAR and at the air temperature of 28 C. A pseudo -mechanistic photosynthesis model was modified to accommodate the concept of cell surface area as well as both cell volume and surface area. Both versions were used to simulate leaf photosynthesis. Computations based on volume and surface area showed slightly better agreement with experimental data than did those based on the surface area only. This implies that any single factor, whether it is photosynthetic model utilized in this study was suitable for relating leaf thickness to leaf productivity.

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Cordycepin Induced Apoptosis via Intracellular Ca2+ Modulation and Mitochondrial Dysfunction in Human Prostate Cancer PC-3 Cells (전립선암 세포주인 PC-3에서 cordycepin에 의해 유도된 세포 내 칼슘농도 변화와 미토콘드리아 기능 상실을 통한 세포사멸 유도)

  • Kang, Dong-Min;Kim, Kwang-Youn;Yu, Sun-Nyoung;Jin, Young-Rang;Jeon, Hyun-Joo;Kim, Sang-Hun;Chun, Sung-Sik;Ko, Hack-Ryong;Ahn, Soon-Cheol
    • Journal of Life Science
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    • v.21 no.3
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    • pp.451-458
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    • 2011
  • Cordycepin (3'-deoxyadenosine), a nucleoside derivative isolated from Cordyceps militaris, is reported to have antitumor effects. However, neither its molecular mechanism nor its molecular targets are well understood. In the present study, molecular mechanisms for the anti-tumor effects of cordycepin were investigated in human prostate cancer PC-3 cells. The MTT assay was used to detect cell viability. Annexin V/FITC assay, reactive oxygen species (ROS) production, mitochondrial membrane potential (MMP), and $Ca^{2+}$ flux were used to assess for the presence of apoptosis. Western blot analysis was used to detect protein expression. Treatment of cordycepin resulted in significantly decreased cell viability of PC-3 cells in a dose- and time-dependent manner. A dose-dependent apoptotic cell death was also measured by flow cytometery analysis. Molecular mechanistic studies of apoptosis unraveled cordycepin treatment resulted in significant mitochondrial dysfunction, ROS production, and elevation of $Ca^{2+}$ concentrations. These phenomena were followed activation of caspase-3, subsequently leading to PARP cleavage and cell apoptosis. Taken together, cordycepin induces apoptosis in PC-3 cells through regulation of a mitochondrial mediated pathway.

Effects of 14 Chung-bu Medicinal Materials Described in the Dongui Bogam on Inflammatory Cytokines Production in HaCaT Keratinocytes (피부각질형성세포에서 동의보감 충부약재 14 종이 염증성 사이토카인 생성에 미치는 영향)

  • Park, Gunhyuk;Moon, Byeong Cheol;Lim, Hye-Sun
    • Journal of the Society of Cosmetic Scientists of Korea
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    • v.46 no.2
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    • pp.195-204
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    • 2020
  • The purpose of this study was to investigate the effects of 14 Chung-bu medicinal materials described in the Dongui Bogam on inflammatory cytokine production in HaCaT human keratinocyte cells. In order to confirm this possibility, we screened inhibition activity of 17 cytokines using Bio-Plex ProTM Human Cytokine 17-plex assay in HaCaT cell lines. Of the 14 Chung-bu medicinal materials, Holotrichia (Ho) and Scorpio (Sc) exerted inhibitory effects on interleukin (IL)-5 production; Ho, Mantidis Ootheca (MO), and Hirudo (Hi) exerted inhibitory effects on IL-6 production; Ho, MO, Lumbricus (Lu), Hi, and Meretricis Concha (MC) showed significant inhibitory effects on IL-8 production; Gecko (Ge), Bombycis Faeces (BF), Cicadidae Periostracum (CP), and MC showed significant inhibitory effects on IL-13 production; and Testudinis Chinemis Plastrum et Carapax (TCPC), BF, and Lu exerted significant inhibitory effects on MIP-1β production. Results indicated that the Chung-bu medicinal materials might be a good candicate as potential anti-inflammatory agents for inhibition of skin inflammation. However, further investigations on these materials, including mechanistic studies, should be carried out to validated the effects in human skin equivalent models of dermatitis.