• The Transactions of The Korean Institute of Electrical Engineers
• /
• v.60 no.7
• /
• pp.1417-1426
• /
• 2011

Radiofrequency ablation through cardiac catheterization is one of minimally invasive intervention procedures used in drug resistant arrhythmia treatment. To facilitate more accurate and precise catheter navigation, systems for robotic cardiac catheter navigation have been developed and commercialized. The authors have been developing a novel robotic catheter navigation system. The system is a network-based master-slave configuration 3-DOF (Degree-Of-Freedom) robotic manipulator for operation with conventional cardiac ablation catheter. The catheter manipulation motion is composed of the translation (forward/backward) and the roll movements of the catheter and knob rotation for the catheter tip articulation. The master manipulator comprises an operator handle compartment for the knob and the roll movement input, and a base platform for the translation movement input. The slave manipulator implements a robotic catheter platform in which conventional cardiac catheter is mounted and the 3-DOF motions of the catheter are controlled. The system software that runs on a realtime OS based PC, implements the master-slave motion synchronization control in the robot system. The master-slave motion synchronization performance tested with step, sinusoidal and arbitrarily varying motion commands showed satisfactory results with acceptable level of steady state error. The developed system will be further improved through evaluation of safety and performance in in vitro and in vivo tests.

• Bulletin of the Korean Chemical Society
• /
• v.34 no.3
• /
• pp.735-742
• /
• 2013

Peptide nucleic acids (PNAs) that bind to complementary nucleic acid sequences with extraordinarily high affinity and sequence specificity can be used as antisense oligonucleotides against microRNAs, namely antagomir PNAs. However, methods for efficient cellular delivery must be developed for effective use of PNAs as therapeutic agents. Here, we demonstrate that antagomir PNAs can be delivered to hepatic cells by complementary DNA oligonucleotide and cationic liposomes containing galactosylated ceramide and a novel cationic lipid, DMKE (O,O'-dimyristyl-N-lysyl glutamate), through glycoprotein-mediated endocytosis. An antagomir PNA was designed to target miR-122, which is required for translation of the hepatitis C virus (HCV) genome in hepatocytes, and was hybridized to a DNA oligonucleotide for complexation with cationic liposome. The PNA-DNA hybrid molecules were efficiently internalized into hepatic cells by complexing with the galactosylated cationic liposome in vitro. Galactosylation of liposome significantly enhanced both lipoplex cell binding and PNA delivery to the hepatic cells. After 4-h incubation with galactosylated lipoplexes, PNAs were efficiently delivered into hepatic cells and HCV genome translation was suppressed more than 70% through sequestration of miR-122 in cytoplasm. PNAs were readily released from the PNA-DNA hybrid in the low pH environment of the endosome. The present study indicates that transfection of PNA-DNA hybrid molecules using galactosylated cationic liposomes can be used as an efficient non-viral carrier for antagomir PNAs targeted to hepatocytes.

• Korean Journal of Medicinal Crop Science
• /
• v.15 no.1
• /
• pp.46-50
• /
• 2007

Transformed hairy roots were induced from in vitro grown plantlets of Trichosanthes kirilowii by infection with Agrobacterium rhizogenes strain ATCC15834. Transformed hairy roots exhibited active growth with high branching of roots on plant growth regulators-free medium. Cloned line (TR-03) of hairy root was tested for its growth and extracellular protein accumulation in medium under various culture conditions. Among the culture media tested, a full-strength MS medium had a pronounced effect on root biomass and extracelluar protein accumulation in medium. The maximum root biomass (2.4 g DRW/flask) and extracellular total protein contents $(28.3ug/m\ell)$ in medium was obtained at inoculum size of 2 g (FRW) and in MS medium supplemented with 4% sucrose. In addition, the optimal shaking speed for root growth and extracellular protein accumulation in medium were 100 rpm. The total extracellualr protein concentration reached a maximum of $28.3ug/m\ell$ at 4 weeks and decreased thereafter. Protein translation inhibitory activity was observed in culture broths and reached levels of 21.3 unit. These studies demonstrate that the transformed hairy roots can be utilized for the in vitro production of ribosome-inactivating proteins.

• Journal of Plant Biotechnology
• /
• v.37 no.1
• /
• pp.89-95
• /
• 2010

Dihydroflavonol 4-reductase (DFR) is a key enzyme of the flavonoid biosynthesis pathway which catalyses the NADPH-dependent reduction of 2R,3R-trans-dihydroflavonols to leucoanthocyanidins. In this study we describe cloning and expression of the genes encoding the flavonoid-biosynthetic enzyme DFR in Gypsophila paniculata L. Inspection of the 1279 bp long sequence revealed an open reading frame 1063 bp, including a 36 bp 5' leader region and 181 bp 3' untranslated region. Comparison of the coding region of this DFR cDNA sequence including the sequences of Arabidopsis thaliana, Citrus sinensis, Dianthus caryophyllus, Ipomoea batatas, Matthiola incana, Nierembergia sp, Petunia hybrida, Solanum tuberosum, Vitis vinifera reveals an identity higher than 69% at the nucleotide level. The function of this nucleotide sequences was verified by comparison with amino acid sequences of the amino-terminus and tryptic peptides from purified plant enzyme, by northern blotting with mRNA from wild type and mutant plants, by in vitro expression yielding and enzymatically active reductase, as indicated by the small leucopelargonidin peak. Genomic southern blot analysis showed the presence of only one gene for DFR in Gypsophila paniculata.

• Journal of Life Science
• /
• v.23 no.11
• /
• pp.1311-1316
• /
• 2013

Heterogeneous nuclear ribonucleoprotein L (hnRNP L) is a major pre-mRNA binding protein and it is an abundant nuclear protein that shuttles between the nucleus and the cytoplasm. hnRNP L is known to be related to many cellular processes, including chromatin modification, pre-mRNA splicing, mRNA export of intronless genes, internal ribosomal entry site (IRES)-mediated translation, mRNA stability, and spermatogenesis. In order to identify the cellular proteins interacting with hnRNP L, this study performed a yeast two-hybrid screening, using a human liver cDNA library. The study identified insulin-like growth factor binding protein-4 (IGFBP-4) as a novel interaction partner of hnRNP L in the human liver. It then discovered, for the first time, that hnRNP L interacts specifically with IGFBP-4 in a yeast two-hybrid system. The authenticity of this two-hybrid interaction of hnRNP L and IGFBP-4 was confirmed by an in vitro pull-down assay.

• The Korean Journal of Mycology
• /
• v.21 no.1
• /
• pp.28-37
• /
• 1993

An endo-type cellulase, carboxymethyl cellulase(CMCase) IV, was purified from culture filtrate of cellulolytic fungus Penicillium verruculosum. The CMCase IV was acidic glycoprotein having carbohydrate of 13% as glucose and pI value of 4.0. The CMCase IV was 52 KDa of molecular weight in SDS-polyacrylamide gel electrophoresis and have optimum temperature and pH of $50^{\circ}C$ and 5.0 for enzyme activity. The CMCase IV liberated glucose and cellobiose as major products of the enzyme against carboxymethyl cellulose(CMC) and seemed to has transglycosylation activity simultaneously. Cellulase activity staining(zymogram) showed that the cellulase components of P. verruculosum were not aggregated in the medium. P. vrttuculosum mRNA was translated in vitro and translation product by the mRNA coding for CMCase IV was identified by immunoprecipitation.

• Asian-Australasian Journal of Animal Sciences
• /
• v.16 no.11
• /
• pp.1690-1694
• /
• 2003

The large and rapid changes of glucose utilization in lactating mammary tissue in response to changes in nutritional state must be largely related by external signal of insulin. This also must be related with the quantity and composition of the diet in vivo. To characterize the mode of growth factors and gut regulatory peptides with insulin, in vitro experiment was conducted with HC11 cells. All the growth factor alone and the combinations of growth factors significantly (p<0.05) increased in glucose uptake. Insulin, EGF and IGF-1 exhibited a stimulation of glucose uptake for at least 24 h. Furthermore, the highest (p<0.05) synergistic effect was shown in EGF plus IGF-1 and the second synergistic effect in insulin plus EGF while no synergistic effect was found between insulin and IGF-1. However, the gut regulatory peptides neither potentiated nor inhibited the action of insulin on glucose uptake. Although growth factors did not modulates glucose uptake via increasing the rate of translation of the GLUT1 protein, RT-PCR analysis indicated that the growth factors significantly (p<0.05) increased the expression of GLUT1. The growth factors are therefore shown to be capable of modulating glucose uptake by transcription level with insulin in HC 11 cells.

• IMMUNE NETWORK
• /
• v.13 no.1
• /
• pp.16-24
• /
• 2013

CTLA-4Ig is regarded as an inhibitory agent of the T cell proliferation via blocking the costimulatory signal which is essential for full T cell activation. To improve applicability, we developed the CTLA-4Ig-CTKC in which the c-terminal lysine had been replaced by cysteine through single amino acid change. The single amino acid mutation of c-terminus of CTLA-4Ig was performed by PCR and was checked by in vitro transcription and translation. DNA construct of mutant form was transfected to Chinese hamster ovary (CHO) cells by electroporation. The purified proteins were confirmed by Western blot and B7-1 binding assay for their binding ability. The suppressive capacity of CTLA-4Ig-CTKC was evaluated by the mixed lymphocyte reaction (MLR) and in the allogeneic pancreatic islet transplantation model. CTLA-4Ig-CTKC maintained binding ability to B7-1 molecule and effectively inhibits T cell proliferation in MLR. In the murine allogeneic pancreatic islet transplantation, short-term treatment of CTLA-4Ig-CTKC prolonged the graft survival over 100 days. CTLA-4Ig-CTKC effectively inhibits immune response both in MLR and in allogeneic islet transplantation model, indicating that single amino acid mutation does not affect the inhibitory function of CTLA-4Ig. CTLA-4Ig-CTKC can be used in vehicle-mediated drug delivery system such as liposome conjugation.

• Molecules and Cells
• /
• v.46 no.1
• /
• pp.33-40
• /
• 2023

RNAs are versatile molecules that are primarily involved in gene regulation and can thus be widely used to advance the fields of therapeutics and diagnostics. In particular, circular RNAs which are highly stable, have emerged as strong candidates for use on next-generation therapeutic platforms. Endogenous circular RNAs control gene regulatory networks by interacting with other biomolecules or through translation into polypeptides. Circular RNAs exhibit cell-type specific expression patterns, which can be altered in tissues and body fluids depending on pathophysiological conditions. Circular RNAs that are aberrantly expressed in diseases can function as biomarkers or therapeutic targets. Moreover, exogenous circular RNAs synthesized in vitro can be introduced into cells as therapeutic molecules to modulate gene expression networks in vivo. Depending on the purpose, synthetic circular RNA sequences can either be identical to endogenous circular RNA sequences or artificially designed. In this review, we introduce the life cycle and known functions of intracellular circular RNAs. The current stage of endogenous circular RNAs as biomarkers and therapeutic targets is also described. Finally, approaches and considerations that are important for applying the available knowledge on endogenous circular RNAs to design exogenous circular RNAs for therapeutic purposes are presented.

• Journal of Microbiology and Biotechnology
• /
• v.15 no.2
• /
• pp.403-411
• /
• 2005

The relationship between plasmid (~9.5 kb) and pediocin PA-1 in P. acidilactici K10 was confirmed by plasmid curing. The pediocin operon of P. acidilactici K10 was amplified by PCR (polymerase chain reaction), and the nucleotide sequence was analyzed. The sequence of the pediocin operon of P. acidilactici K10 was similar to those of P. acidilactici strains producing pediocin PA-1/ AcH. For the expression of pediocin PA-1 in E. coli, a pQEPED (pQE-30 Xa::mature pedA) was constructed. His-tagged recombinant pediocin PA-1 (-6.5 kDa) was translated by cell-free in vitro transcription and translation using pQEPED as a DNA template. Theresult of slot blotting assay showed that transcription of recombinant pedA in E. coli M15 was induced by the addition of isopropyl-$\beta$-D-thiogalactopyranoside (IPTG) at the final concentration of 1 mM. Although the recombinant pediocin PA-1 inhibited the growth of E. coli, it was expressed in the host strain and purified by nickel-nitrilotriacetic acid (Ni-NTA) metal-affinity chromatography under denaturing condition. This is the first report for the production and one-step purification of biologically active recombinant pediocin PA-1 in E. coli.