• Title/Summary/Keyword: Effect mechanism

Search Result 7,747, Processing Time 0.038 seconds

Inhibitory Effect of Anaphylaxis by WK101 and Mechanism of Action (WK101에 의한 아나필락시의 억제효과와 작용기전)

  • 이영미;김형룡
    • YAKHAK HOEJI
    • /
    • v.39 no.6
    • /
    • pp.616-621
    • /
    • 1995
  • The effect of WK101 on compound 48/80-induced anaphylaxis was studied in rat. WK101 was found to exhibit a inhibitory activity on the compound 48/80-induced anaphylaxis. WK101 also inhibited the serum histamine release induced in anaphylaxis by compound 48/80. The effect of WK101 on the histamine release from rat peritoneal mast cells was studied. WK101 ($10^{3}-1mg/ml$) inhibited the histamine release induced by compound 48/80($5{\;}\mu\textrm{g}/ml$) in rat peritoneal mast cells. To clarify the mechanism of these inhibitons, we investigated the effects of WK101 on cAMP and intracellular calcium content of rat peritoneal mast cell. The content of cAMP in mast cells, when WK101 was added, was increased transiently, and was significantly increased more 53 fold at 10 sec than that of basal cells. Moreover, WK101 inhibited intracellular calcium release induced by compoound 48/80. This results suggest that WK101 may be useful for the prevention and treatment of allergy-related disease.

  • PDF

Study of electric properties of pentacene field effect transistor using C- V and SHG measurements (C-V, SHG를 이용한 pentacene FFT의 전기적 특성 연구)

  • Lim, Eun-Ju;Takaaki, Manaka;Tamura, Ryosuke;Iwamoto, Mitsumasa
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
    • /
    • 2007.06a
    • /
    • pp.70-71
    • /
    • 2007
  • Analyzing pentacene field effect transistors (FETs) with Au source and drain electrodes as Maxwell-Wagner effect elements, electron and hole injection from the Au electrodes into the FET channel were examined using current-voltage (I-V), capacitance-voltage (C-V) and optical second harmonic generation (SHG) measurements. Based on these results, a mechanism of the hole and electron injection into pentacene from the Au electrodes and subsequently recombination mechanism with light-emitting in the pentacene layer are discussed, with taking into account the presence of trapped charges.

  • PDF

A Study on Dyeing Technology for Melange Effect in Wool Piece Dyeing (모직물을 포염에서 melange염색 효과를 나타내기 위한 기술개발과 응용에 관한 연구)

  • 이명환;정영진;최해욱;이언필
    • Textile Coloration and Finishing
    • /
    • v.10 no.3
    • /
    • pp.1-9
    • /
    • 1998
  • The dyeing properties of modified wool were examined with a series of acid, reactive and cationic dyes. Cationic agent and sulphamic acid were applied to wool fabric for dye assist and resist effect. Wool pretreated with cationic agent showed better uptake of acid and reactive dyes than did untreated wool. On the other hand, the dyeing behavior of wool pretreated with sulphamic acid was found as follows : Acid dyes were poorly resisted with a hydrophobic mechanism but acid dyes were strongly resisted with a hydrophilic mechanism. Reactive dyes were also found to be effectively resisted. Sulphamic acid introduces sulphonate group into wool's structure, it has increased better uptake of cationic dyes than untreated wool. The degree of differential uptake depends on the level of pretreatment and produces a variety of tone-on-tone and multicolor effect in piece dyeing.

  • PDF

Anti-inflammatory mechanism of bee vemon in Raw 264.7 cells and Synoviocyte

  • Hwang, In-Young;Park, Hye-Ji;Kim, Kee-Hyun;Lee, Seung-Ho;Oh, Goo-Taeg;Hong, Jin-Tae
    • Proceedings of the PSK Conference
    • /
    • 2003.10b
    • /
    • pp.98.1-98.1
    • /
    • 2003
  • Bee venom (BY) has been utilized to relieve pain and to treat inflammatory diseases such as rheumatoid arthritis (RA). However, the molecular mechanism by which BV-induced anti-arthritis effect has been not reported yet. Therefore, in the present study we investigated anti-inflammatory effect of BV in a murine marcrophage cell line Raw 264.7 cell and synoviocyte obtained from RA patients. The present data showed that BV has a preventive effect on lipopolysaccharide (LPS) and sodium nitroprusside (SNP) induced induction of COX-2, cPLA2 and iNOS. (omitted)

  • PDF

Trends in Treatment with and Mechanism of Moxibustion in Cancer Patients: A Review (암 환자에 대한 구법의 치료와 메커니즘에 대한 최신 국내외 연구 현황)

  • Yoon, Hae-chang;Kang, Ji-young;Kim, Jun-young;Joung, Jin-yong;Son, Chang-gue;Lee, Nam-heon;Cho, Jung-hyo
    • The Journal of Internal Korean Medicine
    • /
    • v.36 no.3
    • /
    • pp.361-379
    • /
    • 2015
  • Objectives This study aims to review and summarize existing evidence on moxibustion treatment for cancer patients. Methods Literature published until May 2015 in international journals were searched on PubMed, CAJ (CNKI-Medicine), NDSL (National discovery for science leaders), Sage Journal, ScienceDirect, Taylor&Francis Online (HSS), and Wiley Interscience (including Blackwell); and articles in Korean journals were searched on Korean Studies Information Service System (KISS), DBPIA, E-Article, KSI e-book, New article, Korea Institute of Science and Technology Information (KISTI), and Kyobo scholar. Results We analyzed 65 relevant studies. The number of studies conducted annually has increased and most are conducted in Korea and China. Moxibustion decreases the side effects of palliative treatment, thereby synergizing with anticancer treatment; it also improves the immune system, reduces tumor factors, and relieves symptoms. The mechanism of moxibustion is multi-fold: thermo, chemo, aero and kinetic. Only the kinetic effect is not significant. It also needs a complement to moxibustion because of harmful smoke. Conclusions Thus, the effect and mechanism of moxibustion in cancer patients was reviewed. There is an unmet need to develop a model of moxibustion and test it based on Korean medicine.

The Relaxant Activity of Safranal in Isolated Rat Aortas is Mediated Predominantly via an Endothelium-Independent Mechanism - Vasodilatory mechanism of safranal -

  • Razavi, Bibi Marjan;Amanloo, Mojtaba Alipoor;Imenshahidi, Mohsen;Hosseinzadeh, Hossein
    • Journal of Pharmacopuncture
    • /
    • v.19 no.4
    • /
    • pp.329-335
    • /
    • 2016
  • Objectives: Safranal is a pharmacologically active component of saffron and is responsible for the unique aroma of saffron. The hypotensive effect of safranal has been shown in previous studies. This study evaluates the mechanism for the vasodilatory effects induced by safranal on isolated rat aortas. Methods: To study the vasodilatory effects of safranal (0.2, 0.4 and 0.8 mM), we contracted isolated rat thoracic aorta rings by using $10^{-6}-M$ phenylephrine (PE) or 80-mM KCl. Dimethyl sulfoxide (DMSO) was used as a control. The vasodilatory effect of safranal was also evaluated both on intact and denuded endothelium aortic rings. Furthermore, to study the role of nitric oxide and prostacyclin in the relaxation induced by safranal, we incubated the aortic rings by using L-NAME ($10^{-6}M$) or indomethacin ($10^{-5}M$), each for 20 minutes. Results: Safranal induced relaxation in endothelium-intact aortic rings precontracted by using PE or KCl in a concentration-dependent manner, with a maximum relaxation of more than 100%. The relaxant activity of safranal was not eliminated by incubating the aortic rings with L-NAME ($EC_{50}=0.29$ vs. $EC_{50}=0.43$) or with indomethacin ($EC_{50}=0.29$ vs. $EC_{50}=0.35$), where $EC_{50}$ is the half maximal effective concentration. Also, the vasodilatory activity of safranal was not modified by endothelial removal. Conclusion: This study indicated that relaxant activity of safranal is mediated predominantly through an endothelium-independent mechanism.

Antioxidant Effect of Viola mandshurica W. Becker on the High Fat Diet-Induced Renal Oxidative Stress (고지방식이로 유도한 신장의 산화적 스트레스에 대한 자화지정(紫花地丁)의 항산화 효과)

  • Choi, Mi Hye;Park, In Sik
    • Journal of Physiology & Pathology in Korean Medicine
    • /
    • v.30 no.4
    • /
    • pp.250-256
    • /
    • 2016
  • The prevalence of renal disease is increased with the overweight and obesity. High fat diet-associated oxidative stress increases production of reactive oxygen species (ROS) and induces apoptosis. There are two types of antioxidant defense mechanisms for oxidative stress. One is the enzyme defense mechanism by antioxidant enzymes such as superoxide dismutase (SOD), and catalase (CAT). The other is non-enzyme defense mechanism by signaling molecules such as nuclear factor-like 2 (Nrf-2), HO-1. In this study, we induced obesity in mice with high fat diet for six weeks and thereafter administered orally Viola mandshurica for 4 weeks. V. mandshurica is known to clear heat, detoxify and cool blood, and subside a swelling effect. In the V. mandshurica administered group, the immunoreactive signal of the Tunel staining was weaker than that of obesity group. Proapoptotic Bax, caspase 3 immunoreactives of the V. mandshurica administered group was lower than those of obesity group, whereas anti-apoptotic Bcl-2 immunoreactity was higher in the V. mandshurica administered group. Antioxidant enzyme mechanism such as superoxide dismutase 2 (SOD2), catalase (CAT) immunoreactives of the V. mandshurica administered group and Antioxidant non-enzyme mechanism such as Nuclear factor-like 2 (Nrf2), Heme Oxygenase 1 (HO-1) immunoreactives of the V. mandshurica administered group was higher than those of obesity group. These results demonstrate that V. mandshurica had the antioxidant and anti-apoptosis effects on obese mice.

Kinetics and Mechanism of the Hydrolysis of Diazidophenylmethane Derivatives (Diazidophenylmethane 유도체들의 가수분해반응 메카니즘에 대한 반응속도론적 연구)

  • Kwon, Ki Sung;Seo, Jee Hyung;Lee, Yong Gu
    • Journal of the Korean Chemical Society
    • /
    • v.41 no.6
    • /
    • pp.313-319
    • /
    • 1997
  • Diazidophenylmethane derivatives(X: p-H, $p-OCH_3,\;p-F,\;p-CH_3$) were synthesized and the rate constants of hydrolysis of diazidophenylmethane derivatives were determined by UV spectrophotometry in 50:50(v/v) aqueous methanol at 25$^{\circ}C$. On the basis of rate equation, substituent effect, activation parameters, solvent effect, salt effect, and product analysis, it may be concluded that the hydrolysis of diazidophenylmethane derivatives proceed through $S_N2_CA$ mechanism below pH 2.0, while above pH 12.0 through $S_N2$ mechanism, and in the range of pH from 2 to 12 through $S_N1$ mechanism respectively.

  • PDF

Kinetic Study on Michael-type Reactions of 1-Phenyl-2-propyn-1-one with Alicyclic Secondary Amines: Effect of Medium on Reactivity and Mechanism

  • Hwang, So-Jeong;Park, Youn-Min;Um, Ik-Hwan
    • Bulletin of the Korean Chemical Society
    • /
    • v.29 no.10
    • /
    • pp.1911-1914
    • /
    • 2008
  • Second-order rate constants (kN) have been measured for Michael-type addition reactions of a series of alicyclic secondary amines to 1-phenyl-2-propyn-1-one (2) in MeCN at 25.0 ${\pm}$ 0.1 ${^{\circ}C}$. All the amines studied are less reactive in MeCN than in $H_2O$ although they are more basic in the aprotic solvent by 7-9 p$K_a$ units. The Bronsted-type plot is linear with $\beta_{nuc}$ = 0.40, which is slightly larger than that reported previously for the corresponding reactions in $H_2O$ ($\beta_{nuc}$ = 0.27). Product analysis has shown that only E-isomer is produced. Kinetic isotope effect is absent for the reactions of 2 with morpholine and deuterated morpholine (i.e., $k^H/k^D$ = 1.0). Thus, the reaction has been concluded to proceed through a stepwise mechanism, in which proton transfer occurs after the rate-determining step. The reaction has been suggested to proceed through a tighter transition state in MeCN than in H2O on the basis of the larger $\beta_{nuc}$ in the aprotic solvent. The nature of the transition state has been proposed to be responsible for the decreased reactivity in the aprotic solvent.

Aminolysis of 2,4-Dinitrophenyl and 3,4-Dinitrophenyl Benzoates: Effect of ortho-Nitro Group on Reactivity and Mechanism

  • Seo, Jin-A;Lee, Hye-Min;Um, Ik-Hwan
    • Bulletin of the Korean Chemical Society
    • /
    • v.29 no.10
    • /
    • pp.1915-1919
    • /
    • 2008
  • Second-order rate constants ($k_N$) have been measured spectrophotometrically for reactions of 3,4-dinitrophenyl benzoates (5b) with a series of alicyclic secondary amines in 80 mol % $H_2O$/20 mol % DMSO at 25.0 ${\pm}$ 0.1 ${^{\circ}C}$. The kinetic data have been compared with the data reported previously for the corresponding reactions of 2,4- dinitrophenyl benzoates (5a) to investigate the effect of changing the nucleofuge from 2,4-dinitrophenoxide to 3,4-dinitrophenoxide on reactivity and mechanism. The kinetic results show that aminolyses of 5a and 5b proceed through the same mechanism, i.e., a zwitterionic tetrahedral intermediate ($T^{\pm}$) with a change in the rate-determining step (RDS). Substrate 5a is more reactive than 5b when breakdown of $T^{\pm}$ is the RDS but less reactive when formation of $T^{\pm}$ is the RDS. Dissection of kN values into the microscopic rate constants (e.g., $k_1$ and $k_2/k_{-1 }$ ratio) has revealed that 5a results in larger $k_2/k_{-1}$ ratios but smaller k1 values than 5b for all the amines studied. Since 2,4-dinitrophenoxide is less basic and a better nucleofuge than 3,4-dinitrophenoxide, the larger $k_2/k_{-1}$ ratios determined for the reactions of 5a than for those of 5b are as expected. The steric hindrance exerted by the ortho-nitro group on 5a contributes to the smaller k1 values found for the reactions of 5a than for those of 5b.