• Title/Summary/Keyword: bio assay

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Effects of PEGylated scFv Antibodies against Plasmodium vivax Duffy Binding Protein on the Biological Activity and Stability In Vitro

  • Kim, So-Hee;Lee, Yong-Seok;Hwang, Seung-Young;Bae, Gun-Won;Nho, Kwang;Kang, Se-Won;Kwak, Yee-Gyung;Moon, Chi-Sook;Han, Yeon-Soo;Kim, Tae-Yun;Kho, Weon-Gyu
    • Journal of Microbiology and Biotechnology
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    • v.17 no.10
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    • pp.1670-1674
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    • 2007
  • Duffy binding protein (DBP) plays a critical role in Plasmodium vivax invasion of human red blood cells. We previously reported a single-chain antibody fragment (scFv) that was specific to P. vivax DBP (PvDBP). However, the stabilization and the half-life of scFvs have not been studied. Here, we investigated the effect of PEGylated scFvs on their biological activity and stability in vitro. SDS-PAGE analysis showed that three clones (SFDBII-12, -58, and -92) were formed as monomers (about 70 kDa) with PEGylation. Clone SFDBII-58 gave the highest yield of PEGylated scFv. Binding analysis using BIAcore between DBP and scFv showed that both SFDBII-12 and -58 were decreased approximately by two folds at the level of binding affinity to DBP after PEGylation. However, the SFDBII-92 clone still showed a relatively high level of binding affinity ($K_D=1.02{\times}10^{-7}\;M$). Binding inhibition assay showed that PEGylated scFv was still able to competitively bind the PvDBP and playa critical role in inhibiting the interactions between PvDBP protein expressed on the surface of Cos-7 cells and Duffy receptor on the surface of erythrocytes. When both scFvs and their PEGylated counterparts were exposed to trypsin, scFv was completely degraded only after 24 h, whereas 35% of PEGylated scFvs remained intact, maintaining their stability against the proteolytic attack of trypsin until 72 h. Taken together, these results suggest that the PEGylated scFvs retain their stability against proteolytic enzymes in vivo, with no significant loss in their binding affinity to target antigen, DBP.

Expression of $interferon$ $regulatory$ factor-1 in the mouse cumulus-oocyte complex is negatively related with oocyte maturation

  • Kim, Yun-Sun;Kim, Eun-Young;Moon, Ji-Sook;Yoon, Tae-Ki;Lee, Woo-Sik;Lee, Kyung-Ah
    • Clinical and Experimental Reproductive Medicine
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    • v.38 no.4
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    • pp.193-202
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    • 2011
  • Objective: We found previously that $interferon$ $regulatory$ factor ($Irf$)-1 is a germinal vesicle (GV)-selective gene that highly expressed in GV as compared to metaphase II oocytes. To our knowledge, the function of $Irf-1$ in oocytes has yet to be examined. The present study was conducted to determine the relationship between retinoic acid (RA) and RA-mediated expression of $Irf-1$ and the mouse oocyte maturation. Methods: Immature cumulus-oocyte-complexes (COCs) were collected from 17-day-old female mice and cultured $in$ $vitro$ for 16 hours in the presence of varying concentrations of RA (0-10 ${\mu}M$). Rate of oocyte maturation and activation was measured. Gene expression was measured by quantitative real-time reverse transcription-polymerase chain reaction (RT-PCR) and cytokine secretion in the medium was measured by Bio-Plex analysis. Apoptosis was analyzed by terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) assay. Results: The rates of oocyte maturation to metaphase II and oocyte activation increased significantly with RA treatment (10 nM-1 ${\mu}M$). With 100 nM RA treatment, lowest level of $Irf-1$ mRNA and cumulus cell's apoptosis was found. Among 23 cytokines measured by Bio-Plex system, the substantial changes in secretion of tumor necrosis factor-${\alpha}$, macrophage inflammatory protein-$1{\beta}$, eotaxin and interleukin-12 (p40) from COCs in response to RA were detected. Conclusion: We concluded that the maturation of oocytes and $Irf-1$ expression are negatively correlated, and RA enhances the developmental competence of mouse immature oocytes $in$ $vitro$ by suppressing apoptosis of cumulus cells. Using a mouse model, results of the present study provide insights into improved culture conditions for $in$ $vitro$ oocyte maturation and relevant cytokine production and secretion in assisted reproductive technology.

Insect Resistance of Tobacco Plant Expressing CpBV-ELP1 Derived from a Polydnavirus (폴리드나바이러스 유래 CpBV-ELP1 발현 담배의 내충성)

  • Kim, Eunseong;Kim, Yonggyun
    • Korean journal of applied entomology
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    • v.56 no.1
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    • pp.19-28
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    • 2017
  • Polydnaviruses (PDVs) are a group of double-stranded DNA viruses symbiotic to some endoparasitoid wasps. Cotesia plutellae bracovirus (CpBV) is a PDV symbiotic to an endoparasitoid wasp, C. plutellae, parasitizing young larvae of Plutella xylostella. An early expressed gene, CpBV-ELP1, plays an important role in the parasitism by suppressing host cellular immunity by its cytotoxic activity against hemocytes. This study aimed to test its oral toxicity against insect pest by expressing it in a recombinant tobacco plant. A recombinant CpBV-ELP1 protein was produced using a baculovirus expression system and secreted to cell culture medium. The cell cultured media were used to purify CpBV-ELP1 by a sequential array of purification steps: ammonium sulfate fractionation, size exclusion chromatography, and ion exchange chromatography. Purified rCpBV-ELP1 exhibited a significant cytotoxicity against Spodoptera exigua hemocytes. CpBV-ELP1 was highly toxic to the fifth instar larvae of S. exigua by injection to hemocoel. It also showed a significant oral toxicity to fifth instar larvae of S. exigua by a leaf-dipping assay. CpBV-ELP1 was cloned into pBI121 vector under CaMV 35S promoter with opaline synthase terminator. Resulting recombinant vector (pBI121-ELP1) was used to transform Agrobacterium tumefaciens LBA4404. The recombinant bacteria were then used to induce callus of a tobacco (Nicotiana tabacum Xanthi) leaves and subsequent generation (T1) plants were selected. T1 generation tobacco plants expressing CpBV-ELP1 gave significant insecticidal activities against S. exigua larvae. These results suggest that CpBV-ELP1 gene can be used to control insect pests by constructing transgenic crops.

Simultaneous Detection of Staphylococcus aureus, Salmonella enterica subsp., Vibrio parahaemolyticus by Multiplex Polymerase Chain Reaction (Multiplex Polymerase Chain Reaction(PCR)법을 이용한 Staphylococcus aureus, Salmonella enterica subsp., Vibrio parahaemolyticus의 다중동시검출)

  • Jeong, Yoo-Seok;Jung, Hee-Kyoung;Jeon, Won-Bae;Seo, Hwa-Jung;Hong, Joo-Heon
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.39 no.4
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    • pp.595-601
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    • 2010
  • This study was conducted to detect and identify Staphylococcus aureus, Vibrio parahaemolyticus, and Salmonella enterica subsp. using simultaneous multiplex polymerase chain reaction (multiplex PCR) assay. 23S rRNA partial gene (S. aureus), tox R gene (V. parahaemolyticus), and inv A gene (S. enterica subsp.) as diagnostic marker gene were suggested, and their amplicon sizes were 482 bp, 368 bp, and 284 bp, respectively. Non specific amplicons by STA-5F/STA-5R primer, ToxR-F/ToxR-R primer, and 139/141 primer were not observed in genomic DNA of pathogen bacteria as Bacillus cereus, Listeria monocytogenes, Escherichia coli, Proteus vulgaris, Streptococcus pyogenes, Candida albicans, and Shigella sonnei. The extracted crude DNA of targeted bacteria was detected as PCR template successfully. The detection limits were $10^5\sim10^4$ CFU/mL and 10 pg of purified genomic DNA of S. aureus, V. parahaemolyticus, and S. enterica subsp. by using simultaneous multiplex PCR.

Gene Structure and Altered mRNA Expression of Metallothionein in Response to Metal Exposure and Thermal Stress in Miho Spine Loach Cobitis choii (Cobitidae; Cypriniformes) (미호종개 metallothionein 유전자의 구조 및 중금속 노출과 고온 자극에 대한 MT mRNA의 발현 특징 분석)

  • Lee, Sang-Yoon;Nam, Yoon-Kwon
    • Korean Journal of Ichthyology
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    • v.23 no.1
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    • pp.61-69
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    • 2011
  • Gene and promoter structures of metallothionein(MT) from Miho spine loach (Cobitis choii; Cypriniformes) were characterized, and the transcriptional responses to experimental exposures to heavy metals and heat stress were examined. The C. choii metallothionein displayed well-conserved features of teleostean metallothioneins at gDNA, mRNA and amino acid levels. Bioinformatic analysis predicted that the C. choii MT regulatory region potentially possessed various motifs or elements targeted by various transcription factors associated with metal-coordinating regulation (e.g., metal transcription factor-1), immune responses (e.g., nuclear factor kappa B), and thermal modulations (e.g., heat shock factor). Acute heavy-metal exposures to 0.5 or $1.0\;{\mu}M$ of cadmium (Cd), copper (Cu), manganese (Mn), nickel (Ni) or zinc (Zn) showed that MT transcription was significantly stimulated by Cd (9.6-fold relative to non-exposed control) and Cu (10.4-fold), only moderately by Mn (2.4-fold), but hardly by Ni and Zn. Elevation of water temperature from $25^{\circ}C$ to $31^{\circ}C$ caused a rapid modulation of MT mRNAs toward upregulation to 9.5-fold; however, afterward the elevated mRNA level slightly decreased during further incubation at $31^{\circ}C$ for 6 h. Results from this study suggest that MT-based expression assay could be a useful basis for better understanding the metal- and/or heat-caused stresses in this endangered fish species.

Evaluation of Physical Properties and Biocompatibility of HA-Dex Fusion Hydrogel Patch for Atopic Healing Ability (HA-Dex 융복합 하이드로겔 패치의 아토피 치유 능력에 대한 물리적 특성 및 생체 적합성 평가)

  • Hong, Gyeong Sik;Choi, Jeong Yeon;Choi, Jin Hyun
    • Journal of the Society of Cosmetic Scientists of Korea
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    • v.46 no.3
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    • pp.219-229
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    • 2020
  • Recently, since atopic dermatitis is sensitive to skin irritation, it has been suggested that the development of a patch that can effectively exhibit adhesion and absorption to a specific local area while minimizing skin irritation, and capable of appropriate drug release should be given priority. In this study, we tried to develop a hydrogel patch that minimizes skin irritation, adheres effectively to a specific area, and promotes absorption. The atopic patch was formulated into a super-absorbent hydrogel sheet using a freeze drying method. Cell viability assay was carried out using keratinocytes (HaCaT cell) and fibroblasts (L929 cells). In order to investigate the physical properties, FT-IR, FE-SEM, porosity analysis and swelling behavior were investigated. As a result, the newly prepared HA-Dex hydrogel patch was verified by biocompatibility and physical evaluation. In addition, the manufactured hydrogel patch has sufficient moisture absorption capacity and can relieve itching of atopic skin, and is expected to be applied to various drug delivery products for the treatment of atopic dermatitis in the future.

Effects of Yucca Extract and (or) Far Infrared Emitted Materials Supplementation on the Growth Performance, Serum Characteristics and Ammonia Production of Growing and Finishing Pigs

  • Hong, J.W.;Kim, I.H.;Moon, T.H.;Kwon, O.S.;Lee, S.H.;Kim, Y.G.
    • Asian-Australasian Journal of Animal Sciences
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    • v.14 no.9
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    • pp.1299-1303
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    • 2001
  • For the Exp. 1, a total of fifty four crossbred [(Duroc Yorkshire)${\times}$Landrace] pigs ($77.67{\pm}1.42kg$ average initial BW) were used in a 41-d growth assay to determine the effects of yucca extract supplementation on growth performance, nutrient digestibility and serum characteristics of finishing pigs. Dietary treatments included 1) Control (basal diet), 2) YE60 (basal diet+60 ppm yucca extract), 3) YE120 (basal diet+120 ppm yucca extract). Average daily gain was not improved by yucca extract supplementation during the whole experimental perid (d 0 to 41). Pigs fed control diet showed the best average daily gain. Pigs fed control and YE120 diets tended to increase average daily feed intake compared with pigs fed YE60 diet (quadratic effect, p<0.0001). Gain/feed with control treatment was significantly better than the YE groups (linear effect, p<0.071). However, there was no significant difference among levels of yucca extract (p>0.10). Apparent digestibility of dry matter in pigs fed yucca extract were greater than for pigs fed control diets (linear effect, p<0.017). Pigs fed YE120 tended to have higher digestibility of nitrogen than pigs fed the control diets (linear effect, p<0.019). There were no significant differences in Total-, HDL- and LDL-cholesterol concentrations of serum, and the blood urea nitrogen (BUN) concentrations in serum was not influenced by the yucca extract supplementation (p>0.10). For the Exp. 2, fifteen [(Duroc${\times}$Yorkshire)${\times}$Landrace] pigs ($25.00{\pm}0.50kg$ average initial BW) were used in a 30-d metabolism experiment to determine the effects of yucca extract supplementation on fecal ammonia gas production. Treatments were : 1) Control (basal diet); 2) YE (basal diet+150 ppm yucca extract); 3) BD (basal diet+100 ppm Bio-Dr; yucca extract+far infrared emitted materials). Fecal ammonia gas production differences between d 0 and d 30 were significantly reduced (p<0.05) by feeding BD compared to control and YE. Also, when pigs were fed the diet with YE tended to be decreased ammonia gas production compared to pigs fed the control diet without significant differences (p>0.05). There were no differences for DM and N digestibility among pigs fed the treatment diets. In conclusion, yucca and (or) far infrared radiological materials can be used to make environment-friendly diets for growing-finishing pigs without negative effects on growth performance and nutrient digestibility.

THE EFFECT OF SEVERAL ROOT-END FILLING MATERIALS ON MG63 OSTEOBLAST-LIKE CELLS (수종의 치근단역충전 재료가 MG63 osteoblast-like cells에 미치는 영향)

  • Lee, Jeong-Ho;Shon, Won-Jun;Lee, Woo-Cheol;Baek, Seung-Ho
    • Restorative Dentistry and Endodontics
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    • v.35 no.3
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    • pp.222-228
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    • 2010
  • The purpose of this study was to compare mineral trioxide aggregate (MTA; Dentsply, Tulsa Dental, Tulsa, OK, USA), which is widely used as root-end filling material, with DiaRoot BioAggregate (DB; Innovative BioCaramix Inc, Vancouver, BC, Canada), newly developed product, by using MG63 osteoblast-like cells. MTA, DB, and Intermediate Restorative Material (IRM; Dentsply Caulk, Milford, DE, USA) were used for root-end filling material while tissue culture plastic was used for control group. Each material was mixed and, the mixtures were left to set for 24 hours. MG63 cells were seeded to each group and then they were cultured for attachment for 4 hours. Following the attachment of cells to the root-end filling material, early cellular response was observed. After another 12 hours'culture, the level of attachment between cells and material was observed and in order to identify the effect of each material to bone formation, transforming growth factor beta1 ($TGF{\beta}1$) and osteocalin (OC) were estimated by using enzyme-linked immunosorbent assay (ELISA), and the amount of alkaline phosphatase (ALP) was also measured. The data were analyzed using one-way ANOVA. As a result, only at OC and the number of cells which were attached to materials, there was no statistical difference between MTA and DB. At other items, there was statistically significant difference in all groups. Although DB has not shown exactly the same cellular response like that of MTA, the number of attached cells shows that biocompatibility of the material and OC indicates bone formation rate. Therefore, if DB is used for root end filling material, it is expected to lead to similar results to MTA.

Inhibition of Cell Invasion by Indole-3-Carbinol in OVCAR-3 Human Ovarian Cancer Cells (Indole-3-carbinol에 의한 OVCAR-3 인체 난소암세포의 침윤 억제)

  • Choi, Yung-Hyun;Kim, Sung-Ok
    • Journal of Life Science
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    • v.21 no.7
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    • pp.923-931
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    • 2011
  • In the present study, we investigated the effect of indole-3-carbinol (I3C), a natural compound present in vegetables, on the cell migration and invasion of OVCAR-3 ovarian cancer cells. Our results indicated that I3C inhibited the proliferation of OVCAR-3 cells, a process which was associated with inhibition of cell motility as determined by wound healing experiments and cell invasion studies. I3C treatment increased the tightness of the tight junctions (TJs), which was demonstrated by an increase in transepithelial electrical resistance and a decrease in paracellular permeability. The RT-PCR and immunoblotting results indicated that I3C repressed the levels of claudin-3 as well as claudin-4, proteins that comprise a major part of TJs and play a key role in the control and selectivity of paracellular transport. Furthermore, the activities of matrix metalloproteinase (MMP)-2 and MMP-9 were also decreased by treatment with I3C, which was connected with the down-regulation of their mRNAs and protein expression. The results suggest that I3C may be expected to inhibit cancer cell metastasis and invasion by restoring TJs and decreasing MMP activity in ovarian cancer cell line OVCAR-3.

The Biological Degradation of High Concentration of Trichloroethylene (TCE) by Delftia acidovornas EK2 (Delftia acidovorans EK2에 의한 고농도 Trichloroethylene (TCE)의 생물학적 분해 특성)

  • Park, Woo-Jung;Lee, Sang-Seob
    • Korean Journal of Microbiology
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    • v.46 no.2
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    • pp.183-191
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    • 2010
  • In this study, we isolated 179 bacterial strains using benzene, phenol, ethylbenzene, aniline, cumene, toluene as growth substrate from TCE contaminated soils and wastewaters. All the 179 strains were screened for TCE (30 mg/L) removal (growth substrate 0.2 g/L, $30^{\circ}C$, pH 7, cell biomass 1.0 g/L (w/v)) under aerobic condition for 21 days. EK2 strain using aniline showed the highest removal efficiency (74.4%) for TCE degradation. This strain was identified as Delftia acidovorans as the results of API kit, 16S rDNA sequence and fatty acid assay. In the batch culture, D. acidovorans EK2 showed the bio-degradation for TCE in the various TCE concentration (10 mg/L to 200 mg/L). However, D. acidovorans EK2 did not show the bio-degradation in the TCE 250 mg/L. D. acidovorans EK2 also show the removal efficiency (99.9%) for 12 days in the low concentration (1.0 mg/L). Optimal conditions to degrade TCE 200 mg/L were cell biomass 1.0 g/L (w/v), aniline 0.5 g/L, pH 7 and $30^{\circ}C$. Removal efficiency and removal rate by D. acidovorans EK2 strain was 71.0% and 94.7 nmol/h for 21 days under optimal conditions. Conclusion, we expect that D. acidovorans EK2 may contribute on the biological treatment in the contaminated soil or industrio us wastewater.