• Title/Summary/Keyword: Gil-ho Kim

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SIRT1 Suppresses Activating Transcription Factor 4 (ATF4) Expression in Response to Proteasome Inhibition

  • Woo, Seon Rang;Park, Jeong-Eun;Kim, Yang Hyun;Ju, Yeun-Jin;Shin, Hyun-Jin;Joo, Hyun-Yoo;Park, Eun-Ran;Hong, Sung Hee;Park, Gil Hong;Lee, Kee-Ho
    • Journal of Microbiology and Biotechnology
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    • v.23 no.12
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    • pp.1785-1790
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    • 2013
  • The synthetic machinery of ATF4 (activating transcription factor 4) is activated in response to various stress conditions involved in nutrient restriction, endoplasmic reticulum homeostasis, and oxidation. Stress-induced inhibition of proteasome activity triggers the unfolded protein response and endoplasmic reticulum stress, where ATF4 is crucial for consequent biological events. In the current study, we showed that the $NAD^+$-dependent deacetylase, SIRT1, suppresses ATF4 synthesis during proteasome inhibition. SIRT1 depletion via transfection of specific siRNA into HeLa cells resulted in a significant increase in ATF4 protein, which was observed specifically in the presence of the proteasome inhibitor MG132. Consistent with SIRT1 depletion data, transient transfection of cells with SIRT1-overexpressing plasmid induced a decrease in the ATF4 protein level in the presence of MG132. Interestingly, however, ATF4 mRNA was not affected by SIRT1, even in the presence of MG132, indicating that SIRT1-induced suppression of ATF4 synthesis occurs under post-transcriptional control. Accordingly, we propose that SIRT1 serves as a negative regulator of ATF4 protein synthesis at the post-transcriptional level, which is observed during stress conditions, such as proteasome inhibition.

Comparative Study of Growth and Gonad Maturation in Diploid and Triploid Marine Medaka, Oryzias dancena

  • Park, In-Seok;Gil, Hyun Woo;Lee, Tae Ho;Nam, Yoon Kwon;Kim, Dong Soo
    • Development and Reproduction
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    • v.20 no.4
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    • pp.305-314
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    • 2016
  • The marine medaka, Oryzias dancena is a suitable sample as a laboratory animal because it has a small size and clearly distinguishes between female and male. Data on the growth and maturity of the diploid and triploid sea cucurbit species suitable for laboratory animals are very useful for studying other species. Triploidy was induced in the marine medaka by cold shock treatment ($0^{\circ}C$) of fertilized eggs for 45 min, applied two minutes after fertilization. The diploid and triploid male fish were larger than their female counterparts (P<0.05), and the concentrations of thyroid stimulating hormone (TSH) and thyroxine (T4) were higher in the induced triploids over 1 year (P<0.05). In both the diploid and tri-ploid groups the concentrations of TSH and T4 were higher in the male fish than in the females (P<0.05), while the testo-sterone and estradiol-$17{\beta}$ concentrations in the induced triploids were lower than in the diploids (P<0.05). The gonadosomatic index (GSI) of the triploid fish was lower than that for the diploids, and the GSI for females in each ploidy group were higher than that for the males. For both groups the GSI was highest at 4 months of age, and decreased thereafter to 12 months. Analysis of the gonads of one-year-old triploid fish suggested that the induction of triploidy probably causes sterility in this species; this effect was more apparent in females than in males.

(-)-Epigallocatechin Gallate Inhibits the Pacemaker Activity of Interstitial Cells of Cajal of Mouse Small Intestine

  • Kim, Kweon-Young;Choi, Soo-Jin;Jang, Hyuk-Jin;Zuo, Dong-Chuan;Shahi, Pawan Kumar;Parajuli, Shankar Prasad;Yeum, Cheol-Ho;Yoon, Pyung-Jin;Choi, Seok;Jun, Jae-Yeoul
    • The Korean Journal of Physiology and Pharmacology
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    • v.12 no.3
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    • pp.111-115
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    • 2008
  • The effects of (-)-epigallocatechin gallate (EGCG) on pacemaker activities of cultured interstitial cells of Cajal (ICC) from murine small intestine were investigated using whole-cell patch-clamp technique at $30^{\circ}C$ and $Ca^{2+}$ image analysis. ICC generated spontaneous pacemaker currents at a holding potential of -70 mV. The treatment of ICC with EGCG resulted in a dose-dependent decrease in the frequency and amplitude of pacemaker currents. SQ-22536, an adenylate cyclase inhibitor, and ODQ, a guanylate cyclase inhibitor, did not inhibit the effects of EGCG. EGCG-induced effects on pacemaker currents were not inhibited by glibenclamide, an ATP-sensitive $K^+$ channel blocker and TEA, a $Ca^{2+}$-activated $K^+$ channel blocker. Also, we found that EGCG inhibited the spontaneous $[Ca^{2+}]_i$ oscillations in cultured ICC. In conclusion, EGCG inhibited the pacemaker activity of ICC and reduced $[Ca^{2+}]_i$ oscillations by cAMP-, cGMP-, ATP-sensitive $K^+$ channel-independent manner.

Toxicity Evaluation of Agricultural Insecticides on Workers of Pharaoh Ant, Monomorium pharaonis (Hyme-noptera : Formicidae) (애집개미 (Monomorium pharaonis) 일개미에 대한 농업용 살충제의 독성평가)

  • Kang, Shin-Ho;Han, Jong-Been;Park, Shin-Sub;Kim, Gil-Hah
    • The Korean Journal of Pesticide Science
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    • v.10 no.3
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    • pp.218-224
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    • 2006
  • Toxicities of 34 agricultural insecticides was tested against Monomorium pharaonis workers by diet dipping method. Ten insecticides among them, bifenthrin, chlorpyrifos, chlorpyrifos-methyl, cypermethrin, dichlorvos, fenthion, fenitrothion, methidathion, pirimifos-methyl, and phenthoate showed 100% rapid mortality. $LC_{50}$ (ppm) values of selected insecticides were appeared on the order of pirimifos-methyl (0.33), chlorpyrifos-methyl (0.76), phenthoate (1.70), bifenthrin (1.78), dichlorvos (2.50), cypermethrin (9.92), chlorpyrifos (22.21), fenitrothion (36.58), fenthion (40.96), and methidathion (64.34). $LT_{50}$ (day) values by diet dipping method showed that dichlorvos, benfuracarb and cypermethrin acted more rapid than boric acid and hydramethylnon. The values of the former three were 0.25, 0.38 and 0.27 days, and those of the latter two were 3.4 and 2.6 days, respectively. In persistance effect tests, chlorpyrifos-methyl, fenthion and methidathion showed over 90% insecticidal activity for 13 days.

Contact and Residual Toxicities of 26 Insecticides Against the Cigarette Beetle, Lasioderma serricorne and the Maize Weevil, Sitophilus zeamais (권연벌레와 어리쌀바구미에 대한 26종 살충제의 접촉독성 및 잔효성)

  • Cho, Sun-Ran;Shin, Youn-Ho;Yoon, Chang-Mann;Kim, Gil-Ha
    • The Korean Journal of Pesticide Science
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    • v.15 no.3
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    • pp.310-316
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    • 2011
  • This study was performed to evaluate the contact toxicity and residual toxicity of the 26 commercially registered insecticides against cigarette beetle, Lasioderma serricorne and maize weevil, Sitophilus zeamais adult. Among 26 insecticides, seven insecticides (chlorpyrifos, chlorpyrifos-methyl, fenitrothion, fenthion, phenthoate, cypermethrin, ${\alpha}$-cyhalothrin) against L. serricorne adult and five insecticides (chlorpyrifos, chlorpyrifos-methyl, fenitrothion, fenthion, phenthoate) against S. zeamais adult showed perfect mortality, $LC_{50}$ (ppm) values of those selected insecticides were appeared lowest value on ${\alpha}$-cyhalothrin (1.46) against L. serricorne adult and chlorpyrifos-methyl (0.64) against S, zeamais adult, respectively. However, chlorpyrifos-methyl still remain high toxicity until 90th days after treatment against both L. serricorne and S. zeamais adults. From above results, it will be useful information to select insecticides effective against L. serricorne and S. zeamais adults.

A Study on Site Selection for Reeve's turtle(Maunemys reevesii) Habitats Using Habitat Suitability Index (서식지 적합성 지수(HSI)를 활용한 남생이 서식지 복원 대상지 선정 방안 연구)

  • Park, Yong-Su;Chang, Min-Ho;Cha, Jin-Yeol;Cho, Dong-Gil;Kim, Seung-Hee;Lee, Sung-Woo
    • Journal of the Korean Society of Environmental Restoration Technology
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    • v.18 no.3
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    • pp.109-118
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    • 2015
  • This study was performed to propose the site selection plan for the restoration of the target Reeve's turtle (Maunemys reevesii) habitat and has developed the AHP model to select the optimal site for Reeve's turtle habitat restoration on the basis of the Reeve's turtle Habitat Suitability Index (HSI) items (factors and variables). The assessment areas were established by the Reeve's turtle HSI factors such as breeding space, feed, cover, water, threatening factors and others and the sub-assessment items by each assessment area were established based on the Reeve's turtle HSI variables. The weighting values of the assessment areas and items were calculated by the developed AHP method. The weighting values of the 5 assessment areas were arranged in order as breeding space(0.293), food(0.273), water(0.217), cover(0.113), and threatening factor(0.104). The final weighting values of the 17 assessment items were arranged in order of height as all kind of food(0.222), water depth(0.096), altitude of spawning ground(0.093). The scoring criteria according to the assessment items and factors were marked and applied by equal intervals considering the criteria by HSI items of the Reeve's turtle and finally the scoring criteria diagram as been proposed for the optimal site selection of the Reeve's turtle habitat restoration.

The Adequacy of a Cross Table Lateral Cervical X-ray in Severely Traumatized Korean Patients (한국인 중증 외상 환자에서 촬영한 경추 외측면 단순 방사선 영상의 적절성)

  • Lee, Kyung-Hag;Kim, Yeong Cheol;Choi, Seok Ho;Han, Gook Nam;Lee, Soo Un;Lee, Jung Eun;Suh, Gil Joon;Yoon, Yeo-Kyu
    • Journal of Trauma and Injury
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    • v.25 no.4
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    • pp.241-246
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    • 2012
  • Purpose: The objective of this study was to investigate the appropriateness of the cross table lateral cervical X-ray used in the emergency department for severely traumatized Korean patients. Methods: Patients visiting our institution from May 2011 to May 2012, who had injury severity score (ISS) > 15 and who received a cervical X-ray in the emergency department, were included in this study. Data including demographics, ISS score, GCS score, and place where the x-ray was taken were collected to evaluate their relationship with appropriate coverage of the cervical X-ray. The appropriateness of a cervical cross lateral view X-ray was evaluated using exposure of the basion, and the opisthion, as well as the distal level of exposure. Results: Fifty-two patients were included in this study. The identification rate of the basion was 79.2%, and the identification rate of the opisthion was 88.7%. Complete exposure of C7/T1 was accomplished in 3.8% of the patients. The ISS was higher for X-ray taken in the trauma bay, but the range of exposure showed no difference between the places where the X-rays taken. Patients who had exposure of C 5/6 or more had lower body weight and body mass index (BMI) compared with unexposed patients. Conclusion: In severely traumatized Korean patients, the adequacy of the cross table lateral cervical X-ray was inappropriate in most cases. No difference was observed in the exposure range between the places where the X-rays were taken, and patients with less exposure showed higher body weight and higher BMI.

Two Cases of Patients Diagnosed as Junggi-haham(中氣下陷) (중기하함(中氣下陷)으로 진단된 안검하수 환자와 요실금 환자의 한방치료 치험 각 1례)

  • Hyun, Jin-Oh;Kim, Jin-Su;Choi, Dong-Jun;Jung, Seung-Hyun;Lim, Seong-Woo;Sin, Gil-Jo;Lee, Won-Chul;Han, Chang-Ho
    • The Journal of Internal Korean Medicine
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    • v.27 no.4
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    • pp.1035-1045
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    • 2006
  • Junggi-haham (中氣下陷) is a term referring to lethargic symptoms such as digestive system disorder originating from energy deficiency. The authors applied therapy including Bojungikgi-tang(or Seungyangikgi-tang) and Bi-jeonggyuk method to two patients, one having ptosis and the other stress urinary incontinence, respectively, as Junggi-haham. Bojungikgi-tang is an herbal medication preparation and Bi-jeonggyuk is an acupuncture therapy method, and both are used to treat Junggi-haham symptoms. The combined treatment showed positive outcome, and the result suggests that Bojungikgi-tang and Bi-jeonggyuk are effective treatments for patients diagnosed as Junggi-haham.

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Vasorelaxation Effect of Butanol Fraction of Crataegi Fructus due to LC20 dephosphorylation via increase of Myosin Phosphophatase activity (산사 Butaol 분획이 PGF2$\alpha$-유도 혈관평활근수축의 억제에 미치는 신호전달 연구)

  • Liang Liou Jia;Choi Ho Jeong;Kim Gil-Whon;Shin Heung Mook
    • Journal of Physiology & Pathology in Korean Medicine
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    • v.17 no.2
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    • pp.461-466
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    • 2003
  • The primary mechanism of smooth muscle contraction is phosphorylation of the 20 kDa myosin light chains(LC20) by a myosin light chain kinase(MLCK). Relaxation, then, is generally the result of dephosphorylation of LC20 by myosin phosphatase(MP). Changes in MP activity is one of the important mechanisms in the regulation of Ca2+-sensitivity. Inhibition of MP activity is linked to an increase in phosphorylated myosin light chain(MLC) without an increase in [Ca/sup 2+/]i-levels. It is now generally accepted that Rho-kinase phosphorylates 130 kDa regulatory and myosin binding subunits(M130, MYPT) of MP, which results in an inhibition of MP activity. In addition Rho-kinase can also directly phosphorylate MLC. In the present study, LC20 phosphorylation and MP subunits translocation to the cell membrane were investigated in freshly isolated ferret portal vein smooth muscle single cells treated with PGF2α. We also examined the effect of Y27632(10-5mol/L), Rho-kinase inhibitor, in the MP subunits localization to compare with butanol fraction of Fructus Crataegi in its effect. Butanol fraction of Fructus Crataegi(BFFC; 1㎎/㎖) was more effective in PGF2α induced contraction than those of phenylephrine in its vasodilation effect. It significantly(P<0.05) dephosphorylated the LC20 at time indicated. In addition, the dissociation of subunits are inhibited by BFCF treatment. The results indicate that, in the smooth muscle cells, the relaxation effect of BFFC is associated with increase of MP activity based on inhibition of dissociation of the catalytic and targeting subunits of the phosphatase, and thus decrease the sensitivity of LC20 phosphorylation for Ca/sup 2+/.

Reliability for Multiple Reviewers by using Loglinear Models (로그선형모형을 이용한 복수 평가자들간의 신뢰도에 관한 연구)

  • Park, Byung-Joo;Lee, Sung-Im;Lee, Young-Jo;Kim, Dong-Hyun;Kwon, Ho-Jang;Bae, Jong-Myon;Shin, Myung-Hee;Ha, Mi-Na;Han, Sang-Whan
    • Journal of Preventive Medicine and Public Health
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    • v.30 no.4 s.59
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    • pp.719-728
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    • 1997
  • To guarantee the inter-reviewer reliability is very important in evaluating the quality of large number of clinical research papers by multiple reviewers. We cannot find reports on statistical methods for evaluating reliability for multiple raters in clinical research field. The purpose of this paper is to introduce the statistical methods focused on kappa statistic and five kinds of loglinear models for, which can be applied when evaluating the reliability of multiple raters. We have applied these methods to the result of a project, in which seven reviewers have evaluated the quality of 33 papers with regard to four aspects of paper contents including study hypothesis, study design, study population, study method, data analysis and interpretation. Among the five loglinear models including Symmetry model, Conditional symmetry model, Quasi-symmetry model, Independence model, and Quasi-independence model, Quasi-symmetry model shows the best model of fitting. And the level of reliability among seven reviewers revealed to be acceptable as meaningful.

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