• Journal of Life Science
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• v.25 no.4
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• pp.473-480
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• 2015

The endoplasmic reticulum (ER) in the eukaryotic cells is the first compartment in the secretory pathway. Almost secretory proteins and membrane proteins are secreted through the ER, in which post-translational modifications occur via diverse signals from the ER lumen to the cytoplasm and nucleus. Only then are correctly-folded proteins secreted to the outside cells. Unfolded proteins that accumulate in the ER cause a kind of intracellular stress, ER stress, and activate an unfolded protein response (UPR) system. The 3 major transducers of the UPR are inositol requiring 1 (IRE1), PKR-like ER kinase (PERK) and activating transcription factor 6 (ATF6), all of which are ER transmembrane proteins. Recently, novel types of a new ATF6 family have been identified. Those commonly have an ER-transmembrane domain, a transcription-activation domain and a basic leucine zipper (bZIP) domain―Luman, OASIS, BBF2H7, CREBH and CREB4. Each factor functions by regulating the UPR in specific organs and tissues. Although the detailed molecular mechanisms of OASIS family members are unknown, in this study we comprehensively introduce these molecular signals.

• Journal of the Korean Society of Food Science and Nutrition
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• v.42 no.9
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• pp.1467-1474
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• 2013

To develop a starter culture system for the fermentation of mukeunji, we introduced lactic acid bacteria and yeast isolated from mukeunji into kimchi fermentation as a single or a mixed culture. On evaluating mukeunji flavor, we found that the mixed starter kimchi prepared with two strains, ML17 and MY7, gave the best sensory score. These strains were identified as Lactobacillus (Lb.) curvatus ML17 and Saccharomyces (S.) servazzii MY7 by molecular identification method. The fermentative characteristics of starter kimchi were investigated by measuring changes in the physicochemical and microfloral characteristics during the fermentation. The decrease in pH and increase in acidity in the starter kimchi were faster compared to respective values of control kimchi. There was a gradual decrease in hardness of starter kimchi, which was still slow compared to hardness decrease in control kimchi. Microbial analysis of starter kimchi revealed that Lb. curvatus ML17 and S. servazzii MY7 were the dominant organisms during the entire fermentation period. The lactic acid and citric acid contents of starter kimchi were higher than those of the control kimchi after 90 days of fermentation. By sensory evaluation, the starter kimchi scored higher in appearance, mukeunji flavor, sourness, carbonated flavor, savory taste, texture, and overall acceptability, but lower in off-flavor than the control kimchi.

• Journal of Life Science
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• v.12 no.3
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• pp.250-255
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• 2002

Fluorescent species-specific DNA probe (AT1) of toxic dinoflagellate Arexandrium tamarense was tested on several other species, on comparison of binding activity at different preservatives for fixation of the cells, at different culture age and estimation of cell density by light microscope or epifluorescent microscope using whole cell hybridization. Th AT1 probe specifically bound to Alexandrium tamarense, whereas it did not bind to other phytoplankton, in particular Alexandrium catenella, morphologically similar to Alexandrium tamarense, could not react to AT1 probe. When cells were fixed with all three preservatives, labeling cells of Alexandrium tamarense emitted strong fluorescent signal intensity. In addition, regardless culture days, binding activity with AT1 probe was strong. The tell densities estimated by epifluorescent microscope were than those estimated by light microscope. The enumeration and identifying of Arexandriurn tamarense using DNA probe method will be contributed to a new biotoxin monitoring and prediction system in field.

• Korean Journal of Heritage: History & Science
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• v.43 no.3
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• pp.4-25
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• 2010

This study was carried out on scientific conservation treatment based on material characteristics, provenance interpretation, and deterioration diagnosis for seven-storied Jungwon Tappyeongri stone pagoda in Chungju. As a result, main rock of the pagoda is biotite granite with magnetite-series (average $5.86{\times}10^{-3}$ SI unit), containing partly basic xenolith, pegmatite veinlet and feldspar phenocryst. As a result of the provenance presumption of the host rock, a rock around the Songgang stream was identified the same origin. Therefore the rock is appropriate for materials of the pagoda restoration. The deterioration assessment suggested that the pagoda was seriously exfoliated (2.7 to 5.5%), discolored (39.8 to 58.9), and contaminated with repair materials (3.5 to 9.4%), and bioorganisms (19.3 to 24.4%). Accordingly, conservation treatment was carried out based on preliminary investigation for stable conservation of the pagoda. Overall processes were sequentially proceeded by restoration of the replacement stone, cleaning, joining and consolidation. This study sets up an integrated conservation system from preliminary investigation to conservation treatment of the pagoda. Also, the study will contribute for establishing the future-oriented customized conservation treatment.

• Korean Journal of Clinical Laboratory Science
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• v.55 no.4
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• pp.244-252
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• 2023

The timeliness and accuracy of test results are crucial factors for clinicians to decide and promptly administer effective and targeted antimicrobial therapy, especially in life-threatening infections or when vital organs and functions, such as sight, are at risk. Further research is needed to refine and optimize matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS)-based assays to obtain accurate and reliable results in the shortest time possible. MALDI-TOF MS-based bacterial identification focuses primarily on techniques for isolating and purifying pathogens from clinical samples, the expansion of spectral libraries, and the upgrading of software. As technology advances, many MALDI-based microbial identification databases and systems have been licensed and put into clinical use. Nevertheless, it is still necessary to develop MALDI-TOF MS-based antimicrobial-resistance analysis for comprehensive clinical microbiology characterization. The important applications of MALDI-TOF MS in clinical research include specific application categories, common analytes, main methods, limitations, and solutions. In order to utilize clinical microbiology laboratories, it is essential to secure expertise through education and training of clinical laboratory scientists, and database construction and experience must be maximized. In the future, MALDI-TOF mass spectrometry is expected to be applied in various fields through the use of more powerful databases.

• Korean Journal of Microbiology
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• v.43 no.4
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• pp.325-330
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• 2007

RNase E is an essential Escherichia coli endoribonuclease that plays a major role in the decay and processing of a large fraction of RNAs in the cell and expression of N-terminal domain consisted of 1-498 amino acids (N-Rne) is sufficient to support normal cellular growth. By utilizing these properties of RNase E, we developed a genetic system to screen for amino acid substitutions in the catalytic domain of the protein (N-Rne) that lead to various phenotypes. Using this system, we identified three kinds of mutants. A mutant N-Rne containing amino acid substitution in the S1 domain (I6T) of the protein was not able to support survival of E. coli cells, and another mutant N-Rne with amino acid substitution at the position 488 (R488C) in the small domain enabled N-Rne to have an elevated ribonucleolytic activity, while amino acid substitution in the DNase I domain (N305D) only enabled N-Rne to support survival of E. roli cells when the mutant N-Rne was over-expressed. Analysis of copy number of ColEl-type plasmid revealed that effects of amino acid substitution on the ability of N-Rne to support cellular growth stemmed from their differential effects on the ribonucleolytic activity of N-Rne in the cell. These results imply that the genetic system developed in this study can be used to isolate mutant RNase E with various phenotypes, which would help to unveil a functional role of each subdomain of the protein in the regulation of RNA stability in E. coli.

• Korean Journal of Clinical Laboratory Science
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• v.49 no.3
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• pp.279-284
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• 2017

The results of rapid antimicrobial susceptibility test (AST) in blood cultures were obtained by inoculating the bacteria directly into the VITEK MS and the VITEK 2 systems without subculturing in the blood culture positive medium. The obtained results were compared with the results using a standard method to evaluate their reliability and accuracy. The direct AST results in blood culture positive specimens were 97.9% (1,936/1,978), consistent with the standard AST results. Gram-positive bacteria showed a concordance rate of 97.2% (1,051/1,081), a very major error rate of 0.5% (5/1,081), a major error rate of 0.1% (1/1,081), and a minor error rate of 2.2% (24/1,081). Staphylococcus epidermidis was the main cause of discordance, and gentamicin (N=9) and fusidic acid (N=8) showed high errors. The overall concordance rate and minor error among the Gram-negative bacteria were 98.6% (885/897) and 1.4% (12/897), respectively. Escherichia coli and Pseudomonas aeruginosa were the major causative bacteria of Gram-negative bacteria. Among them, amoxicillin/clavulanic acid (N=3) showed high error. Direct AST met the CLSI criteria and shortened the reporting time by 24 hours; however, we found that there was a need to perform an addition test via disk diffusion for antimicrobials with very large errors. These results suggest that the method of direct AST in blood culture positive medium may be very useful in efficiently treating patients.

• Food Science and Preservation
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• v.14 no.1
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• pp.35-41
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• 2007

As the consumption of environmentally friendly agricultural products increases, food safety is at the forefront of public health concerns. We analyzed the biological hazards of 26 species of leaf vegetables and 4 species of fruit according to types of cultivation (conventional or organic filming) and distribution system (giant retailers or organic food stores) using various culture media, automatic bacterial identification systems, and microscopy, Total bacterial count of unwashed agricultural product ranged from $5.2{\times}10^{3}\;to\;1.5{\times}10^{5}\;CFU/mL$ (from 0.1 g of agricultural products), and the average count dropped 25-fold (range, 8-60-fold) after water washing. Microbial levels of washed organic agricultural products were $6.0{\times}10^{2}-1.9{\times}10^{4}\;CFU/mL$, and were not significantly different f개m the microbial loads on conventionally farmed produce. There was no significant difference in bacterial count from agricultural produce purchased from giant retailers or organic food stores. Total microbial count of Chinese cabbage, welsh onion, red chicory and kale were comparatively high, and Enterobacter cloacae was isolated most frequently. Parasites were detected in agricultural products purchased from conventional farm products in the stores of giant retailers, and in organic food stores, and parasite prevalence was especially high in Chinese cabbages and welsh onion. The study indicated that cultivation methods and distribution systems did not cause significant differences in biological contamination levels of agricultural produce. Some vegetables and fruits were highly contaminated effective sanitizing methods to reduce these biological hazards are needed.

• The korean journal of orthodontics
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• v.28 no.4 s.69
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• pp.611-626
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• 1998

Cytokines are intercellular peptide mediators that regulate homeostasis and host defense reactions in living body. Of the diversity of cytokines in terms of biological accomplishment, interleukin $1-{\beta}$($IL-1{\beta}$) and tumor necrosis factor(TNF) are the most conspicuous cytokines with a wide variety of effects on cells involved in inflammatory and immune responses, and likely to be involved in the inflammatory pathogenesis of oral tissue as well. The present study was designed to explicate the role of $IL-1{\beta}$ on inflammatory revelation of oral tissues in mice biochemically. In the Induced arthritis by injection of 10${\mu}g$ LPS shown the relaese of 0.93 ${\mu}g$ $IL-1{\beta}$/joint with a peak at at 4-5 h. and diminished at 24t and the release of $TNF_{\alpha}$ of 1.25 ${\mu}g$/joint with a peak at 2-3h and diminished at 6h. After injection of th $IL-1{\beta}$ into the joint, the mumber of leucocytes proliferated with a peak at 4-5h and diminished at 36h and the loss of proteoglycan showed with maximum at 15-30h. After injection of $IL-1{\beta}$ into the oral tissue, cycloosygenase metabolites ($PGE_2$) accumulated in the oral tissue with dose dependant. These elucidated $IL-1{\beta}$ to be inflammatory mediator in the early phase of its pathogenesis. Intraoral injection of recombinant $IL-1{\beta}$ induced the proliferation of leukocytes in situ. $IL-1{\beta}$ took an pertinent part in the development of inflammation and the succession of cellular infiltration. The results exemplify that $IL-1{\beta}$ plays a significant role in mediating inflammatory response induced by LPS in oral tissue, the inflammatory response is regulated by $IL-1{\beta}$ at an acute phase of pathogenesis.

• Journal of Food Hygiene and Safety
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• v.27 no.4
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• pp.366-374
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• 2012

Recently pathogenic E. coli is one of the main foodborne pathogens resulting in many patients in Korea. To understand the characteristics of pathogenic E. coli outbreaks in Korea, the epidemiological investigation reports of pathogenic E. coli outbreak in 2009 (41 reports) and in 2010 (27 reports) were collected in the web site of the Korea Centers for Disease Control and Prevention, reviewed and analysed in this study. The main places of the pathogenic E. coli outbreaks were food catering service area (64.8%) and restaurants (25.0%). The main type of the pathogens were EPEC (44.7%) and ETEC (34.2%). EAEC and EHEC was responsible for 10.5 and 9.2%, respectively. Eight of 68 outbreak cases were caused by more than 2 types of pathogenic E. coli which implicates the complicated contamination pathways of pathogenic E. coli. The incidence rate of pathogenic E. coli was $33.6{\pm}30.5%$ and the main symptoms were diarrhea, stomach ache, nausea, vomiting, and fever etc. The two identified food sources were identified as frozen hamburger pattie and squid-vegetable mixture. To improve the food source identification by epidemiological investigation, food poisoning notification to the agency should not be delayed, whole food items attributed the outbreak should be collected and detection method of the various pathogenic E. coli in food has to be improved. In conclusion, the characteristics between the EHEC outbreaks in the western countries and the EPEC or ETEC outbreaks in Korea needs to be distinguished to prepare food safety management plan. In addition, the development of the trace back system to find the contamination pathway with the improved detection method in food and systemic and cooperative support by the related agencies are necessary.