• Journal of Animal Science and Technology
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• v.50 no.4
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• pp.445-456
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• 2008

Telomeres consist of TTAGGG tandem repeated DNA sequences with specific proteins and locate at chromosome ends. Telomeres are essential for chromosome stability and are related with cell senescence, apoptosis and cancer. Telomerase is a ribonucleoprotein which has a template for the synthesis of telomeric DNA. This study was carried out to analyze the amount of telomeric DNA and telomerase activity in cattle cells. Analysis of the quantity of telomere in lymphocytes was done at different ages, sex and among Korean cattle and Holstein breeds. The telomerase activity was also analyzed in liver, brain, heart, kidney, and testis tissues of fetal calf and of 18 month old cattle. The amount of telomeres in lymphocytes and other tissue cells was analyzed by Quantitative-Fluorescence in situ Hybridization (Q-FISH) technique using a telomeric DNA probe. Telomerase activity was analyzed by Telomeric Repeat Amplification Protocol assay (TRAP). The amount of telomeric DNA on the lymphocytes during the whole life span was decreased along with age. Quantity of telomeres in Korean cattle was significantly higher than that in Holstein breed. The amount of telomeric DNA in males was significantly higher than that in females. Telomerase activity was up-regulated in most bovine tissues during fetal stage, but was down-regulated in most tissues at mature 18 month age except the testis cells. This study indicates that the amount of telomeres and telomerase activity of cells can be used as an age marker or/and a physiological marker of cattle.

• Journal of Radiation Protection and Research
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• v.29 no.4
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• pp.243-249
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• 2004

The cytokinesis-block micronucleus (CBMN) assay in combination with FISH technique using chromosome-specific centromeric probes for chromosome 1 and 4 was performed in mitogen stimulated human lymphocytes which were exposed to x-radiation to identify different sensitivity of chromosomes to the induction of micronuclei(MN) and aneuploidy by radiation. The frequencies of micronucleated cytokinesis-blocked(MNCB) cells and MN in binucleated lymphocytes(BN) increased with the increase in radiation dose. A significant induction of aneuploidy of chromosome 1 and 4 were found. The frequency of aneuploidy of chromosome 1 and 4 in the control were 9 per 2,000 BN cells and this increased to 47 and 71 following irradiation at a dose of 1 and 2 Gy, respectively. The induction of aneuploidy of chromosome 1 was higher than that of chromosome 4. The frequency of aneuploid BN cells with MN exhibiting positive centromere signal for either chromosome 1 and/or 4 increased in a dose dependent manner, and that for chromosome 1 is higher than that for chromosome 4. Among the total induced MN in irradiated lymphocytes, smaller proportion of MN exhibit centromeric signal of chromosome indicating that radiation-induced MN are mainly originated from chromosomal breakage rather than chromosomal non-disjunction. These results suggest that x-radiation can induce aneuploidy and supports the finding that chromosome vary in their sensitivity to aneuploidy induction by x-irradiation.

• The Korean Journal of Malacology
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• v.29 no.1
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• pp.15-21
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• 2013

Nitric oxide (NO) is an important intra-intercellular signaling molecule that regulates many physiological processes and participates in the development some pathological conditions in animals. In this study, we compared different methods for determining NO concentration in the hemocytes of Manila clam Ruditapes philippinarum. For measuring the intracellular NO levels, we used the specific fluorescent probe 4,5-diaminofluorescein diacetate (DAF-2 DA), and the quantification methods that were compared were based on image analysis, spectrophotometry, and flow cytometry. NO concentration could be determined using all the 3 methods, and the concentration varied significantly depending upon the presence of NO regulators in the hemocytes; NO concentration increased in the presence of L-arginine, while it decreased in the presence of N-nitro-L-arginine methyl ester. In particular, it is found that estimation of NO using a flowcytometry is more economical, reliable and accurate compared to image analysis and spectrophotometry. Accordingly we believe that determining NO concentration by using flowcytometry will be useful in evaluating physiological and pathological conditions in marine bivalves.

• Animal cells and systems
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• v.1 no.1
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• pp.157-164
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• 1997

Ly-6E.1 antigen was proposed as a regulatory molecule of T lymphocyte activation, a hematopoietic stem cell marker, a memory cell marker, and an adhesion molecule. Though there were several reports suggesting the presence of Ly-6 ligand, the characterization of the ligand was not yet performed, As an attempt to screen the expression of Ly-6E.1 ligand, we prepared a probe for detecting Ly-6E.1 ligand by producing a fusion protein between Ly-6E.1 and $hlgC_{r1}$, A mammalian cell expression vector with Ly-6E.$1/hlgC_{r1}$ chimeric cDNA was transfected in SP2/0-Ag14 myeloma cells, and stable transfectants were selected. The fusion protein was produced as a dimer and maintained the epitopes for monoclonal antibodies specific for Ly-6E.1 and for anti-human lgG antibody. The purified fusion protein through Gammabind G column was used for FACS analyses for the expression of Ly-6E.1 ligand. The fusion protein interacted with several cell lines originating from B cells, T cells, or monocytes. The fusion Protein also strongly stained bone marrow, lymph node, and spleen cells, but thymic cells weakly, if any. The staining was more obvious in C57BL/6 $(Ly-6^b)$ than Balb/c $(Ly-6^a)$ mice. These results suggest that the interaction of Ly-6E.1 with Ly-6E.1 ligand may function both in the stem cell environment and in the activation of mature lymphocytes. The fusion protein may be a valuable tool in characterization of biochemical properties of the Ly-6E.1 ligand and, further, in isolating its cDNA.

• Biomedical Science Letters
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• v.5 no.2
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• pp.135-145
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• 1999

A total of 45 Staphylococcus aureus strains from clinical samples were tested for the biochemical test and antibiotic susceptibility test. Forty-five S. aureus strains were subjected to the molecular epidemiological study by susceptiblity test, antibiogram, bacteriophage typing, polymerase chain reaction and mec-associated hypervariable region gene in order to detect of mecA gene which was one of the structural gene related to antibiotic resistant expression factors. Three of 15 mecA-negative S. aureus isolates were classified as oxacillin resistant despite borderline minimal inhibitory concentration values. Methicillin susceptiblities were completely consistent with PCR results for these strains. On the other hand, 4 of 30 mecA-positive isolates yielded results in the oxacillin and methicillin susceptibility tests which were discrepant from those of PCR analysis. Except for SA6, the methicillin resistant S. aureus strains tested were highly resistant to penicillin, oxacillin, gentamicin, and chloramphenicol. In the phage typing, 27 strains were typable. The Iytic group III was as many as 12 strains, and 7 of 12 were 75/83A/84 type. In the PCR of specific mecA gene probe with chromosomal DNA of 30 methicillin resistant S. aureus, the amplified DNA band of 533 bp was confirmed in 30 strains and not in methicillin sensitive S. aureus. The single amplified band of hypervariable region related to mec was investigated in all of 30 methicillin resistant S. aureus, but in methicillin sensitive S. aureus it was amplified. The size of PCR products was between 200 bp and 600 Up. Four units was directly repeated.

• Bulletin of the Korean Chemical Society
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• v.34 no.8
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• pp.2419-2424
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• 2013

Guanosine-5'-diphosphate 3'-diphosphate (ppGpp) serves as alarmone in bacterial stringent responses. In this study, an affinity column was constructed by immobilizing ppGpp to NHS-Sepharose for isolating ppGpp-binding proteins. A novel ppGpp-binding protein, YjgA, was isolated and characterized by MALDI-TOF MS (matrix-assisted laser desorption ionization-time-of-flight mass spectrometry) coupled with two-dimensional gel electrophoresis. YjgA and truncated forms of YjgA were cloned and over-expressed in BL21 (DE3). The binding affinity of YjgA to ppGpp was determined by equilibrium dialysis. The interaction of YjgA with ppGpp was very specific, considering that the dissociation constant of YjgA with ppGpp was measured as $5.2{\pm}2.0{\mu}M$, while the affinities to GTP and GDP were about 60 and 30 times weaker than ppGpp. Expression of yjgA gene in Escherichia coli K-12 MG1655 was examined by reverse transcription polymerase chain reaction (RT-PCR). RT-PCR results revealed that yjgA was expressed from early to late stationary phase. The yjgA deletion mutant exhibited decreased cell number at stationary phase compared to parent strain and the over-expression of YjgA increased the cell number. These results suggested that YjgA might stimulate cell division under stationary phase. In most prokaryotic genome, about half of the protein candidates are hypothetical, that are expected to be expressed but there is no experimental report on their functions. The approach utilized in this study may serve as an effective mean to probe the functions of hypothetical proteins.

• 한국균학회소식:학술대회논문집
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• 2006.10a
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• pp.32-44
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• 2006

To investigate non-aflatoxin-production of A. oryzae at the molecular level, an aflatoxin biosynthesis gene homolog cluster of RIB 40 was analyzed. Although most genes in the corresponding cluster exhibited from 97 to 99 % similarity to those of Aspergillus flavus, three genes shared 93 % similarity or less. In addition, although slight expression of aflR, positive transcriptional regulator gene, was detected in some A. oryzae strains having seven aflatoxin biosynthesis homologous genes, other genes related to aflatoxin production were not detected. RIB strains were mainly divided into group 1, having seven aflatoxin biosynthesis homologous genes (aflT, nor-i, aflR, norA, avnA, verB, and vbs), and group 2, having three homologous (avnA, verB, and vbs). Partial aflatoxin homologous gene cluster of RIB62 from group 2 was sequenced and compared with that of RIB40 from group 1. RIB62 showed a large deletion upstream of ver-1 with more than half of the aflatoxin homologous gene cluster missing including aflR, a positive transcriptional regulatory gene. Adjacent to the deletion of the aflatoxin homologous gene cluster, RIB62 has a unique sequence of about 8kb and a telomere. Southern analysis of A. oryzae RIB strains with four kinds of probe derived from the unique sequence of RIB62 showed that all group 2 strains have identical hybridizing signals. Polymerase chain reaction with specific primer set designed to amplify the junction between ver-1 and the unique sequence of RIB62 resulted in the same size of DNA fragment only from group 2 strains. Based on these results, we developed a useful genetic tool that distinguishes A. oryzae group 2 strains from the other groups' strains and propose that it might have differentiated from the ancestral strains due to chromosomal breakage.

• Korean Chemical Engineering Research
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• v.48 no.2
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• pp.172-177
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• 2010

This study reports the high-temperature oxidation kinetics, ASR(area specific resistance), and interfacial microstructure of metallic interconnects coated with conductive oxides in oxidation atmosphere at $800^{\circ}C$, The conductive material LSC($La_{0.8}Sr_{0.2}CoO_3$, prepared by Solid State Reaction) was coated on the Crofer22APU. The contact behavior of coating layer/metal substrate was increased by sandblast. The electrical conductivity of the LSC coated Crpfer22APU was measured by a DC two probe four wire method for 4000hr, in air at $800^{\circ}C$. Microstructure and composition of the coated layer interface were investigated by SEM/EDS. These results show that a coated LSC layer prevents the formation and growth of oxide scale such as $Cr_2O_3$ and enhances the long-term stability and electrical performance of metallic interconnects for SOFCs.

• Journal of Biomedical Engineering Research
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• v.25 no.6
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• pp.611-615
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• 2004

A neural prostheses can be designed to permit stimulation of specific sites in the nervous system to restore their functions, lost due to disease or trauma. This study focuses on the feasibility of optoelecronic stimulation into nervous system. Optoelectronic stimulation supplies, power and signal into the implanted optical detector inside the body by optics. It can be effective strategy especially on the retinal prosthesis, because it enables the non-invasive connection between the external source and internal detector through natural optical window 'eye'. Therefore, we designed an effective neural stimulating setup by optically based stimulation. Stimulating on the sciatic nerve of a rat with proper depth probe through optical stimulation needs higher ratio of current spreading through the neural surface, because of high impedance of neural interface. To increase the insertion current spreading into the neuron, we used a parallel low resistance compared to load resistance organic interface and calculated the optimized outer parallel resistance for maximum insertion current with the assumption of limited current by photodiode. Optimized outer parallel resistance was at a range of 500Ω-700Ω and a current was at a level between 580uA and 650uA. Stimulating current efficiency from initial photodiode induced current was between 47.5 and 59.7%. Various amplitude and frequency of the optical stimulation on the sciatic nerve showed the reliable visual tremble, and the action potential was also recorded near the stimulating area. These result demonstrate that optoelectronic stimulation with no bias can be applied to the retinal prosthesis and other neuroprosthetic area.

• Journal of Korean Society of Transportation
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• v.27 no.5
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• pp.39-49
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• 2009

This research analyzes current pedestrian's safety zone choice standard problem and described about correct standard re-thesis at real. About problem of pedestrian traffic accidents to specific item statistical data to basis ramification of pedestrian traffic accidents, occurrence type of accident, action type etc. synthetically analyze and mark pedestrian's safety zone by countermeasure for decrease of pedestrian traffic accidents and utilize operating domestic outer garment reward and drew domestic Zone30 zone choice standard. Also, because analyzing effect that traffic discharge and speed through on-the-spot probe get in pedestrian thinking, presented quantitative standard, and analyze accident special quality of back pedestrian traffic accidents occurrence number of item and so on do accident type beside quantitative standard, road function, accident latitude and present standard. Specially, take advantage of statistical data of traffic accidents and put emphasis in pedestrian safety. Also, because establishment standard about safety facility establishment of Zone30 zone and systematic thesis of operation way do not consist, standard guide of consistency it is no and does equipment that is established in Zone30 zone because confusion happens by each local unit presented establishment and operation way, and present Zone30 zone.