Publications by authors named "Taejin Kang"

The B subunit of Escherichia coli heat-labile toxin (LTB) is a model antigen that induces a strong immune response upon oral administration and enhances immune responses to conjugated and co-administered antigens. We previously examined high expression levels of LTB in plants by chloroplast and synthetic LTB gene expression and found substantially higher expression levels of LTB, compared to nuclear LTB expression in wild-type plants. The 2.

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Objectives: We proposed to investigate predictors of biochemical recurrence (BCR) in pT2 prostate cancer by identifying the interrelationship between the tumor volume and surgical margin status, and their impact on recurrence.

Materials And Methods: Clinical, pathologic, and follow-up data of 404 consecutive patients who were treated with radical prostatectomy alone and were diagnosed as pT2 prostate cancer in our institution were reviewed. Percent tumor volume (PTV) was estimated from the cancer distribution map, and the surgical margin status was reviewed by a single pathologist (JYR).

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Background: Components of metabolic syndrome have been associated with kidney stone disease, but little evidence is available to support a relationship between metabolic syndrome and kidney stone development in healthy large screened populations.

Study Design: Cross-sectional analysis.

Setting & Participants: Data were obtained from 34,895 individuals who underwent general health screening tests between January 2006 and December 2006 at the Asan Medical Center.

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Background: Early studies reported comparative results of functional outcomes between robot-assisted (RARP) and retropubic radical prostatectomy (RRP). However, well-controlled single-surgeon prospective studies comparing the outcomes are rare.

Objective: To compare functional outcomes after RARP and RRP performed by a single surgeon, and to identify factors predictive of early return of continence and potency.

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Type I IFNs were discovered as the primary antiviral cytokines and are now known to serve critical functions in host defense against bacterial pathogens. Accordingly, established mediators of IFN antiviral activity may mediate previously unrecognized antibacterial functions. RNase-L is the terminal component of an RNA decay pathway that is an important mediator of IFN-induced antiviral activity.

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The synthetic cholera toxin B subunit (CTB) gene, modified according to the optimized codon usage of plant genes, was introduced into a plant expression vector and expressed under the control of the Bx17 HMW (high molecular weight) wheat endosperm-specific promoter containing an intron of the rice act1. The recombinant vector was transformed into rice plants using a biolistic-mediated transformation method. Stable integration of the synthetic CTB gene into the chromosomal DNA was confirmed by PCR amplification analysis.

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CD1d-restricted invariant natural killer T cells (iNKT cells) have been identified as an important type of effector and regulatory T cell, but their roles in the chronic infectious diseases caused by Mycobacterium tuberculosis and Mycobacterium leprae remain poorly defined. Here, we studied circulating human iNKT cells in blood samples from tuberculosis (TB) and leprosy patients. We found that the percentages of iNKT cells among total circulating T cells in TB and leprosy patients were not significantly different from those in normal controls.

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Epitopes often require co-delivery with adjuvant and targeting proteins to enable recognition by the immune system, and this approach may also increase the efficacy of the antigen. In this study, we assess and describe the ability of transgenic rice plants to express a fusion protein consisting of the B-subunit of the Escherichia coli heat-labile enterotoxin (LTB) and a synthetic core-neutralizing epitope (COE) of porcine epidemic diarrhea virus (PEDV), inducing an enteric disease that is seen most predominantly in piglets. Both components of the fusion proteins were detected with Western blot analysis.

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Actinobacillus pleuropneumoniae is the causative agent of porcine pleuropneumonia. Among the virulence factors, ApxIIA, a bacterial exotoxin, is reportedly expressed in many serotypes and is considered as a candidate for the development of a vaccine against the bacterial infection. Previously, we isolated a field strain of A.

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Escherichia coli heat-labile enterotoxin B subunit (LTB) strongly induces immune responses and can be used as an adjuvant for co-administered antigens. Synthetic LTB (sLTB) based on optimal codon usage by plants was introduced into lettuce cells (Lactuca sativa) by Agrobacterium tumefaciens-mediated transformation methods. The sLTB gene was detected in the genomic DNA of transgenic lettuce leaf cells by PCR DNA amplification.

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A protocol has been developed to produce a cholera toxin B subunit (CTB) in tobacco tolerant to the herbicide phosphinothricin (PPT) by means of in vitro selection. The synthetic CTB subunit gene was altered to modify the codon usage to that of tobacco plant genes. The gene was then cloned into a plant expression vector and was under the control of the ubiquitin promoter and transformed into tobacco plants by Agrobacterium-mediated transformation.

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Purpose: We evaluated and compared the effects of different types of urinary diversion on functional and radiographic changes in the upper urinary tract.

Materials And Methods: We analyzed data on 275 patients who underwent radical cystectomy and urinary diversion for bladder cancer and were observed at least 12 months. Of the patients 197 received an orthotopic bladder substitute, including antirefluxing ureteral anastomoses in 111 (group 1) and refluxing ureteral anastomoses in 86 (group 2).

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The pentameric B subunit of Escherichia coli heat-labile enterotoxin (LTB) can be used as an efficient mucosal carrier of either immunogenic or tolerogenic T-cell epitopes. Co-delivery of therapeutic proteins with carrier proteins could increase the effectiveness of the antigen. This paper reports the ability of transgenic tobacco plants to express a fusion protein consisting of the synthetic LTB and a synthetic neutralizing epitope of porcine epidemic diarrhea virus (PEDV), causing an enteric disease that is especially severe in piglets.

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Article Synopsis
  • The B subunit of E. coli heat-labile toxin (LTB) is effective as a mucosal immunogen and works well as an adjuvant for vaccines.
  • Researchers cultivated transgenic somatic embryos of Siberian ginseng in a large bioreactor to produce LTB efficiently.
  • The process resulted in significant LTB production, confirmed by specific binding to GM1-ganglioside, indicating the formation of active pentamers for potential vaccine development.
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Porcine epidemic diarrhea virus (PEDV) causes acute diarrhea and dehydration in pigs and leads to death with a high mortality rate, which has been reported notably in Korea. The spike (S) gene of the PEDV isolated in Korea was cloned and sequenced. The nucleotide sequence encoding the entire S gene open reading frame of Korean strain was 4161 bases long encoding 1387 amino acids.

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We analyzed the prostate cancer data of 317 Korean men with clinically localized prostate cancer who underwent radical prostatectomy at Asan Medical Center between June 1990 and November 2003 to construct nomograms predicting the pathologic stage of these tumors, and compared the outcome with preexisting nomograms. Multinomial log-linear regression was performed for the simultaneous prediction of organ-confined disease (OCD), extracapsular extension (ECE), seminal vesicle invasion (SVI) and lymph node metastasis (LNM) using serum prostate-specific antigen (PSA), Gleason score and clinical stage. Nomograms representing percent probabilities were constructed and compared with those presented by Partin et al.

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Porcine epidemic diarrhea virus (PEDV) causes acute diarrhea and dehydration in pigs, leading to death with a high mortality. In this study, the synthetic neutralizing epitope gene of PEDV, which was optimized based on the coding sequence of tobacco plant genes being modified, was expressed in the no-nicotine tobacco plants. The synthetic gene was cloned into the plant expression vector under the control of CaMV 35S promoter and transformed by an Agrobacterium-mediated transformation.

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Porcine epidemic diarrhea virus (PEDV) causes acute enteritis in pigs of all ages and is often fatal for neonates. A tobacco mosaic virus (TMV)-based vector was utilized for the expression of a core neutralizing epitope of PEDV (COE) for the development of a plant-based vaccine. In this study, the coding sequence of a COE gene was optimized based on the modification of codon usage in tobacco plant genes and the removal of mRNA-destabilizing sequences.

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Chloroplast transformation systems offer unique advantages in biotechnology, including high level of foreign gene expression, maternal inheritance, and polycistronic expression. We studied chloroplast expression of LTK63 (change Ser-->Lys at position 63 in the A subunit) which is the mutant of Escherichia coli heat-labile toxin. LTK63 is devoid of any toxic activity, but still retains its mucosal adjuvanticity.

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Background: DNA extraction methods for PCR-quality DNA from calluses and plants are not time efficient, since they require that the tissues be ground in liquid nitrogen, followed by precipitation of the DNA pellet in ethanol, washing and drying the pellet, etc. The need for a rapid and simple procedure is urgent, especially when hundreds of samples need to be analyzed. Here, we describe a simple and efficient method of isolating high-quality genomic DNA for PCR amplification and enzyme digestion from calluses, various wild-type and transgenic plants.

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Escherichia coli heat-labile toxin (LT) is a potent mucosal immunogen and immunoadjuvant for coadministered antigens. We synthesized a gene encoding the B-subunit of LT (LTB) adapted to the coding sequence of tobacco plants and fused to the endoplasmic reticulum retention signal SEKDEL to enhance its level of expression in plants. The synthetic LTB gene was cloned into a plant expression vector adjacent to the CaMV 35S promoter and was introduced into tobacco by Agrobacterium-mediated transformation.

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RIPK 2 is adapter molecule in the signal pathway involved in Toll-like receptors. However, there has been no reported association between receptor-interacting serine/threonine kinase 2 (RIPK 2) expression and the infectious diseases involving mycobacterial infection. This study found that its expression was down-regulated in the footpads and skin but was up-regulated in the liver of Mycobacterium leprae-infected nu/nu mice compared with those of the M.

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Transgenic chloroplasts have become attractive systems for heterologous gene expressions because of unique advantages. Here, we report a feasibility study for producing the nontoxic B subunit of Escherichia coli heat-labile enterotoxin (LTB) via chloroplast transformation of tobacco. Stable site-specific integration of the LTB gene into chloroplast genome was confirmed by PCR and genomic Southern blot analysis in transformed plants.

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The effectiveness of different promoters for use in transgenic tobacco was compared using a reporter gene expressing chloramphenicol acetyl transferase (CAT). Plasmids with CAT gene controlled by cauliflower mosaic virus 35S (CaMV 35S), rice actin1 (Ract1) and tobacco polyubiquitin (Tubi.u4) promoters were delivered into tobacco plants by Agrobacterium-mediated transformation.

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The chloroplast transformation system has the potential advantages of maternal inheritance and high-level expression of heterologous genes. We studied the expression of the bar gene in tobacco chloroplasts to test these ideas. The bar gene conferring tolerance to the herbicide phosphinothricin (PPT) encodes phosphinothricin acetyltransferase (PAT).

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