• Journal of Pharmaceutical Investigation
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• 제37권3호
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• pp.131-135
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• 2007

A previous report recently demonstrated that ultrasound-induced hyperthermia (USHT:0.4 watts (W)/$cm^2$ at $41^{\circ}C$) could increase cellular uptake of P-glycoprotein (P-gp) substrates in P-gp expressing cancer cell lines. Since P-gp plays a major role in limiting drug permeability in the multi-drug resistant (MDR) cells, studies were conducted to elucidate the mechanism of USHT on cellular accumulation of P-gp and non-P-gp substrate in MDR cells. To accomplish this aim, we studied the effects of USHT on the accumulation of P-gp substrate, R123 and non-P-gp substrate, antipyrine in MDR cells. We demonstrated that USHT increased permeability of hydrophobic molecules (R123 and $[^{14}C]$-antipyrine). The enhanced permeability is reversible and size-dependent as USHT produces a much larger effect on cellular accumulation of $[^{14}C]$-antipyrine (MW 188) than that of R123 (MW 380.8). These results suggest that USHT could affect MDR cells more sensitive than BBMECs. Also, the present results point to the potential use of USHT to increase cellular uptake of P-gp recognized substrates, mainly anti-cancer agents into cancer cells.

• Journal of Welding and Joining
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• 제11권4호
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• pp.103-111
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• 1993

Recently, several high-tensile steels(e.g. 80kg and above, $2^{1/4}Cr$-1Mo)having good quality to high temperature and pressure-resistance are widely used to construct petroleum-plant and pressure vessel of heat or nuclear-power plant. However, in the steels, reheating crack at grain boundaries of the heat affected zone(HAZ) occures during post welding heat treatment(PWHT)to remove welding residual stress. In order to study theoretically the characteristics of reheating crack created by PWHT, the computer program of three-dimensional thermal-elasto-plasto-creep analysis based on finite element method are developed, and then the mechanical behavior(history of creep strain accumulation and stress relaxation, etc)of welded join in thick plate during PWTH is clarified by the numerical results.

• 아시안잔디학회지
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• 제21권1호
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• pp.1-7
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• 2007

미농무성 NTEP의 자료를 이용하여 한국 기후에 적합한 creeping bentgrass 품종의 특성을 평가하였다. 벤트그래스 품종들 중에서 'L-93' 품종이 전체 평균 잔디품종 평가에서 가장 우수하였다. 특히 발아세 및 여름철의 피복율이 가장 높게 나왔다. 질감의 경우엔 'Penn A-1'과 'Penn A-2'가 높게 나왔지만 겨울철 내한성이 다른 품종들에 비하여 상당히 낮게 나왔다. 대취의 축적량은 잎 밀도가 상대적으로 낮은 'Penncross'를 비롯하여 'Pennlinks', 'Crenshaw', 'L-93' 품종들은 적은 반면, 잎 밀도가 높은 'Penn A'와 'Penn G' 계통의 품종들이 많았다. 이끼의 침입에 대한 저항성 정도는 'Penn A' 계통이 높았고 'Penncross' 품종은 가장 낮게 나타났는데, 이런 경향을 보인 것은 잎의 밀도와 시각적 잔디품질, 대취 축적량, 이끼 저항성은 밀접한 관계가 있는 것으로 판단되었다. 회색 설부병에 저항성을 보인 것은 'Penn A' 계통의 품종들이었으며 브라운팻취 내병성은 'Penncross'와 'Penn A' 계통이 높았다. 피시움병에서는 'Penncross', 'Pennlinks'가 높게 나왔다. 달라 스팟의 경우 'L-93'이 가장 높게 나와서 이 병에 대한 강한 저항성을 보였으나 피시움병에 대한 내병성은 낮은 것으로 분석되었다. 따라서 각 골프코스에서는 지금까지 널리 알려진 'Penncross' 그린의 관리방식과 달리 골프코스에 식재된 bentgrass의 품종에 잔디관리 방식을 적용하여야 할 것으로 판단된다.

• 한국균학회소식:학술대회논문집
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• 한국균학회 2015년도 추계학술대회 및 정기총회
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• pp.26-26
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• 2015

Phytophthora infestans is the causal agent of potato and tomato late blight, one of the most devastating plant diseases. P. infestans secretes effector proteins that are both modulators and targets of host plant immunity. Among these are the so-called RXLR effectors that function inside plant cells and are characterized by a conserved motif following the N-terminal signal peptide. In contrast, the effector activity is encoded by the C terminal region that follows the RXLR domain. Recently, I performed in planta functional profiling of different RXLR effector alleles. These genes were amplified from a variety of P. infestans isolates and cloned into a Potato virus X (PVX) vector for transient in planta expression. I assayed for R-gene specific induction of hypersensitive cell death. The findings included the discovery of new effector with avirulence activity towards the Solanum bulbocastanum Rpi-blb2 resistance gene. The Rpi-blb2 encodes a protein with a putative CC-NBS-LRR (a coiled-coil-nucleotide binding site and leucine-rich repeat) motif that confers Phytophthora late blight disease resistance. We examined the components required for Rpi-blb2-mediated resistance to P. infestans in Nicotiana benthamiana. Virus-induced gene silencing was used to repress candidate genes in N. benthamiana and to assay against P. infestans infections. NbSGT1 was required for disease resistance to P. infestans and hypersensitive responses (HRs) triggered by co-expression of AVRblb2 and Rpi-blb2 in N. benthamiana. RAR1 and HSP90 did not affect disease resistance or HRs in Rpi-blb2-transgenic plants. To elucidate the role of salicylic acid (SA) in Rpi-blb2-mediated resistance, we analyzed the response of NahG-transgenic plants following P. infestans infection. The increased susceptibility of Rpi-blb2-transgenic plants in the NahG background correlated with reduced SA and SA glucoside levels. Furthermore, Rpi-blb2-mediated HR cell death was associated with $H_2O_2$, but not SA, accumulation. SA affects basal defense and Rpi-blb2-mediated resistance against P. infestans. These findings provide evidence about the roles of SGT1 and SA signaling in Rpi-blb2-mediated resistance against P. infestans.

• Archives of Pharmacal Research
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• 제18권3호
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• pp.173-178
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• 1995

Ciprofloxacin resistance mechanisms were studied by investigating the inhibitory effect of ciprofloxacin on the gyrase-mediated DNA supercoiling and the intracellular accumulation of ciprofloxacin in clinical isolates of Pseudomonas aeruginosa. A higher amount of ciprofloxacin was required to inhibit the gyrases purified from the ciprofloxacin-resistant strains than that from the sensitive strain. Reconstitution of heterologous gyrase subunits from different strains revealed alterations in the A and/or the B subunits of gyrase in these strains. In addition, the resistant strains accumulated approximately a half amount of ciprofloxacin inside the cells, compared to the sensitive strain. However, when the active efflux was blocked by carbonyl cyanide m-chlorophenyl hydrazone treatment, intracellular concentration of ciprofloxacin was elevated about 4-7 fold in these strains, while the sensitive strain was not significantly affected by this treatment, indicating that the ciprofloxacin-resistant strains developed a drug efflux system. Interestingly, these resistant strains expressed an envelope protein of approximately 51 kD. These studies suggest that alterations in the gyrase as well as the active drug-efflux system conferred dual ciprofloxacin resistance mechanisms to these clinical isolates of P. aeruginosa.

• 대한의생명과학회지
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• 제25권3호
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• pp.256-266
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• 2019

In this study, obese adults were compared for their ability to predict obesity and lipid related variables and their optimal cutoff values to predict metabolic syndrome and insulin resistance. In this study, 9,256 adults aged 20 years or older and less than 80 years old, who were in the Gyeonggi region from January 2014 to December 2016 and who were examined at a general hospital, were enrolled. The diagnostic criteria for obesity were WHO (World Health Organization), and BMI $25kg/m^2$ or more presented in the Asia-Pacific region. Metabolic syndrome was diagnosed based on the criteria of American Heart Association / National Heart, Lung, and Blood Institute (AHA / NHLBI). According to the results of receiver operating characteristic curve (ROC) analysis, Triglyceride / HDL-cholesterol (TG / HDL-C), Triglyceride and Glucose (TyG) index, lipid accumulation product (LAP) and visceral adiposity index (VAI) showed high predictive power for diagnosing metabolic syndrome. The diagnostic accuracy of LAP (AUC: 0.854) for males and VAI (0.888) for females was the highest. The optimal cutoff value of LAP was 42.71 for male and 35.44 for female, and the cutoff value of VAI was 1.92 for male and 2.15 for female. In addition, WHtR (waist to height ratio), TyG index, and LAP were used as predictors of insulin resistance in obese adults. Therefore, LAP and VAI were superior to other indicators in predicting metabolic syndrome in obese adults.

• 대한한방내과학회지
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• 제35권4호
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• pp.428-438
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• 2014

Objectives: Obesity is an important cause of insulin resistance that leads to obese type 2 diabetes. Recently it has been found that obesity is associated with adipose tissue accumulation which causes systemic inflammation. In this study, we investigated effects of Inula helenium on the inflammation in high fat diet-induced insulin resistance mouse. Methods: Insulin resistance was induced in C57BL/6 male mice (19~21 g) on a 60% fat diet. Mice were divided into 3 groups (n=6) of normal, control and Inula helenium. After 12 weeks, body weight, FBS, oral glucose tolerance test (OGTT), serum level of insulin, epididymal fat pad, liver weight and the gene expression of tumor necrosis factor (TNF)-${\alpha}$, interleukin (IL)-6, interleukin (IL)-10 and cluster of differentiation (CD) 68 were measured. Also, adipose tissue macrophage was analyzed by fluorescence activated cell sorting. Results: Inula helenium significantly reduces oral glucose tolerance levels, insulin serum level and adipose tissue macrophage. Also Inula helenium increased IL-10 gene expression and decreased CD68 gene expression. Conclusions: These results show that Inula helenium has anti-insulin resistance and anti-inflammatory effects on a high fat diet-induced insulin resistance mouse model.

• 한국토양비료학회지
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• 제45권4호
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• pp.572-581
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• 2012

In this study, we compared growth pattern, floc yield, Exo-polysaccharides (EPS) production, Poly-${\beta}$-hydroxybutyrate (PHB) accumulation, resistance to osmotic and acid stress in Methylobacterium strains CBMB20, CBMB27, CBMB35, and CBMB110. Modified high C:N ratio medium denoted as HCN-AMS medium was used with a C:N ratio of 30:1. The HCN-AMS medium favored increased growth in all the studied strains. All Methylobacterium strains tested positive for EPS production and showed positive fluorescence with calcoflour stain. Elevated levels of EPS production from 4.2 to 75.0% was observed in HCN-AMS medium. Accumulation of PHB in HCN-AMS medium increased by 3.8, 36.7, and 12.0% in strains CBMB27, CBMB35, and CBMB110 respectively. Among the abiotic stresses, osmotic stress-induced growth inhibition of Methylobacterium strains was found to be lowered when grown in HCN-AMS medium. Likewise, growth inhibition due to acid stress at pH 5.0 was lower for strains grown in HCN-AMS medium compared to growth in AMS medium. Enhanced survivability under stress conditions may be attributed to the high EPS and PHB production at increased carbon concentration in the growth medium.

• Archives of Pharmacal Research
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• 제28권7호
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• pp.823-828
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• 2005

Multidrug resistance (MDR) is one of the most significant obstacles in cancer chemotherapy. One of the mechanisms involved in the development of MDR is the over-expression of P-glycoprotein (P-gp). It is widely known that natural compounds found in vegetables, fruits, plant-derived beverages and herbal dietary supplements not only have anticancer properties, but may also modulate P-gp activity. Therefore, the purpose of this investigation was to examine the effects of naturally occurring products on P-gp function in human breast cancer cell lines, MCF-7 (sensitive) and MCF-7/ADR (resistant). The accumulation of daunomycin (DNM), a P-gp substrate, was greater in the sensitive cells compared to the resistant cells, while the efflux of DNM was higher in the resistant cells compared to the sensitive cells over a period of 2h. The $IC_{50}$ value of DNM in the resistant cells was about 22 times higher than that in the sensitive cells, indicating an over-expression of P-gp in the resistant cells, MCF-7/ADR. All of the compounds tested, with the exception of fisetin, significantly decreased the $IC_{50}$ value of DNM. Biochanin A showed the greatest increase in $[^3H]-DNM$ accumulation, increasing by $454.3{\pm}19.5%$ in the resistant cells, whereas verapamil, the positive control, increased the accumulation by $229.4{\pm}17.6%$. Also, the accumulation of $[^3H]-DNM$ was increased substantially by quercetin and silymarin while it was reduced by fisetin. Moreover, biochanin A, silymarin, and naringenin significantly decreased DNM efflux from MCF-7/ADR cells compared with the control. These results suggest that some flavonoids such as biochanin A and silymarin may reverse MDR by inhibiting the P-gp function.

• The Plant Pathology Journal
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• 제35권4호
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• pp.313-320
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• 2019

Rye was used here to dissect molecular mechanisms of resistance to Fusarium head blight (FHB) and to go deeper with our understanding of that process in cereals. F. culmorum-damaged kernels of two lines different in their potential of resistance to FHB were analyzed using two-dimensional gel electrophoresis and mass spectrometry to identify resistance markers. The proteome profiling was accompanied by measurements of ${\alpha}-$ and ${\beta}-amylase$ activities and mycotoxin content. The proteomic studies indicated a total of 18 spots with clear differences in protein abundance between the more resistant and more susceptible rye lines after infection. Eight proteins were involved in carbohydrate metabolism of which six proteins showed a significantly higher abundance in the resistant line. The other proteins recognized here were involved in stress response and redox homeostasis. Three remaining proteins were associated with protease inhibition/resistance and lignin biosynthesis, revealing higher accumulation levels in the susceptible rye line. After inoculation, the activities of ${\alpha}-$ and ${\beta}-amylases$, higher in the susceptible line, were probably responsible for a higher level of starch decomposition after infection and a higher susceptibility to FHB. The presented results could be a good reference for further research to improve crop resistance to FHB.