Subretinal transplantation of putative retinal pigment epithelial cells derived from human embryonic stem cells in rat retinal degeneration model

Park, Un-Chul,Cho, Myung-Soo,Park, Jung-Hyun,Kim, Sang-Jin,Ku, Seung-Yup,Choi, Young-Min,Moon, Shin-Yong,Yu, Hyeong-Gon The Korean Society for Reproductive Medicine 2011 Clinical and Experimental Reproductive Medicine Vol.38 No.4

Objective: To differentiate the human embryonic stem cells (hESCs) into the retinal pigment epithelium (RPE) in the defined culture condition and determine its therapeutic potential for the treatment of retinal degenerative diseases. Methods: The embryoid bodies were formed from hESCs and attached on the matrigel coated culture dishes. The neural structures consisting neural precursors were selected and expanded to form rosette structures. The mechanically isolated neural rosettes were differentiated into pigmented cells in the media comprised of N2 and B27. Expression profiles of markers related to RPE development were analyzed by reverse transcription-polymerase chain reaction and immunostaining. Dissociated putative RPE cells ($10^5$ cells/5 ${\mu}L$) were transplanted into the subretinal space of rat retinal degeneration model induced by intravenous sodium iodate injection. Animals were sacrificed at 1, 2, and 4 weeks after transplantation, and immnohistochemistry study was performed to verify the survival of the transplanted cells. Results: The putative RPE cells derived from hESC showed characteristics of the human RPE cells morphologically and expressed molecular markers and associated with RPE fate. Grafted RPE cells were found to survive in the subretinal space up to 4 weeks after transplantation, and the expression of RPE markers was confirmed with immunohistochemistry. Conclusion: Transplanted RPE cells derived from hESC in the defined culture condition successfully survived and migrated within subretinal space of rat retinal degeneration model. These results support the feasibility of the hESC derived RPE cells for cell-based therapies for retinal degenerative disease.

Enhanced accumulation of carotenoids in sweetpotato plants overexpressing <i>IbOr-Ins</i> gene in purple-fleshed sweetpotato cultivar

Park, Sung-Chul,Kim, Sun Ha,Park, Seyeon,Lee, Hyeong-Un,Lee, Joon Seol,Park, Woo Sung,Ahn, Mi-Jeong,Kim, Yun-Hee,Jeong, Jae Cheol,Lee, Haeng-Soon,Kwak, Sang-Soo Elsevier 2015 Vol. No.

<P><B>Abstract</B></P> <P>Sweetpotato [<I>Ipomoea batatas</I> (L.) Lam] is an important root crop that produces low molecular weight antioxidants such as carotenoids and anthocyanin. The sweetpotato orange (IbOr) protein is involved in the accumulation of carotenoids. To increase the levels of carotenoids in the storage roots of sweetpotato, we generated transgenic sweetpotato plants overexpressing <I>IbOr-Ins</I> under the control of the cauliflower mosaic virus (<I>CaMV) 35S</I> promoter in an anthocyanin-rich purple-fleshed cultivar (referred to as <I>IbOr</I> plants). <I>IbOr</I> plants exhibited increased carotenoid levels (up to 7-fold) in their storage roots compared to wild type (WT) plants, as revealed by HPLC analysis. The carotenoid contents of <I>IbOr</I> plants were positively correlated with <I>IbOr</I> transcript levels. The levels of zeaxanthin were ∼12 times elevated in <I>IbOr</I> plants, whereas β-carotene increased ∼1.75 times higher than those of WT. Quantitative RT-PCR analysis revealed that most carotenoid biosynthetic pathway genes were up-regulated in the <I>IbOr</I> plants, including <I>PDS</I>, <I>ZDS</I>, <I>LCY-β</I>, <I>CHY-β</I>, <I>ZEP</I> and <I>Pftf</I>, whereas <I>LCY-ɛ</I> was down-regulated. Interestingly, <I>CCD1</I>, <I>CCD4</I> and <I>NCED,</I> which are related to the degradation of carotenoids, were also up-regulated in the <I>IbOr</I> plants. Anthocyanin contents and transcription levels of associated biosynthetic genes seemed to be altered in the <I>IbOr</I> plants. The yields of storage roots and aerial parts of <I>IbOr</I> plants and WT plants were not significantly different under field cultivation. Taken together, these results indicate that overexpression of <I>IbOr-Ins</I> can increase the carotenoid contents of sweetpotato storage roots.</P> <P><B>Highlights</B></P> <P> <UL> <LI> <I>IbOr-Ins</I> gene was transferred into purple-fleshed sweetpotato. </LI> <LI> Overexpression of <I>IbOr-Ins</I> increased carotenoid contents in storage roots. </LI> <LI> Most carotenoid biosynthetic pathway genes were up-regulated in transgenic plants. </LI> <LI> <I>CCD</I> genes were differentially induced in <I>IbOr</I> transgenic plants. </LI> </UL> </P>

Effects of bisphenol A and its analogs bisphenol F and S on life parameters, antioxidant system, and response of defensome in the marine rotifer <i>Brachionus koreanus</i>

Park, Jun Chul,Lee, Min-Chul,Yoon, Deok-Seo,Han, Jeonghoon,Kim, Moonkoo,Hwang, Un-Ki,Jung, Jee-Hyun,Lee, Jae-Seong Elsevier 2018 Aquatic toxicology Vol.199 No.-

<P><B>Abstracts</B></P> <P>To understand the adverse outcome in response to bisphenol A and its analogs bisphenol F and S (BPA, BPF, and BPS), we examined acute toxicity, life parameter, and defensome in the marine rotifer <I>Brachionus koreanus</I>. Among the bisphenol analogs, BPA showed the highest acute toxicity and then BPF and BPS, accordingly in the view of descending magnitude of toxicity. In life parameters including life span and reproduction, BPA, BPF, and BPS were found to cause adverse effect. Both intracellular ROS level and GST activity were significantly increased (<I>P <</I> 0.05) in response to each dosage of bisphenol analogs exposures. In response to bisphenol analogs, defensomes of phase I, II, and III detoxification mechanism demonstrated inverse relationship between the lipophilicity of bisphenol analogs and the expression patterns of defensomes. BPA and BPF were found to have significant modulation (<I>P <</I> 0.05) in the expression of cytochrome P450 (<I>CYP</I>) and <I>GST</I> genes. In phase III, BPS with comparatively lower lipophilicity demonstrated highly diversified expressional pattern, suggesting that BPS is likely caused less toxicity compared to BPA and BPF. In this study, via phase I, II, and III detoxification mechanism, bisphenol A and its analogs F and S demonstrated specific detoxification mechanism in rotifer.</P> <P><B>Highlights</B></P> <P> <UL> <LI> BPA showed the highest acute toxicity and then BPF and BPS. </LI> <LI> BPA, BPF, and BPS were found to cause adverse effect in life parameters. </LI> <LI> Both intracellular ROS level and GST activity were significantly increased upon bisphenol analogs exposure. </LI> <LI> Expression of defensomes showed inverse relationship between the lipophilicity of bisphenol analogs in response to bisphenol analogs. </LI> <LI> BPA and BPF were found to have significant modulation in the expression of CYP and GST genes. </LI> </UL> </P>

Determination of Pentapeptide Repeat Units in Qnr Proteins by the Structure-Based Alignment Approach

Park, Kwang Seung,Lee, Jung Hun,Jeong, Da Un,Lee, Jae Jin,Wu, Xing,Jeong, Byeong Chul,Kang, Choong-Min,Lee, Sang Hee American Society for Microbiology 2011 Antimicrobial agents and chemotherapy Vol.55 No.9

<B>ABSTRACT</B><P>The Qnr proteins belong to the pentapeptide repeat protein family. Despite each pentapeptide repeat unit being an important structural determinant, accurately determining pentapeptide repeat units in the Qnr proteins through sequence-based alignments has been challenging. In the present study, the pentapeptide repeat units of the nine representative Qnr proteins have been precisely determined via the structure-based alignment approach using homology modeling and superposition of their best models.</P>

Adverse effects of two pharmaceuticals acetaminophen and oxytetracycline on life cycle parameters, oxidative stress, and defensome system in the marine rotifer <i>Brachionus rotundiformis</i>

Park, Jun Chul,Yoon, Deok-Seo,Byeon, Eunjin,Seo, Jung Soo,Hwang, Un-Ki,Han, Jeonghoon,Lee, Jae-Seong Elsevier 2018 Aquatic toxicology Vol.204 No.-

<P><B>Abstract</B></P> <P>To investigate the adverse effect of two widely used pharmaceuticals, paracetamol (acetaminophen [APAP]) and oxytetracycline (OTC) on the marine rotifer <I>Brachionus rotundiformis</I> (<I>B. rotundiformis</I>), the animals were exposed to various environmentally-relevant concentrations. Up to date, acetaminophen and oxytetracycline have been considered as toxic, if used above threshold concentration, <I>i.e.</I> overdosed. However, this study demonstrated these two pharmaceuticals even at low concentration (<I>i.e.</I>, μg/L scale) elicited oxidative stress through the generation of reactive oxygen species (ROS) along with the increased glutathione <I>S</I>-transferase activity, despite no-observed effect in <I>in-vivo</I> population growth. To validate the adverse effects of the two pharmaceuticals at relatively low concentrations, mRNA expression analysis was performed of the entire set of genes encoding 26 cytochrome P450s (CYPs) of phase I and 19 glutathione <I>S</I>-transferases (GSTs) of phase II of the rotifer <I>B</I>. <I>rotundiformis</I>. The mRNA expression analysis suggested specific genes <I>CYP3045A2</I> and <I>GSTσ1</I>, <I>GSTσ4</I>, and <I>GSTω1</I> take part in detoxification of APAP and OTC, resulting in no significant changes in the population growth and undetermined no observed effect concentration (NOEC) in the marine rotifer <I>B. rotundiformis</I>.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Low concentrations of two pharmaceuticals APAP and OTC elicited oxidative stress through the generation of ROS.. </LI> <LI> Low concentrations of two pharmaceuticals APAP and OTC increased glutathione S-transferase activity. </LI> <LI> APAP and OTC have no-observed effect in in-vivo population growth. </LI> <LI> <I>CYP3045A2</I> and <I>GSTs1</I>, <I>GSTs4</I>, and <I>GSTo1</I> were responsible in detoxification of APAP and OTC. </LI> <LI> These led no significant changes in the population growth and undetermined NOEC in rotifer. </LI> </UL> </P>

Identification of the Lactic Acid Bacteria in Kimchi According to Initial and Over-ripened Fermentation Using PCR and 16S rRNA Gene Sequence Analysis

Park, Jung-Min,Shin, Jin-Ho,Lee, Dan-Won,Song, Jae-Chul,Suh, Hyung-Joo,Chang, Un-Jae,Kim, Jin-Man 한국식품과학회 2010 Food Science and Biotechnology Vol.19 No.2

This paper aimed to identify the lactic acid bacteria species involved in kimchi fermentation at different fermentation periods by using culture-independent 16S rRNA gene clone libraries, and develop polymerase chain reaction for the detection of lactic acid bacteria (LAB). We investigated 6 commercially produced kimchi samples, including kimchi at an initial stage of fermentation and kimchi that was fermented to an over-ripened stage. The results of our study show that the analysis with culture-independent 16S rRNA gene clone libraries could successfully identify 134 clones, 11 species, including Weissella, Lactobacillus, Pediococcus, and Leuconostoc from the 6 commercial kimchi samples. Weisella koreensis and Lactobacillus brevis were the predominant LAB in the initial stage of kimchi fermentation at $4^{\circ}C$ (pH 4.96-5.27 and acidity 0.81-0.88), and Leuconostoc gelidum and Lactobacillus sakei subsp. sakei may play an important role in kimchi fermentation at the over-ripened stage (pH 3.61-3.91 and acidity 1.70-1.79).

Ahmed Glaucoma Valve Implantation for Neovascular Glaucoma After Vitrectomy for Proliferative Diabetic Retinopathy

Park, Un Chul,Park, Ki Ho,Kim, Dong Myung,Yu, Hyeong Gon Lippincott Williams Wilkins, Inc. 2011 Journal of glaucoma Vol.20 No.7

PURPOSE: To evaluate the safety and efficacy of Ahmed Glaucoma Valve implantation (AGVI) for the management of neovascular glaucoma (NVG) associated with proliferative diabetic retinopathy (PDR) in the vitrectomized eyes. PATIENTS AND METHODS: We reviewed the medical records of patients with NVG associated with PDR who underwent AGVI for intraocular pressure (IOP) control and compared the surgical outcome according to vitrectomy history. The main outcome measures were: postoperative IOP control, visual acuity, and complications. Success was defined as an IOP of ≤21 mm Hg and ≥6 mm Hg, without further glaucoma surgery or loss of light perception and devastating complications. RESULTS: A total of 73 patients (73 eyes) were included: 42 patients with vitrectomy history before AGVI (vitrectomized group) and 31 patients without vitrectomy history (nonvitrectomized group). The cumulative probabilities of success after AGVI were 89.9% and 83.8% after 1 year, 74.8% and 74.7% after 2 years, and 62.5% and 68.5% after 3 years for the vitrectomized group and the nonvitrectomized group, respectively (P=0.9309). Cox proportional hazards regression showed the intraocular silicone oil tamponade as a risk factor for the surgical failure (odds ratio=4.543, P=0.047). Final visual acuity improved or stabilized in 33 patients (78.6%) in the vitrectomized group and 18 patients (58.1%) in the nonvitrectomized group. Complications were comparable between the groups, but surgical interventions were needed for 5 patients (11.9%) in the vitrectomized group. CONCLUSION: Despite some complications that necessitate surgical intervention, the AGVI is a safe and effective procedure that enables successful IOP control and vision preservation in patients with NVG associated with vitrectomy for the PDR.

E-mail Classification and Category Re-organization using Dynamic Category Hierarchy and PCA

Park, Sun,Kim, Chul-Won,An, Dong-Un The Korea Institute of Information and Commucation 2009 Journal of information and communication convergen Vol.7 No.3

The amount of incoming e-mails is increasing rapidly due to the wide usage of Internet. We often group e-mails into categories for maintaining e-mail efficiently. However reading the email messages and classifying them is still tedious task. Moreover, the number of e-mails and manual classifying is increasing everyday. So, automatic e-mail classification is important techniques. In this paper, we propose a multi-way e-mail classification method that uses PCA for automatic category generation and dynamic category hierarchy for re-organizing e-mail categories. It classifies a huge amount of receiving e-mail messages automatically, efficiently, and accurately.

Polymerase Chain Reaction and Heteroduplex Analysis Based Detection of Clonal T Cell Receptor Gamma Gene Rearrangements in Paraffin - embedded Tissues of Cutaneous T Cell Proliferative Diseases

Park, Kyung Ho,Cho, Kwang Hyun,Kim, Chul Woo,Han, Kwang Ho,Ko, Young Hyeh,Yeo, Un Cheol,Lee, Eil Soo 대한피부과학회 2001 Annals of Dermatology Vol.13 No.3

Background : Recently, the molecular pathologic investigation for clonality in lymphomas has been introduced and has gained a role in the diagnosis of lymphomas. In fact, the clonality test using TCRGR phenomenon has been done by Southern blot analysis (SBA) and polymerase chain reaction (PCR) for molecular pathologic diagnosis of T cell lymphomas. However, it is difficult to perform SBA with paraffin embedded specimens or with samples of small skin biopsies. Objective : We investigated the efficacy of PCR amplification of TCR gene in paraffin embedded cutaneous T cell lymphomas. Methods : In this study, the clonality was assessed by polymerase chain reaction (PCR) analysis of T cell receptor gamma (TCR) gene from the DNA extracts obtained from paraffin embedded tissues (PET) of malignant T cells, B cell lymphomas, and benign cutaneous T cell proliferative disorders. Heteroduplex analyses were also performed to rule out the false positives. Results : Among the total of 62 cases analyzed, monoclonality was observed in 4 out of 10 mycosis fungoides, 7 out of 9 cutaneous T cell lymphomas excluding mycosis fungoides, 1 out of 3 angiocentric lymphomas, 2 out of 2 lymphomatosis papulosis, 1 out of 7 large plaque parapsoriasis, and 1 out of 2 T cell lymphomas in other organs. No monoclonality was observed in 9 inflammatory cutaneous diseases, 5 small plaque parapsoriasis, 4 cutaneous B cell lymphomas, and 11 B cell lymphomas in lymph nodes. Conclusion : The results suggest that the PCR method and heteroduplex analysis used in this study were not only practical but also efficacious for the diagnosis of cutaneous T cell lymphomas using tissues embedded in paraffins.

Development of Pressure Drop Model for the Compartment in Reactor Containment

Park, Cheol,Song, In-ho,Lee, Un-Chul Korean Nuclear Society 1986 Nuclear Engineering and Technology Vol.18 No.3

실제 발전소규모의 HDR 격납용기 실험에서 기존의 격납용기 해석모델에 많은 문제점들이 있다는 것이 밝혀졌는데, 그 중의 하나가 단기 (0∼2초) 압력 차이 계산이다. 격납용기의 각 구분방 사이의 압력차이는 질량 흐름율, 유체밀도, 마찰상실계수, 흐름면적비 등에 의존하는데, 각 요소가 압력 차이의 실험값과 계산값의 불일치에 어느 정도의 영향을 주는가는 정확하게 알려져 있지 않다 본 연구에서는 기존의 해석모델을 개선하기 위해 지금까지 상수로 간주되어 온 마찰상실계수를 압력과 압력차이 등의 함수로 제시되었다. COMPARE 코드로 수정된 모델을 사용하여 HDR 실험에 대한 압력과 압력차이가 계산되었는데 V.42 실험값에서는 측정치와 잘 맞고, V.43의 측정치 보다는 높게, V.44 실험값보다는 조금 낮은 결과를 보였다.