• The Korean Journal of Physiology and Pharmacology
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• 제2권4호
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• pp.461-469
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• 1998

Tetrahydroisoquinoline (THI) alkaloids can be considered as cyclized derivatives of simple phenylethy-lamines, and many of them, especially with 6,7-disubstitution, demonstrate relatively high affinity for catecholamines. Two -OH groups at 6 and 7 positions are supposed to be essential to exert ?${\beta}-receptor$ activities. However, it is not clear whether -OH at 6,7 substitution of THIs also shows ?${\alpha}-adrenoceptor$ activities. In the present study, we investigated whether -OH or $-OCH_3$ substitutions of 6,7 position of THIs differently affect the ?1-adrenoceptor affinity. We synthesized two 1-naphthylmethyl THI alkaloids, $1-{\beta}-naphthylmethyl-6,7-dihydroxy-1,2,3,4-tetrahydroisoquinoline$ HBr (YS 51) and $1-{\beta}-naphthylmethyl-6, 7-dimethoxy-1,2,3,4-tetrahydroisoquinoline$ HCl (YS 55), and their pharmacological actions on ?${\alpha}_1-adrenoceptor$ were compared. YS 51 and YS 55, concentration-dependently relaxed endothelium-denuded rat thoracic aorta precontracted with phenylephrine (PE, 0.1 ${\mu}M$) in which $pEC_{50}$ were $5.89{\pm}0.21$ and $5.93{\pm}0.19$, respectively. Propranolol (30 nM) did not affect the relaxation-response curves to YS 51 and YS 55. Concentration-response curves to PE were shifted to right by the pretreatment with YS 51 or YS 55. The $pA_2$ values of YS 51 and YS 55 showed $6.05{\pm}0.24$ and $5.88{\pm}0.16$, respectively. Both probes relaxed KCl (65.4 mM)-contracted aorta and inhibited $CaCl_2-induced$ contraction of PE-stimulated endothelium- denuded rat thoracic aorta in $Ca^{2+}-free$ solutions. In isolated guinea pig papillary muscle, 1 and 10 ${\mu}M$ YS 51 increased contractile force about 4- and 8- fold over the control, respectively, along with the concentration-dependent increment of cytosolic $Ca^{2+}$ ions. While, 10 ${\mu}M$ YS 55 reduced the contractile force about 50 % over the control and lowered the cytosolic $Ca^{2+}$ level, in rat brain homogenates, YS 51 and YS 55 displaced $[^3H]prazosin$ binding competitively with Ki 0.15 and 0.12 ${\mu}M$, respectively. However, both probes were ineffective on $[^3H]nitrendipine$ binding. Therefore, it is concluded that two synthetic naphthylmethyl-THI alkaloids have considerable affinity to ?1-adrenenoceptors in rat aorta and brain.

• The Korean Journal of Physiology and Pharmacology
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• 제2권3호
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• pp.323-330
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• 1998

Tetrahydroisoquinoline (THI) alkaloids can be considered as cyclized derivatives of simple phenylethylamines. Many of them, especially with 6,7-disubstitution, demonstrate a relatively high affinity for catecholamines. Present study examines the pharmacological action of limited series of THI, using rats' isolated atria and aorta. In addition, a $[^3H]$ prazosin displacement binding study with THI compounds was performed, using rat brain homogenates to investigate whether these probes have ?${\alpha}$-adrenoceptor affinity. We also compared the vascular relaxation potency of these probes with dobutamine. YS 49, YS 51, higenamine and dobutamine, concentration-dependently, relaxed endothelium-denuded rat thoracic aorta precontracted with phenylephrine (PE, 0.1 ${\mu}M$) in which $pEC_{50}$ were $5.56{\pm}0.32$ and $5.55{\pm}0.21$, $5.99{\pm}1.16$ and $5.57{\pm}0.34$, respectively. These probes except higenamine also relaxed KCl (65.4 mM)-contracted aorta. In isolated rat atria, all THIs and dobutamine increased heart rate and contractile force. In the presence of propranolol, the concentration response curves of YS 49 and YS 51 shifted to the right and resulted in $pA_2$ values of $8.07{\pm}0.84$ and $7.93{\pm}0.11$, respectively. The slope of each compound was not deviated from unity, indicating that these chemicals are highly competitive at the cardiac ?${\beta}-adrenoceptors$. YS 49, YS 51, and higenamine showed ?${\alpha)-adrenoceptor$ affinity in rat brain, in which the dissociation constant $(K_i)$ was 2.75, 2.81, and 1.02 ${\mu}M$, respectively. It is concluded, therefore, that THI alkaloids have weak affinity to ${\alpha)_1-adrenoceptor$ in rat aorta and brain, respectively, while these probes show relatively high affinity for cardiac ${\beta}-adrenoceptors$. Thus, these chemicals may be useful in the treatment of congestive heart failure.

• 대한소아치과학회지
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• 제27권4호
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• pp.549-557
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• 2000

치아우식증은 치아구조의 국소적, 침윤적, 분자적인 붕괴로 특징지워지는 치아 경조직에 대한 세균성질환이다. 이런 치아 우식증의 주 원인균인 S. mutans의 치태형성과 증식에 대해 아동의 구강에서 분리된 L. lactis 51의 작용을 연구하여 다음과 같은 결과를 얻었다. 1. 비커 와이어 검사에서 S. mutans와 L. lactis 51의 혼합배양시 S. mutans 단독배양에 비해 치태의 무게가 감소하였다. 2. S. mutans는 S. mutans와 L. lactis 51의 혼합 배양에 비교하여 S. mutans 단독배양시에 생균수가 감소하였다. 3. S. mutans와 L. lactis 51은 M17Y broth에서 단독 및 혼합배양시 배양 12시간 때까지 증가하다가 24시간 때에 감소 하였으나, M17YS broth에서는 S. mutans와 L. lactis 51의 혼합배양시 S. mutans의 생균수가 시간이 지남에 따라 감소하였다. 4. L. lactis 51의 배양 상청액은 S. mutans의 치태형성과 증식에 대해 억제 작용을 하지 못하였다. 5. M17YS broth에서의 L. lactis 51 배양 상청액 성분의 thin layer chromatography에서 자당과 과당이 계속 검출되었다. 이상의 결과를 종합하면 구강에서 분리된 L. lactis 51는 S. mutans의 인공치태 형성과 증식을 억제시키는 것으로 사료된다.

• 대한약학회:학술대회논문집
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• 대한약학회 2001년도 Proceedings of the Pharmaceutical Society of Korea
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• pp.126.1-126.1
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• 2001

• 항공우주
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• 제26권
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• pp.47-51
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• 1995

• 대한약학회:학술대회논문집
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• 대한약학회 2005년도 Proceedings of the Convention of the Pharmaceutical Society of Korea Vol.2
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• pp.254-254
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• 2005

• 한국응용약물학회:학술대회논문집
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• 한국응용약물학회 2004년도 Annual Meeting of KSAP : New Drug Development from Natural Products
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• pp.3-10
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• 2004

Oxidative stress is a constant threat to all living organisms and an immense repertoire of cellular defense systems is being employed by most pro- and eukaryotic systems to eliminate or to attenuate oxidative stress. Ischemia and reperfusion is characterized by both a significant oxidative stress and characteristic changes in the antioxidant defense. Heme oxigenase-l (HO-l) is up-regulated by various stimuli including oxidative stress so that it is thought to participate in general cellular defense mechanisms against ischemic injury in mammalian cells. Higenamine, an active ingredient of Aconite tuber, has been shown to have antioxidant activity along with inhibitory action of inducible nitric oxide synthase (iNOS) expression in various cells. In the present study, we investigated whether higenamine and related analogs protect cells from oxidative cellular injuries by modulating antioxidant enzymes, such as HO-l, MnSOD etc. R-form of YS-51 was the most potent inducer of HO-l in bovine endothelial cells, which inhibited apoptotic cell death by H$_2$O$_2$. HO-1 induction by YS 51 was mediated by PI3 kinase activation in which PKA- as well as PKG pathway is considered as important regulators. YS-51 also induced Mn-SOD mRNA expression by activating c-jun N-terminal kinase in endothelial cells and Hela cells. In ROS 17/2.1 cells, higenamine and enetiomers of related compounds inhibited iNOS expression by cytokine mixtures. Taken together, higenamine and related compounds can be developed as possible protective agents from oxidative cell injury or death.

• 한국세라믹학회지
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• 제35권3호
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• pp.273-279
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• 1998

Unite cell of soid oxide fuel cell (SOFC) that consists of a dense yttria-stabilized zirconia(YSZ) electrolyte a porous nickel-YSZ cermet anode and a porous strontium- doped lanthanum manganate(LSM) cathod was fabricated from using pore former through co-firing technique. Initial sintering shrinkage rates of each layer were identified for fabricating SOFC. Heterogenous sintering was very effective in tailoring shrinkage rate for three layers. The powder tailoring necessary for shrinkage rate matching are as follows ; electrolyte of 60% TZ8YS/ 40% TZ8Y mixture anode of 51wt% NiO/49 wt% (70wt% TZ8YS/30 wt% UT ZrO2) mixture and cathode of 80% LSM/20% UT ZrO2 mixture . The overall sintering shrinkage rate differences of three layers using these compositions were maintained in a few percent.

• 한국식품위생안전성학회지
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• 제31권1호
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• pp.51-58
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• 2016

본 연구는 인체 유방암세포 SK-BR-3, MDA-MB-231과 위암세포 AGS를 대상으로 국화과 식물 중 흰민들레(Taraxacum coreanum, TC), 고들빼기(Youngia sonchifolia, YS), 씀바귀(Ixeris dentate, ID) 추출물에 의한 증식 억제효과를 비교 한 후, 가장 억제효율이 높은 추출물을 선택하여 apoptosis 유도 효과를 조사하였다. 암세포의 증식 억제효과는 TC 추출물에 의한 영향은 약한 반면, YS와 ID 추출물에 의한 영향은 농도 의존적으로 증가하는 것을 확인하였다. 세 가지 추출물 중 가장 효과가 뛰어난 ID 추출물을 이용하여 추가적으로 농도 설정을 진행한 다음 이후 실험을 진행하였다. ID 추출물에 의한 apoptosis 양성 세포를 확인하기 위해 DAPI assay를 진행한 결과, ID 추출물을 처치한 군에서 apoptotic body와 세포질 응축을 확인하였다. MTT assay와 DAPI staining의 결과를 바탕으로 ID 추출물이 SK-BR-3, MDA-MB-231, AGS 세포에서 apoptosis와 관련한 단백질 발현 양상에 미치는 영향을 확인하기 위해 western blot을 실시하였다. ID 추출물에 의해 SK-BR-3, MDA-MB-231, AGS 세포에서 pro-apoptosis인 Bax 단백질 발현은 농도 의존적으로 증가하였고, anti-apoptosis인 Bcl-2 단백질 발현은 SK-BR-3 세포에서는 발현의 변화가 거의 없었지만, MDA-MB-231과 AGS 세포에서는 감소하였다. 세포사멸의 주요임상지표인 Bax/Bcl-2 ratio는 MDA-MB-231세포에서 가장 유의적으로 증가하였다. 또한, 손상된 DNA를 복구하는 단백질인 PARP의 발현은 감소하면서, cleaved-PARP이 증가하였다. 이러한 결과들을 종합하였을 때, YS와 ID 추출물은 TC 추출물에 비해 암세포의 생존을 효과적으로 억제하였고, 특히 ID 추출물은 낮은 농도에서도 암세포의 생존 억제효과가 우수한 것을 확인하였다. 또한, ID 추출물에 의한 유방암세포 SK-BR-3, MDA-MB-231와 위암세포 AGS의 생존율 억제는 apoptosis 유도를 통해 이루어 지는 것으로 사료되며, 그 중 유방암세포 MDA-MB-231에서 apoptosis 유도 효과가 뛰어난 것을 미루어 보아, 유방암의 종류와 그 특징에 따른 차이를 보이지만 ID는 향후 유방암 예방 및 치료제로 개발 가능성을 제시하며, 추후 지속적인 연구를 통하여 in vivo에서의 ID 추출물의 항암효과에 대해 심도 있는 연구가 이루어 져야 할 것으로 사료된다.

• 한국재료학회지
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• 제30권2호
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• pp.51-56
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• 2020

In this study, three kinds of metal chills such as SS400, AC4CH and brass, with different thicknesses of 40 ~ 80 mm, were applied for low pressure casting of Al-Si alloy to control cooling rate. The microstructural characteristics with increasing cooling rate were represented using factors including D₁, D₂, size of primary α phases and shape factor and size of eutectic Si. The tensile properties were investigated and additionally analyzed based on the microstructural characteristics. As the cooling rate increased, D₁, D₂, and sizes of primary α phases and eutectic Si apparently decreased and the shape factor of eutectic Si increased to over 0.8. The ultimate tensile strength (UTS) and yield strength (YS) increased with decreasing D₁, D₂, and size of primary α phases, while elongation increased with decreasing size of eutectic Si and concurrently increasing shape factor of eutectic Si. This indicated that the primary α phases and eutectic Si in Al-Si alloy were refined with increasing cooling rate, resulting in improvement of UTS and YS without sacrificing elongation. After the tensile test, preferential deformation of primary α phases was observed in the Al-Si alloy produced at higher cooling rates of more than 0.1 K/s.