• Journal of Life Science
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• v.8 no.1
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• pp.40-50
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• 1998

Staphylococuus aureus and Escherichia coli is increasingly responsible for outbreaks of nosocomial infection around the world. Because serious infections due to these organisms currently necessiate use of non-$\beta$-lactam antimicrobial therapy and because strains is ofen resistant to many antimicrobial agents, infections with this organism are difficult to treat. Isolated strains from post operaton wounds of PNU hospital patient were tested for the antimicrobial susceptibility, resistant pattern and combined action to the 6 antibiotics. The minimal inhibitory concentraction of each antibiotic anc antibiotics combining in various ratios were measured by checkerboard dilution method. the synergism was determined through calculating the fractional inhibitory concentraction index (FICI). In case of S. aureus, 15 strains was shown to be highly sensitive to streptomycin and 13 strains to cephalothin. In case of E. coli, it is excellent senstitive 16 strains, sensitive 4 strains on cefoperazone, as like S. aureus, and thus the sensitive is most to be 66%. As the result of gaining MIC from S. aureus upon agar dilution method, MIC$_{50}$ was 8$\mu$g/ml, MIC$_{90}$ was 16$\mu$g/ml and thus the streptomycine is shown to be lowest. In case of E, coli, S. MIC$_{50}$ was 4$\mu$g/ml, MIC$_{90}$ was 16$\mu$g/ml, in streptomycin and thus is shown to be lower than S. aureus. As the result of comparing the resistance aspect of combining the antibiotics on S. aureus and E. coli, the resistant strain can be known to be reduced to the large range more than each 40% than combining with only aminoglycoside-series or cephalosporine-series. As the result of combining aminoglycoside-series, streptomycin and cephalothin or cefuroxime sensitive to S. aureus and E. coli in the above mentioned results, the increase or imporovement of effect is over 73% and 80%, respectively, thus the case od combining 2 antibiotics is shown to be better in the effect. Isolated strains from operating wounds were for the antimicrobial susceptibility. In case of S. aureus 15 strains was shown to be sensitive very much on streptomycin. In case of E. coli it is excellent sensitive 16 strains. As the results of combining aminoglycosides-series, streptomycin and cephalosporine series, cephalothin and cefuroxime, the increase or improvement of effect is over 73%, thus case of combining 2 antibiotics is shown to be better in the effect.

• Korean Journal of Food Science and Technology
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• v.46 no.2
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• pp.121-126
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• 2014

Recently, infant formula products made of caprine milk have gained popularity, mainly because the nutritional composition of caprine milk is similar to that of human milk. In addition, caprine milk is considered to be better than bovine milk in terms of nutrient composition and easier digestion. Compared to bovine milk, caprine milk contains more ${\beta}$-casein, but less ${\alpha}$S1-casein. While the lactose concentration of both bovine and caprine milk is almost the same, a content of total oligosaccharides in caprine milk was approximately five to eight times higher than that in bovine milk. However, as the dairy goat industry in Korea is in a nascent stage of milk production and further processing, many nutritional advantages of caprine milk over bovine milk are not fully conveyed to general consumers. It is recommended that scientific research regarding the nutritional benefits of caprine milk needs to be conducted urgently, owing to the increasing domestic sales of infant formula products made of caprine milk.

• The Korean Journal of Physiology
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• v.28 no.1
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• pp.37-50
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• 1994

Synthetic potassium channel openers (KCOs) are agents capable of opening K-channels in excitable cells. These agents are known to have their maximal potency in the smooth muscle tissue, especially in the vascular smooth muscle. Much attention has been focused on the type of K-channel that is responsible for mediating the effects of KCOs. As the KCO-induced changes are antagonized by glibenclamide, an $K_{ATP}$ (ATP-sensitive K-channel) blocker in the pancreatic ${\beta}-cell,\;K_{ATP}$ was suggested to be the channel responsible. However, there also are many results in favor of other types of K-channel $$(maxi-K,\;small\;conductance\;K_{Ca,}\; SK_{ATP}) mediating the effects of KCOs. Effects of lemakalim, (-)enantiomer of cromakalim (BRL 34915), on the spontaneous contractions and slow waves, were investigated in the antral circular muscle of the guinea-pig stomach. Membrane currents and the effects on membrane currents and single channel activities were also measured in single smooth muscle cells and excised membrane patches by using the patch clamp method. Lemakalim induced hyperpolarization and inhibited spontaneous contractions in a dose-dependent manner. These effects were blocked by glibenclamide and low concentrations of tetraethyl ammonium (< mM). Glibenclamide blocked the effect of lemakalim on the membrane potential and slow waves. The mechanoinhibitory effect of lemakalim was blocked by pretreatment with glibenclamide. In a whole ceIl patch clamp condition, lemakalim largely increased outward K currents. These outward K currents were blocked by TEA, glibenclamide and a high concentration of intracelIular EGTA (10 mM). Volatage-gated Ca currents were not affected by lemakalim. In inside-out patch clamp experiments, lemakalim increased the opening frequency of the large conductance $Ca^{2+}-activated$ K channels $(BK_{Ca},\;Maxi-K).$ From these results, it is suggested that lemakalim induces hyperpolarization by opening K-channels which are sensitive to internal Ca and such a hyperpolarization leads to the inhibition of the spontaneous contraction.

• Korean Journal of Food Science and Technology
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• v.32 no.3
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• pp.726-735
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• 2000

This study was conducted to investigate the biological activities of polysaccharide extracted from the fruit body and cultured mycelia of Phellinus linteus IY001. All fractions were extracted by hot water, in the next, Fr. I, Fr. II, Fr. III and Fr. IV were polysaccharide obtained by ethanol precipitation or ultrafiltration. The highest antitumor activity against sarcoma 180 in ICR mice was observed in Fr. III and Fr. IV at the level 85%, but the antitumor activity had no connection with their anticomplementary activity in vitro, it might probably be due to extraction of hot water. All fractions promoted the production of nitric oxide and $TNF-{\alpha}$ in macrophage, addition of Fr. I and Fr. II resulted in production of nitric oxide$3(5.9{\sim}37.6\;{\mu}M)$ and of the $TNF-{\alpha}$ production($8,696.2{\sim}9,420pg/ml)$. All fractions inhibited the lipid peroxidation induced by $AsA/Fe^{2+}$, $ADP/NADPH/Fe^{3+}\;and\;CCl_4/NADPH$ in rat liver microsomes, and Fr. III showed the electron donating ability stronger than tocopherol in assay system using DPPH. From these results, it is suggested that all fractions contain immunoregulatory components which may protect cellular materials from the oxidative damages by their radical scavenging activities.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.34 no.1
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• pp.36-48
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• 2008

To repair bone defects in the oral and maxillofacial field, bone grafts including autografts, allografts, and artificial bone are used in clinical dentistry despite several disadvantages. The purpose of this study was to evaluate new bone formation and healing in rat calvarial bone defects using hydroxyapatite (HA, $Ca_{10}[PO_4]_6[OH]_2,\;Bongros^{(R)}$, Bio@ Co., KOREA) and tricalcium phosphate (${\beta}-TCP,\;Ca_3[PO_4]_2$, Sigma-Aldrich Co., USA) mixed at various ratios. Additionally, this study evaluated the effects of type I collagen (Rat tail, BD Biosciences Co., Sweden) as a basement membrane organic matrix. A total of twenty, 8-week-old, male Sprague-Dawley rats, weighing 250-300g, were divided equally into a control group (n=2) and nine experimental groups (n=2, each). Bilateral, standardized transosseous circular calvarial defects, 5.0 mm in diameter, were created. In each experimental group, the defect was filled with HA and TCP at a ratio of 100:0, 80:20, 70:30, 60:40, 50:50, 40:60, 30:70, 20:80, and 0:100 with or without type I collagen. Rats were sacrificed 4 and 8 weeks post-operation for radiographic (standardized plain film, Kodak Co., USA), histomorphologic (H&E [Hematoxylin and Eosin], MT [Masson Trichrome]), immunohistochemical staining (for BMP-2, -4, VEGF, and vWF), and elementary analysis (Atomic absorption spectrophotometer, Perkin Elmer AAnalyst $100^{(R)}$). As the HA proportion increased, denser radiopacity was seen in most groups at 4 and 8 weeks. In general radiopacity in type I collagen groups was greater than the non-collagen groups, especially in the 100% HA group at 8 weeks. No new bone formation was seen in calvarial defects in any group at 4 weeks. Bridging bone formation from the defect margin was marked at 8 weeks in most type I collagen groups. Although immunohistochemical findings with BMP-2, -4, and VEGF were not significantly different, marked vWF immunoreactivity was present. vWF staining was especially strong in endothelial cells in newly formed bone margins in the 100:0, 80:20, and 70:30 ratio type I collagen groups at 8 weeks. The calcium compositions from the elementary analysis were not statistically significant. Many types of artificial bone have been used as bone graft materials, but most of them can only be applied as an inorganic material. This study confirmed improved bony regeneration by adding organic type I collagen to inorganic HA and TCP mixtures. Therefore, these new artificial bone graft materials, which are under strict storage and distribution systems, will be suggested to be available to clinical dentistry demands.

• Journal of Periodontal and Implant Science
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• v.39 no.2
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• pp.119-128
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• 2009

Purpose: The aim of this study was to evaluate the stemness of cells from canine dental tissues and bone marrow. Methods: Canine periodontal ligament stem cells (PDLSC), alveolar bone stem cells (ABSC) and bone marrow stem cells(BMSC) were isolated and cultured. Cell differentiations (osteogenic, adipogenic and chondrogenic) and surface antigens (CD146, STRO-1, CD44, CD90, CD45, CD34) were evaluated in vitro. The cells were transplanted into the subcutaneous space of nude mice to assess capacity for ectopic bone formation at 8 weeks after implantation. Results: PDLSC, ABSC and BMSC differentiated into osteoblasts, adipocytes and chondrocytes under defined condition. The cells expressed the mesenchymal stem cell markers differently. When transplanted into athymic nude mice, these three kinds of cells with hydroxyapatite /${\beta}$- tricalcium phosphate (HA/TCP) carrier showed ectopic bone formation. Conclusions: This study demonstrated that canine dental stem cells have stemness like bone marrow stem cells. Transplantation of these cells might be used as a therapeutic approach for dental stem cell-mediated periodontal tissue regeneration.

• Food Science and Preservation
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• v.12 no.1
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• pp.8-16
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• 2005

To develop natural antimicrobial agents for extending the self-life of Kimchi, the effect of botanical antimicrobial agent-citrus products(BAAC) on microorganisms related to Kimchi spoilage was investigated. The inhibitory effect of BAAC on microorganisms related to Kimchi spoilage was increased according to the concentration of BAAC. Antimicrobial activities of BAAC against microoiganisms related to Kimchi spoilage were remarkably high. The effect of BAAC on the cellular membrane function of microorganisms showed the perturbation of cells in the presence of BAAC. Direct isualization of microbial cells by using both transmission md scanning electron microscope showed microbial cell membrane was destroyed by treating with BAAC. It could be confirmed that BAAC completely inhibit the growth of the test strains. The pH of BAAC-added Kimchi was a little higher than that of the control through the fermentation period. Titratable acidify, vitamin C and viable cells in BAAC-added Kimchi were changed more slowly than those in the control. Sensory evaluation did not show any significant difference between $0.01\%$ BAAC-added Kimchi and the control that showed the best palatabilities during fermentation.

• Korean Journal of Plant Resources
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• v.27 no.4
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• pp.279-285
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• 2014

Nutritional composition, including total phenolics, tannins and nutrient components, of acorns of Q. actissima, Q. serrata, Q. variabilis and Q. mongolica were analyzed. Acorns were collected from each tree species, which were grown in a seed orchard. Contents of both total phenolics and tannins in acorns of Q. serrata were higher than those of Q. actissima (p<0.05). Interestingly, Q. serrata contained the highest amount of water soluble tannins (71 mg/g dw) and the lowest levels of water insoluble tannins (8.1 mg/g dw) among 4 oak species, resulting that acorns of Q. serrata had the lowest proportion of insoluble tannins. Among 4 oak species tested, Q. mongolicav acorns contained the highest levels of both total dietary fiber (TDF) and ascorbic acid, while the content of beta-carotene in Q. mongolicav was 52-fold lower than that in Q. variabilis ($520{\mu}g/100g$). Our result showed that nutritional composition of acoms was significantly different between oak species, indicating that tastes or nutritional values might be different as well among major oak species in Korea.

• Restorative Dentistry and Endodontics
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• v.26 no.5
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• pp.418-435
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• 2001

Root canal preparation process is of utmost importance in successful treatment of root canal. Also, one of the most important purpose of the root canal preparation is to enlarge the root canal three dimensionally without changing the curvature of the root canal However as the curvature of the root canal increases, there are many difficulties involved in formation of optimum root canal. Therefore in order to solve the above mentioned problems, new developments in methods of root canal preparation and equipments for such purposes were made. Recently, vigorous studies about newly introduced engine-driven nickel-ti-tanium rotary file are conducted. As shown in research results to dates, it is well established that the use of nickel-titanium file is better suited for curved root canal than stainless steel file in maintaining the curvature or root canal and reducing the deformation of root canal. However it is also acknowledged that there are a few discrepancies in research results according to protocol, due to failure to remove variables in experiments. In addition, although it is recommended by the manufacturer that the GT rotary file should maintain a low rotational speed of 150~350rpm and 'light pressure' as light as not to break the lead of a pencil, academic studies about the vertical force which is not yet standardized are not sufficiently explored. Therefore, this research devised and utilized a special research equipment to standardize the appropriate range of vertical force for GT rotary file through experiments by breaking of the lead of a pencil as expressed by the manufacturer and to accurately measure factors involved through repeating and recreating the environment of root canal preparation. Forming nine experimental groups by varying the vertical forces (150g. 220g, 300g) and rpm (150rpm, 250rpm, 350rpm), the effects of changing vertical forces and rpm on working efficiency were measured in terms of time expended in root canal preparation by crown-down method using a transparent resin block with 35 degree curvature and GT rotary file (z-test). The following research using this special research equipment that involved nine experimental groups and varying the vertical force for root canal preparation from 300g which is within the normal vertical force range to 700g and 1000g which fall outside the normal rpm range. The results were as follows : 1. Analysis of the experiment results revealed that the time spent in root canal preparation decreased as the vertical forces and rpm increased (p<0.05). Also, the effects of rpm were greater than those of the vertical forces within the normal vertical force range ($\beta$-weight test). 2. Observation of the deformation of GT rotary file revealed that deformation increases in a direct correlation with the vertical force increase and in a reverse correlation with the rpm decrease. In the case of the vertical forces close to the normal range, the probability of GT rotary file deformation were quite different depending on the rpm changes. In the case of greater vertical forces, the occurrences of deformation of the file were more frequent regardless of the rpm changes. 3. Deformation and breakage of file were also commonly observed in the expended time measurement experiments and GT rotary file deformation experiments in which low speed rpm (150rpm) was used and at the curved portion of the resin block.

• Molecules and Cells
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• v.38 no.11
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• pp.966-974
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• 2015

Despite the presence of toll like receptor (TLR) expression in conventional $TCR{\alpha}{\beta}$ T cells, the direct role of TLR signaling via myeloid differentiation factor 88 (MyD88) within T lymphocytes on graft-versus-host disease (GVHD) and graft-versus-leukemia (GVL) effect after allogeneic stem cell transplantation (allo-SCT) remains unknown. In the allo-SCT model of C57BL/6 ($H-2^b$) ${\rightarrow}$ B6D2F1 ($H-2^{b/d}$), recipients received transplants of wild type (WT) T-cell-depleted (TCD) bone marrow (BM) and splenic T cells from either WT or MyD88 deficient (MyD88KO) donors. Host-type ($H-2^d$) P815 mastocytoma or L1210 leukemia cells were injected either subcutaneously or intravenously to generate a GVHD/GVL model. Allogeneic recipients of MyD88KO T cells demonstrated a greater tumor growth without attenuation of GVHD severity. Moreover, GVHD-induced GVL effect, caused by increasing the conditioning intensity was also not observed in the recipients of MyD88KO T cells. In vitro, the absence of MyD88 in T cells resulted in defective cytolytic activity to tumor targets with reduced ability to produce IFN-${\gamma}$ or granzyme B, which are known to critical for the GVL effect. However, donor T cell expansion with effector and memory T-cell differentiation were more enhanced in GVHD hosts of MyD88KO T cells. Recipients of MyD88KO T cells experienced greater expansion of Foxp3- and IL4-expressing T cells with reduced INF-${\gamma}$ producing T cells in the spleen and tumor-draining lymph nodes early after transplantation. Taken together, these results highlight a differential role for MyD88 deficiency on donor T-cells, with decreased GVL effect without attenuation of the GVHD severity after experimental allo-SCT.