• Food Science and Preservation
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• v.19 no.4
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• pp.470-476
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• 2012

Enzymatic action and microbial growth degrade the quality of fresh-cut lettuce. Browning, a bad smell, and softening during storage are the major forms of quality deterioration. Health-oriented consumers tend to avoid foods treated with chemicals to maintain their freshness. This study was conducted to evaluate the change in the quality of fresh-cut lettuce with combined low-temperature blanching (LB) and ultrasonication (US). The optimum condition was selected using the response surface methodology (RSM), through a regression analysis with the following independent variables; the ultrasonication time (X1), blanching temperature (X2), blanching time (X3), and dependent variable; ${\Delta}E$ value (y). It was found that the condition with the lowest ${\Delta}E$ value occurred with combined 90s US and $45^{\circ}C$ 90s LB (US+LB). The combined treatment group (US+LB) was stored at $10^{\circ}C$ for 9 days with the control group and each single-treatment group, with low-temperature blanching and ultrasonication. Overall, the US+LB group had a significantly high $L^*$ value, which indicates significantly low $a^*$, $b^*$, ${\Delta}E$, browning index, PPO, and POD activity values, and a low total bacteria count (p < 0.05). The US+LB group also had the highest sensory score (except for aroma and texture; p > 0.05).

• Journal of Ginseng Research
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• v.25 no.4
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• pp.150-155
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• 2001

This study examined effects of the active ingredients from ginseng on paraquat(PQ) toxitity. Mice were given PQ(25mg/kg, ip) and then they were given total saponins (TS; 5mg/kg, orally), protopanaxadiol (PD; 5mg/kg, orally) and protopanaxatriol(PT; 5mg/kg, orally) per day for periods of 1,3 & 7 days. We measured the activities of superoxide dismutase (SOD), electrophoretic isozyme band, catalase (CAT) were compared in the liver of mouse that dose with PQ and/or TS, PD and PT. The activities of SOD, CAT were generally higher in PQ+PD group than others groups. Especially the activity of SOD was the highest in PQ+PD group than others groups. SOD isozyme separated into three bands by electrophoresis. One band was located to near the anode side and two bands were cathode side. As the results of treated with KCN, we were confiremed that the Cu, Zn-SOD was located to near the anode side but the Mn-SOD were cathode side. Our results suggested that an antioxidant effect of ginseng saponins elevated a protection ability to an oxidative damage by direct action of SOD, CAT and reinforced the synthetic ability of endogenous antioxidant material in living organism. Particularly, PD was a effective antioxidant compared with others.

• The korean journal of orthodontics
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• v.24 no.3 s.46
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• pp.659-672
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• 1994

Dental caries is one of the most prevalent dental diseases in Korea and its prevention is very important in orthodontic therapy. For the cleansing action of saliva itself and/or tooth-brushing is lowered in patient with fixed orthodontic appliance, oral hygiene of the patient becomes worse, which provides more favorable environment for micro-organisms. Chlorhexidine, one of the series of bisguanide, has been reported to be strong antimicrobial agent and very effective on Streptococcus mutans. The purpose of this study is to evaluate the possibility of chlorhexidine as a anticariogenic agent in fixed orthodontic therapy. We used the varnish containing chlorhexidine as a main ingredient for the chemical control of salivary S.mutans in patients with fixed appliance therapy We applied the varnish containing chlorhexidine on the labial and interproximal surface of the teeth before bonding and banding teeth of our patients(N=20) and compared to control group patients(N=20). Before the application of chlorhexidine varnish and four times periodically after the completion of fixed appliance set-up, we sampled saliva of both group patients and incuvate S.mutans for 24 hours. In the culture study of sampled saliva, counting the number of S.mutans colonies, we founded as follows : 1. In patients with fixed appliance therapy, the risk of dental caries increase when it compared to that of preorthodontic treatment ; The number of salivary S.mutans increase in Patient's oral cavity. 2. The experimental agent that contain chlorhexidine is effective to reduce the number of salivary S.mutans. 3. For the effect of this agent is not ever-lasting, periodical application is needed, and additional study for economical interval and number of application is needed.

• Asian Pacific Journal of Cancer Prevention
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• v.15 no.19
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• pp.8377-8382
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• 2014

Background: Oral squamous cell carcinoma (OSCC) is the sixth most common malignancy worldwide. Cancer development and progression require inactivation of tumor suppressor genes and activation of proto-oncogenes. The well recognized mechanism of action demonstrated for chemotherapeutic agents is induction of apoptosis via reactivation of p53. In this context, we evaluate the efficacy of IV and oral routes of our novel PH and temperature sensitive doxorubicin-methotrexate-loaded nanoparticles (DOX-MTX NP) in affecting p53 profile in an OSCC rat model. Methods: In this study, 120 male rats were divided into 8 groups of 15 animals each. The new formulated DOX-MTX NP and free doxorubicin were IV and orally given to rats with 4-nitroquinoline-1-oxide induced OSCC. Results: Results showed that both DOX and DOX-MTX-NP caused significant increase in mRNA levels of P53 compared to the untreated group (p<0.000). With both DOX and DOX-MTX NP, the IV mode was more effective than the oral (gavage) route (p<0.000). Surprisingly, in oral mode, p53 mRNA was not affected in DOX treated groups (p>0.05), Nonetheless, both IV and oral administration of MTX-DOX NP showed superior activity (~3 fold) over free DOX in reactivation of p53 in OSCC (p<0.000). The effectiveness of oral route in group treated with nanodrug accounts for the enhanced bioavailability of nanoparticulated DOX-MTX compared to free DOX. Moreover, in treated groups, tumor stage was markedly related to the amount of p53 mRNA (p<0.05). Conclusion: Both oral and IV application of our novel nanodrug possesses superior activity over free DOX-in up-regulation of p53 in a OSCC model and this increase in p53 level associated with less aggressive tumors in our study. Although, impressive results obtained with IV form of nanodrug (-21 fold increase in p53 mRNA level) but both forms of nanodrug are effective in OSCC, with less toxicity normal cells.

• Korean Journal of Community Nutrition
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• v.20 no.3
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• pp.165-177
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• 2015

Objectives: Based on individual and environmental characteristics of low-income children, we developed a nutrition education program for school-aged children from low-income families according to effective use in social welfare centers. Methods: We conducted in-depth group interviews to assess program needs in 28 participants, 10 low-income school-aged children and 9 of their care givers, 9 social workers and 9 care-givers. Theoretical backgrounds of our program were heath belief model and social cognitive theory considering motivation, action and environment characteristics. Results: Based on the findings of this qualitative study, we developed major program themes and contents. Five selected key themes were 'balanced diet', 'processed food', 'food hygiene and safety', 'Korean healthy traditional diet', and 'family cooking' to induce changes in dietary behaviors. Main findings of in-depth group interviews included 'child's active participation', 'simple and easy to understand messages', and 'environmental constraints' such as a lack of child care at home, limited budget of social welfare centers, and less qualified educators for nutrition and health. Each lesson was constructed as a 1-hour program particularly emphasizing activity-based programs, including cooking and teamwork exercises. Program contents in each session consisted of activities that could induce outcome and value expectations, self-efficacy, perceived benefits, and barriers and cues to actions regarding diet behavior. Conclusions: We developed a nutrition education programthat is rarely available for low-income children in Korea, considering theoretical bases. Further studies are needed to validate our program.

• Preventive Nutrition and Food Science
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• v.3 no.3
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• pp.282-286
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• 1998

To determine the immune effect of kimchi extracts in mice, 0.5mg/day of the extracts from kimchis, which were prepared with conventionally (general kimchi)and organically(organic kimchi) cultivated ingredients, were treated orally to male BALB/c mice. Following 1, 3 and 5 weeks of treatment , the Interleukin-2(IL-2) production in the presence (con-A-stimulated )or the absence(spontaneous)of con A 95 $\mu\textrm{g}$/ml) and the natural killer cell (NK) activity of the splenocytes were measured. The IL-2 production in most of treatments with methanol extract from general kimchi were significantly higher than those of control(p<0.05).And at the 3 weeks of treatment, the spontaneous or con A-stimulated IL-2 productions from splenocytes of mice treated with it increased more than those of control group, by 2.8 and 2.2 times, respectively. However, the longer the treatment with methanol extracts from organic kimchi showed the higher the enhancing effect on the IL-2 production. The spontaneous or con A-stimulatdIL-2 productions form splenocytes of mice treated with dicholoromethyane fraction from general kimchi also increased at 5 weeks of treatment compared to those of control group, by 2.7 and 2.5 times, respectively. The natural killer cell activity of splenocytes from mice treated with methano lextracts from general kimchi for 1 ~5 weeks significantly higher than that of control goup (p<0.01). The effect of methano extracts from general kimchi was the highest at 3 weeks of treatment, as same as in the IL-2 production. The enhancing effect of methano extracts from organic kimchi on the NK cell activity was the highest at 5 weeks of treatment . The NK cell activity of splenocytes from mice treated with dichloromethane fraction from general kimchi for 5 weeks was significantly higher than those in control and 3 weeks of treatment. These results showed that the effects of kimchi extracts on the IL-2 production and the NK cell activity in mice were profound in long term of treatment (3 and 5 weeks than 1 week) . We suggest that kimchi extracts might have an immune effect in part due to its enhancing action on the IL-2 production and the NK cell activity.

• Journal of the korean academy of Pediatric Dentistry
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• v.24 no.1
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• pp.204-219
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• 1997

The use of fluoride is one of the most effective methods for caries prevention. Fluoridation of public water supply has been recognized, for many years, as an effective way to reduce dental caries. The fluoride supplement has been recommended when the natural fluoride was unavailable or below the optimal range. However the mechanism of caries prevention by fluoride has not yet been clarified and it is well known that an overdose of fluoride results inacute and chronic toxicity, especially dental fluorosis. Fluoride mouthrinsing solution is widely used in dentistry due to its effectiveness in carrying anticariogenic action. Understanding the effects of fluoride mouthrinsing solution on human gingival fibroblasts will provide the safety rationale for its use during the caries preventive therapy. The purpose of this study was to evaluate the cytotoxic effect of fluoride mouthrinsing solution on the human gingival fibroblast in vitro. The human gingival fibroblasts were cultured from healthy gingiva on the extracted deciduous teeth of children. Cells were inoculated into a 24-well plate with $1{\times}10^4cells/well$ of medium at $37^{\circ}C$, 100% humidity, 5% $CO_2$ incubator for 24 hours. And the cells were counted by using the hemocytometer at each designed study. Human gingival fibroblasts were cultured in growth medium after one minute application range of 0.02%-0.2% NaF solution and 0.1% $SnF_2$ solution. The cells used in this study were between fifth to eighth passage number. The cell morphology was examined by inverted microscope and cell proliferation was measured by incorporating $[^3H]$-thymidine into DNA. DNA synthesis by human gingival fibroblasts was assessed by $[^3H]$-thymidine uptake assays while the cell activity was measured by MTT assay. Each concentrated fluoride mouthrinsing solution was estimated for its biocompatability with fibroblasts by the tissue culture technique. The results of this study were as follows : 1. It was observed that at 0.05%, 0.2% NaF mouthrinsing solution the cytoplasmic processes became globular. When 0.1% $SnF_2$ mouthrinsing solution was applied, the cytoplasmic process and cell morphology were disappeared. 2. DNA synthetic activity was reduced regardless of the concentration of the fluoride mouthrinsing solution. However, the result is statistically insignificant except 0.1% $SnF_2$ mouthrinsing solution(p<0.05). 3. Our results indicate that 0.02%, 0.05% concentrations of NaF mouthrinsing solution caused minimal cytotoxicity. But 0.2% NaF and 0.1% $SnF_2$ concentration were a significant difference between the cell activity in the experimental group and control group (p<0.05). 4. After appling 0.05% & 0.02% NaF fluoride mouthrinsing solution, cell activity was restored to the control groups level according to incubating time. The results suggest that direct exposure to fluoride solution inhibits gingival fibroblast activity. Therefore, for the most effective use of fluoride use, lowering the concentration of fluoride mouthrinsing is advisable because it maintains biocompatability and free ion in the oral fluid.

• Development and Reproduction
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• v.15 no.4
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• pp.273-279
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• 2011

Epigenetic regulation is a phenomenon that changes the gene function without changing the underlying DNA sequences. Epigenetic status of chromosome is regulated by mechanisms such as histone modification, DNA modification, and RNAi silencing. In this review, we focused on histone methylation for epigenetic regulation in ES cells. Two antagonizing multiprotein complexes regulate methylation of histones to guide expression of genes in ES cells. The Polycomb repressive complex 2 (PRC2), including EED, EZH2, and SUZ12 as core factors, contributes to gene repression by increasing trimethylation of H3K27 (H3K27me3). In contrast, the Trithorax group (TrxG) complex including MLL is related to gene activation by making H3K4me3. PRC2 and TrxG accompany a variety of accessory proteins. Most prominent feature of epigenetic regulation in ES cells is a bivalent state in which H3K27me3 and H3K4me3 appear simultaneously. Concerted regulation of PRC2, TrxG complex, and H3K4- or H3K27-specific demethylases activate expression of pluripotency-related genes and suppress development-related genes in ES cells. Modified balance of the regulators also enables ES cells to efficiently differentiate to a variety of cells upon differentiating signals. More detailed insights on the epigenetic regulators and their action will lead us to better understanding and use of ES cells for future application.

• Toxicological Research
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• v.23 no.1
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• pp.55-63
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• 2007

Diethylnitrosamine (DEN) is a nitrosamine compound that can induce a variety of liver lesions including hepatic carcinoma, forming DNA-carcinogen adducts. In the present study, microarray analyses were performed with Affymetrix Murine Genome 430A Array in order to identify the gene-expression profiles for DEN and to provide valuable information for the evaluation of potential hepatotoxicity. C57BL/6NCrj mice were orally administered once with DEN at doses of 0, 3, 7 and 20 mg/kg. Liver from each animal was removed 2, 4, 8 and 24 hrs after the administration. The histopathological analysis and serum biochemical analysis showed no significant difference in DEN-treated groups compared to control group. Conversely, the principal component analysis (PCA) profiles demonstrated that a specific normal gene expression profile in control groups differed clearly from the expression profiles of DEN-treated groups. Within groups, a little variance was found between individuals. Student's t-test on the results obtained from triplicate hybridizations was performed to identify those genes with statistically significant changes in the expression. Statistical analysis revealed that 11 genes were significantly downregulated and 28 genes were upregulated in all three animals after 2 h treatment at 20 mg/kg. The upregulated group included genes encoding Gdf15, JunD1, and Mdm2, while the genes including Sox6, Shmt2, and SIc6a6 were largely down regulated. Hierarchical clustering of gene expression also allowed the identification of functionally related clusters that encode proteins related to metabolism, and MAPK signaling pathway. Taken together, this study suggests that match with a toxicant signature can assign a putative mechanism of action to the test compound if is established a database containing response patterns to various toxic compounds.

• Journal of Physiology & Pathology in Korean Medicine
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• v.21 no.5
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• pp.1127-1134
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• 2007

The study was designed to investigate the mechanism of Patholoobi Caulis freeze dried powder (PCF) on the regional cerebral blood flow (rCBF) and mean arterial blood pressure (MABP) in normal rats and cytokines production ($IL-1{\beta}$, $TNF-{\alpha}$, IL-10, $TGF-{\beta}$) in cerebral ischemic rats. The results in normal rats were as follows ; Increase of PCF-induced rCBF was significantly inhibited by pretreatment with methylene blue (10 ${\mu}g/kg$, I.p.), an inhibitor of guanylate cyclase, and was inhibited by indomethacin (1 mg/kg, i.p.), an inhibitor of cyclooxygenase. Increase of PCF-induced MABP was decreased by pretreatment with methylene blue, but was increased by indomethacin. These results suggested that the mechanism of action PCF was mediated by cyclic 3',5'-guanosine monophosphate. The results in cerebral ischemic rats were as follows ; In cytokine production in serum from femoral arterial blood 1 hr after middle cerebral arterial occlusion, PCF (10 mg/kg. i.p.) significantly decreased $IL-1{\beta}$ and $TNF-{\alpha}$ production, and increased IL-10 production compared with control group. In cytokine production in serum from femoral arterial blood 1 hr 1 hr after reperfusion, PCF (10 mg/kg, i.p.) significantly decreased $IL-1{\beta}$ production, and incresed IL-10 production compared with control group. These results suggested that PCF was significantly and stably increased regional cerebral blood flow by inhibiting $IL-1{\beta}$ production, and by accelerating IL-10 production.