• Bulletin of the Korean Chemical Society
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• v.26 no.2
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• pp.285-291
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• 2005

The nonstructural protein 5B (NS5B) of hepatitis C virus (HCV) is the viral RNA-dependent RNA polymerase (RdRp), which is the essential catalytic enzyme for the viral replication and is an appealing target for the development of new therapeutic agents against HCV infection. A small amount of serum from a single patient with hepatitis C was used to get the genome of a Korean HCV isolate. Sequence analysis of NS5B 1701 nucleotides showed the genotype of a Korean isolate to be subtype 1b. The soluble recombinant HCV NS5B polymerase lacking the C-terminal 24 amino acids was expressed and purified to homogeneity. With the highly purified NS5B protein, we established in vitro systems for RdRp activity to identify potential polymerase inhibitors. The rhodanine family compounds were found to be potent and specific inhibitors of NS5B from high throughput screening (HTS) assay utilizing the scintillation proximity assay (SPA) system. The binding mode of an inhibitor was analyzed by measuring various kinetic parameters. Lineweaver-Burk plots of the inhibitor suggested it binds not to the active site of NS5B polymerase, but to an allosteric site of the enzyme. The activity of NS5B in in vitro polymerase reactions with homopolymeric RNA requires interaction with multiple substrates that include a template/primer and ribonucleotide triphosphate. Steady-state kinetic parameter, such as Km, was determined for the ribonucleotide triphosphate. One of compounds found interacts directly with the viral polymerase and inhibits RNA synthesis in a manner noncompetitively with respect to UTP. Furthermore, we also investigated the ability of the compound to inhibit NS5B-directed viral RNA replication using the Huh7 cell-based HCV replicon system. The investigation is potentially very useful for the utility of such compounds as anti-hepatitic agents.

• Bulletin of the Korean Chemical Society
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• v.31 no.9
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• pp.2509-2513
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• 2010

In order to increase protease stability of a novel Trp-rich model antimicrobial peptide, $K_6L_2W_3$ (KLWKKWKKWLK-$NH_2$)and investigate the effect of L-amino acid to peptoid residue conversion on biological functions, we synthesized its antimicrobial peptoid, $k_6l_2w_3$. Peptoid $k_6l_2w_3$ had similar bacterial selectivity compared to peptide $k_66L_2W_3$. The bactericidal rate of $k_6l_2w_3$ was somewhat slower than that of $K_6L_2W_3$. Peptoid $k_6l_2w_3$ exhibited very little dye leakage from bacterial outer-membrane mimicking PE/PG liposomes, as observed in $K_6L_2W_3$, indicating that the major target site of $K_6L_2W_3$ and $k_6l_2w_3$ may be not the cell membrane but the cytoplasm of bacteria. Trypsin treatment of $K_6L_2W_3$ completely abolished antimicrobial activities against Escherichia coli and Staphylococcus aureus. In contrast, the antimicrobial activity of $k_6l_2w_3$ was completely preserved after trypsin treatment. Taken together, our results suggested that antimicrobial peptoid $k_6l_2w_3$ can potentially serves as a promising therapeutic agent for the treatment of microbial infection.

• YAKHAK HOEJI
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• v.48 no.2
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• pp.159-164
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• 2004

Primary pro-inflammatory cytokines are a trio: tumor necrosis- $\alpha$ (TNF-$\alpha$), interleukine-$\beta$ (IL-$\beta$), and interleukine-6 (IL-6). These cytokines initiate and regulate the acute-phase inflammatory response during infection, trauma, or stress and appear to play an important role in the immune process. Nitric oxide (NO) is a multi-functional mediator, which plays an important role in regulating various biological functions in vivo. NO production by inducible nitric oxide synthase (iNOS) in macrophages is essential for the defense mechanisms against microorganisms and tumor cells. However, over-expression of iNOS by various stimuli, resulting in over-production of NO, contributes to the pathogenesis of septic shock and some inflammatory and auto-immune disease. Solvent fractions of sage ( Salvia officinalis L.), which is cultivated in Jeju-Do, was assayed for their effects on TNF-$\alpha$ and IL-6 production in LPS-stimulated RAW 264.7 macrophages. Hexane and ethylacetate (EtOAc) fraction of sage inhibited the protein and mRNA expression of TNF-$\alpha$ and IL-6 in LPS stimulated RAW 264.7 cells at the concentration of 100 $\mu\textrm{g}$/$m\ell$. Also, incubation of RAW 264.7 cells with the fraction of hexane or EtOAc (50 $\mu\textrm{g}$/$m\ell$) inhibited the LPS induced nitrite accumulation and the LPS/IFN-${\gamma}$ induced iNOS protein. And this inhibition of iNOS protein is concordant with the inhibition of iNOS mRNA expression. Above results suggest that extract of sage may have anti-inflammatory activity through the inhibition of pro-inflammatory cytokines (TNF-$\alpha$, IL-1$\beta$, IL-6), iNOS and NO.

• The Journal of Korean Society of Virology
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• v.27 no.2
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• pp.151-160
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• 1997

In view of the potential of replicase protein as a diagnostic reagent for human caliciviruses (HuCVs), we have cloned and over-expressed this gene from the Snow Mountain-like Korean strains in Escherichia coli as a fusion protein with glutathione S-transferase (GST), and described the preliminary antigenic characterization of the recombinant products. Each 470bp fragment corresponding to highly conserved region of RNA-dependent RNA polymerase was generated by RT-PCR from stools of two diarrheal children, cloned in pMOSBlue T-vector, and subcloned between the EcoRI and SalI restriction sites of pGEX-4T-3, a GST gene fusion vector, yielding $pGCV_{pol}$. This construct expressed a Snow Mountain-like HuCV replicase under the control of the IPTG-inducible tac promoter. An extract prepared by sonication of the E. coli cell inclusion bodies bearing $pGCV_{pol}$ products was purified and analyzed by SDS-PAGE. After Coomassie blue staining, it was shown that the recombinant replicase migrated on the gels with an approximate molecular mass of 46.5 kDa, that was subsequently cleaved into a 26 kDa GST fragment and a 20.5 kDa replicase protein upon digestion with thrombin protease. The replicase was recognized on immunoblotting with the sera from symptomatic children with the HuCV-associated diarrhea but not by asymptomatic sera from adults. The results presented the first biological activity of individually expressed HuCV replicase subunit and provided important reagents for diagnosis of HuCV infection.

• Parasites, Hosts and Diseases
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• v.53 no.6
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• pp.689-697
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• 2015

The tapeworm Taenia solium is an important human zoonotic parasite that causes great economic loss and also endangers public health. At present, an effective vaccine that will prevent infection and chemotherapy without any side effect remains to be developed. In this study, codon usage patterns in the T. solium genome were examined through 8,484 protein-coding genes. Neutrality analysis showed that T. solium had a narrow GC distribution, and a significant correlation was observed between GC12 and GC3. Examination of an NC (ENC vs GC3s)-plot showed a few genes on or close to the expected curve, but the majority of points with low-ENC (the effective number of codons) values were detected below the expected curve, suggesting that mutational bias plays a major role in shaping codon usage. The Parity Rule 2 plot (PR2) analysis showed that GC and AT were not used proportionally. We also identified 26 optimal codons in the T. solium genome, all of which ended with either a G or C residue. These optimal codons in the T. solium genome are likely consistent with tRNAs that are highly expressed in the cell, suggesting that mutational and translational selection forces are probably driving factors of codon usage bias in the T. solium genome.

• Korean Journal of Veterinary Pathology
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• v.3 no.1
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• pp.35-44
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• 1999

The morphologic changes of small intestinal epithelium in pigs diagnosed as porcine epidemic diarrhea(PED} by virus isolation and immunohistochemistry were studied through light microscope and transmissible electron microscope. On semi-thin section, the histologic findings showed severe villous atrophy and fusion with hyperplasia of cuboidal epithelium in the villi, inflammatory cell infiltration in lamina propria, and increased mitotic figures in the crypt. The structural changes were mostly restricted to the cytoplasm of affected absorptive epithelium of villi. 3 types of epithelial changes were found; degenerated virus-affected cells, undifferentiated cuboidal cells, and normal columnar cells. On electron microscopy, round to spherical viral particles of 50∼l00nm in diameter were found within the dilated vesicles and endoplasmic reticulums of degenerated cells, which had decreased their cytoplasmic electron density due to dilated and missing organelles(e.g. mitochondria, ERs, etc.). Microvilli were shortened and sparse, leaving denuded terminal web of the villous epithelial cells. Fat globules were often found within slightly degenerated enterocytes. On the tip of villi, severely damaged cells were exfoliated and replaced by undifferentiated cuboidal cells We found distinct ultrastructural changes in the jejunal epithelium confirming PED virus infection is involved in malabsorptive diarrhea.

• Korean Journal of Veterinary Research
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• v.44 no.1
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• pp.73-82
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• 2004

Chitosan is similar in structure to cellulose and are the second most abundant polysaccharides in nature, comprising the horny substance in the exoskeletons of crabs, shrimp and insects as well as fungi. This study was conducted to access the effect of immunomodulation responses of chitosan(N-acetyl-${\beta}$-D-glucosamine) chicken infected with in Fowl typhoid(Salmonella gallinarum). One-day-old broiler chicks were divided into eight groups: The 1st group was inoculated intra-peritoneally with chitosan and challenged intra-peritoneally with S. gallinarum. The 2nd group was inoculated intra-peritoneally with chitosan. The 3rd group was feeding with chitosan and intra-peritoneally inoculated with cyclophosphamide and challenged intra-peritoneally S. gallinarum. The 4th group was feeding with chitosan and intra-peritoneally with cyclophosphamide. The 5th group was feeding with chitosan and challenged intra-peritoneally with S. gallinarum. The 6th group was feeding with chitosan. The 7th group was challenged intra-peritoneally with S. gallinarum. The 8th group was nontreated-uninfected control group. The results shows that $CD4^+$, $CD8^+$ and B lymphocyte in lymphoid organs of chickens treated with chitosan increased in especially $CD4^+$, $CD8^+$ lymphocytes (p<0.05). The group of feeding chitosan showed the significantly increased $CD4^+$, $CD8^+$ and B lymphocyte than inoculated intra-peritoneally with chitosan. As the result suggests that the feeding of chitosan induced immunostimulatant effect than the inoculation intra-peritoeally of chitosan.

• Journal of Chest Surgery
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• v.31 no.7
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• pp.725-729
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• 1998

Endobronchial leiomyoma is extremely rare and accounts for less than 2% of benign tumors of the lower respiratory tract. Leiomyomas are predominantly found in the young and the middle aged : of the average age being 35 years for bronchial and lung parenchymal lesions and 40.6 years for tracheal lesions. The symptom depends on the location of the tumor, its size, and changes in the lung distal to the lesion. A 37-year-old woman was admitted to our hospital complaining of coughing. Bronchoscopy revealed complete obstruction of the right main bonchus at the carina by an oval-shaped, nonulcerative, smooth, and pinkish-tan tumor with a broad margin and extended to the left main bronchus. A biopsy was performed and showed a benign spindle cell tumor. A right pneumonectomy was performed because of chronic infection, and the lung could not expanded during aeration. The histological diagnosis of the resected specimen was leiomyoma. The postoperative course was uneventful.

• Journal of Dental Anesthesia and Pain Medicine
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• v.18 no.4
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• pp.223-233
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• 2018

Topical anesthetics are commonly used in oral & maxillofacial surgery to control pain in the oral cavity mucosa before local anesthetic injection. These anesthetic agents come in many forms, developed for different usages, to minimize adverse reactions, and for optimal anesthetic efficiency. Earlier studies have revealed that these agents may also limit the growth of microorganisms in the area of anesthetic application. Many topical anesthetic agents show different levels of antimicrobial activity against various bacterial strains and Candida. The dosage of local anesthetic agent used in some clinical preparations is too low to show a significant effect on microbial activity. Efficiency of antimicrobial activity depends on the local anesthetic agent's properties of diffusion within the bloodstream and binding efficiency with cytoplasmic membrane, which is followed by disruption of the bacterial cell membrane. The antimicrobial properties of these agents may extend their usage in patients to both control pain and infection. To develop the topical local anesthetic optimal usage and antimicrobial effect, a collaborating antiseptic agent may be used to benefit the local anesthetic. However, more research is required regarding minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) of topical local anesthetic agents with drug interaction between anesthetics and antiseptic agents.

• Journal of Yeungnam Medical Science
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• v.23 no.2
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• pp.152-161
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• 2006

Carcinoma of the gallbladder is an uncommon but highly malignant tumor with a poor five year survival rate. Early detection is very important for successful treatment because this tumor is very hard to cure in cases where it has advanced beyond the reach of surgical treatment. The purpose of this review was to evaluate risk factors for carcinoma of the gallbladder and determine the best management approach.. Solitary polys, more than one cm are considered to be predisposing factors for gallbladder carcinoma when they are found to be echopenic, sessile, and with a high cell density. Anomalous union of the pacreato-biliary duct(AUPBD) without a choledochal cyst is also considered to increase risk for gallbladder carcinoma. A polyps size of more than one cm and an AUPBD are indications for prophylactic cholecystectomy. The presence of gallstones is a well-established risk factor for the development of gallbladder carcinoma; risk appears to correlate with the stone size and the duration of chronic cholecystitis. Metaplastic changes of the gallbladder epithelium present with chronic cholecystitis and may indicate a premalignant lesion. Abnormal forms of cholecystitis such as xanthogranulomatous or a porcelain gallbladder also have malignant potential; cholecystoenteric fistula as well as bacterial infection of the gallbladder(typhoid, helicobacter species) also has malignant potential. In this review, the risk factors associated with carcinoma of the gallbladder are summarized with special attention to gallstones, polyps, AUPBD, and chronic inflammation.