• Korean Journal of Food Science and Technology
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• v.36 no.6
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• pp.959-967
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• 2004

To screen probiotic lactic acid bacteria with potent adhesive property on human colonic mucosa, colonic mucin-binding assay was introduced. This colonic mucin-binding assay actually measures the binding activity of surface lectin-like protein (SLP) on colonic mucin, and the optimal conditions were examined. The optimal pH for colonic mucin coating on plate wells was 4.8, and ${\times}24,000$ diluted solution of commercially available horseradish peroxidase (HRP) conjugated streptoavidin yielded good results, for rapid screening, $5.0\;{\mu}g/mL$ of biotinylated SLP from lactic acid bacteria was optimal, and optimal scintillation time of 3,3',5,5'-tetramethyl benzidine (TMB) was 10 min. These conditions were useful for both rapid selection and quantitative analysis of lactic acid bacteria that have high adhesion property to human intestinal tract. Among 50 strains of lactic acid bacteria, including 32 type culture strains and 18 isolated strains from infant feces, Lactobacillus species FSB-1 isolated from kimchi showed the highest binding activity to colonic mucin. From taxonomical viewpoints based on morphological study, physico-biochemical study, partial 16S rDNA seguencing, and phylogenetic analysis, L. species FSB-1 was identified as Lactobacillus brevis.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.19 no.4
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• pp.223-231
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• 2014

In order to prevent the spread of non-indigenous aquatic species through the ballast water in commercial ships, International Maritime Organization (IMO) adopted in 2004 the International Convention for Control and Management of Ship's Ballast Water and Sediments. The Convention mandates treatment of ballast water for most transoceanic voyages and its confirmation of treatment is made with plankton live/dead assay. Fluorescein diacetate assay (FDA), which produces bright green light for live phytoplankton, has been a de facto standard method to determine the survival of marine plankton, but its staining efficacy has been in dispute. In the present study, we examined the limitation of FDA, and compared its efficacy with Neutral red (NR) staining, another promising assay and widely used especially for zooplankton mortality. For all phytoplankton species studied in the present study, except Ditylum brightwellii, the staining efficiency was <50% with FDA. The green FDA fluorescence interfered with phytoplankton autofluorescence in most samples. In contrast, NR assay stained over 90% of both phytoplankton and zooplankton species tested in this study. FDA assay also showed that green FDA fluorescence rapidly faded when phytoplankton cells were exposed to microscope light. Both FDA and NR assay were negative on formalin-killed individuals of both phytoplankton and zooplankton species. Our results suggest that NR assay is more effective for determining the survival of marine plankton and can be applied to test the efficacy of ballast water treatment.

• Proceedings of the Korean Nuclear Society Conference
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• 2001.05a
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• pp.354-354
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• 2001

• Environmental Mutagens and Carcinogens
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• v.21 no.2
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• pp.89-94
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• 2001

Recently, single cell gel electrophoresis, also known as comet assay, is widely used for the detection and measurement of DNA strand breaks in vitro and in vivo in many toxicological fields such as radiation exposure, human monitoring and toxicity evaluation. As well defined, comet assay is a sensitive, rapid and visual method for the detection of DNA strand breaks in individual cells. Briefly, a small number of damaged cells suspended in a thin agarose gel on a microscope slide were lysed, unwinded, electrophoresed, and stained with a fluorescent DNA binding dye. The electric current pulled the charged DNA from the nucleus such that relaxed and broken DNA fragments migrated further. The resulting images which were subsequently named for their appearance as comets, were measured to determine the extent of DNA damages. However, some variations could be occurred in procedures, laboratories's conditions and kind of cells used. Hence, to overcome and to harmonize these matters in comet assay, International Workshop on Genotoxicity Test Procedure (IWGTP) was held with several topics including comet assay at Washington D.C. on March, 1999. In spite of some consensus in procedures and conditions in IWGTP, there are some problems still remained to be solved. In this respect, we attempted to set the practical optimal conditions in the experimental procedures such as lysis, unwinding, electrophoresis and neutralization conditions and so on. First of all, we determined optimal lysis and unwinding time by using 150 $\mu$M methyl methanesulfonate (MMS) which is usually used concentration. And then, we determined optimal positive control concentrations of benzo(a)pyrene (BaP) and MMS in the presence and absence of S9 metabolic activation system, respectively.

• Environmental Mutagens and Carcinogens
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• v.16 no.1
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• pp.6-12
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• 1996

To investigate the clastogenicity of taxol and its precursor, 10-aleacetyl baccatin III, we performed chromosomal aberration assay with chinese hamster lung cells in vitro. The IC$_{50}$ values of taxol and 10-deacetyl baccatin III were determined as $1/16 \times 10^{-4}$ M (5.34 $\mu$g/ml) and $1 \times 10^{-2}$ M (560 $\mu$g/ml) in MTT assay, respectively. It means that the cytotoxicity of taxol revealed 100 times more cytotoxic than 10-deacetyl baccatin III in chinese hamster lung cell line. Nevertheless the strong positive genetic toxicity of taxol in the bone marrow micronucleus assay in vivo which was recently reported, we observed weak positive clastogenicity of taxoi only in the absence of metabolic activation system in the concentration ranges used in this experiment. Moreover, to clarify the involvement of metabolic fate of taxol because of its strong positive result in vivo, 10-deacetyl baccatin III which is a precursor in taxol synthesis, also subjected in chromosomal aberration assay in vitro. However, we observed no clastogenicity of 10-deacetyl baccatin III in this experiment. From above results, it was suggested that the esterification at C-13 appears to be relative for its genetic toxicity in chromosome aberration using chinese hamster lung cell in vitro.

• The Journal of Korean Medicine Ophthalmology and Otolaryngology and Dermatology
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• v.29 no.3
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• pp.95-105
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• 2016

Objectives : Allergic diseases have a various symptoms of hyperresponsiveness and recently hyperresponsive reaction in the chronic phase is reported as the important mechanisms. Cheonggisan(CGS) is used in oriental clinics for curing various skin diseases due to effect of controlling of pruritus. There have been studies on the anti-allergic effect and anti-inflammatory effect of CGS, but there had no study of anti-allergic effects in allergic late inflammation of CGS, so we aimed to find out the effects of CGS in allergic late inflammation in our study.Methods : To investigate the anti-allergy effect and anti-inflammatory effect of CGS, RAW 264.7 macrophage cells and CSG water-extracts were used. Cytotoxic effect of CSG was examined by MTT assay, an oxidative product of NO was measured in the culture medium by the Griess reagent assay. The level of prostaglandin E2(PGE2) was measured by competitive enzyme-linked immunoassay. Cytokine(PGE2, IL-1β, IL-6, TNF-α) was measured by Bio-Plex suspension assay system and quantitative multiplexed cytokine/chemokine assay.Results : We investigated that there was no cytotoxic effect of CGS water-extract at any levels of concentration on RAW 264.7 macrophage cells by MTT assay. CGS water-extracts significantly suppressed the levels of the inflammatory mediators such as NO and PGE2, cytokine of IL-1β, TNF-α at the level of 400 ㎍/㎖ CGS concentration. But there was no significant effect on IL-6 production suppression.Conclusions : These results suggest that CSG water-extract has and anti-inflammatory effects in allergic reaction. These properties may contribute to the allergic diseases and inflammatory related disease care.

• Toxicological Research
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• v.20 no.1
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• pp.43-47
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• 2004

In order to investigate the safety of a water extract (ADP) of 1 : 1 mixture of Anemarrhena rhizoma and Phellodendron cortex for alleviating benign prostate hyperplasia, genotoxicity studies in bacterial and mammalian cell assay systems, namely, the Ames bacterial reverse mutation and chromosomal aberration assays were performed. As shown by the results of the Ames bacterial reversion assay, ADP in the range of 625-5000 $\mu\textrm{g}$/plate did not induce mutagenicity in Salmonella typhimurium TA 98, TA 100, TA 1535 and TA 1537 strains in the absence or in the presence of S9 (the microsomal fraction of rat liver homogenate) metabolic activation. The $IC_{50}$ (50% cell growth inhibition concentration) values of ADP for the chromosomal aberration assay were determined; these were 2425 $\mu\textrm{g}$/ml in the absence and 8126 $\mu\textrm{g}$/ml in the presence of S9 metabolic activation in Chinese hamster lung (CHL) fibroblast cell culture. No chromosomal aberration was observed in CHL cells treated with ADP at 2425, 1212.5 and 606.25 $\mu\textrm{g}$/ml in the absence, or at 8126, 4063 and 2031.5 $\mu\textrm{g}$/ml in the presence of S9 metabolic activation. These results show that under the conditions used, ADP does not harmfully affect the bacterial or mammalian cell system at the gene level.

• Journal of Veterinary Science
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• v.22 no.4
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• pp.56.1-56.10
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• 2021

Background: Fluorescent antibody virus neutralization (FAVN) test is a standard assay for quantifying rabies virus-neutralizing antibody (VNA) in serum. However, a safer rabies virus (RABV) should be used in the FAVN assay. There is a need for a new method that is economical and time-saving by eliminating the immunostaining step. Objectives: We aimed to improve the traditional FAVN method by rescuing and characterizing a new recombinant RABV expressing green fluorescent protein (GFP). Methods: A new recombinant RABV expressing GFP designated as ERAGS-GFP was rescued using a reverse genetic system. Immuno-fluorescence assay, peroxidase-linked assay, electron microscopy and reverse transcription polymerase chain reaction were performed to confirm the recombinant ERAGS-GFP virus as a RABV expressing the GFP gene. The safety of ERAGS-GFP was evaluated in 4-week-old mice. The rabies VNA titers were measured and compared with conventional FAVN and FAVN-GFP tests using VERO cells. Results: The virus propagated in VERO cells was confirmed as RABV expressing GFP. The ERAGS-GFP showed the highest titer (10^8.0 TCID₅₀/mL) in VERO cells at 5 days post-inoculation, and GFP expression persisted until passage 30. The body weight of 4-week-old mice inoculated intracranially with ERAGS-GFP continued to increase and the survival rate was 100%. In 62 dog sera, the FAVN-GFP result was significantly correlated with that of conventional FAVN (r = 0.95). Conclusions: We constructed ERAGS-GFP, which could replace the challenge virus standard-11 strain used in FAVN test.

• Journal of Veterinary Science
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• v.23 no.4
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• pp.51.1-51.10
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• 2022

Background: Due to the unavailability of an effective vaccine or antiviral drug against the African swine fever virus (ASFV), rapid diagnosis methods are needed to prevent highly contagious African swine fever. Objectives: The objective of this study was to establish the ladder-shape melting temperature isothermal amplification (LMTIA) assay for the detection of ASFV. Methods: LMTIA primers were designed with the p72 gene of ASFV as the target, and plasmid pUC57 was used to clone the gene. The LMTIA reaction system was optimized with the plasmid as the positive control, and the performance of the LMTIA assay was compared with that of the commercial real-time polymerase chain reaction (PCR) kit in terms of sensitivity and detection rate using 200 serum samples. Results: Our results showed that the LMTIA assay could detect the 10⁴ dilution of DNA extracted from the positive reference serum sample, which was the same as that of the commercial real-time PCR kit. The coincidence rate between the two assays was 100%. Conclusions: The LMTIA assay had high sensitivity, good detection, and simple operation. Thus, it is suitable for facilitating preliminary and cost-effective surveillance for the prevention and control of ASFV.

• Journal of Life Science
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• v.15 no.5 s.72
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• pp.779-782
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• 2005

Cell-free expression is a powerful tool for rapid protein analysis, enabling an efficient identification of gene without cumbersome procedure of transformation and cell culture. Epoxide hydrolase (EH) gene of Rhodotorula glutinis was simply amplified by PCR, and the resultant gene was expressed in vitro using a coupled Transcription/translation system. The cell-free expressed EH protein mixture exhibited the enantioselective hydrolysis activity toward (R)-styrene oxide, representing that cell-free protein synthesis system can be used for the rapid expression of an enantioselective enzyme for an efficient identification of the chiral activity.