Development of Sensitive Analytical Method of Rhodanthpyrone A by a LC-MS/MS and its Application to Bioavailability Study in Rats

Kang, Bitna,Yoon, Jeong A,Song, Im-Sook,Han, Young Taek,Choi, Min-Koo Korean Society for Mass Spectrometry 2019 Mass spectrometry letters Vol.10 No.3

A sensitive analytical method of rhodanthpyrone A in rat plasma was developed using a liquid chromatography-tandem mass spectrometry (LC-MS/MS). Rhodanthpyrone A and rhodanthpyrone B (internal standard) in rat plasma were extracted by a liquid-liquid extraction method with ethyl acetate. This extraction method gave results in high and reproducible extraction recovery in the range of 73.75-79.90% with no interfering peaks around the peak elution time of rhodanthpyrone A and B. The standard calibration curves for rhodanthpyrone A ranged from 0.5 to 2000 ng/mL were linear with $r^2$ > 0.994 and the inter- and intra-day accuracy and precision and the stability were within acceptance criteria. Using this validated analytical method, pharmacokinetics of rhodanthpyrone A following intravenous and oral administration of rhodanthpyrone A at doses of 2 mg/kg and 30 mg/kg, respectively, were investigated. Rhodanthpyrone A in rat plasma showed multi-exponential elimination pattern with high clearance and volume of distribution values. The absolute oral bioavailability of this compound was calculated as 3.7%. Collectively, the newly developed sensitive LC-MS/MS analytical method of rhodanthpyrone A could be successfully applied to investigate the pharmacokinetic properties of this compound and would be useful for the further studies on the efficacy, toxicity, and biopharmaceutics of rhodanthpyrone A.

디지털 방식의 인접면 접촉강도 측정장치의 개발 및 평가

최우진,김경화,김진아,강동완,오상호,Choi, Woo-Jin,Kim, Kyung-Hwa,Kim, Jin-A,Kang, Dong-Wan,Oh, Sang-Ho 대한치과보철학회 2007 대한치과보철학회지 Vol.45 No.5

Statement of problem: The proper contact relation between adjacent teeth in each arch plays an important role in the stability and maintenance of the integrity of the dental arches. Proximal contact has been defined as the area of a tooth that is in close association, connection, or touch with an adjacent tooth in the same arch. Purpose: The aim of this study was to develop a digital device for measuring the proximal tooth contact tightness by pulling a thin stainless steel strip (2mm wide, 0.03mm thick) inserted between proximal tooth contact. Material and method: This device consists of measuring part, sensor part, motor part and body part. The stainless steel strip was connected to a stain gauge. The strain gauge was designed to convert the frictional force into a compressive force. This compressive force was detected as a electrical signal and the electrical signal was digitalized by a A/D converter. The digital signals were displayed by a micro-processor. The pulling speed was 8mm/s. Results: For testing reliability of the device in vivo, two healthy young adults (A, B) participated in this experiment. The tightness of proximal tooth contact between the second premolar and the first molar of mandible (subject A) and maxilla (subject B) was measured fifteen times for three days at rest. We double-checked the accuracy of the device with a Universal Testing Machine. Output signals from the Universal Testing Machine and the measuring device were compared. Regression analysis showed high linearity between these two signals. In vivo test, no significant differences were found between measurements. Conclusion: This device has shown to he capable of producing reliable and reproducible results in measuring proximal tooth contact. Therefore, it was considered that this device was appropriate to apply clinically.

Reconstitution of ST2 (IL-1R4) specific for IL-33 activity; no suppression by IL-1Ra though a common chain IL-1R3 (IL-1RAcP) shared with IL-1

Jo, S.,Kim, E.,Kwak, A.,Lee, J.,Hong, J.,Lee, J.,Youn, S.,Bae, S.,Kim, B.,Ryoo, S.,Kang, T.B.,Her, E.,Choi, D.K.,Kim, Y.S.,Lee, Y.,Jhun, H.,Kim, S. Saunders Scientific Publications, W.B. Saunders ; 2016 Cytokine Vol.83 No.-

Interleukin-33 (IL-33) receptors are composed of ST2 (also known as IL-1R4), a ligand binding chain, and IL-1 receptor accessory protein (IL-1RAcP, also known as IL-1R3), a signal transducing chain. IL-1R3 is a common receptor for IL-1α, and IL-1β, IL-33, and three IL-36 isoforms. A549 human lung epithelial cells are highly sensitive to IL-1α and IL-1β but not respond to IL-33. The lack of responsiveness to IL-33 is due to ST2 expression. ST2 was stably transfected into A549 cells to reconstitute its activity. RT-PCR and FACS analysis confirmed ST2 expression on the cell surface of A549/ST2 cells. Upon IL-33 stimulation, A549/ST2 cells induced IL-8 and IL-6 production in a dose dependent manner while A549/mock cells remained unresponsive. There was no difference in IL-1α and IL-1β activity in A549/ST2 cells compared to A549/mock cells despite the fact that IL-33 shares IL-1R3 with IL-1α/β. IL-33 activated inflammatory signaling molecules in a time- and dose-dependent manner. Anti-ST2 antibody and soluble recombinant ST2-Fc abolished IL-33-induced IL-6 and IL-8 production in A549/ST2 cells but the IL-1 receptor antagonist failed to block IL-33-induced cytokines. This result demonstrates for the first time the reconstitution of ST2 in A549 human lung epithelial cell line and verified its function in IL-33-mediated cytokine production and signal transduction.

20대여성의 유방자가검진에 대한 지식과 자기효능감의 관계연구

강지혜,유리나,박민아,박신영,양은주,이주은,전시은,정윤혜,최연아,홍재하,이자형,정덕유,배노연 이화여자대학교 간호과학대학 2009 이화간호학회지 Vol.- No.43

The purpose of this study was to know relationship between important variables which influence lifestyle in college women`s health promotion, prove adjustable factors and provide basic data which develops nursing intervention health promotion program. The method of this study was descriptive correlational study. The convenience sample was 206 college woman who live alone in lodgings, dormitory, a reading room or off-campus housing. Research instruments were the Multidimensional Health Locus of Control(MHLC) developed by Wallston, Wallston & Devellis(1978), Interpersonal Support Evaluation List developed by Cohern, Hoberman(1983) and The Health Promotion Lifestyle Profile(HPLP) developed by Walker, Pender & Sechrist(1978) and the data was used after Factor Analysis. The result of this study was follows. 1. It can be found that the level of the college woman`s health promotion lifestyle was 2.46±.33 with higher fulfilling level: According to general characteristic, the level of health promotion lifestyle was 5% significant statistical differences by age and period of menstruation. 2. The level of health locus of control was 3.25±.31 with higher fulfilling level. 3. The interpersonal support level was 3.05±.44 with higher fulfilling level. 4. The level of interpersonal support turned out most convincing factor in health promotion lifestyle (9%). In addition to age factor, two factors was 10% power of explanation in whole health promotion.

Probing Out-of-Plane Charge Transport in Black Phosphorus with Graphene-Contacted Vertical Field-Effect Transistors

Kang, Junmo,Jariwala, Deep,Ryder, Christopher R.,Wells, Spencer A.,Choi, Yongsuk,Hwang, Euyheon,Cho, Jeong Ho,Marks, Tobin J.,Hersam, Mark C. American Chemical Society 2016 Nano letters Vol.16 No.4

<P>Black phosphorus (BP) has recently emerged as a promising narrow band gap layered semiconductor with optoelectronic properties that bridge the gap between semimetallic graphene and wide band gap transition metal dichalcogenides such as MoS2. To date, BP field-effect transistors have utilized a lateral geometry with in-plane transport dominating device characteristics. In contrast, we present here a vertical field-effect transistor geometry based on a graphene/BP van der Waals heterostructure. The resulting device characteristics include high on-state current densities (>1600 A/cm(2)) and current on/off ratios exceeding 800 at low temperature. Two distinct charge transport mechanisms are identified, which are dominant for different regimes of temperature and gate voltage. In particular, the Schottky barrier between graphene and BP determines charge transport at high temperatures and positive gate voltages, whereas tunneling dominates at low temperatures and negative gate voltages. These results elucidate out-of-plane electronic transport in BP and thus have implications for the design and operation of BP-based van der Waals heterostructures.</P>

여대생의 흡연실태와 흡연, 자아존중감, 우울 간의 관계연구 : 서울시내 4년제 대학교 중심으로

강선아,김세은,김지민,이미현,이수연,이예리,이현정,임나래,정민선,최보영,이자형,정덕유,김현경 이화여자대학교 간호과학대학 2009 이화간호학회지 Vol.- No.43

This study was conducted to find out the actual state of smoking among female college students, their knowledge of harmfulness of smoking and their attitude about abstinence from smoking and to analyze their reasons for starting smoking. By doing so, this study aimed to provide the preliminary data for the educational program that prevents smoking and helps smokers to quit cigarettes. Also, this study was conducted to compare the self-esteem and the propensity to depression between female smokers and female non-smokers. Before carrying out the study, the study subjects were investigated about their gender, age, living allowance, residential condition, religion, high school, and whether or not they repeated a year in their high school in order to identify the factors related to smoking. Also, in case of smokers, their smoking amount, their smoking frequency, their first experience of smoking, their attempt of quitting smoking, etc were examined to find out the state of smoking among female college students. Also, as the core aspect of this study, the relationship of self-esteem and depression with smoking was investigated. As a result, the examination of smoking's effects on depression and self-esteem showed that the stud y subjects in the smoker group had a higher level of depression, indicating that smoking is related to the degree of depression (p-value = .017) (smoker group average: 14.75, non-smoker group average: 11.28). In the aspect of self-esteem, it was shown that the more self-esteem the subjects have, the more frequently they smoke, suggesting that whether or not people smoke is not related to the degree of their self-esteem (p-value = .017).

The role of spinal interleukin-1β and astrocyte connexin 43 in the development of mirror-image pain in an inflammatory pain model

Choi, H.S.,Roh, D.H.,Yoon, S.Y.,Kwon, S.G.,Choi, S.R.,Kang, S.Y.,Moon, J.Y.,Han, H.J.,Kim, H.W.,Beitz, A.J.,Lee, J.H. Academic Press 2017 Experimental neurology Vol.287 No.1

<P>Although we have recently demonstrated that carrageenan-induced inflammation upregulates the expression of spinal interleukin (IL)-1 beta, which inhibits spinal astrocyte activation and results in the delayed development of Mirror-Image Pain (MIP), little is known regarding the mechanisms that underlie how spinal IL-1 beta inhibits the astrocyte activation. In this study, we examined the effect of spinal IL-1 beta on astrocyte gap junctions (GJ) and the development of MIP. Following unilateral carrageenan (CA) injection, mechanical allodynia (MA) was evaluated at various time points. Immunohistochemistry and Westem blot analysis were used to determine changes in the expression of GFAP and connexins (Cx) in the spinal cord dorsal horn. Carrageenan rats showed a delayed onset of contralateral MA, which mimicked the temporal expression pattern of spinal Cx43 (an astrocyte gap junctional protein) and GFAP. Intrathecal administration of an interleukin-1 receptor antagonist (IL-1ra) twice a-day on post-carrageenan injection days 0 to 3 caused a significant increase in contralateral MA and spinal Cx43 and GFAP expression. In addition, co-administration of IL-1 beta with IL-1ra blocked the IL-1ra-induced increase in contralateral MA and the upregulated expression of spinal Cx43 and GFAP. Finally, co-administration of carbenoxolone (CBX; a GJ decoupler) or Gap26 (a specific Cx43 mimetic blocking peptide) with IL-1ra significantly blocked the IL-1ra-induced early development of contralateral MA and the associated upregulation of spinal Cx43 and GFAP expression. These results demonstrate that spinal IL-1 beta suppresses Cx43 expression and astrocyte activation during the early phase of CA-induced inflammation resulting in the delayed onset of contra lateral MA. These findings imply that spinal IL-1 beta can inhibit astrocyte activation and regulate the time of induction of contralateral MA through modulation of spinal Cx43 expression. (C) 2016 Elsevier Inc. All rights reserved.</P>

Resveratrol induced reactive oxygen species and endoplasmic reticulum stress-mediated apoptosis, and cell cycle arrest in the A375SM malignant melanoma cell line

Heo, Jae-Rim,Kim, Soo-Min,Hwang, Kyung-A,Kang, Ji-Houn,Choi, Kyung-Chul D.A. Spandidos 2018 International journal of molecular medicine Vol.42 No.3

<P>Resveratrol, a dietary product present in grapes, vegetables and berries, regulates several signaling pathways that control cell division, cell growth, apoptosis and metastasis. Malignant melanoma proliferates more readily in comparison with any other types of skin cancer. In the present study, the anti-cancer effect of resveratrol on melanoma cell proliferation was evaluated. Treating A375SM cells with resveratrol resulted in a decrease in cell growth. The alteration in the levels of cell cycle-associated proteins was also examined by western blot analysis. Treatment with resveratrol was observed to increase the gene expression levels of p21 and p27, as well as decrease the gene expression of cyclin B. In addition, the generation of reactive oxygen species (ROS) and endoplasmic reticulum (ER) stress were confirmed at the cellular and protein levels using a 2′,7′-dichlorofluorescein diacetate assay, TUNEL assay and western blot analysis. Resveratrol induced the ROS-p38-p53 pathway by increasing the gene expression of phosphorylated p38 mitogen-activated protein kinase, while it induced the p53 and ER stress pathway by increasing the gene expression levels of phosphorylated eukaryotic initiation factor 2α and C/EBP homologous protein. The enhanced ROS-p38-p53 and ER stress pathways promoted apoptosis by downregulating B-cell lymphoma-2 (Bcl-2) expression and upregulating Bcl-2-associated X protein expression. In conclusion, resveratrol appears to be an inducer of ROS generation and ER stress, and may be responsible for growth inhibition and cell cycle arrest of A375SM melanoma cells.</P>

Prevalence of Anaplasma and Bartonella spp. in Ticks Collected from Korean Water Deer(Hydropotes inermis argyropus)

Jun-Gu Kang,Sungjin Ko,Heung-Chul Kim,Sung-Tae Chong,Terry A. Klein,Jeong-Byoung Chae,Yong-Sun Jo,Kyoung-Seong Choi,Do-Hyeon Yu,Bae-Keun Park,Jinho Park,Joon-Seok Chae 대한기생충학열대의학회 2016 Parasites, Hosts and Diseases Vol.54 No.1

Deer serve as reservoirs of tick-borne pathogens that impact on medical and veterinary health worldwide. In the Republic of Korea, the population of Korean water deer (KWD, Hydropotes inermis argyropus) has greatly increased from 1982 to 2011, in part, as a result of reforestation programs established following the Korean War when much of the land was barren of trees. Eighty seven Haemaphysalis flava, 228 Haemaphysalis longicornis, 8 Ixodes nipponensis, and 40 Ixodes persulcatus (21 larvae, 114 nymphs, and 228 adults) were collected from 27 out of 70 KWD. A total of 89/363 ticks (266 pools, 24.5% minimum infection rate) and 5 (1.4%) fed ticks were positive for Anaplasma phagocytophilum using nested PCR targeting the 16S rRNA and groEL genes, respectively. The 16S rRNA gene fragment sequences of 88/89 (98.9%) of positive samples for A. phagocytophilum corresponded to previously described gene sequences from KWD spleen tissues. The 16S rRNA gene fragment sequences of 20/363 (5.5%) of the ticks were positive for A. bovis and were identical to previously reported sequences. Using the ITS specific nested PCR, 11/363 (3.0%) of the ticks were positive for Bartonella spp. This is the first report of Anaplasma and Bartonella spp. detected in ticks collected from KWD, suggesting that ticks are vectors of Anaplasma and Bartonella spp. between reservoir hosts in natural surroundings.

X-ray Absorption and Photoemission Spectroscopy Study of Nd½A½Mn₁-yCryO₃ (A=Ca, Sr)

J.-S. Kang,J. H. Kim,S. W. Han,K. H. Kim,E. J. Choi,A. Sekiyama,S. Kasai,S. Suga,T. Kimura 한국자기학회 2003 Journal of Magnetics Vol.8 No.4

Valence states and electronic structures of Cr-doped Nd½A½MnO₃ (NAMO; A=Ca, Sr) manganites have been investigated using x-ray absorption spectroscopy (XAS) and high-resolution photoemission spectroscopy (PES). All the Cr-doped NAMO systems exhibit the clear metallic Fermi edges in the Mn e_g PES spectra near E_F. The spectral intensity at E_F is higher for Cr-doped Nd½Sr½MnO₃ (NSMO) than for Cr-doped Nd½Ca½MnO₃ (NCMO), reflecting the stronger metallic nature for NSMO than for NCMO. The measured Cr 2p XAS spectra are found to be very similar to that of Cr₂O₃, indicating that Cr ions in Cr-doped NAMO are in the trivalent Cr³+ states (t³_(2g)). The Cr 2p XAS data are consistent with the Cr 3d PES spectra located at ~1.3 eV below EF and having no emission near E_F.