• Journal of Food Hygiene and Safety
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• v.18 no.3
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• pp.118-124
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• 2003

For the rapid detection of various pathogenic microorganisms from food sample, various kinds of kits have been developed and commercially available in the markets. With the advantages of speed, accuracy and easiness, the market of these kits has gradually increased for the QC and QA field of food company as well as testing facilities or laboratories. In this study, the characteristics such as the detection limit and the sensitivity of immunochromatographic type of rapid detection kit (Donga Co, Korea, D-kit) for E. coli 0157:H7 developed by monoclonal antibody were examined and also the possibility of application of the kit to food samples was evaluated. The reference kits used for comparison study were Reveal E. coli 0157:H7 (Neogen Co., USA, R-kit) and VIP EHEC kit (Biocontrol Inc., USA, V-kit) occupying major market share. In the detection limit test with the E. coli 0157:H7 reference, both R-kit and D-kit showed a distinct positive reaction in $10^4$/ml and weak positive reaction in $10^3$/ml, whereas V-kit showed a same reaction in 105/ml. Also, it was identified that the culture treated with heat showed more sensitivity than no heat treated culture. The sensitivity test was conducted against 22 isolates of E. coli 0157:H7, 7 strains of non-O157:H7 verotoxin-producing E. coli, 40 strains of E. coli with different O and H antigen type, and 38 strains of non-E. coli Enterobacteriaceae, and all of the test strains except three were showed exactly three were showed exactly the same reaction against three kinds of the tested kits. All the three kinds of kits showed a positive reaction against E. coli O157:H19, E. coli O148:H18 and Salmonella galinarium. We suppose that there might be a similarity in serological property between these three strains and O157:H7. From the test results, it can be concluded that there is (was) no difference between the D-kit developed in this study and R-kit or V-kit based on the detection limit and sensitivity.

• Food Science of Animal Resources
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• v.36 no.2
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• pp.186-193
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• 2016

This study aimed to inhibit Escherichia coli (E. coli) O157:H7 artificially contaminated in fresh meat using bacteriophage. Among 14 bacteriophages, the highly lytic bacteriophage BPECO19 strain was selected to inhibit E. coli O157:H7 in artificially contaminated meat samples. Bacteriophage BPECO19 significantly reduced E. coli O157:H7 bacterial load in vitro in a multiplicity of infection (MOI)-dependent manner. E. coli O157:H7 was completely inhibited only in 10 min in vitro by the treatment of 10,000 MOI BPECO19. The treatment of BPECO19 at 100,000 MOI completely reduced 5 Log CFU/cm² E. coli O157:H7 bacterial load in beef and pork at 4 and 8h, respectively. In chicken meat, a 4.65 log reduction of E. coli O157:H7 was observed at 4 h by 100,000 MOI. The treatment of single bacteriophage BPECO19 was an effective method to control E. coli O157:H7 in meat samples.

• Microbiology and Biotechnology Letters
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• v.26 no.2
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• pp.89-95
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• 1998

Rhodopseudomonas sphaeroides K7 and E15-1 produced hydrogen from glucose rapidly for the first 24 hrs of culture under the anaerobic and photosynthetic conditions and then ceased the hydrogen production because of the accumulation of organic acids such as acetic acid and formic acid in the culture broth, decreasing the pH to 4.2-4.5. Only 43% and 73% of glucose in the culture were consumed even after 6 days of incubation by R. sphaeroides K7 and E15-1, respectively. The hydrogen production and glucose consumption, however, were substantially increased when the pH of the culture was adjusted to 6.8-7.0: Hydrogen production continues even after 10 days of culture and glucose was consumed completely after 2.5 and 4.5 days by R. sphaeroides K7 and E15-1, respectively, Furthermore, the bacteriochlorophyll contents in R. sphaeroides K7 and E15-1 were increased by 44 and 9 folds and the cell concentrations by 10 and 2.5 folds, respectively, after 7 days of culture. R. sphaeroides K7 and E15-1 also produced hydrogen from acetic, lactic, butyric and malic acids under the anaerobic and photosynthetic conditions even though the amounts of hydrogen produced were lower than that from glucose. The results of this experiment indicate that under the anaerobic and synthetic conditions R. sphaeroides K7 and E15-1 might use the NADH oxidation mediated by ferredoxin and hydrogenase to evolve hydrogen from glucose for the first 24 hrs and then the organic acids produced were used as electron donners for the production of hydrogen in the nitrogen-limited condition.

• Progress in Medical Physics
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• v.34 no.2
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• pp.15-22
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• 2023

This study compared the dose calculated using the electron Monte Carlo (eMC) dose calculation algorithm employing the old version (eMC V13.7) of the Varian Eclipse treatment-planning system (TPS) and its newer version (eMC V16.1). The eMC V16.1 was configured using the same beam data as the eMC V13.7. Beam data measured using the VitalBeam linear accelerator were implemented. A box-shaped water phantom (30×30×30 cm³) was generated in the TPS. Consequently, the TPS with eMC V13.7 and eMC V16.1 calculated the dose to the water phantom delivered by electron beams of various energies with a field size of 10×10 cm². The calculations were repeated while changing the dose-smoothing levels and normalization method. Subsequently, the percentage depth dose and lateral profile of the dose distributions acquired by eMC V13.7 and eMC V16.1 were analyzed. In addition, the dose-volume histogram (DVH) differences between the two versions for the heterogeneous phantom with bone and lung inserted were compared. The doses calculated using eMC V16.1 were similar to those calculated using eMC V13.7 for the homogenous phantoms. However, a DVH difference was observed in the heterogeneous phantom, particularly in the bone material. The dose distribution calculated using eMC V16.1 was comparable to that of eMC V13.7 in the case of homogenous phantoms. The version changes resulted in a different DVH for the heterogeneous phantoms. However, further investigations to assess the DVH differences in patients and experimental validations for eMC V16.1, particularly for heterogeneous geometry, are required.

• BMB Reports
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• v.49 no.8
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• pp.431-436
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• 2016

Human papillomavirus (HPV) is the major cause of cervical cancer, a deadly threat to millions of females. The early oncogene product (E7) of the high-risk HPV16 is the primary agent associated with HPV-related cervical cancers. In order to understand how E7 contributes to the transforming activity, we investigated the structural features of the flexible N-terminal region (46 residues) of E7 by carrying out N-15 heteronuclear NMR experiments and replica exchange molecular dynamics simulations. Several NMR parameters as well as simulation ensemble structures indicate that this intrinsically disordered region of E7 contains two transient (10-20% populated) helical pre-structured motifs that overlap with important target binding moieties such as an E2F-mimic motif and a pRb-binding LXCXE segment. Presence of such target-binding motifs in HPV16 E7 provides a reasonable explanation for its promiscuous target-binding behavior associated with its transforming activity.

• YAKHAK HOEJI
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• v.45 no.4
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• pp.339-346
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• 2001

A new oxygenated monoterpene (4) was isolated from the methanol extract of the aerial part of Erechtites hieracifolia together with six known components, a dimethylheptane (1), three ionone derivatives (2, 3 and 7) and two phenylpropanoids (5 and 6). Their structures were identified by means of physico-chemical and spectral data to be (2E, 5E)-6-hydroxy-2,6-dimethylhepta-2,4-dienal (1), 3(R)-hydroxy-5,6-epoxy-$\beta$-ionone (2), 3(R)-hydroxy-5,6-epoxy-7-ionol (3), (3E, 6E)-3,7-dimethylocta-3,5-dien-1,2,7-triol(4), 2-hydroxy-4-(2-propenyl)phenyl-$\beta$-D-glucopyranoside (5), 2-methoxy-4-(2-propenyl)phenyl -$\beta$-D-glucopyra-noside (6) and (6R, 9R)-3-oxo-$\beta$-ionol-$\alpha$-D -glucopyranoside (7).

• Molecules and Cells
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• v.39 no.2
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• pp.129-135
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• 2016

Eukaryotic translation initiation factor 2 alpha ($eIF2{\alpha}$), which is a component of the eukaryotic translation initiation complex, functions in cell death and survival under various stress conditions. In this study, we investigated the roles of $eIF2{\alpha}$ phosphorylation in cell death using the breast cancer cell lines MCF-7 and MCF-7/ADR. MCF-7/ADR cells are MCF-7-driven cells that have acquired resistance to doxorubicin (ADR). Treatment of doxorubicin reduced the viability and induced apoptosis in both cell lines, although susceptibility to the drug was very different. Treatment with doxorubicin induced phosphorylation of $eIF2{\alpha}$ in MCF-7 cells but not in MCF-7/ADR cells. Basal expression levels of Growth Arrest and DNA Damage 34 (GADD34), a regulator of $eIF2{\alpha}$, were higher in MCF-7/ADR cells compared to MCF-7 cells. Indeed, treatment with salubrinal, an inhibitor of GADD34, resulted in the upregulation of $eIF2{\alpha}$ phosphorylation and enhanced doxorubicin-mediated apoptosis in MCF-7/ADR cells. However, MCF-7 cells did not show such synergic effects. These results suggest that dephosphorylation of $eIF2{\alpha}$ by GADD34 plays an important role in doxorubicin resistance in MCF-7/ADR cells.

• BMB Reports
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• v.34 no.1
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• pp.80-84
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• 2001

The human papillomavirus E7 protein can form a specific complex with a retinoblastoma tumor suppressor gene product (p105-Rb) that results in the release of the E2F transcription factor, which is critical for the growth-deregulation and transforming properties of the viral E7 oncoprotein. In an attempt to apply interaction between the E7 oncoprotein and a target cellular protein Rb for an in vitro screening system for drugs against human papillomavirus infection, we primarily investigated the E7Rb binding through a pull down assay and enzyme-linked immunosorbent assay. The pull down assay showed that both glutathione S-transferase-tagged E7 and His-tagged E7 immobilized on resins specifically produced complexes with bacterially expressed Rb in a dose-dependent manner, as determined by immunoblot analyses. This result coincided with that of an enzyme-linked immunosorbent assay, which is a useful system for the mass screening of potential drugs. Taken together, this screening system (based on the interaction between E7 and Rb) can be a promising system in the development of drugs against cervical cancers caused by human papillomavirus infection.

• Asian-Australasian Journal of Animal Sciences
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• v.19 no.11
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• pp.1665-1670
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• 2006

The objective of this research was to provide the characterization and method for producing anti-E. coli O157:H7 antibodies in egg-laying hens and to determine if the antibody can restrain the proliferation of E. coli O157:H7 in-vitro. Selected antigenic fractions (whole cell, outer membrane protein and lipopolysaccharide (LPS)) from E. coli O157:H7 were injected to hens in order to produce anti-E. coli O157:H7 antibodies. The immune response and the egg yolk antibodies of laying hens against the whole cell, outer membrane protein and LPS antigens were monitored by ELISA. The level of antibodies against whole cell antigen monitored through ELISA sharply increased after the initial immunization, and it was found to be maximum on day 49 however, the level was maintained up to day 70. Antibodies (5 mg/ml) directed against the whole cell inhibited E. coli proliferation 10-13 times more than outer membrane protein or LPS. The antibody response against the whole cell antigens appeared to have higher activity in restraining the proliferation of E. coli O157:H7 than antibody against outer membrane protein or LPS. Results reflected that increasing the IgY's in the egg yolk could prevent greater economic losses due to human and animal health from pathogenic bacteria i.e. E. coli O157:H7.

• Journal of Aquaculture
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• v.11 no.2
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• pp.241-248
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• 1998

Effects of A23187 on estradiol$-17^{\beta}$-induced vitellogenin (VTG) induction were electrophore-tically examined in primary hepatocyte cultures in rainbow trout. hepatocytes were predultured for 2 days and then estradiol-$17^{\beta}$(E2, $2{\times}10^{-6}$M) and calcium ionophore (A23187, $10^{-7)$~$10^{-5}$ M) were added to the incubation medium. The hepatocytes were cultured for 7 more days. In addition, effects of A23187 on $E_2$-primed VTG production were investigated for 7 days. The addition of A23187 ($10^{-7)$~$10^{-5}$M) to the incubation medium specifically reduced VTG production by hepatocytes in a concentration-dependent way. The addition of A23187 significantly reduced the rate of $E_2$-primed VTG production to 18% of the control (E2 only) on Day 7. However, $E_2$-primed VTG production was reduced to 47% of the control by withdrawal of $E_2$ from the incubation medium. Therefore, these results suggest that intracellualr sequestered calcium could regulate VTG synthesis at the translational and/or post-translational stage.