• Title/Summary/Keyword: Centrifugation, density gradient

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Use of enzyme-linked immunosorbent assay (ELISA) for detection of toxoplasmosis in dogs (ELISA 법을 이용한 개 톡소플라즈마병의 조기진단에 관한 연구)

  • Suh, Myung-deuk;Joo, Hoo-don;Lee, Byung-hoon
    • Korean Journal of Veterinary Research
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    • v.31 no.4
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    • pp.491-500
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    • 1991
  • This study was conducted to detect the serum antibodies in the experimentally toxoplasma infected dogs and street dogs by use the of an enzyme-linked immunosorbent assay (ELISA). And this test was performed on the polystylene microplate by coating with the tachyzoites soluble antigen of T gondii (RH strain), incubated with sera diluted then, added with HPO-conjugated rabbit anti-dog IgG and o-phenylenediamine used as a substrate. Tachyzoites of T gondii harvested from mouse peritoneal cavity were purified by 30, 40 and 50% Percoll density gradient centrifugation and used as the source of antigen. The results obtained were summarized as follows; 1. The highest ratio of positive to negative (P/N ratio) was obtained at the level of $l{\mu}g/ml$ protein concentration of antigen with the 1/4000 dilution of the conjugate measured by checker-board titration. It was regarded as the optimum concentration of the antigen and conjugate. 2. Cut-off value in this IgG ELISA was 0.375 that was determined by mean absorbance (at 492nm) of IFA negative serum added with the dauble value of the standard deviation $(mean{\pm}2S.D.)$. 3. Serum ELISA IgG antibodies to T gondii in the exyerimentally infected dogs were detected firstly at the Week 3 after inoculation and the highest titer was recognized at the Week 4, 5 and 6 after inoculation. 4. Stability of the antigen absorbed in the microplates that were preserved at $4^{\circ}C$ and $-25^{\circ}C$ separately were prolonged up to 3 weeks and 10 weeks at $4^{\circ}C$ and $-25^{\circ}C$, respectively. However the reproducibility was not reliable after the preservation of 4 weeks and longer. 5. Positive rate of the specific antibodies in 312 test sera was 28.5% and there was no significant differences between the male (27.8%) and female (29.5%), respectively. 6. The IgG ELISA was proved to be a specific procedure for the detection of antibodies to canine toxoplasma infection and also evaluated as a screening test for the large scale of test samples in laboratory.

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Effects of lycopene on number and function of human peripheral blood endothelial progenitor cells cultivated with high glucose

  • Zeng, Yao-Chi;Mu, Gui-Ping;Huang, Shu-Fen;Zeng, Xue-Hui;Cheng, Hong;Li, Zhong-Xin
    • Nutrition Research and Practice
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    • v.8 no.4
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    • pp.368-376
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    • 2014
  • BACKGROUND/OBJECTIVES: The objectives of this study were to investigate the effects of lycopene on the migration, adhesion, tube formation capacity, and p38 mitogen-activated protein kinase (p38 MAPK) activity of endothelial progenitor cells (EPCs) cultivated with high glucose (HG) and as well as explore the mechanism behind the protective effects of lycopene on peripheral blood EPCs. MATERIALS/METHODS: Mononuclear cells were isolated from human peripheral blood by Ficoll density gradient centrifugation. EPCs were identified after induction of cellular differentiation. Third generation EPCs were incubated with HG (33 mmol/L) or 10, 30, and $50{\mu}g/mL$ of lycopene plus HG. MTT assay and flow cytometry were performed to assess proliferation and apoptosis of EPCs. EPC migration was assessed by MTT assay with a modified boyden chamber. Adhesion assay was performed by replating EPCs on fibronectin-coated dishes, after which adherent cells were counted. In vitro vasculogenesis activity was assayed by Madrigal network formation assay. Western blotting was performed to analyze protein expression of both phosphorylated and non-phosphorylated p38 MAPK. RESULTS: The proliferation, migration, adhesion, and in vitro vasculogenesis capacity of EPCs treated with 10, 30, and $50{\mu}g/mL$ of lycopene plus HG were all significantly higher comapred to the HG group (P < 0.05). Rates of apoptosis were also significantly lower than that of the HG group. Moreover, lycopene blocked phosphorylation of p38 MAPK in EPCs (P < 0.05). To confirm the causal relationship between MAPK inhibition and the protective effects of lycopene against HG-induced cellular injury, we treated cells with SB203580, a phosphorylation inhibitor. The inhibitor significantly inhibited HG-induced EPC injury. CONCLUSIONS: Lycopene promotes proliferation, migration, adhesion, and in vitro vasculogenesis capacity as well as reduces apoptosis of EPCs. Further, the underlying molecular mechanism of the protective effects of lycopene against HG-induced EPC injury may involve the p38 MAPK signal transduction pathway. Specifically, lycopene was shown to inhibit HG-induced EPC injury by inhibiting p38 MAPKs.

EFFECT OF PLATELET-RICH PLASMA ON AUTOGENOUS BONE GRAFT FOR BONE FORMATION IN RABBIT (가토 하악골 결손부의 자가골 이식시 혈소판 풍부혈장이 골형성 촉진에 미치는 영향에 관한 연구)

  • Jeon, Min-Su;Kim, Bo-Gyun;Song, Jun-Ho;Yeon, Byong-Moo;Lee, Young-Woo;Noh, Kyung-Lok;Kim, Da-Young;Pang, Ean-O;Kim, Jun-Hyun;Nam, Jeong-Hun;Gang, Tae-In;Lim, Sung-Chul;Park, Young-Ju
    • Maxillofacial Plastic and Reconstructive Surgery
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    • v.30 no.2
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    • pp.158-164
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    • 2008
  • Purpose : Recently, various materials were developed for enhancing bone formation capacity. Platelet rich plasma(PRP) is an autologous source with several growth factors and obtained by sequestering and concentrating platelets by gradient density centrifugation. This study was to evaluate the effect of PRP on healing of grafted bone. Materials and methods : Two blood samples were obtained and analysed for measuring platelet counts of normal blood and PRP. In experimental group, two defects of mandibular bone, 10mm in diameter and 4.0mm deep, were created in the mandible and immediately grafted with autogenous bone chips mixed with PRP. In control group, same bone defects were prepared and grafted with autogenous bone chips. Gelform was used for carrier of PRP. 2 weeks, 4 weeks, 8 weeks later, each group was evaluated with histologi-cal and histomorphometric analyses. Results : According to histological observation, experimental group was showed more anastomosing newly-formed woven bone having osteoblastic activation than control group. According to histomorphometric analysis, there were 9.11% more newly-formed bone volume in experimental group than control group at 2 weeks, 7.91% more at 4 weeks, 20.08% more at 8 weeks. Conclusion: Our results demonstrated PRP in autogenous bone graft could enhance the bone formation.

Studies on the Factors Influencing the Transformation in Escherichia with pBR322 DNA (Escherichia coli의 pBR322 DNA 형질전환에 관여하는 인자에 관한 연구)

  • Yoo, Han-sang;Mah, Jum-sool
    • Korean Journal of Veterinary Research
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    • v.24 no.1
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    • pp.40-49
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    • 1984
  • To investigate the factors influencing the artifical transformation in Escherichia coli, E. coli C600 was transformed by pBR322 DNA with tetracycline and ampicillin resistant gene purified by CsCl-Etbr equilibrium density gradient centrifugation from E.coli HB 101. The influencing factors in the transformation such as concentration of calcium chloride, time of ice incubation, temperature and time of heat shock, time of gene expression, effects of plasmid DNA concentration and adding time were examined in these experiments. The results obtained were as follows; 1. The highest transformation frequency was observed in the treatments of 100 mM $CaCl_2$ before heat shock and the treatment of $CaCl_2$ was essential step in the process of E. coli transformation. 2. The highest transformation frequency was observed in the treatment of heat shock at $42^{\circ}C$ for 4 min. or $37^{\circ}C$ for 6 min., but the prolonged heat shock resulted a decreased transformation frequency. 3. Treatments of ice incubation at $0^{\circ}C$ for 45 min. before heat stocks or at $0^{\circ}C$ for 30min. after heat shock resulted an increased transformation frequency. 4. There was a linear relationship between DNA concentration and transformation frequency at the concentration of $8{\times}10^3$ recipient cells. The highest transformation frequency reached in carte of 7 mcg of donor DNA, but above 1 mcg of DNA concentration, transformation frequency was not remarkably increased. Addition of donor DNA just after the treatment of $CaCl_2$ was the best. 5. The best condition of gene expression at $37^{\circ}C$ were 40min. for TC-resistant gene and 100min. for AP-resistant gene. TC-resistant gene was higher in the transformation frequency and faster in the gene expression time than AP-resistant gene. In these results, the best conditions for the transformation of E. coli C 600 with pBR322 DNA were: treatment with 100mM $CaCl_2$, ice incubation at $0^{\circ}C$ for 45 min, heat shock at $42^{\circ}C$ for 4 min., 30 min. of ice incubation and incubation at $37^{\circ}C$ for 100min. for gene expression in that order.

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Occurrence of Enterocytozoon bieneusi in Korean Native Cattle Examined by Light Microscopic and Molecular Methods (광학 현미경 및 분자생물학적 방법을 적용한 한우의 Enterocytozoon bieneusi 역학조사)

  • Lee, John-Hwa;Kim, Nam-Soo;Jeon, Byung-Woo;Son, Hwa-Young;Ryu, Si-Yun;Shin, Hyun-Jin;Park, Jie-Yeun;Kim, Hyeon-Cheol;Hur, Jin;Cho, Jeong-Gon;Park, Bae-Keun
    • Journal of Veterinary Clinics
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    • v.27 no.1
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    • pp.1-5
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    • 2010
  • Enterocytozoon bieneusi, a microsporidian species, has emerged as an opportunistic pathogen in AIDS patients. This organism has also been identified in a wide range of animals, and the zoonotic potential of human infections is of particular interest. This study revealed that this organism was found with relatively high prevalence in feces of asymptomatic cattle in Korea. Fecal specimens were obtained from a total of 1,720 cattle in a slaughterhouse located in Chungnam province, Daejeon city and Chonbuk province. After removal of fecal debris by sieving and density gradient centrifugation, samples were examined by microscopic examination and then nested polymerase chain reaction (PCR). Microscopic examination with the modified trichrome staining for the fecal specimens revealed 194 (11.28%) positive calves for microsporidia spore. PCR using the specific primer for E. bieneusi revealed 79 (4.59%) positive calves. The infection ratio of microsporidia was higher in March than other season.

Treatment with Rutin - A Therapeutic Strategy for Neutrophil-Mediated Inflammatory and Autoimmune Diseases - Anti-inflammatory Effects of Rutin on Neutrophils -

  • Nikfarjam, Bahareh Abd;Adineh, Mohtaram;Hajiali, Farid;Nassiri-Asl, Marjan
    • Journal of Pharmacopuncture
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    • v.20 no.1
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    • pp.52-56
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    • 2017
  • Objectives: Neutrophils represent the front line of human defense against infections. Immediately after stimulation, neutrophilic enzymes are activated and produce toxic mediators such as pro-inflammatory cytokines, nitric oxide (NO) and myeloperoxidase (MPO). These mediators can be toxic not only to infectious agents but also to host tissues. Because flavonoids exhibit antioxidant and anti-inflammatory effects, they are subjects of interest for pharmacological modulation of inflammation. In the present study, the effects of rutin on stimulus-induced NO and tumor necrosis factor $(TNF)-{\alpha}$ productions and MPO activity in human neutrophils were investigated. Methods: Human peripheral blood neutrophils were isolated using Ficoll-Hypaque density gradient centrifugation coupled with dextran T500 sedimentation. The cell preparations containing > 98% granulocytes were determined by morphological examination through Giemsa staining. Neutrophils were cultured in complete Roswell Park Memorial Institute (RPMI) medium, pre-incubated with or without rutin ($25{\mu}M$) for 45 minutes, and stimulated with phorbol 12-myristate 13-acetate (PMA). Then, the $TNF-{\alpha}$, NO and MPO productions were analyzed using enzyme-linked immunosorbent assay (ELISA), Griess Reagent, and MPO assay kits, respectively. Also, the viability of human neutrophils was assessed using tetrazolium salt 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT), and neutrophils were treated with various concentrations of rutin ($1-100{\mu}M$), after which MTT was appended and incubated at $37^{\circ}C$ for 4 hour. Results: Rutin at concentrations up to $100{\mu}M$ did not affect neutrophil viability during the 4-hour incubation period. Rutin significantly decreased the NO and $TNF-{\alpha}$ productions in human peripheral blood neutrophils compared to PMA-control cells (P < 0.001). Also, MPO activity was significantly reduced by rutin (P < 0.001). Conclusion: In this in vitro study, rutin had an anti-inflammatory effect due to its inhibiting NO and $TNF-{\alpha}$ productions, as well as MPO activity, in activated human neutrophils. Treatment with rutin may be considered as a therapeutic strategy for neutrophil-mediated inflammatory/autoimmune diseases.

Studies on the Development of Photoreceptor in the Nonchromatophore Organisms (III) -Light- Induced Mitochondrial ATP Synthase in the Lentinus edodes (Berk.) Sing.- (무흡광 색소 생물의 감광수용체 개발 연구(III) -표고버섯 중의 광감응성 Mitochondrial ATP Synthase-)

  • Min, Tae-Jin;Lee, Wan-Gie;Park, Sang-Shin
    • The Korean Journal of Mycology
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    • v.17 no.2
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    • pp.91-98
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    • 1989
  • Mitochondria in the L. edodes was separated and purified by stepped sucrose density gradient centrifugation. The activity of mitochondrial ATP synthase has been investigated during various illumination times at each wavelength within the range of 400 nm to 700 nm. The stimulation of above activity increased by two times compared with nonilluminated control group when the illumination was given for 15 seconds at 470 nm wavelength. The optimal pH and temperature of this light-induced mitochondrial ATP synthase were 7.5 and $54^{\circ}C$, respectively. The activity of this enzyme increased by 26%, 25% and 14%, respectively, when there were 1 mmole $Fe^{3+}$, 0.5 mmole $Fe^{2+}$, and 5 mmole ${SO_4}^{2-}$ ion, and was inhibited by 5 mmole $Co^{2+}$, 5 mmole $Mn^{2+}$, 1 mmole $Ca^{2+}$, 0.1 mmole $Na^+$, 5 mmole $CN^-$, and 0.1 mmole ${CO_3}^{2-}$ ion. But $Na^+$ and $K^+$ ion did not affect the activity of enzyme.

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Characteristics and Pathogenicity of Hyphantria cunea Nuclear Polyhedrosis Virus (Hyphantria cunea Nuclear Polyhedrosis Virus의 특성 및 병원성)

  • Lee, Keun-Kwang;Kim, Myung-Kon;Park, Il-Woong
    • Applied Biological Chemistry
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    • v.38 no.5
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    • pp.435-439
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    • 1995
  • Some characteristics and pathogenicity of Hyphantria cunea nuclear polyhedrosis virus (HcNPV), a potential microbial pesticide was studied. H. cunea NPV replicated in the nucleus of S. frugiperda cells cultured in the TNMFH medium. In case of virus infected cell, prepolyhedra formation was observed at 24hrs post-infection. At 48 hrs post-infection, Most of the infected cell contained many mature polyhedra which were released into culture media 72 hrs post-infection, with the cells grown in suspension culture, pH of the culture medium increased during the virus replication: the pH of fresh medium was 6.35 and rose to 6.77 within 120 hrs. Polyhedra formed a band in linear density gradient of sucrose by centrifugation, which co-sedimented with $50{\sim}55%$ sucrose. The shape of the purified polyhedra was mostly tetragonal hexahedron and its size was about $2.5{\mu}m$. Electron microscopy and phase contrast microscopy showed that many bundled nucleocapsids were occluded in mature polyhedra at 48 hrs post infection. H. cunea larvae infected with NPV showed a higher motality in the second and third instar than in the fourth instar. Death rate of H. cunea larvae in the second and third instar fed with leaves coated with $1.5{\times}10^{9}{\sim}l.5{\times}10^{7}PIBs/ml$ reached more than 90%.

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Partial Characterization of Physicochemical and Kinetic Properties of $Ca^{++}-ATPase$ System in Luteal Membranes (황체막에서의 $Ca^{++}-ATPase$의 특성)

  • Choi, Gyu-Bog;Koo, Bon-Sook;Kim, In-Kyo
    • The Korean Journal of Physiology
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    • v.20 no.2
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    • pp.257-270
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    • 1986
  • It has been reported that the luteal function may be regulated by the intracellular calcium in luteal cells (Higuchi et al, 1976; Dorflinger et at, 1984; Gore and Behrman, 1984) which is adjusted partially by $Ca^{++}-ATPase$ activities in luteal cell membranes (Verma and Pennistion, 1981). However, the physicochemical and kinetic properties of $Ca^{++}-ATPase$ in luteal membranes were not fully characterized. This study was, therefore, undertaken to partially characterize the physicochemical and kinetic properties of $Ca^{++}-ATPase$ system in luteal membranes and microsomal fractions, known as an one of the major $Ca^{++}$ storge sites (Moore and Pastan, 1978), from the highly luteinized ovary Highly luteinized ovaries were obtained from PMSG-hCG injected immautre female rats. Light membrane and heavy membrane fractions and microsomal fractions were prepared by the differential and discontinuous sucrose density gradient centrifugation method desribed by Bramley and Ryan (1980). Light membrane and heavy membrane fractions and microsomal fractions from highly luteinized ovaries are composed of the two different kinds of $Ca^{++}-ATPase$ system. One is the high affinity $Ca^{++}-ATPase$ which is activated in low $Ca^{++}$ concentration (Km, 10-30 nM), the other is low affinity $Ca^{++}-ATPase$ activated in higher $Ca^{++}$ concentration $(K_{1/2},\;40\;{\mu}M)$. At certain $Ca^{++}$ concentrations, activities of high and low affinity $Ca^{++}-ATPase$ are the highest in light membrane fractions and are the lowest in microsomal fractions. It appeares that high affinity $Ca^{++}-ATPase$ system have 2 binding sites for ATP (Hill's coefficient; around 2 in all membrane fractions measured) and the positive cooperativity of ATP bindings obviously existed in each membrane fractions. The optimum pH for high affinity $Ca^{++}-ATPase$ activation is around S in all membrane fractions measured. The lipid phase transition temperature measured by Arrhenius plots of high affinity $Ca^{++}-ATPase$ activity is around $25^{\circ}C$. The activation energies of high affinity $Ca^{++}-ATPase$ below the transition temperature are similar in each membrane fractions, but at the above transition temperature, it is the hightest in heavy membrane fractions and the lowest in microsomal fractions. According to the above results, it is suggested that intracellular $Ca^{++}$ level, which may regulate the luteal function, may be adjusted primarily by the high affinity $Ca^{++}-ATPase$ system activated in intracellular $Ca^{++}$ concentration range $(below\;0.1\;{\mu}M)$.

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Purification and Pathogenicity of the Granulosis Viruses of Common Cabbage Worm, Pieris rapae and Pieris brassicae (배추흰나비 과립병바이러스의 정제 및 병원성)

  • 류강선;김근영;강석원
    • Korean journal of applied entomology
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    • v.30 no.3
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    • pp.187-195
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    • 1991
  • This study was carried out to acquire some basic biological informations on the granulosis virus (GV) of Pieris rapae and Pieris brassicae. Purified fractions of GV capsules in an sucrose density gradient centrifugation yielded on homogenous and sharp peak without a shoulder. Electron microscopy revealed that GV capsules were mostly ovalglove in shape. P. rapae and P. rapae GV isolated from P. rapae comprised granules($396\pm38\times238\pm25nm$ for P. rapae GV. $375\pm40\times255\pm28nm$ for P. brassicae GV) which contained single virus particle. The virus particles were 250- $275{\times}63$ -73nm for P. rapae GV and 243-250 $\times$ 63-75nm for P. brassicae GV containing a nucleocapsid 225 $\times$ 31nm for P. rapae, 225 $\times$ 29nm for P. brassicae within an envelope. The virulent difference between the two viruses was very small in their virulence for P. rapae larvae showing the $LC_{50}$( -log) with 5.5673 for P. rapae GV and 5.8104 for P. brassicae GV. Also the $LT_{50}$ of the 3rd instar P. rapae larvae against $10^{-6}$ inoculum was 8.17 days for P. rapae GV and 7.16 days for P. brassicae GV.

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