• Title/Summary/Keyword: Cell-based assay

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Improvement of polymerase chain reaction methods for rapid detection of Listeria monocytogenes in raw milk (원유로부터 Listeria monocytogenes의 신속검색을 위한 종합효소 연쇄반응법의 개선)

  • Yi, Chul-hyun;Son, Won-geun;Kang, Ho-jo
    • Korean Journal of Veterinary Research
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    • v.36 no.1
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    • pp.119-129
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    • 1996
  • The present study was conducted to rapidly detect Listeria monocytogenes in raw milk. Specificity and sensitivity of polymerase chain reaction(PCR) technique, and direct PCR were examinded in raw milk, also were compared the calssical culture methods with PCR technique. This method used a pair of primers based on a unique region in the 16S rRNA sequence of L nomocytogenes. In the PCR specificity tests, each of the 10 strains of L monocytogenes tested gave a single 70-bp band. But the other six Listera spp tested gave negative results. Results of the sensitivity tests showed that as few as 2 CFU of L monocytogenes in pure cultures could be detected with 16S rRNA-based primers, L-1 and L-2. In different PCR cycles, a PCR product was detected with $10^3$ cells of L monocytogenes from 25 cycles to 50 cycles and the concentration of PCR products was cycle-dependent. Raw milk samopes added L monocytogenes cells gave negative results. However, these samplers gave a single 70-bp band by pretreatment of pronase, and PCR products were detected with $10^1$ cells of L monocytogenes. To detemine the most sensitive culture protocol to use in conjunction with the PCR assay, raw milk samples were inoculated with L monocytogenes at concentrations ranging from 1 to $5.7{\times}10^4CFU/ml$. PCR assays from Listeria enrichment broth(LEB) containing raw milk samples added L monocytogene EGD could dtect 10 cells in pronase-pretreated samples without incubation, and 1 cell of L monocytogenes in both 12 hr and 24 hr incubation, respectively. Isolation raw of PCR assays was similar to that of classical culture methods, but required time for detection of L monocytogenes could remarkably be reduced compare to culture methods.

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Development of Fecal Microbial Enzyme Mix for Mutagenicity Assay of Natural Products

  • Yeo, Hee-Kyung;Hyun, Yang-Jin;Jang, Se-Eun;Han, Myung-Joo;Lee, Yong-Sup;Kim, Dong-Hyun
    • Journal of Microbiology and Biotechnology
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    • v.22 no.6
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    • pp.838-848
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    • 2012
  • Orally administered herbal glycosides are metabolized to their hydrophobic compounds by intestinal microflora in the intestine of animals and human, not liver enzymes, and absorbed from the intestine to the blood. Of these metabolites, some, such as quercetin and kaempherol, are mutagenic. The fecal bacterial enzyme fraction (fecalase) of human or animals has been used for measuring the mutagenicity of dietary glycosides. However, the fecalase activity between individuals is significantly different and its preparation is laborious and odious. Therefore, we developed a fecal microbial enzyme mix (FM) usable in the Ames test to remediate the fluctuated reaction system activating natural glycosides to mutagens. We selected, cultured, and mixed 4 bacteria highly producing glycosidase activities based on a cell-free extract of feces (fecalase) from 100 healthy Korean volunteers. When the mutagenicities of rutin and methanol extract of the flos of Sophora japonica L. (SFME), of which the major constituent is rutin, towards Salmonella typhimurium strains TA 98, 100, 102, 1,535, and 1,537 were tested using FM and/or S9 mix, these agents were potently mutagenic. These mutagenicities using FM were not significantly different compared with those using Korean fecalase. SFME and rutin were potently mutagenic in the test when these were treated with fecalase or FM in the presence of S9 mix, followed by those treated with S9 mix alone and those with fecalase or FM. Freeze-dried FM was more stable in storage than fecalase. Based on these findings, FM could be usable instead of human fecalase in the Ames test.

The Effect of Bacillus-Fermented Scutellariae Radix Acupuncture Solution on Chemokine and Growth Factor Production in Mouse Macrophage Stimulated by Lipopolysaccharide (바실러스균 발효황금약침액이 마우스 대식세포의 케모카인 및 생성인자 생성에 미치는 영향)

  • Park, Wan-Su
    • Korean Journal of Acupuncture
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    • v.27 no.3
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    • pp.109-118
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    • 2010
  • Objectives : The purpose of this study is to investigate the effect of Bacillus-fermented Scutellariae Radix acupuncture solution (SB) on chemokine and growth factor production in RAW 264.7 mouse macrophages stimulated by lipopolysaccharide (LPS). Methods : Productions of chemokine and growth factor were measured by High-throughput Multiplex Bead based Assay with Bio-plex Suspension Array System based on xMAP$^{(R)}$ technology. Firstly, cell culture supernatant was obtained after treatment with LPS (1 ${\mu}g$/mL) and SB for 24 hours. Then, it was incubated with the antibody-conjugated beads for 30 minutes. Detection antibody was then added and incubated for 30 minutes. After incubated for 30 minutes, strepavidin-conjugated phycoerythrin (SAPE) was added. After another 30 minutes incubation, the level of SAPE fluorescence was analyzed in Bio-plex Suspension Array System. Results : The results of the experiment are as follows. 1. SB significantly inhibited the LPS-induced production of vascular endothelial growth factor (VEGF), interferon-inducible protein (IP)-10, and granulocyte-colony stimulating factor (G-CSF) at the concentration of 25, 50, 100, and 200 ${\mu}g$/mL in RAW 264.7 cells (P < 0.05). 2. SB significantly inhibited the LPS-induced production of Eotaxin at the concentration of 25, 100, and 200 ${\mu}g$/mL in RAW 264.7 cells (P < 0.05). 3. SB significantly inhibited the LPS-induced production of MIP-$1\alpha$ at the concentration of 25 and 100 ${\mu}g$/mL in RAW 264.7 cells (P < 0.05). Conclusions : These results suggest that SB has immuno-modulatory property related with its inhibition of VEGF, IP-10, G-CSF, and Eotaxin production in macrophages.

Evaluation of physical property and cytotoxicity of resin infiltrant based on a triethylene glycol dimethacrylate (TEGDMA)

  • Min, Ji-Hyun;Roh, Ji-Yeon;Kim, Ki-Rim
    • Journal of Korean society of Dental Hygiene
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    • v.19 no.2
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    • pp.173-181
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    • 2019
  • Objectives: The resin infiltration technique is a promising alternative therapy for arresting the early dental caries. However, there are very few reports on the safety and biocompatibility of this technique. We evaluated various properties of resin infiltrant (RI) based on a triethylene glycol dimethacrylate (TEGDMA).The water sorption (Wsp) and water solubility (Wsl) was assessed. Additionally, the cytotoxicity of RI against both animal and human fibroblast cell lines was investigated. Methods: The RI of the $Icon^{(R)}$, the first product developed for resin infiltration, is mainly composed of TEGDMA in the resin matrix. The Wsp and Wsl for the RI were measured in accordance with ISO 4049 specifications. Fourier-transform infrared spectroscopy (FTIR) was used for analyzing the polymerization before and after curing of RI. The cytotoxicity of RI against the mouse fibroblasts (L929) and human gingival fibroblasts (hTERT-hNOF) was evaluated using MTT [3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide] assay and the data were analyzed using one-way analysis of variance. Results: Wsp and Wsl of the RI specimens were $53.37{\mu}g/mm^3$ and $10.6{\mu}g/mm^3$, respectively. FTIR analysis revealed a slightly higher degree of curing with longer irradiation time. The degree of conversion for RI was high (80.9%) after 40 seconds of light curing. There was a significant decrease in the viability of L929 and hTERT-hNOF cells at RI extraction solution concentrations above 50%, respectively, compared to that in the negative control (p< 0.05). Conclusions: Even though the RI exhibited positive effect on the early prevention of dental caries, the clinicians should also consider the toxicity of RI on periodontal tissues.

Effects of the cathepsin K inhibitor with mineral trioxide aggregate cements on osteoclastic activity

  • Kim, Hee-Sun;Kim, Soojung;Ko, Hyunjung;Song, Minju;Kim, Miri
    • Restorative Dentistry and Endodontics
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    • v.44 no.2
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    • pp.17.1-17.10
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    • 2019
  • Objectives: Root resorption is an unexpected complication after replantation procedures. Combining anti-osteoclastic medicaments with retrograde root filling materials may avert this resorptive activity. The purpose of this study was to assess effects of a cathepsin K inhibitor with calcium silicate-based cements on osteoclastic activity. Methods: MC3T3-E1 cells were cultured for biocompatibility analyses. RAW 264.7 cells were cultured in the presence of the receptor activator of nuclear factor-kappa B and lipopolysaccharide, followed by treatment with Biodentine (BIOD) or ProRoot MTA with or without medicaments (Odanacatib [ODN], a cathepsin inhibitor and alendronate, a bisphosphonate). After drug treatment, the cell counting kit-8 assay and Alizarin red staining were performed to evaluate biocompatibility in MC3T3-E1 cells. Reverse-transcription polymerase chain reaction, tartrate-resistant acid phosphatase (TRAP) staining and enzyme-linked immunosorbent assays were performed in RAW 264.7 cells to determine the expression levels of inflammatory cytokines, interleukin $(IL)-1{\beta}$, IL-6, tumor necrosis $factor-{\alpha}$ ($TNF-{\alpha}$) and prostaglandin E2 (PGE2). Data were analyzed by one-way analysis of variance and Tukey's post hoc test (p < 0.05). Results: Biocompatibility results showed that there were no significant differences among any of the groups. RAW 264.7 cells treated with BIOD and ODN showed the lowest levels of $TNF-{\alpha}$ and PGE2. Treatments with BIOD + ODN were more potent suppressors of inflammatory cytokine expression (p < 0.05). Conclusion: The cathepsin K inhibitor with calcium silicate-based cement inhibits osteoclastic activity. This may have clinical application in preventing inflammatory root resorption in replanted teeth.

Effect of Aucklandia lappa Decne Extract on Antioxidant

  • Lee, Hea-Jin;Lim, Hyun-Ji;Lim, Mi-Hye
    • Journal of the Korean Applied Science and Technology
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    • v.37 no.6
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    • pp.1545-1555
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    • 2020
  • In the present study, we investigated the antioxidant activity of Aucklandia lappa Decne (AL). Cell viability was measured in an MTT assay. Antioxidant effects were evaluated based on total polyphenol/flavonoid contents, ABTS radical scavenging activity, DPPH radical scavenging activity, SOD activity, and ROS content. AL was found not to be toxic at concentrations of 1 ㎍/mL, 10 ㎍/mL, and 100 ㎍/mL, respectively. The phenolic content was higher in AL-D than in AL-E, while the flavonoid content was higher in AL-E than in AL-D. AL-E exhibited higher ABTS radical scavenging activity than AL-D, and the EC50 values for BHA were 217.1 ㎍/mL in AL-D and 180.5 ㎍/mL in AL-E. AL-E also showed the highest DPPH radical scavenging activity. EC50 values for BHA were 114.2 ㎍/mL in AL-D and 95.8 ㎍/mL in AL-E. The SOD-like activity of AL-E was higher than that of AL-D. The EC50 values for ascorbic acid were 48.5 ㎍/mL in AL-D and 72.9 ㎍/mL in AL-E, indicating that both AL extracts have a SOD activity higher than that of ascorbic acid. AL-E reduced relatively more ROS than AL-D. With 100 ㎍/mL AL-E, the reduction level was almost similar to that of dexamethasone. Our results demonstrate that AL have antioxidant effects, and we believe that they could be very valuable as raw materials for anti-aging products, based on their antioxidant activity.

Inhibitory Effects of Collagen Coated Coffee Bean Intake on Skin Aging

  • Lee, In-Ah;Ha, Mi-Ae;Shin, Yong-Wook
    • Journal of People, Plants, and Environment
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    • v.22 no.1
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    • pp.39-52
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    • 2019
  • To evaluate the protective effect of collagen peptide-coated coffee extract on skin aging, cell viability was measured with a MTT assay using cultured CCD-986sk fibroblasts, and its effect on wrinkles in the skin of hairless mice induced by UVB-irradiation was examined. In addition, its effect on procollagen synthesis and anti-oxidative, and its inhibitory activity against collagenase, elastase, tyrosinase and MMP-1 were analysed. After the 30-minute topical treatment, the animals were exposed to UVB irradiation (60-100 mJ/cm2) for 4 weeks and its intensity increased during the period. Under the experimental conditions set in this study, the skin thickness of hairless mice significantly decreased (11.8-21.3%) compared to the control group. Based on these results, the prolonged oral intake of a collagen peptide mixture with coffee is expected to significantly increase the synthesis of procollagen in dermal fibroblasts, thereby contributing to the alleviation of wrinkling and lowered elasticity due to structural damage to the dermal layer caused by UV. The oral intake of collagen-coated coffee contributes to increasing collagen biosynthesis in a dose-dependent manner and alleviates the symptoms of thickened keratin caused by UV irradiation. However, it did not inhibit the enzymes involved in skin aging, whitening, wrinkle improvement, and antioxidation. Based on the these results, it can be concluded that the intake of collagen peptide-coated coffee extract can be utilized as an alternative material for the prevention or treatment of diseases associated with photoaging.

Influence of 10-Methacryloyloxydecyl Dihydrogen Phosphate on Cellular Senescence in Osteoblast-Like Cells

  • Ju Yeon Ban;Sang-Im Lee
    • Journal of dental hygiene science
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    • v.23 no.4
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    • pp.264-270
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    • 2023
  • Background: Resin-based dental materials release residual monomers or other substances from incomplete polymerization into the oral cavity, thereby causing adverse biological effects on oral tissue. 10-Methacryloyloxydecyl dihydrogen phosphate (10-MDP), an acidic monomer containing dihydrogen phosphate and methacrylate groups, is the most commonly used component of resin-based dental materials, such as restorative composite resins, dentin adhesives, and resin cements. Although previous studies have reported the cytotoxicity and biocompatibility in various cultured cells, the effects of resin monomers on cellular aging have not been reported to date. Therefore, this study aimed to investigate the effects of the resin monomer 10-MDP on cellular senescence and inflamm-aging in vitro. Methods: After stimulation with 10-MDP, MC3T3-E1 osteoblast-like cells were examined for cell viability by WST-8 assay and reactive oxygen species (ROS) production by flow cytometry. The protein and mRNA levels of molecular markers of aging were determined by western blotting and RT-PCR analysis, respectively. Results: Treatment with 0.05 to 1 mM 10-MDP for 24 hours reduced the survival of MC3T3-E1 cells in a concentration-dependent manner. The intracellular ROS levels in the 10-MDP-treated experimental group were significantly higher than those in the control group. 10-MDP at a concentration of 0.1 mM increased p53, p16, and p21 protein levels. Additionally, an aging pattern was observed with blue staining due to intracellular senescence-associated beta-galactosidase activity. Treatment with 10-MDP increased the levels of tumor necrosis factor-α, interleukin (IL)-1β, IL-6 and IL-8, however their expression was decreased by mitogen-activated-protein-kinase (MAPK) inhibitors. Conclusion: Taken together, these results suggest that the exposure of osteoblast-like cells to the dental resin monomer 10-MDP, increases the level of cellular senescence and the inflammatory response is mediated by the MAPK pathway.

Production of Monoclonal Antibody against Escherichia coli O157:H7 and Development of Enzyme Linked Immunosorbent Assay (Escherichia coli O157:H7의 단크론성 항체 생산과 효소면역분석법의 개발)

  • Ryu, Hee-Jeong;Kim, Jeong-Sook;Kim, Kyeong-Yeol;Nam, Bo-Ram;Nam, Min-Ji;Shim, Won-Bo;Kim, Nam-Soo;Cho, Yong-Jin;Chung, Duck-Hwa
    • Korean Journal of Food Science and Technology
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    • v.42 no.3
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    • pp.329-334
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    • 2010
  • Escherichia coli O157:H7 causes hemolytic uremic syndrome and hemorrhagic colitis in humans. The objectives of this study were to produce monoclonal antibody(MAb) against E. coli O157:H7 and to develop an enzyme linked immunosorbent assay(ELISA) for the rapid detection of E. coli O157:H7 in agri-stockbreeding. The characterization of MAb produced from hybridoma cell (HKEC 4G8-5) was validated by ELISA and Western blot. The produced MAb was specific to E. coli O157:H7 and showed weak cross-reaction to Staphylococcus aureus. The detection limit of ELISA based on 4G8-5 MAb was $10^5\;cell/mL$. Although the ELISA could not detect E. coli O157:H7 in the meat and sprout samples inoculated with $1{\times}10^1\;cell$/10 g without enrichment, the same samples after enrichment for 6 hr were confirmed to be positive by ELISA. These results indicated that the ELISA combined with short enrichment (6 hr) is useful tool for rapid screening of E. coli O157:H7 in various samples.

The Effect of Antioxidants on Tumor Necrosis Factor Cytotoxicity (종양괴사인자 세포독성에서 항산화제의 효과)

  • Lee, Hyuk-Pyo;Yoo, Chul-Gyu;Lee, Choon-Taek;Kim, Young-Whan;Han, Sung-Koo;Shim, Young-Soo
    • Tuberculosis and Respiratory Diseases
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    • v.46 no.5
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    • pp.636-644
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    • 1999
  • Background : Tumor necrosis factor(TNF) has been considered as an important candidate for cancer gene therapy based on its potent anti-tumor activity. The mechanisms of TNF cytotoxicity are not clearly understood and some has reported that reactive oxygen species(ROS) might be associated with them, but there is controversy about antioxidant effect on TNF cytotoxicity. This study was designed to compare the TNF cytotoxicity after antioxidant pretreatment with that of control to evaluate the role of ROS in the mechanism of TNF cytotoxicity. Method : We compared the TNF cytotoxicies to WEHI164(murine fibrosarcoma cell line) and ME180(human cervix cancer cell line) after antioxidant pretreatment with those of control by MIT(dimethylthiazolyl-diphenyltetrazolium bromide) assay. Results : In the control group, the TNF cytotoxicities were $92.2{\pm}2.8%$(WEHI164) and $59.9{\pm}7.0%$(MEl80). In the TMTU(tetramethyl thiourea) pretreatment group, those were $91.4{\pm}3.7%$ and $74.6{\pm}7.0%$. In the PMZ(promethazine) pretreatment group, those were $90.2{\pm}2.5%$ and $62.5{\pm}5.7%$. In the BHT(butylated hydroxytoluene) pretreatment group, those were $93.2{\pm}1.3%$ and $66.3{\pm}6.1%$. So there was no reduction in TNF cytotoxicity after antioxidants pretreatment. Conclusion : The ROS may not have major role in the mechanisms of TNF cytotoxicity.

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