• Journal of Microbiology and Biotechnology
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• v.15 no.2
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• pp.388-394
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• 2005

In order to investigate the distribution of dominant Bifidobacterium species in intestinal microflora of Korean adults and seniors, SDS-PAGE profiles of whole cell proteins were used for the identification of bifidobacteria. To confirm the reliability of SDS-PAGE, the Bifidobacterium species identified by SDS-PAGE of whole cell proteins were validated by using 16S rDNA sequencing analysis. The results of SDS­PAGE corresponded well with those determined by the analysis of 16S rDNA sequencing. Based on the analysis of SDS-PAGE patterns on unidentified fecal strains which showed positive in fructose-6-phosphate phosphoketolase activity, B. adolescentis, B. longum, and B. bifidum were identified in the feces of adults, and B. adolescentis, B. longum, B. bifidum, B. breve, and B. dentium were identified in those of seniors. In most of the fecal samples tested, the predominant Bifidobacterium species consisted of only a few species, and differences in the distribution and numbers of Bifidobacterium species were observed between adults and seniors. B. adolescentis and B. longum were found to be the most common species in feces of adults, but not in seniors. Accordingly, the distribution and abundance of bifidobacteria in the human intestinal microflora varied depending on the age of hosts.

• Biomolecules & Therapeutics
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• v.27 no.1
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• pp.34-40
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• 2019

Transglutaminase 2 (TGase 2) plays a key role in p53 regulation, depleting p53 tumor suppressor through autophagy in renal cell carcinoma. We found that microtubule-associated protein 1A/1B-light chain 3 (LC3), a hallmark of autophagy, were tightly associated with the level of TGase 2 in cancer cells. TGase 2 overexpression increased LC3 levels, and TGase 2 knockdown decreased LC3 levels in cancer cells. Transcript abundance of LC3 was inversely correlated with level of wild type p53. TGase 2 knockdown using siRNA, or TGase 2 inhibition using GK921 significantly reduced autophagy through reduction of LC3 transcription, which was followed by restoration of p53 levels in cancer cells. TGase 2 overexpression promoted the autophagy process by LC3 induction, which was correlated with p53 depletion in cancer cells. Rapamycin-resistant cancer cells also showed higher expression of LC3 compared to the rapamycin-sensitive cancer cells, which was tightly correlated with TGase 2 levels. TGase 2 knockdown or TGase 2 inhibition sensitized rapamycin-resistant cancer cells to drug treatment. In summary, TGase 2 induces drug resistance by potentiating autophagy through LC3 induction via p53 regulation in cancer.

• KSBB Journal
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• v.16 no.3
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• pp.237-240
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• 2001

Epithelial cell migration plays an important role in many physiological processes such as morphogenesis and wound healing, and cell mobility requires the release of the cell from its adhesion site. This is directed, at least in part, by limited proteolysis of matrix molecules by matrix metalloproteinases (MMPs). MMPs are zinc-dependent proteases produced by a variety of cell types, and have a fundamental role in tissue remodelling, tumour invasion and metastasis. In addition, the ability of cells to mediate fibrinolytic agent, plasmin. The purpose of this study was to test if vascular endothlial growth factor (VEGF) can regulate the production of MMPs and plasmin by keratinocyte cells. Supernatants from a human keratinocyte cell line grown in the presence or absence of VEGF (10ng/mL) produced ?2.5 fold increases in cell proliferation, and ?3.0 fold increses in MMP-2 and plasmin levels. Our results suggest that VEGF may modulate keratinocyte cell proliferating activity by increasing the abundance of MMP-2 and plasmin, and indicates a role for VEGF in the regulation of keratinocyte behaviour in wound healing and tissue remodelling.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.28 no.2
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• pp.127-135
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• 2006

Objectives: The extent of bone formation that occurs at the interface of metallic implants and bone is determined by the number and activity of osteoblastic cells. Stress proteins may be contributing determinants of cell viability in altered environments. Hsp27 is a small Mr hsp which is known as a molecular chaperone. Methods: To better understand how heat shock protein 27 contributes to endosseous implant - associated metal ions affects on osteoblastic cell viability, the effect of chromium and titanium ions were compared to effects of cadmium ions in the ROS17/2.8 osteoblastic cell line. Results: ROS17/2.8 osteoblastic cell line demonstrated ion - specific reductions in growth; reductions were significantly greater for cadmium than for chromium or titanium. Chromium impaired growth of cultures without altering cell viability measured using the MTT assay. A stable transformed cell line expressing additional hsp27(clone "A7") was resistant to the toxic effects of titanium and partially protected from cadmium toxicity. Conclusions: A role for hsp27 in protection of osteoblastic cells from metal ion toxicity is supported by the chromium - induced elevations in hsp27 abundance and the behavior of the A7 cell line in response to metal ions in culture. Similar biochemical responses to altered cellular environments may contribute to the fate of tissues adjacent to select metallic implants.

• Proceedings of the KSAR Conference
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• 2003.06a
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• pp.22-22
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• 2003

This study was conducted to determine effects of polyvinyl alcohol (PVA), fetal bovine serum (FBS) and bovine serum albumin (BSA) on blastocoel formation, cell number, apoptosis and apoptosis-related gene expression of porcine diploid parthenotes developing in vitro. Embryos were collected from 2-cell or late 4-cell diploid parthenotes that activated with electro pulse, and in vitro cultured in the NCSU 23 medium supplemented without or with 0.1% PVA, 10% FBS or 0.4% BSA for day 7. The morphological analysis of apoptosis in embryos was carried out using propidium iodide staining and terminal deoxynucleotidyl transferase mediated dUTP nick end labeling. The expressions of Bcl-xL, Bak and P53 in blastocyst stage parthenotes and in vivo-derived blastocysts were determined using semiquantitative RT-PCR. The addition of 0.4% BSA to the culture medium enhanced the development of 2- or late 4-cell stage parthenotes to the blastocysts stage (P < 0.01) while FBS decreased the incidence of blastocoel formation. FBS also reduced cell numbers of blastocysts developed from both 2- (P < 0.001) and late 4-cell (P < 0.05) embryos and increased percentage of apoptosis in the blastocysts (P < 0.001). The relative abundance of Bcl-xL mRNA in diploid parthenotes cultured from 2-cell stage in the presence of BSA is similar with that in in vivo derived embryos, but is significantly higher than in parthenotes cultured with FBS, PVA or none protein supplement control. Bak mRNA showed a significant increase at the blastocyst stage in FBS supplement medium. This result suggests that apoptosis related gene expression is significantly affected by protein supplements, which may result in alteration of apoptosis and embryo viability of porcine embryos developing in vitro.

• Journal of the Korean Solar Energy Society
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• v.32 no.spc3
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• pp.194-198
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• 2012

Crystalline silicon solar cell remains the major player in the photovoltaic marketplace with 80% of the market, despite the development of various thin film technologies. Silicon's excellent efficiency, stability, material abundance and low toxicity have helped to maintain its position of dominance. However, the cost of silicon materials remains a major barrier to reducing the cost of silicon photovoltaics. Using the crystalline silicon wafer with thinner thickness is the promising way for cost and material reduction in the solar cell production. However, the thinner the silicon wafer is, the worse bow phenomenon is induced. The bow phenomenon is observed when two or more layers of materials with different temperature expansion coefficiencies are in contact, in this case silicon and aluminum. In this paper, the solar cells were fabricated with different thicknesses of Al layer in order to reduce the bow phenomenon. With less amount of paste applications, we observed that the bow could be reduced by up to 40% of the largest value with 120 micron thickness of the wafer even though the conversion efficiency decrease by 0.5% occurred. Since the bowed wafers lead to unacceptable yield losses during the module construction, the reduction of bow is indispensable on thin crystalline silicon solar cell. In this work, we have studied on the counterbalance between the bow and conversion efficiency and also suggest the formation of enough back surface field (BSF) with thinner Al layer application.

• ALGAE
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• v.21 no.3
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• pp.323-332
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• 2006

Mitochondrial distribution and abundance were assessed during the growth of apical and subapical cells in the red algae Colaconema caespitosum (J. Agardh) Jackelman, Stegenga and Bolton and Antithamnion cruciatum (C. Agardh) Nägeli after staining with 3,3’-dihexyloxacarbocyanine iodide [DiOC6(3)] and 2,4’-dimethylaminostyryl-Nethylpyridinium iodide (DASPEI). In fully elongate apical cells of C. caespitosum there were 100-120 mitochondria. During apical cell enlargement and division there is a doubling and then halving of the mitochondrial numbers. Apical cells prior to cytokinesis in young filaments are smaller than in mature filaments (ca. 50 and 100 μm long, respectively) and have fewer mitochondria (ca. 100 and 120 mitochondria per cell, respectively). In older vegetative cells mitochondria tend to aggregate at opposite ends of the cells with some mitochondria associated with the central nucleus or at points of apparent branch initiation. There is a greater density of mitochondria in apical cells of smaller versus larger plants (one mitochondrion per 6.3 μm3 and 9.8 μm3, respectively), suggesting that apical cells of younger plants may be more metabolically active. Male and female gametophytic thalli of Antithamnion cruciatum had similar numbers of mitochondria in apical cells of indeterminate axes, as did gametophytic and sporophytic thalli. There were about 40-50 mitochondria in fully elongated apical cells with about half this number in newly divided apical and subapical cells. Apical cells of determinate branches had more mitochondria (60-77) than indeterminate branches (60-70 vs. 40-50). In both species and in all cell types mitochondrial numbers were highly correlated with cell size.

• 한국해양학회지
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• v.26 no.1
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• pp.24-37
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• 1991

Marine benthic diatoms and environmental factors were studied at 60 sites on the Mangyung-Dongjin tidal flat of the west coast of Korea. Sediment samples were taken quantitatively from the upper 5 mm layer to obtain a representative estimate of the epipelic and epipsammic cell concentration. Surface sediments taken simultaneously with the quantitative diatom samples were analysed for the grain size. Exposure duration of study sites were calculated by the tide data recorded at Kunsan Outer-Harbour. Coarse sediments dominated mainly on the offshore coastal and lower tidal flat, whereas fine sediments occurred on inner and higher tidal flat. Total 371 diatom taxa were collected and the genera represented by a great number were Navicula and Nizschia. The 16 abundant species occupying more than 1% of total cell number are of the following: Paralia sulcata, Navicula sp. 1, Navicula arenaria, Cymatosira belgica, Amplora holsatica, Amphora coffeaeformis, Achnanthes hauckiana, Rhaphoneis amphiceros, Thalassionema nitzschioides. Navicula sp. 2, Dimeregramma minor, Amphora sp. 1, Cyclotella atomus, C, striata, Nitzschia kuetzingiana, Stephanodiscus sp. 1. The distribution pattern of these dominant species are described in relation to the habitat condition. Most of these species showed high densities in fine sediments. However, they occurred even silty sand and sandy sediments in low abundance. The epipsammic forms belonging to the Araphidineae and Monoraphidineae were restricted on the lower tidal flat. The typical species found in coarse sediments were: Cocconeis sp. 1, Opephora martyi, Amphora sabyii, Dimeregramma minor var. nana, Fragilaria virescens var. oblongella, F. virescens, Cocconeis grata. The higher tidal flat consisting of fine sediments showed relatively higher cell numbers than the lower tidal flat. River mouth region was the highest in abundance.

• Korean Journal of Materials Research
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• v.16 no.3
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• pp.193-197
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• 2006

The sodium/sulfur(Na/S) battery has many advantages such as high theoretical specific energy(760Wh/kg), and low material cost based on the abundance of electrode material in the earth. It has been reported that the electrochemical properties of sodium/sulfur cell above $300^{\circ}C$, utilized a solid ceramic electrolyte and liquid sodium and sulfur electrodes. A lot of researches have been performed in this field. Recently, Na/S battery system was applied for electricity storage system for load-leveling. One of severe problems of sodium/sulfur battery was high operating temperature above $300^{\circ}C$, which could induce the explosion and corrosion by molten sodium, sulfur and polysulfides. In order to develop sodium battery operated at low temperature, sodium ion battery has been studied using carbon anode, and sodium oxides cathodes. However, the energy densities of the sodium ion batteries were much lower than high temperature sodium/sulfur cell. In this study, the sodium/sulfur battery with 1M $NaCF_3SO_3$ is tested at room temperature. The charge-discharge mechanism was discussed based on XRD, DSC, SEM and EDS results.

• Clinical and Experimental Pediatrics
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• v.53 no.11
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• pp.921-930
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• 2010

Juvenile rheumatoid arthritis (JRA) is the most common rheumatic childhood disease; its onset is before 16 years of age and it persists for at least 6 weeks. JRA encompasses a heterogeneous group of diseases that is classified according to 3 major presentations: oligoarthritis, polyarthritis, and systemic onset diseases. These presentations may originate from the same or different causes that involve interaction with specific immunogenetic predispositions, and result in heterogeneous clinical manifestations. An arthritic joint exhibits cardinal signs of joint inflammation, such as swelling, pain, heat, and loss of function; any joint can be arthritic, but large joints are more frequently affected. Extra-articular manifestations include high fever, skin rash, serositis, and uveitis. The first 2 types of JRA are regarded as T helper 1 (Th1) cell-mediated inflammatory disorders, mainly based on the abundance of activated Th1 cells in the inflamed synovium and the pathogenetic role of proinflammatory cytokines that are mainly produced by Th1 cell-stimulated monocytes. In contrast, the pathogenesis of systemic onset disease differs from that of other types of JRA in several respects, including the lack of association with human leukocyte antigen type and the absence of autoantibodies or autoreactive T cells. Although the precise mechanism that leads to JRA remains unclear, proinflammatory cytokines are thought to be responsible for at least part of the clinical symptoms in all JRA types. The effectiveness of biologic therapy in blocking the action of these cytokines in JRA patients provides strong evidence that they play a fundamental role in JRA inflammation.