• Biotechnology and Bioprocess Engineering:BBE
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• v.5 no.6
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• pp.413-417
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• 2000

In this study, a direct detection system for triazine derivative herbicides was developed using the photosynthetic reaction center (RC) from the purple bacterium, Rhodobacter sphaeroides, and surface plasmon resonance (SPR) apparatus. The histidine-tagged RCs were immobilized on an SPR gold chip using nickel-nitrilotriacetic acid groups as a binder for one of the triazine herbicide, atrazine. The SPR responses were proportional to the sample concentrations of atrazine in the range 0.1-1 $\mu\textrm{g}$/mL. The sensitivity of the direct detection of atrazine using the RC-assembled sensor chip was higher than that using the antibody-immobilized chip. The other types of herbicides, DCMU or MCPP, were not detected with such high sensitivity. The results indicated the high binding selectivity of the RC complex.

• Journal of Ginseng Research
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• v.37 no.3
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• pp.300-307
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• 2013

20S-dihydroprotopanaxatriol (2H-PPT) is a derivative of protopanaxatrol from ginseng. Unlike other components from Panax ginseng, the pharmacological activity of this compound has not been fully elucidated. In this study, we investigated the modulatory activity of 2H-PPT on the cellular responses of monocytes and macrophages to understand its immunoregulatory actions. 2H-PPT strongly upregulated the release of radicals in sodium nitroprusside-treated RAW264.7 cells and the surface levels of costimulatory molecule CD86. More importantly, this compound remarkably suppressed nitric oxide production, morphological changes, phagocytic uptake, cell-cell aggregation, and cell-matrix adhesion in RAW264.7 and U937 cells in the presence or absence of lipopolysaccharide, anti-CD43 antibody, fibronectin, and phorbal 12-myristate 13-acetate. Therefore, our results suggest that 2H-PPT can be applied as a novel functional immunoregulator of macrophages and monocytes.

• Proceedings of the Materials Research Society of Korea Conference
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• 2009.11a
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• pp.3.2-3.2
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• 2009

Microfluidics and BioMEMStechnology has increasingly been used as a tool for studying small volumes oftissue and even individual cells. One of the most important benefits ofmicrofluidic technology is the potential to build devices that analyze and sortmammalian cells. The "sorting problem" typically requires that a fewcells be selected and isolated from a larger population of hundreds, thousandsor even millions of other cells. For example, cancer tumor cells may resideamong a large population of healthy cells, but it would be of great interest toidentify, isolate and study only the cancer cells. In another application, onemay want to determine the number of white blood cells within a sample of blood.We have developed microfluidic devices that enable researchers to select cellsfrom a population by a variety of methods, including antibody staining,dielectrophoretic selection, and physical size selection. These devices haveapplications in cancer research where cancer cells must be identified fromnormal tissue, but where only small samples of tissue are available. In thistalk, we will present some of our microfluidic cell sorting devices, discusstheir physical principles, and their use in biological applications.

• Biotechnology and Bioprocess Engineering:BBE
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• v.2 no.2
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• pp.73-76
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• 1997

Biopolymer membrane was prepared using two oppositely charged natural biopolymer. The biopolymer membrane was used for the encapsulation of two hybridoma cell lines(ATCC CRL-1606, ATCC BH-8852) to produce monoclonal antibodies. In order to reduce the down stream steps, the pore size of the membrane was controlled to retain the monoclonal antibodies in the capsules based on the diffusion experiments with standard proteins. T-flask culture showed cell densities of 8$\times$107cells/mL 3$\times$107cells/mL, and MAb concentrations of 506 $\mu\textrm{g}$/mL and 109$\mu\textrm{g}$/mL for encapsulated ATCC CRL-1606 and HB-8852, respectively. Two liter perfusion culture with encapsulated ATCC HB-8852 was performed to enhance the MAb production. The MAb production of the encapsulated hybridoma increased considerably comparing to the culture using silicone tubing for oxygen transfer.

• Journal of environmental and Sanitary engineering
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• v.12 no.2
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• pp.59-64
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• 1997

For purification of a 70kDa toxic protein of mosquitocidal delta-endotoxin from B. thuringiensis strain H9B, immuno-affinity chromatography was performed. After separation of 70kDa toxic proteins from the delta-endotoxin of the strain H9B on SDS-PAGE, the 70kDa toxic protein was subcutaneously injected into rabbit for making a polyclonal antibody. A anti-70kDa toxic protein was purified by a column chromatography packed with protein A-sepharose 4B gels. The 70kDa toxic protein from delta-endotoxin of the strain H9B was also purified by an immuno-affinity chromatography packed with CNBr-activated sepharose 4B gels conjugated anti-70kDa toxic protein after elution with 1/10M citric acid-1/5M Na$_{2}$HPO$_{4}$ buffer(pH3.2) containing 0.5M NaCl. The 70kDa toxic protein was purified through only one step-separation system, was demonstrated by SDS-PAGE and immunoblot.

• Journal of Korean Port Research
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• v.13 no.2
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• pp.389-398
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• 1999

In the biological immunity, the immune system of organisms regulates the antibody and T-cells to protect the attack from the foreign materials which are virus, germ cell, and other antigens, and supports their stable state. It has similar characteristics that has the adaptation and robustness to overcome disturbances and to control the plant of engineering application. In this paper, we build a model of the T-cell regulated immune response mechanism. We have also designed an immune response controller(IRC) focusing on the T-cell regulated immune response of the biological immune system that include both a help part to control the response and a suppress part to adjust system stabilization effect. We show some computer simulation to control the vibration of building structure system with strong wind forces excitation also demonstrate the efficiency of the proposed controller for applying a practical system even with existing nonlinear terms.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2014.10a
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• pp.989-992
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• 2014

Myelination using Schwann cells and neuron cells was performed in rat. Schwann cells and neuron cells from dorsal root ganglion (DRG) of rat embryos (E16) were cultured, respectively. The embryonic DRG cells purified were cultured and anti-mitotic agents were added. Purified the embryonic Schwann cells were cultured and added to the embryonic DRG cells purified. A purified population of myelination in vitro system was accomplished and identified formation of myelination using antibody of neurofilament protein.

• Proceedings of the PSK Conference
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• 2003.10b
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• pp.164.2-164.2
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• 2003

Human embryonic stem (ES) cell lines derived from the inner cell mass of human blastocysts have potential to differentiate into any cell types. We have established in vitro neural differentiation of human ES cells. After the formation of embroid bodies (EBs), the differentiating EBs formed neural tube-like rosettes in the presence of basic fibroblast growth factor (bFGF). The rosettes were selectively isolated by the treatment of dispase and cultured in a medium for human neural precursors in the presence of bFGF. (omitted)

• Asian Journal of Atmospheric Environment
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• v.6 no.1
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• pp.33-40
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• 2012

In this study, we characterized the physical form of allergenic Cry j 1 in the urban atmosphere. Through an immunofluorescence antibody method, we showed that allergenic Cry j 1 exists as fine particles (${\leq}1.1{\mu}m$). To determine Cry j 1 concentrations and its particle size distribution, we used the ELISA method to confirm that most Cry j 1 exists as fine particles in the urban atmosphere and is found at high concentrations on fine day next to rainy day. Furthermore, we evaluated Cry j 1 denaturation by using the Biacore J system based on the surface plasmon resonence (SPR) principle and sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE). We showed that the dissociation constant ($K_D$) of Cry j 1 that has been exposed to urban polluted air is lower ($1.76{\times}10^{-14}$ M) than that of Cry j 1 ($1.32{\times}10^{-9}-3.37{\times}10^{-9}$ M) of original pollen grains that has not been exposed to air pollutants. Cry j 1 turns into low molecular weight proteins by reacting with various acidic solutions. In sum, we showed that allergenic Cry j 1 exists as fine particles that can deposit in the lower respiratory tract. This finding clarifies the relationship between Japanese cedar pollinosis and air pollutants.

• Korean Journal of Microbiology
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• v.30 no.2
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• pp.108-112
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• 1992

To investigate the expression and the secretion of heterologous proteins in yeast, we constructed an yeast secretion vector and produced a human secretory protein, .alpha.-1-antitrypsin (.alpha.-1-AT), from yeast cells. The secretion vector pGAT8 was constructed by inserting the signal sequence of yeast acid phosphatase gene (PH05) into the .alpha.1-AT expression vector pGAT6 which contained .alpha.-1-AT cDNA fused to GAL10-CYC1 promotor. The .alpha.-1-AT was produced efficiently in the yeast cells transformed with plasmid pGAT8, which was onfirmed both by the .alpha.-1-AT activity assay and by the immunoblot method using .alpha.-1-AT antibody. We also showed the secretion of .alpha.-1-AT into the culture media and into the periplasmic space by immunoblot.