• The Korean Journal of Physiology and Pharmacology
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• 제5권3호
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• pp.279-285
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• 2001

Although only a minority of the infected individuals develops atrophic gastritis and the malignancy, factors governing clinical outcomes subsequent to Helicobacter pylori (H. pylori) infection have not yet been defined. H. pylori infection is characterized by extensive infiltration of neutrophils. Myeloperoxidase (MPO) in neutrophils amplifies the oxidative potential of hydrogen peroxides that induce gastric mucosal damage, thus MPO is suspected to play a role in H. pylori-induced gastric injury. Therefore, we explored the association of host MPO genetic polymorphism with atrophic gastritis upon H. pylori infection. Biopsy specimens taken from the gastric mucosa were examined histologically in 87 patients. The PCR-RFLP assay was used to characterize MPO genotypes. The distributions of MPO genotypes were MPO (G/G) 82% and MPO (G/A) 18%. None of MPO (A/A) genotype was observed. A strong positive correlation between the levels of neutrophil infiltration and gastric atrophy found only in MPO (G/G) but not in MPO (G/A) genotype. These results suggest that MPO genotype is a critical determinant in the pathogenesis of atrophic gastritis subsequent to H. pylori infection. Further works need to clarify the functional relevance of MPO genetic polymorphisms on gastric cell injury.

• 한국식물병리학회지
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• 제14권2호
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• pp.177-183
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• 1998

A DNA fragment which is involved in tolassin production was cloned to obtain a molecular marker of Pseudomonas tolaasii, a casual agent of bacterial brown blotch disease of oyster mushroom (Pleurotus ostreatus). Tolaasin is a lipodepsipeptide toxin and known as a primary disease determinant of the P. tolaasii. It is responsible for formation of white line in agar when P. tolaasii were cultured against white line reacting organisms (WLROs). White line negative mutants (WL-) were generated by conjugation between rifampicin resistant strain of P. tolaasii and E. coli carrying suicidal plasmid pSUP2021 : : Tn5. The ability of tolaasin production of the WL- mutants was examined by hemolysis test, pathogenicity test, and high pressure liquid chromatography (HPLC) analysis of culture filtrate. All of the WL- mutants were lost the ability of tolaasin production (Tol-). Genomic library of the Tol- mutant was constructed in pLAFR3 and the cosmid clone containing Tn5 was selected. DNA fragment fro franking region of Tn5 was cloned from the plasmid and used as a probe in Southern blot. DNA-DNA hybridization with the probe to total DNA from group of bacteria ecologically similar to P. tolaasii including WLORs, fluorescent Pseudomonads isolated from oyster mushroom, P. agarici, P. gingeri, and some of other species of Psedomonas showed that some of the tested bacteria do not have any hybridized band and others have bands sowing RFLP. The cloned DNA fragment or its nucleotide sequence will be useful in detection and identification of the P. tolaasii.

• Parasites, Hosts and Diseases
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• 제41권4호
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• pp.181-188
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• 2003

A new species of Acanthamoeba was isolated from a freshwater fish in Korea and tentatively named Acanthamoeba sp. YM-4 (Korean isolate YM-4). The trophozoites were $11.0-23.0{\;}{\mu\textrm{m}}$ in length and had hyaline filamentous projections. Cysts were similar to those of A. culbertsoni and A. royreba, which were previously designated as Acanthamoeba group III. Acanthamoeba YM-4 can survive at $40^{\circ}C$, and its generation time was 19.6 hr, which was longer than that of A. culbertsoni. In terms of the in vitro cytotoxicity of lysates, Acanthamoeba YM-4 was weaker than A. culbertsoni, but stronger than A. polyphaga. On the basis of the mortality of experimentally infected mice, Acanthamoeba YM-4 was found to be highly virulent. The isoenzymes profile of Acanthamoeba YM-4 was similar to that of A. royreba. An anti-Acanthamoeba YM-4 monoclonal antibody, McAY7, was found to react only with Acanthamoeba YM-4, and not with A. culbertsoni. Random amplified polymorphic DNA marker analysis and RFLP analysis of mitochondrial DNA and of 18S small subunit ribosomal RNA, placed Acanthamoeba YM-4 in a separate cluster on the basis of phylogenetic distances. Thus the Acanthamoeba Korean isolate YM-4 was identified as a new species, and assigned as Acanthamoeba sohi.

• Parasites, Hosts and Diseases
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• 제44권2호
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• pp.117-125
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• 2006

Genetic diversity of 18 Acanthamoeba isolates from ocean sediments was evaluated by comparing mitochondrial (mt) DNA RFLP, 18S rDNA sequences and by examining their cytopathic effects on human corneal epithelial cells versus reference strains. All isolates belonged to morphologic group II. Total of 16 restriction phenotypes of mtDNA from 18 isolates demonstrated the genetic diversity of Acanthamoeba in ocean sediments. Phylogenetic analysis using 18s rDNA sequences revealed that the 18 isolates were distinct from morphological groups I and III. Fifteen isolates showed close relatedness with 17 clinical isolates and A. castellanii Castellani and formed a lineage equivalent to T4 genotype of Byers' group. Two reference strains from ocean sediment, A. hatchetti BH-2 and A. griffini S-7 clustered unequivocally with these 15 isolates. Diversity among isolates was also evident from their cytopathic effects on human corneal cells. This is the first time describing Acanthamoeba diversity in ocean sediments in Korea.

• Parasites, Hosts and Diseases
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• 제51권1호
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• pp.1-8
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• 2013

Taenia solium, T. saginata, and T. asiatica are taeniid tapeworms that cause taeniasis in humans and cysticercosis in intermediate host animals. Taeniases remain an important public health concerns in the world. Molecular diagnostic methods using PCR assays have been developed for rapid and accurate detection of human infecting taeniid tapeworms, including the use of sequence-specific DNA probes, PCR-RFLP, and multiplex PCR. More recently, DNA diagnosis using PCR based on histopathological specimens such as 10% formalin-fixed paraffin-embedded and stained sections mounted on slides has been applied to cestode infections. The mitochondrial gene sequence is believed to be a very useful molecular marker for not only studying evolutionary relationships among distantly related taxa, but also for investigating the phylo-biogeography of closely related species. The complete sequence of the human Taenia tapeworms mitochondrial genomes were determined, and its organization and structure were compared to other human-tropic Taenia tapeworms for which complete mitochondrial sequence data were available. The multiplex PCR assay with the Ta4978F, Ts5058F, Tso7421F, and Rev7915 primers will be useful for differential diagnosis, molecular characterization, and epidemiological surveys of human Taenia tapeworms.

• Asian Pacific Journal of Cancer Prevention
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• 제17권6호
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• pp.2861-2866
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• 2016

It is thought that population characteristics of breast cancer may be due to a variation in the frequency of different alleles of genes such as CYP1B1. We aimed to determine the association of CYP1B1 polymorphisms in 200 breast cancer cases and 40 controls by PCR-RFLP. Frequencies were assessed with clinical and risk factors in Egyptian patients. The genotype LV and the Leu allele frequencies for patients and controls were 42.9% and 50%, and 52.9% and 53.3%, respectively), with no significant differences observed (P values = 0.8 and 0.6, respectively). There was also no significant association between genotypes and any risk factors for cases (P>0.05) except laterality and metastasis of the tumor (P values=0.006 and 0.06, respectively). The CYP1B1 polymorphism Val432Leu was not associated with breast cancer in Egypt, but may provide clues for future studies into early detection of the disease.

• Membrane and Water Treatment
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• 제10권6호
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• pp.395-404
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• 2019

The influence of chlorine on marine bacterial communities was examined in this study. A non-chlorine-adapted marine bacterial community (NCAM) and a chlorine-adapted bacterial community (CAM, bacterial community treated with $0.2mg-Cl_2/L$ chlorine) were cultivated for 1 month. A distinct difference was observed between the NCAM and CAM, which shared only eight operational taxonomic units (OTUs), corresponding to 13.1% of the total number of identified OTUs. This result suggested that chlorine was responsible for the changes in the marine bacterial communities. Kordiimonas aquimaris was found to be a chlorine-resistant marine bacterium. The effect of intermittent chlorination on the two marine biofilm communities formed on the reverse osmosis (RO) membrane surface was investigated using various chlorine concentrations (0, 0.2, 0.4, 0.6 and 0.8 mg $Cl_2/L$). Although the average number of adherent marine bacteria on the RO membrane over a period of 7 weeks decreased with increasing chlorine concentration, disinfection efficiencies showed substantial fluctuations throughout the experiment. This is due to chlorine depletion that occurs during intermittent chlorination. These results suggest that intermittent chlorination is not an effective disinfection strategy to control biofilm formation.

• Clinical and Experimental Reproductive Medicine
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• 제32권2호
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• pp.171-176
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• 2005

Objective: To investigate whether polymorphism of CYP19 gene is associated with the risk of advanced endometriosis in Korean women. Methods: Blood samples were collected from 202 endometriosis patients and 221 controls. The patients with endometriosis of stages III and IV diagnosed by both pathologic and laparoscopic findings to according modified AFS classification. The women undergoing laparoscopic surgery or laparotomy for non-malignant lesions were included in the control group. Polymerase chain reaction (PCR) and restriction fragment length polymorphism (RFLP) of PCR products were done to determine all individuals' genotype. Results: The heterozygous allele in CYP19 gene was the most common genotypes in both endometriosis and healthy control groups (52.0% vs. 46.1%). CYP19 gene polymorphisms did not show the significant differences between the control group and endometriosis group. Conclusion: The results suggested that the CYP19 genetic polymorphism was not associated with a risk of advanced endometriosis in Korean women.

• The Plant Pathology Journal
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• 제35권1호
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• pp.51-62
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• 2019

A great variable response was observed when PP-3 and PP-J encumbered with 116 populations of root knot nematode (RKN) at two different temperatures ($25{\pm}2^{\circ}C$ and $30{\pm}2^{\circ}C$) and concentrations ($10^4$ and $10^5$ spores/ml). The PCR reaction amplified intergenic region between cytochrome oxidase subunit II gene (COII) and large subunit of rRNA gene (lrRNA) of the mitochondrial genome of different RKN species. The primer C2F3 and 1108 identified M. incognita with the highest frequency (52.6%) followed by M. javanica (36.8%) and M. arenaria (10.5%). The sizes of PCR products were 1.7 kb for M. incognita and M. javanica populations while populations of M. arenaria produced 1.1 kb fragment. The digestion with Hinf I yielded three different fragment length patterns on 1.5 % agarose gel. From current research it is concluded that intra-Meloidogyne genetic variability exist in RKN populations which have better encumbrance with P. penetrans.

• The Plant Pathology Journal
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• 제38권2호
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• pp.78-89
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• 2022

Phaeosphaeria species are pathogenic on wheat, barley and a wide range of wild grasses. To analyze mating type loci of the Phaeosphaeria species and investigate mating type distribution in Iran, we sequenced mating type loci of 273 Phaeosphaeria isolates including 67 isolates obtained from symptomatic leaves and ears of wheat, barley, and wild grasses from two wheat growing region in Iran as well as 206 isolates from our collection from other regions in Iran which were isolated in our previous studies. Mating type genes phylogeny was successfully used to determine the species identity and relationships among isolates within the Phaeosphaeria spp. complex. In this study, we reported seven new host records for Phaeosphaeria species and the Phaeosphaeria avenaria f. sp. tritici 3 group was first reported from Iran in this study. Mating type distribution among Phaeosphaeria species was determined. Both mating types were present in all sampling regions from Iran. We observed skewed distribution of mating types in one region (Kohgiluyeh va Boyer-Ahmad) and equal distribution in the other region (Bushehr). However, when considering our entire dataset of 273 Iranian Phaeosphaeria isolates, the ratio of mating types was not deviated significantly from 1:1 suggesting possibilities for isolates of opposite mating type to interact and reproduce sexually, although the sexual cycle may infrequently occur in some regions especially when the climatic conditions are unfavorable for teleomorph development.