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UVA1 induces the formation of 8-hydroxy-2'-deoxyguanosines (8-OH-dGs) and cyclobutane pyrimidine dimers (CPDs) in the cellular genome. However, the relative contribution of each type of damage to the in vivo genotoxicity of UVA1 has not been clarified. We irradiated living mouse skin with 364-nm UVA1 laser light and analyzed the DNA damage formation and(More)
  • K Hieda
  • 1994
The recent development of irradiation systems using synchrotron radiation (SR) as a source is enabling researchers to obtain intense monochromatic photons having a narrow bandwidth in the vacuum-UV (VUV) and soft X-ray regions. We can thus systematically study the photon energy dependence of DNA damage formation in these energy regions. The photon energy(More)
Using a synchrotron irradiation system pBR322 plasmid DNA was irradiated under vacuum by monochromatic X-rays having five specific photon energies (2.147, 2.153, 2.159, 2.168 and 2.199 keV) both on and off the K-absorption peak (2.153 keV) of phosphorus. The single- and double-strand breaks (ssb and dsb) were measured as conversions of the closed circular(More)
The scission of pentadeoxythymidylic acid, d(pT)5, by monochromatic soft X-rays on (2153 eV) and below (2147 eV) the K-shell absorption peak of phosphorus was studied as a model of strand breakage in DNA. Samples dried on glass plates were irradiated by monochromatic soft X-rays in vacuo, and the products were analysed by HPLC. The main products, in(More)
The effects of K-shell absorption of phosphorus atoms on yeast cells were investigated using synchrotron X-rays that were tuned to the resonance absorption peak (2153 eV). Three types of cellular effect (cell inactivation, induction of gene conversion at the trp-5 locus, and cell membrane impairment (changes in the permeability] were measured. It was(More)
A rapid and simple yeast transformation procedure has been developed using colonies on agar plates. Saccharomyces cerevisiae SHY3 cells were picked up from colonies on YPD plates grown freshly or stored at 4 °C and incubated with M13RK9-T DNA at 30 °C for 1–2 h in a solution of Li+, Ca2+, Mg2+, triacetin and polyethylene glycol. About 3,500 transformants(More)
We investigated the wavelength dependence of cyclobutane thymine dimer and (6-4)photoproduct induction by monochromatic UV in the region extending from 150 to 365 nm, using an enzyme-linked immunosorbent assay with two monoclonal antibodies. Calf thymus DNA solution was irradiated with 254-365 nm monochromatic UV from a spectrograph, or with 220-300 nm(More)
Using an electron storage ring as a source of radiation, the wavelength dependence of inactivation and membrane damage in yeast cells (Saccharomyces cerevisiae) was investigated in the range from 145 to 254 nm, with special reference to the effects of vacuum-uv radiation. The cells were irradiated on a Millipore filter in a moist chamber filled with water(More)