• 한국약용작물학회:학술대회논문집
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• 2008.11a
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• pp.249-250
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• 2008

• Molecular & Cellular Toxicology
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• v.4 no.1
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• pp.16-21
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• 2008

Cell death of trophoblast, particularly by abnormal release of physiological nitric oxide (NO) has been known to be a causative factor of pre-eclampsia. In the present study, effects of intracellular calcium increase enhancing the activity of NO synthases (neuronal NO synthase, nNOS in this trophoblast cells) on the cell death were examined in a human placental full-term cell line (HT-1). Furthermore, we analyzed the possible mechanisms underlying the augmentation of $Ca^{++}$-mediated NOS activity mediated by protein kinases like PKC, PKA, or CaM-KII. In experiments for cell toxicity, a calcium ionophore (ionomycin $10{\mu}M$) enhanced cell death confirmed by MTT assay, and increased significantly nNOS activity determined with a hemoglobin oxidation assay. This cell death was partially protected by pre-treatment of 7-nitroindazole (7-NI, $10{\mu}M$ and $100{\mu}M$), a nNOS-specific inhibitor. Additionally, $Ca^{++}$-ionophore -induced increase of nNOS activity also was partially normalized by pre-treatment of specific inhibitors of protein kinases, PKC, PKA or CaM-KII. Therefore, we suggest that an increase of calcium influx, leading to the activation of nNOS activity, which in turn may result in the death of trophoblast cells by involvement of signaling mechanisms of protein kinases.

• The Journal of the Korean dental association
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• v.55 no.2
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• pp.156-164
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• 2017

Purpose: The aim of this in vitro study was to assess changes in remineralization by stimulated human saliva over a short period of 48 hours with quantitative light-induced fluorescence (QLF) technology. Materials and Methods: Bovine incisor surfaces were demineralized for 10 days. Two types of stimulated saliva were collected from 7 healthy persons. 24 hours after tooth brushing (Stimulated saliva group) and immediately after tooth brushing with 1,000 ppm NaF dentifrice (Dentifrice saliva group). The specimens were immersed in saliva and fluorescence images were obtained by QLF-digital (QLF-D $biluminator^{TM}$,) at 2, 4, 6, 12, 24, and 48 hours fluorescence loss (${\Delta}F%$) of the lesions. A paired t-test was performed to assess fluorescence differences between before (${\Delta}F_{baseline}$) and after (${\Delta}F_{treatment\;time}$) the remineralization process. Results: Before the remineralization, the mean ${\Delta}F_{baseline}$ of the initial demineralized specimens was $-18.42{\pm}0.15$ (%). In both groups, the ${\Delta}F$ values obtained at baseline and after 2 hours were statistically significant (P < 0.001), indicating recovery of the lesions by approximately 40% after 2 hours. After 48 hours, remineralization rates were slightly higher (49%) for the stimulated saliva group than for the dentifrice saliva group (41%), but the difference was not statistically significant. Conclusions: With QLF minute degrees of remineralization by saliva can be measured in periods as short as 2 hours. Additionally no significantly higher effects of remineralization were observed in the dentifrice saliva group when compared to the stimulated saliva group.

• Clinical and Experimental Pediatrics
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• v.49 no.5
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• pp.545-551
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• 2006

Purpose : The gene-encoding cytotoxic T lymphocyte-associated antigen-4(CTLA-4) is one of the candidate genes for conferring susceptibility to atopic dermatitis(AD). The aim of the study was to investigate the association between Korean children with AD and the polymorphisms of CTLA-4 gene promoter(-318) and exon 1(＋49). Methods : The CTLA-4 promoter(-318 T/C) and exon 1(＋49 A/G) polymorphisms were genotyped via restriction fragment length polymorphism methods in 145 children with atopic eczema, 69 children with non-atopic eczema, and 96 healthy controls. Results : There was no significant difference in genotype and allele frequencies of the CTLA-4 promoter -318 T/C and exon 1 ＋49 A/G polymorphisms when the atopic eczema, non-atopic eczema, and control groups were compared. Additionally the CTLA-4 promoter -318 T/C and exon 1 ＋49 A/G polymorphisms were not shown to be associated with severity, IgE level, or eosinophil counts. Conclusion : Our data show that the polymorphisms within the CTLA-4 promoter(-318 T/C) and exon 1(＋49 A/G) genes are not associated with susceptibility to AD in Korean children.

• The Korean Journal of Physiology and Pharmacology
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• v.20 no.3
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• pp.305-314
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• 2016

Inflammatory and fibrotic responses are accelerated during the reperfusion period, and excessive fibrosis and inflammation contribute to cardiac malfunction. NecroX compounds have been shown to protect the liver and heart from ischemia-reperfusion injury. The aim of this study was to further define the role and mechanism of action of NecroX-5 in regulating inflammation and fibrosis responses in a model of hypoxia/reoxygenation (HR). We utilized HR-treated rat hearts and lipopolysaccharide (LPS)-treated H9C2 culture cells in the presence or absence of NecroX-5 ($10{\mu}mol/L$) treatment as experimental models. Addition of NecroX-5 significantly increased decorin (Dcn) expression levels in HR-treated hearts. In contrast, expression of transforming growth factor beta 1 ($TGF{\beta}1$) and Smad2 phosphorylation (pSmad2) was strongly attenuated in NecroX-5-treated hearts. In addition, significantly increased production of tumor necrosis factor alpha ($TNF{\alpha}$), $TGF{\beta}1$, and pSmad2, and markedly decreased Dcn expression levels, were observed in LPS-stimulated H9C2 cells. Interestingly, NecroX-5 supplementation effectively attenuated the increased expression levels of $TNF{\alpha}$, $TGF{\beta}1$, and pSmad2, as well as the decreased expression of Dcn. Thus, our data demonstrate potential antiinflammatory and anti-fibrotic effects of NecroX-5 against cardiac HR injuries via modulation of the $TNF{\alpha}/Dcn/TGF{\beta}1/Smad2$ pathway.

• The Korean Journal of Physiology and Pharmacology
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• v.20 no.2
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• pp.213-220
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• 2016

Mast cells are primary mediators of allergic inflammation. Beta-1,3-glucan (BG) protects against infection and shock by activating immune cells. Activation of the BG receptor induces an increase in intracellular $Ca^{2+}$, which may induce exocytosis. However, little is known about the precise mechanisms underlying BG activation of immune cells and the possible role of mitochondria in this process. The present study examined whether BG induced mast cell degranulation, and evaluated the role of calcium transients during mast cell activation. Our investigation focused on the role of the mitochondrial calcium uniporter (MCU) in BG-induced degranulation. Black mouse (C57) bone marrow-derived mast cells were stimulated with $0.5{\mu}g/ml$ BG, $100{\mu}g/ml$ peptidoglycan (PGN), or $10{\mu}M$ A23187 (calcium ionophore), and dynamic changes in cytosolic and mitochondrial calcium and membrane potential were monitored. BG-induced mast cell degranulation occurred in a time-dependent manner, and was significantly reduced under calcium-free conditions. Ruthenium red, a mitochondrial $Ca^{2+}$ uniporter blocker, significantly reduced mast cell degranulation induced by BG, PGN, and A23187. These results suggest that the mitochondrial $Ca^{2+}$ uniporter has an important regulatory role in BG-induced mast cell degranulation.

• Proceedings of the Korean Society of Medical Physics Conference
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• 2002.09a
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• pp.457-460
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• 2002

The image quality of three-dimensional (3D) images has been widely investigated by the qualitative analysis method. A need remains for an objective and quantitative method to assess the image quality of 3D volume-rendered images. The purpose of this study was to evaluate the quantitative accuracy of distance measurements on 3D volume-rendered images of a dry human skull by using multi-detector computed tomography (MDCT). A radiologist measured five times the twenty-one direct measurement line items composed among twelve reference points on the skull surface with a digital vernier caliper. The water filled skull specimen was scanned with a MDCT according to the section thicknesses of 1.25, 2.50, 3.75, and 5.00 mm for helical (high quality; pitch 3:1) scan mode. MDCT data were reconstructed with its acquisition section thickness and with 1.25 mm section thickness for all scans. An observer also measured seven times the corresponding items on 3D volume-rendered images with measuring tools provided by volumetric analysis software. The quantitative accuracy of distance measurements on the 3D volume-rendered images was statistically evaluated (p-value < 0.05) by comparatively analyzing these measurements with the direct distance measurements. The accuracy of distance measurements on the 3D volume-rendered MDCT images acquired with 1.25, 2.50, 3,75 and 5.00 mm section thickness and reconstructed with its section thickness were 48%, 33%, 23%, and 14%, respectively. Meanwhile, there were insignificant statistical differences in accuracy of distance measurements among 3D volume-rendered images reconstructed with 1.25 mm section thickness for the each acquisition section thickness. MDCT images acquired with thick section thickness and reconstructed with thin section thickness in helical scan mode should be effectively used in medical planning of 3D volume-rendered images. The quantitative analysis of distance measurement may be a useful tool for evaluating the quantitative accuracy and the defining optimal parameters of 3D volume-rendered CT images.

• Journal of Korean Dental Science
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• v.10 no.1
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• pp.29-34
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• 2017

Purpose: The purpose of this study was to evaluate the microleakage of various types of resin-bonded fixed partial dentures (RBFPDs) after artificial aging. Materials and Methods: Forty models with missing first molar were fabricated using artificial resin teeth and were divided into four groups: Group A, conventional RBFPDs design; Group B, modified RBFPDs design; Group C, assembled 3-piece RBFPDs design; and Group D, assembled 3-piece RBFPDs with different occlusal rest positions. Half of the specimens underwent chewing simulation process (240,000 cycles, 50 N load, 1.7 Hz) and thermocycling (temperatures $5^{\circ}C{\sim}55^{\circ}C$, dwelling time 30 seconds) and the remaining 20 specimens didn't receive any treatment. All the specimens were immersed in 2% methylene blue solution for 24 hours to evaluate microleakage, and were sectioned at the middle part of abutment teeth. To evaluate the microleaskage, a dye penetration was calculated. Result: With artificial aging, cyclic loading and thermocycling, a 3-piece RBPFD and a 2-piece RBPFD using original tooth undercuts have significantly lower microleakge (P<0.05) compared to the conventional design of RBPFD and modified RBPFD. Conclusion: Within the limit of this experiment, the assembled RBFPDs exhibited a smaller microleakage than the conventional RBFPDs, implying that the assembled RBFPDs can be more effective for reducing the dislodgement of the RBFPDs.

• Biomolecules & Therapeutics
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• v.19 no.1
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• pp.38-44
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• 2011

Cisplatin is widely used for various types of cancers. However, its side effects, most notably, renal toxicity often limit its clinical utility. Although previous metabolomic studies reported possible toxicity markers, they used small number of animals and statistical approaches that may not perform best in the presence of intra-group variation. Here, we identified urinary biomarkers associated with renal toxicity induced by cisplatin using NMR-based metabolomics combined with Orthogonal Projections to Latent Structures-Discriminant Analysis (OPLS-DA). Male Sprague-Dawley rats (n=22) were treated with cisplatin (10 mg/kg single dose), and the urines obtained before and after treatment were analyzed by NMR. Multivariable analysis of NMR data presented clear separation between non-treated and treated groups. The OPLS-DA statistical results revealed that 1,3-dimethylurate, taurine, glucose, glycine and branched-chain amino acid (isoleucine, leucine and valine) were significantly elevated in the treated group and that phenylacetylglycine and sarcosine levels were decreased in the treated group. To test the robustness of the approach, we built a prediction model for the toxicity and were able to predict all the unknown samples (n=14) correctly. We believe the proposed NMR-based metabolomics with OPLS-DA approach and the resulting urine markers can be used to augment the currently available blood markers.

• Biomolecules & Therapeutics
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• v.15 no.3
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• pp.150-155
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• 2007

In the present study, we have tested the effect of dioleoyl phosphatidic acid (PA) on intracellular $Ca_{2+}$ concentration ($[Ca^{2+}]_{i}$) in two human colon cancer cell lines (HCT116 and HT29). PA and lysophosphatidic acid (LPA), a bioactive lysolipid, increased $[Ca^{2+}]_{i}$ in both HCT116 and HT29 cell lines. Increases of $[Ca^{2+}]_{i}$ by PA and LPA were more robust in HCT116 cells than in HT29 cells. A specific inhibitor of phospholipase C (U73122), however, was not inhibitory to the cell responses. Pertussis toxin, a specific inhibitor of $G_{i/o}$ type G proteins, however, had an inhibitory effect on the responses except for an LPA-induced one in HT29 cells. Ruthenium red, an inhibitor of the ryanodine receptor, was not inhibitory on the responses, however, 2-APB, a specific inhibitor of inositol 1,4,5-trisphosphate receptor, completely inhibited both lipid-induced $Ca^{2+}$ increases in both cell types. Furthermore, by using Ki16425 and VPC32183, two structurally dissimilar specific antagonists for $LPA_{1}/LPA_{3}$ receptors, an involvement of endogenous LPA receptors in the $Ca^{2+}$ responses was observed. Ki16425 completely inhibited the responses but the susceptibility to VPC32183 was different to PA and LPA in the two cell types. Expression levels of five LPA receptors in the HCT116 and HT29 cells were also assessed. Our data support the notion that PA could increase $[Ca^{2+}]_{i}$ in human colon cancer cells, probably via endogenous LPA receptors, G proteins and $IP_{3}$ receptors, thereby suggesting a role of PA as an intercellular lipid mediator.