• Korean Journal of Food Science and Technology
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• v.42 no.5
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• pp.586-592
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• 2010

This study investigated the effects of Stevia rebaudian bertoni leaf extract on lipid profiles in C57BL/6J mice, as compared to stevioside. Fourty mice were divided into four groups: NC (normal diet and DW), HC (high fat diet and DW), HLSV (high fat diet and stevia leaf extract, 1 mL/kg/day), and HSS (high fat diet and stevioside, 1 mL/kg/day). Serum triglyceride concentrations were significantly lower in the HLSV and HSS groups than in the HC group. Epididymal fat pad weights were significantly lower in the HLSV and HSS groups than in the HC group. We also evaluated the serum and liver carnitine levels (NEC, AIAC, ASAC, TCNE) of all the groups. These results were supported by the mRNA expression of enzymes related to lipid metabolism (ACC, PPAR${\alpha}$, ACS, CPT-I) assessed by RT-PCR. Overall, the results show the antiobesity effects of stevia leaf extract as compared to stevioside in high fat diet induced obese mice.

• Development and Reproduction
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• v.6 no.1
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• pp.55-66
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• 2002

Embryonic stem cells(ES cells) are derived from the inner cell mass(ICM) of blastocysts, which have the potentials to remain undifferentiated, to proliferate indefinitely in vitro, to differentiate into the derivates of three embryonic germ layers. ES cells are an attractive model system for studying the initial developmental decisions and their molecular mechanisms during embryogenesis. Additionally, ES cells of significant interest to those characterizing the various gene functions utilizing transgenic and gene targeting techniques. We investigated the effects of reproductive hormones, gonadotropins(GTH) and steroids on the induction of differentiation and expressions of their receptor genes using the newly established mouse ES cells. We collected the matured blastocysts of inbred mice C57BL/6J after superovulation and co-cultured with mitotically inactivated STO feeder cells. After 5 passages, we confirmed the expression alkaline phosphatase(Alk P) activity and SSEA-1, 3, 4 expressions. The protocol devised for inducing ES differentiation consisted of an aggregation steps, after 5 days as EBs in hormone treatments(FSH, LH, E$_2$, P$_4$, T) that allows complex signaling to occur between the cells and a dissociation step, induced differentiation through attachment culture during 7 days in hormone treatments. Hormone receptors were not increased in dose-dependent manner. All hormone receptors in ES cells treated reproductive hormones were expressed lower than those of undifferentiated ES cell except for LHR expression in E$_2$-treated ES cells group. After hormone induced differentiation, at least some of the cells are not terminally differentiated, as is evident from the expression of Oct-4, a marker of undifferentiated. To assess their differentiation by gene expression, we analyzed the expression of 7 tissue-specific markers from all three germ layers. Most of hormone-treated group increased in the expression of gata-4 and $\alpha$ -fetoprotein, suggesting reproductive hormone allowed or induced differentiation of endoderm.

• Journal of Animal Science and Technology
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• v.53 no.4
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• pp.377-385
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• 2011

This study was carried out to investigate quality characteristics of dry-cured hams in the domestic market. Two kinds of dry-cured hams were processed with pork leg (T1) and pork neck (T2). Five 24-month dry-cured legs (T1, 5.3-6.1 kg) and twenty 4-month dry-cured pork necks (T2, 1.5-1.9 kg) were used in this experiment. They were stored at $4^{\circ}C$ chilling room and quality characteristics were investigated. Moisture content, water activity, cholesterol content, CIE $L^*$, VBN, total plate counts and lactic acid bacteria of T1 were significantly higher (p<0.05) than those of T2, whereas fat content, ${NO_2}^-$, CIE $a^*$, TBARS and Warner-Bratzler shear force values of T2 were significantly higher (p<0.05) than those of T1. In fatty acid compositions, palmitoleic acid and stearic acid in T2 were significantly higher (p<0.05) than T1, however, oleic and linoleic acid in T2 was significantly lower (p<0.05) than T1. In free amino acids, the total content and individual content of asparagin, leucine and phenylalanine in T1 were higher than those of T2 (p<0.05). The aroma score of T2 was higher than that of T1 in sensory evaluation (p<0.05). In conclusion, two kinds of dry-cured hams were different in their final characteristics and could enhance the consumer's appeal of pork meat in Korean market.

• Korean Journal of Environmental Agriculture
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• v.30 no.2
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• pp.169-178
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• 2011

BACKGROUND: This study aimed to estimate the measurement uncertainty associated with determination of cadmium and lead from tomato paste by ICP/MS. The sources of measurement uncertainty (i.e. sample weight, final volume, standard weight, purity, molecular weight, working standard solution, calibration curve, recovery and repeatability) in associated with the analysis of cadmium and lead were evaluated. METHODS AND RESULTS: The guide to the expression of uncertainty was used for the GUM (Guide to the expression of Uncertainty in Measurement) and Draft EURACHEM/CITAC (EURACHEM: A network of organization for analytical chemistry in Europe/Co-Operation on International Traceability in Analytical Chemistry) Guide with mathematical calculation and statistical analysis. The uncertainty components were evaluated by either Type A or Type B methods and the combined standard uncertainty were calculated by statistical analysis using several factors. Expected uncertainty of cadmium and lead was $0.106{\pm}0.015$ mg/kg (k=2.09) and $0.302{\pm}0.029$ mg/kg (k=2.16), on basis of 95% confidence of Certified Reference Material (CRM) which was within certification range of $0.112{\pm}0.007$ mg/kg for cadmium (k=2.03) and $0.316{\pm}0.021$ mg/kg for lead (k=2.01), respectively. CONCLUSION(s): The most influential components in the uncertainty of heavy metals analysis were confirmed as recovery, standard calibration curve and standard solution were identified as the most influential components causing uncertainty of heavy metal analysis. Therefore, more careful consideration is required in these steps to reduce uncertainty of heavy metals analysis in tomato paste.

• Korean Journal of Environmental Biology
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• v.20 no.1
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• pp.73-77
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• 2002

The effect of salicylic acid (SA) on C $d^{2+}$ - induced physiological toxicity in Commelina communis was investigated. 3- weeks old Commelina communis was transferred to and grown in Hoagland solution in the presence or absence of 100 $\mu$M C $d^{2+}$ and SA for 3 weeks. In the treatment of C $d^{2+}$ + SA, the length of stem was increased to 0.7 cm for 3 weeks (C $d^{2+}$, 2.1cm; control, 7.2 cm). C $d^{2+}$ + SA reduced total chlorophyll content up to 86%, and changed chlorophyll a/b ratio below 1.6. C $d^{2+}$ + SA also reduced about 40-78% of water potential, but C $d^{2+}$ increased 16-39% from 1 week to 3 weeks. C $d^{2+}$ + SA also inhibited 27% of Fv/Fm, but in case of C $d^{2+}$, Fv/Fm was not changed. The treatment of C $d^{2+}$ + SA showed about 37-58% inhibition of photosynthetic activity when measured at various light intensity (500-1000 $\mu$mol $m^{-2}$ $s^{-1}$ ). In the case of C $d^{2+}$ treatment, photosynthetic activity was inhibited to 12-15%. Similar effect was found in terms of stomatal conductance. Therefore, it could be concluded that the treatment of C $d^{2+}$ + SA into plant decrease or block various physiological activities and lend to die by double effects of both chemicals.cts of both chemicals..

• Journal of Life Science
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• v.17 no.2 s.82
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• pp.198-203
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• 2007

DNA transfection is a powerful tool for studying gene functions. The $Ca^{2+}$-phosphate precipitation remains one of the most popular and cost-effective transfection techniques. Mature neurons are more resistant to transfection than young ones and most other cell types, and easy to die if microenvironment changes. Here, we report a transfection protocol for mature neurons. The critical modifications are inclusion of glial cells in culture and careful control of $Ca^{2+}$-phosphate precipitation under microscope. Cerebral glial cells were grown until ${\sim}70-80%$ confluence in DMEM/10% horse serum, which was thereafter replaced with serum-free Neurobasal/Ara-C, and 319 hippocampal neurons were plated onto the glial layer Formation of fine $DNA/Ca^{2+}$-phosphate precipitates was induced using Clontech $CalPhos^{TM}$ Mammalian Transfection Kit, and the size ($0.5-1\;{\mu}m$ in diameter) and density(about 10 particles/$100\;{\mu}m^2$) were carefully controlled by the time of incubation in the medium. This modified protocol can be reliably applied for transfection of mature neurons that are maintained longer than two weeks in vitro, resulting in 10-15 healthy transfected neurons per a well of 24-well plates. The efficacy of the protocol was verified by punctate expression of $pEGFP-CaMKII{\alpha}$, a synaptic protein, and diffuse expression of pDsRed2. Our protocol provides a reliable method for transfection of mature neurons in vitro.

• Journal of Life Science
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• v.25 no.5
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• pp.548-556
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• 2015

Three groups of black seabream (Acanthopagrus schlegeli) were fed with treatment diets containing certain concentrations of conjugated linoleic acid (CLA) and carotenoids. The control group feed contained 0% CLA and 0% carotenoids, the CP10 group feed contained 1% CLA and 0.1% carotenoids, and the CP25 group feed contained 2.5% CLA and 0.1% carotenoids. The CP10 and CP25 groups demonstrated the enhanced growth and increased feed conversion efficiency of black seabream. The specific growth rates (SGRs) were 0.74, 0.81, and 0.97, while the feed conversion ratios (FCRs) were 2.65, 2.46, and 2.04 for the control, CP10, and CP25 groups, respectively. The total contents of high unsaturated fatty acid (HUFA) for the control, CP10, and CP25 groups were 41.0%, 41.7%, and 43.5%, respectively. CLA was deposited to the extent of 2.8% and 5.6% in the muscle, and 4.0% and 8.3% in the viscera of the CP10 and CP25 groups, respectively. Meanwhile, treatment with the viscera lipid extract (VLE) from CP25 fish evidently lowered 3T3-L1 adipocytes viability. The lipid extract from the muscle and viscera of black seabream contained ample amounts of beneficial substances, such as CLA, carotenoids, EPA, and DHA. CLA, which enriched black seabream muscle, could be categorized as a functional food and serve as a well-being food. Meanwhile, the fish oil from its viscera could serve as a high function supplement.

• Journal of Life Science
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• v.27 no.2
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• pp.155-163
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• 2017

Mori Folium, the leaf of Morus alba, is a traditional medicinal herb that shows various pharmacological activities such as antiinflammatory, antidiabetic, antimelanogenesis, antioxidant, antibacterial, antiallergic, and immunomodulatory activities. However, the mechanisms of their inhibitory effects on adipocyte differentiation and adipogenesis remain poorly understood. In the present study, we investigated the inhibition of adipocyte differentiation and adipogenesis by ethanol extracts of Mori Folium (EEMF) in 3T3-L1 preadipocytes. Treatment with EEMF suppressed the terminal differentiation of 3T3-L1 preadipocytes in a dose-dependent manner, as confirmed by a decrease in the lipid droplet number and lipid content through Oil Red O staining. EEMF significantly reduced the accumulation of cellular triglyceride, which is associated with a significant inhibition of pro-adipogenic transcription factors, including sterol regulatory element-binding protein-1c (SREBP-1c), peroxisome proliferator-activated receptor-${\gamma}$ ($PPAR{\gamma}$), and CCAAT/enhancer-binding proteins ${\alpha}$ ($C/EBP{\alpha}$) and ${\beta}$ ($C/EBP{\beta}$). In addition, EEMF potentially downregulated the expression of adipocyte-specific genes, including adipocyte fatty acid binding protein (aP2) and leptin. Furthermore, EEMF treatment effectively increased the phosphorylation of the AMP-activated protein kinase (AMPK) and acetyl CoA carboxylase (ACC); however, treatment with a potent inhibitor of AMPK, compound C, significantly restored the EEMF-induced inhibition of pro-adipogenic transcription factors and adipocyte-specific genes. These results together indicate that EEMF has preeminent effects on the inhibition of adipogenesis through the AMPK signaling pathway, and further studies will be needed to identify the active compounds in Mori Folium.

• Journal of the Korean Society of Food Science and Nutrition
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• v.37 no.6
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• pp.684-690
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• 2008

To investigate the applicability of hot water extract (PLW) and ethanol extract (PLE) from Phellinus linteus as functional food and cosmeceutical materials, its total flavonoids content, total phenolics content, electron donating ability (EDA), nitrite-scavenging ability (NSA), SOD-like activity, inhibitory effect of tyrosinase and elastase were examined. Total flavonoids contents of PLW and PLE were 17.31 mg/g and 42.61 mg/g, respectively, and total phenolics contents were estimated as 149.92 mg/g for PLW and 432.42 mg/g for PLE. The EDA of PLW and PLE were $6.49{\sim}92.98%$ and $22.61{\sim}94.28%$. The EDA and total phenolics contents had a high correlation of 0.83. The NSA was pH dependent, and was highest at pH 1.2 and lowest at pH 6.0. The NSA of PLE was higher than that of PLW. The SOD-like activities of PLW and PLE were $14.36{\sim}35.21%$ and $17.27{\sim}81.84%$, respectively, and the activity was dependent on the sample concentration. The tyrosinase inhibitory activity was the highest in PLE ($10.51{\sim}80.93%$) while that of PLW was $4.77{\sim}43.69%$. Finally, the elastase inhibitory activity was $10.01{\sim}76.02%$ at PLE. Based on the above results, we deemed that the ethanol extract of Phellinus linteus was the most pertinent for use as functional food and cosmeceutical materials.

• Applied Biological Chemistry
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• v.19 no.4
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• pp.219-226
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• 1976

To meet the need of protein feed and fine more efficient ways of returning waste to resources, we have carried out the study of the production of yeast for foods and feeds from the corn starch cake. The present study includes the method for acid-hydrolysis, the selection of yeast capable of utilizing hydrolyzate of the corn starch cake, and culture condition of Candida tropicalis under the liquid culture and the semisolid culture. Obtained results were as follows. 1. Hydrochloric acid was more excellent on the hydrolysis of the corn starch cake than sulfuric acid, and the yield of sugar was maximum, 57.2%, when the corn starch cake was hydrolyzed with 1.0% of hydrochloric acid at 2.0kg/cm for 30 minutes. 2. As the acid solution content was increased, more sugar was liberatedfrom the mixture, until the acid solution-substrate ratio reached 10:1. Beyond this point, no further increase was observed. To prepare the cultural medium of semisolid fermentation, a acid solution to substrate ratio of 3:1 appeared to be optimum. 3. Out of 6 yeast strains, Candida tropicalis had excellent growth on the hydrolyzate of the corn starch cake, and optimum temperature and initial pH were $30^{\circ}C$ and 6.0 respectively. 4. Optimum liquid medium of Candida tropicalis is ures 0.3%, potassium phosphate monobasic 0.15g and magnesium sulfate 0.04g in 100ml of the hydrolyzate of the corn starch cake, while optimum semisolid medium is ammonium chloride 0.4g, potassium phosphate monobasic 0.1%, magnesium sulfate 0.04%. 5. Candida tropicalis could assimilate the sugar in the hydrolyzate up to more than 88.75%, and a yield of dry yeast reached 19.13% to the corn starch cake under the liquid culture. 6. Compared to the that of the untreated corn starch cake, the cellulose content of the semisolid fermented cake decreased by 3.76% to 14.7%, whereas dry yeast contents increased by 13.89%.