• Restorative Dentistry and Endodontics
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• v.25 no.4
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• pp.499-508
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• 2000

The purposes of this study were to evaluate the validity of 2 kinds of digital radiography techniques in evaluating the radiopacity comparison of restorative materials and to determine the relative radiopacities of several kinds of compomer and flow able resin using these techniques. After taking radiographs of an aluminum step wedge, con-elation of optical density calibration curves were evaluated between conventional radiography with transmission densitometer and CD-Dent digital radiography (storage phosphor system) and between conventional one and RVG$^{(R)}$ digital radiography (CCD system). Compomers such as Dyract$^{(R)}$ AP, Compoglass$^{(R)}$, and Dyract flow$^{(R)}$, and flowable resins such as Ultraseal-XT$^{(R)}$ plus$^{TM}$, Revolution$^{TM}$, Aeliteflo$^{TM}$ and Tetric-flow$^{(R)}$ were used. Five specimens of 5mm in diameter and 2 mm thick were fabricated with each material. Radiopacities of the materials were measured using the above radiographic techniques and compared. The results were as follows: 1. When the optical density calibration curves were compared, conventional radiography and both CD-Dent and RVG$^{(R)}$ digital radiographies showed very high inverse correlations (${\gamma}$=-0.95, ${\gamma}$=-0.98 ; p<0.05). 2. All the tested restorative materials showed levels of radiopacity the same as or greater than that of dentin (p<0.05), Radiopacities of Dyract$^{(R)}$ AP, Compoglass$^{(R)}$, and Tetric flow$^{(R)}$ were greater than those of Revolution$^{TM}$, Aeliteflo$^{TM}$, or dentin (p<0.05). 3. Radiopacities of Dyract$^{(R)}$ AP, Compoglass$^{(R)}$, and Tetric flow$^{(R)}$ were shown to be greater than that of enamel when conventional radiography and CD-Dent digital radiography were used (p<0.05). Radiopacity of Dyract flow$^{(R)}$ was shown to be greater than that of Enamel when conventional radiography was used (p<0.05).

• The Korean Journal of Nuclear Medicine Technology
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• v.27 no.2
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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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• v.17 no.2
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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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• v.40 no.2
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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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• v.15 no.5
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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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• v.40 no.10
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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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• v.25 no.6
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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.

• The Journal of Korean Medicine Ophthalmology and Otolaryngology and Dermatology
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• v.25 no.1
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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.

• Microbiology and Biotechnology Letters
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• v.45 no.1
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• pp.27-34
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• 2017

$C/EBP{\beta}$ and $C/EBP{\delta}$ are required for the initiation of adipogenesis and induce the expression of key adipogenic regulators, such as $PPAR{\gamma}$ and $C/EBP{\alpha}$. In the present study, we have examined the effects of silibinin and its possible molecular mechanisms in regulating adipocyte differentiation and expression of $C/EBP{\beta}$ and $C/EBP{\delta}$ in the early stage of adipogenesis. Silibinin statistically significantly inhibits intracellular lipid accumulation and the mRNA expression of various genes involved at different stages during adipogenesis. Silibinin also suppresses expression of lipoprotein lipase (LPL), fatty acid binding protein 4 (AP2), and adiponectin in 3T3-L1 adipocytes. Thus, the anti-adipogenic effect of silibinin seems to originate from the ability to inhibit the expression of $C/EBP{\beta}$ and $C/EBP{\delta}$. Furthermore, silibinin decreases cell viability for differentiation period and induces apoptotic cell death through capspase-3 activation.

• Korean Journal of Food Science and Technology
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• v.22 no.5
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• pp.533-538
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• 1990

In polysaccharide fermentation with Aureobasidium pullulans, the aeration effects on the production of polysaccharide and the rheological properties of fermentation broth were studied. The increase of the aeration rates from 0.5 to 2.0vvm at 500 rpm yielded the maximum specific production rate of polysaccharide from 0.046 to $0.093 (hr^{-1})$, and the maximum specific growth rate of cells from 0.168 to $0.192 (hr^{-1})$. The viscosity behavior of fermentation broths at the different aeration rates followed the power-law ${\tau}= K({\gamma})^n$. The viscosity attributed by cells was about 10% of the total viscosity of fermentation broth and most of viscosity was attributed by the polysaccharide produced. The relationship between power-law parameters and the concentration of polysaccharide generally satisfied the etㄴrations with the regression coefficient greater than 0.980, $lnK(t)= ln({\tau})_o-n(t)\;ln({\gamma})_o\;and\;K(t)=A P(t)^B$.