• Journal of Physiology & Pathology in Korean Medicine
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• v.31 no.1
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• pp.52-58
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• 2017

This study was aimed to examine relaxing effects of Acanthopanacis cortex(AC) through nitric oxide(NO) production and phosphodiesterase type 5(PDE-5) inhibition in corpus cavernosum. In order to define the relaxation effects of AC extract, rabbit corpus cavernous tissues were prepared in $2{\times}2{\times}8mm$ sized strip. AC extract ($0.01-3.0mg/m{\ell}$) were treated in contracted strips induced by phenylephrine(PE) and $N{\omega}$-nitro-L-arginine (L-NNA) was treated before AC extract-treated. And calcium chloride($Ca^{2+}$) 1 mM was infused into precontracted strips after pretreatment of AC extract in $Ca^{2+}-free$ krebs-ringer solution. When AC extract was applied to human umbilical vein endothelial cell(HUVEC), cell viability was measured by MTT assay, and NO concentration was measured by Griess reagent system. Ratio of smooth muscles to collagen fibers and eNOS, PDE-5 positive reaction were measured by histochemical and immunohistochemical process on mice corpus cavernosum. AC extract significantly affected relaxion of the cavernous strips, and the pretreatment of L-NNA inhibited AC extract-induced relaxation. Contraction induced by the addition of $Ca^{2+}$ was inhibited by treatment with the AC extract in $Ca^{2+}-free$ solution. In AC group, NO concentration, ratio of smooth muscle to collagen fibers, and eNOS positive reaction were increased, PDE-5 positive reaction was decreased compared to PE group. As a result of the above experiment, it was thought that AC extract inhibits the inflow of extracellular $Ca^{2+}$ by activating cGMP through the increase of eNOS / NO and the decrease of PDE-5 which inhibits cGMP activity, in the corpus cavernosum.

• Journal of Life Science
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• v.22 no.2
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• pp.281-284
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• 2012

This study demonstrated that upregulation of gene expression of endoplasmic reticulum (ER) stress chaperones (Bip, ERp29, calnexin, and PDI), ER stress sensors (PERK, ATF6, and Ire1), and cAMP phosphodiesterase 7A1 (cAMP PDE7A1) was induced by ER stresses in FRTL5 cells. While removing A23187 from the culture medium restored upregulation of cAMP PDE7A1 gene expression, removal of thapsigargin did not recover its expression. In addition, cAMP PDE7A1 gene expression was strongly inhibited by treatment with A23187 combined with thyroid stimulating hormone (TSH). The results are the first to show that ER stress induces cAMP PDE7A1 gene expression.

• Journal of Life Science
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• v.27 no.2
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• pp.149-154
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• 2017

Diffuse large B-cell lymphoma (DLBCL) is the most common type of non-hodgkin lymphoma. Advances in the chemotherapeutic treatment of this disease have improved the outcomes of DLBCL; nonetheless, many patients still die of DLBCL, and therefore, a better understanding of this disease and identification of novel therapeutic targets are urgently required. In a recent gene expression profiling study, PDE (phosphodiesterase) 4B was found to be overexpressed in chemotherapy-resistant tumors. The major function of PDE4B is to inactivate the second messenger cyclic 3',5' monophosphate (cAMP) by catalyzing the hydrolysis of cAMP to 5'AMP. It is known that cAMP induces cell cycle arrest and/or apoptosis in B cells, and PDE4B abolishes cAMP's effect on B cells. However, the mechanism by which PDE4B is overexpressed remains unclear. Here, we show that the aberrant expression of miRNA may be associated with the overexpression of this gene. The PDE4B 3' untranslated region (UTR) has three functional binding sites of miR-23b, as confirmed by luciferase reporter assays. Interestingly, miR-23b-binding sites were evolutionarily conserved from humans to lizards, implying the critical role of PDE4B-miR-23b interaction in cellular physiology. The ectopic expression of miR-2 3b repressed PDE4B mRNA levels and enhanced intracellular cAMP concentrations. Additionally, miR-23b expression inhibited cell proliferation and survival of DLBCL cells only in the presence of forskolin, an activator of adenylyl cyclase, suggesting that miR-23b's effect is via the downregulation of PDE4B. These results together suggest that miR-23b could be a therapeutic target for overcoming drug resistance by repressing PDE4B in DLBCL.

• East Asian mathematical journal
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• v.35 no.5
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• pp.547-557
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• 2019

This paper is concerned with the necessary conditions for optimal control problem governed by some ODE-PDE systems. That is, we obtain the necessary conditions for optimal control by showing the differentiability of the solution with respect to the control.

• Proceedings of the Korean Society of Applied Pharmacology
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• 1993.04a
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• pp.155-155
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• 1993

항우울약인 rolipran(RP)등 phosphodiesterase-억제 약(PDE-1)들이 thrombin(TB: 0.25 U/ml)에 의한 혈소판 응집에 미치는 작용을 가토-혈소판에서 일차 검토하였다. 신 PDE-1인 KR-30075(KR)의 $IC_{50}$/은 sodim nitroprusside의 것보다 낮았고 PDE-1들은 혈소판내 cAMP와 cGMP를 증가시켰으며 특히 KR은 타 PDE-1와 달리 I $P_3$를 감소시켰다. 아울러 rolipram은 cGMP와 I $P_3$를 증가시켰으나, amitriptyline(AT), sertraline(57), chlorpromazine(CP) 및 spermine은 I $P_3$를 증가시켰다. 그러나 이들과 PDE-1들은 강도의 차이는 있으나 모두 TB에 의한 혈소판응집을 모두 억제하였다. 따라서, PDE-1 중 IBMX(2$\times$$10^{-5}$M), KR(5$\times$10$_－7/M), 및 rolipram(10$_{-3}$M) 그 외에 항우울약인 AT(1.5 $\times$10$_－4/M) 와 ST(10$_－4/M) 및 항정신병약인 CP(10$_－4/M)둥이 혈소판내 I $P_3$, [C $a^{＋＋}$], Tx $B_2$, 및 PG $I_2$ 함량과 단백-인산화의 TB에 의한 변동에 미치는 영향을 검토하였다. 그 결과 TB에 의한 혈소판내 I $P_3$, [C $a^{＋＋}$], Tx $B_2$, 및 PG $I_2$ 함량의 증가가 PDE-1들과 항우울약들에 의하여 억제되었다 단, 항우울성약들과 CP는 정상 혈소판 I $P_3$를 증가시켰다. 아울러 혈소판-단백인산학에서 TB는 41-43 kD와 20 kD의 인산화를 현저히 증가시키며 19 kD의 인산화는 감소시켰고, PKC의 기질인 41-43 kD와 20 kD의 단백인산화가 PDE-1들과 항우울약들 뿐 아니라 CP에 의하여 현저히 억제되었다. 단, 20 kD 인산화에 대한 AT의 억제작용은 미약하였고, cAMP와 PDE-1들은 22kD 인산화를 증가시켰다. AT, ST, 및 CP는 A23187에 의한 41-43 kD 인산화는 현저히 억제하나 20 kD 인산화에는 영향을 미치지 않았고, PMA(3.2$\times$$10^{－7}$ M)에 의한 단백인산화에 대하여는 더 미약한 억제-효과를 나타내었다. 이상의 결과는 PDE-1과 항우울약들의 항혈소판작용은 PKC-기질인 41-43 kD와 20 kD의 인산화를 억제함에 기인되는 것으로 사료된다.다. 것으로 사료된다.다.

• Journal of the Korean Society of Propulsion Engineers
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• v.22 no.3
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• pp.81-89
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• 2018

In this study, the operating characteristics of a small-scale pulse detonation engine (PDE) were investigated experimentally for application as a small thruster and an igniter. The PDE was constructed using commercial gas tubes with an inner diameter of 4.22 mm. The operating and detonation propagation characteristics of the PDE were investigated over the ranges of equivalence ratios and operating frequencies. Measured detonation speed was close to 10% of the theoretical CJ values at 1 Hz and 5 Hz conditions. However, unstable propagation characteristics were shown at 20 Hz and lean conditions, where the velocity deficit was increased by 20~62%.

• Journal of the Korean Society of Propulsion Engineers
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• v.22 no.6
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• pp.11-18
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• 2018

A pulse detonation engine (PDE) requires high operating frequency greater than 100 Hz to get meaning thrust as a propulsion devise. Thus a PDE needs an ignition circuit operating precisely at high operating frequencies. In this paper AC(alternating current) and DC(direct current) types of ignition circuits were designed and compared. Each circuit was tested at operating frequencies from 16.66 to 100.00 Hz by measuring the input signal of each circuit and the voltage change in the primary coil of the transformer. Results show that the DC power circuit can attain a maximum error rate of 5.15% at higher operating frequencies, whereas the AC power circuit displays a negligible agreement with the operating signal at frequencies greater than 33.33 Hz. Therefore it is confirmed that DC-powered ignition circuit is preferable for the PDE operating at high frequencies.

• Archives of Pharmacal Research
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• v.23 no.1
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• pp.66-71
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• 2000

Peonjahwan, an oriental traditional medicine composed of crude herbal drugs and animal tissues is bitter and poorly water-soluble. To mask the bitterness of peonjahwan and enhance the release of bilirubin, one of the crude active ingredients of peonjahwan, peonja dry elixir (PDE), was prepared using a spray-dryer after extracting the crude materials in ethanol-water solution. coated peonja dry elixir (CPDE) was then prepared by coating the PDE with Eudragit acrylic resin. Panel assessed bitterness and release test of bilirubin from PDE and CPDE were carried out and compared with peonjahwan alone. PDE was found to have little effect upon the reduction of the bitterness of peonjahwan. However, the bitterness of CPDE was found to reduce to 1/4 of that of peonjahwan due to the encapsulation of crude active ingredients by the dextrin and Eudragit shell (P<0.05). The release rate of bilirubin from PDE and CPDE for 60 min increased about 3.5- and 2.5-fold, respectively, compared to peonjahwan at pH 1.2. It is concluded that CPDE, which masked the bitterness of peonjahwan and enhanced the release of bilirubin, is a preferable delivery system for peonjahwan.

• Korean Journal of Pharmacognosy
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• v.43 no.2
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• pp.184-191
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• 2012

The aim of this study was to explore the potent phosphodiesterase type 5 (PDE %) inhibitor from various herbal medicines for erectile dysfunctions. In this study, 61 herbal medicines, which were extracted with ethanol, have been investigated with PDE 5 assay using enzyme inhibitory activity on 22 species of herbal medicines. Of these, 5 species of herbal medicines, Cnidium monieri, Cuscuta chinensis, Epimedium koreanum, Morinda officinalis, and Tribulus terrestris were exhibited stronger inhibitory effect against phosphodiesterase 5 (PDE 5) among 61 species; Cnidium monieri ($IC_{50}=33.7{\mu}g/ml$), Cuscuta chinensis ($IC_{50}=65.7{\mu}g/ml$), Epimedium koreanum ($IC_{50}=90.3{\mu}g/ml$), Morinda officinalis ($IC_{50}=48.7{\mu}g/ml$) and Tribulus terrestris ($IC_{50}=32.5{\mu}g/ml$).

• Proceedings of the PSK Conference
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• 2002.10a
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• pp.250.1-250.1
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• 2002

DA-8159. a selective inhibitor of phosphodiesterase type 5 (PDE5: IC$\sub$50/ 5ng/$m\ell$). is being developed as a new treatment for erectile dysfunction. Since DA-8159 has been shown to inhibit PDE6 enzyme (IC$\sub$53ng/$m\ell$). we evaluated the effect of DA-8159 on electroretinogram (ERG) and retinal histopathology in rabbits. The effect of oral DA-8159 (5 to 30mg/kg) on ERG recordings was investigated at pre-treatment. 1 and 5 hrs after administration in rabbits. (omitted)