• Parasites, Hosts and Diseases
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• v.54 no.2
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• pp.147-154
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• 2016

Toxoplasma gondii infection induces alteration of the host cell cycle and cell proliferation. These changes are not only seen in directly invaded host cells but also in neighboring cells. We tried to identify whether this alteration can be mediated by exosomes secreted by T. gondii-infected host cells. L6 cells, a rat myoblast cell line, and RH strain of T. gondii were selected for this study. L6 cells were infected with or without T. gondii to isolate exosomes. The cellular growth patterns were identified by cell counting with trypan blue under confocal microscopy, and cell cycle changes were investigated by flow cytometry. L6 cells infected with T. gondii showed decreased proliferation compared to uninfected L6 cells and revealed a tendency to stay at S or G2/M cell phase. The treatment of exosomes isolated from T. gondii-infected cells showed attenuation of cell proliferation and slight enhancement of S phase in L6 cells. The cell cycle alteration was not as obvious as reduction of the cell proliferation by the exosome treatment. These changes were transient and disappeared at 48 hr after the exosome treatment. Microarray analysis and web-based tools indicated that various exosomal miRNAs were crucial for the regulation of target genes related to cell proliferation. Collectively, our study demonstrated that the exosomes originating from T. gondii could change the host cell proliferation and alter the host cell cycle.

• Journal of Plant Biotechnology
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• v.4 no.3
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• pp.123-127
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• 2002

Herbicide tolerant rice (Oryza sativa L. cv. Ilpumbyeo) cell lines were selected from $\gamma$-ray-irradiated anther-derived cell cultures. The anther-derived cell clusters were small (300 to 400 ${\mu}{\textrm}{m}$ in diameter) and uniform ones that were screened by miracloth filtering. The cell suspensions were very efficient to plate one layer onto agar medium and to screen target cell lines. Herbicide tolerant cell lines were selected by 5 mg/L cyhalofop butyl (CHB) treatment by using the small cell suspensions on agar N6 medium containing 1 mg/L 2,4-D and 0.2 mg/L kinetin. Of the cell lines, one line (CHB-1) showed stable tolerance at 10 mg/L concentration after 6-month culture without herbicide suspension. Growth stability of CHB-1 was similar to that of control cell line on 10 mg/L CHB containing medium. In this experiment we established herbicide tolerant cell line selection system by using anther-derived uniform-cell suspensions with $\gamma$-ray-irradiation.

• KSBB Journal
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• v.6 no.4
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• pp.395-402
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• 1991

A new process was developed to degrade PVA(polyvinyl alcohol) in desize wastewater. Two symbiotic bacteria of Pseudomonas strain G5Y and PW were immobilized on the media by adsorption. A natural zeolite was chosen as the best media considering cell adhesion capacity, sedimentation rate, and material cost. PVA and COD removal efficiencies of this system for synthetic wastewater were 84% and 85% at the retention time of 6 hr, when the volumetric loading rate was PVA 8g/L·day and COD 8g/L·day, and cell density was 19,775 mg/L. In case of desire wastewater, they were 78% and 72% at the retention time of 6 hr, respectively, when the volumetric loading rate was PVA 8g/L·day and COD 13.2g/L·day, and cell density was 32,899mg/L. In case of desize wastewater, PVA and COD removal efficiencies were lower than synthetic wastewater, but cell density of the desize wastewater was lower than that of the synthetic wastewater, because there were insufficiency of necessary nutrition and variety of desize materials in the desize wastewater. A pilot test was successfully performed showing 88% and 82%, PVA and COD removal efficiencies at the retention time of 24 hr, when volumetric loading rate were 4.7 PVA g/L·day and COD 6.9g/L·day, and cell density was 12,,324 mg/L.

• Microbiology and Biotechnology Letters
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• v.21 no.5
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• pp.421-427
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• 1993

Some interleukin 6 (IL-60 transcription control factors were resported as the regulator of IL-6 expression. A nuclear protein bound to interleukin 1 (IL-1) responsive element in the IL-6 promoter region was named NF-IL6 (nuclear factor for IL-6). This NF-IL6 was known to be very imporant as a transcription factor for various immuno-protein as well as for IL-6. The human NF-IL6 genes were transfected into the mouse L cells under the metallothionein promoter (MT promoter) to establish a model system for the expression of foreign gene in the mammalian cell line.

• Journal of Plant Biotechnology
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• v.29 no.2
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• pp.93-98
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• 2002

A VP6 fragments was subcloned with BamHI in the binary pMBP-1 vector under Califlower Mosaic Virus (CaMV) 355 promoter and neomycin phosphotransferase II (npt II) gene. The recombinant binary vector was mobilized into Agrobacterium-tumefaciens LBA4404 by the freeze-thaw method and potato (Solanum tubensum L. cv Desiree) was transformed by modified leaf-disc cocultivation. Shoots were induced on MS medium with 0.01 mg/L NAA, 0.1 mg/L GA$_3$, 2.0 mg/L Zeatin, 100.0 mg/L kanamycin, 500.0 mg/L carbenicillin. In order to identify the copy number of VP6 into potato plant, total genomic DNA was isolated from transgenic potato and analysed by Southern blotting. Genomic DNA and total mRNA analysis demonstrated the incorporation of the foreign gene into the potato genome, as well as their transcription.

• Journal of Plant Biology
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• v.29 no.3
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• pp.167-173
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• 1986

The effects of varying concentrations and durations of butachlor [N-(bytoxymethyl)-2-chlor-2', 6';-diethylacetanilide] treatment on oat (Avena sativa L.) root cell division were studied. Oats were treated from 0 to 48h with concentration ranging from 1$\times$10-6M to 1$\times$10-3M of butachlor. The highest concentration (1$\times$10-3M) of butachlor caused significant inhibition of cell division after 6h treatment. After 18h treatment, 49% and 66% inhibition of cell division occurred at 1$\times$10-5M and 1$\times$10-4M, respectively, while 16% inhibition of cell division occurred at 1$\times$10-6M concentration at same exposure period. Oat treated with 1$\times$10-5M and 1$\times$10-6M showed 69% and 38% inhibition of cell division after 36h. Increasing herbicide concentration at a specific time increased inhibition of cell division, and increasing the duration of treatment at a specific concentration also increased inhibition of cell division. In most instances the greatest inhibition of cell division occurred between 0 to 18h during 48h treatment. A range of concentration of 1$\times$10-5M to 1$\times$10-3M reduced cell enlargement significantly during 24h incubation period. The 1$\times$10-5M and 1$\times$10-3M caused 34% and 75% inhibition of cell enlargement. It was concluded that butachlor caused the growth inhibition of oats by inhibiting both cell division and cell enlargement.

• KSBB Journal
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• v.14 no.4
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• pp.445-451
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• 1999

Glutathione production was carried out using mixed cells of E. coli TG1/pDG7 $\alpha$ and bakers yeast in an Aerated Slurry Bioreactor. Glutathione-producing enzymes were stable for 34 hours, yielding 4.6 mM glutathione in suspension reaction. Glutahione production with high density mixed cells was studied as a function of flow rate in an Aereated Slurry Bioreactor. Glutathione concentration was higher than that in suspension reaction for 32 hours at the substrate feeding rate of 5.2 mL/hr with cell recycle in continuous Aerated Slurry Bioreactor. It was for 42 hours at 2.6 mL/hr and 22 hours at 5.2 mL/hr without cell recycle. Glutahione productivity was 25.7 mg/g wet $cell{\cdot}hr$ at the substrate feeding rate of 10.4 mL/hr with cell recycle, but 5.28 mg/g wet $cell{\cdot}hr$ at 5.2 mL/hr and 1.65 mg/g wet $cell{\cdot}hr$ at 2.6 mL/hr without cell recycle. Effective production time increased from 25 to 45 hours, by using a surfactant, tween 80. As a purfing gas, nitrogen was tested instead of air to avoid a possible oxidizing effect on glutathione-producing enzymes, resulting in the increase of effective production time to 40 hours.

• 한국생물공학회:학술대회논문집
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• 2000.11a
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• pp.301-304
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• 2000

Fed-batch culture was designed to increase cell concentration and astaxanthin content by mutant AJ-6 of Phaffia rhodozyma. Fed-batch culture was performed in the continuous feeding with manual adjustment of flow rate to control glucose concentration. When the final glucose concentration was 100 g/L, the cell and astaxanthin were 38.3 g/L, 34.8 mg/L, respectively. Addition of ethanol(10 g/L), when glucose was depleted, the cell and astaxanthin concentration were 37.2 g/L and 45.6, respectively, 5 g/L of acetic acid supplied, 40.6 g/L, 43.9 mg/L were obtained. Ethanol and acetic acid enhanced the astaxanthin content act as precursor of carotenoid synthesis.

• Journal of Animal Science and Technology
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• v.54 no.2
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• pp.103-109
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• 2012

Present study was performed to investigate the effect of single and co-culture of adipocyte and muscle cell lines on cell differentiation. 3T3-L1 (adipocyte) and L6 (muscle) cell lines were single-cultured on the condition of 10% fetal bovine serum (FBS)/Dulbeco's modified eagle's medium (DMEM) for 48 h followed by culture within 5% FBS/DMEM as a growth media. Then, the growth media was replaced by differentiation media composed of 2% FBS/DMEM without additives in single- or co-culture of the 3T3-L1 and the L6 cells to induce differentiation of both cell types. In co-culture system, the 3T3-L1 and the L6 cells were grown in separated places by being seeded on a $0.4{\mu}m$ insert membrane and on the bottom of 6 well plate, respectively. Cell differentiation was measured using morphological investigation and cytosolic analysis of glycerol-3-phosphate dehydrogenase (GPDH; for 3T3-L1) and creatine kinase (CK; for L6). Based on the GPDH results, the presence of L6 cells did not stimulate 3T3-L1 differentiation showing more differentiation of 3T3-L1 cells in the single-culture compared to the co-culture condition. In contrast, 3T3-L1 cells in the co-culture promoted differentiation of L6 cells. Enzymatic analysis supported this result showing that 3T3-L1 cells showed statistically (P<0.05) higher GPDH activity in the single-culture than the co-culture, whereas CK results of L6 cells were vice versa (P<0.05). Overall, present results may indicate that co-culture system is more reliable and precise technique compared to single-culture. Further studies on several co-culture trials including different media conditions, supplementation of differentiating substances, molecular biological analysis, etc. should be required to obtain practical and fundamental mass data.

• Animal cells and systems
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• v.11 no.1
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• pp.17-22
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• 2007

The effects of antimetabolite 6-AN (6-amino-nicotinamide) on viability and morphology of L6 myoblast cells have been investigated. 6-AN ($100{\mu}M$) induced a time-dependent decrease in cell viability with respect to the untreated control cells. Following 6-AN administration the viability rate started to decline sharply, reaching about 23% of the untreated control cells at 48 h. Inverted phase-contrast microscopy revealed that 6-AN caused characteristic morphological changes such as irregularly elongated and stellate shape of cells, round-shaped nucleus, cytoplasmic vacuolization, irregular cell arrangements and formation of large spaces among cell clusters. The concentrations of ATP and $NAD^{+}$ in the 6-AN treated cells were significantly lower (p < 0.01) than those of the untreated control cells. In contrast, the concentration of AMP was significantly increased by the 6-AN treatment. Activities of catalase, superoxide dismutase and glutathione peroxidase in 6-AN treated cells were significantly higher (p < 0.01) than those of the untreated control cells. The activities of glyceraldehyde-3-phosphate dehydrogenase in 6-AN treated cells were significantly lower (p < 0.01) than those of the untreated control cells. The results suggest that 6-AN caused marked reduction of cell viability and alterations of some important metabolites and enzymes.