• Title/Summary/Keyword: Choi Chang Hak

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Identification of Polymorphisms of Fas Gene and Association Analysis in Hanwoo

  • Kim, Seung-Chang;Lee, Seung-Hwan;Kim, Bum-Soo;Kim, Tae-Hun;Seong, Hwan-Hoo;Oh, Sung-Jong;Yoon, Du-Hak;Choi, Bong-Hwan
    • Journal of Animal Science and Technology
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    • v.53 no.6
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    • pp.511-516
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    • 2011
  • Fas gene known to associate with intramuscular fat content in Korean cattle was selected for DNA marker development. Fas (APO-1, CD95), a member of the tumor necrosis factor (TNF) receptor superfamily, is a cell membrane protein that mediates apoptosis (programmed cell death). We discovered single nucleotide polymorphisms (SNPs) within Fas gene in order to develop novel DNA markers at genomic level. Of this gene to search for SNP, sequences of whole exon and 1kb range of both front and back of the gene using 24 cattle were determined by direct-sequencing methods. As a result, 16 SNPs in exon, 37 SNPs in intron and 2 SNPs in promoter region, a total of 55 SNPs were discovered. In these SNPs, thirty-one common polymorphic sites were selected considering their allele frequencies, haplotype-tagging status and Linkage Disequilibrium (LD) for genotyping in larger-scale subjects. Selected SNPs were confirmed genotype through SNaPshot method (n=274) and were examined for possible genetic association of Fas polymorphisms with carcass weight (CWT), eye muscle area (EMA), and backfat thickness (BF). So, the SNP have been identified significant g.-12T>G, g.1112T>G and g.32548T>C. These results suggest that polymorphism of Fas gene was associated with meat quality traits in Hanwoo.

Differential Effects of Nitric Oxide Synthase Inhibitors in Rats

  • Lee, Jun-Hee;Shin, Chang-Yell;Kang, Bong-Su;Jeong, Ji-Hoon;Choi, Kyeong-Bum;Min, Young-Sil;Kim, Jin-Hak;Huh, In-Hoi;Sohn, Uy-Dong
    • The Korean Journal of Physiology and Pharmacology
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    • v.4 no.2
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    • pp.99-104
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    • 2000
  • We investigated the action of NOS inhibitors on NOS in rats. Both of nitric oxide synthase inhibitors, $N^G$-monomethyl-L-arginine $(L-NMMA,\;3\;{\mu}M)$ or $N^G$-nitro-L-arginine methylester $(L-NAME,\;30\;{\mu}M),$ augmented phenylephrine $(PE,\;10^{-7}\;M)-induced$ contraction which was inhibited by acetylcholine (ACh) in rat thoracic aorta. This augmentation by L-NAME or L-NMMA was attenuated with the treatment of NO precursor, arginine. ACh, however, decreased the augmentation induced by L-NMMA, but not by L-NAME. Superoxide dismutase (SOD, 50 u/ml) potentiated an inhibitory effect of ACh on the PE $(10^{-7}\;M)-induced$ contraction. It has been known that platelet activating factor itself induces iNOS. Platelet activating factor $(PAF,\;10^{-7}\;M)$ inhibited PE $(10^{-7}\;M)-induced$ contraction. Pretreatment with L-NMMA (30 mM) or L-NAME (30 mM) significantly blocked the inhibitory action of PAF on PE-induced contraction. L-NMMA (100 mM) or L-NAME (100 mM) reduced nerve conduction velocity (NCV) relevant to nNOS in rat sciatic nerve. ACh attenuated the reduction of NCV by L-NMMA-, but not by L-NAME-induced reduction of NCV. These results suggest that L-NMMA and/or L-NAME have different action on three types of NOS in rats.

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Factors Affecting the Efficiency of Animal Cloning by Somatic Cell Nuclear Transfer

  • Kim, Min-Goo;Park, Chi-Hun;Lee, Sang-Goo;Seo, Hee-Won;Choi, Yo-Han;Lee, Chang-Kyu;Ka, Hak-Hyun
    • Journal of Embryo Transfer
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    • v.23 no.2
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    • pp.67-76
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    • 2008
  • Since the birth of Dolly using fully differentiated somatic cells as a nuclear donor, viable clones were generated successfully in many mammalian species. These achievements in animal cloning demonstrate developmental potential of terminally differentiated somatic cells. At the same time, the somatic cell nuclear transfer (SCNT) technique provides the opportunities to study basic and applied biosciences. However, the efficiency generating viable offsprings by SCNT remains extremely low. There are several explanations why cloned embryos cannot fully develop into viable animals and what factors affect developmental potency of reconstructed embryos by the SCNT technique. The most critical and persuasive explanation for inefficiency in SCNT cloning is incomplete genomic reprogramming, such as DNA methylation and histone modification. Numerous studies on genomic reprogramming demonstrated that incorrect DNA methylation and aberrant epigenetic reprogramming are considerably correlated with abnormal development of SCNT cloned embryos even though its mechanism is not fully understood. The SCNT technique is useful in cloning farm animals because pluripotent stem cells are not established in farm animal species. Therapeutic cloning combined with genetic manipulation will help to control various human diseases. Also, the SCNT technique provides a chance to overcome excessive demand for the organs by production of transgenic animals as xenotransplantation resources. Here, we describe the factors affecting the efficiency of generating cloned farm animals by the SCNT technique and discuss future directions of animal cloning by SCNT to improve the cloning efficiency.

Regulation of Transforming Growth Factor ${\beta}1$, Platelet-Derived Growth Factor, and Basic Fibroblast Growth Factor by Silicone Gel Sheeting in Early-Stage Scarring

  • Choi, Jaehoon;Lee, Eun Hee;Park, Sang Woo;Chang, Hak
    • Archives of Plastic Surgery
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    • v.42 no.1
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    • pp.20-27
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    • 2015
  • Background Hypertrophic scars and keloids are associated with abnormal levels of growth factors. Silicone gel sheets are effective in treating and preventing hypertrophic scars and keloids. There has been no report on the change in growth factors in the scar tissue following the use of silicone gel sheeting for scar prevention. A prospective controlled trial was performed to evaluate whether growth factors are altered by the application of a silicone gel sheet on a fresh surgical scar. Methods Four of seven enrolled patients completed the study. Transforming growth factor (TGF)-${\beta}1$, platelet-derived growth factor (PDGF), and basic fibroblast growth factor (bFGF) were investigated immunohistochemically in biopsies taken from five scars at 4 months following surgery. Results In both the epidermis and the dermis, the expression of TGF-${\beta}1$ (P=0.042 and P=0.042) and PDGF (P=0.043 and P=0.042) was significantly lower in the case of silicone gel sheet-treated scars than in the case of untreated scars. The expression of bFGF in the dermis was significantly higher in the case of silicone gel sheet-treated scars than in the case of untreated scars (P=0.042), but in the epidermis, the expression of bFGF showed no significant difference between the groups (P=0.655). Conclusions The levels of TGF-${\beta}1$, PDGF, and bFGF are altered by the silicone gel sheet treatment, which might be one of the mechanisms of action in scar prevention.

Angiomyoma on Face : A Case Report (안면부에 발생한 혈관근종의 치험례 : 증례보고)

  • Choi, Junho;Chang, Hak
    • Korean Journal of Head & Neck Oncology
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    • v.29 no.2
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    • pp.48-50
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    • 2013
  • Angiomyoma is a rare, benign smooth muscle cell tumor. These tumors may be found anywhere in the body. They frequently occur in the lower extremities except venous type. Angiomyoma in the head and neck area is very rare, and only a few cases have been reported. A 63 year-old male patient visited to outpatient clinic due to size-growing nodule-like lesion in the Lt. alar area. Excisional biopsy was done for diagnosis. The lesion was totally excised with 2 mm safety margin. Frozen biopsy of the lesion was requested, and all resection margins were proved negative. To cover the raw surface, full thickness skin grafting was performed. The graft was harvested from Rt. posterior auricular area. Tie over dressing was applyed on Lt. alar area. The graft was well taken and healed without any complication in both short term and long term follow up periods of 2 weeks, 1 month, 2 months, and 6 months. Donor site completed healed without any complications. The leiomyoma is benign tumor originated from smooth muscle, and it can be classified into solid leiomyoma, angiomyoma, and epithelioid leiomyoma. Especially, the angiomyoma consists of smooth muscle cell and blood vessel, and it is originated from the tunica media of blood vessel. Angiomyoma alone frequently occurs in the lower extremities as solitary painless subcutaneous tumor. Venous type of angiomyoma in the oral cavity was reported in other references, but on the facial surface it may be the first case reported as paper. So this report can be very meaningful.

Comparative Analysis of Gene Expression in the Female Reproductive Organs

  • Kim, Min-Goo;Seo, Hee-Won;Choi, Yo-Han;Lee, Chang-Kyu;Ka, Hak-Hyun
    • Journal of Embryo Transfer
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    • v.24 no.2
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    • pp.77-87
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    • 2009
  • To understand molecular and cellular mechanisms of many gene products in the female reproductive organs including the ovary and uterine endometrium as well as during embryo development, researchers have developed and utilized many effective methodologies to analyze gene expression in cells, tissues and animals over the last several decades. For example, blotting techniques have helped to understand molecular functions at DNA, RNA and protein levels, and the reverse transcription-polymerase chain reaction (RT-PCR) method has been widely used in gene expression analysis. However, some conventional methods are not sufficient to understand regulation and function of genes expressed in very complex patterns in many organs. Thus, it is required to adopt more high-throughput and reliable techniques. Here, we describe several techniques used widely recently to analyze gene expression, including annealing control based-PCR, differential display-PCR, expressed sequence tag, suppression subtractive hybridization and microarray techniques. Use of these techniques will help to analyze expression pattern of many genes from small scale to large scale and to compare expression patterns of genes in one sample to another. In this review, we described principles of these methodologies and summarized examples of comparative analysis of gene expression in female reproductive organs with help of those methodologies.

In Vitro Activity of Methyl Gallate Isolated from Galla Rhois Alone and in Combination with Ciprofloxacin Against Clinical Isolates of Salmonella

  • Choi, Jang-Gi;Kang, Ok-Hwa;Lee, Young-Seob;Oh, You-Chang;Chae, Hee-Sung;Jang, Hye-Jin;Kim, Jong-Hak;Sohn, Dong-Hwan;Shin, Dong-Won;Park, Hyun;Kwon, Dong-Yeul
    • Journal of Microbiology and Biotechnology
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    • v.18 no.11
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    • pp.1848-1852
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    • 2008
  • Salmonella remains a primary cause of food poisoning worldwide, and massive outbreaks have been witnessed in recent years. Therefore, this study investigated the antimicrobial activity of methyl gallate (MG), which exhibited good antibacterial activity ($MIC=3.9-125{\mu}g/ml$) against all the bacterial strains tested. In a checkerboard dilution test, MG markedly lowered the MICs of ciprofloxacin (CPFX) against Salmonella. The combined activity of CPFX and MG against Salmonella resulted in fractional inhibitory concentrations (FICs) ranging from 0.0037 to 0.015 and from 0.24 to $7.8{\mu}g/ml$, respectively. Meanwhile, the FIC index ranged from 0.31-0.37, indicating a marked synergistic relationship between CPFX and MG against Salmonella. Time-kill assays also showed a decrease in the CFU/ml between the combination and the more active compound. Therefore, this study demonstrated that MG and CPFX can act synergistically in inhibiting Salmonella in vitro.

APEX(Agricultural Policy/Environmental eXtender) Model: An Emerging Tool for Agricultural Environmental Analyses

  • Kim, Min Kyeong;Choi, Soon Kun;Jung, Goo Buk;Kim, Myung Hyun;Hong, Seong Chang;So, Kyu Ho;Jeong, Jae Hak
    • Korean Journal of Soil Science and Fertilizer
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    • v.47 no.3
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    • pp.187-190
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    • 2014
  • The agricultural policy/Environmental eXtender (APEX) model was developed by the Blackland Research and Extension Center in Temple, Texas. APEX is a flexible and dynamic tool that is capable of simulating a wide array of management practices, cropping systems, and other land uses across a broad range of agricultural landscapes, including whole farms and small watersheds. The model can be configured for novel land management strategies, such as filter strip impacts on pollutant losses from upslope crop fields, vegetated grassed waterways in combination with filter strip impacts, and land application of manure removed from livestock feedlots or waste storage ponds. The APEX model has continually evolved since its inception, and the process of adaptation and modification will likely continue as use of the model expands for an ever-increasing range of environmental problems and conditions. Several improvements to specific model subroutines have already been initiated, while other potential improvements have been identified that will require future research and code modification efforts.

Effects of Boron Applications on Flower Spike Dieback of Statice (Limonium spp.)

  • Choi, Chang-Hak;Jeong, Dong-Chun;Lee, Jin-Jae;Song, Young-Ju;Ahn, Byung-Koo;Lee, Jin-Ho
    • Korean Journal of Soil Science and Fertilizer
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    • v.46 no.3
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    • pp.209-215
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    • 2013
  • This study was conducted to investigate the effects of boron treatments on flower spike dieback of Statice (Limonium spp.) grown in soilless hydroponic and soil cultures under rain shelter system. The growth of Statice was gradually improved with increasing boron applications in the hydroponics, but not in soil culture with boron treatment as foliar spray or soil application. The degree of flower spike dieback in 6 levels (0, no dieback incidence to 5, very severe dieback incidence) ranged between 0.5 with boron application and 4.4 with no boron treatment. The content of boron in Statice flower spike increased with increasing rates of boron applications in the hydroponics, but the contents of P, Mg, and N were not affected by the boron application. However, K content was highest with no boron treatment. In soil culture, incidence of flower spike dieback decreased with foliar spray or soil application of boron. Therefore, boron application was effective in reducing flower spike dieback and improving cut-flower productivity and its quality, and the recommended rates of boron application were $50{\sim}80{\mu}gL^{-1}$ for hydroponics culture whereas 0.2% borex or ${\geq}0.4kg\;10a^{-1}$ boric acid by foliar spray application for soil culture.

Hybrid MAC Protocol Design for an Underwater Acoustic Network (수중음향통신망을 위한 하이브리드 MAC 프로토콜 설계)

  • Park, Jong-Won;Ko, Hak-Lim;Cho, A-Ra;Yun, Chang-Ho;Choi, Young-Chol;Lim, Yong-Kon
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.13 no.10
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    • pp.2088-2096
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    • 2009
  • This paper deals with hybrid MAC protocol design for underwater acoustic networks. The proposed MAC protocol has the cluster structure with a master node and slave nodes, and the hybrid network structure that combines a contention free period based on TDMA(Time Division Multiple Access) with a contention period. The suggested MAC protocol has a beacon packet for supervising network, a guard period between time slots for packet collision, time tag for estimation of propagation delay with a master node, the time synchronization of nodes, entering and leaving of network, and the communication method among nodes. In this paper, we adapt the proposed hybrid MAC protocol to AUV network, that is the representative mobile device of underwater acoustic network, and verify this protocol is applicable in real underwater acoustic network environment.