• Analytical Science and Technology
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• v.16 no.5
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• pp.349-357
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• 2003

The universality of low molecular weight metabolites (i.e. amino acids, steroid hormones) allows rapid and straightforward investigation of biochemistry of genetically un-characterized species. Thus in vivo metabolic profiling of amino acid in combination with multivariate data analysis (metabolomics) offers great potential in comparative biology. In this paper, amino acid profiles in biological fluid (media) were studied by using HPLC/FLD. HPLC procedure for amino acids require the formation of derivatives due to the low absorption of the free compounds. o-Phthalaldehyde (OPA) used in association with a thiol, such as 3-mercaptopropionic acid (3-MPA), is one of the most popular and sensitive reagents, which yield quickly fluorescent iso-indoles at room temperature. To improve unstability of OPA/3-MPA derivatization, we optimized injector programs for fixed injection times. Linear regressions for the standard curves were linear in the range 0.5 - 100.0 ppb, giving correlation coefficents above 0.99. The detection limit were 1.70 pmol(GLU) - 23.81 pmol(SER). It is practically useful when the amount of sample is very low on single cells.

• Korean Journal of Clinical Laboratory Science
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• v.47 no.3
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• pp.125-131
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• 2015

The discovery of activating mutations in EGFR in a subset of lung adenocarcinomas was a major advance in our understanding of lung adenocarcinoma biology, and has led to groundbreaking studies that have demonstrated the efficacy of tyrosine kinase inhibitor therapy. Cytologic specimen procedures have become increasingly popular for obtaining diagnostic material in lung carcinomas. However, frequently the small amount of material or sparseness of tumor cells obtained from cytologic preparations limit the number of specialized studies, such as mutation analysis, that can be performed. In this study we used microdissection to isolate small numbers of tumor cells to assess for EGFR mutations from 76 cytological smear slides of patients with lung adenocarcinomas. We compared our results with previous molecular assays that had been performed on either surgical or cytology specimens as part of the patient's initial clinical work-up. Not only were we able to detect the identical EGFR mutation through the pyrosequencing, but we were also able to consistently detect the mutation from as few as 25 microdissected tumor cells. Furthermore, isolating a purer population of tumor cells resulted in increased sensitivity of mutation detection as we were able to detect mutations from microdissection-enriched cases. Therefore, microdissection can not only significantly increase the number of lung adenocarcinoma patients that can be screened for EGFR mutations, but can also facilitate the use of cytologic samples in the newly emerging field of molecular-based personalized therapies.

• Korean Journal of Clinical Laboratory Science
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• v.50 no.2
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• pp.100-109
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• 2018

The emergence and dissemination of multidrug-resistant (MDR) Acinetobacter baumannii isolates have been reported worldwide, with most of these possessing the ability to form biofilms. Biofilm formation is an important virulence factor associated with the resistance to disinfection and desiccation. This study examined the genetic basis of antimicrobial resistance mechanisms of biofilm-forming A. baumannii clinical isolates. Imaging and quantification of biofilms were performed by a crystal violet assay and 46 biofilm-forming A. baumannii isolates were selected. Subsequently, 16 isolates belonging to different clones were identified using REP-PCR, and detection of the antimicrobial determinants in the isolates was carried out. The 16 isolates included 9 non-MDR and 7 MDR isolates. The mean biomass $OD_{560}$ values of the non-MDR (0.96) and MDR (1.05) isolates differed but this difference was not significant. In this study, most biofilm-forming MDR A. baumannii isolates contained various antimicrobial resistance determinants ($bla_{OXA-23}$, armA, and mutations of gyrA and parC). On the other hand, most biofilm-forming non-MDR A. baumannii isolates did not contain antimicrobial resistance determinants. These results suggest that there is little correlation between the biofilm-forming ability and antimicrobial susceptibility in A. baumannii isolates. In addition, the emergence of MDR A. baumannii clinical isolates is generally caused by mutations of the genes associated with antimicrobial resistance and/or the acquisition of various antimicrobial resistance determinants.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.16 no.3
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• pp.190-196
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• 1983

This experiment was carried out to compare the change of muscle protein compositions, amino acid compositions of muscle protein, and free amino acid compositions by age of the Israeli strain of common carp, Cyprinus carpio nudus. Protein compositions of the muscle were: sarcoplasmic protein $25.8-27.2\%$, myofibrillar protein $62.3-56.2\%$, residual intracellular protein $9.6-13.2\%$ and stroma $2.3-2.9\%$. In between 1 year and 3 years, there were differences as follows; myofibrillar protein in 1 year was much than 3 years, and other proteins in 3 years were much than 1 year. By SDS-polyacrylamide gel electrophoresis, sarcoplasmic protein of the samples in 1 year an 3 years were composed of 11 subunits and 10 subunits, respectively. And appeared 210,000 dalton component in 1 year but did not appeared in 3 years. Myofibrillar protein was composed of 23 subunits in both 1 year and 3 years but the differences of subunits by age were not observed. No differences were observed by age in the composition of myofibrillar protein and residual intracellular protein. Amino acid composition of muscle protein in both 1 year and 3 years were no differences to each other, but the contents of glutamic acid, aspartic acid, lysine were higher than other amino acids. The amount of total free amino acid in 1 year was much than in 3 years.

• Korean Journal of Poultry Science
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• v.38 no.2
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• pp.89-96
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• 2011

The outbreak of Newcastle disease occurred for the first time at a commercial chicken farm near Ulaanbaatar, Mongolia in August 2010. Newcastle disease virus (NDV) obtained from infected chickens in Mongolia was characterized by biological and molecular biological approches. Mongolian NDV isolate killed all of chicken embryos within 60 h in the mean death time assay, indicating virulent for chicken. A genomic region of 695 nts between nts 1055 of the M gene and 508 of the F gene was amplified by RT-PCR and sequenced. The deduced amino acid sequence of the F protein cleavage site was $^{112}RRQKRF^{117}$, which is a typical sequence of velogenic strains of NDV and is agreement with the result of the MDT assay. The sequence of the partial F gene (nts 47 to 435) was used for genotyping by phylogenetic analysis. The phylogenetic analysis showed that the Mongolian isolate was of genotype VII within class II of NDV. Further phylogenetic analysis on the genotype VII strains revealed that the isolates placed in a genetic sublineage of VIId and most closely related with velogenic strains of NDV circulating in Far-east Asian region especially China, suggesting the introduction of velogenic NDV into Mongolia from neighboring countries.

• The Korean Journal of Mycology
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• v.17 no.2
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• pp.66-75
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• 1989

Heterogeneity in antigenic composition of Aspergillus fumigatus isolates from clinical specimens and in antibody response of patients infected with this fungus was investigated by immunoblotting. A considerable quantitative and qualitative difference was found in composition of the culture filtrate antigens derived from a reference strain (ATCC 13073) and 8 clinical isolates of A. fumigatus on SDS-PAGE and immunoblots. The crude CF antigen of a strain AFG7 was selected to identify the serologically reactive and specific components by immunoblotting. Out of more than 36 components separated by electrophoresis, transblotted to nitrocellulose sheet, and reacted with sera that showed a positive reaction to A. fumigatus or other fungal antigens on immunodiffusion tests, merely four or so were found useful to serodiagnosis of aspergillosis. An antigen of 82KD was found most reactive and specific component so as to be contained in the standard preparation. Several other components, for example 11KD, 26KD, 30KD and 31KD, also possessed relatively high reactivity and specificity and seemed to be worth while purifying and characterizing. Antibody binding activity (reactivity) of the antigenic components was clearly shown on immunoblots because some were faintly stained with Coomassie blue but darkly stained on immunoblots, while some others behaved contrary to them. A number of components seemed to carry not only species specific but cross reactive antigenic determinants. Immunoblotting proved very useful to identify serologically reactive and specific components that should be present in the antigen to be employed to the serodiagnosis of aspergillosis.

• The Korean Journal of Zoology
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• v.28 no.3
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• pp.166-178
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• 1985

In order to express hepatitis B surface antigen $(HB_sAg)$ containing pre-surface antigen region in mammalian calls, 2.7 kb DNA fragment containing pre-surface region-$HB_sAg$ gene poly(A) addition site of HBV genome was cloned into simian virus 40(SV 40) based chimeric vector pSVOB. 2.7 kb DNA fragment was derived from pHBVD 107 containing tandem copies of the HBV genome in a head-to-tail arrangement by Bgl II digestion. Construction of the vector pSVOE involved the incorporation of SV40 sequences spanning the viral origin of replication and 72 bp repeats (enhancer) into a pBR 322 derivative lacking sequences which inhibit replication in mammalian cells. Bam HI linker was inserted at the Pvu II site in the proximity of SV40 late promoter of pSVOE and named as pSVOB. To construct the recombinant plasmid pSVBS, pHBVD 107 was digested with Bgl II to isolate 2.7kb DNA fragment and the fragment was ligated into the Bam HI site of pSVOB by ligation. Preliminary result showed that the recombinant plasmid pSVBS produced $HB_sAg$ in the monkey cell producing large T antigen (COS cell).

• Journal of Life Science
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• v.26 no.9
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• pp.1007-1014
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• 2016

A highly efficient, rapid, and reliable multiplex polymerase chain reaction based method for distinguishing ten species of genus Cynoglossus (C. senegalensis, C. abbreviates, C. macrolepidotus, C. arel, C. semilaevis, C. interruptus, C. joyneri, C. lingua, C. robustus, and C. monodi) is described. The species-specific primer sets were designed base on the cytochrome oxidase subunit I gene (1,500 bp). The optimal PCR conditions and primers were selected for ten of Cynoglossus species to determine target base sequences using single PCR. Multiplex PCR using the ten pairs of primers either specifically amplified a DNA fragment of a unique size or failed, depending on each species DNA. The length of amplification fragment of 208 bp for C. senegalensis, 322 bp for C. abbreviates, 493 bp for C. macrolepidotus, 754 bp for C. arel, 874 bp for C. semilaevis, 952 bp for C. interruptus, 1,084 bp for C. joyneri, 1,198 bp for C. lingua, 1,307 bp for C. robustus, and 1,483 bp for C. monodi with the species-specific primers, visualized by agarose gel electrophoresis, allowed perfectly distinction of the Cynoglossus species. The multiplex PCR assay can be easily performed on multiple samples and attain final results in less than 6 hours. This technique should be a useful addition to the molecular typing tools for the tentative identification of Cynoglossus species.

• Journal of Korean Society of Environmental Engineers
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• v.37 no.1
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• pp.45-51
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• 2015

PBDEs (polybrominated diphenyl ehters) are rarely dissolved in water due to their strong hydrophobicity and large molecular mass so not many researches were done in aqueous environment compared to other environmental compartments. However, the mass loading from wastewater treatment plant into aquatic environment, re-suspension from bottom sediment and partitioning from floating particles and colloids may not be negligible. It is, therefore, important but also difficult to investigate PBDEs in water environment. Recent overcoming resolution towards this barrier to monitor hydrophobic organic compounds in aquatic environment is using passive sampling technique like semipermeable membrane device. By using passive sampling, it might be possible to obtain long-term reproducible monitoring result and detect the trace amounts of PBDEs, with controlling fluctuation of surrounding environmental factors during the sampling event. So therefore, this study is purposed to confirm the possibility of using SPMD (semi-permeable membrane device) as water monitoring tool. Grab samples, composite samples and SPMDs were applied in river bank to evaluate the concentration difference and temporal fluctuation by various water sampling method, and to assess the water concentration prediction capability of SPMD for the PBDEs.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.34 no.6
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• pp.672-677
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• 2001

There was an outbreak of food poisoning due to eating well-cooked imported tropical fish, Stromateus stellatus on May, 2000, in Korea. Gastrointestinal symptoms such as diarrhea ($92\%$), nausea ($77\%$), abdominal pain ($54\%$), vomiting ($46\%$) and headache ($23\%$) were experienced within $0.5\~2$ hours (median 1 hour) after eating, Any specific natural toxins were not confirmed concerned to those poisoning, but large amount of abnormal lipid ($23\%$) was found from the muscle such as 1-O-diacyl glyceryl ethers (DAGE), which was consisted of $61.8\%$ of total lipid. The 16:0 ($66.3\%$) and 18:1 ($15.8\%$) alkyl chains were dominant in all alkyl chains of DAGE which were presumed as the causative agent for the diarrheal food poisoning. O1eic acid (18:1) was found as a major fatty acid at the sn-2 or 3 in DAGEs. O-16:0-18:1-18:1 ($16.2\%$),O-16:0-18:1-22:1 ($14.7\%$) and O-18:0-18:1-22:1 ($11.0\%$) were contained as the major molecular species of DAGEs by RI-HPLC.