Peroxiredoxin II promotes hepatic tumorigenesis through cooperation with Ras/Forkhead box M1 signaling pathway

Park, Y-H,Kim, S-U,Kwon, T-H,Kim, J-M,Song, I-S,Shin, H-J,Lee, B-K,Bang, D-H,Lee, S-J,Lee, D-S,Chang, K-T,Kim, B-Y,Yu, D-Y Macmillan Publishers Limited 2016 Oncogene Vol.35 No.27

<P>The current study was carried out to define the involvement of Peroxiredoxin (Prx) II in progression of hepatocellular carcinoma (HCC) and the underlying molecular mechanism(s). Expression and function of Prx II in HCC was determined using H-ras(G12V)-transformed HCC cells (H-ras(G12V)-HCC cells) and the tumor livers from H-ras(G12V)-transgenic (Tg) mice and HCC patients. Prx II was upregulated in H-ras(G12V)-HCC cells and H-ras(G12V)-Tg mouse tumor livers, the expression pattern of which highly similar to that of forkhead Box M1 (FoxM1). Moreover, either knockdown of FoxM1 or site-directed mutagenesis of FoxM1-binding site of Prx II promoter significantly reduced Prx II levels in H-ras(G12V)-HCC cells, indicating FoxM1 as a direct transcription factor of Prx II in HCC. Interestingly, the null mutation of Prx II markedly decreased the number and size of tumors in H-ras(G12V)-Tg livers. Consistent with this, knockdown of Prx II in H-ras(G12V)-HCC cells reduced the expression of cyclin D1, cell proliferation, anchorage-independent growth and tumor formation in athymic nude mice, whereas overexpression of Prx II increased or aggravated the tumor phenotypes. Importantly, the expression of Prx II was correlated with that of FoxM1 in HCC patients. The activation of extracellular signal-related kinase (ERK) pathway and the expression of FoxM1 and cyclin D1 were highly dependent on Prx II in H-ras(G12V)-HCC cells and H-ras(G12V)-Tg livers. Prx II is FoxM1-dependently- expressed antioxidant in HCC and function as an enhancer of Ras(G12V) oncogenic potential in hepatic tumorigenesis through activation of ERK/FoxM1/cyclin D1 cascade.</P>

Calculations of AC magnetic losses from the experimental field profiles in various types of coated conductors under applied fields

Yoo, J,Lee, S,Jung, Y,Lee, J,Youm, D,Ha, H,Kim, H,Ko, R-K,Oh, S Institute of Physics 2008 Journal of physics. Conference series Vol.97 No.1

<P>We measured the field profiles, <I>H</I>(<I>x,H</I><SUB>a</SUB>) s, near the surface of coated conductors (CCs) by using the scanning Hall probe method. The samples were SmBCO-CC tape fabricated by co-evaporation method and YBCO-CC tape fabricated by PLD method. The applied fields, <I>H</I><SUB>a</SUB>s, were decreased from <I>H</I><SUB>peak</SUB>to -<I>H</I><SUB>peak</SUB> stepwise. From the values of <I>H</I>(<I>x,H</I><SUB>a</SUB>), we calculated the current profiles, <I>J</I>(<I>x,H</I><SUB>a</SUB>) s, by the inversion method. From the values of <I>J</I>(<I>x,H</I><SUB>a</SUB>) and the corresponding flux densities, we calculated the hysteretic energy losses per cycle, <I>Q</I><SUB>M</SUB>s, for various <I>H</I><SUB>peak</SUB>s. From the values of <I>Q</I><SUB>M</SUB>, we calculated the characteristic functions, <I>g</I>s, by using the relation, <I>g</I>= π<I>Q</I><SUB>M</SUB>/μ<SUB>0</SUB><I>I</I><SUP>2</SUP><SUB>c</SUB>. Here, <I>I</I><SUB>c</SUB> is the critical current. For the range of <I>H</I><SUB>peak</SUB>/<I>H</I><SUB>c</SUB>≤ 3, the <I>g</I>-values of SmBCO CC tape were larger than those of YBCO CC tape. However, for the range of <I>H</I><SUB>peak</SUB>/<I>H</I><SUB>c</SUB> ≥ 3, the <I>g</I>-values of SmBCO CC tape were smaller than those of YBCO CC tape. When <I>H</I><SUB>peak</SUB>/<I>H</I><SUB>c</SUB> = 3, both sample show almost same value of <I>g.</I>However we found qualitatively different <I>J–B</I> hysteretic curves for both samples. We also compared our <I>g</I>-values with other <I>g</I>-values, which were directly measured by energy loss experiments. Our <I>g</I>-values of YBCO CC tapes were basically similar to the Brandt's theoretical values of <I>g</I> in the most range of <I>I</I><SUB>peak</SUB> in our measurements.</P>

자외선의 조사간격이 브로일러 병아리의 볏 피부중 비타민 D₃함량에 미치는 영향

조인호,장윤환,이은택,여영수,배은경,김중달 한국축산학회 1994 한국축산학회지 Vol.36 No.1

This study was conducted to determine the content, of previtamin D₃(PreD₃), lumisterol₃(L₃), vitamin D₃(VD₃) and provitamin D₃(ProD₃) in comb skski of broiler chicks exposed to medium ware ultraviolet(UVB) lights in different interval. The broiler Hubbard line day old chicks(199 = 10 control + 3 irradiation interval × 9 elapsed time × 7 replica) were fed vitamin D deficient diet for 3 weeks in a windowless subdued light room and exposed to 297 ㎚ UVB light by 0.068 mJ/㎝-(10 min) three times in 0, 12 or 24 h interval. The comb skin were taken at 0, 6, 12, 18, 24, 48, 96, 144 or 240 h after last irradiation, and epidermis and dermis were separated. The lipid in sample was extracted by 9% ethyl acetate/hexane and purified by Sep-Pak silica catridge. The stright phase HPI-C was applied to analyze the concentration of Prop; and its photoproducts. When chicks were exposed once to UVB light for 30 min without interval, the mole % of ProD₃ in comb epidermis were 100% at control and 52.65% at 0 h after irradiation, thereafter it increased gradually to 88.17% at 240 h. PreD₃ and L₃ presented the maximum mole % at 0 h. VD₃ showed the peak value at 12 h. then decreased slowly. As UVB light was utilized to irradiate the chicks for 10 thin three times in 12 h interval, the ProD₃ mole portion in epidermis at 0 h was 76.4%, the lowest value among tested. PreD₃ and 1-3 preserved the highest level at 24 and 0 h, respectively, thereafter decreased gradully. VD₃ showed a peak at 6 h after exposure. When 24 h interval system was treated, the lowest value of ProD₃ 83.52% was appeared at 0 h. PreD₃ and L3 showed the highest level at 6 and 0 h, respectively. Mole ale of VD₃ had a peak value at 6 h and thin decreased. The mole % of ProD₃ and its photoproduets in comb dermis presented similar trends of time course variation as in those in epidermis. In respecting the method of UVB irradiation the PreD₃, L, and VDT were produced more quickly and largely in no intend system as compared to the time and amount produced in 12 or 24 h interval system.

Relationships of Plasma Insulin-like Growth Factor (IGF)-Ⅰ and IGF-ⅡConcentrations to Litter Size and Lactation Performance in Landrace and Yorkshire Pigs

Lee, C. Y.,Baik, K. H.,Lee, D. H.,Park, H. C. 한국동물자원과학회 2003 한국축산학회지 Vol.45 No.1

본 연구는 혈장의 insulin-like growth factor(IGF)-Ⅰ과 IGF-Ⅱ 농도와 산자수 및 비유성적과의 관계를 구명하고자 착수되었다. 분만주가 비슷한 미경산 및 경산 임신돈 중에서 선발한 총 60두의 순종 Landrace와 Yorkshire 공시돈을 저산자수 (low; <μ - 0.5 SD)와 고산자수 (high; >μ + 0.5 SD)-lines로 구분하여 2 (품종) × 2(line) 요인분석 실험설계 하에 본 실험을 진행 하였다. 공시돈은 분만시 모돈당 포유자돈수를 9두로 고정시키고, 3주령 이유시 비유량의 척도로서 총 이유자돈 체중을 측정하였다. 혈액시료는 임신 90일과 분만 후 15일에 경정맥으로부터 채취하였다. 본 실험기간 중 산자수 및 본 실험기간까지의 평균 산자수는 high-line이 low-line보다 각각 3.7두와 2.4두 많았고 (P<0.01), 두 품종간 산자수 차이는 없었다. 임신 90일 혈장의 IGF-Ⅱ 농도는 low-line보다 high-line에서 높았다. 산자수는 임신 90일 IGF-Ⅰ 농도와 Landrace에서는 부의 상관관계를 나타냈고 (r=-0.46; P<0.05), Yorkshire에서는 부의 상관관계 경향을 나타내어 (r=-0.31; P=0.09) 전체 공시돈에서는 이들 두 변수간 유의적인 부의 상관관계를 보였다 (r=-0.35; P< 0.01). 이유시 모돈당 총 이유자돈 체중은 두 품종간 혹은 두 lines간 차이가 없었다. 이유자돈 체중과 IGF 농도와의 관계는 품종 × 생리적인 생태 조합들간 일정한 경향을 나타내지 않았다. 이상의 결과는 임신 90일 IGF 농도가 임박한 분만시 산자수의 지표가 될 수 있는 가능성을 시사한다. The present study was undertaken to find relationships of plasma insulin-like growth factor (IGF)-Ⅰand IGF-Ⅱ concentrations to litter size and lactation performance. Sixty pure-bred Landrace and Yorkshire pigs having similar farrowing weeks which had been selected from a large number of pregnant gilts and sows were divided into low- (<?? - 0.5SD) and high-litter size (>?? + 0.5 SD) lines under a 2 (breed) × 2 (line) factorial arrange of treatments. After adjusting the litter size to nine piglets per sow at farrowing, total litter weight was measured at three weeks postpartum at weaning as an index of milk yield. Blood samples were obtained from the jugular vein at day (d)-90 pregnancy (Px) and at d-15 postpartum. The litter size or the number of piglets born during the present experiment and the average litter size during the entire parities up to the present one were greater in the high-line than in the low-line by 3.7 and 2.4 piglets. respectively (P<0.01); effect of the breed on litter size was not significant. Plasma IGF-Ⅱ concentration at d-90 Px was greater in the high-line than in the low-line. Litter size and d-90 Px IGF-Ⅰconcentration were negatively correlated in Landrace (r=-0.46; P<0.05) and tended to be negatively correlated in Yokshire (r=-0.31; P=0.09), which resulted in a significant negative correlation between these two variables in total animals (r=-0.35; P<0.01). Litter weight at weaning was not different between the two breeds or lines. Relationships between the litter weight and IGF concentration were not consistent across the breed × physiological stage combinations. Results suggest that d-90 Px IGF concentrations may be indicative of the litter size at impending farrowing.

Heat transfer with fully developed slot jets impinging on confined concave and convex surfaces

Lee, D.H.,Kim, S.J.,Kim, Y.H.,Park, H.J. Pergamon Press ; Elsevier Science Ltd 2015 INTERNATIONAL JOURNAL OF HEAT AND MASS TRANSFER - Vol.88 No.-

This research investigates the laminar heat transfer characteristics of a milli-scale confined slot jet impinging upon concave and convex surfaces at a uniform heat flux. The flow at the nozzle exit has a fully-developed velocity profile. The effects of Reynolds number (Re), nozzle-to-surface distance (H/B) and the geometrical shape of target surface on local heat transfer are investigated. The heat transfer measurements are conducted at Reynolds numbers ranging from of 200 to 600 and H/B from 2 to 12. The results show that the local Nusselt numbers for both surfaces increase with increasing Reynolds number. The axial distributions of local Nusselt numbers exhibit the peak at the stagnation point and monotonically decrease in the wall jet region, showing a bell-shaped for all Re's and H/B's tested. The results also show that the peak stagnation point Nusselt numbers occur at around H/B=5-7 for the convex surface. On the contrary, the stagnation point Nusselt numbers for the concave surface tend to gradually decrease as the nozzle-to-surface distance increases. The stagnation point Nusselt numbers for the concave surface are higher than those for the convex surface at all Re's and H/B's tested.

Ahnak functions as a tumor suppressor via modulation of TGFβ/Smad signaling pathway

Lee, I H,Sohn, M,Lim, H J,Yoon, S,Oh, H,Shin, S,Shin, J H,Oh, S-H,Kim, J,Lee, D K,Noh, D Y,Bae, D S,Seong, J K,Bae, Y S Macmillan Publishers Limited 2014 Oncogene Vol.33 No.38

We provide detailed mechanisms of Ahnak-mediated potentiation of transforming growth factor β (TGFβ) signaling, which leads to a negative regulation of cell growth. We show that Smad3 interacts with Ahnak through MH2 domain and that Ahnak stimulates Smad3 localization into nucleus leading to potentiating TGFβ-induced transcriptional activity of R-Smad. Moreover, overexpression of Ahnak resulted in growth retardation and cell cycle arrest through downregulation of c-Myc and cyclin D1/D2. We describe results from analyses of Ahnak<SUP>−/−</SUP> mouse model expressing middle T antigen in a mammary gland-specific manner (MMTV<SUP>Tg/+</SUP>Ahnak<SUP>−/−</SUP>), which showed significantly progressed hyperplasia of mammary glands compared with MMTV<SUP>Tg/+</SUP>Ahnak<SUP>+/+</SUP>. Finally, we screened multiple human breast cancer tissues and showed that the expression of Ahnak in cancer tissues is lower than that in control tissues by 50%. Taken together, these data indicate that Ahnak mediates a negative regulation of cell growth and acts as novel tumor suppressor through potentiation of TGFβ signaling.

Inhibitory effects of sulfur compounds on methane oxidation by a methane-oxidizing consortium

Lee, E.H.,Moon, K.E.,Kim, T.G.,Lee, S.D.,Cho, K.S. Society for Bioscience and Bioengineering, Japan ; 2015 Journal of bioscience and bioengineering Vol.120 No.6

Kinetic and enzymatic inhibition experiments were performed to investigate the effects of methanethiol (MT) and hydrogen sulfide (H<SUB>2</SUB>S) on methane oxidation by a methane-oxidizing consortium. In the coexistence of MT and H<SUB>2</SUB>S, the oxidation of methane was delayed until MT and H<SUB>2</SUB>S were completely degraded. MT and H<SUB>2</SUB>S could be degraded, both with and without methane. The kinetic analysis revealed that the methane-oxidizing consortium showed a maximum methane oxidation rate (V<SUB>max</SUB>) of 3.7 mmol g-dry cell weight (DCW)<SUP>-1</SUP> h<SUP>-1</SUP> and a saturation constant (K<SUB>m</SUB>) of 184.1 μM. MT and H<SUB>2</SUB>S show competitive inhibition on methane oxidation, with inhibition values (K<SUB>i</SUB>) of 1504.8 and 359.8 μM, respectively. MT was primary removed by particulate methane monooxygenases (pMMO) of the consortium, while H<SUB>2</SUB>S was degraded by the other microorganisms or enzymes in the consortium. DNA and mRNA transcript levels of the pmoA gene expressions were decreased to ~10<SUP>6</SUP> and 10<SUP>3</SUP>pmoA gene copy number g-DCW<SUP>-1</SUP> after MT and H<SUB>2</SUB>S degradation, respectively; however, both the amount of the DNA and mRNA transcript recovered their initial levels of ~10<SUP>7</SUP> and 10<SUP>5</SUP>pmoA gene copy number g-DCW<SUP>-1</SUP> after methane oxidation, respectively. The gene expression results indicate that the pmoA gene could be rapidly reproducible after methane oxidation. This study provides comprehensive information of kinetic interactions between methane and sulfur compounds.

Prognostic factors of Acute Myelocytic leukemia: An Analysis of 132 Patients in a Single Institution

Lee, K.-H Korean Academy of Medical Science 1996 Journal of Korean medical science Vol.11 No.3

CAN통신을 이용한 H-브릿지 멀티레벨 인버터의 PWM 동기화 및 위상전이 방법

박영민(Y.M.Park),유한승(H.S.Yoo),장성영(S.Y.Jang),이현원(H.W.Lee),이세현(S.H.Lee),서광덕(K.D.Seo) 전력전자학회 2004 전력전자학술대회 논문집 Vol.- No.-

H-브릿지 멀티레벨 인버터는 여러 개의 단상 Power Cell을 직렬로 연결함으로써 저전압 전력용 반도체를 사용하여 고전압을 얻을 수 있고, 정현파에 가까운 출력전압 파형을 얻을 수 있는 멀티레벨 인버터 토폴로지이다. 본 토폴로지는 출력전압 레벨에 비례하여 Power Cell의 수가 증가하므로, 주제어기의 연산능력에 대한 부담증가와 신호선의 많아지는 단점이 있다. 따라서 Power Cell제어를 직접적인 PWM 신호가 아닌 통신을 사용함으로써 이러한 단점을 극복할수 있으며, 신뢰성 측면이나 보수/유지 측면에서도 유리하다. 본 논문은 산업현장에서 신뢰성을 인정받아 많이 사용되고 있는 직렬통신 방식의 일종인 CAN통신 인터럽터를 이용한 H-브릿지 멀티레벨 인버터 Power Cell의 PWM 동기화 및 위상전이 방법에 관한 것이다. 제안된 방법의 주요 장점은 주제어기와 셀 제어기 사이에 직렬통신(CAN)을 사용함으로써 주제어기와 셀 제어기의 신호선의 단순화, 주제어기의 부담 감소, Power Cell의 모듈화, 셀 단위의 보호동작 용이, 확장성 향상 그리고 제어 신호 및 Power Cell의 신뢰성을 향상에 있다. 13레벨로 구성된 H-브릿지 멀티레벨 인버터 시험을 통해 제안된 방법의 타당성과 신뢰성을 입증하였다.

두개골의 단순전후 방사선 사진을 이용한 전두동의 분류 및 그 분포에 관한 연구

이혜경,권귀향,김기정,강신몽,문국진 순천향대학교 2002 Journal of Soonchunhyang Medical Science Vol.8 No.4