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Hyun Jung Lee,
Kyungmin Lee,
Dong Gwang Lee,
Kwang-Hee Bae,
Jang-Seong Kim,
Zhe Long Liang,
Song Mei Huang,
Yoon Suk Oh,
Ha Yon Kim,
Deog Yeon Jo,
Jeong-Ki Min,
Jin-Man Kim,
Hyo Jin Lee
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ABSTRACT: Although recent studies have suggested that chemokine (C-X-C motif) ligand 12 (CXCL12) is important in the progression of various malignancies, its role in gallbladder carcinoma (GBC) remains unknown. We investigated CXCL12 expression in GBC and its biologic and prognostic role in GBC tumorigenesis.
We examined CXCL12 expression in tumor specimens from 72 patients with GBC by immunohistochemistry and analyzed the correlation between CXCL12 expression and clinicopathologic factors or survival. The functional significance of CXCL12 expression was investigated by CXCL12 treatment and suppression of CXCR4, a major receptor of CXCL12, as well as by CXCL12 overexpression in in vitro and in vivo studies.
CXCL12 was differentially expressed in GBC tissues. CXCL12 expression was significantly associated with a high histologic grade (P = 0.042) and nodal metastasis (P = 0.015). Multivariate analyses showed that CXCL12 expression (HR, 8.675; P = 0.014) was an independent risk factor for patient survival. CXCL12 significantly increased anchorage-dependent and -independent growth, migration, invasion, adhesiveness, and survival of GBC cells in vitro, and these effects were dependent on CXCR4. Consistent with these results, overexpression of CXCL12 significantly promoted GBC tumorigenicity in a xenograft model.
Our results indicate that GBC cells express both CXCL12 and its receptor CXCR4, and CXCL12 may have a role in GBC progression through an autocrine mechanism. In addition, CXCL12 is a novel independent poor prognostic factor in patients with GBCs. Thus, targeting CXCL12 and CXCR4 may provide a novel therapeutic strategy for GBC treatment.
Clinical Cancer Research 05/2012; 18(12):3270-80. · 7.74 Impact Factor
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ABSTRACT: Interleukin-32 (IL-32) is a proinflammatory cytokine that acts as a significant pathogenetic factor in various diseases and malignancies. However, the clinical effect of IL-32 expression in renal cell carcinoma (RCC) has not previously been investigated. The aim of the present study was to examine the significance of IL-32 overexpression in localized clear cell RCC (CCRCC). We examined 112 patients with localized CCRCC who underwent nephrectomy. The clinicopathological data were obtained by retrospective review and the expression levels of IL-32 were studied by immunohistochemistry. Tumors were classified according to staining intensity (0, no staining intensity; 1, weak; 2, intermediate; 3, strong). The cases with staining intensities from 0 to 2 comprised the IL-32 low-expression group (LEG), whereas those with a staining intensity of 3 comprised the IL-32 high-expression group (HEG). Correlations between IL-32 expression and clinicopathological parameters were determined. Staining intensities were determined for all cases as follows: 26 cases (23.2%) (score 0), 43 cases (38.4%) (score 1), 31 cases (27.7%) (score 2) and 12 cases (10.7%) (score 3). IL-32 HEG exhibited a higher recurrence rate compared to the IL-32 LEG (50 vs. 13%, P=0.001). For survival rates, the 5-year recurrence-free survival (RFS), disease-specific survival (DSS) and overall survival (OS) rates were lower in the IL-32 HEG group compared with the IL-32 LEG group (RFS, P=0.001; DSS, P<0.001; OS, P=0.026, respectively). Univariate analyses revealed that Fuhrman nuclear grade and a high IL-32 expression were significant prognostic factors for predicting RFS, DSS and OS in CCRCC, whereas multivariate analyses indicated that Fuhrman nuclear grade and high IL-32 expression were still independent risk factors. In conclusion, IL-32 overexpression was associated with high recurrence rates and low RFS, DSS and OS, indicating that it may be a novel prognostic factor for predicting outcomes in patients with CCRCC.
Oncology letters 02/2012; 3(2):490-496. · 0.11 Impact Factor
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Soo Hwan Park,
W.S. Han,
K.M. Moon,
W.W. Park,
J.S. Kim,
H. Yonekawa,
Yong Chu, Hyun Jung Lee,
K.W. Cho,
K.R. Park,
W.C. Kim,
Yaung-Soo Kim,
Y.K. Oh,
J.S. Bak
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ABSTRACT: KSTAR (Korea Superconducting Tokamak Advanced Research) superconducting magnet consists of a CICC (Cable-In-Conduit Conductor) and is cooled down less than 5 K using supercritical helium. The length of CICC is 610 m for TF coil and maximum about 2,500 m for PF coil respectively, especially the cooling channel is about maximum 300 m in PF coil because of continuous winding scheme. There are many cooling channels in KSTAR coils especially 84 channels in TF magnet system and 100 channels in PF magnet system. Flow imbalance affects cool down of magnet and leads to a difficulty of flow control. The pressure drop between CICC terminals has a close relationship with CICC hydraulic characteristic, helium refrigerator's performance and efficiency. The friction factor which is a representative parameter can be obtained under cryogenic operation condition. We attempt to find out the friction factor of KSTAR CS and PF CICC according to the test result of KSTAR CSMC (Central Solenoid Model Coil) 2nd campaign and compare the results with previous tests. The hydraulic characteristics of KSTAR superconducting magnet system like mass flow distribution, friction factor in conductor, pressure drop and etc during CSMC test and initial commissioning of KSTAR are presented. We can confirm the KSTAR CICC's unique hydraulic behavior in states of cool down and current charging period. Also, we expect that measured data will help to operate KSTAR and be a reference for thermo-hydraulic simulation.
IEEE Transactions on Appiled Superconductivity 07/2009; · 1.04 Impact Factor
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H. Yonekawa,
Y.O. Kim, Hyun Jung Lee,
S.W. Yoon,
S.H. Hahn,
K.S. Lee,
D.K. Lee,
Soo Hwan Park,
Yong Chu,
E.N. Bang,
K.R. Park,
Y.K. Oh,
J.S. Bak,
J.A. Leuer
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ABSTRACT: An in situ measurement of the magnetic field generated by the assembled superconducting magnet coils was held by using precision Hall sensors during the commissioning of the Korea Superconducting Tokamak Advanced Research (KSTAR) device. This was done in order to investigate the magnetic influence of Incoloy 908, which is the jacket material for the cable-in-conduit conductors (CICCs) of the Nb<sub>3</sub>Sn coils. After the PF coils were discharged from 1 kA the vertical remanent field at the plasma center was more than 10 G, while the TF coils were not energized. The vertical magnetic field generated by the PF coils had a discrepancy of up to 50 G between measurement and the calculation assuming no magnetic influence of Incoloy 908. Thus, non-negligible ferromagnetism was identified and attributed to Incoloy 908. In contrast, most of the hysteresis observed in the magnetic measurements was eliminated when the Incoloy 908 of the TF windings was saturated by the TF coil charging.
IEEE Transactions on Appiled Superconductivity 07/2009; · 1.04 Impact Factor
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Yong Chu,
H. Yonekawa,
Y.O. Kim,
K.R. Park, Hyun Jung Lee,
M.K. Park,
Y.M. Park,
S.J. Lee,
T.H. Ha,
Y.K. Oh,
J.S. Bak
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ABSTRACT: To protect the KSTAR (Korea Superconducting Tokamak Advanced Research) superconducting coils against a quench, the quench detection system based on voltage measurement was fabricated. It used a detect/dump scheme which detects the presence of non-recovering normal zones and activates a dump circuit that transfers most of the stored energy into a dump resistor. Even though it is desirable to discharge the coil energy as fast as possible after quench detection, a time delay between the quench detection and the complete dump circuit actuation will be necessary in order that the quench voltage is to be distinguished from various noises. The quench threshold voltage and the delay time should be set before operation for quench voltage detection so that the maximum hot-spot temperature could be limited to 150 K. This paper describes the hardware techniques to prevent the malfunction of the quench detection due to voltage noises arising from the KSTAR operating scenarios. During the first operation of the KSTAR machine, the inductive voltages and other voltage noises were measured and effectively compensated below voltage thresholds. A quench did not occur and the quench detection system was well operated without any false activation.
IEEE Transactions on Appiled Superconductivity 07/2009; · 1.04 Impact Factor
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K.R. Park,
Yong Chu,
H. Yonekawa,
E.N. Baang,
Y.O. Kim, Hyun Jung Lee,
Y.M. Park,
Y.J. Lee,
H.S. Chang,
D.K. Lee,
J.H. Choi,
S.H. Park,
S.H. Hahn,
K.H. Kim,
I.S. Hwang,
M.K. Park,
K.W. Cho,
Y.S. Kim,
Y.K. Oh,
J.S. Bak
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ABSTRACT: To achieve the first plasma of the Korea superconducting tokamak advanced research (KSTAR), the KSTAR superconducting coils were tested in advance. As they should operate in excessively low temperature of 4.5 K and high magnetic field environment of 7.5 T, it is crucial to monitor the cryogenic and the structural behaviors of KSTAR device during the commissioning period including a cool-down. The temperatures of the KSTAR toroidal field (TF) coil and the poloidal field (PF) coils were measured during the entire operating period. The mechanical stresses on the TF and PF structures were continuously monitored to check if they go beyond the limiting value calculated through the simulation. The alignment of the KSTAR device was checked by using displacement sensors. The TF coils were successfully supplied with 15 kA DC current for 8 hours, and the maximum 5 kA/s current variation of the PF coils were tested. For the main experiment, the interlock test of the quench detection system for the KSTAR coils was carried out at reduced currents of 1 kA. From these results the quench protection circuit, and the current-flow of the KSTAR superconducting coils proved to be well performed for the first plasma operation.
IEEE Transactions on Appiled Superconductivity 07/2009; · 1.04 Impact Factor
