• 대한약리학회지
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• 제31권1호
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• pp.115-122
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• 1995

C5a 또는 PMA에 의하여 활성화된 호중구에서의 superoxide와 HOCl 생성에 나타내는 staurosporine, genistein과 pertussis toxin의 효과를 관찰하였다. C5a에 의한 superoxide과 $H_2O_2$의 생성은 staurosporine, genistein과 pertussis toxin에 의하여 억제되었다. PMA의 자극효과는 staurosporine에 의하여 억제되었으나 pertussis toxin에 의하여 영향을 받지 않았으며, 한편 이는 genistein에 의하여 더 촉진되었다. Staurosporine, genistein은 sodium fluoride에 의한 superoxide 생성을 억제 하였으나 pertussis toxin은 영향을 나타내지 않았다. PMA에 의한 $H_2O_2$의 생성은 staurosporine에 의하여 억제되었으나 pertussis toxin은 영향을 나타내지 않았다. Genistein은 PMA에 의한 $H_2O_2$의 생성에 자극효과를 나타내지 않았다. Staurosporine과 pertussis toxin은 C5a 또는 PMA에 의한 HOCl 생성을 억제하였으나, 이에 반하여 genistein은 자극하였다. C5a와 PMA에 의한 myeloperoxidase 유리는 genistein에 의하여 억제되었나, pertussis toxin의 효과는 나타나지 않았다. Staurosporine은 유리에 대한 PMA의 자극효과에 영향을 주지 않았다. Myeloperoxidase 활성은 genistein에 의하여 현저하게 증가되었으나 staurosporine과 pertussis toxin의 영향은 받지 않았다. 이상의 결과는 호중구의 respiratory burst가 protein kinase C와 protein tyrosine kinase에 의하여 조절된다고 제시한다. Protein kinase C의 직접적인 자극에 따른 superoxide 생성은 protein tyrosine kinase의 영향을 역으로 받을 것으로 추정된다. Genistein은 아마도 myeloperoxidase를 활성화하여 HOCl 생성을 촉진할 것으로 시사된다.

• 대한임상독성학회지
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• 제13권2호
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• pp.78-86
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• 2015

Purpose: The purpose of this study is to understand what kinds of chemical substances have been used annually and to investigate incidents that occurred due to chemical hazard release and to analyze statistically clinically chemical injury patients who visited one regional emergency medical center in Gumi city with documented references review. Methods: Annual chemical waste emission quantity (Kg/Year) (Cwep) was reproduced using national web site data governed by the Ministry of Environment and 5 years (from 1 .Jan. 2010 to 31. Dec. 2014) of medical records of chemical injury patients who visited our emergency department were reviewed retrospectively. By applying exclusion criteria, 446 patients of 460 patients were selected. Results: Dichloromethane, Toluene, Trichloroethylene, and Xylene were always included within Top 5 of Cweq. Six cases of chemical incidents were reported and in 3 of 6 cases involving Hydrogen fluoride were included during the study period. Male gender and twenties were the most prevalent group. Injury evoking chemicals were Hydrogen fluoride, unknown, complex chemicals (over 2 substances) in sequence. The most frequent site of wounds and injuries was the respiratory tract. Gas among status, intoxication among diagnosis, and discharge among disposition was most numerous in each group. Conclusion: There have been no uniform clinical protocols for chemical wounds and injuries due to various kinds of chemicophysical properties and ignorance of antidotes. Therefore conduct of a multicenter cohort study and experiments for ruling out chemicals according to chemicophysical priority as well as development of antidotes and clinical protocols for chemical injury patients is needed.

• Korean Chemical Engineering Research
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• 제55권1호
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• pp.48-53
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• 2017

유독물 취급업체수가 증가하고 취급업체들이 다루는 물질의 종류가 다양해지고, 그 양도 증가함에 따라 국내 화학 사업장 사고의 심각성을 보여준 대표적인 사례로 2012년 구미 불산 사고를 들 수 있다. 화학사고 발생 시 화학물질 특성과 주변 환경에 따라 효과적으로 대응책을 마련하기 위해서는 예측모델의 활용이 반드시 필요하다. 현재 존재하는 다양한 예측모델들은 실험을 통해 그 정확도를 검증된 적은 있지만, 예측모델들간의 계산 결과 비교를 통해 어떠한 경우에 어떤 모델이 가장 적합한지에 대한 활용성 부분이 부족한 실정이다. 본 연구에서는 구미 불산 사고를 사례연구로 선정하고 불화수소의 누출과 확산에 가장 정확하다고 알려진 HGSYSTEM을 이용하여 농도를 계산하였다. ERPG-2 기준농도 기준으로 사고 지점으로 부터 1 km 이상 확산됨을 확인하였다. 이 결과를 바탕으로 ALOHA와 CARIS의 결과를 비교하여, 가장 대표적인 예측 모델들의 활용성을 분석하였다.

• Restorative Dentistry and Endodontics
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• 제26권1호
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• pp.1-8
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• 2001

Dental Caries which has high prevalence rate, accounts for majority of dental diseases. Many treatment and preventive treatment has been developed, thereby reducing the prevalence rate, but in our country, fluoridization has not spread widely yet, so prevention has not been done satisfactorily. When dental caries progresses, irreversible damage of tooth structure occurs. In initial dental caries, demineralizing tooth structure can be remineralized, so restorative treatment is unnecessary. In this study, 20 teeth restored with composite resin without fluoride release were used and divided into two groups. Incipient dental caries were artificially made and demineralization procedure was done for 1 and 2 weeks, for each group. Changes in mineral contents around the margins were analysed with confocal laser scanning microscope. The results were as follow. 1. Both total fluorescence of the lesion and average fluorescence of the lesion of remineralized samples decreased compared to demineralizing state. (p＜0.01) 2. Confocal laser scanning microscopy can be used in quantitative analysis of mineral change. In result, confocal laser scanning microscopy can be used in quantitative analysis of mineral change and it could be used in many different fields of dentistry in the future.

• The Korean Journal of Physiology
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• 제24권2호
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• pp.353-362
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• 1990

Fluoride (F-), a known stimulator of G-protein, induced strong contraction in rabbit trachealis muscle. $AlCl_3\;(5{\sim}20\;{\mu}M)$, which is required for G-protein stimulation by $F^-$, potentiated the contractile response to $F^-$. $Ca^{2+}-removal$ and verapamil, a calcium channel blocker, inhibited the fluoroaluminate-induced contraction. Fluoroaluminate increased $^{45}Ca$ influx in the absence and presence of verapamil. In heparin-loaded muscle high $K^+-induced$ contraction was not affected, but acetylcholine and fluoroaluminate-induced contractions were inhibited. The fluoroaluminate-induced contraction was partially relaxed by isoproterenol, a stimulator of adenylate cyclase. Pertussis toxin partially inhibited fluoroaluminate-induced contraction and potentiated isoproterenol-induced relaxation in the presence of fluoroaluminate, but had no effect on acetylcholine-induced contraction and the isoproterenol-induced relaxation in the presence of acetylcholine. These results suggest that fluoroaluminate has the ability to stimulate at least two putative G-proteins in rabbit trachealis muscle; One causes $Ca^{2+}$ influx through the potential-operated $Ca^{2+}$ channel and the other induces intracellular $Ca^{2+}$ release by the increase of inositol-1, 4, 5-triphosphate.

• 한국미생물·생명공학회지
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• 제5권4호
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• pp.177-184
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• 1977

Arylsulfatase는 간단한 Phenols류의 황에스테르 화합물로부터 S $O_{4}$$^{[-992]}$ - 이온의 유리를 촉매한다. 이 효소는 토양센균을 포함한 많은 미생물과 동식물의 조직등에 널리 분포하여 있으며 이와 같은 넓은 분포는 이 효소의 기본적 기능이 환경학적으로 매우 중요한 의미를 갖는다고 하겠다. Arylsulfatase에 대한보고는 Klebsiella sp를 사용하여 몇몇 보고가 있다. 본 연구는 6종의 Serratia sp를 사용하여 arylsulfatase 합성조건을 검토하고 효소의 정제조건과 성질에 대하여 조사하여 Serratia marcescens를 선정하였다. Serratia mrcescens는 탄소원으로서 xylose rhamnose, glucosamine 그리고 arabinose등과 같은 몇몇 당을 이용하지 못했으며 glucose와 mannitol을 잘 이용하였으나 glucose methioniue의 경우 효소 합성을 억제시키었다. 유황원으로서는 무기유황염과 methionine의 첨가는 억제되었으며 tyramine의 첨가에 의해서 효소 함성의 억제효과는 해제되었다. 효소의 정제는 황산암모늄 포화용액의 분획과 DEAE-Cellulose, CM-Cellulose 그리고 DEAE-Sephadex A-25로 연결되는 구분 분획에 의해서 행하여졌다. 효소의 분자량은 SDS-gelelectrophoresis와 Sephadex G-100 column chromatography에 의하여 각각 46,000과 49,000으로 측정되었고 최적 PH는 6.8이었다. P-Nitrophenyl sulfate를 사용한 Km과 Vmak치는 각각 2.5$\times$$10^{4-}$M과 20 nmoles/min/mg protein이었다. 기질에 대한 특성은 phenylsulfte와 ο-, p-nit-rophenyl sulfate 그리고 p-nitro catechol sulfate에 대해서 높은 활성을 보였다. Hydroxylamine, inorganic fluoride, sulfide 그리고 Phosphate등은 강한 효소 저해작용을 나타내었고 무기유산염은 저해작용을 보여주지 않았다. Tyramine, octopamine그리고 dopamine과 같은 amino acid 또한 강한 저해 작용을 보였다.

• The Korean Journal of Physiology and Pharmacology
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• 제10권5호
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• pp.289-295
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• 2006

Sodium fluoride (NaF) has been shown to be cytotoxic and elicit inflammatory response in human. However, the cellular mechanisms underlying NaF-induced cytotoxicity in periodontal tissues have not yet been elucidated. This study is aimed to investigate the mechanisms of NaF-induced apoptosis in human gingival fibroblast (HGF). NaF decreased the cell viability of HGF in a dose- and time-dependent manner. NaF gave rise to apoptotic morphological changes including cell shrinkage, chromatin condensation, and DNA fragmentation. However, NaF did not affect the production of ROS. In addition, NaF augumented cytochrome c release from mitochondria into the cytosol, and enhanced caspase -9 and -3 activities., cleavage (85 kDa fragments) of poly (ADP-ribose) polymerase (PARP) and upregulation of voltage-dependent anion channel (VDAC) 1. These results demonstrated that NaF-induced apoptosis in HGF may be mediated with mitochondria. Furthermore, NaF elevated caspase-8 activity and upregulated Fas-ligand (Fas-L), suggesting involvement of death receptor mediated pathway in NaF-induced apoptosis. Expression of Bcl-2, an anti-apoptotic Bcl-2 family, was downregulated, whereas expression of Bax, a pro-apoptotic Bcl-2 family, was not affected in NaF-treated HGF. These results suggest that NaF induces apoptosis in HGF through both mitochondria- and death receptor-mediated pathway mediated by Bcl-2 family.

• International Journal of Oral Biology
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• 제35권2호
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• pp.51-60
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• 2010

Few studies have evaluated the apoptosis-inducing efficacy of NaF on cancer cells in vitro but there has been no previous investigation of the apoptotic effects of NaF on human oral squamous cell carcinoma cells. In this study, we have investigated the mechanisms underlying the apoptotic response to NaF treatment in the YD9 human squamous cell carcinoma cell line. The viability of YD9 cells and their growth inhibition were assessed by MTT and clonogenic assays, respectively. Hoechst staining, DNA electrophoresis and TUNEL staining were conducted to detect apoptosis. YD9 cells were treated with NaF, and western blotting, immunocytochemistry, confocal microscopy, FACScan flow cytometry, and MMP and proteasome activity assays were performed sequentially. The NaF treatment resulted in a time- and dose-dependent decrease in YD9 cell viability, a dose-dependent inhibition of cell growth, and the induction of apoptotic cell death. The apoptotic response of these cells was manifested by nuclear condensation, DNA fragmentation, the reduction of MMP and proteasome activity, a decreased DNA content, the release of cytochrome c into the cytosol, the translocation of AIF and DFF40 (CAD) into the nucleus, a significant shift of the Bax/Bcl-2 ratio, and the activation of caspase-9, caspase-3, PARP, Lamin A/C and DFF45 (ICAD). Furthermore, NaF treatment resulted in the downregulation of G1 cell cyclerelated proteins, and upregulation of p53 and the Cdk inhibitor $p27^{KIP1}$. Taken collectively, our present findings demonstrate that NaF strongly inhibits YD9 cell proliferation by modulating the expression of G1 cell cycle-related proteins and inducing apoptosis via mitochondrial and caspase pathways.

• 대한핵의학회지
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• 제28권3호
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• pp.331-337
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• 1994

In order to develop a $^{18}F$-labelled myocardial perfusion agent(flow tracer) for PET, $^{18}F$-labelled organic ammonium cations were synthesized and evaluated in relation to their biodistribution. Five quaternary organic ammonium compounds were labelled with $^{18}F$ in a side chain with moderate to good yields by direct introduction of $^{18}F$-fluoride. Radiochemical yields have been achieved in 30-40min by the precursors (tosylates) in dimethylsulfoxide 15-60% (decay corrected). The reaction was found to be autocatalyzed. A remote controlled procedure was developed in these synthesis. $^{18}F$-Labelling and HPLC-purification of com-pounds needed about 60 min(Yield; 7-20%). Up to now the two compounds N-4-[$^{18}F$]fluorobutyl-pyridinium cation(1) and N, N dibenzyl-4(2-[$^{18}F$]fluoroethyl)piperidinium cation(2) were investigated in relation to their biodistribution in mice. Compound 1 showed at 1 min post injection the high uptake of 19.22% ID/g organ in the myocardium but a following fast decline to 1.12% ID/g organ after 40min. Uptake of compound 2 was after 1min in the heart 5.90% ID/g organ but after 40min at the relative high value of 4.33% ID/g organ. Heart:blood ratio for compound(1) at 1 min was 8.3, at 40 min 2.6 for compound II 2.0(1min) and 15.0(40 min). As data of compound 2 showed greater heart uptake, slower myocardial release, and higher heart: blood ratios, compound 2 is a good candidate for further evaluation.

• Restorative Dentistry and Endodontics
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• 제22권2호
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• pp.622-636
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• 1997

Glass ionomer cements, which had been developed in 1972, were widely used as an agent for cementation, base, pit and fissure sealant, and esthetic filling material with the advantages of excellent biocompatibility, anti-cariogenic fluoride release. Specimens were made to evaluate the color change of Glass ionomer cement with a newly developed improved Fuji II Le. Specimens for color change study with cement thickness of 1, 2, 3mm were made and those for the study of color shift pattern were made with the assumption that new mid-shade can be made by mixing of equal amount of both shades in 2mm thickness. After 24 hours in a $37^{\circ}C$ incubator, CIELAB color spaces were evaluated with a spectrophotometer. The results were as follows ; 1. All specimens discolored to dark and blue with an increased thickness in all shades (p<0.05). 2. There were significant $a^*$ space (red-green direction) changes in every A, B, C, D shade series except the relationship between 1mm and 2mm thickness groups in B shade series. But the changes were irregular, i.e., each shade series has its own pattern. 3. Each shade series showed its own specific color shift pattern in all $L^*$, $a^*$, $b^*$ spaces. 4. B shade series showed less amont of changes in ${\Delta}{\pm}E$ than those of A and C shade series (p<0.05), but there was no significant difference in ${\Delta}E$ within each shade series.