• Korean Journal of Food Science and Technology
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• v.52 no.1
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• pp.103-108
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• 2020

Shiga toxin-producing Escherichia coli (STEC) is an important pathogenic bacteria and can cause severe foodborne disease. For STEC detection, conventional culture methods have disadvantages in the fact that conventional culture takes a long time to detect and PCR can also detect dead bacteria. To overcome these problems, we suggest a bacteriophage amplification assay, which utilizes the ability of bacteriophages to infect living cells and their high specificity. We used a combination of six bacteriophages infecting E. coli to make the bacteriophage cocktail and added ferrous ammonium sulfate as a virucidal agent to remove free-bacteriophages. When cherry tomato and paprika were artificially inoculated with the cocktail at a final concentration of around 3 log CFU/mL and were enriched for at least 5 h in mTSB broth with Novobiocin, approximately 2-3 log PFU/mL were detected through the bacteriophage amplification assay. Therefore, bacteriophage amplification assay might be convenient and a useful method to detect STEC in a short period of time.

• Journal of the Korean Society of Food Science and Nutrition
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• v.43 no.4
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• pp.624-629
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• 2014

Obesity is the leading metabolic disease in industrialized countries and is closely associated with coronary heart disease, hypertension, diabetes, and cancer. The objective of this study was to evaluate the anti-adipogenic effects of two roasted coffee beans, Vietnam robusta (VR) and Ethiopia Mocha Sidamo G2 (ES), as well as fermented coffee beans with Monascus ruber (MR) mycelium on differentiation of 3T3-L1 preadipocytes. Treatments with 1,000 ${\mu}g/mL$ of hot water extract from coffee beans significantly reduced intracellular lipid accumulation. In addition, VR more effectively inhibited transcription factors such as $PPAR{\gamma}$, $C/EBP{\alpha}$, FAS, and aP2 compared to ES. Further, ES fermented with MR showed more effective anti-adipogenic activity than non-fermented ES. These results suggest that VR and ES inhibit adipocyte differentiation which may contribute to their anti-adipogenic properties.

• Fisheries and Aquatic Sciences
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• v.5 no.2
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• pp.108-113
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• 2002

Apical and subapical fragments of Gracilaria verrucosa (Hudson) Papenfuss (Rhodophyta) were cultured on a temperature-light gradient table with four temperature $(15,\;20,\;25\;and\;30^{\circ}C)$ and five light intensity $(20,\;40,\;60,\;80\; and\;100{\mu}mol\;photons\;m^{-2}s^{-l})$ regimes to examine growth responses. Their growth was measured weekly. Plant weight and lateral branch formation were affected by temperature and light intensity. As compared with other reports, relative growth rate (RGR) in both fragments was more or less high with 6.27 to $11.95\%$ $day^{-1}$. It was lowest at $15^{\circ}C$ with $20\mu mol$ photons $m^{-2}s^{-l}$, whereas, the highest value was recorded at $25^{\circ}C$ with $100\mu mol$ photons $m^{-2}s^{-l}$ During the experimental period, the growth pattern in G. verrucosa was significantly different between apical and subapical fragments, even though RGR based on weight was similar. Growth in apical fragments depended on elongation by apical growth. By contrast, subapical fragments mainly increased their weights by proliferation of lateral branch. This suggests that intercalary activity (e.g. lateral branch formation) is also an important means for growth of the thallus in Korean G. verrucosa. In conclusion, the relatively high growth potential with the intercalary activity in G. verrucosa will be helpful for mariculture in Korea.

• Fisheries and Aquatic Sciences
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• v.13 no.2
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• pp.96-101
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• 2010

Norovirus, which causes gastroenteritis in humans, is an important food-borne pathogen worldwide. In an effort to discover an antiviral substance against norovirus, extracts from several seaweeds were evaluated for antiviral activity against feline calicivirus (FCV), which was used as a surrogate. The methanolic extract of Undaria pinnatifida exhibited the most significant antiviral activity and virucidal efficacy against FCV. The concentrations of the extract that reduced viral replication by 50% ($EC_{50}$) and resulted in the death of 50% of the host cells ($CC_{50}$) were 0.05 mg/mL and 1.02 mg/mL, respectively. The selectivity index, calculated from the ratio of the $CC_{50}$ and $EC_{50}$ was 20.4. No FCV infection of host cells occurred following a 1-h incubation in the presence of 12.50 mg/mL U. pinnatifida extract, indicating that the virus was completely inactivated by the extract treatment. The results obtained in this study will contribute to the development of a natural antiviral substance that will prevent food-borne disease caused by norovirus.

• The Korea Journal of Herbology
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• v.31 no.5
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• pp.47-53
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• 2016

Objectives : Mori Follium (Morus alba L. leaf) has been cultivated in many Asian countries. Especially, mulberry leaf has been used as an anti-diabetic remedy in oriental medicine. However, anti-obesity effect of mulberry has not been unknown. In this study, our objectives of study is to investigate the anti-adipogenic effect of mulberry water extract (MLE) and to reveal potential molecular anti-obesity mechanism in 3T3-L1 adipocytes differentiation model.Methods : The cytotoxicity of MLE in 3T3-L1 was examined by MTT assay. Anti-adipogenic effect of MLE was evaluated by Oil Red O (ORO) staining. To elucidate the molecular mechanism, inhibitor assay was employed. The mRNA expression levels of adipogenic transcriptional factors such as PPARγ and fatty acid synthase (FAS) were analyzed by reverse transcription-polymer chain reaction (RT-PCR) analysis.Results : The MLE treatment for 24 h did not affect to the 3T3-L1 cells at concentrations of 1, 10, 100, 200, 400, 800 and 1,000 ㎍/㎖. Thus, non-toxic concentration rages of MLE were used during adipogenesis period (day -2 to 7). Intracellular lipid accumulation in MLE-treated 3T3-L1 adipocytes (day 6) were quantitatively evaluated by ORO staining. The MLE treatment significantly and dose-dependently suppressed 3T3-L1 adipogenesis by 60.42%, 38.24%, and 5.97% at 10, 100, and 200 ㎍/㎖, respectively. In addition, our inhibitor assay and RT-PCR analysis revealed that the MLE-inhibited 3T3-L1 adipogenesis through inhibition of PPARγ mediated by Wnt/β-catenin signaling pathway.Conclusions : In conclusion, these findings indicate that the MLE could be used in prevent and/or treatment of obesity-related diseases.

• Fisheries and Aquatic Sciences
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• v.12 no.4
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• pp.293-298
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• 2009

Several studies have reported that nonylphenol (NP) and 2,2', 4,6,6'-pentachlorobiphenyl (PCB104) exhibit estrogenic activity. To investigate the estrogenic potency of NP and PCB104 during oocyte maturation, fully vitellogenic oocytes (0.76 mm diameter in average) of yellow fin goby, Acanthogobius flavimanus, were exposed in vitro to these chemicals at different concentrations (0.1, 1, 10, 100, and 1,000 ng/mL) with the exogenous precursor $17\alpha$-hydroxyprogesterone ($17{\alpha}OHP$) 50 ng/mL in the presence or absence of human chorionic gonadotropin (HCG). The production of testosterone (T), estradiol-$17\beta$ (E2), and $17\alpha,20\beta$-dihydroxy-4-pregnen-3-one ($17\alpha20{\beta}OHP$) in response to NP or PCB104 were measured by radioimmunoassay. Steroid levels were also expressed as E2/T and E2/$17\alpha20{\beta}OHP$ ratios. In the absence of HCG, no significant differences in either NP or PCB104 treatment groups were observed. In the presence of HCG, NP treatment did not show significant differences in the production of T, E2, and $17\alpha20{\beta}OHP$ at any concentrations tested, but E2/T ratios were decreased at concentrations of 0.1, 1, 10, and 1,000 ng/mL compared with the control group. PCB104 decreased E2 production at concentrations of 0.1, 10, and 1000 ng/mL, but did not show significant differences in the production of T and $17\alpha20{\beta}OHP$ at any concentration tested. While E2/T ratios were decreased at PCB104 concentrations of 0.1, 1, 10, and 1,000 ng/mL, E2/$17\alpha20{\beta}OHP$ ratios were also decreased at 0.1, 10, and 1,000 ng/mL compared with the control. Results indicate that both NP and PCB104 appeared to have antiestrogenic effects during this phase.

• Fisheries and Aquatic Sciences
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• v.8 no.2
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• pp.76-82
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• 2005

We analyzed the paralytic shellfish poisoning (PSP) toxins of the toxic marine dinoflagellate Alexandrium tamarense collected from Dadaepo and Gaduck-do in Busan and from Sujeong-ri in Jinhae Bay, Korea, in April 2003. We also analyzed the PSP toxin of mussels (Mytilus galloprovincialis) and oysters (Crassostrea gigas) collected around Busan and Jinhae Bay. PSP toxin analyses were conducted by high performance liquid chromatography (HPLC). Fifteen cultured A. tamarense isolates contained 2.78 to 57.47 fmol/cell, with nearly identical toxin profiles: major components C2, GTX4; minor components C1, GTX1, NEO; and trace components GTX2, GTX3, STX. PSP toxin contents were 0 to $492\;\mu{g}$ STXeq/100 g in mussels and 0 to $48\;\mu{g}$ STXeq/100 g in oysters. Mussels at Gijang and Sujeong-ri contained the most PSP toxin contents ($492\;\mu{g}\;STXeq/100\;g\;and\;252\;\mu{g}\;STXeq/100\;g,\;respectively$), exceeding the quarantine level ($80\;\mu{g}$ STXeq/100 g). Their dominant toxin components were C2, C1, GTX2, and GTX3; the minor components GTX1, GTX4, GTX5, and NEO were sporadically detected. Phytoplankton contained 0.774 fmol/L seawater and 1.228 fmol/L seawater at Gijang and Sujeong-ri in April. At that time, Alexandrium cells were present in the water column at Gijang at 2,577 cells/mL and at Sujeong-ri at 6,750 cells/mL. Overall, we found the high and similar PSP toxin contents in AZexandrium isolates and mussels, and a correlation between occurrence of toxic Alexandrium cells in the water column and mussel intoxification. High densities of toxic Alexandrium cells in the water column immediately preceded shellfish intoxification at Gijang and Sujeong-ri in April.

• Fisheries and Aquatic Sciences
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• v.9 no.3
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• pp.107-114
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• 2006

A dermal sarcoma was found in a freshwater, soft-shelled turtle Pelodiscus sinensis. The neoplasm consisted of proliferating fibrous tissue and extended from the dermis. The overlying epidermis was hyperplastic and partially folded. The deeper dermis and hypodermis contained three large, discrete necrotic foci of -10 mm diameter. Numerous eosinophilic granule cells and macro phages surrounded the necrotic areas. A mixed population of cells with nuclear pleomorphism was observed between the papillary layers of vessels. This area also had regions of different histological structures: (l) regularly arranged, spindle-shaped cells with compact nuclei in a fine-fibrillar matrix; (2) haphazardly arranged cells ($\leq$ 23 11m diameter) with ovoid, highly hypertrophic, faintly stained nuclei; and (3) cells (3.6-5.8 11m diameter) with irregularly shaped nuclei and marginal condensed chromatin in a myxomatous matrix. Some mitotic figures, binucleate cells, and multinucleate giant cells of up to 50 11m in length were also found. Flow cytometry of propidium iodide-stained cells yielded different histograms for the normal skin and the skin (primarily epidermis) and fibrous dermis of the tumor, indicating DNA heterogeneity in the dermal portion of the tumor. The ploidy indices for the dermal cells were 1.91 and 0.78, as compared to normal cells.

• Animal cells and systems
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• v.4 no.4
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• pp.381-388
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• 2000

Using a murine T cell hybridoma, activation-induced cell death (AICD) was studied. As an in vitro model system for the AICD, 1 cell hybridoma expressing TCR/CD3 complex was incubated onto the immobilized purified anti-CD3 antibody. The immobilized anti-CD3 antibody induced AICD effectively up to 40%. At 1-100 $\mu$M range of SNP, an exogenous source of nitric oxide (NO), the cell proliferation was not affected, but at 1 mM SNP, cell proliferation was significantly reduced. The AICD of T cell hybridoma was inhibited by exogenous NO at non-cytotoxic concentration, In the cells undergoing AICD, the expressions of caspase-3 and FasL were detected, but not iNOS. Similar result was recognized in the apoptosis induced by dexamethasone, an apoptosis-inducing agent. However, the conversion from the inactive form of caspase-3 (32 kDa) to the active form (17 kDa) was significantly reduced in the cells in AICD induced by anti-CD3 antibody, With the result of increased PARP cleavage in the cells, we propose that another PARP cleavage pathway not involving caspase-3 may function in the anti-CD3 antibody induced AICD in the T cell hybridoma.

• Fisheries and Aquatic Sciences
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• v.5 no.1
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• pp.75-78
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• 2002

The effects of Coehlodinium polykrikoides on the gill of red sea bream, Pagrus major, were examined to clarify the ichthyotoxic mechanisms of this plankton species. The gill of fish exposed to dense blooms over 3,000 cells/mL for 24 h showed severe epithelial separation: a severe edema was found in the secondary lamellar epithelium and interlamellar regions of primary filament. In addition, lipid peroxidation of gill tissue in Coehlodinium-exposed fish was about 2.5 times higher than that of control. The composition of glycoproteins in the gill mucus of Coehlodinium-exposed fish was also changed. These results suggest that the loss of structural integrity of cell membranes in fish gill may be deeply involved in fish death by C. polykrikoides.