Identification and functional analysis of vibrio vulnificus SmcR, a novel global regulator.

Recently, quorum sensing has been implicated as an important global regulator controlling the production of numerous virulence factors such as capsular polysaccharides in bacterial pathogens. The nucleotide and deduced amino acid sequences of smcR, a homolog of V. harveyi luxR identified from V.

Enhancing effects of ceramide derivatives on 1,25-dihydroxyvitamin D(3)-induced differentiation of human HL-60 leukemia cells.

Differentiation-inducing therapy by agents such as 1,25-dihydroxyvitamin D(3) [1,25-(OH)(2)D(3)] represents a useful approach for the treatment for cancer, including acute myeloid leukemia (AML). Recent studies demonstrated that the combined administration of 1,25-(OH)(2)D(3) and differentiation-enhancing agents could alleviate the side effects of 1,25-(OH)(2)D(3) and improve the rate of long term survival. In this study, we determined the enhancing activities of ceramide derivatives on 1,25-(OH)(2)D(3)-induced differentiation of human myeloid leukemia HL-60 cells.

Integrated PET/CT of salivary gland type carcinoma of the lung in 12 patients.

Objective: The purpose of our study was to show the integrated 18F-FDG PET/CT findings of salivary gland type carcinomas of the lung.

Conclusion: Salivary gland type carcinomas of the lung appear as airway tumors with variable CT morphologies and show different patterns and extents of FDG uptake on PET images according to their grades of differentiation.

Indeno[1,2-c]isoquinolines as enhancing agents on all-trans retinoic acid-mediated differentiation of human myeloid leukemia cells.

Induction of differentiation is a new and promising approach to cancer therapy, well illustrated by the treatment of acute myeloid leukemia with all-trans retinoic acid (ATRA). Using combination of ATRA and chemotherapy, adverse effects such as retinoic acid syndrome have decreased, and long-term survival has improved. In this study, we demonstrated that the indeno[1,2-c]isoquinolines markedly enhanced differentiation of human myeloid leukemia HL-60 and NB4 cells when simultaneously combined with a low dose of ATRA.

Micro capsule endoscope for gastro intestinal tract.

A novel capsule endoscope (CE) named "MiRo" was developed based on a completely new transmission technology known as "electric-field propagation." This technology marks the initial achievement of cooperative research between the Intelligent Microsystem Center of KIST, IntroMedic Co., Ltd, and Yonsei University College of Medicine under Korea's Frontier 21 project.

A Multi-center Clinical Study of Posterior Lumbar Interbody Fusion with the Expandable Stand-alone Cage (Tyche(R) Cage) for Degenerative Lumbar Spinal Disorders.

Objective: This multi-center clinical study was designed to determine the long-term results of patients who received a one-level posterior lumbar interbody fusion with expandable cage (Tyche(R) cage) for degenerative spinal diseases during the same period in each hospital.

Methods: Fifty-seven patients with low back pain who had a one-level posterior lumbar interbody fusion using a newly designed expandable cage were enrolled in this study at five centers from June 2003 to December 2004 and followed up for 24 months. Pain improvement was checked with a Visual Analogue Scale (VAS) and their disability was evaluated with the Oswestry Disability Index.

Convenient synthesis of indeno[1,2-c]isoquinolines as constrained forms of 3-arylisoquinolines and docking study of a topoisomerase I inhibitor into DNA-topoisomerase I complex.

11-hydroxyindeno[1,2-c]isoquinolines 12a-c were prepared as constrained forms of 3-arylisoquinolines through an intramolecular cyclization reaction. Among the synthesized compounds, the 11-(i)butoxy analog 15l displayed potent in vitro cytotoxicity against four different tumor cell lines as well as topoisomerase 1 inhibitory activity. A FlexX docking study was performed to explain the topoisomerase 1 activity of 15l.

A microfluidic protease activity assay based on the detection of fluorescence polarization.

This article describes a fluorescence polarization (FP)-based protease assay on a microfluidic device that is compatible with fast and reproducible analyses of protease activities. The optical systems were arranged for simultaneously measuring fluorescence intensities of vertical and horizontal polarization planes, and the binding of tetramethylrhodamine (TMR) labeled-biotin with streptavidin was utilized for optimizing FP detection in continuously flowing solutions within 74-microm wide, 12-microm deep microchannels of a glass chip. In developing off-chip FP-based assays for proteinase K, trypsin, papain and elastase, TMR conjugated-casein protein (TMR-alpha-casein) was employed as a universal substrate.

A Mach-Zehnder interferometer based on silicon oxides for biosensor applications.

Integrated optical devices have been increasingly interested in biosensor applications including environmental pollution, biological process and medical diagnostics. Integrated optics allows high-detection sensitivity to be achieved using optical transduction techniques in a microfluidic format. Among different transduction techniques, a Mach-Zehnder interferometer (MZI) has advantage of its inherent high sensitivity and accuracy.

Putative chemosensitivity predictive genes in colorectal cancer cell lines for anticancer agents.

In order to identify genes which could predict chemosensitivity in colorectal cancer, gene expression and chemosensitivity were examined in colorectal cancer cell lines. Gene expression profiling of 5 colorectal cancer and 3 normal cell lines was performed using a 22K spotted oligonucleotide microarray. The IC50s of 17 anticancer drugs were determined using the MTT assay for chemosensitivity.

Suppressive effects of bisphenol A on the proliferation of neural progenitor cells.

Endocrine disruptors (EDs) exert adverse effects on reproductive and immune function or neurological behavior. Bisphenol A (BPA), one of the environmental EDs, is widely used in the manufacture of plastics and epoxy resins. Studies reported that BPA affects reproductive organ growth and development.

Nanomechanical microcantilever operated in vibration modes with use of RNA aptamer as receptor molecules for label-free detection of HCV helicase.

We report the nanomechanical microcantilevers operated in vibration modes (oscillation) with use of RNA aptamers as receptor molecules for label-free detection of hepatitis C virus (HCV) helicase. The nanomechanical detection principle is that the ligand-receptor binding on the microcantilever surface induces the dynamic response change of microcantilevers. We implemented the label-free detection of HCV helicase in the low concentration as much as 100 pg/ml from measuring the dynamic response change of microcantilevers.

Phase behavior of mixed solution of a glycerin-modified cationic surfactant and an anionic surfactant.

The phase behavior of mixed solution of newly synthesized monoglycerylcetyldimethylammonium chloride (MGCA) and sodium octyl sulfate (SOS) in water was investigated by cryo-transmission electron microscopy (cryo-TEM), dynamic light scattering (DLS), differential scanning calorimetry (DSC), and fluorescence polarizing for evaluation of the microviscosity of bilayers. No precipitate was observed in the mixed solution except at concentrations below 20 mM over all mixing ratios, and stable vesicles were formed in a considerably wide range of mixing ratio, even at the equimolar ratio. Vesicles formed in aqueous 1/1 MGCA/SOS mixture were found to exhibit no phase transition, and fluorescence polarizing measurements showed that the vesicle bilayers have a high fluidity.

[Development of micro/nano devices for cancer diagnosis].

In order to rapidly detect and analyze the presence of a target ligand of interests in environmental or industrial fluids as well as biological samples, numerous test systems have been designed and developed, which have been based on the combination of a test reagent and absorbing paper or membrane. The main limitations of these conventional devices are the difficulty of quantitative or semi-quantitative detection and poor detection limit (around nanogram/ml range detection capability). In this paper, new approaches and research trends which use nano/MEMS (micro electro mechanical systems) technology is introduced, which has a concept of fast, precise, and massive diagnosis and analysis of target molecules using very small amount of samples.

Identification and characterization of the Vibrio vulnificus rtxA essential for cytotoxicity in vitro and virulence in mice.

A mutant exhibiting decreased cytotoxic activity toward INT-407 intestinal epithelial cells and carrying a mutation in the rtx gene cluster that consists of rtxCA and rtxBDE operons was screened from a library of V. vulnificus mutants. The functions of the rtxA gene, assessed by constructing an isogenic mutant and evaluating its phenotypic changes, demonstrated that RtxA is essential for the virulence of V.

The Korean research & development program on micro-electro-mechanical systems (MEMS) in medical applications.

Non or minimally invasive approaches for medical applications are very important for the alleviation of patient complaints. The miniaturization of medical devices using micro & nano technologies might be one of the possible solutions. Several national research and development (R&D) programs have been launched by the Korean government to further the development of biological & medical micro/nano devices in this country.

Inhibition of interleukin-12 production in mouse macrophages via suppression of nuclear factor-kappaB binding activity by Phyllostachys nigra var. henonis.

Pharmacological inhibition of interleukin-12 (IL-12) production may be a therapeutic strategy for preventing development and progression of disease in experimental models of autoimmunity. The acetone fraction prepared from bamboo, Phyllostachys nigra var. henonis, potently inhibited the Lipo polysaccharide (LPS)-induced IL-12 production from RAW264.

Enhancement of 1,25-dihydroxyvitamin D3- and all-trans retinoic acid-induced differentiation of human leukemia HL-60 cells by Phyllostachys nigra var. henonis.

Human myeloid leukemia HL-60 cells are differentiated into monocytic or granulocytic lineage when treated with 1,25-dihydroxyvitamin D(3) [1,25-(OH)(2)D(3)] or all-trans retinoic acid (RA), respectively. In this study, the effect of acetone fraction prepared from bamboo leaf on cell differentiation was investigated in a HL-60 cell culture system. Treatment of HL-60 cells with 50-400 microg/ml acetone fraction of bamboo leaf for 72 hr inhibited cell proliferation and induced a little increase in cell differentiation, as demonstrated by the MTT and nitroblue tetrazolium reduction assay.

Chronic expanding hematoma of the thorax.

We report the first case in Korea of a chronic expanding hematoma, which presented as a huge mass in the pleural cavity. A 67-year-old woman exhibiting a slowly-expanding intrathoracic mass, as revealed by a chest radiograph, was admitted to our hospital. The patient had undergone a pneumonectomy 37 years earlier during treatment for pulmonary tuberculosis.

A rare case of hyperfunctioning papillary carcinoma of the thyroid gland.

We report a rare case of hyperfunctioning papillary carcinoma of the thyroid. A 32-year-old man was referred to our hospital for the treatment of a painless mass in the left neck, which had been detected on routine physical check-up. Cervical ultrasonography and computed tomography showed a solid tumor with calcification in the left lobe of the thyroid gland.

Allergic bronchopulmonary aspergillosis coupled with broncholithiasis in a non-asthmatic patient.

Allergic bronchopulmonary aspergillosis (ABPA), an asthmatic disease, is caused primarily by hypersensitivity to Aspergillus species. ABPA is rarely observed in the absence of asthma, which is, in fact, the principle criterion for its diagnosis. Here, we report the case of a 36-yr-old woman without a history of bronchial asthma, who manifested a localized pneumonic consolidation, coupled with broncholithiasis.

Site-directed biotinylation of antibodies for controlled immobilization on solid surfaces.

Site-directed biotinylation of antibodies at the hinge region was developed to immobilize antibodies in an oriented manner via biotin-streptavidin linkage. When intact antibody was biotinylated with maleimide-activated biotin after reduction, the reaction preferentially occurred at the sulfhydryl groups between the C(H1) and the C(L) domains and, provided that the reagent concentration exceeded a certain level, at those between the C(H2) and the C(H2) domains at the hinge. Based on this result, we devised an approach in which free maleimide was added to compete with the activated biotin for the preferential sites between the C(H1) and the C(L) domains.

Inhibition of mouse macrophages interleukin-12 production: suppression of nuclear factor-kappaB binding activity by a specific factor isolated from Scapharca broughtonii.

Pharmacological inhibition of interleukin-12 (IL-12) production may allow a therapeutic strategy for preventing development and progression of disease in experimental models of autoimmunity. In this study we investigated the effects of an ethanol fraction of the Scapharca broughtonii, on the production of IL-12 by mouse macrophages stimulated with lipopolysaccharides (LPS). The ethanol fraction (S3) prepared from Scapharca broughtonii potently inhibited LPS-induced IL-12 production in the RAW264.