• Korean Journal of Microbiology
• /
• v.46 no.1
• /
• pp.21-26
• /
• 2010

As the causative agent of Anthrax, Bacillus anthracis causes an acute fatal disease in herbivores such as cattle, sheep, and horses as well as humans. The therapeutics and prevention of anthrax currently available are based on antibiotics and the live attenuated vaccine strains, which may be problematic due to the emergency of antibiotic resistant strains or residual virulence in those vaccine strains. Therefore, it has been required to develop novel therapeutics and vaccines which are safer and applicable to humans. Recently, the development of the multivalent vaccine targeting both spores and vegetative cells of B. anthracis along with anthrax toxin has been reported. In our attempts to screen potential candidates for those multivalent vaccines, the whole genomic expression library of B. anthracis was constructed in this study. To the end, the partial digests of the genomic DNA from B. anthracis (ATCC 14578) with Sau3AI were ligated with the inducible pET30abc expression vectors, resulting in approximately $1{\times}10^5$ clones in E. coli BL21(DE3). The redundancy test by DNA nucleotide sequencing was performed for the randomly selected 111 clones and found 56 (50.5%) B. anthracis genes, 17 (15.3%) vector sequences, and 38 (34.2%) unknown genes with no sequence homology by BLAST. An inducible expression of the recombinant proteins was confirmed by Western blot. Interestingly, some clones could react with the antiserum against B. anthracis. These results imply that the whole genomic library constructed in this study can be applied for analyzing the immunomes of B. anthracis.

• Korean Journal of Microbiology
• /
• v.49 no.1
• /
• pp.64-70
• /
• 2013

The greenhouse whitefly, Trialeurodes vaporariorum, is an economically important pest for greenhouse crops because they cause direct damage by feeding on plant nutrients and indirect damage as transmits many virus vectors. It has recently become a serious problem because of the continuous use of insecticide resulting in resistance among greenhouse whitefly population. To overcome these problems, in this study, the biological characteristics and virulence of an entomopathogenic fungus isolated from the cadaver of nymph greenhouse whitefly were investigated. Isolated fungus was identified as Isaria fumosorosea by morphological examinations and genetic identification using sequences of the ITS, ${\beta}$-tubulin, and EF1-${\alpha}$ regions. This fungus was named as I. fumosorosea SDTv and tested for the virulence against nymphs T. vaporariorum and the cold activity, the thermotolerance and the stability of UV-B irradiation on conidia. Mortality rate of greenhouse whitefly showed from 84 to 100% and the virulence increased with increasing conidial concentrations, $1{\times}10^5$ to $10^8$ conidia/ml. Conidia were stable at $35^{\circ}C$, 0.1 $J/cm^2$ of UV irradiation and germinated after 8 days at $4^{\circ}C$. Additionally, the activities of chitinases and proteases produced by I. fumosorosea SDTv were varied according to the medium. In conclusion, I. fumosorosea SDTv which showed high mortality rate against greenhouse whitefly will be used effectively in the integrated pest management programs against the greenhouse whitefly.

• Journal of the Korean Society of Food Science and Nutrition
• /
• v.40 no.6
• /
• pp.767-774
• /
• 2011

Defatted green tea seed was extracted with 100% ethanol for 4 hr and then fractionated with petroleum ether, ethyl acetate and butanol. The ethanol and butanol extracts showed greater increases in antiproliferation potential against liver cancer cells than petroleum ether, ethyl acetate, $H_2O$, and hot water extracts did. Thus, this study was carried out to investigate the anti-proliferative actions of defatted green tea seed ethanol extract (DGTSE) in HepG2 cancer cells. The DGTSE contained catechins including EGC ($1039.1{\pm}15.2\;g/g$), tannic acid ($683.5{\pm}17.61\;{\mu}g/g$), EC ($62.4{\pm}5.00\;{\mu}g/g$), ECG ($24.4{\pm}7.81\;{\mu}g/g$), EGCG ($20.9{\pm}0.96\;{\mu}g/g$) and gallic acid ($2.4{\pm}0.68\;{\mu}g/g$), but caffeic acid was not detected when analyzed by HPLC. The anti-proliferation effect of DGTSE toward HepG2 cells was 83.13% when treated at $10\;{\mu}g$/mL, of DGTSE, offering an $IC_{50}$ of $6.58\;{\mu}g$/mL. DGTSE decreased CYP1A1 and CYP1A2 protein expressions in a dose-dependent manner. Quinone reductase and antioxidant response element (ARE)-luciferase activities were increased about 2.6 and 1.94-fold at a concentration of $20\;{\mu}g$/mL compared to a control group, respectively. Enhancement of phase II enzyme activity by DGTSE was shown to be mediated via interaction with ARE sequences in genes encoding the phase enzymes. DGTSE significantly (p<0.05) suppressed prostaglandin $E_2$ level, tumor necrosis factor-${\alpha}$ (TNF-${\alpha}$) protein expressions, and NF${\kappa}$B translocation, but did not affected nitric oxide production. From the above results, it is concluded that DGTSE may ameliorate tumor and inflammatory reactions through the elevation of phase II enzyme activities and suppression of NF${\kappa}$B translocation and TNF-${\alpha}$ protein expressions, which support the cancer cell anti-proliferative effects of DGTSE in HepG2 cells.

• Korean journal of applied entomology
• /
• v.50 no.2
• /
• pp.157-165
• /
• 2011

Enterobacteria were isolated in the gut of the predacious multicolored Asian ladybird beetle, Harmonia axyridis, and their effects to the development of H. axyridis were examined. Populations of H. axyridis in this experiment were collected from Kimjae at Cheonbuk province (JK population), Geumsan at Chungnam province (CK population) and laboratory population at Laboratory of Insect Physiology in Chungnam National University, Daejeon. Thirty-four enterobacteria isolates were purified and isolated from the digestive tract of H. axyridis, and a total of 4 strains were classified into group by analysis of 16S rRNA gene sequences. About 70% of total isolates were phylogenetic groups of Bacillus genus and Staphylococcus genus, and they were commonly separated from the digestive tract of H. axyridis. After investigating their susceptibility against antibiotics with 18 representative enterobacteria isolates, ofloxacin and penicillin were selected for examination in this study of their ability to inhibit the growth of all of isolates. In order to remove the enterobacteria from the aphids, ofloxacin and penicillin were given to the green peach aphid, Myzus persicae, and the turnip aphid, Lipaphis erysimi. These aphids were provided to H. axyridis as prey. The weight of pupa, developmental periods of each larval instar, the number of eggs and their hatching ratio of H. axyridis with treatment aphids were lower compared with non-treatment aphids. Staphylococcus saprophyticus is a representative enterobacteria and commonly isolated from the digestive tract of H. axyridis. In the absence of S. saprophyticus, the developmental periods of each larval instar increased; however, the weights of pupa, the number of eggs, and their hatching ratio decreased.

• Journal of fish pathology
• /
• v.6 no.2
• /
• pp.93-101
• /
• 1993

The RNAI mutation of Saccharomyces cerevisia is a recessive and temperature sensitive lethal mutation which interferes with the production of mRNA, rRNA, and tRNA. However, the precise role of RNAI gene have not been revealed until yet. We have cloned rna1-1 mutant gene from rna1-1 mutant yeast strain(R49 ; trpl, ura3-52, rna1-1). The 3.4kb BglII fragment of wild type RNAI clone(81-2-6) contains whole RNAI gene. The genomic southern blotting with BglII digested R49 genomic DNA as a probe shows the unique and identical band with wild type 3.4kb BglII fragment. Therefore, We prepared partial BglII genomic library(3~4kb BglII fragments) into BamH I site of pUC19. The rna 1-1 mutant clone was screened with Digoxigenin(DIG)-lableled probe by high density colony hybridization. The 5'-flanking region of rna1-1 gene was sequenced by dideoxy chain termination method. The 5'-flanking sequence of RNAI gene contains three TATA-like sequence ; TAATA, TATA and TTTTAA at position of -67, -45, and -36 from first ATG codon respectively. The 5'-flanking region of wild type RNA I gene from ATG codon to -103nt was deleted with Bal31 exonuclease digestion, generating $pUC{\Delta}$/RNA I. After constructing $pYEP{\Delta}RNA$ I (consists of -103nt deleting RNA I gene, URA3 gene, $2{\mu}m$ rep. origin), pYEPrna1-1(consists of Xba I fragment of pUCrna1-1. URA3 gene, $2{\mu}m$ rep. origin), and pYEPRNAI. each plasmid was transformed into host strain(trpl, ura3-52, rna1-1) by electroporation, respectively. Yeast transformant carrying $pYEP{\Delta}RNA$ I did not complement the thermal sensitivity of rna1-1 gene. It means that TATA-like sequences in 5'-flanking region is not TATA sequence for transcribing RNAI gene and there may be other essential sequence in upstream region for the transcription of RNAI gene.

• Journal of Sericultural and Entomological Science
• /
• v.36 no.2
• /
• pp.138-146
• /
• 1994

The structural characteristics of Antheraea yamamai and Antheraea pernyi silk were investigated by using x-ray diffraction method, IR spectroscopy and polarizing microscopy. The amino acid composition, fiber density, thermal decomposition temperature and glass transition temperature were also measured for relating these physical properties to the structure in comparison with those of Bombyx mori silk fiber. There was no significant structural difference between A. yamamai and A. pernyi silk fiber on an examination of x-ray diffraction curve and IR spectrum. Both of these wild silk fibers showed double diffraction peaks at the Bragg angle 2Θ16.7˚ and 20.5˚by x-ray diffraction analysis as well as IR absorption peaks for the bending vibration of specific groups related to ala-ala amino acid sequence. On the other hand, the x-ray diffraction curve and IR spectrum of Bombyx mori silk fiber are different from those of wild silk fibers, indicating different crystal structure as well as amino acid sequences. It showed under the polarizing microscope examination that the birefringence and optical orientation factor of wild silk fibers are much lower than those of B. mori silk. Also, the surface of degummed wild silk fibers was characterized by the longitudinal stripes of microfibrils in the direction of fiber axies. The amino acid composition, which is strongly related to the fine structure and properties, was not significantly different between these two wild silk fibers. However, the alanine content was somewhat less and polar amino acid content more for A. yamamai. As a result of fiber density measurement, the specific gravities of B. mori, A. pernyi and A. yamamai were 1.355~1.356, 1.308~1.311, 1.265~1.301g/㎤ in the order, respectively. The calculated crystallinity(%) was 64% for B. mori and 51~52% for wild silk fibers, which showed same trend by IR method in spite of somewhat higher value. The thermal decomposition behaviour was examined by DSC and TGA, showing that the degradation temperature was in the order of B mori, A. prernyi and A. yamamai at around 350$^{\circ}C$. It was also observed by TGA that the decomposition seems to proceed step by step according to their specific regions in the fiber structure, resulting the difference in their thermal stabilities. The glass transition temperature was turned out to be 220$^{\circ}C$ for B. mori, 240$^{\circ}C$ A. yamamai and 255$^{\circ}C$ A. pernyi by the dynamic mechanical analysis. It is expected that the chemical properties are affected by the dynamic mechanical behavior in accordance with their structural characters.

• Clinical and Experimental Pediatrics
• /
• v.49 no.12
• /
• pp.1340-1347
• /
• 2006

Purpose : The aim of the present study was to investigate the role of polymorphic cytosine adenine (CA) repeat of the IGF-I gene in the age-related alterations of serum IGF-I levels in healthy children. Methods : Two hundred and forty three normal healthy children (136 boys; 107 girls) aged between 7 and 15 years were enrolled in the present study. The primers were designed to cover the promoter regions containing the polymorphic CA repeat. Data were analyzed using GeneMapper software, version 3.7. All analyses were performed using MEDCALC software packages. Results: Deletion of 2 bp (G, A) following 3' of CA repeat were observed in all Korean children. The CA repeat sequences ranged from 17 to 23, and 19 CA repeat were the most common with an alleles frequency of 39.3 percent. Considering genotypes, 63.8 percent of subjects were homozygote or heterozygote for 19 CA repeat (192 bp allele), suggesting that this is wild type allele from which all other alleles originated in Korean children. Homozygote for 19 CA repeat were 14.7 percent, heterozygote for 19 CA repeat was 49.1 percent and 19 CA noncarriers totalled 36.2 percent. In 19 CA repeat noncarriers, the mean height, weight and serum IGF-I level were lower compared with those of 19 CA homozygous carriers, but statistically not significant. Correlations between serum IGF-I level and age according to the IGF-I genotypes revealed statistically significant relationships in the all groups, in the 19 CA repeat carrier group and, even in the noncarrier group. Conclusions : There were no significant differences of the mean height, weight and serum IGF-I levels among three different genotype groups. Also, there were no significantly different correlations between 19 CA repeat polymorphisms and serum IGF-I levels, according to genotype. Our results suggest that the IGF-I 19 CA repeat gene polymorphism is not associated with circulating IGF-I levels in healthy children.

• Progress in Medical Physics
• /
• v.23 no.3
• /
• pp.177-187
• /
• 2012

Magnetic resonance angiography (MRA) techniques are widely used in diagnosis of vascular disorders such as hemadostenosis and aneurism. Especially, phase contrast (PC) MRA technique, which is a typical non contrast-enhanced MRA technique, provides not only the anatomy of blood vessels but also flow velocity. In this study, we developed the 2- and 3-dimensional PC MRA pulse sequences for a low magnetic field MRI system. Vessel images were acquired using 2D and 3D PC MRA and the velocities of the blood flow were measured in the superior sagittal sinus, straight sinus and the confluence of the two. The 2D PC MRA provided the good quality of vascular images for large vessels but the poor quality for small ones. Although 3D PC MRA gave more improved visualization of small vessels than 2D PC MRA, the image quality was not enough to be used for diagnosis of the small vessels due to the low SNR and field homogeneity of the low field MRI system. The measured blood velocities were $25.46{\pm}0.73cm/sec$, $24.02{\pm}0.34cm/sec$ and $26.15{\pm}1.50cm/sec$ in the superior sagittal sinus, straight sinus and the confluence of the two, respectively, which showed good agreement with the previous experimental values. Thus, the developed PC MRA technique for low field MRI system is expected to provide the useful velocity information to diagnose the large brain vessels.

• Investigative Magnetic Resonance Imaging
• /
• v.1 no.1
• /
• pp.135-141
• /
• 1997

Purpose: To assess the usefulness of breath-hold fast MR imaging of liver with fat suppression (FS) by application of chemical saturation technique in the diagnosis of regional fatty changes suspected in sonography. Materials and Methods: Thirteen patients who had focal lesions with diffuse, homogeneous signal changes after FS through chemical saturation technique without additional changes of imaging parameter during MR imaging of liver were selected. T1-weighted fast low-angle shot and T2-weighted turbo spin-echo sequences were obtained with or without FS during each single breath-holding session. Subjective changes of signal intensity between the pre-FS and the FS images were compared with the sonographic findings in each lesion. Results: Seven lesions of decreased signal intensity after FS on T1 or T2-weighted images, including three lesions only at FS T1 images, were regarded as focal fat infiltration. All seven lesions had compatible sonographic findings as homogenously echogenic areas. Another six lesions of subjectively increased signal intensity including two lesions only at FS T2 images were regarded as focal fat sparing. All six lesions had sonographic findings as homogenous echo poor areas suggesting focal fat sparing. In cases regarded as fat infiltration, score changes were more prominent at FS T1 images than FS T2 images(p=0.0002). In cases regarded as fat sparing, score changes were more prominent at FS T2 images than FS T1 images(p=0.042). Conclusion: Breath-hold fast T1 and T2-weighted MR imaging with and without chemical saturation pre-pulse may be sufficient for characterization of regional fatty changes in the differential diagnosis of focal hepatic lesion found at sonography.

• Investigative Magnetic Resonance Imaging
• /
• v.10 no.2
• /
• pp.98-107
• /
• 2006

Magnetization Transfer (MT) imaging generates contrast dependent on the phenomenon of magnetization exchange between free water proton and restricted proton in macromolecules. In biological materials in knee, MT or cross-relaxation is commonly modeled using two spin pools identified by their different T2 relaxation times. Two models for cross-relaxation emphasize the role of proton chemical exchange between protons of water and exchangeable protons on macromolecules, as well as through dipole-dipole interaction between the water and macromolecule protons. The most essential tool in medical image manipulation is the ability to adjust the contrast and intensity. Thus, it is desirable to adjust the contrast and intensity of an image interactively in the real time. The proton density (PD) and T2-weighted SE MR images allow the depiction of knee structures and can demonstrate defects and gross morphologic changes. The PD- and T2-weighted images also show the cartilage internal pathology due to the more intermediate signal of the knee joint in these sequences. Suppression of fat extends the dynamic range of tissue contrast, removes chemical shift artifacts, and decreases motion-related ghost artifacts. Like fat saturation, phase sensitive methods are also based on the difference in precession frequencies of water and fat. In this study, phase sensitive methods look at the phase difference that is accumulated in time as a result of Larmor frequency differences rather than using this difference directly. Although how MT work was given with clinical evidence that leads to quantitative model for MT in tissues, the mathematical formalism used to describe the MT effect applies to explaining to evaluate knee disorder, such as anterior cruciate ligament (ACL) tear and meniscal tear. Calculation of the effect of the effect of the MT saturation is given in the magnetization transfer ratio (MTR) which is a quantitative measure of the relative decrease in signal intensity due to the MT pulse.