• Journal of Microbiology and Biotechnology
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• v.14 no.6
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• pp.1280-1285
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• 2004

Retron is a prokaryotic genetic element, producing a short single-stranded DNA covalently linked to RNA (msDNA-RNA) by a reverse transcriptase (RT). In retron EC83, msDNA is further processed at between the 4th and the $5^{th}$ nucleotides, leaving a 79 nucleotide-long single-stranded DNA as a final product. To investigate this site-specific cleavage in msDNA synthesis, we purified the RT protein of retron EC83. Initially, RT ORF was cloned under the tac promoter, but the expression was very poor largely because of poor translation. In order to facilitate translation, the nucleotide sequence for the first nine amino acids was randomized with synonymous codons. This change of downstream sequence of translational initiation codon greatly affected the efficiency of translation. We could isolate clones which greatly increased RT production, and their sequences were compared to those of the low producers. The overproduced protein was purified and was shown to have RT activity.

• BMB Reports
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• v.35 no.2
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• pp.248-250
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• 2002

Discrimination between the amplification of mRNA and contaminating genomic DNA is a common problem when performing a reverse transcriptase-polymerase chain reaction (RT-PCR). Even after treatment of the samples with DNAse, it is possible that negative controls (samples in which no reverse transcriptase was added) will give positive results. This indicates that there was amplification of DNA, which was not generated during the reverse transcriptase step. The possibility exists that Taq DNA polymerase acts as a reverse transcriptase, generating cDNA from RNA during the PCR step. In order to test this hypothesis, we incubated samples with a DNAse-free RNAse after the cDNA synthesis. Comparison of the results that were obtained from these samples (incubated with or without DNAse-free RNAse) confirms that the reverse transcriptase activity of Taq DNA polymerase I is a possible source of false positive results when performing RT-PCR from intronless genes. Moreover, we describe here a simple and rapid method to overcome the false positive results that originate by this activity of Taq polymerase.

• Tuberculosis and Respiratory Diseases
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• v.38 no.1
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• pp.25-33
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• 1991

The immune staus is known to be decreased in malignant disease and radiation therapy (RT), used as a therapeutic tool, further decrease this-attenuated immune status. We measured the number of peripheral lymphocytes, its subsets and lymphoblast transformation for PPD, PHA, monoclonal antibodies including anti-CD3 and anti-CD2 before and after RT in 19 patients with squamous cell lung cancer to search the fine mechanism behind the RT-induced attenuation of lymphoblast transformtion for mitogens and antigen. The results were as follows; 1) The number of lymphocytes and its subsets decreased significantly after RT, but the percentages of lymhocyte subsets did not change aftr RT except interleukin-2 receptor positive T lymphocytes. 2) The function of lymphoctes, measured by lymphoblast tranformation for PHA and PPD, decrased after RT and the compositions of PBMC used for lymphoblast transformtion were not different before and after RT. 3) The mitosis of lymphocytes to anti-CD2 or anti-CD3 decreased significantly after RT. And IL-2 plus anti-CD3 increased the mitosis than that of anti-CD3 only after RT, but before RT there was no difference. In conclusion, we suggested the fine mechanism behind the RT-induced attenuation of immune response might be the dysfunction of lymphocytes in terms of impaired synthesis of IL-2 rather than the decrease of circulating lymphocyte numbers.

• Restorative Dentistry and Endodontics
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• v.34 no.5
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• pp.430-441
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• 2009

The purpose of this study was to characterize functional distinction between human dental pulp cells(PC) and periodontal ligament cells(PDLC) using cDNA micro array assay and to confirm the results of the microarray assay using RT-PCR. 3 genes out of 51 genes which were found to be more expressed(>2 fold) in PC were selected, and 3 genes out of 19 genes which were found to be more expressed(>2 fold) in PDLC were selected for RT-PCR as well. According to this study, the results were as follows: 1. From the micro array assay, 51 genes were more expressed (2 fold) from PC than PDLC. 2. RT-PCR confirmed that ITGA4 and TGF ${\beta}2$ were more expressed in PC than in PDLC 3. From the micro array assay, 19 genes were more expressed (2 fold) from PDLC than PC. 4. RT-PCR confirmed that LUM, WISP1. and MMP1 were more expressed in PDLC than in PC. From the present study, different expression of the genes between the PC and PDLC were characterized to show the genes which play an important role in dentinogenesis were more expressed from PC than PDLC, while the genes which were related with collagen synthesis were more expressed from PDLC than PC.

• Journal of Periodontal and Implant Science
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• v.34 no.2
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• pp.345-356
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• 2004

The triclosan was shown to have anti-microbial and anti-inflammatory effect with inhibition of inflammatory mediators such as prostaglandin $E_2(PGE_2)$. The purpose of this study was to elucidate whether and how $PGE_2$ could be inhibited by triclosan in human gingival fibroblast. Human gingival fibroblast-1 cells (ATCC CRL2014) were pre-treated for 1 hour with triclosan (0.001 ${\mu}/ml{\sim}10$ ${\mu}/ml$) and then stimulated with $TNF-{\alpha}$ (1.0 ng/ml). $PGE_2$ synthesis was evaluated by ELISA and gene expression of COX-1 and COX-2 was evaluated by RT-PCR after $TNF-{\alpha}$, triclosan, and NS-398 (COX-2 inhibitor, 5, ${\mu}M$) and/ or cycloheximide (protein synthesis inhibitor, 2 ${\mu}g/ml$). Triclosan was cytotoxic to human gingival fibroblasts in the concentration higher than 1.0 ${\mu}g/ml$ for longer than 24 hours in tissue culture. The $PGE_2$ synthesis was inhibited by triclosan in dose-dependent manner. Greater COX-2 mRNA suppression was observed with triclosan (0.1 ${\mu}g/ml$) than with $TNF-{\alpha}$ alone, without change in COX-1 gene expression. Inhibitory effects of triclosan on $PGE_2$ synthesis disappeared in presence of cycloheximide. This study suggests that triclosan inhibit prostaglandin $E_2$ at the level of COX-2 gene regulation and require de novo protein synthesis.

• Journal of the Korea Society of Computer and Information
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• v.3 no.4
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• pp.44-48
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• 1998

In this paper proposed Component Synthesis Algorithm(CSA) for mapping described HDL to RT component of given library. CSA transform I/O variables of HDL and relation of operators to control/data flow graph(CDFG) that consists of graph, reduce the size of graph, compute the cost, the bound, and the method that use compatibility graph(CG), and then mapping to component. Component synthesis used branch-and-bound algorithm. The result that synthesis using CSA algorithm was proved that this result and the cost of the manual were indentified.

• Proceedings of the Korea Institute of Convergence Signal Processing
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• 2001.06a
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• pp.73-76
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• 2001

High-level synthesis generates a structural design that implements the given behavior and satisfies design constraints for area, performance, power consumption, packaging, testing and other criteria. Thus, high-level synthesis generates that register-transfer(RT) level structure from algorithm level description. High-level synthesis consist of compiling, partitioning, scheduling. In this paper, we proposed the efficient scheduling algorithm that find the number of the functional unit and scheduling into the minimum control step with silicon area resource constrained.

• Research in Plant Disease
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• v.23 no.2
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• pp.193-201
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• 2017

Major tomato viruses in Korea are Tomato chlorosis virus (ToCV), Tomato spotted wilt virus (TSWV), Cucumber mosaic virus (CMV), Pepper mottle virus (PepMoV), and Tomato mosaic virus (ToMV). RT-PCR conditions for the viruses were examined, especially in primer set and RT-PCR mixture. Total 46 primer sets from the unique sequence of the viruses were tested for nonspecific background products in a RT-PCR mixture without template. Among them 16 primer sets were applied to healthy tomato RNA, resulting the compatibility between RT-PCR mixture and primer set influenced RT-PCR to reduce nonspecific background products. Based on the combinations among cDNA synthesis parameters and RT-PCR mixtures, two reaction mixtures were finally selected for ToCV detection. The condition allowed to determine more specific primer sets; C029 (ToCV), C072 (TSWV), C070 (CMV), C048 (PepMoV), and C065 (ToMV). These primer sets are expected to be of use to specific detection of the major viruses in tomato plants.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.41 no.5
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• pp.107-114
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• 2004

In this paper, we present the architecture design of CDMA/TDMA modem chipset for wireless telemetry system. The wireless telemetry system a measuring data collecting system from many RTs(Remote Terminal) installed at the specific area using wireless communication technology. It consists of CU single CU (Central Unit) for collecting data and a large amount of RTs for transmitting the measuring data. We propose the hardware architecture of the modem for RT and CU. We also design those modem using Verilog HDL and synthesis them using Synopsys$^{TM}$ CAD tool. The modem of RT is implemented with 27K gates and that of CU is implemented around 220k gates using 0.6${\mu}{\textrm}{m}$ CMOS standard cell. The proposed system is implemented and tested using Altera$^{TM}$ FPGA.PGA.

• Journal of the Korean Institute of Telematics and Electronics A
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• v.31A no.5
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• pp.149-157
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• 1994

This paper Presents an algorithm for synthesis of sequential statements described at RT level VHDL. The proposed algorithm transforms sequential statements in VHDL into data-flow description consisting of concurrent statements by local and global dependency analysis and output dependency elimination. Transformation into concurrent statements makes it possible to reduce the cost of the synthesized hardwares, thus to get optimal synthesis results that will befit the designer 's intention. This algorithm has been implemented on VSYN and experimental results show that more compact gate-level hardwares are generated compared with Power View system from ViewLogic and Design Analyzer from Synopsys.