Ji Hoon Jung

Publications of Ji Hoon Jung

• Activation of reactive oxygen species/AMP activated protein kinase signaling mediates fisetin-induced apoptosis in multiple myeloma U266 cells.

  Authors: Ki Young Jang, Soo-Jin Jeong, Sun-Hee Kim, Ji Hoon Jung, Ji-Hyun Kim, Wonil Koh, Chang-Yan Chen, Sung-Hoon Kim

  Cancer letters. 01/2012;

  We investigated the molecular mechanisms responsible for fisetin-induced apoptosis in U266 cells. Fisetin elicited the cytotoxicity in U266 cells, manifested as an increased fraction of the cellsWe investigated the molecular mechanisms responsible for fisetin-induced apoptosis in U266 cells. Fisetin elicited the cytotoxicity in U266 cells, manifested as an increased fraction of the cells with sub-G1 content or stained positively with TUNEL labeling. Fisetin enhanced caspase-3 activation, downregulation of Bcl-2 and Mcl-1(L), and upregulation of Bax, Bim and Bad. Fisetin activated AMPK as well as its substrate acetyl-CoA carboxylase (ACC), along with a decreased phosphorylation of AKT and mTOR. Fisetin also stimulated generation of ROS in U266 cells. Conversely, compound C or N-acetyl-l-cystein blocked fisetin-induced apoptosis. Our data suggest that fisetin-induced apoptosis in U266 cells is through ROS and AMPK pathways.

• Inhibition of STAT3 signaling and induction of SHP1 mediate antiangiogenic and antitumor activities of ergosterol peroxide in U266 multiple myeloma cells.

  Authors: Yun-Hee Rhee, Soo-Jin Jeong, Hyo-Jeong Lee, Hyo-Jung Lee, Wonil Koh, Ji Hoon Jung, Sun-Hee Kim, Kim Sung-Hoon

  BMC cancer. 01/2012; 12:28.

  ABSTRACT: Ergosterol peroxide (EP) derived from edible mushroom has been shown to exert anti-tumor activity in several cancer cells. In the present study, anti-angiogenic activity of EP wasABSTRACT: Ergosterol peroxide (EP) derived from edible mushroom has been shown to exert anti-tumor activity in several cancer cells. In the present study, anti-angiogenic activity of EP was investigated with the underlying molecular mechanisms in human multiple myeloma U266 cells. Despite weak cytotoxicity against U266 cells, EP suppressed phosphorylation, DNA binding activity and nuclear translocalization of signal transducer and activator of transcription 3 (STAT3) in U266 cells at nontoxic concentrations. Also, EP inhibited phosphorylation of the upstream kinases Janus kinase 2 (JAK2) and Src in a time-dependent manner. Furthermore, EP increased the expression of protein tyrosine phosphatase SHP-1 at protein and mRNA levels, and conversely silencing of the SHP-1 gene clearly blocked EP-mediated STAT3 inactivation. In addition, EP significantly decreased vascular endothelial growth factor (VEGF), one of STAT3 target genes at cellular and protein levels as well as disrupted in vitro tube formation assay. Moreover, EP significantly suppressed the growth of U266 cells inoculated in female BALB/c athymic nude mice and immunohistochemistry revealed that EP effectively reduced the expression of STAT3 and CD34 in tumor sections compared to untreated control. These findings suggest that EP can exert antitumor activity in multiple myeloma U266 cells partly with antiangiogenic activity targeting JAK2/STAT3 signaling pathway as a potent cancer preventive agent for treatment of multiple myeloma cells.

• Icariside II Induces Apoptosis in U937 Acute Myeloid Leukemia Cells: Role of Inactivation of STAT3-Related Signaling.

  Authors: Sang-Hun Kang, Soo-Jin Jeong, Sun-Hee Kim, Ji-Hyun Kim, Ji Hoon Jung, Wonil Koh, Jung Hyo Kim, Dae Keun Kim, Chang-Yan Chen, Sung-Hoon Kim

  PloS one. 01/2012; 7(4):e28706.

  The aim of this study is to determine anti-cancer effect of Icariside II purified from the root of Epimedium koreanum Nakai on human acute myeloid leukemia (AML) cell line U937. Icariside II blockedThe aim of this study is to determine anti-cancer effect of Icariside II purified from the root of Epimedium koreanum Nakai on human acute myeloid leukemia (AML) cell line U937. Icariside II blocked the growth U937 cells in a dose- and time-dependent manner. In this anti-proliferation process, this herb compound rendered the cells susceptible to apoptosis, manifested by enhanced accumulation of sub-G1 cell population and increased the terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL)-positive cells. Icariside II was able to activate caspase-3 and cleaved poly (ADP-ribose) polymerase (PARP) in a time-dependent manner. Concurrently, the anti-apoptotic proteins, such as bcl-x(L) and survivin in U937 cells, were downregulated by Icariside II. In addition, Icariside II could inhibit STAT3 phosphorylation and function and subsequently suppress the activation of Janus activated kinase 2 (JAK2), the upstream activators of STAT3, in a dose- and time-dependent manner. Icariside II also enhanced the expression of protein tyrosine phosphatase (PTP) SH2 domain-containing phosphatase (SHP)-1, and the addition of sodium pervanadate (a PTP inhibitor) prevented Icariside II-induced apoptosis as well as STAT3 inactivation in STAT3 positive U937 cells. Furthermore, silencing SHP-1 using its specific siRNA significantly blocked STAT3 inactivation and apoptosis induced by Icariside II in U937 cells. Our results demonstrated that via targeting STAT3-related signaling, Icariside II sensitizes U937 cells to apoptosis and perhaps serves as a potent chemotherapeutic agent for AML.

• Special AT-rich sequence-binding protein 2 and its related genes play key roles in the differentiation of MC3T3-E1 osteoblast like cells.

  Authors: In-Suk Kim, Soo-Jin Jeong, Sun-Hee Kim, Ji Hoon Jung, Young Guk Park, Sung-Hoon Kim

  Biochemical and biophysical research communications. 12/2011; 417(2):697-703.

  Special AT-rich sequence-binding protein (SATB) plays a critical role in bone generation and osteoblast differentiation. In the present study, the differentially expressed genes by SATB2Special AT-rich sequence-binding protein (SATB) plays a critical role in bone generation and osteoblast differentiation. In the present study, the differentially expressed genes by SATB2 overexpression were analyzed in MC3T3-E1 osteoblast-like cells using Alizarin red S staining, wound healing assay and Agilent's Human Oligo Microarray. Calcium mineralization and motility were significantly enhanced in SATB2-overexpressed cells compared with untreated control. In addition, using the GeneSpringGX 7.3 program to compare the identified genes expressed in SATB2-overexpresed cells with untreated control, we found several unique genes closely associated with osteoblast differentiation, including SOX2, MBP2, WNT11 and MEN1 (up-regulated genes), and ILK, FGF23, FGFR2, and SNAI1 (down-regulated genes). Consistent with microarray data, real-time RT-PCR confirmed the significant up- and down-regulation of these genes at mRNA level in SATB2-overexpressed MC3T3-E1 cells. Overall, our findings suggest that the molecular regulation of SATB2 can be an attractive approach to develop a novel therapeutic strategy for bone-related diseases.

• Resistance of Helicobacter pylori strains to antibiotics in Korea with a focus on fluoroquinolone resistance.

  Authors: Jun-Won Chung, Gin Hyug Lee, Jin-Yong Jeong, Sun Mi Lee, Ji Hoon Jung, Kee Don Choi, Ho June Song, Hwoon-Yong Jung, Jin-Ho Kim

  Journal of gastroenterology and hepatology. 07/2011; 27(3):493-7.

  Background and Aim:  New regimens, including those with new fluoroquinolones, have been developed to overcome the antibiotic resistance of Helicobacter pylori. We aimed to assess the antibioticBackground and Aim:  New regimens, including those with new fluoroquinolones, have been developed to overcome the antibiotic resistance of Helicobacter pylori. We aimed to assess the antibiotic resistance rates, as well as the molecular mechanisms of fluoroquinolone resistance, of the clinical isolates obtained in Korea. Methods:  The minimal inhibitory concentration (MIC) values of ciprofloxacin, amoxicillin, clarithromycin, metronidazole and tetracycline were determined by the agar dilution method for 185 treatment-naïve Helicobacter pylori isolates. The resistant strains were evaluated for the presence of point mutations in the quinolone resistance-determining region (QRDR) of the gyrA and gyrB genes by direct nucleotide sequencing. Results:  Twenty-nine (29/185, 15.7%) of the strains were found to be resistant to ciprofloxacin. The resistance rates to amoxicillin, clarithromycin, metronidazole and tetracycline were 2.2% (four of 185), 10.8% (20 of 185), 30.3% (56 of 185) and 0.5% (one of 185), respectively. The most common mutations in the H. pylori gyrA gene were found at codons corresponding to Asp87 (16/29, 55.2%) and Asn91 (10/29, 34.5%). Conclusions:  Primary H. pylori resistance to ciprofloxacin occurred at a high frequency. The fluoroquinolone resistance is most likely mediated through amino acid point mutation in the gyrA gene at Asn87 and Asp91.

• Cryptotanshinone enhances TNF-α-induced apoptosis in chronic myeloid leukemia KBM-5 cells.

  Authors: Ji-Hyun Kim, Soo-Jin Jeong, Tae-Rin Kwon, Sun-Mi Yun, Ji Hoon Jung, Minseok Kim, Hyo-Jung Lee, Min-Ho Lee, Seong Gyu Ko, Chang-Yan Chen, Sung-Hoon Kim

  Apoptosis : an international journal on programmed cell death. 07/2011; 16(7):696-707.

  Cryptotanshinone is a biologically active compound from the root of Salvia miltiorrhiza. In the present study, we investigated the molecular mechanisms by which cryptotanshinone is in synergy withCryptotanshinone is a biologically active compound from the root of Salvia miltiorrhiza. In the present study, we investigated the molecular mechanisms by which cryptotanshinone is in synergy with tumor necrosis factor-alpha (TNF-α) for the induction of apoptosis in human chronic myeloid leukemia (CML) KBM-5 cells. The co-treatment of cryptotanshinone with TNF-α reduced the viability of the cells [combination index (CI) < 1]. Concomitantly, the co-treatment of cryptotanshinone and TNF-α elicited apoptosis, manifested by enhanced the number of terminal deoxynucleotide transferase-mediated dUTP-nick-end labeling (TUNEL)-positive cells, the sub-G1 cell populations, and the activation of caspase-8 and -3, in comparison with the treatment with either drug alone. The treatment with cryptotanshinone further suppressed TNF-α-mediated expression of c-FLIP(L), Bcl-x(L), but the increased level of tBid (a caspase-8 substrate). Furthermore, cryptotanshinone activated p38 but not NF-κB in TNF-α-treated KBM-5 cells. The addition of a specific p38 MAPK inhibitor SB203580 significantly attenuated cryptotanshinone/TNF-α-induced apoptosis. The combination treatment of cryptotanshinone and TNF-α also stimulated the reactive oxygen species (ROS) generation. N-acetyl-L-cysteine (NAC, a ROS scavenger) was not only able to block cryptotanshinone/TNF-α-induced ROS production but also the activation of caspase-8 and p38 MAPK. Overall, our findings suggest that cryptotanshinone can sensitize TNF-α-induced apoptosis in human myeloid leukemia KBM-5 cells, which appears through ROS-dependent activation of caspase-8 and p38.

• Janus activated kinase 2/signal transducer and activator of transcription 3 pathway mediates icariside II-induced apoptosis in U266 multiple myeloma cells.

  Authors: Sun-Hee Kim, Kwang Seok Ahn, Soo-Jin Jeong, Tae-Rin Kwon, Ji Hoon Jung, Sun-Mi Yun, Ihn Han, Seok-Geun Lee, Dae Keun Kim, Minkyung Kang, Chang-Yan Chen, Jung Weon Lee, Sung-Hoon Kim

  European journal of pharmacology. 03/2011; 654(1):10-6.

  Although the flavonoid icariside II exhibits anti-inflammatory and anti-cancer activities, its molecular targets/pathways in human multiple myeloma cells are poorly understood. To analyze the effectsAlthough the flavonoid icariside II exhibits anti-inflammatory and anti-cancer activities, its molecular targets/pathways in human multiple myeloma cells are poorly understood. To analyze the effects on signal transducer and activator of transcription 3 (STAT3) signaling and apoptosis, U266 multiple myeloma cells were treated with icariside II and performed Western blotting, electrophoretic mobility gel shift assay (EMSA), RT-PCR, proliferation assay, cell cycle analysis and terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) assay. Icariside II inhibited STAT3 activation and enhanced the expression of SHP-1 and PTEN through inhibiting Janus activated kinase 2 (JAK2) and c-Src. Icariside II down-regulated the expression of STAT3 target genes Bcl-2, Bcl-x(L), survivin, cyclin D(1), COX-2 and vascular endothelial growth factor (VEGF). Also, icariside II enhanced poly (ADP-ribose) polymerase (PARP) cleavage and caspase-3 activation. Pervanadate reversed the icariside II-mediated STAT3 inactivation and also blocked the cleavages of caspase-3 and PARP, suggesting involvement of STAT3 pathway in icariside II-induced apoptosis. Furthermore, icariside II enhanced the apoptotic effects of clinically used drugs thalidomide and bortezomib in U266 cells. Icariside II could be a potential therapeutic intervention agent alone or in combination with current drugs for multiple myeloma as a novel blocker of STAT3 signaling cascades at multiple levels, contributing to its anti-proliferative and anti-apoptosis.

• JAK2/STAT5 signaling pathway mediates Bojungbangdocktang enhanced hematopoiesis.

  Authors: Jeonghan Lim, Soo-Jin Jeong, Wonil Koh, Ihn Han, Hyo-Jung Lee, Tae-Rin Kwon, Ji Hoon Jung, Jung Hyo Kim, Hyo-Jeong Lee, Eun-Ok Lee, Sun-Hyung Kim, Min-Ho Lee, Sung-Hoon Kim

  Phytotherapy research : PTR. 03/2011; 25(3):329-37.

  Bojungbangdocktang (BJBDT) is a medicinal herbal cocktail that has been used for cancer prevention and treatment in traditional Korean medicine. In the current study, BJBDT was demonstrated toBojungbangdocktang (BJBDT) is a medicinal herbal cocktail that has been used for cancer prevention and treatment in traditional Korean medicine. In the current study, BJBDT was demonstrated to regulate hematopoiesis. BJBDT significantly increased the expression of hematopoietic cytokines interleukin (IL)-3, stem cell factor (SCF), granulocyte-macrophage-colony stimulating factor (GM-CSF), thrombopoietin (TPO) and erythropoietin (EPO) at the level of mRNA and secretion in hematopoietic stem cells (HSCs). Additionally, BJBDT enhanced the phosphorylation of Janus activated kinase 2 (JAK2) and signal transducer and activator of transcription 5 (STAT5) and STAT binding to gamma interferon activated sites (GAS) in HSCs. Furthermore, BJBDT significantly enhanced the growth rate of granulocyte erythrocyte monocyte macrophage colony-forming units (CFU-GEMM) and erythroid burst forming units (BFU-E) in vitro. Moreover, BJBDT increased the level of EPO at mRNA in kidney and plasma, and the numbers of erythroid-specific antigen Ter-119(+) erythroid cells in mice with aplastic anemia induced by 20% benzene. Consistently, histochemical staining revealed BJBDT increased the bone marrow and stromal cells as well as decreased macrophages and adipocytes in bone marrow tissues of mice with aplastic anemia. Taken together, the results suggest that BJBDT can enhance hematopoiesis via hematopoietic cytokine-mediated JAK2/STAT5 pathway as a potent hematopoietic candidate. Copyright © 2010 John Wiley & Sons, Ltd.

• Signal transducer and activator of transcription 3 pathway mediates genipin-induced apoptosis in U266 multiple myeloma cells.

  Authors: Jang Choon Lee, Kwang Seok Ahn, Soo-Jin Jeong, Ji Hoon Jung, Tae-Rin Kwon, Yun-Hee Rhee, Sun-Hee Kim, Si-Young Kim, Hwi-Joong Yoon, Shudong Zhu, Chang-Yan Chen, Sung-Hoon Kim

  Journal of cellular biochemistry. 02/2011; 112(6):1552-62.

  It has drawn a lot of attention to target signal transducer and activator of transcription 3 (STAT3) as a potential strategy for cancer therapeutics. Using several myelogenous cell lines, the effectIt has drawn a lot of attention to target signal transducer and activator of transcription 3 (STAT3) as a potential strategy for cancer therapeutics. Using several myelogenous cell lines, the effect of genipin (an active compound of Gardenia fruit) on the STAT3 pathway and apoptosis was investigated. Genipin suppressed the constitutive STAT3 activation in U266 and U937 cells and stimulated Src homology 2 domain-containing phosphatase 1 (SHP-1), which dephosphorylates and inactivates STAT3. Specifically, genipin blocked STAT3 activation via repressing the activation of c-Src, but not Janus kinase 1 (JAK1). Genipin also downregulated the expression of STAT3 target genes including Bcl-2, Bcl-x(L) , Survivin, Cyclin D1, and VEGF. Conversely, protein tyrosine phosphatase inhibitor pervanadate blocked genipin induced STAT3 inactivation. Using DNA fragmentation or TUNEL assays, we demonstrated the apoptotic effect of genipin on U266, MM.1S, and U937 cells. Furthermore, genipin effectively potentiated the cytotoxic effect of chemotherapeutic agents, such as bortezomib, thalidomide, and paclitaxel in U266 cells. Our data suggest that through regulation of Src and SHP-1, genipin antagonizes STAT3 for the induction of apoptosis in myeloma cells.

• Suppression of STAT3 and HIF-1 alpha mediates anti-angiogenic activity of betulinic acid in hypoxic PC-3 prostate cancer cells.

  Authors: Jimin Shin, Hyo-Jeong Lee, Deok-Beom Jung, Ji Hoon Jung, Hyo-Jung Lee, Eun-Ok Lee, Seok Geun Lee, Beom Sang Shim, Seung Hoon Choi, Seong Gyu Ko, Kwang Seok Ahn, Soo-Jin Jeong, Sung-Hoon Kim

  PloS one. 01/2011; 6(6):e21492.

  Signal transducer and activator of transcription 3 (STAT3) is a transcription factor that regulates various cellular processes such as cell survival, angiogenesis and proliferation. In the presentSignal transducer and activator of transcription 3 (STAT3) is a transcription factor that regulates various cellular processes such as cell survival, angiogenesis and proliferation. In the present study, we examined that betulinic acid (BA), a triterpene from the bark of white birch, had the inhibitory effects on hypoxia-mediated activation of STAT3 in androgen independent human prostate cancer PC-3 cells. BA inhibited the protein expression and the transcriptional activities of hypoxia-inducible factor-1α (HIF-1α) under hypoxic condition. Consistently, BA blocked hypoxia-induced phosphorylation, DNA binding activity and nuclear accumulation of STAT3. In addition, BA significantly reduced cellular and secreted levels of vascular endothelial growth factor (VEGF), a critical angiogenic factor and a target gene of STAT3 induced under hypoxia. Furthermore, BA prevented in vitro capillary tube formation in human umbilical vein endothelial cells (HUVECs) maintained in conditioned medium of hypoxic PC-3 cells, implying anti-angiogenic activity of BA under hypoxic condition. Of note, chromatin immunoprecipitation (ChiP) assay revealed that BA inhibited binding of HIF-1α and STAT3 to VEGF promoter. Furthermore, silencing STAT3 using siRNA transfection effectively enhanced the reduced VEGF production induced by BA treatment under hypoxia. Taken together, our results suggest that BA has anti-angiogenic activity by disturbing the binding of HIF-1α and STAT3 to the VEGF promoter in hypoxic PC-3 cells.

• Emodin inhibits proinflammatory responses and inactivates histone deacetylase 1 in hypoxic rheumatoid synoviocytes.

  Authors: Mi-Kyoung Ha, Young Hoon Song, Soo-Jin Jeong, Hyo-Jung Lee, Ji Hoon Jung, Bonglee Kim, Hyo Sook Song, Jeong-Eun Huh, Sung-Hoon Kim

  Biological & pharmaceutical bulletin. 01/2011; 34(9):1432-7.

  Chronic inflammation of rheumatoid arthritis (RA) is promoted by proinflammatory cytokines and closely linked to angiogenesis. In the present study, we investigated the anti-inflammatory effects ofChronic inflammation of rheumatoid arthritis (RA) is promoted by proinflammatory cytokines and closely linked to angiogenesis. In the present study, we investigated the anti-inflammatory effects of emodin (1,3,8-trihydroxy-6-methyl-anthraquinone) isolated from the root of Rheum palmatum L. in interleukin 1 beta (IL-1β) and lipopolysaccharide (LPS)-stimulated RA synoviocytes under hypoxia. Emodin significantly inhibited IL-1β and LPS-stimulated proliferation of RA synoviocytes in a dose-dependent manner under hypoxic condition. Also, enzyme linked immunosorbent assay (ELISA) revealed that emodin significantly reduced the production of pro-inflammatory cytokines [tumor necrosis factor-alpha (TNF-α), IL-6 and IL-8], mediators [prostagladin E(2) (PGE(2)), matrix metalloproteinase (MMP)-1 and MMP-13] and vascular endothelial growth factor (VEGF) as an angiogenesis biomarker in IL-1β and LPS-treated synoviocytes under hypoxia. Consistently, emodin attenuated the expression of cyclooxygenase 2 (COX-2), VEGF, hypoxia inducible factor 1 alpha (HIF-1α), MMP-1 and MMP-13 at mRNA level in IL-1β and LPS-treated synoviocytes under hypoxia. Furthermore, emodin reduced histone deacetylase (HDAC) activity as well as suppressed the expression of HDAC1, but not HDAC2 in IL-1β and LPS-treated synoviocytes under hypoxia. Overall, these findings suggest that emodin inhibits proinflammatory cytokines and VEGF productions, and HDAC1 activity in hypoxic RA synoviocytes.

• Paeonol oxime inhibits bFGF-induced angiogenesis and reduces VEGF levels in fibrosarcoma cells.

  Authors: Hyo-Jeong Lee, Seung-Ae Kim, Hyo-Jung Lee, Soo-Jin Jeong, Ihn Han, Ji Hoon Jung, Eun-Ok Lee, Shudong Zhu, Chang-Yan Chen, Sung-Hoon Kim

  PloS one. 01/2010; 5(8):e12358.

  We previously reported the anti-angiogenic activity of paeonol isolated from Moutan Cortex. In the present study, we investigated the negative effect of paeonol oxime (PO, a paeonol derivative) onWe previously reported the anti-angiogenic activity of paeonol isolated from Moutan Cortex. In the present study, we investigated the negative effect of paeonol oxime (PO, a paeonol derivative) on basic fibroblast growth factor (bFGF)-mediated angiogenesis in human umbilical vein endothelial cells (HUVECs) (including tumor angiogenesis) and pro-survival activity in HT-1080 fibrosarcoma cell line. We showed that PO (IC(50) = 17.3 microg/ml) significantly inhibited bFGF-induced cell proliferation, which was achieved with higher concentrations of paeonol (IC(50) over 200 microg). The treatment with PO blocked bFGF-stimulated migration and in vitro capillary differentiation (tube formation) in a dose-dependent manner. Furthermore, PO was able to disrupt neovascularization in vivo. Interestingly, PO (25 microg/ml) decreased the cell viability of HT-1080 fibrosarcoma cells but not that of HUVECs. The treatment with PO at 12.5 microg/ml reduced the levels of phosphorylated AKT and VEGF expression (intracellular and extracelluar) in HT-1080 cells. Consistently, immunefluorescence imaging analysis revealed that PO treatment attenuated AKT phosphorylation in HT-1080 cells. Taken together, these results suggest that PO inhibits bFGF-induced angiogenesis in HUVECs and decreased the levels of PI3K, phospho-AKT and VEGF in HT-1080 cells.

• A Design of the Frequency Synthesizer for UWB Application in 0.13 µm RF CMOS Process

  Authors: JinKyung Kim, Sung-Kyu Jung, Ji-Hoon Jung, Sang-Kyung Sung, Kang-Yoon Lee, Chul Nam, Bong-Hyuk Park, Sang-sung Choi

  Electronic Design, Test and Applications, 2008. DELTA 2008. 4th IEEE International Symposium on; 02/2008

  This paper describes a 3 to 5 GHz frequency synthesizer for MB-OFDM (multi-band OFDM) UWB (Ultra- Wideband) application using 0.13 um CMOS process. The frequency synthesizer operates in the bandThis paper describes a 3 to 5 GHz frequency synthesizer for MB-OFDM (multi-band OFDM) UWB (Ultra- Wideband) application using 0.13 um CMOS process. The frequency synthesizer operates in the band group 1 whose center frequencies are 3432 MHz, 3960 MHz, and 4488 MHz. To cover the overall frequencies of group 1, an efficient frequency planning minimizing a number of blocks and the power consumption are proposed. And, a high-frequency VCO and prescaler architecture are also presented in this paper. A new coarse tuning scheme that utilizes the MIM capacitance and the varactor is proposed to expand the VCO tuning range. The single PLL and two SSB-mixers consume 75 mW from a 1.5 V supply. The VCO tuning range is 500 MHz. The simulated phase noise of the VCO is -110 dBc/Hz at 1 MHz offset. The die area is 3 times 2 mm².

• A Design of 14-bits ¿¿ ADC and DAC for CODEC Applications in 0.18 ¿ m CMOS process

  Authors: Dong-Hyun Ko, Ji-Hoon Jung, Young Gun Pu, Chul Nam, Kang-Yoon Lee

  Radio-Frequency Integration Technology, 2007. RFIT 007. IEEE International Workshop on; 01/2008

  This paper presents a sigma-delta modulation ADC (analog-to-digital converter) and DAC (digital-to-analog converter) for CODEC applications using 0.18 mum CMOS process. In the ADC parts, twoThis paper presents a sigma-delta modulation ADC (analog-to-digital converter) and DAC (digital-to-analog converter) for CODEC applications using 0.18 mum CMOS process. In the ADC parts, two sigma-delta modulators with 84 dB SNR are designed for the stereo applications, and their outputs are merged at the digital domain before decimation filter. Digital decimation filter is integrated with the analog sigma-delta modulators for the full ADC operation. In the DAC parts, the digital data is first processed at the interpolator filters, and modulated by the following sigma-delta modulators. To reduce the mismatch effect of the following DAC, the dynamic element matching method is proposed in this paper. It is designed with 0.18 mum CMOS process. The simulated SNR is about 100 dB. and the power consumption is 40 mA.

• A Design of the Frequency Synthesizer for UWB Application in 0.13 ¿m RF CMOS process

  Authors: Jin-Kyung Kim, Sung-Kyu Jung, Ji-Hoon Jung, Kang-Yoon Lee, Chul Nam, Bong-Hyuk Park, Sang-sung Choi

  Radio-Frequency Integration Technology, 2007. RFIT 007. IEEE International Workshop on; 01/2008

  This paper describes a 3 to 5 GHz frequency synthesizer for MB-OFDM (multi-band OFDM) UWB (Ultra-Wideband) application using 0.13 um CMOS process. The frequency synthesizer operates in the band groupThis paper describes a 3 to 5 GHz frequency synthesizer for MB-OFDM (multi-band OFDM) UWB (Ultra-Wideband) application using 0.13 um CMOS process. The frequency synthesizer operates in the band group 1 whose center frequencies are 3432 MHz, 3960 MHz, and 4488 MHz. To cover the overall frequencies of group 1, an efficient frequency planning minimizing a number of blocks and the power consumption are proposed. And, a high-frequency VCO and prescaler architecture are also presented in this paper. A new coarse tuning scheme that utilizes the MIM capacitance and the varactor is proposed to expand the VCO tuning range. The single PLL and two SSB-mixers consume 75 mW from a 1.5 V supply. The VCO tuning range is 500 MHz. The simulated phase noise of the VCO is -110 dBc/Hz at 1 MHz offset. The die area is 3 x 2 mm².

• A Design of 14-bits ADC and DAC for CODEC Applications in 0.18 µm CMOS Process.

  Authors: DongHyun Ko, Ji-Hoon Jung, YoungGun Pu, Sang-Kyung Sung, Kang-Yoon Lee, Chul Nam

  4th IEEE International Symposium on Electronic Design, Test and Applications, DELTA 2008, Hong Kong, January 23-25, 2008; 01/2008

• [Comparison of clinical findings between autoimmune pancreatitis with bile duct involvement and primary sclerosing cholangitis]

  Authors: Ja Young Kim, Myung-Hwan Kim, Ji Hoon Jung, Ju Hyung Song, Hyoung-Chul Oh, Seung Hyun Kwon, Tae Yoon Lee, Sang Soo Lee, Dong Wan Seo, Sung Koo Lee

  The Korean journal of gastroenterology = Taehan Sohwagi Hakhoe chi. 09/2006; 48(2):104-11.

  BACKGROUND/AIMS: The involvement of bile ducts is frequently reported in autoimmune pancreatitis (AIP), which seem to have similar features to primary sclerosing cholangitis (PSC). Recent systematicBACKGROUND/AIMS: The involvement of bile ducts is frequently reported in autoimmune pancreatitis (AIP), which seem to have similar features to primary sclerosing cholangitis (PSC). Recent systematic comparative studies about these diseases are rare in Korea. METHODS: We retrospectively analyzed 26 patients with AIP with bile duct involvement and 30 patients with classic PSC who were diagnosed during the last decade. RESULTS: The mean age of patients was significantly higher in AIP than PSC at the time of diagnosis. There was a preponderance of men in both group, which was more prominent in AIP. The most common symptom in patients with AIP was jaundice, but PSC patients usually visited hospitals due to incidentally detected abnormal liver function tests. Most (26/31) of AIP had bile duct involvement. All of these patients showed narrowing of intrapancreatic common bile ducts and one patient exhibited hilar involvement as well. About 80% of PSC had both intra- and extrahepatic ducts involvement, and the characteristic features involve multifocal strictures. AIP patients showed improvement with steroid treatment, however, most PSC patients showed clinical deterioration. CONCLUSIONS: The clinical and cholangiographic findings of patients with AIP and PSC have many different characteristics. Therefore, further study of two diseases is required for the proper diagnosis and management.

• [Thirteen cases of intrahepatic biliary cystadenoma and cystadenocarcinoma: a single center experience]

  Authors: Tae Hoon Oh, Myung-Hwan Kim, Sung Koo Lee, Dong Wan Seo, Sang Soo Lee, Eui Young Kim, Ju Hyung Song, Ji Hoon Jung, Sang-Ah Lee, Sung-Gyu Lee, So Hyung Park, Se Jin Jang

  The Korean journal of gastroenterology = Taehan Sohwagi Hakhoe chi. 06/2006; 47(5):379-85.

  BACKGROUND/AIMS: Biliary cystadenoma (BCA) and biliary cystadenocarcinoma (BCACa) are rare cystic neoplasms that usually arise from the liver. We reviewed the clinicopathologic and radiologicBACKGROUND/AIMS: Biliary cystadenoma (BCA) and biliary cystadenocarcinoma (BCACa) are rare cystic neoplasms that usually arise from the liver. We reviewed the clinicopathologic and radiologic findings of 13 cases of intrahepatic biliary cystic neoplasms. METHODS: Seven patients with BCA and 6 patients with BCACa which were pathologically proven within past 10 years were included in this retrospective study. RESULTS: BCA (7 of 7) was more common in female compared to BCACa (4 of 6). Mean age at diagnosis was 53.4 years (BCA) and 58.5 years (BCACa). Abdominal pain (54%) was the most common presenting symptom. Eleven patients (61.5%) exhibited normal liver function profiles and 5 patients (38%) showed elevated levels of serum CA19-9 levels (mean 894.2 U/mL, range: 78.7-2,080). Mean size of tumor was 11.7 cm (range: 5-15). Most frequent radiologic finding was a single cystic mass with septation. BCACa tended to have intracystic solid portion. The cut surface revealed a unilocular or multilocular cystic mass with mucinous contents. Complete surgical excision was done in 12 patients. After the complete resection, recurrence was observed in 1 case of BCACa. CONCLUSIONS: The possibility of biliary cystic neoplasm should be suspected when an intrahepatic cystic lesion with multiseptation or solid portion is noted on imaging study. In addition, complete excision for definite diagnosis and treatment need to be performed.

• Herbal cocktail ka-mi-kae-kyuk-tang stimulates mouse bone marrow stem cell hematopoiesis and janus-activated kinase 2/signal transducer and activator of transcription 5 pathway.

  Authors: Jeong-Eun Lee, Inweon Seo, Soo-Jin Jeong, Wonil Koh, Ji Hoon Jung, Tae-Rin Kwon, Hyo-Jung Lee, Ihn Han, Hyo-Jeong Lee, Eun-Ok Lee, Sun-Hyung Kim, Hee-Jae Jung, Junxuan Lu, Sung-Hoon Kim

  The American journal of Chinese medicine. 39(6):1235-52.

  Ka-mi-kae-kyuk-tang (KMKKT) is an Oriental herbal medicinal cocktail. Our collaborative team has shown that it has potent anti-angiogenic, anti-cancer and anti-metastatic activities in vivo withoutKa-mi-kae-kyuk-tang (KMKKT) is an Oriental herbal medicinal cocktail. Our collaborative team has shown that it has potent anti-angiogenic, anti-cancer and anti-metastatic activities in vivo without observable side effects. We have documented evidence for KMKKT to alleviate drug-induced hematotoxicity in vivo. In the present study, we investigated the mechanistic and signaling events through which KMKKT enhances hematopoiesis, using hematopoietic stem cells (HSCs) isolated from the bone marrow of 8-12 week-old C57BL/6 mice. Our results show that KMKKT significantly increased the expression of the hematopoietic cytokines interleukin (IL)-3, stem cell factor (SCF), granulocyte-macrophage-colony stimulating factor (GM-CSF), thrombopoietin (TPO) and erythropoietin (EPO) at the level of mRNA and secretion in HSCs. KMKKT also increased the expression of c-Kit, a cytokine receptor expressed in HSCs. In addition, KMKKT enhanced phosphorylation of Janus kinase 2 (JAK2) and signal transducer and activator of transcription 5 (STAT5), and increased the binding activity of STAT5 to gamma interferon activated sites (GAS) that mediate JAK2 downstream signaling. Furthermore, we found that KMKKT significantly enhanced the growth rate of colony-forming unit granulocyte erythrocyte monocyte macrophages (CFU-GEMM) and burst forming unit erythroid (BFU-E) of mouse HSCs (mHSCs) stimulated by IL-3/EPO. Overall, our results demonstrated that KMKKT alleviated drug-induced side effects through enhanced hematopoiesis, at least in part through cytokine-mediated JAK2/STAT5 signaling.