Impact of gamma irradiation on the transformation efficiency for extracellular plasmid DNA

Ishii, Nobuyoshi; Sakashita, Testuya; Takeda, Hiroshi; Kubota, Yoshihisa; Fuma, Shoichi; Doi, Masahiro; Takahashi, Sentaro

doi:10.1016/j.jenvrad.2007.04.002

Cited by 5 publications

(6 citation statements)

References 29 publications

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“…(3) The qualitative conclusion that transformation efficiency decreases with the increase in radiation dose, as stated elsewhere, 8 could now be quantitatively rephrased as transformation efficiency decreases directly proportional to the square of the radiation dose (Fig. 3).…”

Section: Discussionmentioning

confidence: 62%

“…As pointed out elsewhere, 8 however, it is also important to study alterations in physical structures of abiotic materials (such as extracellular DNA) because ecosystems consist of both biotic and abiotic components. Some bacteria can develop competence for extracellular DNA uptake and express the foreign genetic material, 9,10 indicating that extracellular DNA serves as a material determining bacterial characteristics and their genetic functions through natural genetic transformation.…”

Section: Uranium In Water -Burden On Biotic and Abiotic Materialsmentioning

confidence: 99%

“…DNA fragments are produced by multiple double strand breaks (DSBs), and these strand breaks are closely related to the decrease in the transformation efficiency for extracellular plasmid DNA, as suggested elsewhere. 8 It is our hope to provide guidelines for the planning and implementation of biological monitoring, particularly for an earlier detection of contaminants in water bodies.…”

Section: Uranium In Water -Burden On Biotic and Abiotic Materialsmentioning

confidence: 99%

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Fragmentation of extracellular DNA by long-term exposure to radiation from uranium in aquatic environments

et al. 2012

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Persistent harmful scenarios associated with disposal of radioactive waste, high-background radiation areas and severe nuclear accidents are of great concern regarding consequences to both human health and the environment. Of particular concern is the extracellular DNA in aquatic environments contaminated by radiological substances. Strand breaks induced by radiation promote decrease in the transformation efficiency for extracellular DNA. The focus of this study is the quantification of DNA damage following long-term exposure (over one year) to low doses of natural uranium (an alpha particle emitter) to simulate natural conditions, since nothing is known about alpha radiation induced damage to extracellular DNA. A high-resolution Atomic Force Microscope was used to evaluate DNA fragments. Double-stranded plasmid pBS as a model for extracellular DNA was exposed to different amounts of natural uranium. It was demonstrated that low concentrations of U in water (50 to 150 ppm) produce appreciable numbers of double strand breaks, scaling with the square of the average doses. The importance of these findings for environment monitoring of radiological pollution is addressed.

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Section: Discussionmentioning

confidence: 62%

Section: Uranium In Water -Burden On Biotic and Abiotic Materialsmentioning

confidence: 99%

Section: Uranium In Water -Burden On Biotic and Abiotic Materialsmentioning

confidence: 99%

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Fragmentation of extracellular DNA by long-term exposure to radiation from uranium in aquatic environments

et al. 2012

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“…The examined glucocorticosteroid drugs were thermally sterilized according to the Polish Pharmaceutical Norms [1][2][3] at the following temperatures and times: 160°C during 120 min, 170°C during 60 min, and 180°C during 30 min. Powdered drug samples were heated in a hot air oven with air circulation.…”

Section: Thermal Sterilizationmentioning

confidence: 99%

“…The most popular methods of drug sterilization are radiosterilization by gamma irradiation in the dose of 25 kGy and thermal heating of thermolabile drugs at 160, 170, and 180°C [1][2][3][4][5][6][7][8][9][10]. Radiative sterilization needs expensive sources of radiation and protection of people during the drug production.…”

mentioning

confidence: 99%

Application of EPR Spectroscopy for Examination of Free Radical Formation in Thermally Sterilized Betamethasone, Clobetasol, and Dexamethasone

Kościelniak-Ziemniak

Pilawa

2012

Appl Magn Reson

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Paramagnetic centers in the three glucocorticosteroid drugs, such as betamethasone, clobetasol, and dexamethasone, were examined by the use of X-band (9.3 GHz) electron paramagnetic resonance (EPR) spectroscopy. Glucocorticosteroid drugs were sterilized according to the norms at 160°C (120 min), 170°C (60 min), and 180°C (30 min). Free radical properties, types, and concentrations in the individual glucocorticosteroids were compared. The lineshape and parameters of EPR curves recorded in the range of the microwave power of 0.7-70 mW were tested. The non-heated drugs were diamagnetic. Free radicals were formed in clobetasol and dexamethasone drugs during process of their thermal sterilization, while free radicals were not detected in thermally sterilized betamethasone. Fast spin-lattice relaxation processes existed in heated clobetasol and dexamethasone. Their EPR lines were homogeneously broadened. A complex free radical system characterized these two drugs. Optimal conditions of sterilization of glucocorticosteroids were obtained. Betamethasone may be sterilized at 160, 170, and 180°C. Clobetasol may be sterilized at 160 and 170°C. Dexamethasone may be sterilized at 170 and 180°C.

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Gamma radiation coupled ADP-ribosyl transferase activity of Pseudomonas aeruginosa PE24 moiety

Morgan

Saleh

Farrag

et al. 2023

Appl Microbiol Biotechnol

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The ADP-ribosyl transferase activity of P. aeruginosa PE24 moiety expressed by E. coli BL21 (DE3) was assessed on nitrobenzylidene aminoguanidine (NBAG) and in vitro cultured cancer cell lines. Gene encoding PE24 was isolated from P. aeruginosa isolates, cloned into pET22b( +) plasmid, and expressed in E. coli BL21 (DE3) under IPTG induction. Genetic recombination was confirmed by colony PCR, the appearance of insert post digestion of engineered construct, and protein electrophoresis using sodium dodecyl-sulfate polyacrylamide gel (SDS-PAGE). The chemical compound NBAG has been used to confirm PE24 extract ADP-ribosyl transferase action through UV spectroscopy, FTIR, c13-NMR, and HPLC before and after low-dose gamma irradiation (5, 10, 15, 24 Gy). The cytotoxicity of PE24 extract alone and in combination with paclitaxel and low-dose gamma radiation (both 5 Gy and one shot 24 Gy) was assessed on adherent cell lines HEPG2, MCF-7, A375, OEC, and Kasumi-1 cell suspension. Expressed PE24 moiety ADP-ribosylated NBAG as revealed by structural changes depicted by FTIR and NMR, and the surge of new peaks at different retention times from NBAG in HPLC chromatograms. Irradiating recombinant PE24 moiety was associated with a reduction in ADP-ribosylating activity. The PE24 extract IC50 values were < 10 μg/ml with an acceptable R2 value on cancer cell lines and acceptable cell viability at 10 μg/ml on normal OEC. Overall, the synergistic effects were observed upon combining PE24 extract with low-dose paclitaxel demonstrated by the reduction in IC50 whereas antagonistic effects and a rise in IC50 values were recorded after irradiation by low-dose gamma rays. Key points • Recombinant PE24 moiety was successfully expressed and biochemically analyzed. • Low-dose gamma radiation and metal ions decreased the recombinant PE24 cytotoxic activity. • Synergism was observed upon combining recombinant PE24 with low-dose paclitaxel.

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Impact of gamma irradiation on the transformation efficiency for extracellular plasmid DNA

Cited by 5 publications

References 29 publications

Fragmentation of extracellular DNA by long-term exposure to radiation from uranium in aquatic environments

Fragmentation of extracellular DNA by long-term exposure to radiation from uranium in aquatic environments

Application of EPR Spectroscopy for Examination of Free Radical Formation in Thermally Sterilized Betamethasone, Clobetasol, and Dexamethasone

Gamma radiation coupled ADP-ribosyl transferase activity of Pseudomonas aeruginosa PE24 moiety

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