• Asian Pacific Journal of Cancer Prevention
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• v.15 no.3
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• pp.1375-1379
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• 2014

Background: Differences in clinicopathological characteristics of gastric cancer (GC) between young and older patients are controversial and a matter of debate. Determining the statistical significance of clinicopathological information with respect to age might provide clues for better management and treatment ofGC. Materials and Methods: A total ofl03 Indiao GC patients were enrolled for study and specimens were classified according to the AjCC-TNM system. Patients were grouped into two age-wise categories, young patients (<40 years; n=13) and older patients (${\geq}40$ years, n=90). The clinicopathological features of both groups were retrospectively examined and compared. p53 alterations were analyzed by polymerase chain reaction-single strand conformational polymorphism and immunohistochemistry methods at gene and protein levels respectively. The cases were considered p53 over-expressed if it was present in more than 25% of the tumor cells and p53 alterations was correlated with the clinicopathological characteristics of the patients as well as etiological factors for GC in both groups. Results: We found significant association of young patients with cancer stage (p=0.01), and very strong association with histology grade (p=0.064) and poorly differentiated (p=0.051) state of GC. However, neither young nor elderly patients showed associations with location, gender, etiological factors and p53 expression and alteration. Overall the male-to-female ratio of GC patients was 3.12 and the value was higher in the young (5.5) than in the older group (2.91). Conclusions: Clinicopathological features of GC like caocer stage, cell differentiation and histological grades were significantly different among young and old age cohorts. We observed a male predominance among the young group that decreased significantly with advancing age. More awareness of GC onset is required to detect cancer at an early stage for successful treatment.

• Journal of Microbiology and Biotechnology
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• v.18 no.2
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• pp.234-241
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• 2008

Agrobacterum tumefaciens-mediated transformation (ATMT) is becoming an effective system as an insertional mutagenesis tool in filamentous fungi. We developed and optimized ATMT for two Colletotrichum species, C. falcatum and C. acutatum, which are the causal agents of sugarcane red rot and pepper anthracnose, respectively. A. tumefaciens strain SK1044, carrying a hygromycin phosphotransferase gene (hph) and a green fluorescent protein (GFP) gene, was used to transform the conidia of these two Colletotrichum species. Transformation efficiency was correlated with co-cultivation time and bacterial cell concentration and was higher in C. falcatum than in C. acutatum. Southern blot analysis indicated that about 65% of the transformants had a single copy of the T-DNA in both C. falcatum and C. acutatum and that T-DNA integrated randomly in both fungal genomes. T-DNA insertions were identified in transformants through thermal asymmetrical interlaced PCR (TAIL-PCR) followed by sequencing. Our results suggested that ATMT can be used as a molecular tool to identify and characterize pathogenicity-related genes in these two economically important Colletotrichum species.

• Asian-Australasian Journal of Animal Sciences
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• v.19 no.7
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• pp.931-937
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• 2006

The full-length cDNA of the porcine SMPX gene was obtained by the rapid amplification of cDNA ends (RACE). The nucleotide sequences and the predicted protein sequences share high sequence identity with both human and mouse. The promoter of SMPX was sequenced and then analyzed to find the promoter binding sites. The reverse transcriptase-polymerase chain reaction (RT-PCR) revealed that SMPX has a high level of expression in heart and skeletal muscle, a very low expression in lung and spleen and no expression in liver, kidney, fat and brain. Moreover, SMPX has a differential expression level in skeletal muscle, the expression in 65-day embryos being higher than other stages. The porcine SMPX was mapped to SSCXp24 by using a somatic cell hybrid panel (SCHP) and was found closely linked to SW1903 using the radiation hybrid panel IMpRH. An A/G single nucleotide polymorphism (PCR-RFLP) in the 3'-untranslated region (3'-UTR) was detected in eight breeds. The analysis of allele frequency distribution showed that introduced pig breeds (Duroc and Large White) have a higher frequency of allele A while in the Chinese indigenous pig breeds (Qingping pig, Lantang pig, YushanBlack pig, Large Black-White pig, Small Meishan) have a higher frequencies of allele G. The association analysis using an experimental population (188 pigs), which included two cross-bred groups and three pure-blood groups, suggested that the SNP genotype was associated with intramuscular fat content.

• Asian Pacific Journal of Cancer Prevention
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• v.14 no.5
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• pp.2689-2698
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• 2013

Epithelial-to-mesenchymal transition (EMT) is a collection of events that allows the conversion of adherent epithelial cells, tightly bound to each other within an organized tissue, into independent fibroblastic cells possessing migratory properties and the ability to invade the extracellular matrix. EMT contributes to the complex architecture of the embryo by permitting the progression of embryogenesis from a simple single-cell layer epithelium to a complex three-dimensional organism composed of both epithelial and mesenchymal cells. However, in most tissues EMT is a developmentally restricted process and fully differentiated epithelia typically maintain their epithelial phenotype. Recently, elements of EMT, specially the loss of epithelial markers and the gain of mesenchymal markers, have been observed in pathological states, including epithelial cancers. Increasing evidence has confirmed its presence in human colon during colorectal carcinogenesis. In general, chronic inflammation is considered to be one of the causes of many human cancers including colorectal cancer(CRC). Accordingly, epidemiologic and clinical studies indicate that patients affected by ulcerative colitis and Crohn's disease, the two major forms of inflammatory bowel disease, have an increased risk of developing CRC. A large body of evidence supports roles for the SMAD/STAT3 signaling pathway, the NF-kB pathway, the Ras-mitogenactivated protein kinase/Snail/Slug and microRNAs in the development of colorectal cancers via epithelial-tomesenchymal transition. Thus, EMT appears to be closely involved in the pathogenesis of colorectal cancer, and analysis refered to it can yield novel targets for therapy.

• Clinical and Experimental Pediatrics
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• v.60 no.7
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• pp.221-226
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• 2017

Purpose: Escherichia coli sequence type (ST) 131, a multidrug-resistant clone causing extraintestinal infections, has rapidly become prevalent worldwide. However, the epidemiological and clinical features of pediatric infections are poorly understood. We aimed to explore the characteristics of ST131 Escherichia coli isolated from Korean children with urinary tract infections. Methods: We examined 114 uropathogenic E. coli (UPEC) isolates from children hospitalized at Chung-Ang University Hospital between 2011 and 2014. Bacterial strains were classified into STs by partial sequencing of seven housekeeping genes (adk, fumC, gyrB, icd, mdh, purA, and recA). Clinical characteristics and antimicrobial susceptibility were compared between ST131 and non-ST131 UPEC isolates. Results: Sixteen UPEC isolates (14.0%) were extended-spectrum ${\beta}-lactamase$ (ESBL)-producers; 50.0% of ESBL-producers were ST131 isolates. Of all the isolates tested, 13.2% (15 of 114) were classified as ST131. There were no statistically significant associations between ST131 and age, sex, or clinical characteristics, including fever, white blood cell counts in urine and serum, C-reactive protein, radiologic abnormalities, and clinical outcome. However, ST131 isolates showed significantly lower rates of susceptibility to cefazolin (26.7%), cefotaxime (40.0%), cefepime (40.0%), and ciprofloxacin (53.3%) than non-ST131 isolates (65.7%, 91.9%, 92.9%, and 87.9%, respectively; P<0.001 for all). ESBL was more frequently produced in ST131 (53.3%) than in non-ST131 (8.1%) isolates (P<0.01). Conclusion: ST131 E. coli isolates were prevalent uropathogens in children at a single medical center in Korea between 2011 and 2014. Although ST131 isolates showed higher rates of antimicrobial resistance, clinical presentation and outcomes of patients were similar to those of patients infected with non-ST131 isolates.

• Journal of the Korean Magnetic Resonance Society
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• v.4 no.2
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• pp.74-81
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• 2000

Saccharomyces cerevisiae Dna2 protein has biochemical activities: DNA-dependent ATPase, DNA helicase and DNA nuclease and is essential for cell viability. Especially, Pro$\^$504/ is determined as an important residue in ATPase, helicase, and nuclease activity. We synthesized and determined the three-dimensional solution structure of N-terminal domain comprising residues of Val$\^$501/ -_Phe$\^$508/ (Dna2$\^$pep/) using two-dimensional $^1$H-NMR and dynamical simulated annealing calculations. On the basis of a total of 44 experimental restraints including NOEs, $^3$J$\_$$\alpha$$\beta$/ and $^3$J$\_$$\alpha$$\beta$/ coupling constants, the solution structures of Dna2$\^$epe/ were calculated with the program CNS. The 23 lowest energy structures were selected out of 50 final simulated-annealing structures. The atomic RMSDs of the final 23 structures fur the individual residues were calculated with respect to the average structure. The mean RMSDs for the 23 structures were 0.042 nm for backbone atoms and 0.316 nm for all heavy atoms, respectively. The Ramachandran plot indicates that the $\Phi$, Ψ angles of the 23 final structures are properly distributed in energetically acceptable regions. Solution structure of Dna2$\^$pep/ showed a single unique turn spanning residues of Asn$\^$503/ Val$\^$506/.

• Pediatric Gastroenterology, Hepatology & Nutrition
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• v.17 no.3
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• pp.140-146
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• 2014

Purpose: The etiology of acute gastroenteritis (AGE) has changed since the introduction of the rotavirus vaccination. The aim of this study was to clarify which common pathogens, both bacterial and viral, are currently causing AGE in infants. Methods: Infants with acute diarrhea were enrolled. We tested for 10 bacterial pathogens and five viral pathogens in stool specimens collected from infants with AGE. The clinical symptoms such as vomiting, mucoid or bloody diarrhea, dehydration, irritability, and poor oral intake were recorded, and laboratory data such as white blood cell count and C-reactive protein were collected. The clinical and laboratory data for the cases with bacterial pathogens and the cases with viral pathogens were compared. Results: Of 41 total infants, 21 (51.2%) were positive for at least one pathogen. Seventeen cases (41.5%) were positive for bacterial pathogens and seven cases (17.1%) were positive for viral pathogens. Staphylococcus aureus (13 cases, 31.7%) and Clostridium perfringens (four cases, 9.8%) were common bacterial pathogens. Norovirus (five cases, 12.2%) was the most common viral pathogen. Fever and respiratory symptoms were common in the isolated viral infection group (p=0.023 and 0.044, respectively), whereas other clinical and laboratory data were indistinguishable between the groups. Conclusion: In our study, S. aureus (41.5%) and norovirus (12.2%) were the most common bacterial and viral pathogens, respectively, among infants with AGE.

• Journal of Microbiology and Biotechnology
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• v.22 no.3
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• pp.316-325
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• 2012

Xylanase has been used extensively in the industrial and agricultural fields. However, the low-yield production of xylanase from native species cannot meet the increasing demand of the market. Therefore, improving the heterologous expression of xylanase through basic gene optimization may help to overcome the shortage. In this study, we synthesized a high-GC-content native sequence of the thermostable xylanase gene xynB from Streptomyces olivaceoviridis A1 and, also designed a slightly AT-biased sequence with codons completely optimized to be favorable to Pichia pastoris. The comparison of the sequences' expression efficiencies in P. pastoris X33 was determined through the detection of single-copy-number integrants, which were quantified using qPCR. Surprisingly, the high GC content did not appear to be detrimental to the heterologous expression of xynB in yeast, whereas the optimized sequence, with its extremely skewed codon usage, exhibited more abundant accumulation of synthesized recombinant proteins in the yeast cell, but an approximately 30% reduction of the secretion level, deduced from the enzymatic activity assay. In this study, we developed a more accurate method for comparing the expression levels of individual yeast transformants. Moreover, our results provide a practical example for further investigation of what constitutes a rational design strategy for a heterologously expressed and secreted protein.

• The Journal of Natural Sciences
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• v.14 no.1
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• pp.51-61
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• 2004

T7 RNA polymerase is a single subunit RNA polymerase able to accomplish whole transcription process without auxiliary factors. T7 phage lysozyme involcing in destruction of host cell wall repress T7 transcription and affects transcription termination process. Therefore expression vector pT7lys containing T7 phage lysozyme gene was constructed and expressed. T7 phage lysozyme protein was purified to homogeneity by Ni-NTA column chromatography. Also amidase activity of the purified lysozyme was identified. In order to understand the effect of the lysozyme on the sequence specific transcription termination. T7 transcription elongation complexes at the site rrnB T1 transcription termination signal were made in the presence the lysozyme. The results shows that the transcription elongation complexes are unstable in the presence of T7 phage lysozyme.

• Bulletin of the Korean Chemical Society
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• v.34 no.2
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• pp.600-608
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• 2013

Amide analogs of tridecapeptide ${\alpha}$-factor (WHWLQLKPGQPMYCONH$_2$) of Saccharomyces cerevisiae, in which Trp at position 1 and 3 were replaced with other residues, were synthesized to ascertain whether cooperative interactions between two Trp residues occurred upon binding with its receptor. Analogs containing Ala or Aib at position 3 of the peptide $[Ala_3]{\alpha}$-factor amide (2) and $[Aib_3]{\alpha}$-factor amide (5) exhibited greater decreases in bioactivity than analogs with same residue at position one $[Ala^1]{\alpha}$-factor amide (1) and $[Aib^1]{\alpha}$-factor amide (4), reflecting that $Trp^3$ may plays more important role than $Trp^1$ for agonist activity. Analogs containing Ala or Aib in both position one and three 3, 6 exhibited complete loss of bioactivity, emphasizing both the essential role and the combined role of two indole rings for triggering cell signaling. In contrast, double substituted analog with D-Trp in both positions 9 exhibited greater activity than single substituted analog with D-Trp 8 or deleted analog 7, reflecting the combined contribution of two tryptophane residues of ${\alpha}$-factor ligand to activation of Ste2p through interaction with residue $Tyr^{266}$ and importance of the proper parallel orientation of two indole rings for efficient triggering of signal G protein coupled activation. Among ten amide analogs, $[Ala^{1,3}]{\alpha}$-factor amide (3), $[Aib^{1,3}]{\alpha}$-factor amide (6), [D-$Trp^3]{\alpha}$-factor amide (8) and [des-$Trp^1,Phe^3]{\alpha}$-factor amide (10) were found to have antagonistic activity. Analogs 3 and 6 showed greater antagonistic activity than analogs 8 and 10.