• Toxicological Research
• /
• v.20 no.2
• /
• pp.101-108
• /
• 2004

The different social reflections about the benefits and the potential risks of genetically modified (GM) crops have evolved with .different reactions in different countries. Many countries including Korea are working toward setting down new guidelines. Korea requires companies to label all food that contains more than 3% GM ingredients. One of the rapid and convenient detection methods of GM ingredients is amplification of the introduced DNAs by polymerase chain reaction (PCR). Many PCR kits for this purpose are commercially available. The objective of this study was to evaluate performance of commercialized GM crop detection kits. The results showed that 6 out of 15 kits tested did not meet the requirements even purposed by the manufacturers themselves in terms of stability, reproducibility, and detection limits, suggesting a potential quality control problem in their design stage or production line. The evaluation also suggests that, although the duplex and triplex detection kits allowed unambiguous detection in a single PCR reaction, the monoplex detection kits were the most sensitive to the detection of GM ingredients. The detection limits also differ between soybean and corn. Results from this study will be useful in the development of sound qualitative tracking systems of GM ingredients for monitoring throughout the cultivation of GM crops, their trans-boundary movement, and food production using GM grains as well as for complying with government guidelines associated with GM crops.

• Journal of Microbiology
• /
• v.44 no.4
• /
• pp.423-431
• /
• 2006

Among 53 Acinetobacter baumannii isolates collected in 2004, nine imipenem-resistant isolates were obtained from clinical specimens taken from patients hospitalized in Busan, Korea. Nine carbapenemase-producing isolates were further investigated in order to determine the mechanisms underlying resistance. These isolates were then analyzed via antibiotic susceptibility testing, microbiological tests of carbapenemase activity, pI determination, transconjugation test, enterobacterial repetitive consensus (ERIC)-PCR, and DNA sequencing. One outbreak involved seven cases of infection by A. baumannii producing OXA-23 ${\beta}-lactamase$, and was found to have been caused by a single ERIC-PCR clone. During the study period, the other outbreak involved two cases of infection by A. baumannii producing IMP-1 ${\beta}-lactamase$. The two clones, one from each of the outbreaks, were characterized via a modified cloverleaf synergy test and an EDTA-disk synergy test. The isoelectric focusing of the crude bacterial extracts detected nitrocefin-positive bands with pI values of 6.65 (OXA-23) and 9.0 (IMP-1). The PCR amplification and characterization of the amplicons via direct sequencing showed that the clonal isolates harbored $bla_{IMP-1}$ or $bla_{oxA-23}$ determinants. The two clones were characterized by a multidrug resistance phenotype that remained unaltered throughout the outbreak. This resistance encompassed penicillins, extended-spectrum cephalosporins, carbapenems, monobactams, and aminoglycosides. These results appear to show that the imipenem resistance observed among nine Korean A. baumannii isolates could be attributed to the spread of an IMP-lor OXA-23-producing clone. Our microbiological test of carbapenemase activity is a simple method for the screening of clinical isolates producing class D carbapenemase and/or class B $metallo-{\beta}-lactamase$, in order both to determine their clinical impact and to prevent further spread.

• Journal of Life Science
• /
• v.21 no.7
• /
• pp.992-996
• /
• 2011

Endophytic fungi were isolated from the roots of plants growing naturally on the island of Dokdo. Plant samples, such as Miscanthus sinensis, Achyranthus japonica and Echinochloa crusgali were isolated from Dongdo, and those such as Honkenya peploides and Artemsia koidzumii were isolated from Seodo. Twenty one strains of endophytic fungi were isolated from these plants. To identify the strains, PCR (polymerase chain reaction) amplification of the partial ITS (Internal Transcribed Spacer) regions was done with universal primers ITS-1 and ITS-4 to determine the nucleotide sequence of the ITS regions. Of the strains isolated from Miscanthus sinensis, 75% were Penicillium sp. and 25% were Aspergillus sp. Fifty five percent of strains isolated from Achyranthus japonica were Penicillium sp., 30% were Aspergillus sp. and 15% were Zygorhynchus sp. Strains isolated from Echinochloa crusgali were Penicillium sp. (50%), Aspergillus sp. (12%), Giberella sp. (13%), Talaromyces sp. (9%) and Umbelopsis sp. (8%). Of the strains isolated from Honkenya peploides, 76% were Penicillium sp. and 24% were Pestalotiopsis sp. Strains isolated from Artemisia koidzumii were Penicillium sp. (81%) and Mucor sp. (19%). As a result of bioassay, Ec-3-1 strain isolated from Echinochloa crusgalli showed plant growth-promotion activity. Of all the endophytic fungi isolated, Penicillium sp. was the most abundantly distributed fungal strain in all plants used in this study.

• Journal of Periodontal and Implant Science
• /
• v.32 no.4
• /
• pp.865-873
• /
• 2002

The primary cause of tooth loss after 30 years of age is periodontal disease. Destruction of alveolar bone by periodontal disease is done by bone resorbing activity of osteoclasts. Understanding differentiation and activation mechanism of osteoclasts is essential for controling periodontal disease. The purpose of this study is to identify the possible effects of Vitamin D and cytokines affecting osteoclasts and its precursor cells. Four to six week-old mice were killed and humerus, radius, tibia and femur were removed aseptically and washed two times with Hank's solution containing penicillin-streptomycin and then soft tissue were removed. Bone marrow cells were collected by 22 gauge needle. Cells were cultured in Hank's solution containing 1 mg/ml type II collagenase, 0.05% trypsin, 41mM EDTA. Supernatant solution was removed 5 times after 15 minutes of digestion with above mentioned enzyme solution, and remained bone particles were maintained in alpha-MEM for 15 minutes and $4^{\circ}C$ temperature. Bone particles were agitated for 1 minute and supernatant solution containing osteoclast precursor cells were filtrated with cell stainer. These separated osteoclast precursor cells were dispensed with 100-mm culture dish by $1{\times}10^7$ cells unit and cultured in ${\alpha}$- MEM containing 20 ng/ml recombinant human M-CSF, 30 ng/ml recombinant human soluble osteoclast differentiation factor and 10% fetal calf serum for 2 and 7 days. Total RNA of osteoclast precursor cells were extracted using RNeasy kit. One ${\mu}g$ of total RNA was reverse transcribed in $42^{\circ}C$ for 30 minutes using SuperScriptII reverse transcriptase. Expression of transcribed receptors of each hormone and cytokine were traced with 1 ${\mu}l$ of cDNA solution by PCR amplification. Vitamin D receptor WAS found in cells cultured for 7 days. TNF-${\alpha}$ receptor was found in cells cultured for 2 days and amount of receptors were increased by 7 days. IL-1 type I receptor was not found in cells cultured 2 and 7 days. But, IL-1 receptor type II was found in cells cultured for 2 days. TGF-${\alpha},{\beta}$type I receptor was found in cells cultured 2 and 7 days, and amount of receptors were increased by 7 days of culture. These results implies Vitamin D and cytokines can affect osteoclasts directly, and affecting period in differentiation cycle of osteoclasts is different by Vitamin D and cytokines.

• Clinical and Experimental Reproductive Medicine
• /
• v.25 no.2
• /
• pp.199-205
• /
• 1998

The present study was performed to analyze the expression of LH genes in the rat ovary. Expression of LH subunit genes in the rat ovary was demonstrated by amplification of ovarian RNA by RT-PCR. The ovarian $LH_\beta$ transcripts contained at least two parts of the published cDNA structure, the pituitary exons 1, 2 and 3 and the part of testicular ex on 1 in the major trancripts form in rat testis. Using RIA, significant amount of LH-like molecules were detected in crude ovarian extracts, and the competition curves with increasing amount of tissue extracts were parallel with those of standard peptide, indicating that the ovarian immunoreactive LH-like material is similar to authentic pituitary LH molecule. The administration of PMSG to immature rats resulted in a sharp decrease of the ovarian LH contents after 24 h post-injection. In conclusion, these findings demonstrate that genes for LH subunits are expressed in the rat ovary, and suggest that LH can playa central role in regulation of female reproduction with both endocrine (by pituitary LH) and auto- and/or para-crine (by ovarian LH) manner.

• Journal of Microbiology and Biotechnology
• /
• v.16 no.9
• /
• pp.1377-1383
• /
• 2006

Among 46 Acinetobacter baumannii isolates collected in 2004, two imipenem-resistant isolates were obtained from clinical specimens taken from patients hospitalized in Busan, Republic of Korea. Two carbapenemase-producing isolates were further investigated to determine the mechanism of resistance. These isolates were analyzed by antibiotic susceptibility testing, microbiological tests of carbapenemase activity, determination of pI, transconjugation test, enterobacterial repetitive consensus (ERIC)-PCR, and DNA sequencing. Two cases of infection by A. baumannii producing the IMP-1 ${\beta}$-lactamase were detected. The isolates were characterized by a modified cloverleaf synergy test and EDTA-disk synergy test. Isoelectric focusing of crude bacterial extracts revealed nitrocefin-positive bands with a pI value of 9.0. PCR amplification and characterization of the amplicons by direct sequencing indicated that the isolates carried a $bla_{IMP-l}$ determinant. The isolates were characterized by a multidrug resistance phenotype, including penicillins, extended-spectrum cephalosporins, carbapenems, and aminoglycosides. These results indicate that the observed imipenem resistance of two Korean A. baumannii isolates was due to the spread of an IMP-1-producing clone. Our microbiological test of carbapenemase activity is simple to screen class B metallo-${\beta}$-lactamase-producing clinical isolates to determine their clinical impact and to prevent further spread. This study shows that the $bla_{IMP-l}$ resistance determinant, which is emerging in Korea, may become an emerging therapeutic problem, since clinicians are advised not to use extended-spectrum cephalosporins, imipenem, and aminoglycosides. This observation emphasizes the importance of having effective control measures in Asian hospitals, such as early detection of colonized patients, isolation procedures, and a judicious use of antibiotics.

• Advances in Traditional Medicine
• /
• v.4 no.2
• /
• pp.104-111
• /
• 2004

Sasang Constitutional Medicine is a major branch of Korean Traditional Oriental Medicine. The differences of disease susceptibility to be shown in Sasang constitution may be due to genetic factors. Therefore, we examined interrelationship among cerebral infarction (CI), apolipoprotein E (apoE) gene polymorphism, and Sasang constitutional classification. ApoE is a key protein modulating the highly atherogenic apoB containing lipoproteins and is a candidate gene for the development of coronary artery disease (CAD). The ${\varepsilon}2\;and/or\;{\varepsilon}4$ alleles were the first to be implicated in premature CAD, which resulted in this polymorphism being extensively studied. We investigated the association between apoE genotype and CI by case-control study in a Korean population. We also classified CI patients and control group into groups according to Sasang Constitutional Medicine. 196 CI patients and 379 controls without CI were examined. ApoE genotype was determined by 8% polyacrylamide gel separation after DNA amplification. A significant difference in the apoE genotype distribution was observed in the CI patients compared with that in controls ($X^{2}$=14.920, df=4, P=0.005). Also, the frequency of Taeumin constitution in patients with CI was significantly higher than that in controls (58.0% vs. 36.9%; P<0.001). However, the Taeumin constitution did not enhance the relative risk for CI in the subjects with apoE ${\varepsilon}2\;and/or\;{\varepsilon}4$ alleles. No differences in the apoE genotypes frequencies were observed in the Taeumin compared with that in the other constitutions. In addition, we investigated whether the DD genotype of angiotensin converting enzyme (ACE) gene, a candidate gene for CI, was associated with CI, Taeumin constitution, and apoE polymorphism. As a result, the frequency of Taeumin constitution was significantly higher in CI patients with both apoE ${\varepsilon}3/{\varepsilon}4$ and ACE ID/DD genotypes than in the remaining Sasang constitutions (14.5% vs. 8.3% and 0%) ($X^{2}$=13.521, df=6, P=0.035). In summary, we concluded that the apoE polymorphism is a major risk factor for CI in Koreans and the ACE ID/DD genotype enhanced the relative risk for CI in the subjects with apoE ${\varepsilon}3/{\varepsilon}4$ genotype and Taeumin constitution.

• Journal of Korean Society of Forest Science
• /
• v.102 no.2
• /
• pp.223-228
• /
• 2013

Phytoplasmas were detected consistently in 42 mulberry cultivars showing dwarf disease using DNA analysis by amplification with phytoplasma universal primer pairs P1/P7 (about 1.8 kb and R16F2n/R2 (about 1.2 kb). The point mutation from 42 cultivars of mulberry tree was detected by single-strand conformation polymorphism (SSCP) analysis. The SSCP profiles were clearly observed from all of cultivars in 8% polyacrylamide gel, electrophoresizing for and running 8-15 hrs. at 150V, $10^{\circ}C$. The MD and JWB phytoplasma PCR products was mixed and electrophoresis was performed to detect their polymorphism. In this results, the SSCP profiles of all bands of MD and JWB were analyzed on single lane and were distinct in their each of band patterns. The SSCP analysis was possible to detect of 1.8 kb and 1.2 kb nucleotide size and near close band patterns were distinct by mix of two samples. Previously, it was only possible to detect of point mutation under 600 bp nucleotide sequence by SSCP analysis but this modification of SSCP technique was possible to detect clearly SSCP band patterns of about 1.8 kb and 1.2 kb nucleotides.

• Korean Journal of Agricultural Science
• /
• v.28 no.2
• /
• pp.78-84
• /
• 2001

This study was analyzed by PCR technique with specific primer in order to investigate the characteristics of ${\beta}$-lactoglobulin (${\beta}$-LG) gene 5'flanking region in Korean native goat. This work confirmed amplified product of 1,077 bp fragments obtained from the amplification of ${\beta}$-LG promoter from genomic DNA using PCR in Korean native goat. The nucleotide sequence of ${\beta}$-LG gene 5'flanking region in Korean native goat as compared with that of sheep ${\beta}$-LG were different at 46 base of 897 nucleotides, and showed high homology as about 94.9% each breed. Especially we confirmed that the difference of nucleotide sequences between Korean native goat and sheep were consisted of $T{\rightarrow}C$ substitution and $C{\rightarrow}T$ substitution reversely. As a consequences, the sequences of ${\beta}$-LG gene 5'flanking region showed a high homology between Korean native goat and sheep. Furthermore we should be studied that relationships between the control of gene expression and nucleotide sequences of transcription factor in Korean native goat.

• Interdisciplinary Bio Central
• /
• v.4 no.3
• /
• pp.10.1-10.12
• /
• 2012

Introduction: We investigated frameshift suppressor tRNAs previously reported to use five-base anticodon-codon interactions in order to provide a collection of frameshift suppressor tRNAs to the synthetic biology community and to develop modular frameshift suppressor logic devices for use in synthetic biology applications. Results and Discussion: We adapted eleven previously described frameshift suppressor tRNAs to the BioBrick cloning format, and built three genetic logic circuits to detect frameshift suppression. The three circuits employed three different mechanisms: direct frameshift suppression of reporter gene mutations, frameshift suppression leading to positive feedback via quorum sensing, and enzymatic amplification of frameshift suppression signals. In the course of testing frameshift suppressor logic, we uncovered unexpected behavior in the frameshift suppressor tRNAs. The results led us to posit a four-base binding hypothesis for the frameshift suppressor tRNA interactions with mRNA as an alternative to the published five-base binding model. Conclusion and Prospects: The published five-base anticodon/codon rule explained only 17 of the 58 frameshift suppression experiments we conducted. Our deduced four-base binding rule successfully explained 56 out of our 58 frameshift suppression results. In the process of applying biological knowledge about frameshift suppressor tRNAs to the engineering application of frameshift suppressor logic, we discovered new biological knowledge. This knowledge leads to a redesign of the original engineering application and encourages new ones. Our study reinforces the concept that synthetic biology is often a winding path from science to engineering and back again; scientific investigations spark engineering applications, the implementation of which suggests new scientific investigations.