• Title/Summary/Keyword: blocking effect

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The Antitumor Mechanism and Effects of Tetrodotoxin: a Literature Review (복어독의 주성분인 Tetrodotoxin의 항암 기전, 효과에 대한 문헌 고찰)

  • Cho, Ye Eun;Lee, Seungmin;Yoon, Kang Hyun;Lim, Ji Seok;Lee, Seung Hoon;Choi, Do Young;Lee, Jae Dong
    • Journal of Acupuncture Research
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    • v.32 no.1
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    • pp.97-107
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    • 2015
  • Objectives : The purpose of this study is to explore the antitumor mechanism and effects of tetrodotoxin through a literature review of experimental and clinical studies. Methods : Medical databases, including The Cochrane Library, Pubmed, NDSL, RISS4u and National Assembly Library, were searched for relevant articles published from January 1, 2000 to October 31, 2014 using the keywords 'tetrodotoxin', 'cancer' and 'tumor'. The results were classified into experimental studies(in vitro and in vivo) and clinical studies. Analysis of the results was conducted on several research areas including the mechanism, antitumor effect and adverse effects of tetrodotoxin(TTX). Results : A total of 34 experimental studies(32 in vitro and 2 in vivo) and 3 clinical studies were found in the search. Most of the experimental studies suggested blocking of voltage-gated sodium channels in metastasis of tumor cells as the main antitumor mechanism of TTX. The most common type of cancers mentioned in the experimental studies were prostate and breast cancer. All of the clinical studies were on the application of TTX on moderate to severe cancer-related pain. No adverse effects of TTX were reported in in vivo studies but mild to moderate adverse events were reported in clinical studies. Conclusions : The results show that tetrodotoxin, which is the main component of Tetraodontidae(commonly known as pufferfish) poison, could be clinically used for antitumor therapy. However, further studies should be conducted on its safety.

Arm Cortex S3C2440 Microcontroller Application for Transcranial Magnetic Stimulation's Pulse Forming on Bax Reactive Cells and Cell Death in Ischemia Induced Rats

  • Tac, Han-Ho;Kim, Whi-Young
    • Journal of Magnetics
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    • v.21 no.2
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    • pp.266-272
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    • 2016
  • Transcranial magnetic stimulation devices has been used mainly for diagnostic purposes by measuring the functions of the nervous system rather than for treatment purposes, and has a problem of considerable energy fluctuations per repeated pulse. The majority of strokes are caused by ischemia and result in brain tissue damage, leading to problems of the central nervous system including hemiparesis, dysfunction of language and consciousness, and dysfunction of perception. Control is difficult and the size is large due to the difficulty of digitalizing the energy stored in a capacitor, and there are many heavy devices. In addition, there are many constraints when it is used for a range of purposes such as head and neck diagnosis, treatment and rehabilitation of nerve palsy, muscle strengthening, treatment of urinary incontinence etc. Output stabilization and minimization of the energy variation rate are required as the level of the transcranial magnetic stimulation device is dramatically improved and the demand for therapeutic purposes increases. This study developed a compact, low cost transcranial magnetic stimulation device with minimal energy variation of a high repeated pulse and output stabilization using a real time capacitor charge discharge voltage. Ischemia was induced in male SD rats by closing off the common carotid artery for 5 minutes, after which the blood was re-perfused. In the cerebrum, the number of PARP reactive cells after 24 hours significantly decreased (p < 0.05) in the TMS group compared to the GI group. As a result, TMS showed the greatest effect on necrosis-related PARP immuno-reactive cells 24 hours after ischemia, indicating necrosis inhibition, blocking of neural cell death, and protection of neural cells.

Effect of Aqua-acupuncture Solution of Medicinal Plants on Induction of Anticarcinogenic Phase II Enzymes (생약(生樂) 약침액(藥鍼液)이 암예방(癌豫防) 효소계(酵素系)에 미치는 영향(影響))

  • Lim Jong-Kook;Moon Jin-Young;Cho Kyoung-Hee;Shon Yun-Hee;Nam Kyung-Soo
    • Korean Journal of Acupuncture
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    • v.17 no.1
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    • pp.11-17
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    • 2000
  • Induction of phase II enzymes such as quinone reductase (QR) or glutathione S-transferase (GST) is considered a major mechanism of protection against initiation of carcingenesis. The induction of detoxification enzymes and glutathione were studied with Lonicerae Flos aqua-acupuncture solution (LFAS), Angelicae gigantis Radix aqua-acupuncture solution (AGRAS), and Gamdutang aqua-acupunture solution (GAS) in murine hepatoma cells grown in microtiter plate wells. LFAS, AGRAS and GAS were potent inducers of QR activity. LFAS was induced about 2.6-fold at concentration of $3{\times}$. AGRAS and GAS were also induced about 2.6-, 1.8-fold at concentration of $5{\times}$, respectively. In addition, GST activity was increased with LFAS, AGRAS, and GAS. GSH levels were increased about 2-fold with LFAS at concentration of $5{\times}$, 1.3-fold with AGRAS at concentration of $3{\times}$, and 1.2-fold with GAS at concentration of $5{\times}$. These results suggested that LFAS, AGRAS, and GAS may act as blocking agents against carcinogenesis by induction of phase II marker enzymes.

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The Effects of α-Lipoic Acid in Adilution Solvents, Dose- and Time-dependent Manner on Cell Growth Blocking in 3T3-L1 (α-Lipoic acid의 희석용매, 처리농도, 처리시간에 따른 3T3-L1 지방세포 성장에 미치는 영향)

  • Seo, Eunyoung
    • Journal of the Korean Society of Food Culture
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    • v.33 no.5
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    • pp.464-471
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    • 2018
  • Purpose: This study examined the effects of ${\alpha}$-lipoic acid in diluted solvents on cell growth in 3T3-L1 cells according to the treated concentration and times. Methods: Adipocyte 3T3-L1 cell were cultured. Confluent cells underwent starvation with SFM for 1 day and then were cultured in a medium containing various concentrations 0, 100, 200, and $400{\mu}mol/L$ of ${\alpha}$-lipoic acid. The cell viability was measured using the EZ Cytox assay kit. In addition, the effect of ${\alpha}$-lipoic acid of diluted solvents on the cell growth in 3T3-L1cells was examined according to the treated concentration and times. Results: The ${\alpha}$-lipoic acid diluted ethanol inhibited cell proliferation in a dose and time dependent manner. The ${\alpha}$-lipoic acid diluted ethanol induced adipocyte 3T3-L1 cells proliferation with an adipocyte inducer. In addition, ${\alpha}$-lipoic acid inhibited adipocyte 3T3-L1 growth in a dose and time dependent manner (p<0.05). Conclusion: This study showed that a treatment with ${\alpha}$-lipoic acid diluted ethanol inhibits cell growth of, adipocyte 3T3-L1 cells induced with an adipocyte inducer, ($200{\mu}mol/L$ of ${\alpha}$-lipoic acid) treated for 48 hr.

KF Post Deposition Treatment Process of Cu(In,Ga)Se2 Thin Film Effect of the Na Element Present in the Solar Cell Performance (KF 후열처리 공정시 CIGS 박막의 Na 원소 존재가 태양전지 셀성능에 미치는 영향)

  • Son, Yu-Seung;Kim, Won Mok;Park, Jong-Keuk;Jeong, Jeung-hyun
    • Current Photovoltaic Research
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    • v.3 no.4
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    • pp.130-134
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    • 2015
  • The high efficiency cell research processes through the KF post deposition treatment (PDT) of the $Cu(In,Ga)Se_2(CIGS)$ thin film has been very actively progress. In this study, it CIGS thin film deposition process when KF PDT 300 to the processing temperature, 350, $400^{\circ}C$ changed to soda-lime glass (SLG) efficiency of the CIGS thin film characteristics, and solar cell according to Na presence of diffusion from the substrate the effects were analyzed. As a result, the lower the temperature of KF PDT and serves to interrupt the flow of current K-CIGS layer is not removed from the reaction surface, FF and photocurrent is decreased significantly. Blocking of the Na diffusion from the glass substrate is significantly increased while the optical voltage, photocurrent and FF is a low temperature (300, $350^{\circ}C$) in the greatly reduced, and in $400^{\circ}C$ tend to reduce fine. It is the presence of Na in CIGS thin film by electron-induced degradation of the microstructure of CIGS thin film is expected to have a significant impact on increasing the hole recombination rate a reaction layer is formed of the K elements in the CIGS thin film surface.

Roles of $Ca^{2+}-Activated\;K^+$ Conductances on Spontaneous Firing Patterns of Isolated Rat Medial Vestibular Nucleus Neurons

  • Chun, Sang-Woo;Jun, Jae-Woo;Park, Byung-Rim
    • The Korean Journal of Physiology and Pharmacology
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    • v.4 no.1
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    • pp.1-8
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    • 2000
  • To investigate the contributions of intrinsic membrane properties to the spontaneous activity of medial vestibular nucleus (MVN) neurons, we assessed the effects of blocking large and small calcium-activated potassium channels by means of patch clamp recordings. Almost all the MVN neurons recorded in neonatal $(P13{\sim}P17)$ rat were shown to have either a single deep after-hyperpolarization (AHP; type A cells), or an early fast and a delayed slow AHP (type B cells). Among the recorded MVN cells, immature action potential shapes were found. Immature type A cell showed single uniform AHP and immature B cell showed a lack of the early fast AHP, and the delayed AHP was separated from the repolarization phase of the spike by a period of isopotentiality. Application of apamin and charybdotoxin (CTX), which selectively block the small and large calcium-activated potassium channels, respectively, resulted in significant changes in spontaneous firings. In both type A and type B cells, CTX (20 nM) resulted in a significant increase in spike frequency but did not induce bursting activity. By contrast, apamin (300 nM) selectively abolished the delayed slow AHP and induced bursting activity in type B cells. Apamin had no effect on the spike frequency of type A cells. These data suggest that there are differential roles of apamin and CTX sensitive potassium conductances in spontaneous firing patterns of MVN neurons, and these conductances are important in regulating the intrinsic rhythmicity and excitability.

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Experimental Study and Modelling on Membrane Fouling in Taylor Vortex Flow Microfiltration (테일러 와류 정밀여과에서 막오염의 실험적 연구 및 모델링)

  • 박진용;김현우;최창균
    • Membrane Journal
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    • v.13 no.2
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    • pp.88-100
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    • 2003
  • A change of filtrate flux in Taylor vortex flow filtration was investigated experimentally by rotating speed of inner cellulose ester membrane cylinder (average pore size: 1.2 ${\mu}m$), slurry concentration, and particle size. The filtrate flux was a direct proportion relation with TMP, but an inverse relation with resistances. A change of cake resistance with time was examined by rotating speed, slurry concentration, and particle size. Initial resistance increased dramatically as raising slurry concentration, and the pseudo-steady state was maintained at high resistance value. However, times to reach the pseudo-steady state did not depend on slurry concentration. The resistance was larger as smaller particle size, because possibility of pore blocking inside membrane could be higher and shear effect should be lower as smaller particle size. A model equation suggested in this study was composed of particle deposition and removal terms, and could confirm well experimental data using average values of experimental coefficients.

Influence of SKP 450, a $K^+$ Channel Opener, on the Pressor Actions Induced by Norepinephrine, Angiotensin II and Carotid Artery Occlusion in Rats (Norepinephrine, Angiotensin II 및 경동맥 폐쇄에 의한 혈압 상승작용에 대한 $K^+$ Channel 개방제인 SKP 450의 영향)

  • 고석태
    • Biomolecules & Therapeutics
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    • v.9 no.2
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    • pp.96-103
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    • 2001
  • These studies were investigated about influence of SKP 450, a $K^{+}$ channel opener, on the pressor actions induced by norepinephrine, angiotensin II and carotid artery occlusion in rats. Before these studies, effect of SKP 450 itself on blood pressure was examinated. SKP 450 produced the depressor action in proportionaly to dose of 0.3, 1.0 and 3.0 $\mu$g/kg given intravenously and this depressor action was weakened by pretreatment of glibenclamide, a $K^{+}$ channel blocker. The pressor action induced by norepinephrine, an alpha-adrenergic agonist, was blocked 1 hr after administation of SKP 450 in a dose of 3.0 $\mu\textrm{g}$/kg, i.v. and directly after in a dose of 6.0 $\mu\textrm{g}$/kg, i.v.. The pressor action induced by angiotensin II was blocked immediatly after treatment of SKP 450 in a dose of 3.0 $\mu\textrm{g}$/kg, i.v.. The pressor action caused by carotid artery occlusion was not affected by SKP 450 of 3.0 $\mu\textrm{g}$/kg, i.v., whereas markedly blocked by SKP 450 of 6.0 $\mu\textrm{g}$/㎦, i.v.. The potentiated-pressor actions of norepinephrine and angiotensin II by pretreatment of chlorisondamine, a autonomic ganglionic blocking agent, were also blocked by administration of SKP 450 in a dose of 6.0 $\mu\textrm{g}$/kg, i.v.. The weakened-pressor action of carotid artery occlusion by pretreatment of chlorisondamine was more weakened by SKP 450 6.0 $\mu\textrm{g}$/kg, i.v.. The results suggest that hyperpolarization formed through $K^{+}$ channel opening in cell membrane inhibits the pressor action induced norepinephrine ; angiotensin II ; and carotid artery occlusion.usion.

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Hepatic Gene Expression Analysis of Gadolinium Chloride Treated Mice

  • Jeong, Sun-Young;Lim, Jung-Sun;Hwang, Ji-Yoon;Kim, Yong-Bum;Kim, Chul-Tae;Lee, Nam-Seob;Yoon, Seok-Joo
    • Molecular & Cellular Toxicology
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    • v.2 no.1
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    • pp.21-28
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    • 2006
  • Gadolinium chloride ($GdCl_{3}$) was known to block Kupffer cells and generally its toxicity study based on blocking these cells. Therefore, $GdCl_{3}$ frequently used to study toxic mechanisms of hepatotoxicants inducing injury through Kupffer cells. We also tried to investigate the effect of $GdCl_{3}\;on\;CCl_{4}$ toxicity, typical hepatotoxicants. Administration of $GdCl_{3}$ to mice significantly suppressed AST (asparatate amino transferase), ALT (alanine amino transferase) levels which were increased by $CCl_{4}$ treatment. However, $GdCl_{3}$ didn't inhibit the phagocytotic activity of Kupffer cells. Malondialdehyde (MDA) is a good indicator of the degree of lipid peroxidation. In this study, MDA increased by $GdCl_{3}$ administration not by $CCl_{4}$. To understand the toxicity of $GdCl_{3}$, we analyzed global gene expression profile of mice liver after acute $GdCl_{3}$ injection. Four hundred fifty two genes were differentially expressed with more than 2-fold in at least one time point among 3 hr, 6 hr, and 24 hr. Several genes involved in fibrogenesis regulation. Several types of pro-collagens (Col1a2, Col5a2, Col6a3, and Col13a1) and tissue inhibitor of metal-loproteinase1 (TIMP1) were up regulated during all the time points. Genes related to growth factors, chemokines, and oxidative stress, which were known to control fibrogenesis, were significantly changed. In addition, $GdCl_{3}$ induced abnormal regulation between lipid synthesis and degradation related genes. These data will provide the information about influence of $GdCl_{3}$ to hepatotoxicity.

Cotinine Inhibits Catecholamine Release Evoked by Cholinergic Stimulation from the Rat Adrenal Medulla

  • Koh, Young-Yeop;Jang, Seok-Jeong;Lim, Dong-Yoon
    • Archives of Pharmacal Research
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    • v.26 no.9
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    • pp.747-755
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    • 2003
  • The aim of the present study was to clarify whether cotinine affects the release of catecholamines (CA) from the isolated perfused rat adrenal gland, and to establish the mechanism of its action, in comparison with the response of nicotine. Cotinine (0.3∼3 mM), when perfused into an adrenal vein for 60 min, inhibited CA secretory responses evoked by ACh (5.32 mM), DMPP (a selective neuronal nicotinic agonist, 100 $\mu$M for 2 min) and McN-A-343 (a selective muscarinic $M_1 -agonist, 100 \mu$ M for 2 min) in dose- and time-dependent manners. However, cotinine did not affect CA secretion by high $K^+$ (56 mM). Cotinine itself also failed to affect basal CA output. Furthermore, in the presence of cotinine (1 mM), CA secretory responses evoked by Bay-K-8644 (an activator of L-type $Ca^{2+}$ channels, 10 $\mu$ M) and cyclopiazonic acid (an inhibitor of cytoplasmic $Ca^{2+}-ATPase, 10 \mu$ M) were relative time-dependently attenuated. However, nicotine (30$\mu$ M), given into the adrenal gland for 60 min, initially rather enhanced CA secretory responses evoked by ACh and high $K^+$, followed by the inhibition later, while it time-dependently depressed the CA release evoked by McN-A-343 and DMPP. Taken together, these results suggest that cotinine inhibits greatly CA secretion evoked by stimulation of cholinergic (both nicotinic and muscarinic) receptors, but does fail to affect that by the direct membrane-depolarization. It seems that this inhibitory effect of cotinine may be exerted by the cholinergic blockade, which is associated with blocking both the calcium influx into the rat adrenal medullary chromaffin cells and $Ca^{2+}$ release from the cytoplasmic calcium store. It also seems that there is a big difference in the mode of action between cotinine and nicotine in the rat adrenomedullary CA secretion.