• The Korean Journal of Pharmacology
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• v.31 no.3
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• pp.291-297
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• 1995

The objectives of this study is to compare the inhibitory mechanism of sodium nitroprusside and forskolin on the phorbol ester, activator of protein kinase C (PKC), -induced contractions in rat aorta. $0.1\;{\mu}M$ phorbol dibutyrate (PDBu) induced sustained contractions and increased phosphorylations of myosin light chain (MLC) time-dependently. At 30 min, the contractions and phosphorylations of MLC by PDBu were augmented maximally and remained constant. Moreover, $^{45}Ca^{2+}$ uptake was increased 30 min after PDBu stimulation from resting values. Sodium nitroprusside which activates guanylyl cyclase followed by increasing cGMP, inhibited the PDBu-induced contractions concentration-dependently. On the other hand, forskolin which activates adenylyl cyclase followed by increasing cAMP, also inhibited the PDBu-induced contractions concentration-dependently. However, sodium nitroprusside was more potent to inhibition of the PDBu-induced contractions than forskolin. Sodium nitroprusside inhibited $^{45}Ca^{2+}$ uptake by PDBu stimulation. Forskolin also inhibited $^{45}Ca^{2+}$ uptake by PDBu stimulation. Sodium nitroprusside and forskolin inhibited the phosphorylations of MLC by PDBu, respectively. However, sodium nitroprusside was more potent to inhibition of phosphorylations of MLC by PDBu than forskolin. From these results, Sodium nitroprusside via cGMP or forskilin via cAMP may reduce myoplasmic $Ca^{2+}$ followed by suppression of phosphorylations of MLC of PKC-mediated contractions, which results in vasodilation. However, cGMP may play a role more importantly than cAMP on the regulation of protein kinase C-mediated contraction in vascular smooth muscle.

• Progress in Medical Physics
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• v.13 no.2
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• pp.62-68
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• 2002

A muiltileaf collimator (MLC) is used as a replacement for conventional blocks. The MLC, however may not be appropriate for a fine field shaping. For the fine field shaping, conventional block can be added under the MLC. But it may significantly affect on the dosimetric characteristics such as surface dose of skin, buildup region and percent depth doses. We performed the study to evaluate the surface dose and the maximum depth dose using MLC conjunction with conventional blocks for various field sizes and energies. We confirmed the surface dose was increased by using the additional conventional block under the MLC ranging from 10 to 35.6％ according to various field sizes and radiation beam energies. The surface dose was effectively reduced by application of 2 or 3 m thickness of lead plate as electron filter.

• Korean Journal of Food Science and Technology
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• v.29 no.3
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• pp.400-406
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• 1997

Chemical composition and antimicrobial activity of Houttuynia cordata Thunb. were investigated to develop a natural food preservative from it. Aspartic acid, glutamic acid, glycine and arginine were major amino acids of Houttuynia cordata Thunb., but were present in a trace amount. Free sugars were composed of glucose, fructose, sucrose and maltose and major fatty acids were linolenic acid, linoleic acid, oleic acid, and palmitic acid. Mineral elements were potassium, calcium, magnesium, iron, zinc, and copper. Antimicrobial activities were shown in acidic, neutral and phenolic fraction of Houttuynia cordata Thunb., but not in basic fraction. Among the four fractions, neutral fraction showed the strongest antimicrobial activities against microorganisms tested, such as Pseudomnas aeruginosa, Micrococcus luteus, Bacillus subtilis, Aspergillus parasiticus and Aspergillus flavus. Minimum inhibitory concentration (MIC) and minimum lethal concentration (MLC) of the neutral fraction varied according to microoganisms tested. The lowest values of MIC (0.0075 g eq./mL) and MLC (0.10 g eq./mL) were obtained from Pseudomonas aeruginosa.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.36 no.3
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• pp.225-229
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• 2003

Plant ash and soil drainage, derived by frequent mountain fires during winter, might cause biological contamination to seaweeds at seashore and river mouse area. To thalli of Ulva pertusa, maximum non-lethal concentration(MNLC), lethal concentration 50 $(LC_{50})$ and minimum lethal concentration (MLC) of pine needle ash were shown as 60, 350 and 550 mg/mL, respectively. The yellow loess and granite sand did not damage at concentrations of 20 and 200 mg/mL, respectively To thalli of Porphyra yezoensis, the MNLC, LC5O, MLC of pine needle ash were shown as 0.08, 0.4 and 1.0 mg/mL, respectively. Effects of yellow loess and granite sand were approximately 1/2 and 1/10 of the ash. To thalli of Undaria pinnatifida, the pine needle ash, yellow loess and granite sand did not damage at the concentration range of 20 to 40 mg/mL. Change of pigments $(chlorophyll\;\alpha,\;lutein,\;\beta-carotene,\;phycoerthrin)$ was also determined at the MNLC, $LC-{50}$ and MLC of pine needle ash. Among three seaweeds tested, P. yezoensis produced the most 2.7-fold of lutein and 2.3-fold of $\beta-carotene$ at $LC-{50}$ of the ash. Thus the P. yezoensis, appeared as a sensitive indicator, could be used as one of test organisms for determination of the biological effect of pollutants contaminated in marine environment.

• Progress in Medical Physics
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• v.26 no.3
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• pp.168-177
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• 2015

For evaluating the treatment planning accurately, the quality assurance for treatment planning is recommended when patients were treated with IMRT which is complex and delicate. To realize this purpose, treatment plan quality assurance software can be used to verify the delivered dose accurately before and after of treatment. The purpose of this study is to evaluate the accuracy of treatment plan quality assurance software for each IMRT plan according to MLC DLG (dosimetric leaf gap). Novalis Tx with a built-in HD120 MLC was used in this study to acquire the MLC dynalog file be imported in MobiusFx. To establish IMRT plan, Eclipse RTP system was used and target and organ structures (multi-target, mock prostate, mock head/neck, C-shape case) were contoured in I'mRT phantom. To verify the difference of dose distribution according to DLG, MLC dynalog files were imported to MobiusFx software and changed the DLG (0.5, 0.7, 1.0, 1.3, 1.6 mm) values in MobiusFx. For evaluation dose, dose distribution was evaluated by using 3D gamma index for the gamma criteria 3% and distance to agreement 3 mm, and the point dose was acquired by using the CC13 ionization chamber in isocenter of I'mRT phantom. In the result for point dose, the mock head/neck and multi-target had difference about 4% and 3% in DLG 0.5 and 0.7 mm respectively, and the other DLGs had difference less than 3%. The gamma index passing-rate of mock head/neck were below 81% for PTV and cord, and multi-target were below 30% for center and superior target in DLGs 0.5, 0.7 mm, however, inferior target of multi-target case and parotid of mock head/neck case had 100.0% passing rate in all DLGs. The point dose of mock prostate showed difference below 3.0% in all DLGs, however, the passing rate of PTV were below 95% in 0.5, 0.7 mm DLGs, and the other DLGs were above 98%. The rectum and bladder had 100.0% passing rate in all DLGs. As the difference of point dose in C-shape were 3~9% except for 1.3 mm DLG, the passing rate of PTV in 1.0 1.3 mm were 96.7, 93.0% respectively. However, passing rate of the other DLGs were below 86% and core was 100.0% passing rate in all DLGs. In this study, we verified that the accuracy of treatment planning QA system can be affected by DLG values. For precise quality assurance for treatment technique using the MLC motion like IMRT and VMAT, we should use appropriate DLG value in linear accelerator and RTP system.

• The Korean Journal of Physiology and Pharmacology
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• v.22 no.4
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• pp.437-445
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• 2018

${\alpha}$-Iso-cubebene (ICB) is a dibenzocyclooctadiene lignin contained in Schisandra chinensis (SC), a well-known medicinal herb that ameliorates cardiovascular symptoms, but the mechanism responsible for this activity has not been determined. To determine the role played by ICB on the regulation of vascular tone, we investigated the inhibitory effects of ICB on vascular contractile responses by adrenergic ${\alpha}$-receptor agonists. In addition, we investigated the role on myosin light chain (MLC) phosphorylation and cytosolic calcium concentration in vascular smooth muscle cells (VSMC). In aortic rings isolated from C57BL/6J mice, ICB significantly attenuated the contraction induced by phenylephrine (PE) and norepinephrine (NE), whereas ICB had no effects on KCl (60 mM)-induced contraction. In vasculatures precontracted with PE, ICB caused marked relaxation of aortic rings with or without endothelium, suggesting a direct effect on VSMC. In cultured rat VSMC, PE or NE increased MLC phosphorylation and increased cytosolic calcium levels. Both of these effects were significantly suppressed by ICB. In conclusion, our results showed that ICB regulated vascular tone by inhibiting MLC phosphorylation and calcium flux into VSMC, and suggest that ICB has anti-hypertensive properties and therapeutic potential for cardiovascular disorders related to vascular hypertension.

• Natural Product Sciences
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• v.10 no.5
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• pp.217-219
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• 2004

Cissus quadrangularis L. variant I (Family: Vitaceae), the common variant with square stem is widely used for peptic ulcer disorders (PUD) in traditional medicine. Aerial parts were collected during flowering and vegetative seasons and analysed. Aqueous (hot and cold) and solvent extracts (acetone, chloroform and ethanol) were screened for their anti-Helicobacter pylori (Hp) activities. Among them chloroform extract was observed to recover bioactive principles markedly with low minimal inhibitory concentration (MIC) and minimal lethal concentration (MLC). MIC was $30\;{\mu}g$ in both samples and MLC was $35\;{\mu}g$ for vegetative and $30\;{\mu}g$ for flowering seasons, respectively. Extracts from samples collected during flowering season were better than thse of vegetative season.

• Natural Product Sciences
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• v.9 no.1
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• pp.1-3
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• 2003

Hemidesmus indicus var. indicus belonging to the family Asclepiadaceae was screened for its activity against Helicobacter pylori(Hp) human isolates. Flowering and vegetative period samples were analysed. Aqueous (hot and cold) and solvent extracts (acetone, chloroform and methanol) were screened. Among them chloroform extract was observed to recover bioactive principles with low MIC and MLC. MIC was $75\;{\mu}g$ in both seasons and MLC was $100\;{\mu}g$ for vegetative and $75\;{\mu}g$ for flowering periods respectively. Extracts from samples collected during flowering period was better than that of vegetative period.

• Proceedings of the KSRS Conference
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• 1999.11a
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• pp.262-266
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• 1999

Several commercial companies that plan to provide improved panchromatic and/or multi-spectral remote sensor data in the near future are suggesting that merge datasets will be of significant value. This study evaluated the utility of one major merging process-process components analysis and its inverse. The 6 bands of 30$\times$30m Landsat TM data and the 10$\times$l0m SPOT panchromatic data were used to create a new 10$\times$10m merged data file. For the image classification, 6 bands that is 1st, 2nd, 3rd, 4th, 5th and 7th band may be used in conjunction with supervised classification algorithms except band 6. One of the 7 bands is Band 6 that records thermal IR energy and is rarely used because of its coarse spatial resolution (120m) except being employed in thermal mapping. Because SPOT panchromatic has high resolution it makes 10$\times$10m SPOT panchromatic data be used to classify for the detailed classification. SPOT as the Landsat has acquired hundreds of thousands of images in digital format that are commercially available and are used by scientists in different fields. After the merged, the classifications used supervised classification and neural network. The method of the supervised classification is what used parallelepiped and/or minimum distance and MLC(Maximum Likelihood Classification) The back-propagation in the multi-layer perception is one of the neural network. The used method in this paper is MLC(Maximum Likelihood Classification) of the supervised classification and the back-propagation of the neural network. Later in this research SPOT systems and images are compared with these classification. A comparative analysis of the classifications from the TM and merged SPOT/TM datasets will be resulted in some conclusions.

• The Korean Journal of Physiology and Pharmacology
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• v.13 no.3
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• pp.201-207
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• 2009

Our previous study demonstrated that flavone inhibits vascular contractions by decreasing the phosphorylation levelof the myosin phosphatase target subunit (MYPT1). In the present study, we hypothesized that flavone attenuates vascular contractions through the inhibition of the RhoA/Rho kinase pathway. Rat aortic rings were denuded of endothelium, mounted in organ baths, and contracted with either 30 nM U46619 (a thromboxane A2 analogue) or 8.0 mM NaF 30 min after pretreatment with either flavone (100 or 300 $({\mu}M$) or vehicle. We determined the phosphorylation level of the myosin light chain ($MLC_{20}$), the myosin phophatase targeting subunit 1 (MYPT1) and the protein kinase C-potentiated inhibitory protein for heterotrimeric myosin light chain phophatase of 17-kDa (CPI17) by means of Western blot analysis. Flavone inhibited, not only vascular contractions induced by these contractors, but also the levels of $MLC_{20}$ phosphorylation. Furthermore, flavone inhibited the activation of RhoA which had been induced by either U46619 or NaF. Incubation with flavone attenuated U46619 or NaF-induced phosphorylation of $MYPT1^{Thr855}$ and $CPI17^{Thr38}$, the downstream effectors of Rho-kinase. In regards to the $Ca^{2+}$-free solution, flavone inhibited the phosphorylation of $MYPT1^{Thr855}$ and $CPI17^{Thr38}$, as well as vascular contractions induced by U 46619. These results indicate that flavone attenuates vascular contractions, at least in part, through the inhibition of the RhoA/Rho-kinase pathway.