• Korean Journal of Microbiology
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• v.27 no.3
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• pp.176-180
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• 1989

There are three pseudourdine ($Psi$)bases in the E. coli $tRNA^{phe}$ In order to study the function of the pseudouridine bases in the $tRNA^{phe}$, changes of bases $tRNA^{phe}$ gene to other bases were undertaken by the site-specific mutagenesis. Site-specific mutagenesis of T in the pheW gene, a $tRNA^{phe}$ gene of E. coli, corresponding to the baseat the No.32 position to C and also T corresponding to the base at the No.39 position to C were performed using Kunkel's uracil-containing template method. Identification of mutants were undertaken by the KNA sequencing techniques of the mutated pheW genes and activities of the mutated pheW genes complementing to E. coli NP37 mutant($pheS^{-ts}$) using the recombinant plasmid containing the mutated genes. Neither NP37 harboring pheW gene mutated at No.32 position nor NP37 harboring pheW gene mutated at No.39 position can be grown at non-permissive temperature. The result means that both mutated pheW genes can not complement to E. coli NP37, and that the pseudouridine bases are essential to the activity of the E. coli $tRNA^{phe}$ in vivo.

• Korean Journal Plant Pathology
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• v.1 no.2
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• pp.101-108
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• 1985

Histopathological changes in the witches'-broom mycoplasma (MLO) infected jujube trees after trunk injection of oxytetracycline HCl (OTC) solution were investigated by using light microscope, fluorescence microscope and electron microscope. In contrast to the healthy leaves, adaxial and abaxial bundle sheath extensions in the major veins of diseased leaves were highly developed, but mesophyll cells were very small, loose and necrosed. In the diseased leaves, excessive phloem was formed, xylem differentiation was supressed and polyphenols were accumulated. Jujube trees treated with 500ml of 2000ppm solution of OTC showed complete remission of witches'-broom symptoms above the injection site, but cells in the sheath extention were hypertrophied and sieve tube necrosis occurred in the secondary phloem of major veins. MLO-specific fluorescence was not observed in the samples of diseased jujube trees treated with OTC, while those from non-treated infectedstress distinctly showed a moderate amount of MLO-specific fluorescence. In the observation under the electron microscope, sieve element of diseased tissues and its associated companion cells were found to have collapsed. Parenchymas cells contained many large starch filled plastids and most samples of diseased and OTC-treated tissues showed an abnormal accumulation of starch compared to the healthy controls. Mycoplasma-like organisms were observed only within mature sieve elements in diseased tissues, but never in OTC-treated tissues.

• Journal of Gastric Cancer
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• v.4 no.4
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• pp.225-229
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• 2004

Purpose: Some patients develop gastroesophageal reflux disease (GERD) after a gastrectomy for stomach cancer. Therefore, we conducted this research to gain an understanding of esophageal acidity and motility change. Materials and Methods: From July 2002 to March 2004, the cases of 15 randomized patients with stomach cancer who underwent a radical subtotal gastrectomy (RSG) with Billroth I(B-I) reconstruction (n=12) or a radical total gastrectomy (RTG) with Roux-en-Y (R-Y) gastroenterostomy (n=3) were analyzed. We investigated the clinical values of the ambulatory 24-hour pH monitoring and esophageal manometry in these patients, just before discharge from the hospital after an operation. Results: GERD was present in three patients ($20\%$). Compared with two reconstructive procedures, 3 of the 12 patients in the RSG with B-I group had GERD; however, none of RTG with R-Y group had GERD. Compared with pathologic stage, 2 of 9 patients in stage I, 1 of 2 patients in stage II, none of 3 patients in stage III, and none of 1 patient in stage IV had GERD. Esophageal manometry was performed in 10 patients. Nonspecific esophageal motility disorder (NEMD) was present in 7 patients. Conclusion: Some patients had GERD as a complication following a gastrectomy for stomach cancer. We suspect that the postoperative esophageal symptom is due to not only bile reflux but also gastroesophageal acid reflux. Therefore, careful observation is recommended for the detection of GERD.

• Investigative Magnetic Resonance Imaging
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• v.12 no.2
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• pp.148-152
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• 2008

Purpose : To find the MR findings and evaluate the usefulness of MR in flexor hallucis longus(FHL) dysfunction. Materials and Methods : From 1992 to 2003, fourty patients were found to have surgically confirmed FHL dysfunction. 24 cases of 22 patients who had performed MR were included in this study. We analyzed the signal intensity of FHL tendon and muscle, tendon sheath, sheath effusion, and bone lesions, retrospectively. Results : Non-specific, increased sheath effusion of FHL tendon was seen in 12 cases (50%). Large amount of sheath effusion(grade 3) was observed in 5 cases (21%). The signal intensity of FHL tendon was normal in all cases. High signal intensity at the FHL muscle, proximal to musculotendinous junction was seen in 1 case (4%). One case (4%) of marrow edema of the talus and another one case (4%) of osteochondritis dissecans of the talus was seen. Conclusion : Non-specific, increased sheath effusion of FHL tendon was observed on MR in FHL dysfunction patients. Therefore, MR has a limited role in diagnosis of FHL dysfunction and is useful to exclude other bone and tendon diseases causing medial ankle pain.

• Journal of fish pathology
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• v.27 no.1
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• pp.47-56
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• 2014

Propolis is a beehive product with a very complex chemical composition, widely used in folk medicine because of its several therapeutic activities. This study was conducted to measure the efficacy of propolis on non-specific defense reactions, specific immune response, and protection levels against pathogen challenge with Streptococcus iniae. in vitro and in vivo. In vitro, the phagocytic activity and NBT assay of peripheral blood leukocytes (PBL) were evaluated in a various propolis extractsconcentrations (0, 10, 50, 100, 150, 250 and $500{\mu}g/ml$). The optimal concentration showing activation of propolis extracts was determined to $100{\mu}g/ml$. In vivo, they were divided into four groups (PBS, propoli extractss, vaccine, propolis extracts + vaccine) in vivo. Fish were received i.p. injection of either PBS or propolis extracts, and in the presence or absence of formalin inactivated S. iniae ($1{\times}10^8$ CFU/fish), respectively. The level of haematocrit is not affected among experimental groups. The phagocytic activity and the NBT reduction activities of head kidney phagocyte were markedly (p<0.05)augmented in the propolis extracts groups than in the PBS-control group, respectively. The level of serum lysozyme activity was significantly (p<0.05) increased in the propolis extracts treated groups than in the PBS-control group. The agglutinin titer was significantly (p<0.05) enhanced in the vaccine+propolis extracts group than in the vaccine group, but there was no difference between PBS-control and propolis treated group. The results of the present study suggest that propolis extracts seems to be a promising compounds of non-specific immune stimulator, also being able to use a good adjuvant.

• The Journal of the Petrological Society of Korea
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• v.25 no.4
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• pp.349-360
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• 2016

The Bunam Stock ($29.5km^2$ area) is an outcrop of plutonic complex classified four facies: coarse-grained granite, quartz monzodiorite, granodiorite and fine-grained granite. Three facies except the last one exhibit very irregular boundaries with gradational compositional variations between both facies and show concentric zoning from the central quartz monzodiorite through granodiorite to outer coarse-grained granite. Mafic microgranular enclaves (MME) commonly occur in granodiorite. Some MMEs, have very fine-grained chilled margins and indentedly crenulate contacts, and display horizontally circular and vertically elongate shapes. Their shape and granularity indicate coeval flow and mingling of partly crystalline felsic and mafic magmas. MMEs exhibit dark fine-grained margins giving them a ellipsoidal form that has been attributed to undercooling of a mafic magma as blobs intruded into a felsic magma. The observed relations in the Bunam Stock identify that two endmembers are coarse-grained granite from a felsic magma and quartz monzodiorite from a mafic magma, and hybrid is granodiorite including MMEs. So they exhibit concentric zoning that lays the center on the mafic endmember due to magma mixing at the contacts of two magmas, when mafic magma injected into felsic magma. Thus the quartz monzodiorite may probably represent an ancient conduit of mafic magma transport through a granitic magma chamber. Mafic magma would rise through the conduit in which favorable conditions for magma mixing occurred. All these features suggest that they formed from mixing processes of calc-alkaline magma in the Bunam Stock.

• Economic and Environmental Geology
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• v.20 no.1
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• pp.19-34
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• 1987

The Nokdong As-Zn deposit, located 28 km south of Kyeongju City, Southern Korea, has been investigated by a deep drilling programme. The mineralized zone is roughly 290m long and 180m wide at surface and is hosted in a pipe diatreme infilled with poor to well bedded felsic volcaniclastics. The diatreme was formed by explosive volcanic activity, of probably early Tertiary age, subsequent hydrothermal alteration and mineralization took place concurrently within stratigraphic layers in diatreme. Coarse volcaniclastics in the center part of the diatreme, together with complex systems of fracturing, acted as pathways for late hydrothermal fluids which caused alteration of volcanic material to sericite, chlorite and carbonate and precipitated ore minerals, quartz and calcite in the voids. Porosity and permeability were key factors in determining which portions of the layered diatreme were mineralized. The lower part of certain layers retained a relatively high porosity and were extensively mineralized. Metallic mineralization, consisting mostly of pyirte, sphalerite and arsenopyrite, is found as disseminations, tuff-breccia filling and veins.

• Journal of the Mineralogical Society of Korea
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• v.22 no.2
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• pp.129-138
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• 2009

The XRF core scanner was used, to analyze high resolution chemical elements in deep sea sediment cores from Clarion-Clipperton fracture zone of the northeastern Pacific. Comparison of data estimated by the XRF core scanner with ICP-AES showed relatively weak correlation coefficients between elements (especially Ba, Pb, Sr, Zr) except for Mn contents ($r^2$ > 0.89). However down-core variations of most elements seemed to be well matched each other and furthermore, XRF core scanner data reflected changes of sedimentary facies characterized by sediment colors. Mn/Al ratio dramatically changed at boundaries of facies in BC08-02-05 and BC08-02-13 but progressive changes occured in BC08-02-02, BC08-02-09 and BC08-02-10 where the sediments have been affected by bioturbations. The difference of Mn/Al ratio in each facies (Facies I, Facies II, Facies III) has been caused by redox condition of depositional environment. Vertical change of Mn/Al ratio were divided into two types probably affected by activities of benthic organisms in the study area.

• Reproductive and Developmental Biology
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• v.32 no.1
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• pp.33-38
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• 2008

DNA methylation is involved in tissue-specific gene control and essential for normal embryo development Octamer-binding transcription factor 4 (Oct-4) is one of the most important transcription factors for early differentiation. This study was performed whether the bovine Oct-4 is tissue specific or developmental dependent epigenetic mark, we investigated transcripts and the methylation status of CpGs of 5'-promoter region of Oct-4 in bovine preimplantation embryos. Oct-4 transcripts were highly detected in morula and blastocyst, while they were present low levels in sperm and 2- to 8-cell stage embryos. These results suggest that de novo expression of Oct-4 initiates at morula stage of embryogenesis. Here we determined that there is a tissue-dependent differentially methylated region (T-DMR) in the 5'-promoter region of Oct-4. The methylation status of the Oct-4 T-DMR was distinctively different in the oocyte from that in the sperm and adult somatic tissues and changed from zygote to blastocyst stage, suggesting that active methylation and demethylation occur during preimplantation development. Based on these results, the 5'-promoter region of Oct-4 gene is target for DNA methylation and the methylation status changes variously during embryonic development in bovine.

• Applied Biological Chemistry
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• v.40 no.3
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• pp.189-195
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• 1997

The structural basis of Iysine specificity of Achromobacter protease I (API) was investigated by means of site-directed mutagenesis. The precursor protein in which Glu190, one of the two candidates for determining Iysine specificity, was substituted by glutamine, aspartic acid or leucine was processed autocatalytically to attaln full pretense activity with lysine specificity. The substitution of the other candidate, Asp225, for asparagine or leucine produced no mature active forms of pro-API. The precursor protein of the mutant D225E slowly matured autocatalytically. The lysylendopeptidase activity of the mature D225E was 0.25% of that of native API, and this reduced activity is mainly due to a decrease in the affinity of the enzyme for lysine. These results suggest that Asp225 plays a critical rol in restricted substrate specificity as a lysylendopeptidase. However, D225E exhibited no measurable activity for synthetic ornithine substrate. Since the hydroxyl group of Ser194 in this mutant retained essentially the same reactivity to DFP or PMSF as that in native API, it can be noted that a methylene unit longer side chain of residue 225 is not compensated by a methylene unit shorter side chain at subsite P1 in the bound substrate.