• The Korean Journal of Physiology and Pharmacology
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• 제1권2호
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• pp.135-142
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• 1997

As it has been reported that the depolarization-induced norepinephrine (NE) release is modulated by activation of presynaptic $A_1$-adenosine heteroreceptor and various lines of evidence indicate that $A_2$-adenosine receptor also presents in hippocampus, and that the adenosine effect is magnesium dependent, the present study was undertaken to delineate the role of adenosine receptors in the modulation of hippocampal NE release. Slices from the rat hippocampus were equilibrated with $[^3H]-NE$ and the release of the labelled product, $[^3H]-NE$, was evoked by electrical stimulation (3 Hz, 5 V $cm^{-1}$, 2 ms, rectangular pulses), and the influence of various agents on the evoked tritium outflow was investigated. $N^6-cyclo-pentyladenosine$ (CPA), in concentrations ranging from 0.1 to 10 ${\mu}M$, decreased the $[^3H]-NE$ release in a dose-dependent manner without changing the basal rate of release, and these effects were significantly inhibited by 8-cyclopentyl-1,3-dipropylxanthine (DPCPX, 2 ${\mu}M$) treatment. When the magnesium concentration was reduced to 0.4 mM or completely removed, the evoked NE release increased along with decreased basal rate of release. In contrast, increasing the magnesium concentrations to 2.4 and 4 mM, decreased the evoked NE release. The CPA effects on evoked NE release were reducedby magnesium removal, but potentiated by 2.4 mM magnesium in the medium. 5-(N-cyclopropyl)-carboxamodiadenosine (CPCA, 1 & 10 ${\mu}M$), an $A_2$-agonist, decreased the evoked tritium outflow, and this effect was also abolished by DPCPX pretreatment. CGS, a powerful $A_2$-agonist, did not affect the evoked NE release. However, the effects of CPCA and CGS on evoked NE release were significantly increased by pretreatment of DPCPX in the magnesium-free medium. These results indicate that inhibitory effect of $A_1$-adenosine receptor on NE release is magnesium-dependent, and $A_2$-receptor may be present in the rat hippocampus.

• 한국콘텐츠학회논문지
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• 제18권3호
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• pp.542-549
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• 2018

본 연구는 불소 미방출 치면열구전색제 $Concise^{TM}$에 제조한 생체활성 유리 나노입자(bioactive glass nano particles: BGn)를 0.5, 1.0, 2.0 wt%를 첨가하여 새로운 치면열구전색제를 조성하고 세균부착실험을 통한 세균부착 억제 효과와 물성을 평가 하였다. 물흡수도와 용해도는 ISO 4049(2009) 규격에 맞추어 직경 10 mm, 두께 2 mm 시편을 제작하여 무게를 측정하여 산출하였으며 세균부착효과는 S. mutans, S. aureus, E. coli 3개의 균주를 이용하여 평가하였다. 실험 결과 물흡수도는 BGn 첨가가 증가할수록 높은 값을 보였으며 용해도는 첨가될수록 낮은 용해도를 보였다(p<0.05). 세균부착실험 결과 대조군 $Concise^{TM}$과 비교하여 BGn을 첨가한 S. mutans 실험군에서 다소 낮은 부착 양상을 보였으나 통계적 유의한 차이는 나타나지 않았으나, S. aureus 실험군과 E.coli 실험군에서는 통계적 유의한 차이를 보였다(p<0.05). 이는 BGn의 세균부착 억제 효과가 있음을 입증한 것이라 사료된다. 향후 BGn 첨가양에 따른 효율성과 폭 넓은 물성 연구가 필요할 것으로 사료된다.

• Asian Pacific Journal of Cancer Prevention
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• 제16권9호
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• pp.3595-3604
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• 2015

Hepatocellular carcinoma (HCC) has been one of the most fatal malignant tumors worldwide and its associated morbidity and mortality remain of significant concern. Based on in-depth reviews of serological diagnosis of HCC, in addition to AFP, there are other biomarkers: Lens culinaris agglutinin-reactive AFP (AFP-L3), descarboxyprothrombin (DCP), tyrosine kinase with Ig and eprdermal growth factor (EGF) homology domains 2 (TIE2)-espressing monocytes (TEMs), glypican-3 (GPC3), Golgi protein 73 (GP73), interleukin-6 (IL-6), and squamous cell carcinoma antigen (SCCA) have been proposed as biomarkers for the early detection of HCC. The diagnosis of HCC is primarily based on noninvasive standard imaging methods, such as ultrasound (US), dynamic multiphasic multidetector-row CT (MDCT) and magnetic resonance imaging (MRI). Some experts advocate gadolinium diethyl-enetriamine pentaacetic acid (Gd-EOB-DTPA) MRI and contrast-enhanced US as the promising imaging madalities of choice. With regard to recent advancements in tissue markers, many cuting-edge technologies using genome-wide DNA microarrays, qRT-PCR, and proteomic and inmunostaining studies have been implemented in an attempt to identify markers for early diagnosis of HCC. Only less than half of HCC patients at initial diagnosis are at an early stage treatable with curative options: local ablation, surgical resection, or liver transplant. Transarterial chemoembolization (TACE) is considered the standard of care with palliation for intermediate stage HCC. Recent innovative procedures using drug-eluting-beads and radioembolization using Yttrium-90 may exhibit beneficial effects in HCC treatment. During the past few years, several molecular targeted agents have been evaluated in clinical trials in advanced HCC. Sorafenib is currently the only approved systemic treatment for HCC. It has been approved for the therapy of asymptomatic HCC patients with well-preserved liver function who are not candidates for potentially curative treatments, such as surgical resection or liver transplantation. In the USA, Europe and particularly Japan, hepatitis C virus (HCV) related HCC accounts for most liver cancer, as compared with Asia-Pacific regions, where hepatitis B virus (HBV) may play a more important role in HCC development. HBV vaccination, while a vaccine is not yet available against HCV, has been recognized as a best primary prevention method for HBV-related HCC, although in patients already infected with HBV or HCV, secondary prevention with antiviral therapy is still a reasonable strategy. In addition to HBV and HCV, attention should be paid to other relevant HCC risk factors, including nonalcoholic fatty liver disease due to obesity and diabetes, heavy alcohol consumption, and prolonged aflatoxin exposure. Interestingly, coffee and vitamin K2 have been proven to provide protective effects against HCC. Regarding tertiary prevention of HCC recurrence after surgical resection, addition of antiviral treatment has proven to be a rational strategy.

• Asian Pacific Journal of Cancer Prevention
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• 제15권17호
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• pp.7229-7234
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• 2014

Trichoderma spp. are known as a rich source of secondary metabolites with biological activity belonging to a variety of classes of chemical compounds. These fungi also are well known for their ability to produce a wide range of antibiotic substances and to parasitize other fungi. In search for new substances, which might act as anticancer agents, the overall objective of this study was to investigate the cytotoxic effects of Trichoderma harzianum and Trichoderma asperellum cultural filtrates against human cervical and breast cancer cell lines (HeLa and MCF-7 cells respectively). To achieve this objective, cells were exposed to 20, 40, 60, 80 and 100 mg/ml of both T. harzianum cultural filtrate (ThCF) and T. asperellum cultural filtrate (TaCF) for 24h, then the cell viability and the cytotoxic responses were assessed by using trypan blue and 3-(4,5-dimethylthiazol-2yl)-2,5-biphenyl tetrazolium bromide (MTT) assays. Morphological changes in cells were investigated by phase contrast inverted microscopy. The results showed that ThCF and TaCF significantly reduce the cell viability, have cytotoxic effects and alter the cellular morphology of HeLa and MCF-7 cells in a concentration dependent manner. A concentration of 80 and 100mg/ml of ThCF resulted in a sharp decline in the cell viability percent of HeLa and MCF-7 respectively (25.2%, 26.5%) which was recorded by trypan blue assay. The half-maximal inhibitory concentrations ($IC_{50}$) of ThCF and TaCF in HeLa and MCF-7 were recorded as 16.6, 12.0, 19.6 and 0.70mg/ml respectively by MTT assay. These results revealed that ThCF and TaCF have a substantial ability to reduce the viability and proliferation of human cervical and breast cancer cells.

• 지역연구
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• 제13권2호
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• pp.55-74
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• 1997

This paper investigates the spatial characteristics of networks, which arise as a firm's strategy to enhance its competitiveness to cope with the changing economic environments characterized by technological changes and increasing competitiveness. The theoretical framework in this study proposes that networks emerge as a firm's strategies to promote its competitiveness through the vertical/horizontal disintegration of the production system. Futhermore, regional industries of networks. The study examines the types of cooperation and the spatial boundary of the computer industry networks in Korea. Questionnaire survey was conducted on 1, 128 computer companies which had more than 10 employees, with 126 questionnaires being used for analysis. In addition, newpaper articles were used to supplement the foregoing work on network characteristics. The review of these articles covers the period from Jan. 1994 to June 1996. Major findings of this study are as follows: The spatial range of cooperative networks varies according to the specific characters of cooperation(R & D, production, and seles). Intralocal networks are being developed in Kangnam and Youido area, the computer industry agglomeration clusres of Seoul. There are the regional differnces in the agents and contents of cooperation. In intra-national R & D and production networks, regional differnces in agglomeratins and non-agglomerations are not detercted. Most networks of this type are found between large firms and small firms. In contrast, foregn R & D and production networks, which are operated mostly by large firms, are found in Kangnam, Youido, and CBD. Intra-national and foreign productino networks are also focused in Kangnam, Youido, and CBD. Small firms are playing an active role in making this type of cooperation possible. In the perspective of localization-globalization, Korean computer industry can be analyzed in two respects: industrial and regional. The localization of small firms and the localization-globalization of large firms' networks are being developed in industrial contexts, while the localization-globalization of agglomerations and the localization of non-agglomerations networks are being developed in regional contexts. As networks for the localization-globalization of industry are growing in agglomerations, interfirm networks could be related to trends in the formation or intensification of industrial agglomerations. industrial agglomeration areas function as a facilitator of localization through subcontracts, intraregional network and interregional network. They also facilitate globalization via foregn networks. In non-agglomeratin areas, localization networks, which are connected with agglomeration areas via subcontracting, interregional R & D. or production cooperation.

• 대한약리학회지
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• 제2권1호
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• pp.71-82
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• 1966

The inhibitory effect of 5-hydroxytryptamine (5-HT) on the isolated intestinal strips of the tortoise (Amyda japonica), rat, rabbit and guinea pig was investigated. 1) The strips from the middle or lower part of the tortoise intestine responded with relaxation to 5-HT $(10^{-9}{\sim}10^{-5}g/ml)$, and the magnitude of the relaxation was proportional to the dose of 5-HT. The rectal part of the tortoise intestine, in contrast, showed contraction, the magnitude of which also was proportional to the dose of 5-HT. 2) Various blocking agents such as methysergide, morphine, tetracaine, nethalide, bretylium, hexamethonium, mecamylamine and chlorisondamine, showed no selective blocking activity on the relaxant effect of 5-HT on the tortoise intestine. The inhibitory effect of isoproterenol on the tortoise intestine, however, was selectively blocked by nethalide, and the stimulatory effect of 5-HT on the rectal part of the tortoise was blocked by methysergide. 3) In the presence of 5-HT, the stimulatory effect of DMPP on the tortoise intestine was remarkably attenuated, whereas that of acetylcholine and $BaCl_2$ was little affected. In the presence of isoproterenol, the stimulatory effect of acetylcholine and $BaCl_2$ were affected, but that of DMPP was little affected. 4) Large dose of 5-HT($10^{-4}$g/ml) produced inhibitory effect on the strips from the distal part of the isolated colon of the rat, rabbit and guinea pig, when the strips had been exposed to 5-HT($10^{-4}$g/ml), methysergide or phen`oxybenzamine. 5) Bretylium, as well as nethalide, abolished or remarkably reduced, in a few cases of the experiments, the inhibitory effect of the large dose of 5-HT on the distal part of the colon, whereas morphine did not affect it. 6) The ileal strips of the guinea pig also showed relaxation, as in the colonic strips, having been exposed to the large dose of 5-HT or phenoxybenzamine. This effect, however, was not obsered in the case of the rabbit ileum. 7) The property of the action-site of 5-HT in the tortoise intestine seemd to be different from the 5-HT receptors which have been revealed by several investigators. 8) Adrenergic component seemed to be participated in the inhibitory effect of 5-HT on the colon of the rat and rabbit.

• 생명과학회지
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• 제21권11호
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• pp.1501-1510
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• 2011

최근에 해양자원에 있는 동물, 해조류 곰팡이 세균에서 신규 잠재적인 후보약효제가 조사되어 왔다. 본 연구에서는 치료제를 탐색하기 위하여 암전이, 관절염, 만성염증 및 주름형성에 주요한 역할을 하는 기질금속단백질분해효소(s) (MMPs)를 목적효소로 이용하였다. 5종의 녹조류, 18종의 홍조류, 4종의 갈조류를 포함한 다양한 해조류가 사람피부섬유아세포 및 섬유아육종세포로부터 유래된 기질금속단백질효소에 미치는 영향을 gelatin zymography를 이용하여 조사하였다. 사람피부섬유아세포에서는 홍조류중에서 Laurencia okamurae, Polysiphonia japonica, Grateloupia lanceolate 및 Sinkoraena lancifolia에서 MMP-2 억제효과가 관찰되었다. 반면에 녹조류의 Enteromorpha compressa와 Enteromorpha linza, 갈조류의 Peltaronia bighamiae and Sargassum thunbergii에서는 MMP-2 활성화가 관찰되었다. 사람섬유아육종세포에서는 MMP-9 활성화가 갈조류인 Sargassum thunbergii, 홍조류의 Polysiphonia japonica, 녹조류의 Enteromorpha compressa와 Enteromorpha linza의 존재 하에서는 감소되었다. 본 연구에서 흥미로운 발견은 녹조류의 E. compressa와 E. linza 및 갈조류의 S. thunbergii는 정상세포에서는 MMP-2에 대하여 활성화 효과를 나타내었으나, 암세포에서는 MMP-9응 억제하는 효과를 나타낸 것이다. 이러한 결과는 녹조류의 E. compressa와 E. linza 및 갈조류의 S. thunbergii는 항암 효능을 발휘할 수 있는 성분을 함유하고 있다는 것을 암시하고 있다.

• The Journal of Advanced Prosthodontics
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• 제6권3호
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• pp.233-240
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• 2014

PURPOSE. To evaluate the effects of different abutment geometries in combination with varying luting agents and the effectiveness of different cleaning methods (prior to re-cementation) regarding the retentiveness of zirconia copings on implants. MATERIALS AND METHODS. Implants were embedded in resin blocks. Three groups of titanium abutments (pre-fabricated, height: 7.5 mm, taper: $5.7^{\circ}$; customized-long, height: 6.79 mm, taper: $4.8^{\circ}$; customized-short, height: 4.31 mm, taper: $4.8^{\circ}$) were used for luting of CAD/CAM-fabricated zirconia copings with a semi-permanent (Telio CS) and a provisional cement (TempBond NE). Retention forces were evaluated using a universal testing machine. Furthermore, the influence of cleaning methods (manually, manually in combination with ultrasonic bath or sandblasting) prior to re-cementation with a provisional cement (TempBond NE) was investigated with the pre-fabricated titanium abutments (height: 7.5 mm, taper: $5.7^{\circ}$) and SEM-analysis of inner surfaces of the copings was performed. Significant differences were determined via two-way ANOVA. RESULTS. Significant interactions between abutment geometry and luting agent were observed. TempBond NE showed the highest level of retentiveness on customized-long abutments, but was negatively affected by other abutment geometries. In contrast, luting with Telio CS demonstrated consistent results irrespective of the varying abutment geometries. Manual cleaning in combination with an ultrasonic bath was the only cleaning method tested prior to re-cementation that revealed retentiveness levels not inferior to primary cementation. CONCLUSION. No superiority for one of the two cements could be demonstrated because their influences on retentive strength are also depending on abutment geometry. Only manual cleaning in combination with an ultrasonic bath offers retentiveness levels after re-cementation comparable to those of primary luting.

• Bulletin of the Korean Chemical Society
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• 제29권7호
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• pp.1303-1310
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• 2008

Inhibitors of farnesyltransferase (FT), a key enzyme in the post-translational modifications of Ras proteins, have been extensively studied as novel anticancer agents in the preclinical stages, some of which are currently in clinical development. Previously, it has been reported that a novel FT inhibitor LB42907 inhibits Ras farnesylation in the nanomolar range in vitro. The aim of this study was to assess the antitumor efficacy of LB42907 in vitro and in vivo. Anchorage-independent growth of various human tumor cell lines was potently inhibited by treatment with LB42907, comparable to other FT inhibitors in clinical development. In the nude mouse, oral administration of LB42907 demonstrated potent antitumor activity in several human tumor xenograft models including bladder, lung and pancreas origin. Interestingly, significant tumor regression in EJ (bladder) and A549 (lung) xenografts was induced by LB42907 treatment. The effectiveness of LB42907 was also investigated in simultaneous combination with paclitaxel, vincristine, cisplatin or gemcitabine against NCI-H460, A549, and HCT116 cells in vitro using median-effect analysis. LB42907 markedly synergized with most anticancer drugs tested in this study in NCI-H460 cell. In contrast, LB42907 displayed antagonism or partial synergism with these drugs in A549 and HCT116 cells, depending on the class of combined drugs and/ or the level of cytotoxicity. Our results demonstrate that LB42907 is an effective antitumor agent in vitro and in vivo and combination of LB42907 with other chemotherapeutic drugs results in synergistic or antagonistic effects mainly in a cell line-dependent manner. Further preclinical study is warranted.

• Korean Chemical Engineering Research
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• 제44권2호
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• pp.172-178
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• 2006

메조포러스 실리케이트 물질은 포어 내에 thiol(-SH)기나 amine($-NH_2$)기 등의 관능기를 도입하여 수중의 중금속이온을 제거하는 흡착제로 많이 활용되어왔다. 본 연구는 메조포러스 실리케이트 합성에서 구조형성 전구체로 사용되는 계면활성제가 중금속 이온의 흡착활성점으로도 작용하는지를 조사하고자 하였다. 서로 다른 계면활성제를 사용하는 세가지 메조포러스 실리케이트(SBA-15, MCM-41, HMS)을 합성하여 소성 전 계면활성제가 담지되어 있는 경우와 소성되어 계면활성제가 사라진 경우에 이들의 수중 납이온의 흡착거동을 살펴보았다. 먼저, X선 회절분석 실험과 질소 기체 흡착 거동으로 메조포러스 실리케이트의 메조포어 구조를 확인하였고, FT-IR 분석을 통해 소성 전의 계면활성제의 존재와 소성 후에 계면활성제의 제거를 확인하였다. 중금속인 납이온을 사용하여 이들의 흡착능을 측정한 결과, 모든 소성된 메조포러스 실리케이트 물질과 공중합 고분자를 계면활성제로 이용하는 SBA-15는 수중에서 납이온에 대한 흡착능이 극히 미비한 반면에 각각 dodecylamine과 hexadecyltrimethylammoniumbromide(HDTMA)를 계면활성제로 사용하는 HMS, MCM-41은 소정의 흡착능을 보여주었다. 초기 납이온 농도가 50 ppm, 용액 pH가 5인 흡착 조건에서 얻은 흡착 키네틱 데이터를 pseudo second order kinetic model에 적용하여 계산한 결과, 계면활성제가 담지된 HMS는 115.16 mg/g, 계면활성제가 담지된 MCM-41은 26.60 mg/g의 납이온 흡착능을 나타내었다. 이러한 흡착능은 기존의 다른 메조포러스 실리케이트 흡착제의 흡착능과 유사하며, 그들과 비교하여 계면활성제가 담지된 흡착제는 전처리나 후처리 없이 흡착제로 활용할 수 있는 장점을 가지고 있다.