Publications by authors named "SeungJin Lee"

The aim of the present study was to test the osteogenic effects of BMP-2 (bone morphogenetic protein-2) gene transfer in BMSCs (bone-marrow stromal cells) and rabbit calvarial bone defects. The pBMP-2-cDNA3.1 plasmid was constructed by subcloning hBMP-2 (human BMP-2) cDNA into the plasmid pcDNA3.

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Article Synopsis
  • Bioactive scaffolds, like collagen, are essential for promoting cell adhesion and differentiation, particularly in bone regeneration.
  • The collagen-binding motif (CBM) peptide from osteopontin can bind to collagen without any chemicals, enhancing its ability to encourage mineralization.
  • In vivo studies show that the combination of the CBM peptide and collagen significantly aids in bone formation, making it a promising option for bone regeneration applications.
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To obtain predominant bacteria degrading crude oil, we isolated some bacteria from waste soybean oil. Isolated bacterial strain had a marked tributyrin (C4:0) degrading activity as developed clear zone around the colony after incubation for 24h at 37 degrees C. It was identified as Klebsiella sp.

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Fibroblast growth factor (FGF)-2 regulates a variety of cellular functions, such as proliferation and differentiation, by binding to cell surface FGF receptors (FGFRs) in the presence of heparin proteoglycans. FGF-2 is known as a heparin-binding growth factor, but the localization of the heparin binding site has not been fully investigated until now. We used two potential heparin binding domains of FGF-2, the residues 105-111 (F105, YKRSRYT) and 119-135 (F119, KRTGQYKLGSKTGPGQK).

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A synthetic peptide denoted as collagen-binding motif (CBM) was identified from osteopontin (OPN), a multisubunit extracellular matrix (ECM) protein, by enzymatic digestion with chymotrypsin. The aim of this study was to examine the feasibility of identified CBM peptide as an active component of gel type scaffold material in osteogenesis. The binding of CBM peptide to collagen was specific and presented high affinity.

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Sustained-releasing praziquantel (SRP) tablet was designed for single dose treatment regimen of clonorchiasis. A previous pre-clinical study confirmed its sustained-releasing characteristics and a better cure rate than conventional praziquantel (PZQ). In this clinical study, the pharmacokinetics of this SRP tablet were investigated in human volunteers (phase 1; 12 volunteers), and its curative efficacy was examined in clonorchiasis patients (phase 2; 20 volunteers).

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Myeloid Elf-1 like factor (MEF) is a member of the Ets transcription factor family. Ets family proteins control the expression of genes that are critical for biological processes such as proliferation, differentiation, and cell death. Some of Ets factors are also known to regulate bone development.

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The polyphosphate (polyP) operon was cloned from a genomic library of Serratia marcescens KCTC 2172 by Southern hybridization using E. coli ppk gene as a probe. The polyP operon was composed of a polyphosphate promoter, polyphosphate kinase (ppk) and exopolyphosphatase (ppx).

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Runx2 is a key transcription factor in osteoblast differentiation, and its activity is regulated by fibroblast growth factors (FGFs). Craniosynostosis, characterized by premature suture closure, results from mutations that generate constitutively active FGF receptors (FGFRs). We previously showed that FGF/FGFR-activated protein kinase C (PKC) is involved in the expression and activity of Runx2.

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Majority of cancer cells upregulate co-inhibitory molecule B7-H1 which confers resistance to anti-tumor immunity, allowing cancers to escape from host immune surveillance. We addressed the molecular mechanism underlying the regulation of cancer-associated B7-H1 expression in response to interferon-gamma (IFN-gamma). Using promoter constructs in luciferase assay, the region between 202 and 320 bp from the translational start site is responsible for B7-H1 expression.

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Collagen/chitosan composite microgranules were fabricated as bone substitutes for the purpose of obtaining high bone-forming efficacy. The microgranules have the flexibility to fill various types of defect sites with closer packing. The interconnected pores formed spaces between the microgranules, which allowed new bone ingrowth and vascularization.

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Background: Chitosan is known as a biodegradable and non-toxic natural polymer that enhances wound healing and bone formation. The aims of this study are to evaluate the biocompatibility of chitosan nanofiber membranes and to examine the effect of the chitosan nanofiber membranes on bone regeneration in rabbit calvarial defects.

Methods: In vitro cell proliferation tests using human osteosarcoma cell line MG63 and reverse transcription-polymerase chain reaction (RT-PCR) to evaluate the expression of alkaline phosphatase (ALP), collagen, osteocalcin (OCN), and GAPDH were done on chitosan nanofiber membranes.

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It has been reported that iron can generate reactive oxygen species (ROS) with thiols. In this study, we examined the interaction of iron with thiols in plasma and the generation of ROS. In human plasma, unlike with Fe(3+), treatment with Fe(2+) increased lucigenin-enhanced chemiluminescence in a concentration-dependent manner, and this was inhibited by superoxide dismutase.

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Purpose: Tricalcium phosphate (TCP)/chitosan composite microgranules were developed as bone substitutes and tissue engineering scaffolds with the aim of obtaining a high bone forming efficacy. The microgranules have the ability to fill various types of defect sites with closer packing. In addition, the transforming growth factor-beta 1 (TGF-beta1) was added to the microgranules in order to improve bone-healing efficacy.

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Rat calvarial osteoblasts were grown in porous chitosan sponges fabricated by freeze drying. The prepared chitosan sponges had a porous structure with a 100-200 microm pore diameter, which allowed cell proliferation. Cell density, alkaline phosphatase activity and calcium deposition were monitored for up to 56 d culture.

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Eperisone hydrochloride is widely used for the treatment of plasticity to relieve muscle stiffness and back pain. However, oral eperisone has a very low bioavailability and short muscle relaxant activity, because of the profound intestinal first-pass metabolism. To improve the efficacy and compliance of eperisone, we designed a new dosage form, a transdermal patch, and evaluated the efficacy of the eperisone patch with the muscle relaxant activity of rats.

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Praziquantel is rapidly absorbed and secreted; and thus fractional doses are recommended for the treatment of cestode and trematode infections. In the present study, we developed a new praziquantel tablet formula allowing sustained-release (SRP). In vitro dissolution of SRP tablets showed that praziquantel at 300 mg/tablet combined with hydroxypropyl methylcellulose dissolved completely at a constant rate over 10 h, whereas the conventional praziquantel tablet (PZQ) was only 40% dissolved.

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Background: The present study was undertaken to determine the effect of recombinant human bone morphogenetic protein-2 (rhBMP-2)-loaded biodegradable membranes on bone augmentation in a rabbit calvarial model.

Methods: Five microg of rhBMP-2 was loaded into a stiff hemispherical dome membrane made of poly(L-lactide) and tricalcium phosphate (PLLA/TCP). The release kinetics of rhBMP-2 from the membrane were determined in vitro using a human BMP-2 immunoassay.

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To understand the mechanism of phosphate accumulation, a gene encoding polyphosphate kinase (PPK) was cloned from the genomic library of Serratia marcescens by Southern hybridization. From the nucleotide sequence of a 4 kb DNA fragment, an open reading frame of 2063 nucleotides was identified encoding a protein of 686 amino acids with molecular mass of 70 kDa. The potential CRP binding site and pho box sequence were found upstream of the putative promoter in the regulatory region.

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Colon drug delivery is advantageous in the treatment of colonic disease and oral delivery of drugs unstable or suceptible to enzymatic degradation in upper GI tract. In this study, multilayer coated system that is resistant to gastric and small intestinal conditions but can be easily degraded by colonic bacterial enzymes was designed to achieve effective colon delivery of prednisolone. Variously coated tablets containing prednisolone were fabricated using chitosan and cellulose acetate phthalate (CAP) as coating materials.

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Carbon monoxide (CO) are produced by heme oxygenase (HO), and HO was detected in hypothalamus. However, the roles of CO produced in hypothalamus was not fully elucidated. So, we tested the effects of CO on body temperature because preoptic-anterior hypothalamus was known as the presumptive primary fever-producing site.

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For the purpose of obtaining high bone forming efficacy, development of chitosan was attempted as a tool useful as a scaffolding device. Porous chitosan matrices, chitosan-poly(L-lactide) (PLLA) composite matrices and chitosan coated on PLLA matrices were dealt with in this research. Porous chitosan matrix was fabricated by freeze-drying and cross-linking aqueous chitosan solution.

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