• Parasites, Hosts and Diseases
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• v.45 no.4
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• pp.301-306
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• 2007

We attempted to identify parasite DNA in the biliary stones of humans via PCR and DNA sequencing. Genomic DNA was isolated from each of 15 common bile duct (CBD) stones and 5 gallbladder (GB) stones. The patients who had the CBD stones suffered from cholangitis, and the patients with GB stones showed acute cholecystitis, respectively. The 28S and 18S rDNA genes were amplified successfully from 3 and/or 1 common bile duct stone samples, and then cloned and sequenced. The 28S and 18S rDNA sequences were highly conserved among isolates. Identity of the obtained 28S D1 rDNA with that of Clonorchis sinensis was higher than 97.6%, and identity of the 18S rDNA with that of other Ascarididae was 97.9%. Almost no intra-specific variations were detected in the 28S and 18S rDNA with the exception of a few nucleotide variations, i.e., substitution and deletion. These findings suggest that C. sinensis and Ascaris lumbricoides may be related with the biliary stoneformation and development.

• Journal of Environmental Health Sciences
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• v.24 no.3
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• pp.92-98
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• 1998

작업장에서 근로자들이 엔진오일 등 각종 오일에 피부가 폭로되었을 때 이것을 쉽게 세척하기 위하여 일반적으로 솔벤트를 사용한다. 그러나 솔벤트를 사용하면 피부를 건조하게 만들 뿐만 아니라 오일에 함유되어 있는 각종 성분들을 피부내에 흡수되는 것을 촉진시킬 수 있어서 이에대한 대처방법이 요구된다. 특히 폐가솔닐엔진오일데는 방향족탄화수소(PAHs)와 같은 물질이 함유되어 있어 체내에 흡수되면 발암물질로 대사되어 표적장기(피부와 폐조직)에서 DNA adducts를 높은 수준으로 형성한다고 알려져 있다. 본 연구에서는 식물기름에서 구할 수 있는 d-라이모닌(Limonene)를 세척제로 사용하여 폐가솔린엔진오일의 폭로로 인하여 형성되는 DNA adducts를 $^{32}P-postlabeling방법으로 분석함으로써 d-라이모닌의 세척효과를 평가하고자 하였다. HDC(ICR) Br 자성마우스의 견갑골 부위에 있는 털을 제거하고 그 부위에 폐가솔린엔진오일을 폭로시키고 1시간과 8시간이 지난 다음에 d-라이모닌으로 각각 세척을 하였다. 마지막 폭로를 마치고 24시간이 지난 다음에 실험동물을 희생시켜 표적장기(폭로된 피부와 폐)에서 시료를 채취하였다. 먼저 시료에서 DNA를 분리하여 가수분해한 다음에 $^{32}P-postlabeling하여 DNA adducts를 분리하였다. 폐가솔린엔진오일만 폭로시킨 그룹의 피부와 폐조직에 형성된 DNA adducts가 각각 30.3$\pm$3.7과 15.7$\pm$2.4로서 대조군(2.5$\pm$1.0과 1.4$\pm$0.4)에 비하여 통계적으로 유의하게 높았고 (p<0.01), 또한 폐조직에서 보다 피부조직에서 통계적으로 유의하게 높았다(p<0.01). 폐가솔린엔진오일을 폭로시킨 후에 d-라이모닌으로 세척한 그룹에서는 피부와 폐조직에 형성된 DNA adducts가 통계적으로 유의하게 감소하였는데(p<0.01), 8시간 보다는 1시간이 지난 다음에 세척한 그룹에서 DNA adducts의 감소현상이 더 크게 나타났다. 결론적으로 피부에 폭로된 폐가솔린 엔진오일을 d-라이모닌으로 세척하면 폐가솔닐엔진오일내에 함유된 발암물질이 체내흡수되는 것이 억제되고, 피부와 폐조직 모두에서 DNA adducts의 형성을 감소시킬 수 있으며, 폐오일이 폭로된 후 빨리 세척하는 것이 더 효과적임을 증명하였다.

• Korean Journal of Ichthyology
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• v.34 no.3
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• pp.208-217
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• 2022

We wanted to develop a real-time PCR assay capable of detecting Liobagrus obesus in environmental DNA (eDNA) extracted from freshwater samples using a pair of species-specific primers and probe for the endangered fish, L. obesus. The species-specific primers and probe were designed in consideration of single nucleotide polymorphisms between 65 species of freshwater fish living in the Republic of Korea within the cytochrome b (cytb) gene of mitochondrial DNA. The species-specific primers and probe, in the real-time PCR assay, showed high specificity as only the L. obesus genomic DNA (gDNA) was found to be positive in the specificity verification using 65 species gDNA of freshwater fish in the Republic of Korea. In addition, in the detection limit analysis using the serial dilution concentrations of L. obesus gDNA, it was found that it was possible to detect up to 0.2 pg, showing high sensitivity. Afterwards, using the species-specific primers and probe, real-time PCR assay was performed on freshwater samples obtained from 8 stations in the mid-upper basin of Geum River. As a result, the cytb gene of L. obesus was detected in total 5 stations including all 3 stations where this species was collected at the time of field survey. Therefore, the species-specific primers and probe developed in present study, and the real-time PCR assay using them, can accurately detect the cytb gene of L. obesus from eDNA samples, which can be utilized to monitor the existing habitats of this species and to discover potential new habitats.

• Journal of Microbiology and Biotechnology
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• v.27 no.4
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• pp.808-815
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• 2017

We demonstrated the quantitative detection of a toxin-producing Microcystis aeruginosa (M. aeruginosa) strain with the laboratory protocol of the NanoGene assay. The NanoGene assay was selected because its laboratory protocol is in the process of being transplanted into a portable system. The mcyD gene of M. aeruginosa was targeted and, as expected, its corresponding fluorescence signal was linearly proportional to the mcyD gene copy number. The sensitivity of the NanoGene assay for this purpose was validated using both dsDNA mcyD gene amplicons and genomic DNAs (gDNA). The limit of detection was determined to be 38 mcyD gene copies per reaction and 9 algal cells/ml water. The specificity of the assay was also demonstrated by the addition of gDNA extracted from environmental algae into the hybridization reaction. Detection of M. aeruginosa was performed in the environmental samples with environmentally relevant sensitivity (${\sim}10^5$ algal cells/ml) and specificity. As expected, M. aeruginosa were not detected in nonspecific environmental algal gDNA over the range of $2{\times}10^0$ to $2{\times}10^7$ algal cells/ml.

• Molecular & Cellular Toxicology
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• v.2 no.1
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• pp.11-14
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• 2006

In this study we attempted to develop a novel genomic method to selectively isolate target functional microbial genomes from environmental samples. For this purpose, stable isotope probing (SIP) was applied in selectively isolating organic pollutant-assimilating populations. When soil microbes were fed with $^{13}C-labeled $ biphenyl, biphenyl-utilizing cells were incorporated with the heavy carbon isotope. The heavy DNA portion was successfully separated by CsCl equilibrium density gradient. And the diversity in the heavy DNA was sufficiently reduced, being suitable for the current DNA microarray techniques to detect biphenyl-utilizing populations in the soil. In addition, we proposed a new way to get more genetic information by combining this SIP method with selective metagenomic approach. The increased selective power of these new DNA isolation methods will be expected to provide a good quality of new genetic information, which, in turn, will result in development of a variety of biomarkers that may be used in assessing ecotoxicology issues including the impacts of organic hazards, and antibiotic-resistant pathogens on human and ecological systems.

• International Journal of Industrial Entomology and Biomaterials
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• v.28 no.2
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• pp.71-84
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• 2014

The full-length heat shock protein 88 (HSP88) complementary DNA (cDNA) of Paecilomyces tenuipes Jocheon-1 was obtained by screening the Paecilomyces tenuipes (P. tenuipes) Jocheon-1 Uni-Zap cDNA library and performing 5' RACE polymerase chain reaction (PCR). The P. tenuipes Jocheon-1 HSP88 cDNA contained an open reading frame (ORF) of 2,139-basepair encoding 713 amino acid residues. The deduced amino acid sequence of the P. tenuipe s Jocheon-1 HSP88 cDNA showed 77% identity to Nectria haematococca HSP88 and 45-76% identity to other fungal homologous HSP88s. Phylogenetic analysis and BLAST program analysis confirmed that the deduced amino acid sequences of the P. tenuipes Jocheon-1 HSP88 gene belonged to the ascomycetes group within the fungal clade. The P. tenuipes Jocheon-1 HSP88 also contained the conserved ATPase domain at the N-terminal region. The cDNA encoding P. tenuipes Jocheon-1 HSP88 was expressed as an 88 kilodalton (kDa) polypeptide in baculovirus-infected insect Sf9 cells. Under higher temperature conditions for the growth of the entomopathogenic fungus, mRNA expression of P. tenuipes Jocheon-1 HSP88 was quantified by real time PCR (qPCR). The results showed that heat shock stress induced a higher level of mRNA expression compared to normal growth conditions.

• Smart Structures and Systems
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• v.12 no.1
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• pp.73-95
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• 2013

Nine deoxyribonucleic acid (DNA) sequences were used to functionalize single-walled carbon nanotube (SWNT) sensors to detect the trace amount of methanol, acetone, and HCl in vapor. DNA 24 Ma (24 randomly arranged nitrogenous bases with one amine at each end of it) decorated SWNT sensor and DNA 24 A (only adenine (A) base with a length of 24) decorated SWNT sensor have demonstrated the largest sensing responses towards acetone and HCl, respectively. On the other hand, for the DNA GT decorated SWNT sensors with different sequence lengths, the optimum DNA sequence length for acetone and HCl sensing is 32 and 8, separately. The detection of methanol, acetone, and HCl have identified that DNA functionalized SWNT sensors exhibit great selectivity, sensitivity, and repeatability with an accuracy of more than 90%. Further, a sensor array composed of SWNT functionalized with various DNA sequences was utilized to identify acetone and HCl through pattern recognition. The sensor array is a combination of four different DNA functionalized SWNT sensors and two bare SWNT sensors (work as reference). This wireless sensing system has enabled real-time gas monitoring and air quality assurance for safety and security.

• Environmental Mutagens and Carcinogens
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• v.18 no.2
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• pp.77-82
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• 1998

In order to compare the suppressive effect of galangin on the genotoxicity by N-methyl-N-nitrosourea (MNU) or benzo[a]pyrene B(a)P, in vivo micronycleus test using mouse peripheral blood and in vitro sister chromatid exchange(SCE) test using mouse spleen lymphocytes were performed. MNU or B(a)P-induced micronucleated reticulocytes in vivo was decreased by the simultaneous treatment of galangin. MNU or B(a)P-induced SCEs in vitro was also decreased by the simultaneous treatment of galangin. On the other hand, the determinations of [$^3$H]MNU-induced total DNA binding and methylated DNA were performed to find out the mechanism of action. [$^3$H]MNU-induced total DNA binding was inhibited by the treatment of galangin in calf thymus DNA. HPLC analysis of DNA hydrolysates showed that galangin caused a decrease of 7-methyl guanine and $O^{6}$-methyl guanine in calf thymus DNA. To elucidate the action mechanism of galangin against B(a)P, alteration of B(a)P metabolism was studied. Galangin inhibited B(a)P metabolism in the presence of S-9 mix and decreased B(a)P-DNA binding in calf thymus DNA with S-9 mix.

• Environmental Mutagens and Carcinogens
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• v.22 no.3
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• pp.164-168
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• 2002

Phthalate analogues are a plasticizer and solvent used in industry and were reported to be a potential carcinogen classified in the category of suspected endocrine disruptors. Most common human exposure to these compounds may occur with contaminated food. They may migrate into food from plastic wrap or may enter food from general environmental contamination. Since these substances are not limited to the original products, and enter the environment, they have become widespread environmental pollutants, thus leading to a variety of phthalates that possibly threaten the public health. To determine whether seven phthalate analogues i.e. diallyl phthalate, diisodecyl phthalate, di-n-nonyl phthalate, butyl benzyl phthalate, di-n-octyl phthalate, di-tridecyl phthalate, and dibutyl phthalate, can induce DNA strand breakage that is one of the various factors related to the mechanism of carcinogenicity, the comet assay which has been widely used for the detection and measurement of DNA strand breaks, was conducted in L5178Y mouse lymphoma cells. From these results, seven phthalates revealed dose-dependent decrease of cell viability, however, no remarkable cytotoxicity was observed even at high concentration of 100 $\mu\textrm{g}$/$m\ell$ phthalates. And also, the results showed that the induction of DNA strand breaks by seven phthalates was not significantly different from the control in this study.

• Proceedings of the Polymer Society of Korea Conference
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• 2006.10a
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• pp.353-353
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• 2006

Deoxyribonucelic acid (DNA) molecules have a huge molecular weight so that DNA was reported to be a promising natural polymer to give durable films. Among many applications of DNA, the authors focused their attention on separation membranes derived from DNA because membranes will play an important role in environmental and energy related processes. DNA-polyion complex membranes were prepared from DNA and corresponding polycations. The DNA-polyion complex membranes showed chiral separation ability toward racemic amino acid mixtures.