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Choi, Min-Sue,Yoon, In-Sun,Rhee, Yong,Choi, Seung-Kook,Lim, Sun-Hyung,Won, So-Youn,Lee, Yeon-Hee,Choi, Hong-Soo,Lee, Suk-Chan,Kim, Kook-Hyung,Lomonossoff, George,Sohn, Seong-Han The Korean Society of Plant Pathology 2008 Plant Pathology Journal Vol.24 No.3
The transient and rapid expression system of a foreign protein in planta is a very useful technique in biotechnology application. We have investigated optimum condition of Agrobacterium-infiltration technique in which expression level of foreign proteins were maximized without detrimental effects on plants using GFP and Cucumber mosaic virus 2b protein, which is known as an enhancer of gene expression and a suppressor of post-transcriptional gene silencing(PTGS). The optimum expression level of both RNA and protein of GFP with minimum leaf impairment was obtained at $OD_{600}$=0.2 of Agrobactrium inocula. The steady-state levels of GFP RNA and protein generally peaked at 3 and 7 days post-infiltration(dpi), respectively. In the presence of 2b, both the magnitude and duration of GFP expression was highly increased and we could detect GFP level until 17 dpi. On the other hands, the 2b-mediated higher accumulation of foreign proteins resulted in the repression of normal leaf growth, possibly due to the limitation of supply of energy or materials required for growth maintenance. Using this Agrobacterium-infiltration system with 2b and GFP, we tested a hypothesis for the threshold model of PTGS initiation. Four GFP transgenic lines of N. benthamiana, which shows different expression level of GFP were tested to determine the threshold level for PTGS initiation. Agrobacterium-infiltration of GFP into those GFP-transgenic plants resulted in the co-silencing of the transgenic GFP. It was found that very low concentration of Agrobacterium with GFP and GFP+2b($OD_{600}$=0.002-0.02) which could not phenotypically induce an additive GFP expression, was enough to trigger PTGS pathway in all GFP transgenic plants. This strongly indicates that each GFP-transgenic plant should be expressing the transgenic GFP at its own pre-determined level and there was no buffer zone of additive GFP-expression to the threshold. In other words, the PTGS seems to be immediately activated as a self-defensive mechanism if an internal balance of gene expression is broken.
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Effect of αGal on corneal xenotransplantation in a mouse model
Choi, Hyuk Jin,Kim, Mee Kum,Lee, Hyun Ju,Jeong, So Hee,Kang, Hee Jung,Park, Chan‐,Sik,Park, Chung‐,Gyu,Joon Kim, Sang,Wee, Won Ryang Blackwell Publishing Ltd 2011 Xenotransplantation Vol.18 No.3
<P>Choi HJ, Kim MK, Lee HJ, Jeong SH, Kang HJ, Park C‐S, Park C‐G, Kim SJ, Wee WR. Effect of αGal on corneal xenotransplantation in a mouse model. Xenotransplantation 2011; 18: 176–182. © 2011 John Wiley & Sons A/S.</P><P><B>Abstract: </B><B> Background: </B> It has been reported that hyperacute rejection (HAR) does not occur after pig‐to‐nonhuman corneal xenotransplantation. However, considering that immune privilege is already disrupted in most human corneal recipients, and the expression of αGal can be gradually reduced after pig‐to‐rat corneal transplantation, the long‐term survival of corneal grafts from wild‐type pigs cannot be guaranteed. Accordingly, we aimed to investigate the effect of αGal on the change in anti‐Gal antibodies, using sensitized α1,3‐galactosyltransferase gene‐knockout (GTKO) mice recipients.</P><P><B>Methods: </B> C57BL/6 (B6) and GTKO mice were divided into 5 groups and underwent orthotopically full thickness cormeal transplantation as follows (n=4 for each group): (1) group 1: B6 to B6; (2) group 2: fresh porcine posterior corneal lamella to B6; (3) fresh porcine posterior corneal lamella to GTKO; (4) group 4: decellularized porcine posterior corneal lamella to GTKO, and (5) group 5: B6 to GTKO. Before transplantation, all GTKO recipients were sensitized using intraperitoneal injections of rabbit blood cells. Median survival times (MST) for the corneal grafts of the different groups were compared and plasma concentrations of IgG/IgM anti‐Gal antibodies were evaluated at 1 week, 2 weeks and 3 weeks post‐transplantation.</P><P><B>Results: </B> There were no differences in MSTs between groups. Although there was no HAR of fresh porcine posterior corneal grafts even in sensitized GTKO recipients, αGal expression was induced in the transplanted fresh porcine corneal grafts and plasma concentration of IgG anti‐Gal antibody was gradually increased in fresh porcine cornea‐grafted GTKO recipients. On the contrary, αGal expression did not increase in the grafts and plasma concentration of anti‐Gal antibodies did not change after transplantation using decellularized porcine corneas.</P><P><B>Conclusions: </B> Our findings suggest that αGal may affect the long‐term survival of porcine corneal xenografts via antibody‐mediated rejection, although αGal does not have an effect on acute rejection and decellularized porcine corneas may enable the long‐term survival of porcine corneal xenografts.</P>
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Choi, Hye-Ryung,Shin, Jung-Won,Na, Jung-Im,Nam, Kyung-Mi,Lee, Hyun-Sun,Park, Kyoung-Chan Hindawi Publishing Corporation 2015 Oxidative medicine and cellular longevity Vol.2015 No.-
<P>We found that tripeptide “ACQ: alanine-cysteine-glutamine” has significant DPPH scavenging activity compared to that of glutathione. Antioxidant effects of ACQ were tested in <I>in vitro</I> and <I>in vivo</I> models. When treated with H<SUB>2</SUB>O<SUB>2</SUB>, mock treated fibroblasts and keratinocytes showed strong staining by H<SUB>2</SUB>DCFA. But, ACQ showed good protective effects against hydrogen peroxide treatment. When mice were fed for 2 or 4 weeks, similar protective effects were observed. In the control group, epidermis was severely damaged by UV irradiation and apoptotic keratinocytes were observed. There were also numerous TUNEL positive cells. But in the ACQ group, epidermis became thicker and there was no sign of severe damage. Interestingly, the number of p63 cells was also higher in ACQ fed mice. To confirm the stem cell rescuing effects of ACQ, three-dimensional skin samples were constructed. Results showed that ACQ increased the expression of integrin <I>α</I>6 and the number of p63 positive cells. These findings showed that ACQ has good antioxidant activity and may increase stem cell activities by the regulation of integrin <I>α</I>6.</P>
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( Chan Ran You ),( Su Hyung Park ),( Sung Won Jeong ),( Hyun Young Woo ),( Si Hyun Bae ),( Jong Young Choi ),( Young Chul Sung ),( Seung Kew Yoon ) 대한간학회 2011 Gut and Liver Vol.5 No.4
Background/Aims: Interferon-γ-inducible protein 10 (IP-10) plays important roles in the pathogenesis of hepatitis C virus (HCV) infection. We investigated the association between serum IP-10 levels and liver pathology in patients with chronic HCV infection. Methods: The serum IP-10 concentration was assessed in 85 patients with chronic HCV infection using a solid phase sandwich enzyme-linked immunosorbent assay, and a liver biopsy specimen was obtained. The pathology was scored using the Knodell histologic activity index (HAI). Results: Of the 85 patients, 58 had genotype 1 HCV infection, 21 had genotype non-1, and 6 were undetermined. The serum IP-10 levels did not differ between patients infected with genotype 1 and genotype non-1 (p=0.472). In patients with genotype 1 infection, the total HAI score and the stage of fi brosis were highly correlated with the serum IP-10 level (r=0.555, r=0.578, p<0.001). Furthermore, the serum IP-10 concentrations of patients with severe fi brosis (stages 3, 4) were higher than those of patients with mild fi brosis (stages 0 to 2; 214.4 vs. 72.3 pg/mL, p=0.002) among patients with genotype 1 infection. However, in patients without genotype 1 infection, the histopathology was not associated with the serum IP-10 level. A multivariate analysis showed that serum IP-10 was an independent predictor of fi brosis (stages 3, 4) in patients with genotype 1 infection (odds ratio, 1.034; 95% confi dence interval, 1.006 to 1.064; p=0.018). Conclusions: Serum IP-10 concentration was signifi cantly correlated with the severity of liver histology in genotype 1 HCV infection. (Gut Liver 2011;5:506-512)
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( Won Oh Kim ),( Han Byul Kim ),( Eu Gene Han ),( Nan Hee Cho ),( Mi Sun Choi ),( Ho Chan Cho ),( Sung Ae Kim ) 대한피부과학회 2018 대한피부과학회 학술발표대회집 Vol.70 No.2
Background: With the increase in the prevalence of diabetic foot ulcer (DFU), the demand for optimal treatment and management strategies has risen too. Objectives: Our study investigated the wound-healing effect of platelet-rich plasma (PRP) on DFU and the correlations between the various factors affecting DFU treatment. Methods: 10 diabetes patients with grade 1 DFU were treated using PRP prepared from the patients’ blood (collected using a commercial kit, MyCells Autologous Preparation kit<sup>®</sup>, Holon, Israel). The ulcer margins were biopsied before and after PRP treatment. Hematoxylin and Eosin staining and immunohistochemical staining for HIF-1α and CD31 were performed to confirm angiogenesis. Spearman’s correlation tests were performed to determine the correlations between the treatment period and various clinical factors. Results: The mean PRP treatment period was 29.4 days. PRP was administered a mean of 3 (1-6) times. The time taken for a 50% reduction in the wound area was 16 days. Among the clinical factors, the presence of calluses in the lesion prolonged the pretreatment period, and significantly reduced the duration of PRP treatment. After PRP treatment, on CD31 staining, the number of endothelial cells was significantly increased. However, on HIF-1α, there was no significant difference. Conclusion: We found that PRP can contribute to wound regeneration through neovascularization. PRP therapy, with various growth factors, is expected to be another treatment option for DFUs.
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Choi, Ji Na,Choi, Yun-Hyeok,Lee, Jeong-Min,Noh, Ill Chan,Park, Jae Won,Choi, Wahn Soo,Choi, Jung Ho Taylor Francis Health Sciences 2012 NATURAL PRODUCT RESEARCH Vol.26 No.24
<P>Trachelospermum jasminoides (Apocynaceae) has pharmacological effects that include anti-inflammatory, anti-bacterial and anti-viral activities, which have been observed from various studies. Of these pharmacological effects, the anti-inflammatory capacity of compounds from T. jasminoides is not yet known exactly. In this study, we investigated the compound that can be used for the suppression of lipopolysacchaide (LPS) stimulated inflammatory responses in macrophages among the five isolated compounds. β-sitosterol-β-D-glucoside (1) was found to reduce nitric oxide (NO) production from LPS-induced RAW 264.7 cells the most. In addition, compound 1 strongly inhibited the interleukin 6 (IL-6) activities of stimulated macrophages. Treatment of RAW 264.7 cells with compound 1 reduced secretion of inflammatory elements including tumour necrosis factor - alpha (TNF-α) and interleukin 1 beta (IL-1β). Thus, compound 1 may be a useful candidate for the development of new drugs to treat endotoxemia and inflammation accompanied by the overproduction of NO.</P>
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Butyltin Compounds Concentrations in Masan Bay
Choi, Hee Gu,Kim, Pyoung Joong,Lee, Won Chan 한국수산학회 1997 한국수산과학회지 Vol.30 No.6
The occurrence of butyltin compounds in the seawater and sediment of Masan Bay was investigated. The concentrations were in the range of ND-0.059㎍/ℓ for tributyltin(TBT), ND-0.091㎍/ℓ for dibutyltin(DBT) and ND-0.720㎍/ℓ for monobutyltin(MBT) in the seawater, and ND-0.233㎍ TBT/g.dry, ND-0.197㎍ DBT/g.dry and ND-0.684㎍ MBT/g.dry in the sediment. Among the butyltin compounds, the major component in the seawater was MBT, while the predominant species in the sediment changed with time. The tributyltin concentrations in the sediment are approximately three orders of magnitude greater than the associated water column levels. Sediment/water partition coefficients(K) of TBT were between 0.6×10³ and 5.0×10³.
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Chan Woo Cho,Gyu-Seong Choi,Jong Man Kim,Choon Hyuck David Kwon,Doo Jin Kim,Jae-Won Joh 대한외과학회 2018 Annals of Surgical Treatment and Research(ASRT) Vol.95 No.2
Purpose: Response to preoperative transarterial chemoembolization (TACE) has been recommended as a biological selection criterion for liver transplantation (LT). The aim of our study was to identify optimal timing of living donor liver transplantation (LDLT) after TACE based on the TACE response. Methods: We performed a retrospective study to assess recurrence in 128 hepatocellular carcinoma (HCC) patients who underwent LDLT following sequential TACE from January 2002 to March 2015 at a single institute. Cox proportional hazard models and Kaplan-Meier analysis were utilized to estimate HCC recurrence and find optimal timing for LDLT. Results: Seventy-three and 61 patients were divided as the responder and nonresponder, respectively. Multivariate analysis showed independent pre-liver transplantation (pre-LT) predictors of recurrence were larger sized tumor (>3 cm, P = 0.024), nonresponse to TACE (P = 0.031), vascular invasion (P = 0.002), and extrahepatic nodal involvement (P = 0.001). In the 3-month time difference between last pre-LT TACE and LDLT subgroup, TACE responders showed significantly higher adjusted hazard ratio (aHR) of recurrence free survival (aHR, 6.284; P = 0.007), cancer specific survival (aHR, 7.033; P = 0.016), and overall survival (aHR, 7.055; P = 0.005). Moreover, for overall patients and responder groups, the significant time difference between last pre-LT TACE and LDLT was 2 months in the minimum P-value approach. Conclusion: In selected patients who showed good response to pre-LT TACE, a shorter time interval between TACE and LDLT may be associated with higher recurrence free survival, cancer specific survival, and overall survival.
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