• Biomedical Science Letters
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• v.8 no.1
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• pp.29-37
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• 2002

Listeria monocytogenes poses an increasing health risk, which in part is due to increasing health risk, consumption of ready-to-eat food products and the introduction of increasing numbers of food products from regions with different dietary habits. L. monocytogenes can be present in meat, shellfish, vegetables, unpasteurised milk and soft cheese and poses a risk if food containing these products is stored at refrigeration temperature and is not properly heated before consumption, as L. monocytogenes is psychrophilic. Amplified-fragment length polymorphism (AFLP) analysis is the method of genotypic techinique in which adaptor oligonucleotides are ligated to restriction enzyme fragments and then used as target sites for primers in a PCR amplification. The amplified fragments are electrophoretically separated to give strain-specific band profiles. Single-enzyme approach that did not require costly equipment or reagents for the fingerprinting of strains of Listeria monocytogenes was developed. Single-enzyme amplified fragment length polymorphism (SE-AFLP) analysis was used to perform species and strain identification of Salmonella, Shigella, Yersinia and E. coli. By careful selection of AFLP primers, it was possible to obtain reproducible and sensitive identification to strain level. The AFLP patterns of L. monocytogenes are divided by the kinds of specimens in which were isolated. SE-AFLP fragments can be analyzed using standard gel electrophoresis, and can be easily scored by visual inspection, due to the low complexity of the fingerprint obtained by this method. These features make SE-AFLP suitable for use in either field or laboratory applications.

• International Journal of Industrial Entomology and Biomaterials
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• v.10 no.2
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• pp.79-86
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• 2005

Molecular markers have increasingly been used in plant genetic analysis, due to their obvious advantages over conventional phenotypic markers, as they are highly polymorphic, more in number, stable across different developmental stages, neutral to selection and least influenced by environmental factors. Among the PCR based marker techniques, ISSR is one of the simplest and widely used techniques, which involves amplification of DNA segment present at an amplifiable distance in between two identical microsatellite repeat regions oriented in opposite direction. Though ISSR markers are dominant like RAPD, they are more stable and reproducible. Because of these properties ISSR markers have recently been found using extensively for finger printing, pohylogenetic analysis, population structure analysis, varietal/line identification, genetic mapping, marker-assisted selection, etc. In mulberry (Morus spp.), ISSR markers were used for analyzing phylogenetic relationship among cultivated varieties, between tropical and temperate mulberry, for solving the vexed problem of identifying taxonomic positions of genotypes, for identifying markers associated with leaf yield attributing characters. As ISSR markers are one of the cheapest and easiest marker systems with high efficiency in generating polymorphism among closely related varieties, they would play a major role in mulberry genome analysis in the future.

• Biotechnology and Bioprocess Engineering:BBE
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• v.5 no.3
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• pp.169-173
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• 2000

On human chromoscomes, a short sequence of DNA is known to repeat a number of times. These are called variable number of tandem repeat (VNTR) or short tandem respeat (STR) which has a short core. VNTR and STR are used in the filed of forensic science, evolution, and anthropology. In this work, we examined allele frequencies of one VNTR (YNZ22) and three STRs (NeuR, D21S11, Humth01) in a korean population sample by polymerase chain reaction (RCP) followed by high-resolution polyacrylamide gel electro-phoresis (PAGE) with silver stain. Subsequently, the polymorphism information content (PIC) was calculated : the hifhest PIC was observed in the NeuR locus (0.95680) and lowest in the Humth01 locus (0.75809).

• Proceedings of the Korean Society of Fisheries Technology Conference
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• 2000.05a
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• pp.487-488
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• 2000

Genomic DNA was isolated from the marine microalgae representing genetic characteristics and genomic polymorphisms by polymerase chain reaction amplification of DNA as arbitrary primers. The electrophoretc analysis of PCR-RAPD products showed hig levels of variation between different genus and little variation between different species. Outer of these primers, 6 generated 248 highly reproducible RAPD markers, producing almost seven polymorphic bands per primers. The degree of similarity frequency between Chaetoceros gracilis and Chaetoceros calcitrans species showed 90％ as calculated by sharing analysis. The RAPD polymorphism generated by this primer may be used as a genetic marker for genus or species identification in important marine microalgae. (omitted)

• Toxicological Research
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• v.20 no.3
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• pp.187-193
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• 2004

This study aimed to determine the association of maternal oxidative stress and adverse pregnancy outcome with serum vitamin C concentration and a myeloperoxidase (MPO) genetic polymorphism during pregnancy. We investigated 450 pregnant women who visited Ewha Womans University Hospital for prenatal care during gestational weeks 24～28. During the second trimester, we measured serum vitamin C levels and urinary 8-hydroxyde-2'-deoxyguanosine (8-OHdG) and malondialdehyde (MDA) as an oxidative stress biomarker. We determined the presence of a maternal MPO polymorphism (G-to-A substitution at nucleotide 463) using a PCR-RFLP assay. We compared the level of oxidative stress and birth weight with the vitamin C concentration and the presence of the MPO polymorphism. The mean level of maternal oxidative stress tended to be higher and the birth weight lower for MPO type A/A than for types A/G and G/G. Vitamin C levels above the 75 percentiles were associated with reduced concentrations of urinary MDA and 8-OHdG but increased birth weight. Our data demonstrate that oxidative stress and neonatal birth weight are associated with the MPO genetic polymorphism, with the association modified by the maternal vita-min C levels.

• Korean Journal of Biological Psychiatry
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• v.13 no.4
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• pp.267-272
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• 2006

Objectives : Schizophrenia is a clinically heterogenous disease with a strong genetic component. Many studies have suggested that brain-derived neurotrophic factor(BDNF) is involved in the pathophysiology of schizophrenia. This study was performed to determine whether there is an association between BDNF Val66Met polymorphism and schizophrenia. Methods : To identify any genetic predisposition to schizophrenia, we investigated the BDNF Val66Met polymorphism in 106 patients with schizophrenia and 147 normal controls with PCR-RFLP method. Statistical analyses were used to test the association between and BDNF Val66Met genotype and Schizophrenia. Results : No association was found between BDNF Val66Met polymorphism and schizophrenia. No significant differences were found comparing the BDNF genotype distributions according to the age of onset, the number of admission and familial loading in schizophrenia. Conclusion : This result indicates that BDNF Val66Met polymorphism is not associated with schizophrenia. However, further studies with a large number of subjects are needed to confirm whether the BDNF gene is related to schizophrenia.

• Korean Journal of Head & Neck Oncology
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• v.12 no.2
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• pp.169-176
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• 1996

Tuberculous cervical lymphadenitis is still an important cause of neck mass in Korea. Tuberculosis is an important differential diagnosis in patients of cervical lymphadenopathy. Rapid and sensitive test for the diagnosis of tuberculosis is essential for the approapiate treatment. Up to now, conventional diagnostic methods for M. tuberculosis were acid-fast bacilli(AFB) stain and culture of M. tuberculosis. The direct microscopic examination of AFB by Ziehl-Neelsen stain is rapid, but often negative. The culture for M. tuberculosis is time-consuming, taking 4 to 8 weeks. Recently various methods to detect Mycobacterial DNA, including PCR and restriction fragment length polymorphism(RFLP) analysis have been reported. Here we represent a simple method for the confirmation of M. tuberculosis and exclusion of the other Mycobacterial species by RFLP analysis and silver staining of polyacrylamide gel electrophoresis after nested PCR for a repetitive DNA sequence(IS986) specific for M. tuberculosis from fresh or paraffin-embedded biopsy specimens. This result leads us to conclude that this method is simple, rapid and possibly applicable to confirm M. tuberculosis and rule out the other Mycobacteria species from the clinical specimens in the clinical laboratories.

• Parasites, Hosts and Diseases
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• v.34 no.4
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• pp.259-266
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• 1996

The taxonomic validity of morphological group III Accnthamoeba app. is uncertain. In the present study. six type strains of group III Aconthamoeba spry. , A. culbertsoni, A. heniyi, A. pustulosc, A. palestinensis, A. royrebn and A. lenticulnto were subjected for the evaluation or their taxonomic validity by comparison of the isoeneyme patterns by isoelectic focusing on polyacrylamide gels, mitochondrial DNA (Mt DNA) restriction fragment length polymorphism (RFLP) . and small subunit ribosomal DNA (ssu rDNA) PCR-RFLP patterns. The Mt DNA RFLP patterns were heterogeneous between the species. The type strains of A. pclestinensls and A. pustulosc showed almost identical patterns of isoenrymes and rDNA PCR-RFLP with an estimated sequence divergence of 2.6%. The other species showed heterogeneous patterns of isoenxymes and rDNA PCR- RFLP. It is likely that A. pustuLosc is closely related with A. palestinensis and that the former may be regarded as a junior synonym of the latter.

• The Journal of Korean Society of Virology
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• v.27 no.2
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• pp.169-176
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• 1997

In this study, the feasibility of identification and genotypic differentiation of enteroviruses was investigated by using nested reverse transcription-polymerase chain reaction (nested RT-PCR), single-stranded conformation polymorphism (SSCP), and restriction fragment length polymorphism (RFLP) techniques. Two hundred seventy-four clinical samples were assayed by both nested RT-PCR and tube culture method using MRC-5 and MK cells; 58 (86.6%) out of 67 enterovirus culture-positive samples contained enteroviral RNA. In addition, 114 (55.1%) of 207 samples from patients with suspected enteroviral CNS disease with negative viral cultures were positive by the nested RT-PCR. The nested RT-PCR products were genotyped by the SSCP method and the results were compared with serotypes. We could differentiate 6 subtypes, 3 of which are similar to coxsackievirus B3, B5, echovirus 11, plus 3 other subtypes. RFLP cleaved with Sty I, Bgl I, and Xmn I yielded characteristic patterns for each laboratory strains. This study demonstrates the usefulness of the RT-PCR for the rapid diagnosis of enterovirus infection and the potentials of the SSCP method for differentiation of enterovirus strains.

• Journal of Ginseng Research
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• v.34 no.1
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• pp.41-46
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• 2010

Expensive herbs such as ginseng are always a possible target for fraudulent labeling. New mountain ginseng strains have occasionally been found deep within mountain areas and commercially traded at exorbitant prices. However, until now, no scientific basis has existed to distinguish such ginseng from commonly cultivated ginseng species other than by virtue of being found within deep mountain areas. Polymerase chain reaction (PCR) analysis of the internal transcribed spacer has been shown to be an appropriate method for the identification of the most popular species (Panax ginseng) in the Panax ginseng genus. A single nucleotide polymorphism (SNP) has been identified between three newly found mountain ginseng (KGD4, KGD5, and KW1) and already established Panax species. Specific PCR primers were designed from this SNP site within the sequence data and used to detect the mountain ginseng strains via multiplex PCR. The established multiplex-PCR method for the simultaneous detection of newly found mountain ginseng strains, Korean ginseng, and foreign ginseng in a single reaction was determined to be effective. This study is the first report of scientific discrimination of "mountain ginsengs" and describes an effective method of identification for fraud prevention and for uncovering the possible presence of other, cheaper ginseng species on the market.