• Title/Summary/Keyword: $D_{50}$

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Interaction of Sodium Selenite on Neurotoxicity Induced by Methylmercuric Chloride (유기수은의 신경독성에 대한 셀레늄의 보상작용)

  • Park, J.S.;Lee, H.M.;Chung, Y.;Shin, D.C.;Roh, J.H.;Moon, Y.H.
    • Journal of Preventive Medicine and Public Health
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    • v.25 no.1 s.37
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    • pp.13-25
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    • 1992
  • This study was conducted to investigate the mechanism of protective effect by sodium selenite in methylmercuric chloride neurotoxicity, increasing intracellular $Ca^{2+}$concentration of the neuron. Methylmercuric chloride of 3mg/kg of body weight was administered simultaneously with sodium selenite of 5mg/kg and pretreatment of sodium selenite via intraperitoneal injection to rats. Also, effect of methylmercuric chloride($25{\mu}M,\;50{\mu}M,\;100{\mu}M$) and sodium selenite($200{\mu}M$) on free intrasynaptosomal $Ca^{2+}$ concentration were studied using the fluorescent $Ca^{2+}$ indicator fura -2 in vitro. After the treatment, at 6, 24, and 48 hours later, mercury in the cerebral cortex, liver and kidney tissues, succlnic dehydrogenase activities, adenosin-5'-triphosphate concentration, acetylcholinesterase activities, and intracellular $Ca^{2+}$ concentration in the cerebral cortex were determined in vivo. Cerebral synaptosomes of rats were incubated with methylmercuric chloride and sodium selenite in Hepes buffer for 10 minutes and free intrasynaptosomal $Ca^{2+}$ concentration were measured with fura-2 in vitro. The results were summarized as follows ; 1. The combined administration of $CH_3HgCl$ and $Na_2SeO_3$ and pretreatment of $Na_2SeO_3$ according to time significantly more increased in the cerebral cortex and decreased in the liver, kidney mercury concentrations compared to the administration of $CH_3HgCl$ only. 2. The combined administration of $CH_3HgCl$ and $Na_2SeO_3$ and pretreatment of $Na_2SeO_3$ increased more succinic dehydrogenase and acetylcholinesterase activities compared to the administration of $CH_3HgCl$ only. Particularly pretreatment of $Na_2SeO_3$ significantly more compared to the administration of $CH_3HgCl$ only. The concentration of adenosine-5'-triphosphate in $Na_2SeO_3$ treatment groups revealed a favourable effect compared to the administration of $CH_3HgCl$ only. 3. Intracellular $Ca^{2+}$ concentration in administration of $CH_3HgCl$ only was increased significantly more than control group in all test hours but was increased significantly more at 48 hours only after treatment in combined administration of $CH_3HgCl$ and $Na_2SeO_3$ and pretreatment of $Na_2SeO_3$ according to time interval more decreased significantly intracellular $Ca^{2+}$ concentration compared to the administration of $CH_3HgCl$ only. 4. Free intrasynaptosomal $Ca^{2+}$ concentration in the combined administration of $CH_3HgCl$ and $Na_2SeO_3$ was decreased ($24%{\sim}40%$) significantly more than the administration of $CH_3HgCl$ only. From the above results, the specific dosage of $Na_2SeO_3$ decreased increment of intracellular $Ca^{2+}$ concentration induced by administration of $CH_3HgCl$. These findings suggest the protective mechanism of $Na_2SeO_3$ on the neurotoxicity of $CH_3HgCl$.

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Effects of Supplementary Copper Sources (Cu Sulfate, Cu-Methionine, Cu-Soy Proteinate) on the Performance Broiler Chickens (구리 공급원들(Cu Sulfate, Cu-Methionine, Cu-Soy Proteinate)의 첨가가 육계의 생산성에 미치는 영향)

  • Lee, Mun-Ku;Kim, Chan-Ho;Shin, Dong-Hun;Jung, Byoung-Yun;Paik, In-Kee
    • Korean Journal of Poultry Science
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    • v.38 no.2
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    • pp.121-128
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    • 2011
  • This study was conducted to investigate the effects of dietary supplementation of Cu-sulfate, Cu-methionine chelate (Cu-Met) and Cu-soy proteinate (Cu-SP) on the performance, blood parameters and mineral contents of muscle. It was conducted with a total of 1,000 one d old broilers chickens (Ross$^{(R)}$) which were assigned to four dietary treatments; Control, Cu sulfate (200 ppm Cu as $CuSO_4{\cdot}5H_2O$), Cu-Met (200 ppm Cu as Cu-methionine chelate), Cu-SP (200 ppm Cu as Cu-soy proteinate). There were significant differences (p<0.05) among treatments in weight gain. Weight gain of Cu treated groups were higher than the control during 3~5 wk. There were significant differences (p<0.05) among treatments in feed intake during 0~3 wk. Cu-Met was significantly (p<0.05) lower than the control but the differences among Cu treatments were not significant. There were significant differences (p<0.05) among treatments in feed conversion rate (FCR). Cu treated groups were lower than the control during the whole period. Production efficiency factor (PEF) was significantly higher (p<0.01) in Cu treated groups than the control. Nutrient availabilities of diets were not significantly different among the treatments. The count of white blood cell (WBC) and eosinophil (EO) were lower in Cu-SP treatment than in the control. Copper concentration in the liver was significantly (p<0.01) higher in Cu treated groups than the control. Zinc concentration in the breast and wing muscle was lower in Cu treated and that of leg muscle was higher in Cu-Met than the control. The result of this experiment showed that Cu supplementation at the level of 200 ppm as Cu sulfate, Cu-Met and Cu-SP improves weight gain (4~5 wk), FCR and PEF. Differences among Cu sources were not significant.

Regulation of Tumor Neceosis Factor-${\alpha}$ Receptors and Signal Transduction Pathways

  • Han, Hyung-Mee
    • Toxicological Research
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    • v.8 no.2
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    • pp.343-357
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    • 1992
  • Tumor necrosis factor-${\alpha}$(TNF), a polypeptide hormone secreted primarily by activated macrophages, was originally identified on the basis of its ability to cause hemorrhagic necrosis and tumor regression in vivo. Subsequently, TNF has been shown to be an important component of the host responses to infection and cancer and may mediate the wasting syndrome known as cachexia. These systemic actions of TNF are reflected in its diverse effects on target cells in vitro. TNF initiates its diverse cellular actions by binding to specific cell surface receptors. Although TNF receptors have been identified on most of animal cells, regulation of these receptors and the mechanisms which transduce TNF receptor binding into cellular responses are not well understood. Therefore, in the present study, the mechanisms how TNF receptors are being regulated and how TNF receptor binding is being transduced into cellular responses were investigated in rat liver plasma membranes (PM) and ME-180 human cervical carcinoma cell lines. $^{125}I$-TNF bound to high ($K_d=1.51{\pm}0.35nM$)affinity receptors in rat liver PM. Solubilization of PM with 1% Triton X-100 increased both high affinity (from $0.33{\pm}0.04\;to\;1.67{\pm}0.05$ pmoles/mg protein) and low affinity (from $1.92{\pm}0.16\;to\;7.57{\pm}0.50$ pmoles/mg protein) TNF binding without affecting the affinities for TNF, suggesting the presence of a large latent pool of TNF receptors. Affinity labeling of receptors whether from PM or solubilized PM resulted in cross-linking of $^{125}I$-TNF into $M_r$ 130 kDa, 90 kDa and 66kDa complexes. Thus, the properties of the latent TNF receptors were similar to those initially accessible to TNF. To determine if exposure of latent receptors is regulated by TNF, $^{125}I$-TNF binding to control and TNF-pretreated membranes were assayed. Specific binding was increased by pretreatment with TNF (P<0.05), demonstrating that hepatic PM contains latent TNF receptors whose exposure is promoted by TNF. Homologous up-regulation of TNF receptors may, in part, be responsible for sustained hepatic responsiveness during chronic exposure to TNF. As a next step, the post-receptor events induced by TNF were examined. Although the signal transduction pathways for TNF have not been delineated clearly, the actions of many other hormones are mediated by the reversible phosphorylation of specific enzymes or target proteins. The present study demonstrated that TNF induces phosphorylation of 28 kDa protein (p28). Two dimensional soidum dodecyl sulfate-polyacrylamide gel electrophoresis(SDS-PAGE) resolved the 28kDa phosphoprotein into two isoforms having pIs of 6.2 and 6.1. The pIs and relative molecular weight of p28 were consistent with those of a previously characterized mRNA cap binding protein. mRNA cap binding proteins are a class of translation initiation factors that recognize the 7-methylguanosine cap structure found on the 5' end of eukaryotic mRNAs. In vitro, these proteins are defined by their specific elution from affinity columns composed of 7-methylguanosine 5'-triphosphate($m^7$GTP)-Sepharose. Affinity purification of mRNA cap binding proteins from control and TNF treated ME-180 cells proved that TNF rapidly stimulates phosphorylation of an mRNA cap binding protein. Phosphorylation occurred in several cell types that are important in vitro models of TNF action. The mRNA cap binding protein phosphorylated in response to TNF treatment was purifice, sequenced, and identified as the proto-oncogene product eukaryotic initiation factor-4E(eIF-4E). These data show that phosphorylation of a key component of the cellular translational machinery is a common early event in the diverse cellular actions of TNF.

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Effects of Supplementation of Fat Sources, Ca and Mg on In Vitro Fermentation and the Performance of Finishing Hanwoo Bulls (지방의 공급형태와 Ca 및 Mg의 첨가가 In Vitro 발효 및 비육후기 한우의 성장성적에 미치는 영향)

  • Lee, H.G.;Lee, D.H.;Choi, N.J.;Lee, S.R.;Choi, Y.J.;Maeng, W.J.
    • Journal of Animal Science and Technology
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    • v.46 no.4
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    • pp.613-624
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    • 2004
  • This study was aimed at investigating the effect of fat supplementation with divalent ions such as MgO and $CaCl_2$ on 1) in vitro ruminal fermentation characteristics and insoluble fatty acid formation, and on 2) animal performance in finishing Hanwoo bulls. In in vitro trial, five different types of diets based on supplementation sources of fat and divalent ions, i.e. T=basal diet+4% tallow, T-Ca=T+0.5% $CaCl_2$, T-Mg=TA+0.5% MgO, T-MgCa = T +0.5% $CaCl_2$+0.5% MgO, T-caS =4% Ca salt tallow, were tested. Higher pH values were observed at 6 hr incubation(P<0.01) while higher amount of VFA were produced in diets 4 and 5 at 12 hr incubation(P<0.05). Nutrients(DM, OM, Crude protein and NDF) degradation tended to increase in divalent ions or Ca-salts treated tallow treatments compared with tallow treatment after 12 h. The amount of insoluble fatty acid increased by adding MgO or $CaCl_2$ to tallow or Ca soap tallow during incubation(P<0.05). In in vivo trial, thirty finishing Hanwoo(average BW 460kg) were divided into three groups based on fat sources and divalent ions, i.e. Control(EE 2.40), T-MgCa = control + tallow + $CaCl_2$ + MgO, T-CaS = control + Ca soap tallow (EE 5.30%). After feeding each diet for 80 days, average daily weight gain showed 0.89, 1.02, 1.17kg in diets 1, 2 and 3, respectively. The highest feed efficiency was observed(0.12) in diet 2 group, followed by diet 3 (0.10) and 1 groups(0.08; P < 0.05). In conclusion, the present results could be sununarized that the performance of Hanwoo bulls was improved by tallow with divalent ions without any negative effect on rumen fermentation.

Variation of Pinitol Content for Domestic Legume Species in Korea (국내 수집 두과식물의 부위별 pinitol 함량 변이)

  • Seo, Seung-Min;Jeong, Yeon-Shin;Hari, Dhakal Krisna;Shin, Dong-Hyun;Lee, In-Jung;Park, Eun-Sook;Lee, Jeong-Dong;Hwang, Young-Hyun
    • KOREAN JOURNAL OF CROP SCIENCE
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    • v.56 no.1
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    • pp.50-56
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    • 2011
  • This study was designed to investigate variation of pinitol content in different parts of seventeen legume species including silk tree (Albizia julibrissin). D-pinitol has been demonstrated to exert insulin-like and anti-inflammatory effects. These legumes were collected from Gyeongsangbuk-Do in Korea. Significant difference in pinitol content was observed among 17 different legume species. However, it was the highest in sericea lespedeza (Lespedeza cuneata). The highest pinitol content was observed in leaf followed by stem, pod shell, seed and root among plant parts. Legume plants which had higher pinitol content in leaves were chinese pea shrub, bastard indigo, wild cowpea and sericea lespedeza, having 59.9 mg/g, 62.2 mg/g, 69.6 mg/g and 65.4 mg/g, respectively. Stem of astragali radix showed the highest pinitol content among all leagumes, which was 34.0 mg/g. In case of root, kudzuvine showed the highest pinitol content followed by licorice and chinese pea shrub, which were 24.6 mg/g, 16.9 mg/g, and 16.5 mg/g, respectively. However, in the case of pod shell and seed, only lablab purpureus and sericea lespedeza showed the highest pinitol content 52.5 mg/g (for pod shell) and 24.9 mg/g (for seed), respectively. Concluding, the sericea lespedeza showed the highest total pinitol content of whole plant followed by chinese redbud, chinese pea shrub, bastard indigo and silk tree. Considering the pinitol content and harvesting yield, sericea lespedeza can be used as a practical medicinal herb.

Groundwater and Soil Environment of Plastic Film House Fields around Central Part of Korea (우리나라 중부지방의 시설원예 토양 및 지하수 환경)

  • Kim, Jin-Ho;Lee, Jong-Sik;Kim, Won-Il;Jung, Goo-Bok;Yun, Sun-Gang;Jung, Yeun-Tae;Kwun, Soon-Kuk
    • Korean Journal of Environmental Agriculture
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    • v.21 no.2
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    • pp.109-116
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    • 2002
  • The objective of this study was to know the qualities of soil and shallow groundwater in plastic film house fields around Central Part of Korea. The study was conducted at 11 sites in Suweon, Hwasung, Pyungtaek, Yongin and Chuncheon through May to August in 1999. Soil textures of plastic films house were mainly sandy loam or loam. Electric conductivity and organic matter content of surface soils mostly exceeded the critical levels for crop production. Average concentration of $NO_3-N$ in the sha]low groundwater was 19.1 mg/L, and it reached almost the limiting level of agricultural groundwater quality (20 mg/L). Moreover about 36% of survey sites exceeded the limiting level of agricultural groundwater quality. Sulfate concentrations also at some sites exceeded agricultural groundwater quality limit level (50 mg/L). Nitrate-N, one of the most important factors in the groundwater quality, had positive correlations with other ions in foundwater.

The Production of Sex Determined Cattle by Embryonic Sexing Using Fluorescence In Situ Hybridization Technique (FISH 기법을 이용한 소 수정란의 성감별과 산자 생산)

  • Sohn, S.H.;Park, H.
    • Proceedings of the Korean Society of Embryo Transfer Conference
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    • 2007.05a
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    • pp.39-50
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    • 2007
  • Sexing from bovine embryos fertilized in vitro implicates a possibility of the sex controlled cattle production. This study was carried out to produce the sex determined cattle through the embryonic sexing by fluorescence in situ hybridization (FISH) technique. FISH was achieved in in vitro fertilized bovine embryos using a bovine Y-specific DNA probe constructed from the btDYZ-1 sequence. Using this probe, a male-specific signal was detected on 100% of Y-chromosome bearing metaphase specimens. The analyzable rate of embryonic sexing by FISH technique was about 93% (365/393) regardless of embryonic stages. As tested single blastomere by FISH and then karyotype with their biopsied embryos, the accuracy of sex determination with FISH was 97.6%. We tried the embryo transfer with sex determined embryos on 15 cattle. Among them, the 5 cattle delivered calf with expected sex last year.

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Measurement of the Levels of IgG Subclasses Reactive to Salmonella typhi in the Sera of Patients with Typhoid Fever (장티푸스환자의 혈청내 Salmonella typhi에 대한 IgG subclass항체의 분포)

  • Kim, Young-Jung;Hwang, Eung-Soo;Kang, Jae-Seung;Cha, Chang-Yong;Chang, Woo-Hyun;Kim, Yoon-Won;Cho, Min-Ki;Min, Chang-Hong
    • The Journal of the Korean Society for Microbiology
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    • v.21 no.4
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    • pp.447-453
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    • 1986
  • To diagnose the typhoid fever rapidly and accurately in clinically suspected patients, the levels of IgG subclass antibody were measured by enzyme-linked immunosorbent assay(ELISA). With symptom, blood culture and agglutination test, tested persons were categorized into 6 groups as typhoid fever, FUO, paratyphi A or B, other bacterial infctions, cancers, and control. ELISA was performed on the polyvinyl chloride plates coated with killed whole cell($10^8\;cell/ml$) of S. typhi 0901W by poly-L-lysine applied as binding substance (and polyvinyl chloride as solid phase). The distribution of the level of IgG subclass antibodies in each group was analyzed and compared with other groups. The results obtained were summarized as follow: 1. The optimal dilution of the sera from patients with typhoid fever was 1:160, and those of the sheep anti-human IgG subclass and the peroxidase conjugated rabbit anti-sheep IgG were 1:4000 and 1:5000, respectively. 2. The absorbance levels of IgG subclass in the sera of typhoid fever patients were as follows; a) IgG1 value is $0.439{\pm}0.110$ b) IgG2 value is $0.416{\pm}0.165$ c) IgG3 value is $0.449{\pm}0.145$ d) IgG4 value is $0.525{\pm}0.154$ IgG subclass levels in the sera of typhoid patients were much higher than in control group and patient with paratyphi A or B as well as other infectious diseases. The sensitivity and the specificity in differential diagnosis of typhoid fever and other febrile diseases were 92% and 79% in the assay of IgG1 respectively, whereas those in the assay of IgG2 were 97% and 72%, respectively (above absorbance 0.3). 3. The absorbance levels of IgG subclass in the serial sera of typhiod fever patients tend to decrease to the level of absorbance 0.3 in 10 months from the onset of illness. 4. The order of absorbance levels of IgG subclass in the serum of each group were typhoid fever, paratyphi A or B, other infectious diseases, control and cancer. 5. For the serodiagnosis of typhoid fever against other febrile diseases, the sensitivity and the specificity in the assay of IgG2 activity were 76% and 93% in absorbance 0.4, respectively. 6. In the distribution of the level of each IgG subclass in the sera of FUO patients which were suspected of typhoid fever, the positive rate was ranged from 36% to 82%. This suggest that more than 50% of FUO patients are caused by S. typhi.

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Comparison of Volatile Organic Compound and Volatile Fatty Acid Concentration in Feces and Urine of Finishing Pigs (초지환원용 비육돈의 분과 뇨에 있어서 휘발성유기물과 휘발성지방산 농도 비교)

  • Cho, Sung Back;Hwang, Ok Hwa;Yang, Seung Hak;Kwag, Jeong Hoon;Choi, Dong Yun;Yang, Sung Bong;Kim, Doo Hwan;Park, Sung Kwon
    • Journal of The Korean Society of Grassland and Forage Science
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    • v.34 no.2
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    • pp.120-124
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    • 2014
  • This study was performed to compare the level of odorous compounds in feces and urine of finishing pigs. Feces and urine from 16 finishing pigs were separately collected for 28-d. Concentrations of volatile organic compound (VOC; phenols and indoles) and volatile fatty acid (VFA; SCFA and BCFA) were measured in feces and urine. Amount of phenols and p-cresol was higher (P<0.05) in urine than in feces. Urinal levels of phenols and p-cresol were 257.8 ppm and 250.9 ppm, and those of fecal phenols and p-cresol were 0.50 ppm and 0.05 ppm, respectively. There was no difference in concentration of indoles from feces (1.0 ppm) and urine (1.8 ppm). Short chain fatty acid (SCFA) level in urine was higher (P<0.05) than in feces showing 4,547 ppm and 863 ppm, respectively. Proportion of acetic acid to total SCFA was higher in urine (94%) than in feces (66%). However, level of branched fatty acid (BCFA) was greater in feces (118 ppm) compare to that of urine (87 ppm). Odorous compounds analyzed in the current study, phenols and SCFA, were contained more in urine than in feces. Greater amount of VFA is typically found in feces than in urine since it is generated in the large intestine. However, urine contained more VFA than feces in the current study. Therefore, it will be necessary to exploit odor reducing techniques especially for pig urine as grassland fertilizer.

MICROLEAKAGE OF MICROFILL AND FLOWABLE COMPOSITE RESINS IN CLASS V CAVITY AFTER LOAD CYCLING (Flowable 및 microfill 복합레진으로 충전된 제 5급와동에서 load cycling 전,후의 미세변연누출 비교)

  • Kang, Suk-Ho;Kim, Oh-Young;Oh, Myung-Hwan;Cho, Byeong-Hoon;Um, Chung-Moon;Kwon, Hyuk-Choon;Son, Ho-Hyun
    • Restorative Dentistry and Endodontics
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    • v.27 no.2
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    • pp.142-149
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    • 2002
  • Low-viscosity composite resins may produce better sealed margins than stiffer compositions (KempScholte and Davidson, 1988: Crim, 1989). Plowable composites have been recommended for use in Class V cavities but it is also controversial because of its high rates of shrinkage. On the other hand, in the study comparing elastic moduli and leakage, the microfill had the least leakage (Rundle et at. 1997) Furthermore, in the 1996 survey of the Reality Editorial Team, microfills were the clear choice for abfraction lesions. The purpose of this study was to evaluate the microleakage of 6 compostite resins (2 hybrids, 2 microfills, and 2 flowable composites) with and without load cycling. Notch-shaped Class V cavities were prepared on buccal surface of 180 extracted human upper premolars on cementum margin. The teeth were randomly divided into non-load cycling group (group 1) and load cycling group (group 2) of 90 teeth each. The experimental teeth of each group were randomly divided into 6 subgroups of 15 samples. All preparations were etched, and Single bond was applied. Preparations were restored with the following materials (n=15) : hybrid composite resin [Z250(3M Dental Products Inc. St. Paul, USA), Denfil(Vericom, Ahnyang, Korea)], microfill [Heliomolar RO(Vivadent, Schaan, Liechtenstein), Micronew(Bisco Inc. Schaumburg, IL, USA)], and flowable composite[AeliteFlo(Bisco Inc. Schaumburg, IL, USA), Revolution(Kerr Corp. Orange, CA, USA)]. Teeth of group 2 were subjected to occlusal load (100N for 50,000 cycles) using chewing simulator(MTS 858 Mini Bionix II system, MTS Systems Corp. Minn. USA). All samples were coated with nail polish 1mm short of the restoration, placed in 2% methylene blue for 24 hours, and sectioned with a diamond wheel. Enamel and dentin/cementum margins were analyzed for microleakage on a sclale of 0 (no leakage) to 3 (3/3 of wall). Results were statistically analyzed by Kruscal-Wallis One way analysis, Mann-Whitney U-test, and Student-Newmann-Keuls method. (p = 0.05) Results : 1. There was significantly less microleage in enamel margins than dentinal margins of all groups (p<0.05) 2. There was no significant between six composite resin in enamel margin of group 1. 3. In dentin margin of group 1, flowable composite had more microleakage than others but not of significant differences. 4. there was no significant difference between six composite resin in enamel margin of group 2. 5. In dentin margin of group 2, the microleakage were R>A =H=M>D>Z. But there was no significant differences. 6. In enamel margins, load cycling did not affect the marginal microleakage in significant degree. 7. In enamel margins, load cycling did affect the marginal microleakage only in Revolution. (p<0.05).