• KSBB Journal
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• v.14 no.4
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• pp.389-395
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• 1999

Bifidobcterium spp. can provide human being with several beneficial physiological. Therefor, there has been a considerable interest in products Bifidobcterium spp. dietary supplements or as starter cultures for probiotic products that may assint in the improvement of health on the human. But indusrial applications have been limited because Bifidobcterium spp. are sensitive to acidic pH due to organic acid produced by themselves and various conditions. The objective of this study was to establish new method for improvement of Bifidobcterium viability by entrapment im calcium alginate beads. We have a plan to select the most suitable polymer through the comparison with acid tolerance oxygen tolerance and theological properties of polymer. Increase of the viable number of Bifidobcterium induced increasing acid tolerance and oxygen tolernce trough the development of entrapment technique. The 4%, 3030mm diameter) sodium alginate beads led to the best survivability under acid condition. Especially, addition of 6% mannitol, 6% glycerol or 6% sorbitol to the sodium alginate helped a beneficial effect on viability against acid, bile salt, hydrogen peroxide and cold strage. The number of viability of entrapeede cells by retreatment was 96 fold higher than non-entrapeed cells after 5 hours of storage under pH 3 acidic condition. These experimental data clearly demonstrate that a whole cell immobilization by entrapment in calcium alginate beads is an important survival mechanism enable to withstand environmental stresses as the acidic condition, hydrogen peroxide toxicity and frozen state.

• Journal of Korean Academy of Oral and Maxillofacial Radiology
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• v.25 no.2
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• pp.331-341
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• 1995

The purpose of this study was to aid in the prediction of tumor cell tolerance to radiotherapy and/or chemotherapy. For this study, cell surviving curves were obtained for murine melanoma Bl6 cell line using semiautomated M1T assay. 2,4,6,8, 10Gy were irradiated at a dose rate of 210cGy/min using /sup 60/Co Irradiator ALOORADO 8. After irradiatior, B16 cell lines(2.5×10⁴ cells/ml) were exposed to bleomycin and cisplatin at concentration of 0.2㎍/㎖, 2㎍/㎖ and 20㎍/㎖ for I hour respectively. The viable cells were determined for each radiation dose and/or each concentration of drug. And they were compared to control values. The obtained results were as follows : 1. There was significant difference of surviving fraction at 4, 6, 8, 10Gy on B16 cell line(P<0.05). 2. There was significant difference of cytotoxicity between bleomycin and cisplatin at concentration of 0.2㎍/㎖ and 2㎍/㎖(P<0.05) on B16 cell line, but there was no significant difference of cytotoxicity at concentration of 20㎍/㎖ on B16 cell line. 3. There was significant difference of cytotoxicity of bleomycin after irradiation of 2Gy and 10Gy on B16 cell line(P<0.01). 4. There was significant difference of cytotoxicity of cisplatin at concentration of 20㎍/㎖ after irradiation on B16 cell line.

• Journal of Microbiology and Biotechnology
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• v.26 no.6
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• pp.1011-1017
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• 2016

The antimicrobial effects of methanol and ethanol extracts of Inula britannica against several Helicobacter pylori strains (26695, J99, and SS1) were evaluated in vitro, to determine their applicability as functional foods. In the paper disc diffusion method, the antimicrobial effects of the I. britannica extracts against the H. pylori strains were apparent. Viable cell counting also showed that the extracts at 100 μg/ml concentration dramatically decreased the viability of the H. pylori strains. In particular, the methanol and ethanol extracts at a concentration of 100 μg/ml reduced the H. pylori SS1 cell number to 2.46 log CFU/ml and 1.08 log CFU/ml, respectively. In the presence of 100 μg/ml extracts, the urease production of H. pylori SS1 was decreased to more than 30%, whereas that of H. pylori J99 and H. pylori 26695 was decreased to about 20%, relative to the controls. The extracts inhibited the attachment of the H. pylori strains to human gastric AGS cells as well as caused the detachment of already attached H. pylori cells. In addition, the H. pylori morphology was changed to a coccoidal shape in the presence of the extracts. In conclusion, the I. britannica extracts were effective against H. pylori strains in vitro, irrespective of genotype status, and could therefore be used as novel functional foods.

• Proceedings of the Korean Society of Developmental Biology Conference
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• 2003.10a
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• pp.29-48
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• 2003

It is remarkable that nuclear transfer using differentiated donor cells can produce physiologically normal cloned animals, but the process is inefficient and highly prone to epigenetic errors. Aberrant patterns of gene expression in clones contribute to the cumulative losses and abnormal phenotypes observed throughout development. Any long lasting effects from cloning, as revealed in some mouse studies, need to be comprehensively evaluated in cloned livestock. These issues raise animal welfare concerns that currently limit the acceptability and applicability of the technology. It is expected that improved reprogramming of the donor genome will increase cloning efficiencies realising a wide range of new agricultural and medical opportunities. Efficient cloning potentially enables rapid dissemination of elite genotypes from nucleus herds to commercial producers. Initial commercialization will, however, focus on producing small numbers of high value animals for natural breeding especially clones of progeny-tested sires, The continual advances in animal genomics towards the identification of genes that influence livestock production traits and human health increase the ability to genetically modify animals to enhance agricultural efficiency and produce superior quality food and biomedical products for niche markets. The potential opportunities in animal agriculture are more challenging than those in biomedicine as they require greater biological efficiency at reduced cost to be economically viable and because of the more difficult consumer acceptance issues. Nevertheless, cloning and transgenesis are being used together to increase the genetic merit of livestock; however, the integration of this technology into farming systems remains some distance in the future.

• Proceedings of the Korean Society of Embryo Transfer Conference
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• 2003.10a
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• pp.29-48
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• 2003

It is remarkable that nuclear transfer using differentiated donor cells can produce physiologically normal cloned animals, but the process is inefficient and highly prone to epigenetic errors. Aberrant patterns of gene expression in clones contribute to the cumulative losses and abnormal phenotypes observed throughout development. Any long lasting effects from cloning, as revealed in some mouse studies, need to be comprehensively evaluated in cloned livestock. These issues raise animal welfare concerns that currently limit the acceptability and applicability of the technology. It is expected that improved reprogramming of the donor genome will increase cloning efficiencies realising a wide range of new agricultural and medical opportunities. Efficient cloning potentially enables rapid dissemination of elite genotypes from nucleus herds to commercial producers. Initial commercialisation will, however, focus on producing small numbers of high value animals for natural breeding especially clones of progeny-tested sires. The continual advances in animal genomics towards the identification of genes that influence livestock production traits and human health increase the ability to genetically modify animals to enhance agricultural efficiency and produce superior quality food and biomedical products for niche markets. The potential opportunities inanimal agriculture are more challenging than those in biomedicine as they require greater biological efficiency at reduced cost to be economically viable and because of the more difficult consumer acceptance issues. Nevertheless, cloning and transgenesis are being used together to increase the genetic merit of livestock; however, the integration of this technology into farming systems remains some distance in the future.

• The Korean Journal of Physiology and Pharmacology
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• v.28 no.1
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• pp.31-38
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• 2024

As in type 1 diabetes, the loss of pancreatic β-cells leads to insulin deficiency and the subsequent development of hyperglycemia. Exercise has been proposed as a viable remedy for hyperglycemia. Lithium, which has been used as a treatment for bipolar disorder, has also been shown to improve glucose homeostasis under the conditions of obesity and type 2 diabetes by enhancing the effects of exercise on the skeletal muscles. In this study, we demonstrated that unlike in obesity and type 2 diabetic conditions, under the condition of insulin-deficient type 1 diabetes, lithium administration attenuated pancreatic a-cell mass without altering insulin-secreting β-cell mass, implying a selective impact on glucagon production. Additionally, we also documented that lithium downregulated the hepatic gluconeogenic program by decreasing G6Pase protein levels and upregulating AMPK activity. These findings suggest that lithium's effect on glucose metabolism in type 1 diabetes is mediated through a different mechanism than those associated with exercise-induced metabolic changes in the muscle. Therefore, our research presents the novel therapeutic potential of lithium in the treatment of type 1 diabetes, which can be utilized along with insulin and independently of exercise.

• KSBB Journal
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• v.7 no.2
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• pp.132-138
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• 1992

Sprial adaptation technique of conditioned media has been applied to cultivate human cell line which can not survive in a serum free mdium without adding any growth factors in basal medium Doubling time and scu-PA production from serum free adapted cells were 5 days and 890 (IU/mL), respectively in a T-flask, whose values were not much lower than the productivity of 1100(IU/mL) from 5% serum containing medium. It was required to use conditioned media for attaching cells on microcarriers when cells were inoculated into a spinner vessel. Then, cells could continuously grow in serum free medium with having specific growth rate of 0.106 (1/day) and specific scu-PA production rate of $1.58{\times}10_{-5}$(IU/cell/day) in batch cultivation.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.32 no.3
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• pp.272-278
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• 2006

Purpose: This study is designed to evaluate biocompatibility of three types of absorbable collagen GBR membrane in vitro. Material and Method: The human PDL fibroblasts culture was obtained through typical way and the cells used in the experiment was forth passage. The membranes examined were Experimental group A, B, C. All the 3-experimental groups were made of bovine pericardium and the membranes were excised into 5$\times$5mm respectively. The samples of the membranes were fixed on the 24-well plate with the double-sided adhesive tape. Then, 2ml of cell suspension which included $2{\times}10^4$cells was inoculated into the 24-well plate, and the cells were cultured for 1 week. Cellular viability and the alkaline phosphatase activity were measured with ELISA. The membranes in the culture were processed to examine with SEM. Results: The survival rate was highest in control and Experimental group A is the next, group B and group C in order of the value. The values are analyzed for statistical difference using Wilcoxon test. All the values of experimental groups are significantly lower than those of control, and the vaules among the experimental groups significantly differ from each other. Alkaline phosphatase level was identical order with the viable cell rate. SEM examination revealed that the PDL fibroblasts adherent on culture dish (control) and group A were spindle-shaped, but on group B and C, the cells were round-shaped without processes.

• Korean Journal of Materials Research
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• v.20 no.7
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• pp.392-400
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• 2010

The electrospinning process was established as a promising method to fabricate nano and micro-textured scaffolds for tissue engineering applications. A BCP-loaded PCL micro-textured scaffold thus can be a viable option. The biocompatibility as well as the mechanical properties of such scaffold materials should be optimized for this purpose. In this study, a composite scaffold of poly ($\varepsilon$-caprolactone) (PCL)-biphase calcium phosphate (BCP) was successfully fabricated by electrospinning. EDS and XRD data show successful loading of BCP nano particles in the PCL fibers. Morphological characterization of fibers shows that with a higher loaded BCP content the fiber surface was rougher and the diameter was approximately 1 to 7 ${\mu}m$. Tensile modulus and ultimate tensile stress reached their highest values in the PCL- 10 wt% BCP composite. When content of nano ceramic particles was low, they were dispersed in the fibers as reinforcements for the polymer matrix. However, at a high content of ceramic particles, the particles tend to agglomerate and lead to decreasing tensile modulus and ultimate stress of the PCL-BCP composite mats. Therefore, the use of nano BCP content for distribution in fiber polymer using BCP for reinforcement is limited. Tensile strain decreased with increasing content of BCP loading. From in vitro study using MG-63 osteoblast cells and L-929 fibroblast like cells, it was confirmed that electrospun PCL-BCP composite mats were biocompatible and that spreading behavior was good. As BCP content increased, the area of cell spreading on the surface of the mats also increased. Cells showed the best adherence on the surface of composite mats at 50 wt% BCP for both L-929 fibroblast-like cells and MG-63 osteoblast cell. PCL- BCP composites are a promising material for application in bone scaffolds.

• KSBB Journal
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• v.13 no.1
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• pp.83-89
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• 1998

Using a cellulose macroporous microcarrier, HeLa cells were cultivated in 100mL spinner flask(Bellco Co., USA) and confluent cell laden microcarriers were subcultured by bead-to-bead cell transfer method. In macroporous mcirocarrier-HeLa system viable suspended cells played an important role in bead-to-bead cell transfer and that could be increased by use of RPMI-1640, a calcium-ion-reduced-media and high speed agitation. Successful bead-to-bead cell transfers were performed continuously three time in spinner flask. We applied this technique to produce recombinant Vaccinia virus which express $\beta$-galactosidase. Recombinant protein yield of bead-to-bead transferred culture was comparable to conventional microcarrier cultures that were inoculated by cells detached from T-flask. Although trypsinization is a useful method for subculturing microcarriers in some cases, that process adds quality control problem and handling steps to large scale cell production. There fore, bead-to-bead cell transfer technique offers another convenient and efficient scale-up method for continuous microcarrier cultures.