재조합효모를 이용한 배양 중 pH변화에 따른 인간 라이소자임의 대량생산

최선욱,이승철,황용일 慶南大學校 附設 基礎科學硏究所 1998 硏究論文集 Vol.12 No.-

Human lysozyme(HLT ; EC 3.4.1.17) is a cell wall lytic enzyme which consists of 130 amino acid residues. We have already prepared an artificial HLY gene from chemically synthesized 38-oligomer with high codon usage in S. cerevisiae. For directing the synthesis and secretion of HLY in S. cerevisiae, a YEp 2-㎛ circle-based vector, pHK501 was constructed by inserting the HLY gene. First, for HLY production during recombinant cell fermentations, compositions of culture mediums, pH, and glucose concentration were optimized. The various complex media containing yeast extract were used to increase the cell mass and HLY activity, but were not recommendable because of low plasmid stability during fermentations. Higher extracellular HLY activity was obtained in the synthetic medium containing 4% initial glucose. Higher HLY activity was observed when pH was controlled to 5.5 in comparison with pH-uncontrolled fermentations. Second, for enhancing the secretion of HLY in recombinant S. cerevisiae, a pH shift process was examined. After reaching stationary growth phase, extracellular HLY activity was significantly increased when pH in culture broth was purposely dropped to 3.0. This pH shift process seems to be very effective strategy for secretion of HLY in periplasmic space.

외과적 보조의 급속상악확장술 : 치험 5예 REPORT OF 5 CASES

박충열,이용욱,송종운,김영운,박홍주,오희균,유선열,이기현,황현식 대한악안면성형재건외과학회 2002 Maxillofacial Plastic Reconstructive Surgery Vol.24 No.1

Five adults (3 cases of bilateral posterior crossbite, 2 cases of unilateral posterior crossbite) with intermaxillary discrepancy of over 5㎜ due to maxillary transverse deficiency were treated by surgically assisted rapid maxillary expansion (SARME). Bilateral maxillary horizontal osteotomies, osteotomies of pterygomaxillary junction and anterior lateral nasal wall, ans anterior palatal osteotomy were performed in 4 cases, and unilateral osteotomies in 1case, followed by palatal expansion with tooth-borne orthopedic applicance. No significant complication was observed. The mean palatal expansion was 7.2㎜ (5.8∼10.0㎜) in the maxillary first molar region. During the mean follow-up period of 4 years (5 months∼8 years 7 months), no recurrence of crossbite was observed in all cases. The SARME seemed to be a simple, stable, and reliable procedure for achieving a permanent increase of over 5㎜ in skeletal maxillary transverse width of adults.

American Medical Association 5판을 근거로 한 한국형 말초신경계 장애 평가기준 개발

박동식,김병조,황선철,송인욱,손병철,장성호,정두신 순천향대학교 의학연구소 2009 Journal of Soonchunhyang Medical Science Vol.14 No.3

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Characterization of α-Gal Epitope in Cells and Tissues from Homozygous α-1,3-Galactosyltransferase Knockout Pigs

Hwang, In-Sul,Kwon, Dae-Jin,Kwak, Tae-Uk,Oh, Keon Bong,Ock, Sun-A,Chung, Hak-Jae,Im, Gi-Sun,Hwang, Seongsoo The Korean Society of Animal Reproduction 2015 Reproductive & developmental biology Vol.39 No.4

To overcome the hyperacute immune rejection during pig-to-non-human primates xenotranasplantation, we have produced and bred ${\alpha}$-1,3-galactosyltransferase knock-out ($GalT^{-/-}$) pigs. In this study, the somatic cells and tissues from the $GalT^{-/-}$ pigs were characterized by an analysis of the expression of Gal${\alpha}$-1,3-Gal (${\alpha}-Gal$) epitope. Briefly, ear fibroblast cell lines of 19 homozygous $GalT^{-/-}$ pigs were established and cryopreserved. The expression of ${\alpha}-Gal$ epitope in the cells was measured by fluorescence activated cell sorter (FACS) analysis using BS-I-B4 lectin. Also, the homozygous ($GalT^{-/-}$) cells and tissues samples were immunostained with BS-I-B4 lectin for analysis of ${\alpha}-Gal$ epitope expression. The results showed that the expression of ${\alpha}-Gal$ epitope in $GalT^{-/-}$ cells (0.2 %) were significantly (p<0.05) down-regulated to the range of cynomolgus monkey fibroblast (0.2 %) cells compared to heterozygous ($GalT^{-/+}$) (9.3 %) and wild type ($GalT^{+/+}$) (93.7 %) fibroblast cells. In the immunostaining results, while the expression of ${\alpha}-Gal$ epitope was detected a partly in $GalT^{-/+}$ cells and mostly in $GalT^{+/+}$ cells, it was almost not detected in the $GalT^{-/-}$ cells. Also, immunostaining results from various tissues of the $GalT^{-/-}$ pig showed that the expression of ${\alpha}-Gal$ epitope was not detectable, whereas various tissues from $GalT^{+/+}$ pig showed a strong expression of ${\alpha}-Gal$ epitope. Our results demonstrated that ${\alpha}-Gal$ epitope expressions from $GalT^{-/-}$ pigs were successfully knocked out to prevent hyperacute immune rejection for further study of xenotransplantation.

Effect of a short-term in vitro exposure time on the production of in vitro produced piglets

Hwang, In-Sul,Kwon, Dae-Jin,Kwak, Tae-Uk,Lee, Joo-Young,Hyung, Nam-Woong,Yang, Hyeon,Oh, Keon Bong,Ock, Sun-A,Park, Eung-Woo,Im, Gi-Sun,Hwang, Seongsoo The Korean Society of Embryo Transfer 2016 한국동물생명공학회지 Vol.31 No.2

Although piglets have been delivered by embryo transfer (ET) with in vitro produced (IVP) embryos and blastocysts, a success rate has still remained lower level. Unlike mouse, human, and bovine, it is difficult to a production of piglets by in vitro fertilization (IVF) because of an inappropriate in vitro culture (IVC) system in pig. Therefore, the present study was conducted to investigate whether minimized exposure time in IVC can improve the pregnancy and delivery rates of piglets. Immediately after IVM, the oocytes were denuded and co-incubated with freshly ejaculated boar semen for 3.5 to 4 hours at $38.5^{\circ}C$ under 5% $CO_2$ in air. To avoid long-term exposure to in vitro state, we emitted IVC step after IVF. After that the presumptive zygotes were transferred into both oviducts of the surrogate on the same day or 1 day after the onset of estrus. Pregnancy was diagnosed on day 28 after ET and then was checked regularly every month by ultrasound examination. The 3 out of 4 surrogates were determined as pregnant (75%) and a total of 5 piglets (2 females and 3 males) were delivered at $118.3{\pm}2.5$ days of pregnancy period. In conclusion, a short-term exposure time may be an important factor in the production of IVP-derived piglets. It can be apply to the in vitro production system of transgenic pig by IVF, cloning, and pronuclear microinjection methods.

Immersive Virtual Custom-made Model House

Sun-Uk Hwang(황선욱),Yeongmi Kim(김영미),Yongwon Seo(서용원),Kwang-Hee Ko(고광희),Jeha Ryu(류제하),Kwan Heng Lee(이관행),Yong-Gu Lee(이용구) (사)한국CDE학회 2008 한국CDE학회 논문집 Vol.13 No.1

Maximizing the Workspace of Optical Tweezers

Hwang, Sun-Uk,Lee, Yong-Gu Optical Society of Korea 2007 Current Optics and Photonics Vol.11 No.4

Scanning Laser Optical Tweezers(SLOT) is an optical instrument frequently employed on a microscope with laser being delivered through its various ports. In most SLOT systems, a mechanical tilt stage with a mirror on top is used to dynamically move the laser focal point in two-dimensions. The focal point acts as a tweezing spot, trapping nearby microscopic objects. By adding a mechanical translational stage with a lens, SLOT can be expanded to work in three-dimensions. When two mechanical stages operate together, the focal point can address a closed three-dimensional volume that we call a workspace. It would be advantageous to have a large workspace since it means one can trap and work on multiple objects without interruptions, such as translating the microscope stage. However, previous studies have paid less consideration of the volumetric size of the workspace. In this paper, we propose a new method for designing a SLOT such that its workspace is maximized through optimization. The proposed method utilizes a matrix based ray tracing method and genetic algorithm(GA). To demonstrate the performance of the proposed method, experimental results are shown.

Adaptive haptic rendering for time-varying haptic and video frame rates in multi-modal interactions

Hwang, Sun-Uk,Lee, Beom-Chan,Ryu, Jeha,Lee, Kwan H.,Lee, Yong-Gu John Wiley Sons, Ltd. 2010 Computer Animation and Virtual Worlds (Print) Vol.21 No.1

<P>In multi-modal interactions including haptics, problems such as input sensor noise, temporal mismatch between graphics and haptics, and non-constant refresh rates may cause non-smooth force/torque display. This paper proposes temporal smoothing technique for haptic interaction using a sensing glove in multi-modal applications. The proposed technique employs two processes: (1) a noise reduction method is applied to reduce jitter noise at the sensors in the sensing glove and (2) an adaptive force extrapolation is applied for time-varying haptic and video frame rates. To demonstrate the performance of the proposed method, we developed a test platform to assess a simple box model and relatively complex models such as gamephone, portable media player (PMP). It was subsequently demonstrated that the proposed method can support smooth haptic interactions in multi-modal applications where a haptic device and a sensing glove are used. Copyright © 2009 John Wiley & Sons, Ltd.</P> <B>Graphic Abstract</B> <P>This paper proposes a temporal smoothing technique for an interactive and smooth interaction using a haptic device and a sensing glove for multi-modal applications. The proposed technique employs a noise reduction method to reduce jitter noise in the sensing glove and an adaptive force extrapolation to alleviate the force discontinuity due to the time varying haptic and video frame rates. Through the exemplary applications and subjective user evaluation, the performance of proposed method was evaluated. <img src='wiley_img/15464261-2010-21-1-CAV328-gra001.gif' alt='wiley_img/15464261-2010-21-1-CAV328-gra001'> </P>

Peroxiredoxin I Is an Indicator of Microglia Activation and Protects against Hydrogen Peroxide-Mediated Microglial Death

Kim, Sun-Uk,Hwang, Chang Nam,Sun, Hu-Nan,Jin, Mei-Hua,Han, Ying-Hao,Lee, Hwang,Kim, Jin-Man,Kim, Sang-Keun,Yu, Dae-Yeul,Lee, Dong-Seok,Lee, Sang Ho Pharmaceutical Society of Japan 2008 Biological & pharmaceutical bulletin Vol.31 No.5

<P>Imbalance between oxidative stress and antioxidative defence system is generally known as one of mechanisms causing an oxidative stress-medieated neuropathogenesis. Peroxiredoxins (Prxs), a family of antioxidative enzymes neutralizing cellular hydroperoxides, was characterized recently, but their distributions and roles have not been resolved clearly or controversial in the central nervous system, Therefore, the present study was carried out to determine the specific cell types that express Prx I in the mouse brain and primary neural cells, and to examine its antioxidative role in the preferential cell types. Immunohistochemical reactivity for Prx I was detected dominantly in oligodendrocytes and rarely in microglia, whereas strong and specific immunoreactivity for Prx I was observed exclusively in microglia of primary neural cell culture. Further evidences for Prx I specificity were its relatively high expression in BV-2 microglial cells and its upregulated expression in microglia after lipopolysaccharide (LPS) stimulation. These results imply that Prx I can be used as an indicator of microglial activation. Inhibition of p38 MAPK ablated LPS-mediated Prx I upregulation and sensitized the microglia to H<SUB>2</SUB>O<SUB>2</SUB>-mediated cell death. These findings indicate that Prx I function as a scavenger for H<SUB>2</SUB>O<SUB>2</SUB> generated during microglial activation. The results of this study will help in unraveling the neuropathologic roles of the six Prx isoforms in neural function.</P>

이광자 중합 광조형을 이용한 마이크로 부품 성형을 위한 복셀 기반 레이저 초점 이동 경로 제어

황선욱(Sun-Uk Hwang),이용구(Yong-Gu Lee) (사)한국CDE학회 2010 한국 CAD/CAM 학회 학술발표회 논문집 Vol.2010 No.1

Two-photon photopolymerization via two-photon absorption is a promising three-dimensional microfabrication technique that has a considerable attraction. This method uses tightly focused ultra-short laser pulses to apply high energy in small volume of photo-sensitive polymer resin for subsequent photopolymerization. Because of nonlinear nature of this process, a resolution beyond diffraction limit can be realized by carefully controlling the laser pulse energy and exposure time. In this paper, we present the voxel based laser focal point positioning method for fabrication of micro-parts using two-photon photopolymerization. The proposed method can locate the laser focal point layer by layer using voxel position and exposure time can be controlled using gray level voxel value.