• Journal of Microbiology and Biotechnology
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• 제18권2호
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• pp.219-227
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• 2008

The free-living photoheterotrophic Gram-negative bacterium Rhodobacter sphaeroides possesses a quorum-sensing (QS) regulatory system mediated by CerR-CerI, a member of the LuxR-LuxI family. To identify the genes affected by the regulatory system, random lacZ fusions were generated in the genome of R. sphaeroides strain 2.4.1 using a promoter-trapping vector, pSG2. About 20,000 clones were screened and 23 showed a significantly different level of ${\beta}$-gal activities upon the addition of synthetic 7,8-cis-N-tetradecenoyl-homoserine lactone (RAI). Among these 23 clones, the clone showing the highest level of induction was selected for further study, where about a ten-fold increase of ${\beta}$-gal activity was exhibited in the presence of RAI and induction was shown to be required for cerR. In this clone, the lacZ reporter was inserted in a putative gene that exhibited a low homology with catD. A genetic analysis showed that the expression of the catD homolog was initiated from a promoter of another gene present upstream of the catD. This upstream gene showed a strong homology with luxR and hence was named qsrR (quorum-sensing regulation regulator). A comparison of the total protein expression profiles for the wild-type cells and qsrR-null mutant cells using two-dimensional gel electrophoresis and a MALDI-TOF analysis allowed the identification of sets of genes modulated by the luxR homolog.

• 대한수의학회지
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• 제54권1호
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• pp.39-48
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• 2014

The prevalence of thermophilic Campylobacter (C.) spp. in stray, breeding, and household dogs was 25.2, 12.0, and 8.8%, respectively. C. jejuni and C. upsaliensis were the predominant Campylobacter spp. from household dogs. cdtA, cdtB, and cdtC were detected by PCR in all isolates. Despite the high cytolethal distending toxin (CDT) gene prevalence, only 26 (31%) C. jejuni strains and one (15.3%) C. coli strain showed evidence of CDT production in HEp-2 cell cytotoxicity assays. Virulence-associated genes detected in the C. jejuni and C. coli isolates were cadF, dnaJ, flaA, racR, ciaB, iamA, pldA, virB11, ceuE, and docC. cadF, dnaJ, flaA, and ceuE were found in all C. jejuni and C. coli isolates. When detecting Guillain-Barr$\acute{e}$ syndrome-associated genes (galE, cgtB, and wlaN), galE was identified in all isolates. However, cgtB and wlaN were more prevalent in C. jejuni isolates from humans than those from dogs. Adherence and invasion abilities of the C. jejuni and C. coli strains were tested in INT-407 cells. A considerable correlation (adjusted $R^2$= 0.678) existed between adherence and invasion activities of the Campylobacter spp. isolates.

• Reproductive and Developmental Biology
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• 제28권1호
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• pp.71-76
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• 2004

Gene delivery is one of the keen interests in animal industry as well as research on gene functions. Some of the in vivo gene delivery techniques have been successively used in various tissues for the gene therapy and transgenesis. Despite intensive efforts, it still remains to overcome problems of limited local and regional administration and low transgene expression. To improve the efficiency of gene delivery, a new procedure was tested. We injected exogenous DNA containing LacZ into the female or male gonads and then pulsed electric field. Electroporated gonads showed positive X-gal staining in many seminiferous tubules of the porcine fetal gonads. Exogenously introduced LacZ genes were also expressed in female porcine gonad. In addition, we demonstrated efficient gene delivery in gonad of adult mouse. Furthermore, we succeed to generate genetically modified germline cells showing GFP and positive X-gal signals. The results suggest that the newly developed gene delivery is an effective way of in vivo transfection in mammals. The developed gene delivery procedure should be useful in producing transgenic animals when combined with primary cell culture and nuclear transplantation.

• 한국식품영양학회지
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• 제32권2호
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• pp.106-113
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• 2019

The objective of this study was to evaluate the effect of fermented Kalopanax pictus (KP-F) on macrophage activation and its effect as a competitive inhibitor of LPS and inhibitory effect on endotoxemia. The results showed that KP-F could activate macrophage in a dose-dependent manner, and KP-F was confirmed to act as a ligand for TLR4. Also, it was found that KP-F did not exhibit the same biotoxicity as LPS in intraperitoneal injection, and that it could suppress the neutrophil migration induced by LPS administration. In normal mice, the body weight, tissue weight, and amount of nitrite and pro-inflammatory cytokines in serum showed no significant changes with KP-F diet for 2 weeks, confirming that administration of KP-F in normal mice did not lead to over activation of immune response and biotoxicity. In the mouse model of endotoxemia induced by LPS and D-galactosamine(D-GalN) in sub-lethal dose, the diet of KP-F effectively inhibited the amount of nitrite and cytokines in the blood, and thus was found to be able to relieve the hepatic and kidney injury. In addition, in the endotoxemia mouse model induced by LPS and D-GalN of lethal dose, the survival rate was increased by KP-F diet in a dose-dependent manner.

• 대한두경부종양학회지
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• 제14권1호
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• pp.88-93
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• 1998

In order to review the clinicopathologic characteristics of the thyroid cancer associated with benign thyroid disease, we evaluated 47 patients treated between January, 1993 and September, 1997 at the Chonnam National University Hospital. In those period, we had operated a total of 690 thyroidectomy of which 320 were diagnosed as thyroid cancer. Forty three(91.4%)occurred in women and four(8.5%)occurred in men. The mean age at operation was 46.7years(range, 15 to 76 years). Forty three of the 47 cancers(91.4%) were papillary carcinomas while 4(8.5%)were follicular. Twenty four of the 47 patients (51%) were occult thyroid carcinomas measured less than 1 cm in diameter. The concurrent benign disease were nodular goiter(n=17), Hashimoto's thyroiditis(n=16), follicular adenoma(n=10), Graves' disease(n=2) and diffuse hyperplasia(n=2). Thirty one patients were diagnosed by preoperative FNAC and they underwent total thyroidectomy. Three were diagnosed by frozen section examination at the time of operation. Among them, one underwent total thyroidectomy and two underwent subtotal thyroidectomy. Eight cases revealed lymph node metastases and 2 cases extended to surrounding muscles. In conclusion, concurrent thyroid cancers and benign thyroid disease are not uncommon and a regular ultrasonic follow-up with selective aspiration cytologic examination is recommaned to enhance their diagnostic accuracy.

• Biotechnology and Bioprocess Engineering:BBE
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• 제7권1호
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• pp.38-42
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• 2002

A chitinase gene (pCHi58) encoding a 58 kDa chitinase was isolated from the Serratia marcescens KCTC 2172 cosmid library. The chitinase gene consisted of a 1686 bp open reading frame that encoded 562 amino acids. Escherichia coil harboring the pChi58 gene secreted a 58 kDa chitinase into the culture supernatant. The 58 kDa chitinase was purified using a chitin affinity column and mono-S column. A nucleotide and N-terminal amino acid sequence analysis showed that the 58 kDa chitinase had a leader peptide consisting of 23 amino acids which was cleaved prior to the 24th alanine. The 58 KDa chitinase exhibited a $98\%$ similarity to that of S. marcescens OMB 1466 in its nuclotide sequence. The chitinolytic patterns of the 58 kDa chitinase released N,N'-diacetyl chitobiose (NAG2) as the major hydrolysis end-product with a trace amount of N-acetylglucosamine. When a 4-methylumbellyferyl-N-acetylglucosamin monomer, dimmer, and tetramer were used as substrates, the 58 kDa chitinase did not digest the 4-Mu-NAG monomer $(analogue\;of\;NAG_2)$, thereby indicating that the 58 kDa chitinase was likely an endochitinase. The optimum reaction temperature and pH of the enzyme were $50^{\circ}C$ and 5.0, respectively.

• Macromolecular Research
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• 제12권4호
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• pp.407-412
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• 2004

A new hydroxyl group-containing conjugated ionic polymer, poly[2-ethynyl-N-(p-hydroxyphenylethyl)pyridinium bromide], was synthesized by the activated polymerization of 2-ethynylpyridine with p-(2-bromoethyl) phenol without any additional initiator or catalyst. The polymerization proceeded well to give a moderate yield (65%) of polymer at a reaction temparature of 90$^{\circ}C$. Another polymer, poly[2-ethynyl-N-(p-hydroxyphenylethyl)pyridinium tetraphenylborate], was readily prepared by the ion-exchange reaction of poly[2-ethynyl-N-(p-hydroxyphenylethyl)pyridinium bromide] with sodium tetraphenylborate. These polymers were completely soluble in organic solvents such as DMF, DMSO, and acetone, but insoluble in water and ether. Instrumental analyses, such as NMR, IR, and UV-Vis spectroscopies, indicated that the new materials have conjugated polymer backbone systems with the designed substituents and counter anions. X-Ray diffraction analyses of the polymers indicated that they were mostly amorphous.

• Korean Membrane Journal
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• 제9권1호
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• pp.1-11
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• 2007

To prepare chemically stable asymmetric microporous membranes with a hydrophilic surface, which would be expected to have better antifouling properties, poly(vinylidene fluoride) (PVDF) blend membranes were prepared by the phase inversion process. PVDF mixture solutions in N-methylpyrrolidone (NMP) blended with several polar potential ionic polymers such as polyacrylonitrile (PAN), poly(methylmethacrylate) (PMMA) and poly(N-isopropylacrylamide) (NIPAM) were used for the formation of the PVDF blend membranes. They were then characterized with several analytical methods such as FESEM, FTIR, contact angle measurement, pore size distribution and permeability measurement. Regardless of different polar polymers blended, they all showed a finger-like structure with more hydrophilic surface than the pristine PVDF membrane. For all the PVDF blend membrane, due to the polar potential ionic polymers used, the flux of those was improved. Especially the PVDF blend membrane with NIPAM showed the highest flux among the membranes prepared. Also antifouling property of the PVDF membrane was improved by the use of the polar polymers.

• Bulletin of the Korean Chemical Society
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• 제13권6호
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• pp.625-627
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• 1992

This article deals with the synthesis and characterization of poly [N-(propargyloxy)phthalimide][poly (POPI)]. The polymerization of POPI was carried out by various transition metal catalysts. $MoCl_5$-based catalysts were found to be more effective than $WCl_6$-based catalysts. However, the polymer yield was relatively low (maximum 35%). The polymerization of POPI by $PdCl_2$ gave poly (POPI) in fair yields in DMF and pyridine. The resulting poly (POPI)s were mostly insoluble in organic solvents. The infrared spectrum of poly (POPI) showed no peak at 2135 $cm^{-1}$ due to acetylenic $C{\equiv}C$ stretching frequency. Instead, the carbon-carbon double bond stretching frequency was observed at 1600-1650 $cm^{-1}$. The TGA thermogram showed that the present poly (POPI) is thermally stable up to $160^{\circ}C.$.

• 생명과학회지
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• 제18권6호
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• pp.782-788
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• 2008

경골어류 4종(조피볼락, 용치놀래기, 송곳니베도라치 및 졸복) 장관의 복합당질 성상의 차이를 밝히기 위해 장을 네 부위로 나누워 아홉 종류의 biotinylated lectin들(DBA, SBA, PNA, BSL- I , RCA- I , sWGA, UEA- I 및 Con A)로 반응시켰다. 조피볼락을 제외하면 부위에 따른 차이는 없었다. 용치놀래기 장 상피는 모든 부위에서 D-glucose/mannose 잔기를 함유하고 있었다. 조피볼락, 송곳니베도라치 및 졸복 장 모든 부위에서는 정도의 차이는 있지만 ${\beta}$-N-acetyl-D-gal-actosamine가 함유되어 있었다. 또한 조피볼락의 근위장, 중간장 및 원위장에는 galactose-${\beta}$-1,3-N-acetyl-D-galactosamine 및 ${\alpha}$-D-galactose도 함유되어 있었으나 직장에는 이들 당 잔기들이 함유되어 있지 않았다. 송곳니베도라치에는 ${\beta}$-N- acetyl-D-galactosamine 외에 ${\beta}$-N-acetyl-D-glucosamine 및 D-glucose/mannose도 발견되었으며, 졸복에서는 Galactose-${\beta}$-1,3-N-acetyl-D-galactosamine, D-galactose 및 D-glucose/mannose도 발견되었다.