• 대한핵의학회:학술대회논문집
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• 2001.05a
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• pp.66-75
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• 2001

Although diverse mechanisms are involved in multidrug resistance for chemotherapeutic drugs, the development of cellular P-glycoprotein(Pgp) and multidrug-resistance associated protein (MRP) are important factors in the chemotherapy failure to cancer. Various detection assays provide information about the presence of drug efflux pumps at the mRNA and protein levels. However these methods do not yield information about dynamic function of Pgp and MRP un vivo. Single photon emission tomography (SPECT) and positron emission tomography (PET) are available for the detection of Pgp and MRP-mediated transport. $^{99m}Tc$-sestaMIBl and other $^{99m}Tc$-radiopharmaceuticals are substrates for Pgp and MRP, and have been used in clinical studies for tumor imaging, and to visualize blockade of Pgp-mediated transport after modulation of Pgp pump. Colchicine, verapamil and daunorubicin labeled with $^{11}C$ have been evaluated for the quantification of Pgp-mediated transport with PET in vivo and reported to be feasible substrates with which to image Pgp function in tumors. Leukotrienes are specific substrates for MRP and N-$[^{11}C]$acetyl-leukotriene E4 provides an opportunity to study MRP function non-invasively in vivo. Results obtained from recent publications are reviewed to confirm the feasibility of using SPECT and PET to study the functionality of MDR transporters in vivo.

• Food Science of Animal Resources
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• v.29 no.5
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• pp.590-598
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• 2009

The aim of this study was to model and optimize the calcium alginate (CA) and microbial transglutaminase (TG) systems to form a cold-set myofibrillar protein (MP) gel containing 0.1 M or 0.3 M NaCl using a response surface methodology. The gel strengths of cold-set and heat-induced MP gels, and cooking yields were measured. All measured parameters showed determination coefficients ($R^2$) above 0.7 without a lack-of-fit. The CA system had the best results with component ratios of 1.0:0.3:1.0 corresponding to sodium alginate, calcium carbonate and glucono-$\delta$-lactone, respectively, and was favourable at 0.1 M NaCl. In contrast, the TG system only had an effect on cold-set MP gelation at 0.3 M salt, and the optimal ratio of TG to sodium caseinate was 0.6:0.5. By combining the two systems at 0.3 M NaCl, an acceptable cold-set MP gel with an improved texture and high cooking yield could be formed. Therefore, these results indicated that the functionality of the cold-set MP gel could be enhanced by combining these two optimized gelling system.

• Biomolecules & Therapeutics
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• v.25 no.1
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• pp.69-79
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• 2017

Viruses continue to evolve a new strategy to take advantage of every aspect of host cells in order to maximize their survival. Due to their central roles in transducing a variety of transmembrane signals, GPCRs seem to be a prime target for viruses to pirate for their own use. Incorporation of GPCR functionality into the genome of herpesviruses has been demonstrated to be essential for pathogenesis of many herpesviruses-induced diseases. Here, we introduce US28 of human cytomegalovirus (HCMV) as the best-studied example of virally-encoded GPCRs to manipulate host GPCR signaling. In this review, we wish to summarize a number of US28-related topics including its regulation of host signaling pathways, its constitutive internalization, its structural and functional analysis, its roles in HCMV biology and pathogenesis, its proliferative activities and role in oncogenesis, and pharmacological modulation of its biological activities. This review will aid in our understanding of how pathogenic viruses usurp the host GPCR signaling for successful viral infection. This kind of knowledge will enable us to build a better strategy to control viral infection by normalizing the virally-dysregulated host GPCR signaling.

• Animal cells and systems
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• v.7 no.3
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• pp.207-211
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• 2003

Caveolin-1 is a principal protein in the plasma membrane microdomains called caveolae. Caveolae play an important role in the transcytosis and pinocytosis. Therefore, caveolin-1 is most likely to work for the membrane dynamic events. In addition, caveolin-1 interacts with various signaling molecules. Although caveolin-1 possesses a variety of physiological functions, its structural properties were little construed. Here we analyzed the structural dynamics of the N-terminal caveolin-1 (residues 1-101), in order to better understand the structural properties in terms of its versatile functionality. We first analyzed its oligomeric form using GST-fused N-terminal domain, revealing that it equilibrates between a dimer and monomers in av concentration-dependent manner. The N-terminal domain of caveolin-1 was previously found to form a heptamer, so that our data suggest the dimeric form as an intermediate structure for the heptamer formation. Then, we obtained the folding profile, which indicated that $\DeltaG_{H2O}\;is\;about\;0.5\;\pm0.03$ kcal/mol. The stability of N-terminal domain is relatively low, indicating that N-terminal domain may not be crystalline. Conclusively, the dynamic and flexible structure of N-terminal domain appears more favorable to maintain the versatile functions of caveolin-1.

• Molecules and Cells
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• v.27 no.2
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• pp.237-241
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• 2009

Pathogens Burkholderia pseudomallei (Bp) and Burkholderia mallei (Bm) contain a large number (> 12,000) of Simple Sequence Repeats (SSRs). To study the extent to which these features have contributed to the diversification of genes, we have conducted comparative studies with nineteen genomes of these bacteria. We found 210 genes with characteristic types of SSR variations. SSRs with nonamer repeat units were the most abundant, followed by hexamers and trimers. Amino acids with smaller and nonpolar R-groups are preferred to be encoded by the variant SSRs, perhaps due to their minimal impacts to protein functionality. A majority of these genes appears to code for surface or secreted proteins that may directly interact with the host factors during pathogenesis or other environmental factors. There also are others that encode diverse functions in the cytoplasm, and this protein variability may reflect an extensive involvement of phase variation in survival and adaptation of these pathogens.

• Preventive Nutrition and Food Science
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• v.7 no.3
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• pp.327-331
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• 2002

Tea is a pleasant, popular and safe beverage in the world. During the past decade, epidemiological studies have shown that tea catechins intake is associated with lower risk of cardiovascular disease. Tea provides a dietary source of health-promoting components to help humans reduce a wide variety of cancer risks and chronic diseases. The antioxidative activity of tea-derived catchins has been extensively studied. The antioxidant effect is a synergistic action between catechins e.g. EGCG, EGC, ECG, EC, pheophytins a and b, and other components in tea leaves, which aye more bioavailable for human body. Green tea has a Higher content of catechins than other kinds of tea. Green tea extract with hot water has high potential and more efficiency to reduce cancer risk than any other tea products or pure EGCG. Protein, iyon, and other food components may interfere with the bioavailability of ten catechins. Interaction of catechins with drug affects the cancer-preventive activity of some cancer-fighting medication. Further studies are required to determine the bioavailability of tea catechins and cancer-preventive functionality.

• Journal of Microbiology and Biotechnology
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• v.17 no.3
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• pp.408-413
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• 2007

Putrescine has a negative effect on health and is also used as an indicator of quality on meat products. We investigated the genes involved in putrescine production by Serratia liquefaciens IFI65 isolated from a spoiled Spanish dry-cured ham. We report here the genetic organization of its ornithine decarboxylase encoding region. The 5,506-bp DNA region showed the presence of three complete and two partial open reading frames. Putative functions have been assigned to several gene products by sequence comparison with proteins included in the databases. The second gene putatively coded for an ornithine decarboxylase. The functionality of this decarboxylase has been experimentally demonstrated by complementation to an E. coli defective mutant. Based on sequence comparisons of some enterobacterial ornithine decarboxylase regions, we have elaborated a hypothetical pathway for the acquisition of putrescine biosynthetic genes in some Enterobacteriaceae strains.

• Preventive Nutrition and Food Science
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• v.2 no.1
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• pp.17-22
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• 1997

Casein was chemically modified with acetic, succinic, and maleic anhydride and changes in functional pro-perties were evaluated as affected by the degree of modification. Chemical modification resulted in casein with unique functional properties depending upon the type of anhydrid used and the degree of modification. It was possible to control heat coagulation, calcium precipitability, forming and emulsion capacity and stability. At pH 4.5 heat coagulation was 0% in the case 74.1% acetylated casein; on the contrary, succinylation and maleyation resulted in highly heat sensitive protein. Foaming properties were improved markedly by suc-cinylation and maleylation at pH 4.5. However, emulsifying properties were enhanced only by maleylation.

• Natural Product Sciences
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• v.19 no.1
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• pp.1-7
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• 2013

AMP-activated protein kinase (AMPK) is a major cellular energy sensor and master regulator of metabolic homeostasis. On activation, this cellular fuel sensing enzyme induces a series of metabolic changes to balance energy consumption via multiple downstream signaling pathways controlling nutrient uptake and energy metabolism. This pivotal role of AMPK has led to the development of numerous AMPK activators which might be used as novel drug candidates in the treatment of AMPK related disorders, diabetes, obesity, and other metabolic diseases. Consequently, a number of patents have been published on AMPK activators from natural products and other sources. This review covers the patented AMPK activators from natural products and their therapeutic potential in treatment or prevention of metabolic diseases including diabetes and obesity.

• Journal of the Korean Society of Food Culture
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• v.28 no.6
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• pp.657-663
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• 2013

This study analyzed fish paste containing Lagocephalus lunaris powder (LLP). The moisture, crude ash, crude protein, and crude lipid content of LLP were 6.21%, 1.03%, 74.50%, and 1.21% respectively. The tested concentrations of LLP were 0, 3, 5, and 7%. The pH of the samples ranged from 6.75 to 6.89, and moisture content ranged from 75.23% to 76.95%. The L values of the samples decreased as the concentrations of LLP decreased, and the a and b values increased. In addition, the folding test results in all test samples were "AA", indicating a good mean flexibility. In the texture meter test, the hardness, strength, springiness, gumminess, and chewiness increased according to increasing concentrations of LLP. In the sensory evaluation, the fish paste prepared with 5% LLP were preferred over other fish pastes. These results suggest that LLP can be applied to fish paste for substantially increasing its quality and functionality.