• Journal of Microbiology
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• 제43권6호
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• pp.529-536
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• 2005

Viral infection causes stress to the endoplasmic reticulum (ER). The response to endoplasmic reticulum stress, known as the unfolded protein response (UPR), is designed to eliminate misfolded proteins and allow the cell to recover. The role of hepatitis C virus (HCV) non-structural protein NS4B, a component of the HCV replicons that induce UPR, is incompletely understood. We demonstrate that HCV NS4B could induce activating transcription factor (ATF6) and inositol-requiring enzyme 1 (IRE1), to favor the HCV subreplicon and HCV viral replication. HCV NS4B activated the IRE1 pathway, as indicated by splicing of X box-binding protein (Xbp-1) mRNA. However, transcriptional activation of the XBP-1 target gene, EDEM (ER degradation-enhancing $\alpha-mannosidase-like$ protein, a protein degradation factor), was inhibited. These results imply that NS4B might induce UPR through ATF6 and IRE1-XBP1 pathways, but might also modify the outcome to benefit HCV or HCV subreplicon replication.

• The Journal of Advanced Prosthodontics
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• 제7권2호
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• pp.108-114
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• 2015

PURPOSE. The aim of this study was to evaluate effect of different surface treatment methods on the bond strength between aged composite-resin core and luting agent. MATERIALS AND METHODS. Seventy-five resin composites and also seventy-five zirconia ceramic discs were prepared. 60 composite samples were exposed to thermal aging (10,000 cycles, 5 to $55^{\circ}C$) and different surface treatment. All specimens were separated into 5 groups (n=15): 1) Intact specimens 2) Thermal aging-air polishing 3) Thermal aging- Er:YAG laser irradiation 4) Thermal aging- acid etching 5) Thermal-aging. All specimens were bonded to the zirconia discs with resin cement and fixed to universal testing machine and bond strength testing loaded to failure with a crosshead speed of 0.5 mm/min. The fractured surface was classified as adhesive failure, cohesive failure and adhesive-cohesive failure. The bond strength data was statistically compared by the Kruskal-Wallis method complemented by the Bonferroni correction Mann-Whitney U test. The probability level for statistical significance was set at ${\alpha}$=.05. RESULTS. Thermal aging and different surface treatment methods have significant effect on the bond strength between composite-resin cores and luting-agent (P<.05). The mean baseline bond strength values ranged between $7.07{\pm}2.11$ and $26.05{\pm}6.53$ N. The highest bond strength of $26.05{\pm}6.53$ N was obtained with Group 3. Group 5 showed the lowest value of bond strength. CONCLUSION. Appropriate surface treatment method should be applied to aged composite resin cores or aged-composites restorations should be replaced for the optimal bond strength and the clinical success.

• Clinical and Experimental Reproductive Medicine
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• 제27권2호
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• pp.117-131
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• 2000

Objectives: To develop a new immunohistochemical marker system for supplementation of the Noyes histological classification of the endometrium in women of child bearing age with regular menstrual cycles, and to employ this system to evaluate pathologic factors involved in endometriosis, and thus to ascertain if it is useful in diagnosis. Materials and Methods: Endometrial biopsies were sampled from the posterior fundus of 41 (24 proliferative phases, 17 secretory phases) women with regular menstrual cycles (28-32 days), and each sample was immunohistochemically stained according to Noyes et al (1975) for determination of expression for estrogen receptor (ER), progesterone receptor (PR), integrin ${\alpha}_1$, ${\alpha}_4$, ${\beta}_3$, COX-1 and COX-2. Then, the PR, integrin ${\beta}_3$ and COX-2 which were clearly expressed in the luteal phase was with endometrial samples were obtained from 20 cases of normal patients (group 1) and 25 cases with endometriosis (group 2) after confirming the day of ovulation by sex steroid level measurements 7-8 days after ovulation Results: In the regular menstruation group the expression of ER showed a tendency to be increased in the proliferative phase and decreased in the secretory phase, and was the highest in the proliferative phase. However, PR in the stromal cells showed no change in the entire menstrual cycle while in the epithelial cells, PR reached a peak in the late proliferative phase and was almost absent in the secretory phase. Integrin (${\alpha}_1$, ${\alpha}_4$, and ${\beta}_3$ expression in the epithelial cells was absent in the proliferative phase but ${\alpha}_1$ was strongly expressed starting from the early secretory phase into the entire secretory phase. ${\alpha}_4$ was expressed strongly in the early and mid secretory phases and disappeared in the late proliferative phase, while ${\beta}_3$ appeared after the mid secretory phase and continued to be expressed until the late secretory phase. Expression in the stromal cells was weak overall and did not show any cyclic pattern. COX-1 expression was shown as a cyclic pattern in the stromal and epithelial cells and was particularly strongly expressed in the mid secretory phase of epithelial cells, and in the mid secretory and menstruation phase of stromal cells. In the endometrial epithelial cells there was strong expression during the entire cycle with stronger expression in the secretory phase compared to the prolferative phase. COX-2 was clearly expressed in the late proliferative, early and mid secretory phases in the stromal cells. No expression was observed in the proliferative phase of the epithelial cells, but which began to appear in the early secretory phase reaching a significant pattern from the mid secretory phase onwards. There was almost no expression in the stromal cells. In the cases with endometriosis showing normal endometrial maturation according to the Noyes classification, PR expression was increased while Integrin-${\beta}_3$의 expression was significantly decreased compared to the normal group. Also, COX-2 expression was slightly decreased in the stromal cells of patients with endometriosis while it was significantly increased in the stromal cells. Conclusion: Immunohistochemical markers can supplement the original Noyes classification of histological endometrial dating and therefore ascertain existing pathologic conditions. Particularly for patients with endometriosis with normally mature endometrial cells, changes in COX-2 and integrin expression patterns may assist in elucidating pathophysiologic mechanisms and therefore aid in the diagnosis of abnormal implantation conditions, and consequently determine a treatment modality.

• 한국가금학회지
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• 제42권1호
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• pp.51-59
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• 2015

본 연구는 밀사에 의한 환경스트레스가 닭의 품종에 따라 스트레스 및 대사 연관 유전자들의 발현에 어떤 영향을 미치는지 알아보고자 실시하였다. 공시계는 한국재래닭과 백색레그혼으로 두 품종 모두 40주령 때 대조구($540cm^2$/수) 및 고밀도구($311cm^2$/수)로 분리하고, 50주령까지 10주간 사육하였다. 사양시험 종료 후, 각 개체의 간으로부터 total RNA를 추출하고, 스트레스, 소포체(ER) 스트레스 및 대사 연관유전자들의 발현을 real-time PCR을 이용하여 분석하였다. 한국재래계는 분석된 모든 스트레스 표지 유전자들의 발현이 밀사구와 대조구 사이에 유의적인 변화를 보이지 않았다. 그러나 백색레그혼의 경우, HSP70과 $HSP90{\alpha}$ 유전자의 발현이 유의적으로 높게 나타났다(P<0.05). 분석된 ATF6, GRP78, SREBP2 등의 발현은 품종 간 차이를 볼 수 없었지만, XBP1의 경우 백색레그혼이 한국재래계에 비하여 높은 발현을 보였다(P<0.05). 분석된 유전자들 중 FABP4, FATP1, ACSL1 등의 경우, 한국재래계에 비하여 백색레그혼에서 높은 유전자 발현을 보였다(P<0.05). GLUT의 발현은 품종 간에는 영향을 받지 않지만, 밀사에 의한 영향을 받고 있음을 보여주었다. 고밀도사양 체계는 닭의 품종과 관계없이 스트레스 요인이 될 수 있으며, 닭의 품종이나 개량의 정도에 따라 스트레스 반응에 대한 유전적 차이가 있음을 시사하고, 또한 밀사와 같은 환경적 스트레스는 간의 지방 및 포도당 대사에 영향을 미칠 수 있음을 보여주었다.

• 한국식품영양과학회지
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• 제43권1호
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• pp.24-29
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• 2014

본 연구는 구기자와 구기엽 추출물이 난소를 절제한 흰쥐의 체중 증가, 골밀도, 에스트로겐 수용체의 발현에 미치는 영향을 밝히고자 시행하였다. 실험군은 흰쥐 24마리를 가장수술군(Sham군), 난소를 절제한 대조군(OVX군), 난소절제 후 구기자 추출액을 투여한 군(LCF군), 난소절제 후 구기엽 추출액을 투여한 군(LCL군)으로 구분하였다. 8주 후 난소를 절제한 OVX군($330{\pm}5.39g$), LCF군($315{\pm}2.99g$) 및 LCL군($318{\pm}2.06g$)의 체중은 Sham군($281{\pm}1.71g$)에 비하여 증가하였다. 혈청 osteocalcin 활성은 OVX군($107{\pm}3.52ng/mL$)에 비하여 LCF군($444.6{\pm}26.9ng/mL$)과 LCL군($407{\pm}18.9ng/mL$)에서 증가하였다. Alkaline phosphatase의 활성은 OVX군($95{\pm}2.9U/L$)에 비하여 LCF군($108{\pm}2.7U/L$)과 LCL군($407{\pm}18.9ng/mL$)에서 증가하였다. 8주 후 넙다리뼈를 실체현미경으로 관찰한 결과 뼈 기질밀도는 난소절제군에서 감소하였으나, 구기자와 구기엽을 추출액을 투여한 군에서는 뚜렷이 회복되었다. 에스트로겐 수용체의 mRNA 발현은 OVX군에서는 거의 발현되지 않았으나, LCF군과 LCL군에서 뚜렷이 증가하였다. 이상의 결과로 보아 구기자와 구기엽 물추출물이 난소절제에 의하여 유발된 흰쥐의 뼈 기질 회복 또는 손실 지연에 효과가 있다고 할 수 있을 것이다.

• Clinical and Experimental Reproductive Medicine
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• 제36권2호
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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.

• 한국재료학회:학술대회논문집
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• 한국재료학회 1994년도 추계 학술발표 강연 및 논문 개요집
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• pp.1-1
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• 1994

;The electronic state calculations for various types of ceramic materials have beell performed by the use of $DV-X\;{\alpha}$ cluster method. The molecular orbital levels and wave functions for model clusters have been computed to study the electronic properties ami chemical bonding of the ceramics. For ${\beta}-sialon(Si_{6-z}Al_zO_zN_{8-z})$ which is a high temperature structural material based on ${\beta}-Si_3N_4$, we have made model cluster calculations to estimate the strength of chemical bonding between atoms by the Mulliken population analysis. It is found that the covalent bonding between Si and N atoms is very strong in pure ${\beta}-Si_3N_4$, but the covalency around solute atom is considerably weakened when Si atom is substituted by AI. This tendency is enhanced by an additional substitution of oxygen atom for N. The result calculated can well explain the experimental data of changes in mechanical properties such as the reductions of Young's modulus and Vickers hardness with increment of z-value in ${\beta}-sialon$. Various model clusters for transition metal oxides which show many interesting physical and chemical properties have also been calculated. High-valent perovskite-type iron oxides EMFe0_3E(M=Ca and Sr) possess very interesting magnetic and chemical properties. In these oxides, iron exists as $Fe^{4+}$ state, but the experimental measurement of Mossba~er effect suggests that disproportionation $2Fe^{4+}=Fe^{3+}+Fe^{5+}$ takes place for $CaFe0_3$ at low temperatures. The model cluster calculations for these compounds indicated the existence of considerably strong covalent bonding of Fe-O. The calculations of hyperfine interaction at iron neucleus show very good agreement with the experimental Mossbauer measurements. The result calculated also implies that the disproportionation reaction is strongly possible by assuming the quenching of breathing phonon mode at low temperatures.tures.

• Asian-Australasian Journal of Animal Sciences
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• 제22권11호
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• pp.1495-1503
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• 2009

This experiment was conducted to determine the effect of dietary supplementation with BCAA (branched-chain amino acids: leucine, isoleucine and valine) on improving the growth of rats in a malnutritional IUGR (Intrauterine Growth Retardation) model, which was established by feeding restriction. In the experimental treatment, rats were fed purified diets supplemented with BCAA (mixed) during the whole gestation period, while arginine and alanine supplementation were set as the positive and negative control group, respectively. The results showed that, compared to the effect of alanine, BCAA reversed IUGR by increasing the fetus weights by 18.4% and placental weights by 18.0% while fetal numbers were statistically increased. Analysis of gene and protein expression revealed that BCAA treatment increased embryonic liver IGF-I expression; the uterus expressed higher levels of estrogen receptor-$\alpha$ (ER-$\alpha$) and progesterone receptor (PR), and the placenta expressed higher levels of IGF-II. Amino acid analysis of dam plasma revealed that BCAA supplementation effectively enhanced the plasma BCAA levels caused by the feed restriction. BCAA also enhanced the embryonic liver gluconeogenesis by augmenting the expression of two key enzymes, namely fructose-1,6-biphosphatase (FBP) and phosphoenolpyruvate carboxykinase (PEPCK). In conclusion, supplementation of BCAA increased litter size, embryonic weight and litter embryonic weight by improving the dam uterus and placental functions as well as increasing gluconeogenesis in the embryonic liver, which further provided energy to enhance the embryonic growth.

• 대한치과기공학회지
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• 제31권4호
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• pp.37-43
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• 2009

This study evaluated the effect of concentration of glass fiber reinforcement on the flexural properties of auto and heat polymerized denture base resin. The test specimens($64{\times}10{\times}3.3mm$) were made of auto and heat polymerized resin(Vertex, Dentimax, Netherlands). Glass fiber(ER 270FW, Hankuk Fiber Glass, Korea) were used to reinforce the denture base resin. The 2.6%, 5.3% and 7.9% volume pre-impregnated fiber were located at the bottom of specimen. The test specimens(n=7) of each group were stored in distilled water at $37^{\circ}C$ for 50 hours before test. The flexural strength and modulus were measured by an universal testing machine(Z020, Zwick, Germany) at a crosshead speed of 5 mm/min in a three-point bending mode. The data was analyzed by one-way ANOVA and the Duncan's multiple range test(${\alpha}$=0.05). The difference of auto polymerized resin groups and heat polymerized resin groups were statistically analyzed by t-test(${\alpha}$=0.05). Glass fiber showed significant reinforcing effects on auto and heat polymerized resin. For flexural strength and modulus, auto polymerized resin was the highest in 7.9% volume, while heat polymerized resin was the highest in 5.3% volume. In this study, glass fiber at 7.9% volume ratio showed most effective reinforcing effect on auto polymerized resin and glass fiber at 5.3% volume ratio showed most effective reinforcing effect on heat polymerized resin in terms of flexural strength and flexural modulus.

• BMB Reports
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• 제36권1호
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• pp.28-34
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• 2003

Breast cancer is the most prevalent cancer among women in Western countries, and its prevalence is also increasing in Asia. The major risk factor for breast cancer can be traced to reproductive events that influence the lifetime levels of hormones. However, a large percentage of breast cancer cases cannot, be explained by these risk factors. The identification of susceptibility factors that predispose individuals to breast cancer (for instance, if they are exposed to particular environmental agents) could possibly give further insight into the etiology of this malignancy and provide targets for the future development of therapeutics. The most interesting candidate genes include those that mediate a range of functions. These include carcinogen metabolism, DNA repair, steroid hormone metabolism, signal transduction, and cell cycle control. We conducted a hospital-based case-control study in South Korea to evaluate the potential modifying role of the genetic polymorphisms of selected low penetrance genes that are involved in carcinogen metabolisms (i.e., CYP1A1, CYP2E1, GSTM1/T1/P1, NAT1/2, etc.), estrogen synthesis and metabolism (i.e., CYP19, CYP17, CYP1B1, COMT, ER-$\alpha$, etc.), DNA repair (i.e., XRCC1/3, ERCC2/4, ATM, AGT, etc.), and signal transduction as well as others (i.e., TGF-$\beta$, IGF-1, TNF-$\beta$, IL-1B, IL-1RN, etc.). We also took into account the potential interaction between these and the known risk factors of breast cancer. The results of selected genes will be presented in this mini-review.