• Archives of Pharmacal Research
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• 제22권1호
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• pp.48-54
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• 1999

These studies were designed to examine the differential effect of nitric oxide (NO) and cGMP on glutamate neurotransmission. In primary cultures of rat cerebellar granule cells, the glutamate receptor agonist N-methyl-D-aspartate (NMDA) stimulates the elevation of intracellular calcium concentration ($[Ca^{2+}]_i$), the release of glutamate, the synthesis of NO and an increase of cGMP. Although NO has been shown to stimulate guanylyl cyclase, it is unclear yet whether NO alters the NMDA-induced glutamate release and ${[Ca^{2+}]}_i$ elevation. We showed that the NO synthase inhibitor, NG-monomethyl-L-arginine (NMMA), partially prevented the NMDA-induced release of glutamate and elevation of ${[Ca^{2+}]}_i$ and completely blocked the elevation of cGMP. These effects of NO on glutamate release and [Ca2+]i elevation were unlikely to be secondary to cGMP as the cGMP analogue, dibutyryl cGMP (dBcGMP), did not suppress the effects of NMDA. Rather, dBcGMP slightly augmented the NMDA-induced elevation of ${[Ca^{2+}]}_i$ with no change in the basal level of glutamate or ${[Ca^{2+}]}_i$. The extracellular NO scavenger hydroxocobalamine prevented the NMDA-induced release of glutamate providing indirect evidence that the effect of NO may act on the NMDA receptor. These results suggest that low concentration of NO has a role in maintaining the NMDA receptor activation in a cGMP-independent manner.

• 한국산업보건학회지
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• 제11권3호
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• pp.198-205
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• 2001

Many reactive dyes have been used in occupational settings without knowing their toxicity and health hazard information. To investigate the toxicity of reactive dye, C.I.No. Reactive Red 195 was exposed to male and female Sprague Dawley rats by inhalation for 28 days. The rats were exposed C.I.No. Reactive Red 195 for 6 hrs per day and 5days per week. The concentrations for the inhalation exposure were 0, 10, 40 and $160mg/m^3$. After 4 weeks of exposure, rats were examined for exposure related changes through pathology, blood biochemistry and hematology. There were no dose related changes including clinical signs, body weight and relative organ weight changes, hematological and biochemical and histopathological findings. The results indicate that no observed adverse effect level (NOAEL) of 28 days inhalatrion toxicity test for C.I.No. Reactive Red 195 was $160mg/m^3$.

• The Korean Journal of Physiology and Pharmacology
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• 제16권3호
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• pp.211-217
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• 2012

Recent studies have demonstrated that nitric oxide (NO) activates transient receptor potential vanilloid subtype 1 (TRPV1) via S-nitrosylation of the channel protein. NO also modulates various cellular functions via activation of the soluble guanylyl cyclase (sGC)/protein kinase G (PKG) pathway and the direct modification of proteins. Thus, in the present study, we investigated whether NO could indirectly modulate the activity of TRPV1 via a cGMP/PKG-dependent pathway in cultured rat dorsal root ganglion (DRG) neurons. NO donors, sodium nitroprusside (SNP) and S-nitro-N-acetylpenicillamine (SNAP), decreased capsaicin-evoked currents ($I_{cap}$). NO scavengers, hemoglobin and 2-(4-carboxyphenyl)-4,4,5,5-tetramethylimidazoline-1-oxyl-3-oxide (CPTIO), prevented the inhibitory effect of SNP on $I_{cap}$. Membrane-permeable cGMP analogs, 8-bromoguanosine 3', 5'-cyclic monophosphate (8bromo-cGMP) and 8-(4chlorophenylthio)-guanosine 3',5'-cyclic monophosphate (8-pCPT-cGMP), and the guanylyl cyclase stimulator YC-1 mimicked the effect of SNP on $I_{cap}$. The PKG inhibitor KT5823 prevented the inhibition of $I_{cap}$ by SNP. These results suggest that NO can downregulate the function of TRPV1 through activation of the cGMP/PKG pathway in peripheral sensory neurons.

• The Korean Journal of Physiology and Pharmacology
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• 제5권1호
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• pp.93-98
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• 2001

The precise mechanism of set-point regulation in hypothalamus was not elucidated. Nitric oxide synthases(NOS) were detected in hypothalamus, however, the roles of NO in hypothalamus was not fully studied. So, we tested the effects of NO on body temperature because preoptic-anterior hypothalamus was known as the presumptive primary fever-producing site. NO donor sodium nitroprusside (SNP, 4 nmol, i.c.v.) elicited marked febrile response, and this febrile response was completely blocked by indomethacin (a cyclooxygenase inhibitor). But, ODQ (selective guanylate cyclase inhibitor, $50\;{\mu}g,$ i.c.v.) did not inhibit fever induced by SNP. The cyclic GMP analogue dibutyryl-cGMP $(100\;{\mu}g,\;i.c.v.)$ induced significant pyreses, which is blocked by indomethacin. $N^G-nitro-L-arginine$ methyl ester (L-NAME, non selective NOS inhibitor) inhibited fever induced by $interleukin-1{\beta}\;(IL-1{\bata},\;10\;ng,\;i.c.v.),$ one of endogenous pyrogens. These results indicate that NO may have an important role, not related to stimulation of soluble guanylate cyclase, in the signal pathway of thermoregulation in hypothalamus.

• Journal of the Korean Statistical Society
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• 제7권1호
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• pp.61-80
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• 1978

This paper presents general solutions for stochastic square duels with continuous interfiring times and various firing strategies such as standby (S), concentrated (C), seperated (I) and random (R) firings. Analysis of these square duels with negative exponential interfiring times and equivalent values of rates of fire and single shot kill probabilities reveal three important facts: i) Strategy (C) is advantageous against the opponent's strategy (S) and the advantage becomes more pronounced for lower values of single shot kill probabilities. ii) Strategy (I) is always better than strategy (C) no matter which of (C) and (I) the opponent uses and its relative advantege increases to a quarter as single shot kill probabilities increase to one but decreases to zero as they go to zero. iii) However, strategy (I) has no advantage over strategy (C) for small values of single shot kill probabilities. In this paper, square duels with strategies (C) and (I) are based on the assumptions that duelists are homogeneous and both duelists of one side fire simultaneously. The problem of relaxing these assumptions and extension of square ($2 \times 2$) duels to more general ($m \times n) duels are now being investigated.

• 한국식품영양과학회지
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• 제38권12호
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• pp.1685-1690
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• 2009

본 연구에서는 구절초의 항염증 효과를 탐색하기 위해 NO의 함량과 iNOS의 발현 및 PGE2와 COX-2의 발현을 LPS로 염증을 유도한 RAW 264.7 macrophage cell을 이용하여 실험하였다. 연구 결과 구절초 꽃 추출물은 NO 함량을 농도 의존적으로 감소시키는 경향을 나타냈으며 유의한 차이를 보였다. 또한 세포독성은 꽃 추출물(5～50 μg/mL)은 최고 농도인 50 μg/mL에서 약 20%의 독성을 나타냈으며 그 이하의 농도에서는 독성을 나타내지 않았다. NO 생성의 억제는 iNOS의 단백질과 mRNA의 발현을 농도 의존적으로 저해하였으며 유의성 있는 차이를 나타내었다. 이 결과로 구절초 꽃 추출물이 전사단계에서 저해 활성을 나타낸다는 것을 보여주었다. 그러나 PGE2와 COX-2의 발현 억제 효과는 나타나지 않았으며, 이 결과 구절초 꽃 추출물에 의한 COX-2 단백질의 발현 억제와 PGE2 생성 억제는 유의성이 없는 것으로 나타났다. 본 연구 결과, 구절초 추출물은 염증을 일으키는 중요 인자인 NO를 저해하였고, iNOS의 발현, iNOS의 mRNA 발현 등 항염증에 우수한 효과를 보였으며, 항염증 연구의 기초 자료로 활용될 것으로 예상된다. 또한 추후 산업적 응용도 가능하므로 지속적인 연구가 진행되어야 할 것으로 사료된다.

• The Korean Journal of Physiology and Pharmacology
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• 제5권4호
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• pp.343-351
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• 2001

This study was undertaken to investigate the mechanism of lipopolysaccharide (LPS) and nitric oxide (NO) as a regulator of vascular smooth muscle cell (VSMC) proliferation. VSMC was primarily cultured from rat aorta and confirmed by the immunocytochemistry with anti-smooth muscle myosin antibody. The number of viable VSMCs were counted, and lactate dehydrogenase (LDH) activity was measured to assess the degree of cell death. Concentrations of nitrite in the culture medium were measured as an indicator of NO production. LPS was introduced into the medium to induce the inducible nitric oxide synthase (iNOS) in VSMC, and Western blot for iNOS protein and RT-PCR for iNOS mRNA were performed to confirm the presence of iNOS. Inhibitors of iNOS and soluble guanylate cyclase (sGC), sodium nitroprusside (SNP) and L-arginine were employed to observe the action of LPS on the iNOS-NO-cGMP signalling pathway. LPS and SNP decreased number of VSMCs and increased the nitrite concentration in the culture medium, but there was no significant change in LDH activity. A cell permeable cGMP derivative, 8-Bromo-cGMP, decreased the number of VSMCs with no significant change in LDH activity. L-arginine, an NO substrate, alone tended to reduce cell count without affecting nitrite concentration or LDH level. Aminoguanidine, an iNOS specific inhibitor, inhibited LPS-induced reduction of cell numbers and reduced the nitrite concentration in the culture medium. LY 83583, a guanylate cyclase inhibitor, suppressed the inhibitory actions of LPS and SNP on VSMC proliferation. LPS increased amounts of iNOS protein and iNOS mRNA in a concentration-dependent manner. These results suggest that LPS inhibits the VSMC proliferation via production of NO by inducing iNOS gene expression. The cGMP which is produced by subsequent activation of guanylate cyclase would be a major mediator in the inhibitory action of iNOS-NO signalling on VSMC proliferation.

• 대한화학회지
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• 제44권2호
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• pp.127-137
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• 2000

비스(파라-치환페닐)테레프탈산 에스테르의 중앙 테레프탈산 벤젠고리 측면에 데실옥시기가 결합하고 있는 열한개의 새로운 화합물을 합성하였고, 이들의 열적 및 액정 성질을 DSC와 가열판이 부착된 편광현미경을 사용하여 조사하였다. 메소겐의 말단 치환기 X= -H(II-H), -F(II-F), -Cl(Il-Cl), -Br(Il-Br), -I(II-I), -$NO_2(lI-NO_2$), $-CF_3(II-CF_3$), -$OC_2H_5(II-OC_2H_5$), -$OC_4H_9(II-OC_4H_9$), -CN(II-CN) 및 -$C_6H_5(Il-C_6H_5$)로 바꾸었다. $II-OC_2H_5,\;II-OC_4H_9$, 및 $II-C_6H_5$는 단방성 네마틱 액정이었으며, II-H, lI-F, II-Cl, Il-Br, II-I, $II-NO_2$, $II-CF_3$, 및 Il-CN은 액정이 아니었다.

• 한국초전도ㆍ저온공학회논문지
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• 제19권2호
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• pp.48-52
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• 2017

Discrepancy between a power supply current and an actual "spiral" coil current makes the conventional 4-probe measurement of a critical current ($I_c$) of a no-insulation (NI) high temperature superconductor (HTS) coil inaccurate and time-consuming. This paper presents a fast and accurate approach for $I_c$ measurement of NI HTS coils. With an NI HTS coil energized at a constant ramping rate, a complete analytic expression for the spiral coil current was obtained from a first-order partial differential equation that derived from an equivalent circuit model of the NI coil. From the analytic solution, both spiral coil current and radial leak current can be obtained simultaneously, which enables fast and accurate measurement of the NI coil $I_c$. To verify the proposed approach, an NI double-pancake (DP) coil, wound with GdBCO tapes of $6mm{\times}0.1mm$, was constructed and its $I_c$ was repeatedly measured with various ramping rates in a bath of liquid nitrogen at 77 K. The measured results agreed well with the calculated ones, which validates the proposed approach to measure $I_c$ of an NI HTS coil.

• The Korean Journal of Pain
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• 제26권4호
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• pp.374-378
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• 2013

Background: Incisional pain is particularly troublesome after hysterectomy. A method called transversus abdominis plane block (TAPB) has shown promise in managing postoperative pain. In this study, we evaluated the analgesic efficacy of ultrasound-guided TAPB after hysterectomy at different time points and at each time point separately for 48 hours. Methods: Forty-two patients (ASA I, II) who were electively chosen to undergo total abdominal hysterectomy were divided into 2 groups, control (group C) and intervention (group I). Twenty-one patients underwent TAPB (group I) and 21 patients received only the standard treatment with a fentanyl pump (group C). Both groups received standard general anesthesia. For patients in group I, following the surgery and before emergence from anesthesia, 0.5 mg/kg of ropivacaine 0.2% (about 20 cc) was injected bilaterally between the internal oblique and transverse abdominis muscles using sonography. Pain scores using the Visual Analogue Scale (VAS) and drug consumption were measured at 2, 6, 12, 24, and 48 hours after TAPB. Results: There were no significant differences in demographics between the two groups. VAS scores appeared to be lower in group I, although there was no interaction with time when we compared mean VAS measurements at different time points between group I and group C (P > 0.05). The amount of fentanyl flow was consistently higher in group C, but when we compared the two groups at each time point separately, the observed difference was not statistically significant (P < 0.053). The incidence of vomiting was 10% in group I and 28% in group C. There were no complaints of itching, and sedation score was 0 to 3. There were no complications. Conclusions: This study showed that TAPB did not result in a statistically significant decrease in VAS scores at different time points. TAPB did lead to decreased fentanyl flow, but when we compared the two groups at each time point separately, the observed difference was not statistically significant.