• Journal of Life Science
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• v.25 no.2
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• pp.189-196
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• 2015

Bacterial diversity was studied in the rhizosphere of Suaeda japonica Makino, which is native to Suncheon Bay in South Korea. Soil samples from several sites were diluted serially, and pure isolation was performed by subculture using marine agar and tryptic soy agar media. Genomic DNA was extracted from 29 pure, isolated bacterial strains, after which their 16S rDNA sequences were amplified and analyzed. Phylogenetic analysis was performed to confirm their genetic relationship. The 29 bacterial strains were classified into five groups: phylum Firmicutes (44.8%), Gamma proteobacteria group (27.6%), Alpha proteobacteria group (10.3%), phylum Bacteriodetes (10.3%), and phylum Actinobacteria (6.8%). The most widely distributed genera were Bacillus (phylum Firmicutes), and Marinobacterium, Halomonas, and Vibrio (Gamma proteobacteria group). To confirm the bacterial diversity in rhizospheres of S. japonica, the diversity index was used at the genus level. The results show that bacterial diversity differed at each of the sampling sites. These 29 bacterial strains are thought to play a major role in material cycling at Suncheon Bay, in overcoming the sea/mud flat-specific environmental stress. Furthermore, some strains are assumed to be involved in a positive interaction with the halophyte S. japonica, as rhizospheric flora, with induction of growth promotion and plant defense mechanism.

• The Korean Journal of Physiology and Pharmacology
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• v.17 no.3
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• pp.203-208
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• 2013

As the abnormal proliferation of vascular smooth muscle cells (VSMCs) plays a critical role in the development of atherosclerosis and vascular restenosis, a candidate drug with antiproliferative properties is needed. We investigated the antiproliferative action and underlying mechanism of a newly synthesized naphthoquinone derivative, 5,8-dimethoxy-2-nonylamino-naphthalene-1,4-dione (2-nonylamino-DMNQ), using VSMCs treated with platelet-derived growth factor (PDGF). 2-Nonylamino-DMNQ inhibited proliferation and cell number of VSMCs induced by PDGF, but not epidermal growth factor (EGF), in a concentration-dependent manner without any cytotoxicity. This derivative suppressed PDGF-induced $[^3H]$-thymidine incorporation, cell cycle progression from $G_0/G_1$ to S phase, and the phosphorylation of phosphor-retinoblastoma protein (pRb) as well as the expression of cyclin E/D, cyclin-dependent kinase (CDK) 2/4, and proliferating cell nuclear antigen (PCNA). Importantly, 2-nonylamino-DMNQ inhibited the phosphorylation of PDGF receptor${\beta}$(PDGF-$R{\beta}$) enhanced by PDGF at $Tyr^{579}$, $Tyr^{716}$, $Tyr^{751}$, and $Tyr^{1021}$ residues. Subsequently, 2-nonylamino-DMNQ inhibited PDGF-induced phosphorylation of STAT3, ERK1/2, Akt, and $PLC{\gamma}1$. Therefore, our results indicate that 2-nonylamino-DMNQ inhibits PDGF-induced VSMC proliferation by blocking PDGF-$R{\beta}$ autophosphorylation, and subsequently PDGF-$R{\beta}$-mediated downstream signaling pathways.

• The Korean Journal of Ecology
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• v.26 no.3
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• pp.109-114
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• 2003

To investigate ecophysiological characteristics of plants species adapted to moor habitat, we selected 22 species plants and analyzed inorganic cations (K, Ca, Mg), heavy metals (Al, Fe, Mn) and total nitrogen and phosphorus quantitatively. Moojechi moor indicated typical acidic and oligotrophic conditions with pH of 5.0∼5.6 (pH 4.3∼5.1 in soil) and EC of 15∼30μ S/cm, and contained very low contents of soil divalent cation such as Ca and Mg but high contents of heavy metals (esp. Al). With respect to inorganic cation contents, investigated plants species showed remarkable interspecific difference. Plant species belonging to J. effusus var. decipiens, M. japonica, I. globosa, M. sacchariflorus, R. mucronulatum, R. yedoense var. poukhanense, H. micrantha, D. rotundifolia showed very low contents of inorganic cation below 400 μ M/g DW, but plant species of C. palustris var. spontanea, L. sessilifolia, P. mandarinorum, C. lineare, S. austriaca sub. glabra, V. mandshurica, A. decursiva showed high cation contents in leaves. Especially, S. austriaca sub. glabra (Compositae) and V. mandshurica (Violaceae) showed pattern accumulating Ca and Mg with plant growth, but I. ensata var. spontanea (Iridaceae) and S. officinalis (Rosaceae) showed decreasing tendency. Meanwhile, most plant species showed low contents of soluble metal ions in leaves in spite of high heavy metal contents on soil, and indicated remarkable interspecific differences in the total contents and composition of heavy metals accumulated. Despite low contents of N and P on soil, most plant species indicated relatively high contents of N and P in leaves at the early stage of growth, and showed slowly decreasing pattern according to growth. Consequently, it seems that plant species inhabited on Moojechi moor cope with acidic-oligotrophic conditions, accumulating inorganic cations and nitrogen at the early growing stage and reutilizing them in the course of growth, and developing heavy metal excluding mechanism.

• Food Science and Industry
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• v.52 no.3
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• pp.261-271
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• 2019

Gut microbiome have recently provided evidence that the gut microbiota are capable of greatly influencing all aspects of physiology and immunology. Although a number of recent studies have shown that probiotics can modulate gut microbiota structure, the mechanism underlying this effect remains to be elucidated. In a disease state, the relative abundances of beneficial gut bacteria are generally reduced, which is restored by constant probiotic supplementation. Oral administration of probiotics improved the disease state by (1) inducing differentiation and function of regulatory T cells, (2) reducing inflammatory response, (3) modulating the gut environment, and (4) increasing the proportions of short-chain fatty acid- or beneficial metabolite-producing gut microbiota including the genera Bifidobacterium, Faecalibacterium, Akkermansia, etc. In this review, current knowledge on how probiotics can influence host's health by altering gut microbiota structure and on how probiotics and beneficial gut bacteria can be applied as next-generation probiotics will be discussed.

• Korean Journal of Pharmacognosy
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• v.52 no.1
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• pp.34-40
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• 2021

Proliferation and maintain of dermal papilla during progression of hair-cycle are crucial to the duration of anagen and regulated by diverse signaling pathway such as PI3K/Akt/Wnt/β-catenin pathway. In this study, we investigated the effects and mechanisms of Viola verecunda on dermal papilla cells. Treatment of dermal papilla cells with whole plant extract of V. verecunda resulted in cell proliferation, which was accompanied by up-regulation of cyclin D1, phospho (ser780)-pRB and cdc2 p34, and down-regulation of p27kip1. V. verecunda extract also promoted the levels of phospho (ser473)-Akt and phospho (ser780)-pRB in a time-dependent manner. Inhibition of PI3K/Akt by Wortmannin suppressed progression of cell-cycle, thereby attenuated the increases in proliferation of dermal papilla cells by V. verecunda extract. We further investigated Wnt/β-catenin pathway with respect to the effects of V. verecunda extract on the proliferation of dermal papilla cells. Treatment with V. verecunda extract results in up-regulation of Wnt/β-catenin proteins such as phospho (ser9)-GSKβ, phospho (ser552)-β-catenin and phospho (ser675)-β-catenin. In addition, Wortmannin abrogated V. verecunda extract mediated up-regulation of cdc2 p34 and down-regulation of p27kip1. These finding reveal that the proliferative effect of V. verecunda mediated by alteration of cell-cycle via activating PI3K/Akt/Wnt pathway in dermal papilla cells.

• The Korean Journal of Pharmacology
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• v.29 no.1
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• pp.97-105
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• 1993

Adenosine receptors in rat adipose tissues have been reported to be of $A_{1}$ subclass, and their stimulation leads to inhibition of adenylyl cyclase, resulting in inhibition of lipolysis. In the present study we investigated changes in $A_{1}$ adenosine receptor-adenylyl cyclase system of adipocytes following induction of experimental diabetes in rats. One week following experimental diabetes were induced by intravenous injection of streptozotocin (50 mg/kg body wt.), adipocytes from rats $(170{\sim}230g)$ fed ad libitum were isolated using collagenase. When adipocytes were incubated for 1 h with 1 unit/ml adenosine deaminase and $1\;{\mu}M$ isoproterenol, and assayed for glycerol formation, it was found that the inhibition of lipolysis in diabetic adipocytes by $(-)-N^{6}-(R-phenylisopropyl)adenosine$ (PIA), an $A_{1}$, adenosine receptor agonist, was twice that of control adipocytes. In an effort to delineate the mechanism(s), $[^{3}H]PIA$ binding to adipocytic membranes from diabetic and control rats were determined. Neither the affinities nor numbers of $A_{1}$ adenosine receptor were significantly different from each other (Best fit parameters for the one-site model are: $K_{d}=0.51{\pm}0.09nM$ and $B_{max}=1.60{\pm}0.12\;pmoles/mg$ protein for control membranes; $K_{d}=0.54{\pm}0.21\;nM$ and $B_{max}=1.72{\pm}0.31\;pmoles/mg$ protein for diabetic membranes). However, the inhibiton by PIA of the isoproterenol-stimulated adenylyl cyclase activities was found to be 1.9 times higher in adipocytic membranes from diabetic rats than those from controls. These results suggest that the increased sensitivity of inhibition of lipolysis to PIA in adipocytic membranes from diabetic rats is due to changes in signal transduction pathways, rather than alterations of $A_{1}4 adenosine receptor molecules themselves.

• Journal of the Korean Society for Marine Environment & Energy
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• v.15 no.2
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• pp.133-141
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• 2012

Effects of temperature and salinity on the growth of the toxic dinoflagellate $Alexandrium$ $tamarense$ and $A.$ $catenella$ isolated from the southern coast of Korea were examined in the laboratory. Growth experiment was conducted under the following combinations of temperature and salinity; 10, 15, 20, 25 and $30^{\circ}C$, 10, 15, 20, 25, 30 and 35 psu at a constant irradiance of 300 ${\mu}mol$ photons $m^{-2}s^{-1}$. Temperature and salinity conditions for maximum growth rate were indicated as follows: temperature $15^{\circ}C$ and salinity 30 psu (0.31 $d^{-1}$) in $A.$ $tamarense$, temperature $25^{\circ}C$ and salinity 30 psu (0.36 $d^{-1}$) in A. catenella. Temperature and salinity ranges for optimum growth condition of two species were $10{\sim}20^{\circ}C$, 25~35 psu and $120{\sim}30^{\circ}C$, 25~35 psu, respectively. The result of two-factor ANOVA indicated significant effects (P<0.001) of temperature and salinity on the growth rate, and two species were more effected by a temperature than a salinity on the growth. In addition, prediction equations were obtained through the multiple regressions of the specific growth rates as ${\mu}=0.04+0.0193T-0.0339S- 0.0005T^2+0.0021S^2+0.00073TS-0.000022T^3-0.000038S^3+0.00000086TS^2-0.0000255T^2S$ in $A.$ $tamarense$ and ${\mu}=1.01-0.1288T-0.0778S+0.0067T^2+0.0038S^2+0.00204TS-0.0001T^3-0.000059S^3-0.0000131TS^2-0.0000392T^2S$ in $A.$ $catenella$. Correlation coefficient between experimental values and simulated values was highly indicated. These results seem to provide information for understanding the spreading mechanism of $A.$ $tamarense$ and $A.$ $catenella$.

• Korean Chemical Engineering Research
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• v.47 no.5
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• pp.630-638
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• 2009

A computational fluid dynamics(CFD) model is developed and validated with on-site experiments for a urea-based SNCR(selective non-catalytic reduction) process to reduce the nitrogen oxides($NO_x$) in a municipal incinerator. The three-dimensional turbulent reacting flow CFD model having a seven global reaction mechanism under the condition of low CO concentration and 12% excess air and droplet evaporation is used for fluid dynamics simulation of the SNCR process installed in the incinerator. In this SNCR process, urea solution and atomizing air were injected into the secondary combustor, using one front nozzle and two side nozzles. The exit temperature($980^{\circ}C$) of simulation has the same value as in situ experiment one. The $NO_x$ reduction efficiencies of 57% and 59% are obtained from the experiment and CFD simulation, respectively at NSR=1.8(normalized stoichiometric ratio) for the equal flow rate ratio from the three nozzles. It is observed in the CFD simulations with varying the flowrate ratio of the three nozzles that the injection of a two times larger front nozzle flowrate than the side nozzle flowrate produces 8% higher $NO_x$ reduction efficiency than the injection of the equal ratio flowrate in each nozzle.

• The korean journal of orthodontics
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• v.31 no.2 s.85
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• pp.237-248
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• 2001

Biomechanical reactions of tooth movement are the combination of bone formation and resorption, in which many paracrine factors are involved. The sex hormone is one of the paracrine factors and the sex hormonal level of an adult female vanes according to the body condition, e.g. mensturation, pregnancy, postmenopause, etc. Although the exact mechanism is not clarified yet, estrogen and progesterone are known to regulate the function of osteoblast. Again osteoblast is reported to affect the function of osteoclast. The purpose of this study is to determine the influence of the female sex hormone, estrogen and progesterone, on the cell proliferation and activity of HOS and ROS17/2.8 cell line. The observed results were as follows. 1. Estrogen inhibited HOS cell proliferation and promoted ROS17/2.8 cell proliferation. 2. Estrogen increased the activity of alkaline phosphatase of HOS cell and reduced the activity of alkaline phosphatase of ROS17/2.8 cell. 3. Progesterone inhibited the proliferation of HOS and ROS17/2.8 cell, but had no influence on the activity of alkaline phosphatase. 4. Estrogen and progeterone did not have any particular effects on the activity of super oxide, nitric oxide and gelatinase of HOS and ROS17/2.8 cell.

• Journal of the Korean Society of Food Science and Nutrition
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• v.22 no.4
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• pp.405-411
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• 1993

Several studies have shown that phytol isolated from perilla leaf and small water dropwort (Oenanthe javanica (BL) D.C., wild type) extract reveal antirumor activities. In the present study we investigated the effect of phytol and the small water dropwort extract on the T subset in the sarcoma 180-transplanted mice in order to elucidate the immunological mechanism of antiturmor activity of these substances. The results obtained from the experiment were as follows : When phytol was injected into the sarcoma-180 transplanted mice (control), the levels of T cell and T subset by inoculation of the tumor cells were enhanced, but that of T cells in case of small water dropwort extract was similar to the control. Asialo GM1$^{＋}$ cells were increased when phytol or small water dropwort extract with injected into tumor-transplanted mice. In normal mice the number of asialo GM1$^{＋}$ cells increased with phytol injection and decreased with small water dropwort extract injection. L3T4$^{＋}$/Lyt-2$^{＋}$cell ratios were decreased when phytol was injected into tumor-transplanted mire, but increased in case of small water dropwort extract injection. In normal mice the ratios showed large decreases with phytol or small water dropwort extract injection. These results indicate that phytol or small water dropwort extract ran activate the proliferation of natural killer cells that are effector cells in tumor-bearing mice.