• Parasites, Hosts and Diseases
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• v.33 no.4
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• pp.357-364
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• 1995

The protozoan parasite, Entcmoeba histoIWticc, is one of major causative agents of intestinal disease all over the world. In acute experimental infection, the early host response to 5. histoIHtica is characterized by an infiltration of neutrophils. However, the chemotactic signal for this response is not well known. Based on the (jading that human epithelial cells produce the potent neutrophil chemoattractant and activator, interleukin-8 (IL-8), IL-8 gene expression was examined thoroughly in human colon epithelial cells exposed to 5. histolvtica trophozoites. Cellular RNAs were extracted from HT-29 or Caco-2 human colon epithelial cells exposed to 5. histoLvtica trophozoites for 30 minutes, 1 and 3 hours. IL-8 mRNA transcripts were measured by reverse transcriptional polprnerase chain reaction (RT-PCR) using synthetic standard RNA. The number of IL-8 mRNA molecules increased from 30 minutes to 3 hours of exposure period, reaching 3.1 H 107 molecules/ug of total RNA. Expression pattern of IL-8 mRNA transcripts was parallel to the amounts of IL-8 protein measured by enzyme-linked immunosorbent assay (ELISA) . Lysates of 5. histoIVtica also induced expression of mRNA for IL-8 in colon epithelial cells. These results sugf:esc that acute inflammatory reaction by 5. histoIVticc may be initially triggered by proinflammatory cytokines such as IL-8 secreted from epithelial cells of the colon.

• Journal of Microbiology and Biotechnology
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• v.15 no.3
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• pp.595-602
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• 2005

A one-step real-time quantitative RT-PCR assay in combination with automated RNA extraction was evaluated for routine testing of HCV RNA in the laboratory. Specific primers and probes were developed to detect 302 bp on 5'-UTR of HCV RNA. The assay was able to quantitate a dynamic linear range of $10^7-10^1$ HCV RNA copies/reaction ($R^2=0.997$). The synthetic HCV RNA standard of $1.84{\pm}0.1\;(mean{\pm}SD)$ copies developed in this study corresponded to 1 international unit (IU) of WHO International Standard for HCV RNA (96/790 I). The detection limit of the assay was 3 RNA copies/reaction (81 IU/ml) in plasma samples. The assay was comparable to the Amplicor HCV Monitor (Monitor) assay with correlation coefficient r=0.985, but was more sensitive than the Monitor assay. The assay could be completed within 3 h from RNA extraction to detection and data analysis for up to 32 samples. It allowed rapid RNA extraction, detection, and quantitation of HCV RNA in plasma samples. The method provided sufficient sensitivity and reproducibility and proved to be fast and labor-saving, so that it was suitable for high throughput HCV RNA test.

• Korean Journal of Microbiology
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• v.2 no.1
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• pp.1-11
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• 1964

Yung Nok Lee (Dept. of Biology, Korea University) : Studies on the phosphate metabolism in Chlorella, with special reference to polyphosphate. Kor. J. Microbiol., Vol.2, No.1, p1-11 (1964). 1. Uniformly $^{32}P$-labeled Chlorella cells which were irradiated with Cobalt-60 gamma-rays of about 70, 000 $\gamma$ dose, were further grown in a standard "cold" medium ("hot".rarw."cold"), and some portions of the algae were taken out at the begining of, and at intervals during the culture, and subjected to analyze the contents of $^{32}P$- and total P in various fractions of the cell materials. Results obtained were compared with those of nonirradiated normal cells. 2. Amounts of phosphate in various fractions of the nonirradiated normal Chlorella cells were measured using uniformly $^{32}P$--labeled cells. Analysis of the $^{32}P$--labeled algal cells showed that the highest value in P-content was the fraction of RNA followed by those of lipid, polyphosphate "C" polyphosphate "B", DNA, nucleotidic labile phosphate compounds, polyphosphate "A" and protein. It was observed that content of total polyphosphates in a single Chlorella cell was almost equal to RNA-P content in the cell, and the amount of RNA-P was almost equal to ten times of DNA-P content. 3. When the $^{32}P$--labeled algae which were irradiated with gamma-rays were grown in a normal "cold" medium, phosphate contents in the fraction of DNA, nucleotidic labile phosphate compounds and protein decreased markedly, while the contents of phosphate in the fractions of polyphosphate "C" and potyphosphate "B" increased in comparison with those of unirradiated normal cells. So, it was considered that the pretreatment of above mentioned dose of gamma-ray inhibited DNA and protein synthesis from polyphosphate in Chlorella cells. 4. Proceeding the culture of $^{32}P$--labeled Chlorella in a "cold" standard medium, whose synthetic activity of DNA and protein from polyphosphate was disturded by gamma-ray irradiation, the amounts of $^{32}P$-in the fraction of polyphosphate "C" increased, in contrast with those of polyphosphate "B" fraction. According to these experimental results, it was inferred that polyphosphate "B" could transform into polyphosphate "C" in normal growing Chlorella cells.sults, it was inferred that polyphosphate "B" could transform into polyphosphate "C" in normal growing Chlorella cells.ing Chlorella cells.

• BMB Reports
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• v.29 no.2
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• pp.122-126
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• 1996

A series of oligonucleotides were synthesized by automatic DNA synthesizer. The purity of crude products was checked and their molecular weights determined by matrix assisted laser desorption ionization mass spectrometry (MALDI-MS) with an accuracy of better than 0.05% deviation even without using an internal standard. This mass determining technology in combination with partial digestion of oligonucleotides by 5'- and 3'-exonuclease provides a straightforward and simple method to obtain sequence information of oligonucleotides. The extension of this technology to the sequencing of modified oligonucleotides and genomic DNA and RNA might become possible.