• Title/Summary/Keyword:  inhibition

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The Effect of Repetitive Transcranial Magnetic Stimulation on H-Reflex Inhibition and Fascilitation of Range of Motion of Spastic Ankle Joint in Chronic Stroke Patients (만성 뇌졸중 시 반복경두개자기자극에 의한 경직성 발목관절의 관절가동 범위 향상 및 H-반사 억제 효과)

  • Cho, Mi-Suk
    • Journal of the Korean Society of Physical Medicine
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    • v.6 no.1
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    • pp.71-79
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    • 2011
  • Purpose : The purpose of this study was carried out to investigate the effect of repetitive transcranial magnetic stimulation on increase of H-reflex inhibition and fascilitation of range of motion of spastic ankle joint in chronic stroke patients. Methods : 30 chronic stroke patients were randomly divided into three groups, a control group(placebo rTMS group), 5 Hz rTMS group and manual therapy group. The MAS and ROM of ankle joint and H-reflex inhibition of soleus muscle were evaluated on each group. Results : The rTMS group decreased MAS of ankle joint and increased H-reflex inhibition of soleus muscle, and ROM of ankle joint than manual therapy group. The placebo rTMS group did not affected the change of MAS, ROM of ankle joint and H-reflex inhibition of soleus muscle. Conclusion : The rTMS was a good therapeutic tool to improve the foot drop in the chronic stroke patients.

Removal and Regrowth Inhibition of Microcystis aeruginosa using Artemisia asiatica Extracts (쑥 추출액을 이용한 Microcystis aeruginosa 제거 및 성장억제 연구)

  • Choi, Hee-Jeong
    • Journal of Korean Society on Water Environment
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    • v.33 no.4
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    • pp.441-448
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    • 2017
  • Microcystis aeruginosa (M. aeruginosa) is a cyanobacterium species that can form harmful algal blooms in freshwater bodies worldwide. The use of Artemisia asiatica extracts to control M. aeruginosa inhibition will be environmentally friendly and promising. Artemisia asiatica extracts removed successfully upto 88% of M. aeruginosa pH 8 at $25^{\circ}C$ of temperature. These results was indicated that the amount of 2.24 g/L Artemisia asiatica extracts was removed 1g dryweight/L of M. aeruginosa. The kinetic data showed substrate inhibition kinetics and maximum growth rate was obtained when the M. aeruginosa was grown in medium containing 2.5 g/L of initial concentration of Artemisia asiatica extracts. In the various growth control models, Luong model showed the highest correlation coefficient of 0.9916. Therefore, the Luong model was the most suitable control model for the growth control of M. aruginosa using Artemisia asiatica extracts. In conclusion, the growth control of M. aruginosa using Artemisia asiatica extracts can be applied in the field without controlling the temperature and pH of rivers and streams, and it is possible to control the growth of M. aruginosa efficiently in a short time. The natural extract, Artemisia asiatica extracts, can be a promising inhibition due to its high efficiency and low dose requirements.

Effect of Hydroquinone on Ruminal Urease in the Sheep and its Inhibition Kinetics in vitro

  • Zhang, Y.G.;Shan, A.S.;Bao, J.
    • Asian-Australasian Journal of Animal Sciences
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    • v.14 no.9
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    • pp.1216-1220
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    • 2001
  • Effect of hydroquinone (HQ) on rumen urease activity was studied. Hydroquinone at concentrations of 0.01 ppm, 0.1 ppm, 1 ppm, and 10 ppm inhibited urease activity of intact rumen microbes in vitro by 25%, 34%, 55% and 64% respectively. In the presence of low concentrations of $\beta$-mercaptoethanol, rumen urease could be solubilized and partially purified. The Km for the enzyme was $2{\times}10^{-3}$ M with Vmax of $319.4{\mu}moles/mg$ min. The kinetics of inhibition with partially purified rumen urease was investigated. The result showed that the inhibitory effect was not eliminated by increasing urea concentrations indicating a noncompetitive effect in nature with an inhibition constant $1.2{\times}10^{-5}$ M. Hydroquinone at the concentration of 10 ppm produced 64% urease inhibition, did not affect ruminal total dehydrogenase and proteolytic enzyme (p>0.05), but increased cellulase activity by 28% (p<0.05) in vitro. These results indicated that hydroquinone was a effective inhibitor of rumen urease and could effectively delay urea hydrolysis without a negative effect. The inhibitor appeared to offer a potential to improve nitrogen utilization by ruminants fed diets containing urea.

Effect of Samhwasan on Na-K-ATPase Activity in Microsomal Fraction of Rabbit Heart Ventricles (삼화산(三和散)이 심장(心臟) Na-K-ATPase 활성(活性)에 미치는 영향(影響))

  • Shin, Hyeon-Chul;Yoon, Cheol-Ho;Jeong, Ji-Cheon
    • The Journal of Korean Medicine
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    • v.17 no.2 s.32
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    • pp.264-276
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    • 1996
  • This study was carried out to evaluate the effect of Samhwasan on the Na-K-ATPase activity of heart muscle. The Na-K-ATPase activity was prepared from rabbit heart ventricles. Samhwasan markedly inhibited the Na- K - ATPase activity in a dose-dependent manner with an estimated $I_{50}$ of 0.56%. Hill coefficient was 1.70, indicating that the enzyme has more than one binding site for the Samhwasan. Inhibition of enzyme activity by Samhwasan increased as pretreatment time was prolonged. Inhibition by the drug was not affected by a change in enzyme protein concentration. Kinetic studies of substrate activation of the enzyme indicated classical noncompetitive inhibition, showing significant reduction in Vmax without a change in Km value. Inhibitory effect by Samhwasan was not altered by changes in concentration of $Mg^{2+}$, $Na^+$ or $K^+$, dithiothreitol. a sulfhydryl reducing reagent, did not protect the inhibition of Na-K-ATPase activity by Samhwasan combination of Samhwasan and ouabain showed a cumulative inhibition fashion. These results suggest that Samhwasan inhibits Na-K-ATPase activity of heart ventricles with an unique binding site different from that of ATP, $Mg^{2+}$, $Na^+$ or $K^+$ and ouabain.

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Prolyl Endopeptidase Inhibitory Activity of 6-O-Palmitoyl L-Ascorbic Acid

  • Park, Yoon-Seok;Paik, Young-Sook
    • Journal of Applied Biological Chemistry
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    • v.49 no.3
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    • pp.110-113
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    • 2006
  • Prolyl endopeptidase (PEP, EC 3.4.21.26, also referred to as prolyl oligopeptidase) degrades proline containing, biologically active neuropeptides such as vasopressin, substance P and thyrotropin-releasing hormone by cleaving peptide bonds on carboxyl side of prolyl residue within neuropeptides of less than 30 amino acids. Evaluation of PEP levels in postmortem brains of Alzheimer's disease patients revealed significant increases in PEP activity. Therefore, a specific PEP inhibitor can be a good candidate of drug against memory loss. Upon our examination for PEP inhibitory activity from micronutrients, ascorbic acid (vitamin C) showed small but significant PEP inhibition (13% PEP inhibition at $8{\mu}g{\cdot}ml^{-1}$). Palmitic acid showed almost no PEP inhibition. However, 6-O-palmitoyl ascorbic acid ($\underline{1}$) showed 70% PEP inhibition at $8{\mu}g{\cdot}ml^{-1}$ indicating that hydrophobic portion of the compound $\underline{1}$ may facilitate the inhibitory effect. $IC_{50}$ value of compound $\underline{1}$ was $12.6{\pm}0.2{\mu}M$. The primary and secondary Lineweaver Burk and Dixon plots for compound $\underline{1}$ indicated that it is a non-competitive inhibitor with inhibition constant (Ki) value of $23.7{\mu}M$.

Dose Motor Inhibition Response Training Using Stop-signal Paradigm Influence Execution and Stop Performance?

  • Son, Sung Min
    • The Journal of Korean Physical Therapy
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    • v.32 no.2
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    • pp.70-74
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    • 2020
  • Purpose: This study examined whether 1) the motor inhibition response as cognitive-behavioral component is learning though a stop signal task using stop-signal paradigm, and 2) whether there is a difference in the learning degree according to imagery training and actual practice training. Methods: Twenty young adults (males: 9, females: 11) volunteered to participate in this study, and were divided randomly into motor imagery training (IT, n=10) and practice training (PT, n=10) groups. The PT group performed an actual practice stop-signal task, while the IT group performed imagery training, which showed a stop-signal task on a monitor of a personal computer. The non-signal reaction time and stop-signal reaction time of both groups were assessed during the stop-signal task. Results: In the non-signal reaction time, there were no significant intra-group and inter-group differences between pre- and post-intervention in both groups (p>0.05). The stop-signal reaction time showed a significant difference in the PT group in the intra-group analysis (p<0.05). On the other hand, there was no significant intra-group difference in the IT group and inter-group difference between pre- and post-intervention (p>0.05). Conclusion: These results showed that the motor inhibition response could be learned through a stop-signal task. Moreover, these findings suggest that actual practice is a more effective method for learning the motor inhibition response.

CALMOSTINOL, A NEW CALPAIN INHIBITOR PRODUCED BY AN ACTINOMYCETE

  • Chung, Myung-Chul;Lee, Ho-Jae;Lee, Choong-Hwan;Chun, Hyo-Kon;Kho, Yung-Hee
    • Proceedings of the Korean Society of Applied Pharmacology
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    • 1998.11a
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    • pp.127-127
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    • 1998
  • Specific inhibitors of a calcium activated neutral protease calpain could be used for the treatment of neurodegenerative diseases, cataract and muscular dystrophy diseases because of their therapeutic effects. In the course of screening for potential calpain inhibitors from microorganisms, a new analogue of chymostatins named calmostinol was isolated from the culture filtrate of an actinomycete. The MW was determined to be 596 [(M + H)$\^$+/] by FAB-MS in glycerol matrix. The structure was elucidated to be N-[((S)-1-carboxy-2-phenylethyl)-carbamoyl]-${\alpha}$-[2- iminohexahydro-4(S)-pyrimidyl]-L-glycyl- L-valyl-phenylalaninol, by the spectroscopic methods such as NMR and MS fragmentation studies. Calmostinol exhibited strong activity against calpain while not against a Ca$\^$2+/ -independent cysteine protease papain.

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Effects of muscarinic receptor stimulation on the thyrotropin-induced thyroxine release in the guinea pig thyroid (기니픽 갑상선에서 Thyrotropin에 의한 thyroxine 유리에 대한 muscarinic 수용체 자극효과)

  • Kim, Hong-hyun;Kim, Jin-shang
    • Korean Journal of Veterinary Research
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    • v.39 no.1
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    • pp.55-61
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    • 1999
  • The present experiments were performed to examine the effects of acetylcholine (ACh) and carbachol (CC) on thyroxine ($T_4$) release and any possible relation between inhibition of $T_4$ release and signaling pathway in guinea pig thyroids. The thyroids were incubated in the medium containing the test agents, samples of the medium were assayed for $T_4$ by EIA kits. ACh and CC inhibited the TSH-stimulated $T_4$ release. These inhibition were reversed by atropine, but not by d-tubocurarine. The inhibitory effects of ACh on $T_4$ release were prevented by $M_{1^-}$ and $M_{3^-}$muscarinic antagonists and its inhibition was also slightly reversed by $M_{2^-}$ and $M_{4^-}$muscarinic antagonists. R59022, like ACh and CC, also inhibited the TSH-stimulated $T_4$ release. This inhibition was reversed by protein kinase C inhibitor and $Ca^{2+}$ channel blocker. The present study suggests that cholinergic inhibition of $T_4$ release from thyroids can be induced mainly by activation of the $M_{1^-}$ or $M_{3^-}$ receptors and that it is mediated through the muscarinic receptorstimulated protein kinase C activation.

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The Effect of Fungicides on Mycelial Growth and Conidial Germination of the Ginseng Root Rot Fungus, Cylindrocarpon destructans

  • Shin, Jong-Hwan;Fu, Teng;Park, Kyeong Hun;Kim, Kyoung Su
    • Mycobiology
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    • v.45 no.3
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    • pp.220-225
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    • 2017
  • Ginseng root rot caused by Cylindrocarpon destructans is the most destructive disease of ginseng. Six different fungicides (thiophanate-methyl, benomyl, prochloraz, mancozeb, azoxystrobin, and iprodione) were selected to evaluate the inhibitory effect on the mycelial growth and conidial germination of C. destructans isolates. Benomyl and prochloraz were found to be the most effective fungicides in inhibiting mycelial growth of all tested isolates, showing 64.7% to 100% inhibition at a concentration of $10{\mu}g/mL$, whereas thiophanate-methyl was the least effective fungicide, showing less than 50% inhibition even at a higher concentration of $100{\mu}g/mL$. The tested fungicides exhibited less than 20% inhibition of conidium germination at concentrations of 0.01, 0.1, and $1{\mu}g/mL$. However, the inhibition effect of mancozeb on condium germination of C. destructans was significantly increased to 92% to 99% at a higher concentration of $100{\mu}g/mL$, while the others still showed no higher than 30% inhibition.

Inhibition Effect of Against Angiotensin Converting Enzyme of Flavan-3-ols isolated Korean Green Tea (한국산 녹차로부터 분리한 Flavan-3-ol 화합물의 Angiotensin Converting Enzyme 저해 효과)

  • Cho, Young-Je;An, Bong-Jeun;Choi, Cheong
    • Korean Journal of Food Science and Technology
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    • v.25 no.3
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    • pp.238-242
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    • 1993
  • For the Purpose of utilizing tannins in the functional foods and crude drugs, the enzyme inhibition of tannins isolated from Korean green tea were determined. Acetone extract from Korean green tea showed inhibition effect against the angiotensin converting enzyme. The galloyl tannins showed higher inhibition activity against angioteosin converting enzyme than the nongalloyl tannins. In terms of stereo isomers, (-)-epicatechins had higher inhibition activity than the (+ )-catechins. The synergistic activity was also observed. Tannins isolated from Korean green tea appeared to be incompetitive inhibitor against the angiotensin converting enzyme.

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