• Journal of Plant Biotechnology
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• v.31 no.1
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• pp.43-48
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• 2004

As an initial step for future genetic manipulations to improve forage characteristics of Italian ryegrass (Lolium multiflorum Lam.), an efficient tissue culture system was established and the factors affecting plant regeneration were evaluated. MS medium containing 5mg/L 2,4-D was optimal for embryogenic callus induction from mature seed and had a strong effect on successive plant regeneration. The plant regeneration frequency was observed at above 70％ when embryogenic calli induced were transferred to N6 medium supplemented with 1mg/L 2,4-D and 5mg/L BA. Among several basic media tested, MS and N6 medium were optimal for callus induction and plant regeneration, respectively. Genotype was an important factor in plant regenerability. 'Jeanne' showed the highest regeneration frequency of 73％. A short tissue culture period and high-frequency regeneration system established in this study will be useful for molecular breeding of Italian ryegrass through genetic transformation.

• 재활복지
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• v.21 no.3
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• pp.23-47
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• 2017

This study examines the mediating effects of self-efficacy between self-differentiation and depression by analyzing 105 parents who have at least one child with a disability. Regression analysis confirmed all hypothesis between self-differentiation, self-efficacy, and depression. There exists partially or complete mediation. That is the indirect effect on depression, self-efficacy explains the relationships between self-differentiation and depression to be as minimum as 24 percent to as maximum as 100 percent. This demonstrates that the self-efficacy significantly affects the relationship between self-differentiation and depression. Findings of this study recommend that self-efficacy should be enhanced through improving the level of self-differentiation. The results also imply that rehabilitation counselors need to understand the way of improving self-efficacy as well as the fact that the influencing factors of self-differentiation on self-efficacy is important. The findings of this study are informative for researchers, educators, and clinicians for mental health and psychological rehabilitation who assist the parents of children with disabilities.

• Journal of Yeungnam Medical Science
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• v.5 no.2
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• pp.111-119
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• 1988

To elucidate the effects of dimethyl sulfoxide on myocardial and endothelial cells in culture, the cells were exposed to 10% dimethyl sulfoxide in culture medium for 1 hour at 48 hours after cell isolation. The general morphology and the cytochemical reaction of marker enzymes for mitochondria and Golgi complexes were investigated. The results were summarized as follows. : 1. DMSO induced elongation and narrowing of the cells and increase of mitochondrial reaction in myocardial cells. 2. DMSO induced destruction and disruption of myofibrils in myocardial cells resulting in increase of contractile activities. 3. In the endothelial cells, DMSO suppressed proliferative activities but thiamine pyrophosphatase reactions were enhanced indicating increase of Goigi complex activity. 4. DMSO seemed to hamper with the adhesiveness and motility of the endothelial cells causing the decrease of the number of cells in vitro.

• Korean Journal of Plant Resources
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• v.11 no.1
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• pp.1-8
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• 1998

This study was conducted to establish mass propagation system from the axillary bud culture of chrysanthemum zawadskii H. which was used as material of medicinal plants. Shoot egeneration was better on MS medium with NAA and BA. The optimum concentraions of growth regulator for shoot regeneration differed depending on accessionsof C. Zawadskii. Shoot regeneration in Keungucheolcho was better on MS Medium with NAA 0.01mg/1 and BA 0.1mg/1 while Hyangrobonggucheocho was better with NAA 0.1mg/1and BA 0.3mg/1. Addition of NAA into medium was effective for induction of root from shoots regenerated. Shoot multiplcation was more effective when 10mg/1 spermine was added into medium than when other polyamines were treated ino medium . Randomly and specifically amplified polymorphic DAC banding patterns based on polymerase chain reaction (PCR) analysis were used to assess the genetic variation of plants regenerated from in vitro culture.

• Journal of Life Science
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• v.19 no.4
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• pp.423-428
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• 2009

Selenium was investigated using human origin preadipocytes to see whether it possesses preventive or therapeutic effects for obesity. Unveiling the potential of selenium in the reduction of adipogenesis can help predict the therapeutic capabilities of selenium in obesity. In the present study, the molecular mechanism of the inhibition of adipogenesis by selenium was explored to unravel the involvement of the AMP-activated protein kinase. There is emerging evidence that AMPK, a sensor of cellular energy status, is a possible molecular target of controlling adipocyte differentiation on the basis of discovery that AMPK is responsible for the major metabolic responses to exercise, and integration of nutritional and hormonal signals to modulate feeding behavior or energy expenditure in the hypothalamus. Treatment of selenium resulted in inhibition of the adipocyte differentiation process and induction of mature apoptosis in 3T3-L1 adipocytes. We hypothesized that selenium may exert anti-adipogenic potential though modulating AMPK. We have found that selenium significantly activated AMPK and phosphorylated its substrate acetyl-CoA carboxylase ($ACC-serine^{79}$) during the inhibitory process of adipocytes. Also, the inhibition process of adipocyte differentiation by selenium was comparable to either reveratrol or a synthetic AMPK activator, AICAR (5-aminoimidazole-4-carboxamide-1-${\beta}$-D-ribofuranoside). To evaluate the involvement of AMPK in anti-lipogensis, we applied AICAR and Compound C, an AMPK inhibitor, to 3T3-L1-adipocytes and found that AMPK is required for the adipocyte differentiation blocking process. These results suggest that selenium has a potential to control adipogenesis and that this effect is mediated by AMPK, an essential kinase for both inhibition of adipocyte differentiation and apoptosis of mature adipocytes.

• Journal of Animal Science and Technology
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• v.47 no.6
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• pp.1067-1074
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• 2005

In order to optimize tissue culture conditions of Kentucky bluegrass(Poa pratensis L.), effects of culture medium supplements, media and cultivars on embryogenic callus induction and regeneration of plants were investigated. MS medium containing 3mg/L 2,4-D and 0.1mg/L BA was optimal for embryogenic callus induction from mature seeds. The highest plant regeneration frequency(57.7%) was observed when the embryogenic calli were cultured on N6 medium supplemented with 1mg/L 2,4-D and 3mg/L BA. Among several basic media, MS and N6 medium were optimal for callus induction and plant regeneration, respectively. Genotype was an important factor in plant regenerability. ‘Newport’ showed to have higher regeneration frequency of 53.4%. Regenerated plants were grown normally when shoots transplanted to the soil. A short tissue culture period and high-frequency regeneration system would be beneficial for molecular breeding of Kentucky bluegrass through genetic transformation.

• Journal of Plant Biotechnology
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• v.35 no.2
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• pp.133-140
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• 2008

The modification of DNA and histone plays an important role for gene expression in plant development. The objective of this research is to observe the effects of methylation on the gene expression during dedifferentiation from rice mature seeds to callus and differentiation from callus to shoots. The embryogenic callus with ability to shoot regeneration was not induced on the N6A medium supplemented with 5-azacytidine and abnormal callus with brown color was formed. When the normal rice callus was placed on the regeneration MSRA medium supplemented with 5-azacytidine, the shoot regeneration was inhibited. The results showed that 5-azacytidine, DNA demethylating agent, had negative effects on normal embryogenic callus formation and shoot regeneration. This suggested that DNA methylation of some genes was required for normal cell dedifferentiation and differentiation in tissue culture. The microarray and $GeneFishig^{TM}$ DEG screening were used to observe the gene transcript profile in callus induction and regeneration on N6A (N6 medium + 5-azaC) and MSRA (MS regeneration medium + 5-azaC). Subsets of genes were up-regulated or down-regulated in response to 5-azaC treatments. The genes related with epigenetic regulation, electron transport, nucleic acid metabolism and response to stress were up and down regulated. The different expression of some genes (germin like protein etc.) during callus induction and shoot regeneration was confirmed using RT-PCR and northern blot analysis.

• Journal of Korean Ophthalmic Optics Society
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• v.18 no.4
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• pp.541-548
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• 2013

Purpose: Marrow stromal cells (MSCs) have been known for their potential to trans-differentiate into neural and glial cells in vitro and in vivo. To investigate the influence of the developing host environment on the survival and morphological and molecular differentiation, murine MSCs transplanted into the eye of Brazilian opossum (Monodelphis domestica). Methods: Enhanced green fluorescent protein (GFP) - expressing MSCs were transplanted into developing Brazilian opossums. Animals were allowed to survive for up to 4 weeks after transplantation, at which time the eyes were prepared for immunohistochemical analysis. Results: Some transplanted MSCs survived and showed morphological differentiation into neural cells with some processes within the host vitreous chamber. Some transplanted cells expressed class III ${\beta}$-tubulin (TuJ1, a marker for neuronal cells) or glial fibrillary acid protein (GFAP, a marker for glial cells) or Nestin (a marker for neural stem cells). In addition, some transplanted cells were located in ganglion cell layer but did not show morphological and molecular differentiation. Conclusions: Our result show that the most effective stage of development for transplantation into the retina was postnatal day 16, which retinas developmentally corresponded to postnatal day 4-5 days mouse retina based on cell differentiation and lamination patterns. The present findings suggest that the age of the host appears to play a key role in determining cell fate in vivo.

• Journal of Life Science
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• v.26 no.12
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• pp.1355-1359
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• 2016

Human bone marrow mesenchymal stem cells (hBM-MSCs) can differentiate into various cell types including osteoblasts, adipocytes, chondrocytes, and myocytes. Previous studies, including our own, have shown that MSCs can also differentiate into neuron-like cells. However, their rate of neuronal differentiation is not sufficient for application to stem cell therapy, which requires well-defined cell types. For this purpose, we first examined the expression of neuronal lineage markers (GFAP, MAP-2, KCNH1, Nestin, NF-M, and Tuj-1) by real-time PCR, western blot, and immunocytochemical staining. The expressions of the astrocyte marker GFAP and neuronal markers NF-M and Tuj-1 increased in neuronal differentiated MSCs (dMSCs). To improve the neuronal differentiation efficiency, PDE4, an important signaling intermediator in the progression of neuronal differentiation, was modulated using well-known inhibitors such as rolipram or resveratrol and then differentiated into neuronal cells (Roli- or RSV-dMSCs). The expressions of NF-M, Tuj-1 were increased while that of GFAP decreased in Roli- and RSV-dMSCs, which were examined by real-time PCR, western blot, and immunocytochemical staining. From these experiments, we have found that the neuronal differentiation efficiency can be ameliorated by the modulation of PDE4 activity.

• Korean Journal of Clinical Laboratory Science
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• v.47 no.3
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• pp.117-124
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• 2015

Mesenchymal stem cells (MSCs) are an attractive tool in tissue engineering as they have the required potential to treat injured articular cartilage. UV-exposed DTOPV (S-triazine bridged p-phenylene vinylene) is a biocompatible and fluorescent polymer with a hydrophilic surface. Previous studies have demonstrated that the surface wettability and hydrophilicity play critical roles in regulating cell adhesion and proliferation. The objective of this study was to improve the potential of in vitro MSC differentiation into Chondrocytes using DTOPV. MSCs were cultured on two different substrates: (1) tissue culture polystyrene (TCPS) as a reference and (2) UV-exposed and patterned DTOPV films. Chondrogenesis of MSCs was induced for two weeks on TCPS and DTOPV in the presence of an induction medium containing transforming growth factor (TGF)-${\beta}3$. Interestingly, the MSCs on TCPS adhered and spread, while those on DTOPV tended to form aggregates within several days. The cells cultured on DTOPV for two weeks had a round morphology, with stronger Safranine O staining of the extracellular matrix than that of the cells cultured on TCPS. Also, Type II collagen gene was significantly expressed in cells induced on DTOPV. These results indicate that chondrogenic differentiation of MSCs proceeds more rapidly on DTOPV than on TCPS. Therefore, in cartilage tissue engineering, DTOPV could be used to induce effective chondrogenic differentiation of MSCs.