• Restorative Dentistry and Endodontics
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• 제25권4호
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• pp.499-508
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• 2000

본 연구에서는 이종의 디지털 방사선사진술이 수복물의 방사선불투과성 비교에 적절하게 이용될 수 있는지의 여부를 평가하고, 이 기법을 이용하여 수종의 compomer 및 유동성 레진의 방사선불투과도를 측정, 비교하고자 하였다. Aluminum step wedge를 방사선사진촬영 하여 기 존의 transmission densitometer와 CD-Dent (phosphor scanning system) 및 RVG$^{(R)}$ (CCD system) 등 두 종류의 디지털 방사선사진술과의 광학밀도 상관관계를 평가하였고, 두께 2mm, 지름 5mm인 원형의 금속주형을 이용하여 Dyract$^{(R)}$ AP, Compoglass$^{(R)}$ 및 Dyract flow$^{(R)}$ 등 3종의 compomer와 Ultraseal-XT$^{(R)}$ plus$^{TM}$, Revolution$^{TM}$, Aeliteflo$^{TM}$ 및 Tetric-flow$^{(R)}$ 등 4종의 유동성 레진의 시편을 각각 5개씩 제작후 방사선불투과성을 측정하고 비교, 평가하여 다음과 같은 결과를 얻었다. 1. Aluminum step wedge를 사용한 광학밀도 측정곡선을 비교한 바, 통상적인 방사선사진술로 얻은 필름의 상에서 transmission densitometer로 방사선불투과도를 측정 한 곡선과 CD-Dent 및 RVG$^{(R)}$ 등 디지털 방사선사진술로 얻은 상에서 CADIA로 불투과도를 측정한 곡선들 사이에서 각각 매우 높은 역상관관계가 나타났다(${\gamma}$=-0.95, ${\gamma}$=-0.98 ; p<0.05). 2. 모든 수복채 공히 상아질과 유사하거나 높은 방사선불투과도를 나타내었고 (p<0.05), compomer인 Dyract$^{(R)}$ AP와 Compoglass$^{(R)}$, 그리고 유동성 레진인 Tetric-flow$^{(R)}$는 통상적인 방사선사진술 및 2종의 디지털 방사선사진술에서 공히 유동성 레진인 Revolution$^{TM}$과 Aeliteflo$^{TM}$, 그리고 상아질에 비해 유의하게 높은 방사선불투과도를 나타내었다 (p<0.05). 3. Compomer인 Dyract$^{(R)}$ AP와 Compoglass$^{(R)}$, 그리고 유동성 레진인 Tetric-flow$^{(R)}$는 통상적인 방사선사진술 및 CD-Dent 디지털 방사선사진술에서 공히 법랑질에 비해 높은 방사선불투과도를 나타내었고(p<0.05), compomer인 Dyract flow$^{(R)}$는 통상적인 방사선사진술에서만 법랑질에 비해 높은 방사선불투과도를 나타내었다(p<0.05).

• 핵의학기술
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• 제27권2호
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• pp.129-132
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• 2023

Purpose: Positron emisson tomography (PET) is a crucial medical imaging scanner for the detection of cancer lesions. In order to maintain the improved image quality, it is crucial to apply detectors of superior performance. Therefore, the purpose of this study was to compare PET image quality using Monte Carlo simulation based on the detector materials of BGO, LSO, and LuAP. Materials and Methods: The Geant4 Application for Tomographic Emission (GATE) was used to design the PET detector. Scintillations with BGO, LSO and LuAP were modelled, with a size of 3.95 × 5.3 mm2 (width × height) and 25.0 mm (thickness). The PET detector consisted of 34 blocks per ring and a total of 4 rings. A line source of 1 MBq was modelled and acquired with a radius of 1 mm and length of 20 mm for 20 seconds. The acquired image was reconstructed maximum likelihood expectation maximization with 2 iteration and 10 subsets. The count comparison was carried out. Results and Discussion: The highest true, random, and scatter counts were obtained from the BGO scintillation detector compared to LSO and LuAP. Conclusion: The BGO scintillation detector material indicated excellent performance in terms of detection of gamma rays from emitted PET phantom.

• Journal of Microbiology and Biotechnology
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• 제17권2호
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• pp.348-358
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• 2007

Metallothionein, a cysteine-rich stress response protein that is naturally induced by a variety of immunologic stressors, has been shown to suppress autoimmune disorders through mechanisms not yet fully defined. In the present study, we examined the underlying mechanisms by which metallothionein might mediate such regulation of autoimmunity. $Na\ddot{i}ve\;CD4^+$ T cells from metallothionein-deficient mice differentiated to produce significantly less IL-10, $TGF-{\gamma}$, and repressor of GATA, but more $IFN-{\gamma}$ and T-bet, when compared with those from wild-type mice. The levels of IL-4 and GATA-3 production were not different between the two groups of mice. Conversely, treatment with exogenous metallothionein during the priming phase drove $na\ddot{i}ve$ wild-type $CD4^+\;T$ cells to differentiate into cells producing more IL-10 and $TGF-{\beta}$, but less $IFN-{\gamma}$ than untreated cells. Metallothionein-primed cells were hyporesponsive to restimulation, and suppressive to T cell proliferation in an IL-10-dependent manner. Lymphocytes from metallothionein-deficient mice displayed significantly elevated levels of AP-1 and JNK activities in response to stimulation compared with those from wild-type controls. Importantly, transgenic mice overexpressing metallothionein exhibited significantly reduced susceptibility to collagen-induced arthritis and enhanced IL-10 level in the serum, relative to their nontransgenic littermates. Taken together, these data suggest that metallothionein is able to promote the generation of IL-10-and $TGF-{\beta}$-producing type 1 regulatory T-like cells by downregulating JNK-dependent AP-1 activity. Thus, metallothionein may play an important role in the regulation of Th1-dependent autoimmune arthritis, and may represent both a potential target for therapeutic manipulation and a critical element in the diagnostic assessment of disease potential.

• Reproductive and Developmental Biology
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• 제40권2호
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• pp.23-26
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• 2016

Transcription factor called activating enhancer binding protein 2C (AP2-gamma) is found in a variety of species and expressed from oocyte stage onwards, particularly restricted to the trophectoderm. Recent studies demonstrated that ablation of Tfap2c led to failure of tight junction biogenesis, particularly the knock-down embryos of Tfap2c did not form cavity from morula to blastocyst in mouse and pig. We speculated that the Tfa2pc may also be involved in desmosome biogenesis because blastocoel formation is coincident with the establishment of desmosome. To determine this, we depleted Tfap2c injecting siRNA into one-cell zygote and analysed the expression levels of genes that are required for desmosome complex such as PkP2, Pkp3, Dsc2, and Dsg2. We found only Pkp3 was up-regulated in the knockdowned morula embryos. Interestingly, upstream region of Pkp3 had putative Tfap2c binding sites. In conclusion, our results suggest that Tfap2c is not a crucial factor but somehow it might be involved in desmosome biogenesis directly or indirectly via Pkp3.

• The Korean Journal of Physiology and Pharmacology
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• 제15권5호
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• pp.251-258
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• 2011

Here we have investigated how lactosylceramide (LacCer) modulates gene expression of adhesion molecules in TNF-${\alpha}$ and IFN ${\gamma}$ (CM)-stimulated astrocytes. We have observed that stimulation of astrocytes with CM increased the gene expression of ICAM-1 and VCAM-1. D-Threo-1-phenyl-2-decanoylamino-3-morpholino-1-propanol (PDMP) and N-butyldeoxynojirimycin (NBDNJ), inhibitors of glucosylceramide synthase (GLS) and LacCer synthase (galactosyltransferase, GalT-2), inhibited the gene expression of ICAM-1 and VCAM-1 and activation of their gene promoter induced by CM, which were reversed by exogenously supplied LacCer. Silencing of GalT-2 gene using its antisense oligonucleotides also attenuated CM-induced ICAM-1 and VCAM-1 expression, which were reversed by LacCer. PDMP treatment and silencing of GalT-2 gene significantly reduced CM-induced luciferase activities in NF-${\kappa}B$, AP-1, GAS, and STAT-3 luciferase vectors-transfected cells. In addition, LacCer reversed the inhibition of NF-${\kappa}B$ and STAT-1 luciferase activities by PDMP. Taken together, our results suggest that LacCer may play a crucial role in the expression of ICAM-1 and VCAM-1 via modulating transcription factors, such as NF-${\kappa}B$, AP-1, STAT-1, and STAT-3 in CM-stimulated astrocytes.

• Molecules and Cells
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• 제40권10호
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• pp.706-713
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• 2017

Osteoclasts are bone-resorbing cells that are derived from hematopoietic precursor cells and require macrophage-colony stimulating factor and receptor activator of nuclear factor-${\kappa}B$ ligand (RANKL) for their survival, proliferation, differentiation, and activation. The binding of RANKL to its receptor RANK triggers osteoclast precursors to differentiate into osteoclasts. This process depends on RANKL-RANK signaling, which is temporally regulated by various adaptor proteins and kinases. Here we summarize the current understanding of the mechanisms that regulate RANK signaling during osteoclastogenesis. In the early stage, RANK signaling is mediated by recruiting adaptor molecules such as tumor necrosis factor receptorassociated factor 6 (TRAF6), which leads to the activation of mitogen-activated protein kinases (MAPKs), and the transcription factors nuclear factor-${\kappa}B$ (NF-${\kappa}B$) and activator protein-1 (AP-1). Activated NF-${\kappa}B$ induces the nuclear factor of activated T-cells cytoplasmic 1 (NFATc1), which is the key osteoclastogenesis regulator. In the intermediate stage of signaling, the co-stimulatory signal induces $Ca^{2+}$ oscillation via activated phospholipase $C{\gamma}2$ ($PLC{\gamma}2$) together with c-Fos/AP-1, wherein $Ca^{2+}$ signaling facilitates the robust production of NFATc1. In the late stage of osteoclastogenesis, NFATc1 translocates into the nucleus where it induces numerous osteoclast-specific target genes that are responsible for cell fusion and function.

• Archives of Pharmacal Research
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• 제25권6호
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• pp.747-758
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• 2002

The skin displays a highly active metabolism of polyunsaturated fatty acids (PUFA). Dietary deficiency of linoleic acid (LA), an 18-carbon (n-6) PUFA, results in characteristic scaly skin disorder and excessive epidermal water loss. Although arachidonic acid (AA), a 20-carbon (n6) PUFA, is metabolized via cyclooxygenase pathway into predominantly prostaglandin $E_2(PGE_2)$ and $PGF_{2{\alpha}}$, the metabolism of AA via the 15-lipoxygenase (15-LOX) pathway, which is very active in skin epidermis and catalyzes the transformation of M into predominantly 15S-hydroxyeicosatetraenoic acid (15S-HETE). Additionally, the 15-LOX also metabolizes the 18-carbon LA into 13S-hydroxyoctadecadienoic acid (13S-HODE), respectively. Interestingly, 15-LOX catalyzes the transformation of $dihomo-{\gamma}-linolenic$ acid (DGLA), derived from dietary gamma-linolenic acid, to 15S-hydroxyeicosatrienoic acid (15S-HETrE). These monohydroxy fatty acids are incorporated into the membrane inositol phospholipids which undergo hydrolytic cleavage to yield substituted-diacylglycerols such as 13S-HODE-DAG from 13S-HODE and 15S-HETrE-DAG from 15S-HETrE. These substituted-monohydroxy fatty acids seemingly exert anti-inflammatory/antiproliferative effects via the modulation of selective protein kinase C as well as on the upstream/down-stream nuclear MAP-kinase/AP-1/apoptotic signaling events.

• 한방안이비인후피부과학회지
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• 제25권1호
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• pp.33-54
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• 2012

Objective : This study was carried out to compare Saengmaeksan-gamibang(SG) to Saengmaeksan(SM) on the efficacy of moisturization, skin whitening, anti-inflammation, and anti-allergy in atopic dematitis using NC/Nga mice model. Methods : We assessed the effects of SG and SM on tyrosinase, filaggrin, serine-palmitoyl transferase(SPT), COX-2, AP-1 in vitro, on IgE, IL-4, IL-5, IL-6, IgM, IgG1, IFN-${\gamma}$ in vivo with NC/Nga mice. Results : 1. SG increased the tyrosinase inhibition activity and the levels of filaggrin and SPT, decreasing the level of COX-2. 2. On the other hand, SM decreased the tyrosinase inhibition activity and the levels of filaggrin and SPT, increasing the level of COX-2. 3. Serum IgE, IL-4, 5, 6, IgM, and IgG1 were decreased in both SG group and SM group compared to the control group. The decrease degree in these factors was higher in SG than in SM. 4. Serum IFN-${\gamma}$ was increased in both SG group and SM group compared to the control group. The increase degree in IFN-${\gamma}$ was higher in SG than in SM. Conclusion : As the result of the above experiments, it was proved that SG has the moisturization, skin whitening, anti-inflammation, and anti-allergy effects, which are greater than those of SM, and provides the significant efficacy on atopic dermatitis treatment.

• 한국미생물·생명공학회지
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• 제45권1호
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• pp.27-34
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• 2017

CCAAT/enhancer-binding protein beta, delta ($C/EBP{\beta}$, ${\delta}$)는 지방세포분화 과정의 초기에 필수적으로 요구되며 지방생성 주요 조절인자인 proliferator-activated receptor gamma ($PPAR{\gamma}$) and CCAAT/enhancer-binding protein-alpha ($C/EBP{\alpha}$)의 발현을 유도한다. 본 연구에서는 silibinin의 지방세포 분화 억제 효과 및 이러한 효과가 지방세포 분화초기에 $C/EBP{\beta}$ 및 $C/EBP{\delta}$의 발현 조절을 통해 일어난 다는 것을 확인하였다. Silibinin은 지방세포 내 지질축적을 억제하고 세포분화 과정 동안 관여하는 다양한 유전자의 mRNA 발현을 억제하였다. 또한 lipoprotein lipase (LPL), fatty acid binding protein 4 (AP2) 및 adiponectin과 같은 지방세포 분화 관련 유전자의 발현을 억제시켰다. 따라서, Silibinin의 지방세포 분화 억제효과는 $C/EBP{\beta}$ 및 $C/EBP{\delta}$의 발현억제에 의한 것으로 보인다. 더불어, Silibinin은 capspase-3 활성을 통해 분화하는 세포에 특이적으로 세포사멸을 유도하는 것을 확인하였다.

• 한국식품과학회지
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• 제22권5호
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• pp.533-538
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• 1990

풀루란 발효에서 500rpm에서 통기속도를 0.5vvm, 1.0vvm, 2.0vvm으로 증가시켰을 때 최대 비성장속도는 $0.168(hr^{-1})$에서 $0.192({hr^{-1})$로 증가되었으며 풀루란의 최대 비생산속도는 $0.046({hr^{-1})$에서 $0.093({hr^{-1})$으로 증가되었다. 풀루란 발효액의 물성은 power-law를 따르는 Pseudoplasticity를 나타냈으며 Power-law 변수들과 풀루란 농도 사이에는 $lnK(t)=ln({\tau})_o-n(t)\;ln({\gamma})_o$와 $K(t)=AP(t)^B$의 상관관계를 보였다.