• Title/Summary/Keyword: inhibition test

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Use of Duckweed (Lemna gibba) Growth-Inhibition Test to Evaluate the Toxicity of Chromate in Korea (환경독성 평가를 위한 좀개구리밥(Lemna gibba)의 성장저해시험법에 관한 연구)

  • 김은주;이성규
    • Environmental Analysis Health and Toxicology
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    • v.16 no.4
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    • pp.205-209
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    • 2001
  • Lemna gibba was newly cultured and provided for toxicity tests. In this study, the chromate toxicity tests for Lemna gibba were performed according to the OECD Lemna growth inhibition test guideline. The test species was Lemna gibba, and the tests were repeated 5 times. To evaluate the toxicity test results, the average specific growth rate, EC50, 95% confidential limit, and variances were calculated. The test performance was analyzed by the doubling time and test statistics. The average values of EC50 data determined by logistic and linear interpolation curves were 25.9 ppm and 35.4 ppm respectively (by chromate concentration). The doubling time of all controls were below 2.5 day, so all tests passed the criteria for the test performance. This study introduced a new test method, Lemna growth inhibition test, which is provided for the hazard assessment of aquatic environment.

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In Vitro AChE Inhibition Tests of Insecticides Using Electric eel and Housefly AChE (전기뱀장어 및 집파리 AChE를 이용한 살충제의 In Vitro AChE 저해 시험)

  • 이시혁;이준호;조광연
    • Korean journal of applied entomology
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    • v.31 no.2
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    • pp.122-132
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    • 1992
  • Experiments were conducted to establish an in vitro AChE inhibition test system to evaluate the potency of AChE inhibition of new chemical compounds. For a fixed time inhibition test, optimal inhibition (incubation) time to evaluate their AChE inhibition potency was 10 min. for AChE inhibitors such as DFP, DDVP, and paraoxon. The concentration of new chemical compounds with an ester group for evaluation of their inhibition potency was 10 $\mu$M under 10 min. preincubation conditions. However, the stepwise inhibition test with higher concentrations seemed to be needed for other chemical compounds. For a progressive inhibition test to calculate inhibition constants such as $K_d$, $K_3$ and $K_i$, extremely low $K_d(1.3\times10-^85.6\times10^{-7})$ and $K_3$(0. 21-0.27 $min^{-1}$) were observed under lagged preincubation time (0.8-13.3 min) and low in¬hibitor concentrations $(1\times10-^92\times10-^6M)$. However, this method seemed to be useful for comparison of AChE inhibition potency among inhibitors. Differences in inhibition potency among DFP, paraoxon, and KH501 were due to the differences in $K_d$, in other words, differences in affinities between inhibitors and AChEs. Therefore, AntiChE screening should consist of two steps. The first step is to evaluate the potency of AChE inhibition based on $I_50$ valuse obtained from fixed time inhibition tests. The second step is to study inhibition patterns and characteristics of chemical compounds selected in the first step.

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Experimental Studies on Differentiation of Typical and Atypical Mycobacterium by Migration Inhibition Test (Migration Inhibition Test에 의한 병원성 및 비정형항산균과의 감별에 관한 연구)

  • Kim Jong Myeon
    • Journal of the korean veterinary medical association
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    • v.13 no.5
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    • pp.311-316
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    • 1977
  • The studies on differentiation of pathological and atypical acid fast bacteria were reported by many authers. The tuberculin skin test that is widely utilized to diagnose tuberculosis of the dairy cattle was of smaller significance for the certification o

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Screening for Antioxidative and Antimutagenic Capacities in 7 Common Vegetables Taken by Korean

  • Oh, Se-In;Lee, Mee-Sook
    • Proceedings of the Korean Journal of Food and Nutrition Conference
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    • 2003.07a
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    • pp.77-77
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    • 2003
  • This study was performed to investigate the antioxidative effect as the inhibition of MDA and BSA conjugation reaction, inhibition of lipid peroxidation and the scavenging effect on DPPH radical, and antimutagenic capacities as the Ames test in 7 common vegetables taken by Korean for suggestion of prevention and dietetic treatment of chronic diseases and development of antioxidative and antimutagenic functional food. The water extracted fractions of perilla leaves were most effective in the inhibition of MDA and BSA conjugation reaction showing 77.2% of inhibition rate among 7 vegetables. The inhibition rates of ethanol extracted fractions of sedum and wild water dropwort on the lipid peroxidation were 67.1% and 61.5%, respectively. The ethanol extracted fractions of crown daisy and wild water dropwort showed the most effective results among 7 vegetables in the DPPH radical scavenging capacities showing inhibition rate of 78.8% and 73.6%, respectively. The indirect and direct antimutagenic effects of ethanol extract of 7 vegetables were examined by Ames test using Salmonella typimurium TA98 and TA100. Inhibitory effects of wild water dropwort was superior to the other vegetables on the Ames test. These results suggest that common 7 vegetables taken by Korean are believed to be a possible antioxidative and antimutagenic capacities, although the resultswere different, some or less, according to the assay method and vegetables used.

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The Change of ${\alpha}$-motor neuron excitability in Spastic Stroke Patients by Pre-tibia Muscle Isometric Contraction (전경골근 등척성 수축에 의한 경직성 뇌졸중 환자의 비복근 ${\alpha}$-운동 신경원 흥분 변화)

  • Kim, Jong-Soon;Lee, Hyun-Ok;Ahn, So-Youn
    • The Journal of Korean Academy of Orthopedic Manual Physical Therapy
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    • v.11 no.1
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    • pp.11-28
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    • 2005
  • Spasticity has been defined as "a motor disorder characterized by a velocity-dependent increased in tonic stretch reflexes with exaggerated tendon jerks, resulting from hyperexcitability of the stretch reflex, as one components of the upper motorneuron syndrome". Spasticity is one of the common symptoms of stroke patients and frequently interferes with the motor functions such as gait, posture and activities of daily living. Therefore, its management is becoming a major issue in physical therapy. The purpose of this study was to determined the effects of reciprocal inhibition by isometric contraction of pre-tibia muscle on spasticity in hemiplegic patients through Hoffmann reflex. The subjects were consisted 45 patients who had hemiplegia due to stroke. All subjects randomly assigned to 3 group: manual reciprocal inhibition program group(manual group), neuromuscular electrical stimulation group(NMES group) and control group. The manual group received voluntary isometric contraction of pre-tibia muscle. The NMES group received neuromuscular electrical stimulation on tibialis anterior. The control group was not received any therapeutic intervention. Before and after experiments, Hoffmann reflex, M-wave and Modified Ashworth scale was measure in all patients. The data of 30 patients who complete experimental course were statistically analysed. Modified Ashworth scale were significantly decreased after experiment in manual group(p<.01). The Hmax/Mmax ratios were significantly decreased after experiment in manual group(p<.o1). There were no statistical difference between pre-test and post-test with modified Ashworth scale in NMES group(p>.01). There were no statistical difference between pre-test and post-test with Hmax/Mmax ratios in NMES group(p>.01). There were no statistical difference between pre-test and post-test with modified Ashworth scale in control group(p>.01). There were no statistical difference between pre-test and post-test with Hmax/Mmax ratios in control group(p>.01). The present results revealed that reciprocal inhibition which produced by voluntary isometric contraction of pre-tibia muscle can be reduce spasticity of gastrocnemius. Therefore, reciprocal inhibition is useful to improve functional activities in hemiplegic patient. Further study should be done to analyse the effects of intervention duration of reciprocal inhibition, appropriate muscle contraction, optimal time to apply the reciprocal inhibition in more long period.

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Studies on Toxoplasmosis. - II. Serological Survey of Toxoplasmosis on Swine by Complement Fixation Inhibition Test. (Toxoplasmosis에 관한 연구 - 제2보:보체결합저지반응에 의한 돈 Toxoplasmosis의 분포조사.)

  • Mun Jae Bong
    • Journal of the korean veterinary medical association
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    • v.9 no.2
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    • pp.23-34
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    • 1965
  • In 1957, a Toxoplasma infection among swine was first discovered in Korea. Thereafter, Complement Fixation Inhibition Test was applied to 2,017 swine serum samples which were obtained from all over the country except Cheju Island. Significant results are

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Infant Emotionality, Parenting, and 3-Year Inhibition (영아기 정서성 및 부모의 양육행동에 따른 3세 아동의 행동억제)

  • 박성연
    • Journal of the Korean Home Economics Association
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    • v.36 no.4
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    • pp.19-34
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    • 1998
  • The purpose of this study was to examine early emotionality and mothering and fathering antecedents of inhibition of children at age 3 years in a sample of 100 children(51 boys; 49 girls). In order to assess child's behavioral inhibition and mothering, the behaviors of each child-mother dyad was videotaped in a structured lab situation. Data on Fathering behavior were gathered through questionnaires. 2X2ANOVA, Hierachical Regression Analyses and Fisher's Z test were conducted for the statistical analyses. The main results were as follows; 1) Only small portion of the variance in subsequent inhibition could be explained by early emotionality(i.e.negative, positive, and the interaction of both emotionality). 2) High negativity coupled with low positivity in infancy predicted high inhibition especially for girls. 3) In general, sensitive mothering and appropriateness of mothers' response were related to child's low inhibition, while parental intrusiveness and negative affect increased child's inhibition. 4) Mothering appeared more influential in the case of children who showed low positivity during infancy. The importance of distinguishing positive and negative emotionality in infancy and studying parental behavior to predict child's inhibition were discussed.

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Phytoplankton as Standard Test Species for Marine Ecotoxicological Evaluation (해양생태독성평가를 위한 표준시험생물로서의 식물플랑크톤에 관한 연구)

  • Park Gyung-Soo;Lee Sang-Hee;Lee Seung-Min
    • Journal of Environmental Science International
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    • v.14 no.12
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    • pp.1129-1139
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    • 2005
  • A series of experiments was conducted to identify the potential of five phytoplankton species as standard test species for marine ecotoxicological tests. The candidate phytoplankton species are Skeletonema costatum, Heterosigma akashiwo, Prorocentrum micans, Isochrysis galbana, and Tetraselmis suecica. Salinity tolerance and sensitivity on potassium dichromate as a reference material were identified. Toxicity of eleven ocean dumped sewage sludges and four red tide expellent extracts were estimated by the inhibition of population growth rates (PGR) of marine diatom S. costatum, While most species revealed relatively weak tolerance on salinity, T. suecica demonstrated the highest salinity tolerance ranged from $5\~35$ psu and the others $15\~35$ psu. H. akashiwo revealed the highest sensitivity as 72h $IC_{50}$=0.76mg/L and T. suecica the lowest as 72h $IC_{50}$=8.89mg/L on potassium dichromate. Sludge extracts from industrial waste, domestic sewage and livestock farm waste sludge showed high toxicity as 72h $IC_{50}$<$2\%$ and lowest toxicity from filtration bed sludge as 72h $IC_{50}$=$30.50\%$ NOEC (No Observed Effective Concentration) of sludge extract ranged from <$0.4\%$ to $1.6\%$ and this indicated high phytotoxicity of ocean dumped sewage sludge. The test sensitivity of phytoplankton PGR inhibition was much higher than those of marine rotifer Brachionus plicatilis mortality test and bioluminescent inhibition test by marine bacteria Vibrio fischeri, and comparable with the sea urchin (Strongylocentrotus intermedius) fertilization test. As a result the phytotoxicity test using phytoplankton PGR inhibition ($IC_{50}$) must be a useful tool for marine phyto-toxicological evaluation of ocean dumped materials.

Anti-depressant Effect of the Extracts of Aconitum carmichaeli (부자(附子)의 우울증 억제효과에 관한 연구)

  • Chang, Moon-Kyoo;Kim, Geun-Woo;Koo, Byung-Soo
    • Journal of Oriental Neuropsychiatry
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    • v.20 no.3
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    • pp.49-64
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    • 2009
  • Objectives : The water and methanol extracts of Aconitum carmichaeli(Aconiti Tuber Preparat) were investigated for their anti-depressant effects. Methods : In this study, reserpine-induced hypothermia test, tail suspension test and hot plate test. Additionally, the brain monoamine oxidase activity was determined in vivo. Results: In the reserpine-induced hypothermia test, both extracts suppressed the fall of body temperature compared to the control group in a dose-dependent manner, suggesting the inhibition on hypothermia. In the tail suspension test, the methanol extract dose-dependently reduced the duration of immobility by 28.4% at a dose of 1 g/kg compared to control group, which is more effective than the water extract. In the hot plate test, the water extract and methanol extract increased the jump latency time compared to the control group, showing the inhibition rate of 198% and 182%, respectively, at a dose of 1 g/kg. Methanol extracts potently inhibited the brain monoamine oxidase activity in an in vivo assay compared to the control group, showing 84.6% inhibition, but the water extract revealed very weak activity. Conclusions : Above results suggested that the extract of Aconitum carmichaeli can be useful for the prevention and treatment of depression.

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Experimental study of Gagam-Cheongsang BangPungTang on the anti-inflammatory effects (가감청상방풍탕(加減淸上防風湯)의 항염증 효과에 대한 실험적 연구)

  • Seo, Eun-Sung;Hwang, Chung-Yeon;Kim, Nam-Kwen
    • The Journal of Korean Medicine Ophthalmology and Otolaryngology and Dermatology
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    • v.21 no.2
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    • pp.54-70
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    • 2008
  • Background and Object : This study was carried out to investigate the effects of GCSBPT (Gagam-Cheongsang BangPungTang) on the in vitro and in vivo anti-inflammatory reactions. Methods : Vascular permeability and Cyclooxygenase inhibition assay are examined in vitro and nitric oxide inhibition assay, radical scavenging activity test, $TNF-{\alpha}$, COX-2 inhibition test are examined in vivo. Results : GCSBPT showed inhibitory effects on vascular permeability and leukocyte migration in animal test. In cyclooxygenase 2 inhibition assay, an ethanol extract of GCSBPT inhibited prostaglandin E2 generation at a concentration of $10{\mu}g/ml$. Among the herbal ingredients of GCSBPT, ethanol extracts of Nepetae Spica exhibited potent inhibitory activities. Ethanol extract of GCSBPT inhibited the release of nitric oxide and the gene expression of inducible nitric oxide synthase in RAW 246.7 cells stimulated by lipopolysaccharide. Ethanol extract of GCSBPT exhibited radical scavenging activity of 54% at $100{\mu}g/ml$. Among the herbal ingredients of GCSBPT. Conclusions : According to the above results, I expected that GCSBPT was a potent anti-inflammatory prescription.

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