• Journal of odor and indoor environment
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• v.16 no.1
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• pp.54-63
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• 2017

The Automobile HVAC system is a habitat for odor-associated fungal communities. We investigated the odor-associated fungal community in an automobile HVAC system using a high-throughput DNA sequencing method. The fungal community structure was evaluated via metagenome analysis. At the phylum level, Ascomycota and Basidiomycota were detected, accounting for 43.41% and 56.49% of the fungal community in the HVAC system, respectively. Columnosphaeria (8.31%), Didymella (5.60%), Davidiella (5.50%), Microxyphium (4.24%), unclassified Pleosporales (2.90%), and Cladosporium (2.79%) were abundant at phylum of Ascomycota and Christiansenia (36.72%), Rhodotorula (10.48%), and Sporidiobolus (2.34%) were abundant at phylum of Basidiomycota. A total of 22 genera of fungi were isolated and identified from the evaporators of the HVAC systems which support fungal growth and biofilm formation. Among them, Cladosporium, Penicillium, Aspergillus, and Alternaria are the most representative odor-associated fungi in HVAC systems. They were reported to form biofilm on the surface of HVAC systems with other bacteria by hypha. In addition, they produce various mVOCs such as 3-methyl-1-butanol, acetic acid, butanoic acid, and methyl isobutyl ketone. Our findings may be useful for extending the understanding of odor-associated fungal communities in automobile HVAC systems.

• Clinical and Experimental Pediatrics
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• v.55 no.6
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• pp.185-192
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• 2012

The prevalence of allergic diseases has increased worldwide, a phenomenon that can be largely attributed to environmental effects. Among environmental factors, air pollution due to traffic is thought to be a major threat to childhood health. Residing near busy roadways is associated with increased asthma hospitalization, decreased lung function, and increased prevalence and severity of wheezing and allergic rhinitis. Recently, prospective cohort studies using more accurate measurements of individual exposure to air pollution have been conducted and have provided definitive evidence of the impact of air pollution on allergic diseases. Particulate matter and ground-level ozone are the most frequent air pollutants that cause harmful effects, and the mechanisms underlying these effects may be related to oxidative stress. The reactive oxidative species produced in response to air pollutants can overwhelm the redox system and damage the cell wall, lipids, proteins, and DNA, leading to airway inflammation and hyper-reactivity. Pollutants may also cause harmful effects via epigenetic mechanisms, which control the expression of genes without changing the DNA sequence itself. These mechanisms are likely to be a target for the prevention of allergies. Further studies are necessary to identify children at risk and understand how these mechanisms regulate gene-environment interactions. This review provides an update of the current understanding on the impact of air pollution on allergic diseases in children and facilitates the integration of issues regarding air pollution and allergies into pediatric practices, with the goal of improving pediatric health.

• Journal of Environmental Science International
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• v.12 no.12
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• pp.1293-1301
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• 2003

A species of facultative photo-organotrophic, purple, non-sulfur bacterium was isolated from the 47 point at west and south coast of Korea in September 2001. Separated 13 samples of changes with red color under 28-32$^{\circ}C$, 3000 lux, anaerobe conditions for 7 days cultivated in basal medium. For pure isolation from 13 samples, we used agar-shake tube method (0.4 ％ agar) and separated 5 strains through 13-repetition test. EGH-24 and EGH-30 was identified as the same strain through the RAPD(Random Amplified Polymorphic DNA)-PCR of strain EGH-9, EGH-13, EGH-23, EGH-24, EGH-30. Four isolates cultivated in synthesis wastewater for wastewater biodegradation test. EGH-24 was selected with efficient wastwater treating strain. Based on the results obtained from morphology, nutrient requirements, major bacteriochlorophyll content, 16S-rDNA phylogenetic analysis, EGH-24 strain may be identified as a new strain of the genus Rhodobacter and named Rhodobacter sp. EGH-24.

• Environmental Mutagens and Carcinogens
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• v.24 no.2
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• pp.79-84
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• 2004

Three synthetic chemicals, benzoyl chloride, 2-propyn-l-ol, and 2-phenoxy ethanol were selected for genotoxicity testing, based on production quantity and available genotoxic data. In our previous report, benzoyl chloride induced chromosomal aberrations in Chinese hamster lung (CHL) fibroblast in vitro with and without metabolic activation, while 2-propyn-l-ol and 2-phenoxy ethanol induced only with metabolic activation. To compare the genotoxicity of chromosome aberration assay, the single cell gel electrophoresis (comet) assay subjected using CHL cells. As a result, statistically significant differences of tail moment values of benzoyl chloride, 2-propyn-1-ol, and 2-phenoxy ethanol were observed compared with control values on almost all concentrations with S9 or without S9 metabolic activation system. This results suggest that genotoxic results of the comet assay and the chromosome aberration assay show correlationship of genotoxicity in the CHL fibroblast. In summary, the positive result of chromosome aberration of benzoyl chloride, 2-propyn-l-ol, and 2-phenoxy ethanol was also induced DNA damages in comet assay with same cell line. Consequently, comet assay will be useful and more accurate tool to detect and to confirm the genotoxicity especially DNA damages in CHL fibroblast.

• Environmental Mutagens and Carcinogens
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• v.24 no.3
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• pp.113-120
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• 2004

Chromium compounds are known human and animal carcinogens. In this study, the effects of sodium chromate on apoptosis and cell cycle were investigated in order to unveil the elements of early cellular responses to the metal. Using Chinese hamster ovary cells(CHO-K1-BH4), we found taht chromium (VI) treatment induced apoptosis in these cells, as signified by nuclear fragmentation, DNA laddering on agarose gel electrophoresis, and an increased proportionof cells with hypodiploid DNA. Preceding these changes, chromium (VI) treatment increased caspase 3 pritease activity and also increased expression of p53 protein, while the level of bcl2 protein was not changed. Coincubation with caspase inhibitor, Z-DEVD-FMK, inhibited chromium-induced apoptosis. In the flow cytometric analysis using propidium iodide fluorescence, an increase of cell population in G2/M phase was shown in cells exposed to at least 160 $\mu\textrm{m}$ of sodium chromate for 72h, form 9.8% for 0$\mu\textrm{m}$ chromium (VI) to 26.4% for 320$\mu\textrm{m}$ chromium(VI). Taken together, these findings suggest that chromium(VI)-induced apoptosis is accompanied by G2/M cell cycle arrest, and that p53-mediated pathway may be involved in positive regulation of G2/M arrest and a concurred apoptosis in CHO cells.

• Journal of Microbiology
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• v.37 no.3
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• pp.141-147
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• 1999

Thirteen transcriptionally-fused carbon starvation mutants, derived from Pseudomonas putida ATCC 12633, were analyzed for their survivability and transcriptional induction profiles upon carbon starvation. One of these mutants, MK114, which exhibited the lowest survivability and the highest induction rate, was selected and further examined under different starvation (nitrogen and phosphate) and stress (osmolarity, H2O2, salts, alcohol, and heat) conditions. Under all tested conditions MK114 induced ${\beta}$-galactosidase activity, implying that the interrupted gene (cst114) is a general starvation and stress response gene. The rate of induction ranged from 2.6-fold for phosphate starvation to 3.7-fold for osmotic shock. The mini-Tn5 flanking DNA was cloned from the chromosome of MK114. The cloned DNA fragment exhibited carbon starvation activity, indicating that this fragment contains a carbon starvation-related promoter region. This region was partially sequenced. Possible physiological roles of Cst114 in a carbon sensing mechanism and in other stress responses are also discussed.

• Environmental Mutagens and Carcinogens
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• v.18 no.1
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• pp.32-36
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• 1998

It is previously reported that 6-paradol can induce prolonged analgesia in experimental animals. In order to investigate the mutagenicity of 6-paradol, Ames Samonella/microsome plate assay was carried out with Salmonella typhimurium strains, TA 98, TA 100, TA 1535 and TA 1538, 6-Paradol was nonmutagenic in Salmonella typhimurium with and without rat liver microsomal activation. The rec assay with Bacillus substilis strains H 17 $rec^+$ and M 45 $rec^+$ was carried out ot test 6-paradol and other compounds (1-3 mg/disc) for DNA damaging activity, 6-Paradol was also nonmutagenic in DNA damaging activity. The relative size of the inhibition zone for 6-paradol was smaller than that of capsaicin. We have also determined the pathological effects of this compound on the various tissues of rats after administrating(i.p.) with increasing doses of 4, 8, 12, 16 mg/kg at 2 hour intervals and found no significant changes in terms of histology.

• Proceedings of the Korea Society of Environmental Toocicology Conference
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• 2003.05a
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• pp.180-180
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• 2003

Transcript profiling is a particularly valuable tool in the field of steroid receptor biology, as these receptors are ligand-activated transcription factors and therefore exert their initial effects through altering gene expression in responsive cells. Also, an increased awareness of endocrine disrupting chemicals (EBCs) and their potential to affect wildlife and humans has produced a demand for practical screening methods to identify endocrine activity. Here we developed an in-house cDNA microarray, named KISTCHIP-400, with 401 clones, hormone related genes, factors, and ESTs, based on public database and research papers. Theses clones contained estrogen, androgen, thyroid hormone St receptors, sex hormone signal transduction ＆ regulation, c-fos, c-myc, ps2 gene, metabolism related genes etc. And to validate the KISTCHIP-400, we investigated gene expression profiles with reference hormones, 10$\^$-8/ M 17be1a-estradiol, 10$\^$-7/ M testosterone, 10$\^$-7/ M progesterone, and thyroxin in MCF-7 cell line. Although it is in first step of validation, low doses and combinations of EDCs need to be tested. Our preliminary results that indicate the developed microarray may be a useful laboratory tool for screening EDCs and elucidating endocrine disrupting mechanism.

• Korean Journal of Microbiology
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• v.53 no.3
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• pp.216-218
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• 2017

We here provide the complete genome sequence of Bacillus thuringiensis C25, the strain showing antagonistic effects on fungal phytopathogens. The genome comprised of 5,308,062 bp with 35.32% G+C content of a circular chromosome and a plasmid containing 308,946 bp with 32.23% G+C content. The chromosome and plasmid genome included 5,683 protein coding DNA sequences, 107 tRNA and 42 rRNA genes.

• Molecules and Cells
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• v.25 no.2
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• pp.258-264
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• 2008

Deschampsia antarctica is the only monocot that thrives in the tough conditions of the Antarctic region. It is an invaluable resource for the identification of genes associated with tolerance to various environmental pressures. In order to identify genes that are differentially regulated between greenhouse-grown and Antarctic field-grown plants, we initiated a detailed gene expression analysis. Antarctic plants were collected and greenhouse plants served as controls. Two different cDNA libraries were constructed with these plants. A total of 2,112 cDNA clones was sequenced and grouped into 1,199 unigene clusters consisting of 243 consensus and 956 singleton sequences. Using similarity searches against several public databases, we constructed a functional classification of the ESTs into categories such as genes related to responses to stimuli, as well as photosynthesis and metabolism. Real-time PCR analysis of various stress responsive genes revealed different patterns of regulation in the different environments, suggesting that these genes are involved in responses to specific environmental factors.