• Journal of Microbiology and Biotechnology
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• v.18 no.6
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• pp.1170-1178
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• 2008

The cyclopentenone prostaglandins (cyPGs) prostaglandin $A_1$ ($PGA_1$) and 15-deoxy-${\Delta}^{12,14}$-prostaglandin $J_2$ (15d-$PGJ_2$) have been reported to exhibit antiinflammatory activity in activated monocytes/macrophages. However, the effects of these two cyPGs on the expression of cytokine genes may differ. In this study, we investigated the mechanism of action of $PGA_1$ in lipopolysaccharide (LPS)-induced expression of inter leu kin (IL)-10 mRNA in mouse peritoneal macrophages. 15d-$PGJ_2$ inhibited expression of LPS-induced IL-10, whereas $PGA_1$ increased LPS-induced IL-10 expression. This synergistic effect of $PGA_1$ on LPS-induced IL-10 expression reached a maximum as early as 2 h after simultaneous $PGA_1$ and LPS treatment ($PGA_1$/LPS), and did not require new protein synthesis. The synergistic effect of $PGA_1$ was inhibited by GW9662, a specific peroxisome proliferator-activated receptor ${\gamma}(PPAR{\gamma})$ antagonist, and Bay-11-7082, a NF-${\kappa}B$ inhibitor. The extracellular signal-regulated kinases (ERK) inhibitor PD98059 increased the expression of $PGA_1$/LPS-induced IL-10 mRNA, rather than inhibiting the IL-10 expression. Moreover, $PGA_1$ inhibited LPS-induced ERK phosphorylation. The synergistic effect of $PGA_1$ on LPS-induced IL-10 mRNA and protein production was inhibited by p38 inhibitor PD169316, and $PGA_1$ increased LPS-induced p38 phosphorylation. In the case of stress-activated protein kinase/c-Jun $NH_2$-terminal kinase (SAPK/JNK), the SAPK/JNK inhibitor SP600125 did not inhibit IL-10 mRNA synthesis but inhibited the production of IL-10 protein remarkably. These results suggest that the synergistic effect of $PGA_1$ on LPS-induced IL-10 expression is NF-${\kappa}B$-dependent and mediated by mitogen-activated protein (MAP) kinases, p38, and SAPK/JNK signaling pathways, and also associated with the $PPAR{\gamma}$ pathway. Our data may provide more insight into the diverse mechanisms of $PGA_1$ effects on the expression of cytokine genes.

• The Korean Journal of Pharmacology
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• v.27 no.2
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• pp.191-196
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• 1991

The present study was performed to determine whether estradiol, via cAMP mediation, induces prostaglandin synthesis by modulating phospholipase $A_2$ activity which hydrolyzes phospholipids into arachidonic acids, a precursor for prostaglandin synthesis, during the implantation process in rats. Uterine phospholipase $A_2$ activity was elevated on day 5 of pregnancy when implantation normally occurs in rats. Moreover, phospholipase $A_2$ activity was higher in the implant sites than in the non-implant sites of uterus on day 6. In delayed implantation model, phospholipase $A_2$ activity was increased at 12 hrs after estradiol administration and at 8 hrs after dbcAMP administration. In addition, higher activity of phospholipase $A_2$ was induced by the treatment of estradiol plus theophylline, compared with estradiol-only treated group. The simultaneous treatment of indomethacin with estradiol or dbcAMP did not alter phospholipase $A_2$ activity compared with estradiol or dbcAMP-only treated group although significant suppression was observed in uterine PGE and $PGF_{2{\alpha}}$ concentrations. These results suggest that estradiol or cAMP stimulates uterine phospholipase $A_2$ activity, thereby increasing prostaglandin synthesis during the implantation process in rats.

• Journal of the Korean Society of Food Culture
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• v.5 no.4
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• pp.443-448
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• 1990

The object of this study was to investigate the characteristics of pectinesterase(PE), polygalacturonase(PG) and Peroxidase(POD) in Kimchi materials. The results were as follows : 1. The specific activities of PEs in Korean cabbage, Korean raddish, garlic and ginger were 200 unit/mg protein, 23.1 unit/mg protein, 0.8 unit/mg protein and 32 unit/mg protein, respectively. The optimum pHs of PEs in all materials were between 7 to 8. The concentrations of NaCl, $CaCl_2$ which showed the highest activities of PEs were $0.2{\sim}0.3M$ NaCl, 50 mM $CaCl_2$ in Korean cabbage and raddish, 0.05 M NaCl, 20 mM $CaCl_2$ in garlic and 0.2 M NaCl, 20 mM $CaCl_2$ in ginger. 2. The specific activities and the optimum pHs of PGs were 1.5 unit/mg protein and pH 4.5 in Korean cabbage, 1.6 unit/mg protein and $pH\;4.5{\sim}5.5M$ in Korean raddish, 0.06 unit/mg protein and $pH\;3.0{\sim}3.5M$ in garlic, and 0.06 unit/mg protein and $CaCl_2$ in ginger. The concentrations of NaCl, $CaCl_2$ which showed the highest activities of PGs were $0.1{\sim}0.2M$ NaCl and $0.15{\sim}0.2mM$ mM $CaCl_2$ in all materials. 3. The specific activities and the optimum pHs of PODs in Korean cabbage, Korean raddish, garlic and ginger were 71.3 unit/mg protein ; pH 6.0. 769 unit/mg protein ; pH 5.5, 1.09 unit/mg protein ; pH 4.5 and 12.7 unit/mg protein ; $pH\;5.0{\sim}5.5M$, respectively. POD activities were not decreased in Korean cabbage, but decreased in Korean raddish by the increase of NaCl, $CaCl_2$ concentrations. In garlic and ginger, POD activities were a little slightly affected by the increase of NaCl, $CaCl_2$ concentrations.

• Molecules and Cells
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• v.20 no.2
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• pp.235-240
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• 2005

Extracts of pine needles (Pinus densiflora Sieb. et Zucc.) have diverse physiological and pharmacological actions. In this study we show that pine needle extract alters pacemaker currents in interstitial cells of Cajal (ICC) by modulating ATP-sensitive $K^+$ channels and that this effect is mediated by prostaglandins. In whole cell patches at $30^{\circ}C$, ICC generated spontaneous pacemaker potentials in the current clamp mode (I = 0), and inward currents (pacemaker currents) in the voltage clamp mode at a holding potential of -70 mV. Pine needle extract hyperpolarized the membrane potential, and in voltage clamp mode decreased both the frequency and amplitude of the pacemaker currents, and increased the resting currents in the outward direction. It also inhibited the pacemaker currents in a dose-dependent manner. Because the effects of pine needle extract on pacemaker currents were the same as those of pinacidil (an ATP-sensitive $K^+$ channel opener) we tested the effect of glibenclamide (an ATP-sensitive $K^+$ channels blocker) on ICC exposed to pine needle extract. The effects of pine needle extract on pacemaker currents were blocked by glibenclamide. To see whether production of prostaglandins (PGs) is involved in the inhibitory effect of pine needle extract on pacemaker currents, we tested the effects of naproxen, a non-selective cyclooxygenase (COX-1 and COX-2) inhibitor, and AH6809, a prostaglandin EP1 and EP2 receptor antagonist. Naproxen and AH6809 blocked the inhibitory effects of pine needle extract on ICC. These results indicate that pine needle extract inhibits the pacemaker currents of ICC by activating ATP-sensitive $K^+$ channels via the production of PGs.

• Clinical and Experimental Reproductive Medicine
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• v.25 no.1
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• pp.25-33
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• 1998

Cyclooxygenase (COX) is an enzyme involved in the conversion of arachidonic acid to prostaglandins (PGs), and exists in two forms, COX-1 and COX-2. COX has been reported to be involved in early implantation by secretion of PGs which causes permeability of vessels and reaction of decidual cells around the implantation site. Recently, in mice and sheep studies, COX-1 and COX-2 expression in the endometrium has been reported to be different according to implantation and stages of the estrous cycle, but expression of COX-1 and COX-2 in human endometrium during the menstrual cycle has not yet been established. The purpose of this study was to observe the variances of COX-1 and COX-2 expression by immunohistochemical staining in endometrial samples obtained from human hysterectomy specimens and biopsies of women of reproductive age according to different stages of the menstrual cycle. Also, we attempted to observe COX-1 and COX-2 expression in the epithelial and stromal cells of the endometrium obtained during the mid-secretory phase, which were cultured separately. COX-2 showed a cyclic pattern of expression according to the different stages of the menstrual cycle and was strongly expressed particularly at the mid-secretory phase which corresponds to the time of implantation. However, COX-1 tended to be increased in the early proliferative, and mid- and late secretory phases, but was also expressed in the whole menstrual cycle showing no particular pattern. In the separately cultured cells COX-1 was expressed in epithilial cells and COX-2 in the stromal cells. The above results suggest that since COX-2 is expressed at the same time as implantation and cultured cells display a specific secretory pattern, COX-2 has inductive endocrine enzyme properties and has an important effect on endometrial cells during implantation. Also, COX-2 expression in endometrial cells may be utilized as a useful marker of endometrial maturation.

• Korean journal of applied entomology
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• v.61 no.1
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• pp.173-195
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• 2022

Like vertebrates, insects synthesize various eicosanoids after the committed catalytic step of phospholipase A₂ (PLA₂). However, the subsequent biosynthetic steps exhibit some deviation from those of vertebrates. Due to little composition of arachidonic acid in insect phospholipids, PLA₂ releases linoleic acid, which is another polyunsaturated fatty acid and relatively rich in insect phospholipids, to synthesize arachidonic acid via chain extension and desaturation. Resulting arachidonic acid is then oxygenated into a prostaglandin (PG), PGH₂, by a specific peroxidase called peroxynectin, but not by cyclooxygenase. PGH₂ is then isomerized to various PGs such as PGA₂, PGD₂, PGE₂, PGI₂, and a thromboxane (TXB₂). All four epoxyeicosatrienoic acids such as 5,6-EET, 8,9-EET, 11,12-EET, and 14,15-EET are also synthesized from arachidonic acid by oxygenation of vertebrate types of monooxygenases. However, the other type of eicosanoids called leukotrienes are found in insect tissues but their synthetic pathway is unclear. Eicosanoids mediate various insect physiological processes such as metabolism, excretion, immunity, and reproduction. Thus, identification of novel compounds interrupting eicosanoid biosynthesis would be a novel approach to develop insecticides. This review focuses on PGs and their immune mediation.

• Journal of the Korean Society of Marine Environment & Safety
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• v.28 no.spc
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• pp.11-17
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• 2022

In this study, we address the development of a floating platform system based on a unmanned surface vessel for wide-area sensing and monitoring of hazardous and noxious substances (HNSs). For long endurance, a movable floating platform with no mooring lines was used and modified for HNS sensing and monitoring. The floating platform was equipped with various sensors such as optical and thermal imaging cameras, marine radar, and sensors for detecting HNSs in water and air. Additionally, for experiment validation in real outdoor environments, a portable gas-exposure system (PGS) was built and installed on the monitoring system. The software for carrying out the mission was integrated with the Robot Operating System (ROS) framework. The practical feasibility of the developed system was verified through experimental tests conducted in inland water and real-sea environments.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.39 no.12
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• pp.559-565
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• 2002

Today, because a quality factor of the inductor fabricated on silicon substrate for RFIC is under 12, the realization of inductor haying high-Q is essential. In this paper, two inductors having improved Q-factor are proposed and fabricated using a bondwire on silicon substrate. Also for the PGS is applied to the same inductors, four inductors are fabricated finally The bondwire Inductors have the relatively low conductor loss due to wide cross-section area and they can reduce the parastic capacitance very much because they are located in the air. Simulation and measurement results show that the proposed inductors have much more improved Q-factor, 15, than a conventional spiral inductor at 1.5 GHz. Because of the use of an automatic bonding machine, we can fabricate the high - Q inductors very easily, repeatedly.

• BMB Reports
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• v.42 no.7
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• pp.401-410
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• 2009

We have developed a targeted lipidomics approach that makes it possible to directly analyze chiral eicosanoid lipids generated in cellular systems. The eicosanoids, including prostaglandins (PGs), thromboxanes (TXs), leukotrienes (LTs) and alcohols (HETEs), have been implicated as potent lipid mediators of various biological processes. Enzymatic formations of eicosanoids are regioselective and enantioselective, whereas reactive oxygen species (ROS)-mediated formation proceeds with no stereo-selectivity. To distinguish between enzymatic and non-enzymatic pathways of eicosanoid formation, it is necessary to resolve enantiomeric forms as well as regioisomers. High sensitivity is also required to analyze the eicosanoid lipids that are usually present as trace amounts (pM level) in biological fluids. A discovery of liquid chromatography-electron capture atmospheric pressure chemical ionization/mass spectrometry (LC-ECAPCI/MS) allows us to couple normal phase chiral chromatography without loss of sensitivity. Analytical specificity was obtained by the use of collision-induced dissociation (CID) and tandem MS (MS/MS). With combination of stable isotope dilution methodology, complex mixtures of regioisomeric and enantiomeric eicosanoids have been resolved and quantified in biological samples with high sensitivity and specificity. Targeted chiral lipidomics profiles of bioactive eicosanoid lipids obtained from various cell systems and their biological implications have been discussed.

• Korean Journal of Pharmacognosy
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• v.32 no.4 s.127
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• pp.311-315
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• 2001

The root of Astragalus membranaceus Bunge (Leguminosae), which has been used for the treatment of hypertension, chronic hepatitis, duodenal ulcers, chronic nephritis and promotion of immunity in folk remedies. Cyclooxygenase (COX-2) is responsible for the production of large amounts of proinflammatory prostaglandins (PGs) at the inflammatory site. Thus, a logical approach to the treatment of inflammatory disease should involve the inhibitors of COX-2. To develop new COX-2 inhibitors from natural products, Astragali Radix was screened by inhibiting prostaglandin $E_2(PGE_2)$ generation in the culture medium using enzyme immunometric assay. Two isoflavone glycosides, $7,2'-dihydroxy-3',4'-dimethoxyisoflavan-7-O-{\beta}-D-glucoside$ and $calycosin-7-O-{\beta}-D-glucoside$ isolated from Astragali Radix inhibited COX-2 activity.