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ABSTRACT: The BRAF T1799A mutation is a heterozygous point mutation and its reported prevalence in papillary thyroid carcinoma (PTC) has varied from 29 to 83%, with an overall mean of 44%. In Korea, the reported mutation rate reached 83% in PTC and 52% in micropapillary carcinoma. We hypothesized that the differences in prevalence may be influenced by the methods of mutation analysis, the sizes of tumor and ethnic differences. Three types of DNA samples from the same PTC mass (0.4-1.6 cm, mean 0.83 cm sized) per each patient (n=17) were isolated. The first type was obtained from frozen PTC tissues using laser-captured microdissection (Frozen-laser, n=17), the second was obtained from frozen tissue by manual tumor margin dissection using a blade (Frozen-blade, n=17) and the third was obtained from formalin-fixed, paraffin-embedded tissue by manual margin dissection (Paraffin-blade, n=15, 2 failed). The mutation rates of the three-matched DNA samples were compared by the SNP mode and AQ mode of pyrosequencing, and direct DNA sequencing. Both the AQ mode of pyrosequencing and the direct DNA sequencing detected the BRAF T1799A mutation in 100% of the 'Frozen-laser' samples, but the mutation was omitted in 1/17 of the 'Frozen-blade' samples and in 5/15 of the 'Paraffin-blade' samples, while the former was more rapid and objective than the latter. The SNP mode of pyrosequencing variably detected the mutation from 40 to 100%, and it showed the lowest sensitivity. Our results indicate that the reported prevalence of the BRAF T1799A mutation in PTC can be underestimated due the mutation analysis methods, and especially in small PTCs. The BRAF T1799A mutation may be an early and essential carcinogenic event in nearly all Korean PTCs, and even in micro-PTCs. For the accurate detection of the BRAF T1799A mutation from small PTCs, fresh or frozen tissues and more cautious microdissection are required, and the AQ mode of pyrosequencing assay is preferred.
Oncology Reports 03/2011; 25(6):1639-44. · 1.84 Impact Factor
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ABSTRACT: For the seamless video streaming, the bandwidth variation should be considered to control the transmission rate. The packet pair probing technique (PPPT) can be utilized to measure the bandwidth of the network. To adapt the PPPT to the video streaming over the high speed downlink packet access (HSDPA), we experimentally investigate the relationship between the actual available bandwidth (AB) of the HSDPA network and the channel capacity estimated by the PPPT. Using this relationship, we propose an efficient real-time video streaming method. Experimental results show that the proposed method improves the performance of the video streaming over the HSDPA network.
Consumer Electronics, 2009. ICCE '09. Digest of Technical Papers International Conference on; 02/2009
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IEEE Trans. Circuits Syst. Video Techn. 01/2009; 19:1902-1907.
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ABSTRACT: During follicular development, the importance of the interaction between oocytes and somatic cells is well-known for maturation oocyte. Growth differentiation factor-9 (gdf-9) is thought to play an important role in such process. In this study, we characterized porcine gdf-9 gene and investigate its expression during development. Also we determined its expression by different hormones during in vitro oocyte maturation. Overall length of pig gdf-9 cDNA was cloned and its presumptive protein sequence of isolated cDNA has high homology to human or mouse GDF-9 sequences. The gdf-9 transcript was expressed in all stage of preimplantation embryos and fetuses, and was also expressed in the heart, brain, cumulus cells, spleen, ovary, and testis. Porcine GDF-9 protein was specifically localized in in vitro matured oocyte and oocytes from adult ovary. In order to investigate the potential regulator of gdf-9 gene expression, expression level of gdf-9 gene was determined using serum-free in vitro maturation (IVM) system. Supplementing with human chorionic gonadotrophin (hCG), pregnant mare serum gonadotrophin (PMSG), gonadotropin-releasing hormone (GnRH), follicular stimulating hormone, luteinizing hormone (LH), or epidermal growth factor (EGF) did not affect level of gdf-9 gene expression during ooycte maturation. In conclusion, porcine gdf-9 gene is expressed in the porcine reproductive organ, especially in oocytes and embryos, and its expression is decreased during IVM.
Molecular Reproduction and Development 06/2008; 75(5):707-14. · 2.53 Impact Factor
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ABSTRACT: The channel bandwidth variation and the disconnection during handoff are the most critical problems which degrade the video quality in wireless video streaming. To cope with these problems, we propose an efficient video streaming method in this paper, which does not only dynamically adjust the video transmission rate based on the channel bandwidth, but also minimize the error propagation during handoff. First, the channel bandwidth of the mobile worldwide interoperability for microwave access, called WiMAX, is estimated by analyzing channel parameters including the carrier to interference and noise ratio (CINR) and the handoff is detected by using the handoff occurrence message (HOM). Second, the streaming server adjusts the next transmission rate according to the estimated channel bandwidth to avoid the network congestion and performs the intra refresh method that inserts an intra frame (l-frame) right after handoff by using the HOM to reduce the error propagation effectively. Experimental results indicate that the proposed method can improve the performance of the video streaming over mobile WiMAX.
IEEE Transactions on Consumer Electronics 03/2008; · 0.94 Impact Factor
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ABSTRACT: This paper presents a channel-aware video streaming method that does not only adjust dynamically the target bit rate according to the channel condition but also minimize the error propagation at handoff. The proposed method performs adaptive bit rate allocation (ABA) by using the carrier to interference and noise ratio (CINR) to reduce the packet loss ratio (PLR) without wasting the channel resource. Moreover, adaptive intra refresh (AIR) is performed to reduce the error propagation when the handoff is occurred. Experimental results indicate that the proposed method can be successfully used for video streaming over WiBro networks.
Consumer Electronics, 2008. ICCE 2008. Digest of Technical Papers. International Conference on; 02/2008
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ABSTRACT: In general, methylation of the promoter regions is inversely correlated with gene expression. The transitional CpG area between the promoter-associated CpG islands and the nearby retroelements is often methylated in a tissue-specific manner. This study analyzed the relationship between gene expression and the methylation of the transitional CpGs in two human stromal cells derived from the bone marrow (BMSC) and adipose tissue (ATSC), both of which have a multilineage differentiation potential. The transitional CpGs of the osteoblast-specific (RUNX2 and BGLAP), adipocyte-specific (PPARgamma2), housekeeping (CDKN2A and MLH1), and mesenchyme-unrelated (RUNX3) genes were examined by methylation-specific PCR. The expression of each gene was measured using reverse-transcription PCR analysis. The RUNX2, BGLAP, and CDKN2A genes in the BMSC, and the PPARgamma2 gene in the ATSC exhibited hypomethylation of the transitional CpGs along with the strong expression. The CpG island of RUNX3 gene not expressed in both BMSC and ATSC was hypermethylated. Transitional hypomethylation of the MLH1 gene was accompanied by the higher expression in the BMSC than in the ATSC. The weakly methylated CpGs of the PPARgamma2 gene in the BMSC became hypomethylated along with the strong expression during the osteoblastic differentiation. There were no notable changes in the transitional methylation and expression of the genes other than PPARgamma2 after the differentiation. Therefore, the transitional methylation and gene expression established in mesenchymal cells tend to be consistently preserved under the induction of differentiation. Weak transitional methylation of the PPARgamma2 gene in the BMSC suggests a methylation-dependent mechanism underlying the adiopogenesis of bone marrow.
Journal of Cellular Biochemistry 10/2007; 102(1):224-39. · 2.87 Impact Factor
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ABSTRACT: The paper presents a fast homogenous H.264 video transcoding algorithm in order to reduce the bitrate. We propose a fast mode decision algorithm by using the frame activity based on motion vector (MV) in input bitstream. In the proposed algorithm, the frame activity reflects a degree of macroblock (MB) mode variation between pre-coded bitstream and transcoded bitstream which degrades the rate-distortion (RD) performance significantly due to variable block size in H.264. Experimental results show that the proposed algorithm can be effectively applied to the H.264 video transcoder for the lower complexity and the better quality
Communications and Information Technologies, 2006. ISCIT '06. International Symposium on; 10/2006
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ABSTRACT: Consumers increasingly demand high quality of service (QoS) for multimedia applications. Rate control scheme is one of the
major methods that provide high video quality for mobile multimedia devices over wireless networks. This paper presents an
efficient rate-control scheme which estimates the transmission power level of mobile devices, then adaptively adjusts the
encoding bit rate according to the estimated power level to minimize overall distortion over sequences of video frames. Experimental
results show that the proposed method can efficiently enhance the video quality and provide better peak signal to noise ratio
(PSNR) performance than existing TMN8 rate control method.
07/2006: pages 458-471;
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ABSTRACT: Alu and L1 retroelements have been suggested to initiate the spread of CpG methylation. In this study, the spread of CpG methylation was estimated based on the distance between the CpG islands and the nearest retroelements. All human genes (23,116) were examined and the correlations between the length of the CpG islands and the distance and density of the confronting retroelements were examined using nonoverlapping 5-kb windows. There was a linear relationship between the length of the CpG islands and the density of the Alu elements and an inverse relationship between the CpG islands and the L1 elements located more distantly, suggesting a suppressive effect of the Alu's on the spread of L1 methylation. Methylation analysis of the transitional CpG sites between the CpG islands and the nearest retroelements upstream of 16 genes was then carried out using DNA preparations from 11 different human tissues. Methylation-variable transitional CpGs were observed for the selected genes and the different tissues.
Genomics 06/2006; 87(5):580-90. · 3.02 Impact Factor
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ABSTRACT: The present study investigated the expression of ligand and receptor for leptin, and the effect of leptin supplementation on preimplantation development of porcine in vitro fertilized (IVF) and somatic cell nuclear transfer (SCNT) embryos. The IVF embryos were produced using frozen boar semen and SCNT embryos were obtained by nuclear transfer of fetal fibroblasts into enucleated oocytes. The protein expression of leptin ligand and receptor was investigated in in vitro matured oocytes, 2-, 4- and 8-cell embryos, morulae and blastocysts derived from IVF and SCNT using immunofluorescence. Both the ligand and receptor were detected in in vitro matured oocytes and all stage of IVF and SCNT embryos. The IVF and SCNT embryos were cultured in modified North Carolina State University (mNCSU)-23 medium supplemented with various concentrations (0, 1, 10, 100 or 1000 ng/mL) of leptin. The rates of cleavage at day 2 and blastocyst formation at day 7, and cell number of blastocysts were monitored as experimental parameters. In SCNT embryos, supplementing with 1000 ng/mL leptin significantly (P<0.05) increased the rate of blastocysts formation (20.2% versus 12.9%) and total cell number (54.6+/-17.4 versus 45.1+/-15.2) compared to the control group. In IVF embryos, leptin supplementation did not affect preimplantation embryo development and cell number in blastocysts. In conclusion, the present study demonstrated the expression of leptin ligand and receptor and the embryotropic effect of leptin in SCNT embryos.
Theriogenology 03/2006; 65(4):831-44. · 1.96 Impact Factor
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ABSTRACT: Vertical handoff (VH) is required to achieve anywhere and anytime internet access in the fourth generation (4G) network providing
interoperability between universal mobile telecommunications system (UMTS) and wireless LAN (WLAN). However, video data can
be lost due to latency caused by VH. To solve this problem, in this paper, we propose an effective video streaming method
for video on demand (VOD) services that provides seamless playout at the client in VH. Experimental results show that our
method can provide seamless playout at the client in VH while preserving image quality.
02/2006: pages 397-406;
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ABSTRACT: This paper presents a power-aware rate control method that dynamically adjusts the encoding bit rate according to the receiving power level of mobile stations (MSs) in CDMA network. The proposed rate-control method performs bit allocation at the video frame level using the estimated channel bit rate to minimize the average distortion over wireless video transmission. Experimental results show that the proposed method can significantly enhance the video quality in CDMA networks.
Consumer Electronics, 2006. ICCE '06. 2006 Digest of Technical Papers. International Conference on; 02/2006
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ABSTRACT: The superior temporal gyrus (STG) may be involved in the pathophysiology of obsessive-compulsive disorder (OCD). Moreover, the anterior STG has rich interconnections with the orbitofrontal cortex and the amygdala, and plays a role in visuospatial processing, which is impaired in patients with OCD. This study was designed to examine the morphological abnormalities of the anterior STG and their relationships with visuospatial function and clinical symptom in patients with OCD. We measured gray matter volumes of the anterior STG [rostral STG and planum polare (PP)] by three-dimensional (3D) magnetic resonance imaging in age- and sex-matched groups, which consisted of 22 patients with OCD and 22 normal volunteers. Visuospatial function and clinical symptom were assessed using the Rey-Osterrieth Complex Figure (ROCF) test, the Yale-Brown Obsessive Compulsive Scale, and the Maudsley Obsessive Compulsive Inventory. We found significant volume reductions in bilateral PPs, but there were no significant correlations between brain volumes and the ROCF copy score, immediate or delayed recall score, and clinical symptom in patients with OCD. These results suggest that volume reduction of the anterior STG, especially the PP, may be related to the pathophysiology of OCD, but further research may be needed to explore a relationship of the PP volume change with cognitive impairment observed in patients with OCD.
Depression and Anxiety 02/2006; 23(5):290-6. · 4.18 Impact Factor
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Ad-Hoc, Mobile, and Wireless Networks, 5th International Conference, ADHOC-NOW 2006, Ottawa, Canada, August 17-19, 2006, Proceedings; 01/2006
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IEICE Transactions. 01/2006; 89-A:1571-1577.
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Advances in Image and Video Technology, First Pacific Rim Symposium, PSIVT 2006, Hsinchu, Taiwan, December 10-13, 2006, Proceedings; 01/2006
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NETWORKING 2006 - Networking Technologies, Services, and Protocols; Performance of Computer and Communication Networks; Mobile and Wireless Communications Systems, 5th International IFIP-TC6 Networking Conference, Coimbra, Portugal, May 15-19, 2006, Proceedings; 01/2006
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Jung-Seok Choi M.D,
Hye-Soo Kim B.A,
So Young Yoo M.D,
Tae-Hyun Ha M.D,
Joon-Hwan Chang M.D,
Young Youn Kim Ph.D,
Yong-Wook Shin M.D,
Ph.D. Jun Soo Kwon M.D,
Jung‐Seok Choi, Hye‐Soo Kim,
So Young Yoo,
Tae‐Hyun Ha,
Joon‐Hwan Chang,
Young Youn Kim,
Yong‐Wook Shin,
Jun Soo Kwon
[show abstract]
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ABSTRACT: The superior temporal gyrus (STG) may be involved in the pathophysiology of obsessive–compulsive disorder (OCD). Moreover, the anterior STG has rich interconnections with the orbitofrontal cortex and the amygdala, and plays a role in visuospatial processing, which is impaired in patients with OCD. This study was designed to examine the morphological abnormalities of the anterior STG and their relationships with visuospatial function and clinical symptom in patients with OCD. We measured gray matter volumes of the anterior STG [rostral STG and planum polare (PP)] by three-dimensional (3D) magnetic resonance imaging in age- and sex-matched groups, which consisted of 22 patients with OCD and 22 normal volunteers. Visuospatial function and clinical symptom were assessed using the Rey–Osterrieth Complex Figure (ROCF) test, the Yale–Brown Obsessive Compulsive Scale, and the Maudsley Obsessive Compulsive Inventory. We found significant volume reductions in bilateral PPs, but there were no significant correlations between brain volumes and the ROCF copy score, immediate or delayed recall score, and clinical symptom in patients with OCD. These results suggest that volume reduction of the anterior STG, especially the PP, may be related to the pathophysiology of OCD, but further research may be needed to explore a relationship of the PP volume change with cognitive impairment observed in patients with OCD. Depression and Anxiety 23:290–296, 2006. © 2006 Wiley-Liss, Inc.
Depression and Anxiety 12/2005; 23(5):290 - 296. · 4.18 Impact Factor
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ABSTRACT: The vasa gene is known to be an important factor for germ cell development in both invertebrates and vertebrates. In the present study, we cloned the porcine vasa homolog (Pvh, 2,172 bps) and investigated its expression at mRNA and protein levels. The isolated cDNA had deduced 724 amino acid residues with significant homology to mouse (85%) and human (91%) vasa. In adult tissues, Pvh transcript was restricted to the ovary and testis, and was undetectable in somatic tissues. During preimplantation embryo development, Pvh was transcribed in oocytes and fertilized 2-cell embryos, but not in other preimplantation embryos. In fetal stage, the transcript of Pvh gene was expressed in all fetal stage, except in day 17-18. Immunohistochemical analysis of fetal and adult gonad revealed that the Pvh protein was localized in oocytes and spermatocytes, consistent with mRNA expression. Interestingly, Pvh protein was also observed in proliferating primordial germ cells (PGCs) and freshly isolated PGCs, but not in embryonic germ cells. Our results suggest that Pvh gene can be a useful marker for germ cell development in pigs.
Molecular Reproduction and Development 12/2005; 72(3):320-8. · 2.53 Impact Factor
