• YAKHAK HOEJI
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• v.56 no.6
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• pp.347-351
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• 2012

5-Lipoxygenase (5-LO) catalyzes the formation of two major groups of leukotrienes, LTB4 and cysteinyl leukotrienes (CysLT), and it has been implicated as a promising drug target to treat various inflammatory diseases. Since its role in mature osteoclasts (mOCs) had not been reported, we investigated the effect of 5-LO inhibitors on mOCs. We showed that 5-LO inhibitors dose-dependently decreases the number of mOCs. The effects of 5-LO inhibitors were reversible, suggesting that they did not cause any cellular damages in mOCs. We further demonstrated that the suppression of mOCs by 5-LO inhibitors was caused mainly by disruption of the actin ring formation. Similar effects were shown with CysLT receptor (CysLTR)1 antagonist in mOCs. The mRNA expression of CysLTR1 and the production of CysLT were increased in mOCs. These results indicate that CysLTR1 mediates the suppression of mOCs by 5-LO inhibitors. Taken together, this study demonstrated that 5-LO plays important role in mOCs and possibly a novel therapeutic target for bone resorption diseases.

• Journal of Internet Computing and Services
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• v.19 no.5
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• pp.97-105
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• 2018

In this paper, we present our recent effort on the development of a portable OCS system (SCH-mOCS), which provides minimal but essential functionalities of conventional OCS systems. SCH-mOCS is targeted for the environment where Internet connection is not available and fast processing of essential patient information is needed. The main usage could be found at the outdoor environment, such as voluntary medical services at challenged regions. The target of the first usage of the system is in the rural area of Cambodia where medical service and ICT infrastructure is poor. We have been conducting voluntary medical services for 15 years in Cambodia, where the services usually run for 3 days and include outpatient diagnosis/consultation, medication, and simple surgeries. This medical service started in 2002, where about 20 SoonChunHyang University Bucheon Hospital staffs (doctors, nurses, and pharmacists) participated. We realized that a system like SCH-mOCS is needed: we have to consult many patients in a short period, so that a prompt response and prescription to the patients are very important. However, the conventional OCS system is not suitable, because the service is usually conducted outdoor environment where Internet connected computers cannot be installed. Moreover, since the service needs only a subset of the conventional hospital information system and fast system response, application of a full OCS is not practical. The adequate system is a bare minimal OCS system, with very simple and quickly manageable patient admission, consultation, and prescription functionalities. In this paper, we describe hardware as well as the software aspect of a mini-OCS we have developed for the purpose. We named the system SCH-mOCS (SoonChunHyang mini-OCS). We also describe the usage scenario of SCH-mOCS in order to demonstrate that the system is general enough to apply for other similarly challenged regions.

• BMB Reports
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• v.45 no.5
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• pp.281-286
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• 2012

Osteoclasts are multinucleated cells that are formed by the fusion of pre-fusion osteoclasts (pOCs). The fusion of pOCs is known to be important for osteoclastic bone resorption. Here, we examined the effect of IFN-${\gamma}$ on the fusion of pOCs. IFN-${\gamma}$ greatly increased the fusion of pOCs in a dose-dependent manner. Furthermore, IFN-${\gamma}$ induced pOC fusion even in hydroxyapatite-coated plates used as a substitute for bone. The resorption area of pOCs stimulated with IFN-${\gamma}$ was significantly higher than that of the control cells. IFN-${\gamma}$ induced the expression of dendritic cell-specific transmembrane protein (DC-STAMP), which is responsible for the fusion of pOCs. IFN-${\gamma}$ enhanced DC-STAMP expression in a dose-dependent manner. The mRNA expression of c-Fos and nuclear factor of activated T cells (NFAT) c1 was enhanced in the pOCs treated with IFN-${\gamma}$. Taken together, these results provide a new insight into the novel role of IFN-${\gamma}$ on the fusion of pOCs.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2004.05a
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• pp.157-160
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• 2004

We have studied an optically compensated splay (OCS) mode driven by fringe electric field. The OCS LC configuration obtained by applying voltage to vertically aligned LCs shows a dark state when an optic axis of the OCS cell coincides with one of crossed polarizer axis. When the fringe electric field is applied, the LC director rotates in plane above whole electrode surface, giving rise to high transmittance and wide viewing angle simultaneously.

• Korean Journal of Animal Reproduction
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• v.25 no.2
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• pp.191-198
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• 2001

The purpose of this study was to investigate the effects of embryo sources such as in vivo vs. in vitro produced blastocyst, and culture systems on the membrane permeability and viability of bovine blastocyst following GMP vitrification. To produce in vivo embryos, six cows were superovulated by administration of follicle stimulation hormone (FSH) and prostaglandin $F_{2{\alpha}}$(PG $F_{2{\alpha}}$). in vitro embryos were produced by two different culture systems, oviduct co-culture (OCS) and defined culture system (HECM-6; DCS). Ovaries were picked up at a local slaughterhouse and transported to laboratory in 3$0^{\circ}C$ saline within 2 h. Ovaries were washed with same saline three times and then placed in saline on warm plate adjusted at 3$0^{\circ}C$ during aspiration. The blastocysts produced were assigned for membrane permeability and viability following GMP vitrification. The membrane permeability of blastocysts was checked in 0.5 M sucrose solution on warm plate at 35$^{\circ}C$ for 0, 2, 5 and 7 min, respectively. Then the diameters (width and length) of embryo cytoplasms were measured by a eyepiece meter, and they were converted to their volume by 4/3 $\pi$ $r^3$. The blastocysts were cryopreserved by GMP vitrification method, where they were sequentially placed into vitrification solution before being loaded into GMP vessels and immersed into L$N_2$ within 20 to 25 sec. Post-thaw blastocysts were serially washed in 0.25 and 0.15 M sucrose in HM and TCM-199 for 5 min each, and then cultured in TCM 199 supplemented with 10% FCS for 24 or 48 h. The volume change of in vivo blastocyst at 0, 2, 5 and 7 min (100, 37.1, 34.3 and 31.6%) was significantly more shrunk than those of in vitro blastocysts derived from OCS (100, 59.8, 48.9, 47.9%) and DCS (100, 57.2, 47.3 and 46.9%) (P＜0.05). The viability of post-thaw blastocyst derived from in vivo (93.6%) was also significantly different from those in OCS and DCS (81.9 and 83.6%; P＜0.05). In the present culture system, the morphology of embryos produced in vitro was similar to that of in vivo embryos, but the quality in membrane permeability and post-thaw viability showed a big difference from their sources as in vivo or in vitro derived from OCS and DCS. The results indicated that the quality of in vivo embryos in membrane permeability and post-thaw viability was better than those of in vitro embryos derived from OCS or DCS.

• 한국정보디스플레이학회:학술대회논문집
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• 2004.08a
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• pp.1197-1199
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• 2004

We have studied an optically compensated splay (OCS) mode driven by fringe electric field. The OCS configuration obtained by applying voltage to vertically aligned LCs shows a dark state when an optic axis of the OCS cell coincides with one of crossed polarizer axis. When the fringe electric field is applied, the LC director rotates in plane above whole electrode surface, giving rise to the high transmittance, the low operating voltage and wide viewing angle simultaneously.

• International Journal of Naval Architecture and Ocean Engineering
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• v.6 no.4
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• pp.775-787
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• 2014

Availabilities of subsea Blowout Preventers (BOP) in the Gulf of Mexico Outer Continental Shelf (GoM OCS) is investigated using a Markov method. An updated ${\beta}$ factor model by SINTEF is used for common-cause failures in multiple redundant systems. Coefficient values of failure rates for the Markov model are derived using the ${\beta}$ factor model of the PDS (reliability of computer-based safety systems, Norwegian acronym) method. The blind shear ram preventer system of the subsea BOP components considers a demand rate to reflect reality more. Markov models considering the demand rate for one or two components are introduced. Two data sets are compared at the GoM OCS. The results show that three or four pipe ram preventers give similar availabilities, but redundant blind shear ram preventers or annular preventers enhance the availability of the subsea BOP. Also control systems (PODs) and connectors are contributable components to improve the availability of the subsea BOPs based on sensitivity analysis.

• Journal of Electrochemical Science and Technology
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• v.13 no.2
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• pp.308-320
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• 2022

The high internal resistance (R_int) that develops across the sediment microbial fuel cells (SMFC) limits their power production (~4/10 mW m^-2) that can be recovered from an initial oil-contaminated sediment (OCS). In the anolyte, R_int is related to poor biodegradation activity, quality and quantity of contaminant content in the sediment and anode material. While on the catholyte, R_int depends on the properties of the catholyte, the oxygen reduction reaction (ORR), and the cathode material. In this work, the main factors limiting the power output of the SMFC have been minimized. The power output of the SMFC was increased (47 times from its initial value, ~4 mW m^-2) minimizing the SMFC R_int (28 times from its initial value, 5000 ohms), following the main modifications. Anolyte: the initial OCS was amended with several amounts of gasoline and kerosene. The best anaerobic microbial activity of indigenous populations was better adapted (without more culture media) to 3 g of kerosene. Catholyte: ORR was catalyzed in birnessite/carbon fabric (CF)-cathode at pH 2, 0.8M Na₂SO₄. At the class level, the main microbial groups (Gammaproteobacteria, Coriobacteriia, Actinobacteria, Alphaproteobacteria) with electroactive members were found at C-anode and were associated with the high-power densities obtained. Gasoline is more difficult to biodegrade than kerosene. However, in both cases, SMFC biodegradation activity and power output are increased when ORR is performed on birnessite/CF in 0.8 M Na₂SO₄ at pH 2. The work discussed here can focus on bioremediation (in heavy OCS) or energy production in future work.

• Journal of Dental Anesthesia and Pain Medicine
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• v.18 no.1
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• pp.9-17
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• 2018

Background: The structure and function of bone tissue is maintained through a constant remodeling process, which is maintained by the balance between osteoblasts and osteoclasts. The failure of bone remodeling can lead to pathological conditions of bone structure and function. Remifentanil is currently used as a narcotic analgesic agent in general anesthesia and sedation. However, the effect of remifentanil on osteoclasts has not been studied. Therefore, we investigated the effect of remifentanil on pre-osteoclast (pre-OCs) differentiation and the mechanism of osteoclast differentiation in the absence of specific stimulus. Methods: Pre-OCs were obtained by culturing bone marrow-derived macrophages (BMMs) in osteoclastogenic medium for 2 days and then treated with various concentration of remifentanil. The mRNA expression of NFATc1 and c-fos was examined by using real-time PCR. We also examined the effect of remifentanil on the osteoclast-specific genes TRAP, cathepsin K, calcitonin receptor, and DC-STAMP. Finally, we examined the influence of remifentanil on the migration of pre-OCs by using the Boyden chamber assay. Results: Remifentanil increased pre-OC differentiation and osteoclast size, but did not affect the mRNA expression of NFATc1 and c-fos or significantly affect the expression of TRAP, cathepsin K, calcitonin receptor, and DC-STAMP. However, remifentanil increased the migration of pre-OCs. Conclusions: This study suggested that remifentanil promotes the differentiation of pre-OCs and induces maturation, such as increasing osteoclast size. In addition, the increase in osteoclast size was mediated by the enhancement of pre-OC migration and cell fusion.

• Archives of Pharmacal Research
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• v.28 no.3
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• pp.330-334
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• 2005

The effect of a new hepatoprotective agent, YH-439, on the hepatobiliary transport of a model organic cation (OC), TBuMA (tributylmethylammonium), was investigated. The area under the plasma concentration-time curve (AUC) from time zero to 4 h following iv administration of TBuMA (6.6 $\mu$mol/kg) was increased significantly when YH-439 in corn oil (300 mg/kg) was orally administered to rats 24 h prior to the experiment. Nevertheless, the cumulative biliary excretion of TBuMA remained unchanged. As a consequence, the apparent biliary clearance ($CL_b$) of TBuMA was decreased significantly as a result of YH-439 pretreatment, consistent with the fact that the in vivo excretion clearance of TBuMA across the canalicular membrane ($CL_{exc}$) was not changed by the pretreatment. The in vitro uptake of TBuMA into isolated hepatocytes was decreased by one half by the pretreatment, owing to a decrease in the apparent V$_{max}$ and $CL_{linear}$, but the $K_m$ for the process remained constant. Most interestingly, however, the sinusoidal uptake of glucose, a nutrient, into hepatocytes was not influenced by the pretreatment, suggesting the YH-439 pretreatment specifically impaired the sinusoidal uptake of OCs. Thus, the OC-specific inhibition of hepatic uptake, without influencing the uptake of glucose, a nutrient, appeared to be associated with the hepatoprotective activity of YH-439.