• Clinical and Experimental Reproductive Medicine
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• v.38 no.4
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• pp.193-202
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• 2011

Objective: We found previously that $interferon$ $regulatory$ factor ($Irf$)-1 is a germinal vesicle (GV)-selective gene that highly expressed in GV as compared to metaphase II oocytes. To our knowledge, the function of $Irf-1$ in oocytes has yet to be examined. The present study was conducted to determine the relationship between retinoic acid (RA) and RA-mediated expression of $Irf-1$ and the mouse oocyte maturation. Methods: Immature cumulus-oocyte-complexes (COCs) were collected from 17-day-old female mice and cultured $in$ $vitro$ for 16 hours in the presence of varying concentrations of RA (0-10 ${\mu}M$). Rate of oocyte maturation and activation was measured. Gene expression was measured by quantitative real-time reverse transcription-polymerase chain reaction (RT-PCR) and cytokine secretion in the medium was measured by Bio-Plex analysis. Apoptosis was analyzed by terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) assay. Results: The rates of oocyte maturation to metaphase II and oocyte activation increased significantly with RA treatment (10 nM-1 ${\mu}M$). With 100 nM RA treatment, lowest level of $Irf-1$ mRNA and cumulus cell's apoptosis was found. Among 23 cytokines measured by Bio-Plex system, the substantial changes in secretion of tumor necrosis factor-${\alpha}$, macrophage inflammatory protein-$1{\beta}$, eotaxin and interleukin-12 (p40) from COCs in response to RA were detected. Conclusion: We concluded that the maturation of oocytes and $Irf-1$ expression are negatively correlated, and RA enhances the developmental competence of mouse immature oocytes $in$ $vitro$ by suppressing apoptosis of cumulus cells. Using a mouse model, results of the present study provide insights into improved culture conditions for $in$ $vitro$ oocyte maturation and relevant cytokine production and secretion in assisted reproductive technology.

• Geotechnical Engineering
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• v.14 no.6
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• pp.153-166
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• 1998

This paper shows the results of a series of model tests on the behavior of steel pipe pile which is subjected to lateral and inclined loads in homogeneous and non-homogeneous Nak-dong River sands. Non-homogeneous soil consisted of two layers, upper and lower layer. The purpose of the present paper is to investigate the effect of ratio of lower layer height to embedded pile length, ratio of soil modules of upper layer to lower layer and inclined load on the behavior of single pile. These effects can be quantified only by the results of model tests. As a result. in non-homogeneous sand soil, it is shown that the lateral behavior depends upon the ratio of soil modules of upper layer to lower layer more than other factors. And it was found that the relationship between the deflection ratio of non-homogeneous sand to homogeneous sand and the ratio of lower layer height to embedded pile length can be fitted to exponential function of H/L by model tests results. For the inclined load applied, it is shown that the bending moment-depth relationship is not similar to the case of laterally loaded pile and the depth of maximum bending moment at relative density of 90% increases about 70% more than the pile only loaded laterally.

• Tuberculosis and Respiratory Diseases
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• v.55 no.2
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• pp.165-174
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• 2003

Background : Asthma is one of the most prevalent diseases in Korea. Although the guidelines of asthma management were reported in Korea, the present pattern of asthma management by primary physicians has not been studied. The purpose of this study is to elucidate the pattern of asthma management by primary physicians. Methods : In November 2002, 710 primary physicians specializing in internal medicine in Seoul, Korea were provided with two scenarios of asthmatic patients, one mild and the other severe. By mail or interview, the physicians were asked several questions about their present pattern of asthma management for the patients in each scenario. Results : Among 710 primary physicians, we obtained the answers from 325 physicians (response rate 46%). The most preferred prescription was oral theophylline. 71% and 81% of the physicians answered that they would prescribe oral theophylline for the mild and severe asthmatics, respectively. The next prescription preferred were mucolytics and oral ${\beta}_2$-agonist, in that order. However, 36% and 56% of the physicians answered that they would prescribe inhaled steroids for the mild and severe asthmatics, respectively. Among diagnostic tests, physicians preferred pulmonary function test to the rank next to chest radiography. Conclusion : The primary physicians in Seoul prefer oral bronchodilators to inhaled steroids in asthma management. More efforts should be made to reduce the difference between the present pattern of asthma management by primary physicians and the asthma guidelines.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.27 no.1
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• pp.1-8
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• 2005

This study was aimed to characterize osteogenic potential of rat bone marrow stromal cells (BMSC) isolated with standard flushing method and investigate the plasticity of transdifferentiation between osteoblastic and adipocytic lineage of cultured BMSC. Unlike aspiration method in human, rat bone marrow was extracted by means of irrigation with culture media that elevates the possibility of co-extraction of committed osteoprogenitor, or preosteoblast or other progenitor cells of several types present inside bone marrow. The cultured stromal cells showed high ALP activity which is representative marker of osteoblast without any treatment. Osteogenic inducers such as Dex and BMP-2 were examined for the evaluation of their effect on osteogenic and adipocytic differentiation of stromal cells, because they function as osteoinductive agent in stromal cells, but simultaneously induce adipogenic differentiation. Osteogenic differentiation was evaluated by measuring alkaline phosphatase activity or mRNA expression of osteoblast markers such as osteopontin, bone sialoprotein, collagen type I and CbfaI, and in vitro matrix mineralization by von Kossa staining. Oil red staining method was used to detect adipocyte and adipocytic marker, aP2 and $PPAR{\gamma}2$ expression was examined using RT-PCR. It can be supposed that irrigation procedure resulted in high portion of already differentiation-committed osteoprogenitor cell showing elevated ALP activity and strong mineralization only under the supplement of $100{\mu}M$ ascorbic 2-phosphate and 10mM ${\beta}$-glycerophosphate without any treatment of osteogenic inducers such as Dex and BMP-2. Dex and BMP-2 seemed to transdifferentiate osteoprogenitor cells having high ALP activity into adipocytes temporarily, but continuous treatment redifferentiated into osteoblast and developed in vitro matrix mineralization. This property must be considered either in tissue engineering for bone regeneration, or in research of characterization of osteogenic differentiation, with rat BMSC isolated by the standard irrigation method.

• International Journal of Oral Biology
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• v.35 no.2
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• pp.61-67
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• 2010

Selenoprotein S (SelS) is widely expressed in diverse tissues where it localizes in the plasma membrane and endoplasmic reticulum. We studied the potential function of SelS in erythrocyte differentiation using K562 cells stably over-expressing SelS wild-type (WT) or one of two SelS point mutants, $U_{188}S$ or $U_{188}C$. We found that in the K562 cells treated with $1\;{\mu}M$ Ara-C, SelS gradually declined over five days of treatment. On day 4, intracellular ROS levels were higher in cells expressing SelS-WT than in those expressing a SelS mutant. Moreover, the cell cycle patterns in cells expressing SelS-WT or $U_{188}C$ were similar to the controls. The expression and activation of SIRT1 were also reduced during K562 differentiation. Cells expressing SelS-WT showed elevated SIRT1 expression and activation (phosphorylation), as well as higher levels of FoxO3a expression. SIRT1 activation was diminished slightly in cells expressing SelS-WT after treatment with the ROS scavenger NAC (12 mM), but not in those expressing a SelS mutant. After four days of Ara-C treatment, SelS-WT-expressing cells showed elevated transcription of $\beta$-globin, $\gamma$-globin, $\varepsilon$-globin, GATA-1 and zfpm-1, whereas cells expressing a SelS mutant did not. These results suggest that the suppression of SelS acts as a trigger for proerythrocyte differentiation via the ROS-mediated downregulation of SIRT1.

• Tuberculosis and Respiratory Diseases
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• v.79 no.1
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• pp.22-30
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• 2016

Background: The purpose of this study was to document outcomes following withdrawal of a single inhaler (step-down) in chronic obstructive pulmonary disease (COPD) patients on triple therapy (long-acting muscarinic antagonist and a combination of long-acting ${\beta}2$-agonists and inhaled corticosteroid), which a common treatment strategy in clinical practice. Methods: Through a retrospective observational study, COPD patients receiving triple therapy over 2 years (triple group; n=109) were compared with those who had undergone triple therapy for at least 1 year and subsequently, over 9 months, initiated inhaler withdrawal (step-down group, n=39). The index time was defined as the time of withdrawal in the step-down group and as 1 year after the start of triple therapy in the triple group. Results: Lung function at the index time was superior and the previous exacerbation frequency was lower in the step-down group than in the triple group. Step-down resulted in aggravating disease symptoms, a reduced overall quality of life, decreasing exercise performance, and accelerated forced expiratory volume in 1 second ($FEV_1$) decline ($54.7{\pm}15.7mL/yr$ vs. $10.7{\pm}7.1mL/yr$, p=0.007), but there was no observed increase in the frequency of exacerbations. Conclusion: Withdrawal of a single inhaler during triple therapy in COPD patients should be conducted with caution as it may impair the exercise capacity and quality of life while accelerating $FEV_1$ decline.

• Clinical and Experimental Reproductive Medicine
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• v.31 no.2
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• pp.111-117
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• 2004

Objectives: To investigate the effect of LH receptor in folliculogenesis, we confirm the expression level of LH receptor (LH-R) mRNA in human granulosa cells (GCs) and its expression levels were analyzed by comparison to embryo developmental rate and pregnancy rate. Materials and Methods: GCs were obtained at the time of oocyte retrieval from the patients undergoing IVF-ET program. The patients were divided into two groups: Group I (n=20) is poor responder (retrieved oocyte(s)$\leq$3ea), Group II (n=80) is normal responder (retrieved oocytes>3ea). After the extraction of total RNA, semiquantitative RT-PCR was performed and the expression level of LH-R mRNA was normalized by $\beta$-actin. Statistical analysis was performed by using $X^2$ test, Student's t-test and Pearson correlation. Results: In Group II, the relative values of LH-R mRNA (0.680 vs. 0.463, p<0.005) and pregnancy rate (54.7% vs. 23.1%, p<0.05) were significantly higher than in Group I. Number of retrieved oocyte(s) was gradually increased when the expression of LH-R mRNA was increased (p<0.05). But the quality of retrieved oocyte and transferred embryo were not related with the expression of LH-R mRNA. When the pregnancy rate was compared with FSH only group and FSH combined with hMG group in the ovarian stimulation protocol, FSH combined with hMG group was significantly higher than FSH only group in Group I (37.5% vs. 0%), and the expression of LH-R mRNA was significantly higher in hMG combined group than FSH only group (p<0.05). Conclusion: Expression level of LH-R mRNA has important role in ovarian function related with the response to gonadotrophin in human folliculogenesis. Furthermore these data might provide the evidence that additional use of hMG is helpful to poor responders.

• Clinical and Experimental Reproductive Medicine
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• v.36 no.2
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• pp.89-100
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• 2009

SLE 등의 자가면역질환 병인론에 있어서 $CD4^+$ T 조력 림프구 (T helper cell)의 기능과 항상성 조절의 이상이 중요하다는 것은 알려진 사실이지만 $CD4^+$ T 조력 림프구 (T helper cell)의 발달과 기능에 대한 성호르몬의 정확한 역할에 대하여는 아직 확립되어 있지 않은 실정이다. 에스트로겐의 $CD4^+$ T 림프구에 대한 여러 방면의 작용에 대한 결과는 에스트로겐 매개 신호가 전달되는 정황에 매우 의존적이라고 할 수 있으며, 또한 에스트로겐이 B 림프구와 항원발현세포들 같이 T 림프구 기능을 변화시킬 수 있는 다른 분획 세포들의 기능에 대해서도 영향을 미칠 수 있다는 사실을 고려한다면, 에스트로겐이 $CD4^+$ T 림프구매개반응에 미치는 작용은 매우 복잡하다고 할 수 있다. 현재로선 이런 과정들과 관련된 에스트로겐의 정확한 기전에 대한 연구 성과는 현재로선 아직걸음마 단계에 지나지 않는다고 볼 수 있다. 일부 분자학적 표적들의 발견에도 불구하고 ER-$\alpha$와 ER-$\beta$, 또는 이런 표적들의 조절에 대한 유전자적 또는 비유전자적 경로의 상대적 역할에 대해서는 현재로선 알려진 바가 많지 않은 것 또한 사실이며, T 림프구 자체의 미세 환경과 ER 매개 전사반응에 영향을 미칠 수 있는 방법 역시 아직까진 알려진 바가 없다. 따라서 에스트로겐의 $CD4^+$ T 림프구에 대한 다각적 영향을 규명하는 데 있어 이런 경로들에 대한 보다 체계적이고 상세한 연구가 반드시 필요하다. 최근 골다공증의 병인에 있어 에스트로겐에 의한 TNF 및 RANK-RANKL계 억제에 대해 연구가 심도 있게 진행됨으로써 결과적으로 다른 시토카인과 면역세포들에 대한 영향이 간접적으로 규명되고 있는 점은 매우 고무적인 현상이라고 여겨진다. 이러한 연구들은 추후 에스트로겐의 면역 및 염증체계에 대한 특징적 작용을 규명하는데 있어서 밑거름이 될 수 있을 것이다. 나아가 호르몬 자체, 또는 SERM 같은 준호르몬제제들이 면역계에 미치는 영향을 분자학적으로 규명함으로써 향후 이러한 지식들이 또한 류마티스성 자가면역질환이나 만성염증성질환, 또는 전신성 감염질환에 있어 면역글로불린이나 기타 다른 기존 치료 약제들을 대체 보완할 수 있는 호르몬 치료로 이어질 수 있는 결정적인 단서를 제공할 수 있을 것이라 기대할 수 있을 것이다.

• Korean journal of applied entomology
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• v.52 no.1
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• pp.5-12
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• 2013

The Hawaiian beet webworm (Spoladea recurvalis) is one of the serious insect pests found on red beet (Beta vulgaris var. conditiva) in Korea. The study was conducted to investigate the development period of S. recurvalis at various constant temperatures, 15.0, 17.5, 20.0, 22.5, 25.0, 27.5, 30.0, 32.5 and $35.0^{\circ}C$, with $65{\pm}5%$ RH and a photoperiod of 16L:8D. The developmental period from egg to pre-adult was 51.0 days at $17.5^{\circ}C$ and 14.6 days at $35.0^{\circ}C$. The developmental period of S. recurvalis was decreased with increasing temperature. The relationship between the developmental rate and temperature was fitted well by linear regression analysis ($R^2{\geq}0.87$). The lower developmental threshold and effective accumulative temperature of the total immature stage were $10.4^{\circ}C$ and 384.7 degree days, respectively. The nonlinear relationship between the temperature and developmental rate was well described by the Lactin model. The relationship between the cumulative frequency and normalized distributions of the developmental period for each life stage were fitted to the Weibull function with $R^2=0.63{\sim}0.87$.

• Journal of Energy Engineering
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• v.5 no.1
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• pp.56-64
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• 1996

The objective of this investigation is to establish the rejection characteristics of caesium and cobalt from radioactive liquid waste by chemical/ultrafiltration process. An extensive experimental investigation was conducted with inactive caesium and cobalt ions, utilizing ultrafiltration stirred cell. Caesium and cobalt could be effectively removed from waste solution using copper ferrocyanide and polyarcylic acid(PAA). The rejection dependence of the caesium was found to be a function of caesiun to potassium copper ferrocyanide feed molar ratio. The binding behavior of caesium on K$_2$Cu$_3$(Fe(CN)$\sub$6/)$_2$, particles was explained in terms of a Langmuir adsorption isotherm. When Cs/K$_2$Cu$_3$(Fe(CN)$\sub$6/)$_2$molar ratio was 1.5, the removal of caesium was the most efficient. The rejection efficiency of cobalt is dependent upon various parameters such as pH, cobalt concentration and PAA concentration. The rejection behavior of cobalt was explained in term of a equilibrium model taking into account the reaction between the ligand group, the proton and the cobalt ion. At the conditions of PAA/Co ratio of 2 and pH of 5.6, the removal of cobalt was over 90%. Also, the effect of chemical addition sequence for the simultaneously removal of caesiun and cobalt was discussed.