• Title, Summary, Keyword: R249S

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Prevalence of Aflatoxin Induced p53 Mutation at Codon 249 (R249s) in Hepatocellular Carcinoma Patients with and without Hepatitis B Surface Antigen (HBsAg)

  • Chittmittrapap, Salyavit;Chieochansin, Thaweesak;Chaiteerakij, Roongruedee;Treeprasertsuk, Sombat;Klaikaew, Naruemon;Tangkijvanich, Pisit;Komolmit, Piyawat;Poovorawan, Yong
    • Asian Pacific Journal of Cancer Prevention
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    • v.14 no.12
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    • pp.7675-7679
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    • 2013
  • Background: A missense mutation in exon 7 (R249S) of the p53 tumor suppressor gene is characteristic of aflatoxin B1 (AFB1) exposure. AFB1 is believed to have a synergistic effect on hepatitis virus B (HBV) carcinogenesis. However, results of studies comparing R249S prevalence among patients are conflicting. The aim of this study was to determine the prevalence of the R249S mutation in hepatocellular carcinoma (HCC) patients with or without positive HBsAg. Materials and Methods: Paraffin embedded liver tissues were obtained from 124 HCC patients who underwent liver resection and liver biopsy in King Chulalongkorn Memorial Hospital. Restriction fragment length polymorphism (RFLP) was utilized to detect the R249S mutation. Positive results were confirmed by direct sequencing. Results: Sixty four (52%) patients were positive for HBsAg and 18 (15%) were anti-HCV positive. 12 specimens tested positive by RFLP. Ten HCC patients (8.1%) were confirmed to be R249S positive by Sanger sequencing (AGG to AGT). Out of these 10, six were HBsAg positive, and out of the remaining 4, two were anti-HCV positive. The R249S prevalence among HCC patients with positive HBsAg was 9.4% compared to 6.7% for HBsAg negative samples. Patients with the R249S mutation were younger ($55{\pm}10$ vs $60{\pm}13$ year-old) and tended to have a more advanced Edmonson-Steiner grade of HCC, although differences did not reach statistical significance. Conclusions: Our study shows moderate prevalence of aflatoxin B1-related p53 mutation (R249S) in HCC with or without HBsAg. HBsAg positive status was not associated with R249S prevalence.

Hepatitis B Virus Genetic Variation and TP53 R249S Mutation in Patients with Hepatocellular Carcinoma in Thailand

  • Thongbai, Chureeporn;Sa-nguanmoo, Pattaratida;Kranokpiruk, Pavanrat;Poovorawan, Kittiyod;Poovorawan, Yong;Tangkijvanich, Pisit
    • Asian Pacific Journal of Cancer Prevention
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    • v.14 no.6
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    • pp.3555-3559
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    • 2013
  • Chronic hepatitis B virus (HBV) infection and dietary exposure to aflatoxin B1 (AFB1) are major risk factors for hepatocellular carcinoma (HCC). The aim of this study was to evaluate the role of HBV genetic variation and the R249S mutation of the p53 gene, a marker of AFB1-induced HCC, in Thai patients chronically infected with HBV. Sixty-five patients with and 89 patients without HCC were included. Viral mutations and R249S mutation were characterized by direct sequencing and restriction fragment length polymorphism (RFLP) in serum samples, respectively. The prevalences of T1753C/A/G and A1762T/G1764A mutations in the basal core promotor (BCP) region were significantly higher in the HCC group compared to the non-HCC group. R249S mutation was detected in 6.2% and 3.4% of the HCC and non-HCC groups, respectively, which was not significantly different. By multiple logistic regression analysis, the presence of A1762T/G1764A mutations was independently associated with the risk of HCC in Thai patients.

THE RADIAL DERIVATIVES ON WEIGHTED BERGMAN SPACES

  • Kang, Si-Ho;Kim, Ja-Young
    • Communications of the Korean Mathematical Society
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    • v.18 no.2
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    • pp.243-249
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    • 2003
  • We consider weighted Bergman spaces and radial derivatives on the spaces. We also prove that for each element f in B$\^$p, r/ there is a unique f in B$\^$p, r/ such that f is the radial derivative of f and for each f$\in$B$\^$r/(i), f is the radial derivative of some element of B$\^$r/(i) if and only if, lim f(tz)= 0 for all z$\in$H.

Development of an Enzyme Electrode Biosensor for Lactic Acid Bacteria (효소 전극을 이용한 유산균 측정 바이오센서 개발)

  • Park T. S.;Cho S. I.
    • Journal of Biosystems Engineering
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    • v.30 no.4
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    • pp.249-253
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    • 2005
  • This study was carried out to develop enzyme biosensor for lactic acid bacteria. Lactic acids produced by lactic acid bacteria (LAB) was measured and good correlation $R^2=0.98$ between LAB count and lactic acids concentration was found. Hydrogen ion produced by L-lactate dehydrogenase (L-LDH) was measured by a potentiometer. Glutamic-pyruvic transminase (GPT) was used for eliminating inhibitor in the reaction. Polyacrylamide gel was used for immobilizing matrix of the sensor. The biosensor was tested and showed good feasibility with $R^2=0.99$ on validation.

Scanning Electron Microscopic Study of Slime Formations in a Water Injection Station of Oil India Limited in Assam, India

  • Bhagobaty, Ranjan K.;Purohit, S.;Nihalani, M.C.
    • Applied Microscopy
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    • v.45 no.4
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    • pp.249-253
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    • 2015
  • Microorganisms specifically groups of bacteria exhibiting physiological activities of production of acids are a major cause of concern because of their ability to induce corrosion in oil field pipelines and metal systems involved in water handling. Water Injection Stations as a means of secondary recovery from existing oil producing reservoirs, are often employed in most upstream oil and gas industries to ensure replenishment of voidage, maintenance of reservoir pressure and optimization of crude emulsion throughput. In the present study, scanning electron microscopy of macroscopic orange coloured slime formations sampled from leaking valves on the flow-lines of a Water Injection Stations of Oil India Limited revealed the presence of filamentous bacterial mats in association with diatoms. The species composition of the acidic slime formations from the sampled locations reveal the possible role of acid producing iron oxidizing bacteria (IOB) like Acidithiobacillus ferrooxidans in association with Gomphonema sp. in creating conditions for bio-corrosion.

Effect of Chitosan Acetate on Bacteria Occurring on Neungee Mushrooms, Sarcodon aspratus

  • Park, Bom-Soo;Koo, Chang-Duck;Ka, Kang-Hyeon;Lee, Young-Nam
    • Mycobiology
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    • v.36 no.4
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    • pp.249-254
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    • 2008
  • Minimal growth inhibitory concentrations (MICs) of chitosan acetate (M.W. 60 kDa) on heterotrophic bacteria (strains MK1, S, and R) isolated from the soft-rotten tissues of Neungee mushroom (Sarcodon aspratus) were measured. The slimy substance produced by the MK1 strain was responsible for the diseased mushroom’s appearance. The S and R strains were members of the Burkholderia cepacia complex. These strains showed different levels of susceptibility toward chitosan acetate. The MIC of chitosan acetate against the MK1 and S strains was 0.06%. The MIC against the R strain was greater than 0.10%. Survival fractions of the MK1 and S strains at the MIC were $3\;{\times}\;10^{-4}$ and $1.4\;{\times}\;10^{-3}$ after 24 h, and $2\;{\times}\;10^{-4}$ and $7\;{\times}\;10^{-4}$ after 48 h, respectively. Survival fractions of the R strain after 24 and 48 hr at 0.1% chitosan acetate were $1\;{\times}\;10^{-2}$ and $6.9\;{\times}\;10^{-3}$, respectively. Compared to the MK1 and S strains, the low susceptibility of the R stain towards chitosan acetate could be due to the ability of the R strain to utilize chitosan as a carbon source. Thirty-eight percent of Neungee pieces treated in a 0.06% chitosan acetate solution for $2{\sim}3$ second did not show any bacterial growth at 4 days, whereas bacterial growth around untreated mushroom pieces occurred within 2 days. These data suggest that chitosan acetate is highly effective in controlling growth of indigenous microorganisms on Neungee. The scanning electron micrographs of the MK1 strain treated with chitosan revealed a higher degree of disintegrated and distorted cellular structures.

A Long-term Replenishment Contract under (R, S) Policy ((R, S)정책하에서의 장기 보충계약)

  • Kim, Yong Chan;Kim, Jong Soo
    • Journal of Korean Institute of Industrial Engineers
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    • v.30 no.3
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    • pp.241-249
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    • 2004
  • By committing to a long-term replenishment contract, suppliers can mitigate the pressure to find new customers and afford to charge a discounted price to buyers seeking to lower their purchasing costs. In this paper, we develop an analytical model from buyer's perspective for the contracting process to investigate the buyer-supplier interactions. Based on the developed model, we propose an algorithm to derive optimal strategy for the contract. We consider a system with a single buyer and a supplier in a situation where the buyer's inventory is controlled by (R, S) policy under VMI setting. According to the contract, the supplier should replenish the buyer's inventory up to a fixed level every R times during a specified period. The buyer purchases any deficient amount from a spot market at a higher price. We show by computational experiment that our proposed algorithm finds the global optimum solution.

Development of VVVF Inverter Control System for Propulsion System (차량용 VVVF 인버터 제어시스템 개발)

  • Kim, B.S.;Lee, K.C.;Lee, H.S.;Kim, S.W.;Park, Y.C.;Kim, J.H.
    • Proceedings of the KIEE Conference
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    • pp.249-251
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    • 1994
  • This paper introduces an implementation of high performance voltage source inverter system based on 16bit micro-processor and DSP for the application to modem rolling stock traction system. In contrast with other industry oriented inverter system, this system requires precise control action complying with various load condition and high overload capability. An asynchronous PWM generation and 3' pulse mode technology are adopted in order to improve compliant starting torque characteristics at starting phase and soft backward-forward starting motion.

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