• BMB Reports
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• v.29 no.3
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• pp.200-204
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• 1996

Nerve growth factor (NGF) is literally known to promote neural differentiation and survival in several peripheral and central neurons. Thus, it is Widely believed that NGF may serve as a therapeutic agent for many types of neuronal diseases. One of the mechanisms suggested to explain the protective role of NGF is that the trophic factor can prevent the increase of intracellular calcium ions which might be responsible for neural death. To examine whether or not the calcium hypothesis works even under pathological conditions, we applied NGF to cultures deprived of glucose. Surprisingly, what was observed here is that NGF rather promoted cell death under a glucose-deprived condition. What we call the NGF paradox phenomenon occurred in a calcium concentration-dependent manner, indirectly suggesting that NGF might increase intracellular calcium ions in cells deprived of glucose. This suggestion is further supported by the fact that nifedipine, a well-known L-type calcium channel blocker, could block the cell death potentiated by NGF. Here it is still premature to propose the complete mechanism underlying the NGF paradox phenomenon. However, this study certainly indicates that NGF as a therapeutic agent for neuronal diseases should be carefully considered before use.

• Korean Journal of Agricultural Science
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• v.3 no.2
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• pp.225-234
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• 1976

To elucidate ${\beta}$-glucosidase formation on various carbon scurces by cellulolytic bact-eia, Cellulomonas sp. CS1-1, the strain was grown on Nutrient Yeast Broth, carboxymethyl cellulose, avicel and cellobiose using a Ouickfit FVIL fermentor operated in batch, and the growth characteristics on those substrates and ${\beta}$-glucosidase distribution of extra and intracellular enzyme components were studied. The results were: 1) ${\beta}$-glucosidase was always intracellular, and was formed under all growth conditions tested, ii) but levels of relative activities were higher when the culture was grown on cellobiose and on avicel, iii) the relative activities were always maximum during the growth phase of the organism irrespective of the substrate used.

• Biomolecules & Therapeutics
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• v.19 no.4
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• pp.487-492
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• 2011

In our previous study, we investigated Chenopodium album Linne (CAL) ethanol extract and its fractions on anti-gastritic actions using the HCl/ethanol and indomethacin induced gastric lesion model and Helicobacter pylori (H. pylori). Based on the results, butanol fraction was most effective among fractions obtained from CAL. This study aims to elucidate the mechanisms of butanol fraction, and betaine as a constituent of the butanol fraction, on gastritis and anti-gastric cancer cell growth. First, we examined antioxidant properties using hydrogen peroxide and superoxide radical, and we found that butanol fraction and betaine may be good antioxidants. Second, cytotoxicity was assessed by measuring cell viability and 4,6-diamidino-2-phenylinodole dihydrochloride (DAPI) staining of human gastric cancer cells (AGS cells). We also examined the relationship between the cytotoxicity and intracellular $Ca^{2+}$ signaling mechanism. The butanol fraction demonstrated cell viability 71.49% at the concentration of 100 ${\mu}g/ml$ and increased intracellular $Ca^{2+}$ concentration in a dose dependent manner. Finally, we observed the mucus content as a defensive factor and gastric secretion as an aggressive factor, and found that the mucus content noticeably increased when treated with butanol fraction and betaine and gastric secretion decreased when treated with betaine in vivo study. From these results, we suggest that CAL butanol fraction and betaine may have protective effects on gastritis.

• Journal of Pharmaceutical Investigation
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• v.38 no.3
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• pp.163-169
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• 2008

Liposomes are spherical vesicles composed of lipid bilayer membranes. However, the conventional liposomes have been found to be plagued by rapid opsonization and taken up by the reticuloendothelial system (RES), resulting in shortened circulation time and limited intracellular uptake to target cell. In this study, polyethyleneglycol-cationic liposomes (PCL) containing cationic lipid and DSPE-mPEG were prepared by thin film cast-hydration method. The PEG liposomes had approximately $97.0{\pm}1.3\;nm$ of mean particle diameter and $-21.7{\pm}1.2\;mV$ of zeta potential value. PCL had $96.4{\pm}1.8\;nm$ of mean particle diameter and $-8.7{\pm}1.1\;mV$ of zeta potential value with a decrease of about 10 mV compared to the PEG liposomes. Loading of model drug, doxorubicin (DOX), in liposomes were carried out by using remote loading method and the loading efficiency of DOX in liposomes was about $95.0{\pm}1.9%$. Intracellular uptake and cytotoxicity of PCL were higher than that of PEG liposomes to murine B16F10 melanoma cells. In addition, anti-tumor activity of PCL was similar to that of PEG liposomes on growth of A549 human lung carcinoma in BALB/c mice. Consequently, PCL modified with cationic lipid may be applicable as anticancer drug carriers that can increase intracellular uptake and therapeutic efficacy.

• Journal of Marine Bioscience and Biotechnology
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• v.6 no.2
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• pp.110-117
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• 2014

Recently microalgae have been proposed as a promising biodiesel feedstock, owing to their higher lipid productivity and non-arable land based cultivation system. Biomass and lipid productivities of microalgae are largely affected by various environmental and nutritional factors. In this study, the effects of nitrogen (nitrate and ammonium) and organic carbon (glucose and glycerol) sources on the cell growth and lipid production of Chlorella sp. KR-1 were examined in flask cultures. Under autotrophic culture conditions for 15 days, overall cell growth and lipid (fatty acid methyl ester, FAME) production with nitrate were better than those of ammonium, resulting in 1.06 g cell/L and 333 mg FAME/L, respectively. Maximal intracellular lipid contents (348 - 352 mg FAME/g cell) were observed at low concentrations of 1 mM for both nitrate and ammonium. In the supply of light, addition of glucose in the range of 1 - 20 g/L showed higher cell densities than the autotrophic cell growth condition. Higher lipid accumulation of 375 mg FAME/g cell could achieved at 5 g glucose/L albeit of relatively short incubation of 7 days. With glycerol, intracellular lipid contents were ~1.9 times lower than glucose cases although similar cell growths were observed for both carbon sources.

• Food Science and Biotechnology
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• v.16 no.4
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• pp.580-583
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• 2007

Phytase activity was examined with various bifidobacterial strains cultured statically in MRS broth at $37^{\circ}C$ for 48 hr. Seven Bifidobacterium species showed mostly an intracellular phytase activity, though their specific activities were very low. The highest specific activity was found in Bifidobacterium animalis B33 strain, among 7 bifidobacteria tested. The specific activity was highest during the exponential growth phase. Carbohydrates and the concentration of phosphorus sources had an effect on the phytase activity and bacterial growth. Glucose was the most favorable carbohydrate for the phytase activity. Phytate inhibited the cell growth, and phytase activity decreased with increase of phytate concentration. The phytase activity was even higher in the static microaerophilic growth than that in anaerobic state, despite the stimulated growth in anaerobic growth. The optimal pH ranges were comparatively broad, but the optimal temperatures were $50^{\circ}C$ for all tested strains. The phytase activity was most active at pH 6.5 and $50^{\circ}C$ for B. animalis B33 strain.

• Journal of Microbiology and Biotechnology
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• v.11 no.4
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• pp.552-557
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• 2001

By UV-irradiation of Eremothecium ashbyii DTl, a higWy flavinogenic mutant (UV-18-57) and a nonflavinogenic mutant (UV -85) were obtained. The physio-morphological characteristics of these three strains were studied on glucose medium in submerged fermentation. Glucose utilization and mycelial growth occurred in 0 - 2 days of fermentation. By the third day, the biomass had declined. Extracellular riboflavin excretion was distinct from the second day, reaching a maximum rate by the fourth day. The hyphae of the highly flavinogenic mutant UV-18-57 were broader than DTl, while the nonflavinogenic UV-85 hyphae were very thin. Riboflavin accumulation was high in UV-18-57 (extracellular riboflavin,$825\mu\textrm{g}/ml$ , and intracellular, $490\mu\textrm{g}/ml$) and caused the mycelia to swell into bulbous forms. Riboflavin accumulation was less in DTl ($108\mu\textrm{g}/ml$ extracellular and $24\mu\textrm{g}/ml$ intracellular) and correspondingly its hyphae were thinner than those of UV-18-57 and swollen bulbous mycelia were not prominent. UV-85 was nonflavinogenic and, accordingly, its mOlphological characteristics included long thin filaments with no intracellular riboflavin accumulation. A large number of greenish fluorescence spores were seen in UV-18-57, whereas DTI had less spores and UV-85 was nonsporulating. Sporulation is correlated with riboflavin production. UV-18-57 had better mycelial integrity and lysis started only by the seventh day, whereas DTI and UV -85 started to lyze earlier by 4 -5 days. By the late stage of fermentation (eighth day), DTl had a few long, thin filaments indicating some secondary growth, whereas UV -85 showed a compact pellet form of mycelia. Most mycelia of UV-18-57 still appeared intact.

• Journal of Microbiology and Biotechnology
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• v.26 no.3
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• pp.503-510
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• 2016

The accumulation (internal and superficial distribution) of magnesium ions (Mg²⁺) by the green freshwater microalga Chlorella vulgaris (C. vulgaris) was investigated under autotrophic culture in a stirred photobioreactor. The concentrations of the three forms of Mg²⁺ (dissolved, extracellular, and intracellular) were determined with atomic absorption spectroscopy during the course of C. vulgaris growth. The proportions of adsorbed (extracellular) and absorbed (intracellular) Mg²⁺ were quantified. The concentration of the most important pigment in algal cells, chlorophyll a, increased over time in proportion to the increase in the biomass concentration, indicating a constant chlorophyll/biomass ratio during the linear growth phase. The mean-average rate of Mg²⁺ uptake by C. vulgaris grown in a culture medium starting with 16 mg/l of Mg²⁺ concentration was measured. A clear relationship between the biomass concentration and the proportion of the Mg²⁺ removal from the medium was observed. Of the total Mg²⁺ present in the culture medium, 18% was adsorbed on the cell wall and 51% was absorbed by the biomass by the end of the experiment (765 h). Overall, 69% of the initial Mg²⁺ were found to be removed from the medium. This study supported the kinetic model based on a reversible first-order reaction for Mg²⁺ bioaccumulation in C. vulgaris, which was consistent with the experimental data.

• The Korea Journal of Herbology
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• v.31 no.1
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• pp.61-67
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• 2016

Objectives : The present study aimed to investigate the anti-inflammatory effects of the water extracts of Portulacae Herba (PH).Methods : We measured the effects of the water extracts of Portulacae Herba (PH) on the cell viability of mouse macrophage RAW 264.7 cells, the intracellular calcium production, and the proinflammatory mediators including nitric oxide (NO), vascular endothelial growth factor (VEGF), platelet-derived growth factor (PDGF)-BB, which are induced by the lipopolysaccharides (LPS), and obtained the results shown below.Results : After the cultivation of the PH extracts along with the mouse macrophages, the cell survival rate did not decrease with the MTT assay. However, the PH extracts did significantly suppress the production of NO by the mouse macrophages induced by LPS at the concentrations of 25, 50 and 100 ㎍/mL. The PH extract also significantly suppressed the VEGF, PDGF-BB and intracellular calcium production of the mouse macrophages by LPS at concentrations of 25, 50 and 100 ㎍/mL. As shown in the results above, the PH extracts do not have a toxic effect on the macrophages, but still have an anti-inflammatory effect that significantly reduces the intracellular calcium production as well as the production of NO, VEGF and PDGF-BB at concentrations above 25 ㎍/mL.Conclusions : In conclusion, the inhibitory anti-inflammatory effects of the PH extract can be used for a new treatment of anti-inflammatory diseases.

• Journal of Microbiology and Biotechnology
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• v.30 no.4
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• pp.482-489
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• 2020

We previously identified β-sitosterol (BS) as one of the most abundant compounds found in Korean red ginseng oil. BS is a widely prevalent vegetable-derived phytosterol with many known health benefits. Here, we investigated the efficacy of BS against Brucella (B.) abortus infection. BS showed no effect on bacterial growth but attenuated internalization, intracellular survival and MAPKs-linked intracellular signaling in RAW264.7 cells. BS treatment in cells is also associated with increased nitrite concentration during infection at 24 h. Slightly enhanced resistance to B. abortus infection was observed in mice orally given BS, which could be mediated by induced production of proinflammatory cytokines. Taken together, our study demonstrates the contribution of BS treatment against B. abortus infection although further investigation is encouraged to maximize its beneficial effects against intracellular infection.