• Restorative Dentistry and Endodontics
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• v.33 no.6
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• pp.537-544
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• 2008

Polymerase chain reaction (PCR) can detect bacteria more rapidly than conventional plate counting. However DNA-based assays cannot distinguish between viable and dead cells due to persistence of DNA after cells have lost their vitality. Recently, propidium monoazide (PMA) treatment has been introduced. The purpose of this study is to evaluate the applicability of the PMA treatment and real-time PCR method for cell counting in comparison with plate counting and to evaluate the antibacterial efficacy of 2% CHX on E. faecalis using PMA treatment in combination with real-time PCR. Firstly, to elucidate the relationship between the proportion of viable cells and the real-time PCR signals after PMA treatment, mixtures with different ratios of viable and dead cells were used. Secondly, relative difference of viable cells using PMA treatment in combination with real-time PCR was compared with CFU by plate counting. Lastly, antibacterial efficacy of 2% CHX on E. faecalis was measured using PMA treatment in combination with real-time PCR. The results were as follows : 1. Ct value increased with decreasing proportion of viable E. faecalis. 2. There was correlation between viable cells measured by real-time PCR after PMA treatment and CFU by plate counting until Optical density (OD) value remains under 1.0. However, viable cells measured by real-time PCR after PMA treatment have decreased at 1.5 of OD value while CFU kept increasing. 3. Relative difference of viable E. faecalis decreased more after longer application of 2% CHX.

• Korean Journal of Food Science and Technology
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• v.18 no.5
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• pp.376-381
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• 1986

A hypothesis that Korean home-made fermented soybean products are brown-pigmented in large part by contaminated bacteria is proposed. Twenty six strains of bacteria forming brown pigments in the presence of L-tyrosine were isolated from home-made soybean paste. They were characterized and all were identified as strains of Bacillus subtilis. The isolates produced dark brown to brownish black pigmentation on yeast extract-peptone-glucose agar (YPGA) supplemented with 0.1% L-tyrosine in 72 hours but not on YPGA. They also caused different depress of lighter pigmentation on potato dextrose agar and nutrient agar. When an arbitrarily chosen pigmenting isolate was cultivated in a liquid medium supplemented with L-tyrosine, it began to produce pigments only after cell growth stopped. The tyrosinase enzyme was extracted and the enzyme activity was measured by using L-tyrosine and 3-hydroxytyrosine (L-dopa) as substrates. The crude enzyme preparation porduced pigments at rates of $2.1\;{\times}\;10^{-3}\;and\;5.0\;{\times}\;10^{-3}$ optical density units/min measured at 490㎚ for tyrosine and dopa, respectively. Possible content of L-tyrosine in a soybean paste formula was calculated.

• Journal of Microbiology and Biotechnology
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• v.12 no.4
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• pp.706-709
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• 2002

Bacterial bioluminescence has been known to be a highly valuable reporter system for its potential application as an effective and simple environmental monitoring method for toxic compounds. In this short report, we constructed a streptomycetes-Escherichia coli shuttle vector-containing bioluminescence system and evaluated its potential application for toxic compounds monitoring. The luxAB biolurninescence genes from Vibrio harveyi were cloned into a streptornycetes-E. coli shuttle vector (named pESK004) and functionally expressed in Streptomyces lividans. The recombinant S. lividans containing pESK004 exhibited an optimal biolurninescence at the optical density ($OD_{600\;nm}$) of 0.4-0.5 and aldehyde concentration of 0.005%. When the recombinant bioluminescence streptomycetes was exposed to a toxic compound such as heavy metals, chlorinated phenols, or pesticides, the bioluminescence was decreased proportionally to the concentration of toxic compound in the assay mixture. The $EC_{50}$ (effective concentration to decrease 50% of the bioluminescence prior to exposure) values in the recombinant biolurninescence streptomycetes for mercury, 2,4-dichlorophenol, and malathion were measured at 2.2 ppm, 144.0 ppm, and 82.4 ppm, respectively. The degree of sensitivity and specificity pattern toward these toxic compounds characterized in this recombinant bioluminescence streptomycetes were unique when compared with previously reported bacterial bioluminescence systems, and this revealed that a recombinant bioluminescence streptomycetes might provide an alternative or complementary system for potential environmental monitoring.

• Journal of Physiology & Pathology in Korean Medicine
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• v.20 no.2
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• pp.358-364
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• 2006

To investigate the possible mechanism of Drynariae Rhizoma extracts as a candidate of anti-cancer drug, I examined the effects of Drynariae Rhizoma extracts on the apoptosis of U937 cell line. MTT assay, flow cytometric analysis, SDS-polyacrylamide gel electrophoresis, Western blot analysis, and RT-PCR were performed. Drynariae Rhizoma extracts treatment reduced the cell viablilty of U937 cells in a dose-dependent manner, which was associated with induction of apoptotic cell death. Drynariae Rhizoma extracts treatment also reduced the levels of Bcl-xL anti-apoptotic protein expression and increased the levels of caspase-3, p53, pro-apoptotic protein, in U937 cells. RT-PCR data revealed that the level of bcl-2, bcl-xL mRNA expressions decreased in a dose-dependent manner. These findings suggest that Drynariae Rhizoma extracts may have induction of apoptotic cell death via regulation of several growth regulatory gene products. The abbreviations used are: FBS, fetal bovine serum; PBS, phosphate buffered saline; PI, propidium iodide; OD, optical density; DiOC6, 3,3-dihexyloxa carbcyanine iodide; MTT, 3 [4-5-dimethylthiazol-2-yl] -2-diphenyltetrazolium bromide.

• Food Science of Animal Resources
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• v.30 no.6
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• pp.946-950
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• 2010

This study evaluated the antimicrobial effects of meat processing-related organic acids on Burkholderia thailandensis (Burkholderia pseudomallei surrogate) with different water activities. B. thailandensis KACC12027 (4 log CFU/mL) was inoculated in microwell plates containing tryptic soy broth pH-adjusted to 4, 5, 6, and 7 with ascorbic acid, citric acid, and lactic acid and with water activities adjusted to 0.94, 0.96, 0.98, and 1.0 with NaCl, followed by incubation at $35^{\circ}C$ for 30 h. The optical density (OD) of the samples was measured at 0, 3, 6, 12, 24, and 30 h at 595 nm to estimate the growth of B. thailandensis. Growth of B. thailandensis was observed only at water activity of 1.0. In general, more bacterial growth (p<0.05) was observed at pH 6 than at pH 7, and the antimicrobial effects of the organic acids on B. thailandensis were in the following order: Ascorbic acid > lactic acid > citric acid after incubation at $35^{\circ}C$ for 30 h. These results indicate that organic acids in meat processing-related formulations should be useful in decreasing the risk related to an emerging high risk agent (B. pseudomallei).

• Journal of fish pathology
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• v.34 no.1
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• pp.111-115
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• 2021

Immunoglobulin M (IgM) of sevenband grouper (Epinephelus septemfasciatus) was purified by mannan-binding protein (MBP) affinity column. The purified IgM had an apparent molecular weights of 76 (heavy chain) and 28 (light chain) kDa in sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE). Eight hybridoma clones secreting monoclonal antibodies (mAbs) against sevenband grouper IgM were established. Antibody detection enzyme-linked immunosorbent assay (ELISA) with bovine serum albumin (BSA, antigen) and the 8 mAbs revealed that optical density (OD) values were clearly different between sera from BSA-immunization and non-immunization of sevenband grouper. These results suggest that the produced mAbs in this study are specifically reacted with IgM of sevenband grouper.

• Korean Journal of Poultry Science
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• v.36 no.3
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• pp.231-238
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• 2009

The present study was conducted to investigate the antimicrobial activities of extracts from approximately 40 different traditional Korean medicinal herbs against S. gallinarum and S. epidermidis. The extracts from Schizandra chinensis Baill., Melia azedarach Linn$\acute{e}$, Caesalpinia sappan Linn$\acute{e}$. and Rhus javanica Linn$\acute{e}$. exhibited high antimicrobial activities against S. gallinarum, whereas the extracts from Melia azedarach Linn$\acute{e}$ and Rhus javanica Linn$\acute{e}$. exhibited high antimicrobial growth for S. epidermidis. Minimum inhibitory concentrations (MIC) of Melia azedarach Linn$\acute{e}$, Caesalpinia sappan Linn$\acute{e}$. and Rhus javanica Linn$\acute{e}$. for S. gallinarum were 1.2 mg/mL, whereas MIC of exracts from Rhus javanica Linn$\acute{e}$. extract for S. epidermidis were 0.6 mg/mL. Heat treatment of the extracts from Schizandra chinensis Baill. and Rhus javanica Linn$\acute{e}$. caused a significant reduction in antimicrobial activities against S. gallinarum. but didn't affect antimicrobial activities against S. edidermidis. Alkaline treatment of the extracts from Schizandra chinensis Baill. caused a significant reduction in antimicrobial activities against S. gallinarum, while similar treatment of the extracts from Rhus javanica Linn$\acute{e}$. caused a significant increase in antimicrobial activities against S. edidermidis. Since extracts from Rhus javanica Linn$\acute{e}$. and Caesalpinia sappan Linn$\acute{e}$. exhibited the highest antimicrobial activities, these extracts at the concentrations of 100, 300 or 500 ppm were added and then bacterial growth-inhibiting activities for S. gallinarum and S. epidermidis by these two extracts were further examined. Optical density at 620 nm ($OD_{620}$) after 24 hours incubation in the absence of Rhus javanica Linn$\acute{e}$. extract ranged from 0.30 to 0.45 compared with $OD_{620}$ value ranging from 0.06 to 0.18 in the presence of 100, 300 or 500 ppm of the extract, indicating that growth of all bacteria was significantly inhibited within 24 hours by the addition of at least 100 ppm of Rhus javanica Linn$\acute{e}$ extract. Value of $OD_{620}$ after 24 hours incubation in the absence of Caesalpinia sappan Linn$\acute{e}$. extract ranged from 0.30 to 0.55 compared with $OD_{620}$ value ranging from 0.05 to 0.15 in the presence of 300 or 500 ppm of the extract, indicating that growth of all bacteria was also significantly inhibited within 24 hours by the addition of at least 300 ppm of Caesalpinia sappan Linn$\acute{e}$. extract. In conclusion, these findings suggest that extracts from Rhus javanica Linn$\acute{e}$. and Caesalpinia sappan Linn$\acute{e}$. may play important roles in antimicrobial activities against S. gallinarum and S. epidermidis.

• Restorative Dentistry and Endodontics
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• v.31 no.3
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• pp.192-202
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• 2006

The purpose of this study was to examine the viability of PDL cells in rat molars by using in vivo MTT assay, which was used to compare fast cryopreservation group by liquid nitrogen $(-196^{\circ}C)\;with\;4^{\circ}C$ cold preservation group. A total of 74 Sprague-Dawley white female rats of 4 week-old with a body weight of 100 grams were used. The maxillary left and right, first and second molars were extracted as atraumatically as possible under ketamine anesthesia. Ten teeth of each group were divided as six experimental groups depending upon the preservation. Cryopreservation groups were Group 1 (5% DMSO 6% HES in F medium) Group 2 (10% DMSO in F medium), Group 3 (5% DMSO 6% HES in $Viaspan^(R)$). Group 4 (10% DMSO in $Viaspan^(R)$) which were cryopreserved for 1 week and cold preservation groups were Group 5 (F medium) , Group 6 ($Viaspan^(R)$) at $4^{\circ}C$ for 1 week. Immediate extraction group was used as a control. After preservation and thawing, the in vivo MTT assay was processed. Two way ANOVA and Duncan's Multiple Range Test was performed at the 95 % level of confidence, Another 2 teeth of each group were treated as the same manner and frozen sections $10{\mu}m$ thick for microscopic observation. The value of optical density obtained after in vivo MTT analysis was divided by the value of eosin staining for tissue volume standardization. Group 1, 2 had significantly higher optical density than Group 3 and 4 which had the lowest OD value. Group 6 had higher OD value than in Group 5 (P<0.05). Histological findings of periodontal ligament cell, after being stained with MTT solution were consistent with the in vivo MTT assay results. In this study, the groups which were frozen with DMSO as a cryoprotectant and the groups with F medium showed the best results.

• Journal of Biomedical Engineering Research
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• v.34 no.2
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• pp.73-79
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• 2013

Purpose: The purposes of this study were to measure the dose distribution of Photodynamic therapy(PDT) laser with 635 nm wavelength using GafChromic film. Method & Result: We made each output 300 J by changing mW and sec using the laser beam radiation mode such as C.W(Continuous Wave) mode, Pulse mode and Burst Pulse mode and measured the does at 0 mm and 5 mm of distance from optic fiber catheter end to the film, and at 5 mm distance by changing the angle of the end of the optic fiber catheter as $0^{\circ}$ and $0.5^{\circ}$. The radiated film was scanned and OD(Optical Density) was compared. And two-dimensional isodose curves were obtained and the consistency of shapes was compared. It was confirmed that there was consistency between optic density and the dose radiated on the film when we radiated GafChromic film by changing distance and angle of 300 J output in each radiation mode coordinating mW and sec. Conclusion: In this study, we could identify the stability according to changes in laser beam modes, changes in output according to distance, changes in uniformity according to angle, and beam profiles using GafChromic film, and we could also get two-dimensional isodose curve. It was found that small change in the distance and angle that is made when optic fiber catheter was contacted on the treatment area did not make big effects on the output of beam and the uniformity of dose, and it was also found that GafChromic film could be utilized for the purpose of QA of PDT laser beam.

• Journal of Plant Biotechnology
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• v.49 no.1
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• pp.61-73
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• 2022

In this study, we developed a reliable and efficient Agrobacterium-mediated genetic transformation system by applying sonication and vacuum infiltration to six chickpea cultivars (ICCV2, ICCV10, ICCV92944, ICCV37, JAKI9218, and JG11) using embryo axis explants. Wounded explants were precultured for 3 days in shoot induction medium (SIM) before sonication and vacuum infiltration with an Agrobacterium suspension and co-cultivated for 3 days in co-cultivation medium containing 100 µM/l of acetosyringone and 200 mg/l of L-cysteine. Responsive explants with putatively transformed shoots were selected using a gradual increase in kanamycin from 25 mg/l to 100 mg/l in selection medium to eliminate escapes. Results showed optimal transformation efficiency at a bacterial density of 1.0, an optical density at 600 nm wavelength (OD₆₀₀), and an infection duration of 30 min. The presence and stable integration of the β-glucuronidase (gusA) gene into the chickpea genome were confirmed using GUS histochemical assay and polymerase chain reaction. A high transformation efficiency was achieved among the different factors tested using embryo axis explants of cv. JAKI 9218. Of the six chickpea cultivars tested, JAKI9218 showed the highest transformation efficiency of 8.6%, followed by JG11 (7.2%), ICCV92944 (6.8%), ICCV37 (5.4%), ICCV2 (4.8%), and ICCV10 (4.6%). These findings showed that the Agrobacterium-mediated genetic transformation system will help transfer novel candidate genes into chickpea.