Structural Integrity Evaluation of Steam Generator Tube with Two Parallel Axial Through-Wall Cracks

Moon Seong In,Kim Young Jin,Lee Jin Ho,Song Myung Ho,Park Youn Won Korean Nuclear Society 2004 Nuclear Engineering and Technology Vol.36 No.4

It is commonly required that tubes with defects exceeding $40\%$ of wall thickness in depth should be plugged; however, this criterion is too conservative for some locations and for some types of defects. Many studies have been done with the aim of developing an alternative plugging criteria, and these studies have shown that steam generator tubes with a certain range of axial through-wall cracks could remain in service without any safety or reliability problems. However, these studies have been limited, thus far, to consideration of single cracked tubes, necessitating a study on multiple cracks, which are commonly found. A crack coalescence model applicable to steam generator tubes with two collinear axial through-wall cracks was proposed in the previous study. In this paper, the investigation is extended to the parallel axial cracks spaced in a circumferential direction, because parallel axial cracks are more frequently detected during in-service inspections than collinear axial cracks. Interaction effects between two parallel cracks are evaluated by performing elastic and elastic-plastic finite element analyses.

DMBA 유도 햄스터 협낭암 발생과정에서 방사선 조사가 증식세포핵항원(PCNA)의 발현과 apoptosis 유발에 미치는 영향

전인성,허민석,최항문,이삼선,최순철 대한구강악안면방사선학회 2000 Imaging Science in Dentistry Vol.30 No.3

Purpose : This study was carried out to investigate the effect of irradiation on the expression of proliferating cell nuclear antigen (PCNA) and apoptosis induction during the carcinogenesis in hamster buccal pouch. Materials and methods : Three months old Syrian golden hamsters were divided into control and 2 experimental groups, Hamsters in control group were left untreated on buccal pouchs. Twenty four hamsters were treated with 0.5% DMBA tri-weekly on the right buccal pouch. Forty eight hamsters were treated with 0.5% DMBA tri-weekly and irradiated with the dose of 5 Gy and 10 Gy at 6,9, 12, 15 weeks after DMBA application. Resected buccal pouches were sectioned and examined for potential expression pattern of PCNA and apoptosis. Results : The PCNA index was increased with the stages of buccal pouch epithelium carcinogenesis except the hyperplasia stage in control group (p< 0.05). The irradiation did not effect on the PCNA index in the dysplasia and the carcinoma in situ stage, but in the hyperplasia stage, the PCNA index was increased with 10 Gy radiation and decreased in the carcinoma stage (p< 0.05). The apoptotic index was significantly decreased from the carcinoma in situ stage and the lowest in the carcinoma stage, The apoptotic index was significantly decreased in the hyperplasia and dysplasia stage with the 5 Gy irradiation and significantly increased only in the carcinoma stage with the 10 Gy irradiation (p< 0.05). Conclusion : The PCNA and apoptotic index were varied according to the irradiation period and dosage in each carcinogenesis stage. (Korean J Oral Maxillofac Radiol 2000; 30: 207-216)

백서 뇌하수체 성장호르몬 종양세포의 Chicken Lysozyme 유전자 갑상선호르몬 반응요소에서 갑상선호르몬 수용체 역동학에 미치는 T₃효과 분석

이성진,박철영,정인경,홍은경,최철수,김현규,김두만,유재명,임성희,최문기,유형준,박성우,Larsen, P. Reed 대한내분비학회 2003 Endocrinology and metabolism Vol.18 No.4

연구배경: 유전자 전사과정은 증강부위 (enhancer) 또는 억제부위(silencer)의 복합작용을 통하여 조절되며 chicken Iysozyme 유전자의 억제부위는 두 개의독립적인 전사인자 결합부위 (Fl과 F2)를 가지는데 Fl부위는 75~93 kD 크기의 NePl 단백질이 결합하는 위치인 반면 역위회문구조(inverted palindrome, InvPal)의 F2 부위는 갑상선호르몬 수용체가 결합하는 갑상선호르몬 반응요소인 동시에 갑상선호르몬 수용체에 대해 높은 친화력을 가지고 있다. 실험적으로 Fl부위 또는 F2 부위 (이하 F2-TRE 부위)를 각각 다량체화(multimerization) 하였을 때 전사억제효과가 증가하였다는 연구 결과는 Fl 부위와 F2-TRE 부위가 서로 독립적으로 기능하는 구조임을 시사하고 있으며chicken Iysozyme 유전자의 억제부위가 완전한 전사억제효과를 가지기 위해서는 Fl 부위와 F2-TRE 부위가 모두 필요함이 보고 되어 있다. 현재 갑상선호르몬에 의한 chicken Iysozyme 유전자 조절기전을 규명하기 위해 많은 연구가 이루어지고 있으나 73 자극 전 ·후 갑상선호르몬 수용체의 역동학에 대해서는 아직까지 거의 보고된 바 없으며 이와 관련하여 저자들은 치근 사람의 간암세포주인 HepG2 세포에서 T₃ 자극전 ·후 갑상선호르몬 반응요소인 IRE2 부위에 대한 갑상선호르몬 수용체의 결합이 교대로 이루어지고 있음을 염색체 면역침전법 (chromatin immunoprecipitation, ChIP) 및 정량적 중합효소연쇄반응을 이용하여 확인한 바 있다. 이에 저자들은 본 연구에서 F2-lRE 부위를 포함하는 백서 뇌하수체 종양세포주인 GC8 세포를대상으로 염색체 면역침전법과 중합효소연쇄반응을 이용하여 갑상선호르몬 자극 전 후 시간적 순서에 따라 F2-TRE 부위에 결합하는 갑상선호르몬 수용체의 결합양상 변화를 분석함으로써 갑상선호르몬 수용체의 역동학적 모델을 제시하여 보고자 하였다. 방법: thymidine kinase(TK) promoter의 5' 부위에 chicken Iysozyme silencer의 고친화력 갑상선호르몬 반응요소(F2-TRE 부위)가 삽입된 플라스미드,mouse TRα gene이 삽입된 플라스미드, neomycinresistance gene이 삽입된 플라스미드를 백서 뇌하수체성장호르몬 종양세포인 GC 세포에 각각 주입하여 제작한 GC8 세포주를 사용하였다. 100 αM T₃를 투여하기 전과 투여한 후 12시간 뒤 TRαl, TRβl, TRβ2 항체를 이용하여 염색체 면역침전법과 고식적 중합효소연쇄반응 및 정량적 중합효소연쇄반응을 시행하였다. 각 갑상선호르몬 수용체 항체의 양을 1.5μL에서 4.5μL로 바꾸어 첨가한 후 동일한 방법으로 염색체 면역침전법을 반복하여 시행하였다. 100nM T₃를 투여하기전과 투여한 후 20분, 1시간, 2시간, 4시간, 6시간, 8시간, 12시간 뒤 TRαl, TRβl, TRβ2 항체를 이용하여 염색체 면역침전법을 시행하였다. 100nM T₃를 투여하기 전과 투여한 후 12시간 뒤 TRαl, TRβl, TRβ2 단백질의 발현량을 알아보고자 Western blot을 시행하였다. 결과: 100 nM T₃를 투여하기 전과 투여한 후 12시간 뒤 염색체 면역침전법과 F2-TRE 시발체를 이용한 고식적 중합효소연쇄반응을 시행하였을 때 T₃를 투여한 후 12시간 뒤 TRα1과 TRβ2의 결합은 증가한 반면 TRβl의 결합은 감소하였다. 정량적 중합효소연쇄반응으로 갑상선호르몬 수용체의 결합량을 측정하였을 때TRα1은 T₃ 투여 전 1.01에서 T₃ 투여 후 2.73으로 유의하게 증가하였으며 TBβl은 T₃ 투여 전 4.59에서 T₃투여 후 2.06으로 유의하게 감소하였고 TRβ2는 T₃ 투여 전 2.53에서 T₃ 투여 후 2.98로 증가하는 경향을보였다(TRα1, Δ=+170.3%, p<0.05; TRαl, Δ=-55.1%, p<0.05; TRβ2, Δ=+17.8%). 정량적 중합효소연쇄반응으로 측정한 갑상선호르몬 수용체의 전체 결합량은 T₃ 투여 전 8.13에서 T₃ 투여 후 7.77로 감소하였으나 통계적으로 유의하지 않았다(Δ=-4.4%).100nM T₃ 투여 전 ·후 시간별로 염색체 면역침전법과 정량적 중합효소연쇄반응을 시행하였을 때 TRα1 결합량은 T₃ 투여 후 20분과 6시간 뒤 각각 증가하였으며 TRβ2 결합량은 T₃ 투여 후 20분 뒤 최고치까지 증가하였다가 2시간 뒤부터 감소하였다. 그러나 TRαl 결합량은 T₃ 투여 후 1시간 뒤 최저치까지 감소되었다가 이후 지속적으로 유지되는 경향을 보였다. 100 nM T₃ 투여 전과 투여 후 2시간 뒤 갑상선호르몬 수용체의 결합량을 비교하였을 때 TRα1은 219.8% (1.01→3.23), TRβ2는 9.9% (2.53→2.78) 증가하였으나 TRβ1은 52.9% (4.59-)2.16) 감소하였으며 결합량 변화의 방향은 100 naM T₃ 투여 후 4시간 뒤와 6시간 뒤 갑상선호르몬 수용체 결합량 변화의 방향과 일치하였다(TRα1, 2.89→4.09, Δ =+41.5%; TRβl, 2.33→2.04, Δ=-12.4%; TRβ2, 2.57→2.59, Δ=10.8%). 갑상선호르몬 수용체 항체를 1.5 μL 또는 4.5 μL 투여한 후 F2-TRE부위에 대한 염색체 면역침전법 및 정량적 중합효소연쇄반응을 각각 시행하였을 때 첨가한 갑상선호르몬 수용체 항체의 양에 따른 갑상선호르몬 수용체결합량의 유의한 차이는 없었다. 100 nM T₃를 투여하기 전과 투여한 후 12시간 뒤 Western blot을 시행하였을 때 갑상선호르몬 수용체 발현량의 유의한 차이는 관찰되지 않았다. 결론: 본 연구에서 관찰된 T₃ 자극 전 · 후 chickenIysozyme 유전자의 F2-TBtE 부위에 대한 갑상선호르몬 수용체 이성체의 교대현상 및 시간적 순서에 따른 갑상선호르몬 수용체 결합양상의 변화가 나타내는 의미에 대하여 추시 연구가 필요함은 물론 추가적으로 다른 유전자 또는 다른 종류의 세포주를 대상으로 T₃자극에 따른 갑상선호르몬 수용체 결합양상의 변화와유전자 발현을 검토하여야 할 것이다. 한편 본 연구 결과만으로는 갑상선호르몬 수용체 역동학에 대한 많은 의문점을 풀 수 없음에도 불구하고 아직까지 국내외적으로 갑상선호르몬 수용체의 역동학에 대한 연구 결과가 거의 없는 현실을 고려하여 볼 때 본 연구는 제한적이나마 일정한 농도의 갑상선호르몬 자극 전ㆍ후chicken Iysozyme 유전자의 F2-TRE 부위에서 갑상선호르몬 수용체의 교대현상을 재확인하였다는 점과 갑상선호르몬 자극 전 · 후 시간적 순서에 따른 갑상선호르몬 수용체의 역동학적 모델을 처음으로 제시하였다는 점에서 의의가 있을 것으로 생각된다. Background: The regulation of gene transcription can be controlled by both positive (enhancer) and negative (silencer) regulatory sequences. Several enhancer and silencer elements have been described in the 5' region of the chicken lysozyme gene. The silencer located at -2.4 kb upstream of the chicken lysozyme gene is composed of two separate modules (Fl and F2) that can function as silencers by themselves, but also show synergistic repression after multimerization. The F1 module is bound by a protein termed NePl and F2 module, a F2 thyroid hormone response element (F2-TRE), and can be bound by the thyroid hormone receptor (TR). F2-TRE has an inverted palindromic structure, with high affinity to TR. Although many current reported results have tried to explain the regulatory mechanism of chicken lysozyme gene expression due to the thyroid hormone, there have been few studies that clarify the TR dynamics in the F2-TRE of the chicken lysozyme gene, either with or without exposure of the thyroid hormone. Here, the changes in the TR binding patterns in the F2-TRE of the chicken lysozyme gene are described, both before and after T₃ stimulation over time. Methods: Using the stably transfected rat pituitary somatotroph tumor cell line, GC8 cells, with the F2-TRE inserted 5' to the thymidine kinase (TIC) promoter, together with a mouse TRα - expressing plasmid, a chromatin immunoprecipitation (ChIP) technique was employed to reveal the TR-TRE interaction before and after T₃ stimulation. Following the cross-linking and sonication of the cells, the immunoprecipitation was performed overnight, at 4℃, with TRαl, TRβl and TRβ2 antibodies, respectively. The binding patterns and amounts of TRαl, TRβ1 and TRβ2 to the F2-TRE, before and after 12 hours of 100nM T₃ stimulation, were analyzed using conventional and quantitative real-time polymerase chain reactions (RQ-PCR). The ChIP technique was used to give a basal value for 20 minutes and 1, 2, 4, 6, 8 and 12 hours after the 100nM T₃ stimulation, and RQ-PCR was then performed. Western blot with TRαl, TRβl and TRβ2 antibodies were also performed. Results: After 12 hours of 100 nM T₃ stimulation of the GC8 cells, the TRα1 and TRβ2 binding to the F2-TRE increased, but the TRβ1 binding to the F2-TRE decreased, by conventional PCR. Although all the TR isoforms were bound to the F2-TRE by RQ-PCR, the TRαl binding to the F2-TRE, after 12 hours of l00nM T₃ stimulation, was significantly increased (1.01→2.73, Δ =+170.3%, p<0.05), but the change in the amount of TW2 binding was not significant (2.53→2.98, Δ=+17.8%). The TRβl binding was significantly decreased compared with that of the basal level (4.59→2.06, Δ=-55.1%, p<0.05). The total TR bindings to the F2-TRE had a tendency to decrease after 12 hours of 100 nM T₃ stimulation (8.13→7.77, Δ=-4.4%). The binding patterns and amounts of TRαl, Tβl and Tβ2, both before and after the 100 nM T₃ stimulation, were also identified over time. While the TRβl bindings to the F2-TRE after 1 hour of l00nM T₃ stimulation were acutely reduced, those of the TRαl at 20 minutes and 6 hours were increased. The TRβ2 bindings showed a maximal increase at 20 minutes. The directions of the TR binding patterns, between the before and after 2 hours of 100nM T₃ stimulation, were identical to those for between 4 and 6 hours of T₃ stimulation. There was no significant difference in the TR bindings to the F2-TRE in relation to the amounts (1.5 vs. 4.5μ I) of TR antibodies used during the ChIP assays. The Western blots showed no significant change of the levels of each TR isoform proteins, either before or after 12 hours of exposure to 100nM T₃. Conclusion: These results show the dynamic binding patterns of the TR isoforms to the F2-TRE of the chicken lysozyme gene, both before and after T₃ stimulation, over time. Further investigation, however, will be needed to clarify the mechanisms of our observations. The ChIP technique may then be used to reveal the dynamic models of the cofactors, as well as TR isoforms, in the TR-regulated transcription machinery (J Kor SOC Endocrinol 18:379-391, 2003).

제1형 탈요오드효소 유전자 갑상선호르몬 반응요소에서 T₃자극에 따른 갑상선호르몬 수용체 역동학 모델

이성진,박철영,정인경,홍은경,최철수,김현규,김두만,유재명,임성희,최문기,유형준,박성우,Larsen, P. Reed 대한내분비학회 2003 Endocrinology and metabolism Vol.18 No.3

연구배경: 제1형 탈요오드효소의 발현에 관여하는 hdiol 유전자는 5 flanking region 내 서로 다른 특성을 가진 두 종류의 갑상선호르몬 반응요소, 즉 TREI과 TRE2를 가지고 있음이 알려져 있다. 사람의 간암세포주인 HepG2 세포에서 T₃를 투여하였을 때 hdiol유전자의 전사작용이 급격하게 증가하는데 hdiol mRNA가 충분히 발현하기 위해서는 두 종류의 갑상선호르몬 반응요소가 모두 필요함이 보고 되어 있으나 T₃ 투여시 갑상선호르몬 반응요소와 결합하는 갑상선호르몬 수용체의 역동학에 대해서는 아직까지 연구된바 없다. 한편 현재까지 보고 된 연구 결과들은 갑상선호르몬 자극이 없더라도 갑상선호르몬 수용체와 갑상선호르몬 반응요소가 서로 지속적으로 상호작용 한다는 전제 조건을 바탕으로 하고 있는데 아직까지 이러한 가정은 간접적으로만 증명되어 있는 상태이다. 이에 저자들은 본 연구에서 사람의 간암세포주인 HepG2세포를 대상으로 염색체 면역침전법과 중합효소연쇄반응을 이용하여 갑상선호르몬 자극 전·후 hdiol 유전자의 갑상선호르몬 반응요소에 결합하는 갑상선호르몬 수용체의 결합양상 변화를 분석함과 동시에 갑상선호르몬 자극 전에도 갑상선호르몬 수용체와 갑상선호르몬 반응요소가 서로 결합된 상태로 존재함을 직접적으로 확인하고자 하였다. 방법: 사람의 간암세포주인 HepG2 세포를 대상으로 100 nM T₃를 투여하기 전과 투여한 후 12시간 뒤 TRα1, TR 1, TR 2 항체와 IREI, TRE2에 상보적인 시발체를 이용하여 염색체 면역침전법과 고식적 중합효소연쇄반응 및 정량적 중합효소연쇄반응을 시행하였다. 100nM T₃를 투여하기 전과 투여한 후 12시간 뒤 hdiol mRNA 발현량의 변화를 정량적으로 측정하기 위하여 역전사 중합효소연쇄반응을 시행하였다. 100 nM T₃를 투여하기 전과 투여한 후 12시간 뒤 TR4'1, TR 1, TR 2 단백질의 발현량을 알아보고자Western blot을 시행하였다. 결과: 100 nM T₃를 투여하기 전과 투여한 후 12시간 뒤 염색체 면역침전법과 TREI 시발체를 이용한 고식적 중합효소연쇄반응을 시행하였을 때 T₃ 투여 전후 TREI 부위에는 TRgl이 결합하였으며 T₃를 투여한 후 TRal 결합이 감소하였다. 정량적 중합효소연쇄반응으로 TR4'1 결합량을 측정하였을 때 T₃ 투여 전3.74에서 T₃ 투여 후 1.97로 감소하여 통계적으로 유의한 차이를 나타내었다(Δ=-47.3%, p<0.05). T₃ 투여 전 ·후 TRβl과 TRβ2의 결합은 관찰되지 않았다. 100 nM T₃를 투여하기 전과 투여한 후 12시간 뒤 염색체 면역침전법과 TRE2 시발체를 이용한 고식적 중합효소연쇄반응을 시god하였을 때 T₃ 투여 전ㆍ후 TRE2 부위에는 TRα1, TR 1, TR 2가 모두 결합하였으며 T₃를 투여한 후 TRα1과 TR 1의 결합은 감소하였으나 TR 2의 결합은 증가하였다. 정량적 중합효소연쇄반응으로 갑상선호르몬 수용체의 결합량을 측정하였을 때 TRαl은 T₃ 투여 전 10.41에서 T₃ 투여 후 3.01, TRβl은 T₃ 투여 전 12.56에서 T₃ 투여 후 2.93으로 유의하게 감소하였으며 TRβ2는 T₃ 투여 전 9.17에서 T₃ 투여 후 9.84로 증가하는 경향을 보였다(TRα1, Δ=-71.1%, p<0.05; TR 1, Δ=-76.7%, p<0.05; TR2, Δ=+7.3%). 정량적 중합효소연쇄반응으로 측정한 갑상선호르몬 수용체의 전체 결합량은 T₃ 투여 전 32.14에서 T₃ 투여 후 15.78로 감소하여 통계적으로 유의한 차이를 나타내었다(Δ=-50.9%, p.0.05). 갑상선호르몬 수용체 항체를 1.5μL와 4.5μL 첨가한 후TREI과 TRE2에 대하여 염색체 면역침전법 및 정량적 중합효소연쇄반응을 각각 시깡하였을 때 첨가한 갑상선호르몬 수용체 항체의 양에 따른 갑상선호르몬 수용체 결합량의 차이는 없었다. 100 nM T₃를 투여하기전과 투여란 후 12시간 뒤 역전사 중합효소연쇄반응 및 hdiol cDNA 시발체를 이용한 정량적 중합효소연쇄반응을 시행하였을 때 T₃를 투여한 후 hdiol mRNA발현량은 2.03배 증가하였다(p<0.001). 100 nM T₃를 투여하기 전과 투여한 후 12시간 뒤 Western blot을 시행하였을 때 갑상선호르몬 수용체 발현량은 유의한 차이가 없었다. 결론: 현재까지 갑상선호르몬 수용체의 역동학에 대한 연구가거의 이루어지지 않았던 실정을고려하여볼 때 본 연구는 제한적이나마 일정한 농도의 갑상선호르몬 자극 전 · 후 갑상선호르몬 수용체 결합양상의 변화, 특히 T₃ 자극 전 hdiol 유전자의 TREI 부위에서 TRal이 억제자 (silencer)로서 작용할 가능성 및 T₃자극 전 · 투 TRE2 부위에서 갑상선호르몬 수용체 교대현상을 처음으로 제시하였다는 점에서 의의가 있으며 향후 다른 종류의 세포주 및 체내에서 갑상선호르몬 자극 전 후 갑상선호르몬 수용체 결합양상의 변화 및 유전자 발현에 미치는 영향을 연구할 필요가 있으리라 생각된다. 한편 염색체 면역침전법을 통해 HepG2 세포에서 T₃ 자극이 없더라도 갑상선호르몬 수용체와 갑상선호르몬 반응요소 사이에 지속적인 상호작용이 존재할 뿐 아니라 갑상선호르몬 반응요소에 대한 갑상선호르몬 수용체의 결합이 교대로 이루어지고 있음을 직접적으로 확인할 수 있었으며 향후 T₃ 자극 전 · 후 갑상선호르몬 수용체를 통한 유전자 전사조절기전에 관여하는 전사인자와 역동학적 기전을 규명함에 있어서 염색체 면역침전법과 정량적 중합효소연쇄반응이 매우 유용하게 이용될 수 있을 것이다. Background: Type 1 iodothyronine deiodinase (Dl), the product of the hdiol gene, is involved in thyroid hormone activation by the deiodination of thyroxine (T4) to form 3,5,3'-triiodothyronine (T3). Recent studies have identified two thyroid hormone response elements (TREs) in the 5 ' flanking region of the hdiol gene. TRE1, proximal to TRE in the hdiol gene, consists of a direct repeat of thyroid hormone receptor (TR) binding octamers with 10 bp separating the two TR binding sites. The upstream TRE, TRE2, is a classical direct repeat of retinoid X receptor (RXR)/TR binding half-sites with a 4-bp separation. There are few studies clarifying the TR dynamics in the TRE of a specific gene with or without the exposure of activated thyroid hormone. We evaluated TR binding patterns in the proximal and distal TREs of the hdiol gene before and after T₃ stimulation. Methods: We employed chromatin immunoprecipitation (ChIP) technique to investigate the TR- TRE interaction before and after T₃ stimulation in human hepatocellular carcinoma HepG2 cell line. Following cross-linking and sonication of the cells, immunoprecipitation was performed overnight at 4℃ with TRαl, TRβ1 and TRβ2 antibodies. We analyzed the binding patterns and amounts of TRαl, TRβl and TRβ2 to TREl and TRE2 before and after 12 hours stimulation with 100 nM T3 by using conventional and quantitative real-time polymerase chain reactions (RQ-PCR). Reverse transcriptional PCR (RT-PCR) and Western blot with TR 1, TR 1 and TR 2 antibodies were performed to measure the levels of hdiol mRNA and TR 1, TR 1 and TR 2 proteins before and after 12 hours exposure to l00nM T3. Results: In TRE1, TRαl binding was significantly decreased after 12 hours stimulation with l00nM T3 (3.74→97, Δ=-47.3%, p<0.05), but TRβ1 and TRβ2 bindings were not detected by conventional PCR and RQ-PCR. Although all TR isoforms were bound to TRE2, the binding patterns were quite different. While TRα1 and TRβ1 bindings to TRE2 after 12 hours stimulation with 100 nM T3 were significantly decreased (10.41→3.01, Δ=-71.1%, p<0.05; 12.56 →2.93, Δ =-76.7%, p<0.05, respectively), TRβ2 binding was increased but not significantly (9.17 →9.84, Δ =+7.3%). Total TR bindings in TRE2 were significantly decreased after 12 hours stimulation with 1OOnM T₃ (32.14 →15.78, Δ=-50.9%, p<0.05). The TR bindings to TREl and TRE2 were not significantly different by the amounts of TR antibodies used during ChIP assays. The levels of hdiol mRNA were significantly increased, 2.03 times, after 12 hours exposure to l00nM T3 (p<O.001). Western blot showed no significant change of the level of each TR isoform protein before and after 12 hours exposure to 100nM T3. Conclusion: Our results demonstrate the dynamics of TRal at proximal TRE (TRE1) and the switching phenomenon of TR isoforms at distal TRE (TRE2) of the hdiol gene after T3 stimulation. Further investigation, however, is needed to clarify the mechanisms of these observations (J Kor SOC Endocrinol 18:283-295, 2003).

Nelumbinis Semen Reverses a Decrease in $5-HT_{1A}$Receptor Binding Induced by Chronic Mild Stress, a Depression-like Symptom

Jang, Choon-Gon,Kang, Moon-Kyu,Cho, Jae-Han,Lee, Sun-Bok,Kim, Hyun-Taek,Park, Soon-Kwon,Lee, Jin-Woo,Park, Seong-Kyu,Hong, Moo-Chang,Shin, Min-Kyu,Shim, In-Sup,Bae , Hyun-Su The Pharmaceutical Society of Korea 2004 Archives of Pharmacal Research Vol.27 No.10

Depression is associated with a dysfunctional serotonin (5-hydroxytryptamine; 5-HT) system. More recently, several lines of evidence suggest that an important factor in the development of depression may be a deficit in the function and expression of $5-HT_{1A}$ receptors. The present study assessed if Nelumbinis Semen (N. s.) had an anti-depression effect through reversing a decrease in $5-HT_{1A}$receptor binding in rats with depression-like symptoms induced by chronic mild stress. Using a $5-HT_{1A}$ receptor binding assay, with a specific $5-HT_{1A}$receptor agonist, 8- OH-DPAT (8-hydroxy-2-(di-n-propylamino) tetralin), the mechanism of the anti-depression effect of N. s. on rats was investigated, and the effects compared with two well-known antidepressants, Hyperium Perforatum (St. Johns Wort) and fluoxetine (Prozac). Animals were divided into five groups: the normal (N) group without chronic mild stress (CMS), the control (C) group under CMS for 8 weeks, the Nelumbinis Semen (N. s.) treatment group under CMS for 8 weeks, the Hyperium Perforatum (H. p.) treatment group under CMS for 8 weeks and finally, the fluoxetine (F) treatment group under CMS for 8 weeks. Each treatment was administered to rats during the last 4 weeks of the 8-week CMS. A sucrose intake test was performed to test the anti-depression effect of N. s. The N. s. treatment significantly reversed the decreased sucrose intake under CMS (P<0.05 compared to control group under CMS). In the CA2 and CA3 regions of the hippocampus, both N. s. and H. p. reversed the CMS-induced decrease in $5-HT_{1A}$receptor binding. In the I to II regions of the frontal cortex, N. s. and H. p. also reversed the CMS-induced decrease in$5-HT_{1A}$receptor binding, and even showed a significant increase in $5-HT_{1A}$receptor binding compared to the F treatment group (N. s. vs. P, p<0.05, H. p. vs. P, p<0.05). However, in the hypothalamus, all treatments reversed the CMSinduced decrease in $5-HT_{1A}$receptor binding. This reversal effect of N. s. on the decrease in $5-HT_{1A}$receptor binding in the frontal cortex, hippocampus and hypothalamus of rat brains was very similar to that of H. p, but different from that of F. It is concluded that N. s. presents an anti-depression effect through enhancing $5-HT_{1A}$receptor binding.

법랑모세포 분화와 성숙과정에서 OD314의 발현

박주철,안성민,김흥중,정문진,박민주,신인철,손호현 大韓齒科保存學會 2005 Restorative Dentistry & Endodontics Vol.30 No.5

법랑모세포는 법랑질을 형성하고 유지하는 세포로, 법랑질의 유기기질을 분비하고 법랑질 석회화 과정에도 관여한다. 치아 발생과정에서 법랑모세포의 분화는 순차적인 상피-간엽 상호작용에 의하여 조절되나, 분화나 성숙과정의 정확한 기전은 아직까지 잘 알려져 있지 않다. 최근에 상아모세포에서 처음 발견된 OD314가 치아 발생과정에서 상아질을 형성하는 상아모세포 뿐 아니라 법랑모세포에도 발현된다고 하였다. 이에 본 연구에서는 생쥐 하악 전치의 다양한 시기의 법랑모세포를 이용하여, 형태학적 분석과 in-situ hybridization에 의한 OD314 mRNA의 발현 그리고 OD314 항체를 이용한 면역조직화학적 분석을 통하여 OD314 유전자의 법랑 모세포 분화와 성숙과정에서의 역할을 연구하여 다음과 같은 결과를 얻었다. 1. 형태학적으로 법랑모세포는 분화 단계에 따라 분비 전단계 법랑모세포, 분비기 법랑모세포, 성숙기의 평탄끝 법랑모세포와 성숙기의 주름끝 법랑모세포로 구분되었다. 2. OD314 mRNA는 분비기의 법랑모세포에서부터 발현되기 시작하여 법랑모세포가 성숙해갈 수록 그 발현이 증가하였다. 3. OD314 단백질은 분비 전단계의 법랑모세포에서는 발현되지 않고, 분비기의 법랑모세포에서는 세포질에 전체적으로 발현되었다. 성숙기의 평탄끝 법랑모세포와 주름끝 법랑모세포에서는 세포의 근심과 원심끝단에 OD314 단백질이 강하게 발현되었다. 이상의 결과를 종합하여 OD314는 법랑모세포의 분화와 성숙과정에서 세포질 내부에서 특징적인 역할을 하는 것으로 사료된다. Ameloblasts are responsible for the formation and maintenance of enamel which is an epithelially derived protective covering for teeth. Ameloblast differentiation is controlled by sequential epithelial-mesenchymal interactions. However, little is known about the differentiation and maturation mechanisms. OD314 was firstly identifled from odontoblasts by subtraction between odontoblast/pulp cells and osteoblast/dental papilla cells, even though OD314 protein was also expressed in ameloblast during tooth formation. In this study, to better understand the biologcal function of OD314 during amelogenesis, we examined expression of the OD314 mRNA and protein in various stages of ameloblast differentiation using in-situ hybridization and immunohistochemistry. The results were as follows : 1. The ameloblast showed 4 main morphological and functional stages referred to as the presecretory, secretory, smooth-ended, and ruffle-ended. 2. ○D314 mRNA was expressed in secretory ameloblast and increased according to the maturation of the cells. 3. OD314 protein was not expressed in presecretory ameloblast but expressed in secretory ameloblast and maturative ameloblast. OD314 protein was distributed in entire cytoplasm of secretory ameloblast. However, OD314 was localized at the proxiamal and distal portion of the cytoplasm of smooth- ended and ruffle-ended ameloblast. These results suggest that ○D314 may play important roles in the ameloblast differentiation and maturation.

Quantitative Feasibility Evaluation of ¹¹C-Methionine Positron Emission Tomography Images in Gamma Knife Radiosurgery : Phantom-Based Study and Clinical Application

Lim, Sa-Hoe,Jung, Tae-Young,Jung, Shin,Kim, In-Young,Moon, Kyung-Sub,Kwon, Seong-Young,Jang, Woo-Youl The Korean Neurosurgical Society 2019 Journal of Korean neurosurgical society Vol.62 No.4

Objective : The functional information of $^{11}C$-methionine positron emission tomography (MET-PET) images can be applied for Gamma knife radiosurgery (GKR) and its image quality may affect defining the tumor. This study conducted the phantom-based evaluation for geometric accuracy and functional characteristic of diagnostic MET-PET image co-registered with stereotactic image in Leksell $GammaPlan^{(R)}$ (LGP) and also investigated clinical application of these images in metastatic brain tumors. Methods : Two types of cylindrical acrylic phantoms fabricated in-house were used for this study : the phantom with an array-shaped axial rod insert and the phantom with different sized tube indicators. The phantoms were mounted on the stereotactic frame and scanned using computed tomography (CT), magnetic resonance imaging (MRI), and PET system. Three-dimensional coordinate values on co-registered MET-PET images were compared with those on stereotactic CT image in LGP. MET uptake values of different sized indicators inside phantom were evaluated. We also evaluated the CT and MRI co-registered stereotactic MET-PET images with MR-enhancing volume and PET-metabolic tumor volume (MTV) in 14 metastatic brain tumors. Results : Imaging distortion of MET-PET was maintained stable at less than approximately 3% on mean value. There was no statistical difference in the geometric accuracy according to co-registered reference stereotactic images. In functional characteristic study for MET-PET image, the indicator on the lateral side of the phantom exhibited higher uptake than that on the medial side. This effect decreased as the size of the object increased. In 14 metastatic tumors, the median matching percentage between MR-enhancing volume and PET-MTV was 36.8% on PET/MR fusion images and 39.9% on PET/CT fusion images. Conclusion : The geometric accuracy of the diagnostic MET-PET co-registered with stereotactic MR in LGP is acceptable on phantom-based study. However, the MET-PET images could the limitations in providing exact stereotactic information in clinical study.

Decreased Glomerular Filtration Rate is an Independent Predictor of In-Hospital Mortality in Patients With ST-Segment Elevation Myocardial Infarction Undergoing Primary Percutaneous Coronary Intervention

Kim, Joon Young,Jeong, Myung Ho,Ahn, Yong Keun,Moon, Jae Hyun,Chae, Shung Chull,Hur, Seung Ho,Hong, Taek Jong,Kim, Young Jo,Seong, In Whan,Chae, In Ho,Cho, Myeong Chan,Kim, Chong Jin,Jang, Yang Soo,Yo The Korean Society of Cardiology 2011 Korean Circulation Journal Vol.41 No.4

<P><B>Background and Objectives</B></P><P>Patients with renal dysfunction (RD) experience worse prognosis after myocardial infarction (MI). The aim of the present study was to investigate the impact of admission estimated glomerular filtration rate (eGFR) on clinical outcomes of patients undergoing primary percutaneous coronary intervention (PCI) for ST-segment elevation MI (STEMI).</P><P><B>Subjects and Methods</B></P><P>We retrospectively evaluated 4,542 eligible patients from the Korea Acute Myocardial Infarction Registry (KAMIR). Patients were divided into three groups according to eGFR (mL/min/1.73 m<SUP>2</SUP>): normal renal function (RF) group (eGFR ≥60, n=3,515), moderate RD group (eGFR between 30 to 59, n=894) and severe RD group (eGFR <30, n=133). Baseline characteristics, angiographic and procedural results, and in-hospital outcomes between the three groups were compared.</P><P><B>Results</B></P><P>Age, gender, Killip class ≥3, hypertension, diabetes, congestive heart failure, peak creatine kinase-MB, high sensitivity C-reactive protein, B-type natriuretic peptide, left ventricle ejection fraction, multivessel disease, infarct-related artery and rate of successful PCI were significantly different between the 3 groups (p<0.05). With decline in RF, in-hospital complications developed with an increasing frequency (14.1% vs. 31.8% vs. 45.5%, p<0.0001). In-hospital mortality rate was significantly higher in the moderate and severe RD groups as compared to the normal RF group (2.3% vs. 13.9% vs. 25.6%, p<0.0001). Using multivariate logistic regression analysis, adjusted odds ratio for in-hospital mortality was 2.67 {95% confidence interval (CI) 1.44-4.93, p=0.002} in the moderate RD group, and 4.09 (95% CI 1.48-11.28, p=0.006) in the severe RD group as compared to the normal RF group.</P><P><B>Conclusion</B></P><P>Decreased admission eGFR was associated with worse clinical courses and it was an independent predictor of in-hospital mortality in STEMI patients undergoing primary PCI.</P>

운행중인 전후 동력형 디젤 동차의 배출가스 특성

강성인,송문석,김문헌 崇實大學校 生産技術硏究所 1998 論文集 Vol.28 No.-

In this paper, exhaust gas emissions fo moving push-pull Semaul diesel hydraulic car are measured as a function of ambient conditions, rail conditions, the chief stations and in the case of arrival and departure ar stations. In result of measurement of exhaust gas emissions, CO adn NO?? emissions are inreased linearly according to increasing of engine speed until 1,500rpm. On the same ambient temperature, CO emission is decreased and NO?? emission is increaed according to increasing of ambient humidity. In the chief station, CO and NO?? are exceeded a limitation of exhaust gas emissions as 2 times and 1.6 times respectively at Chupungtryeong. When the diesel car start at the station, CO and NO?? are approximated and exceeded the limitation.

Optimum Global Failure Prediction Model of Inconel 600 Thin Plate with Two Parallel Through-Wall Cracks

Moon Seong In,Kim Young Jin,Lee Jin Ho,Song Myung Ho,Choi Young Hwan Korean Nuclear Society 2004 Nuclear Engineering and Technology Vol.36 No.4

The $40\%$ of wall criterion, which is generally used for the plugging of steam generator tubes, is applied only to a single crack. In a previous study, a total number of 9 failure models were proposed to estimate the local failure of the ligament between cracks, and the optimum coalescence model of multiple collinear cracks was determined among these models. It is, however known that parallel axial cracks are more frequently detected than collinear axial cracks during an in-service inspection. The objective of this study is to determine the plastic collapse model that can be applied to steam generator tubes containing two parallel axial through-wall cracks. Three previously proposed local failure models were selected as the candidates. Subsequently, the interaction effects between two adjacent cracks were evaluated to screen them. Plastic collapse tests for the plate with two parallel through-wall cracks and finite element analyses were performed to determine the optimum plastic collapse model. By comparing the test results with the prediction results obtained from the candidate models, a COD base model was selected as an optimum model.