Studies of biological effects of vacuum ultraviolet radiation above 50 nm.

安装在东京大学固体物理研究所SOR环BL-5的用于放射生物学研究的单色真空-紫外线(VUV)辐照系统进行了以下改进。首先在单色仪的光栅室中增加一个50 1/S离子泵，以获得更好的真空度。结果，由于光栅劣化引起的光强度的降低变得可以忽略不计。其次，用一种新的高性能型号取代了快门，可以将照射时间控制在0.25秒。第三，改进了计算机程序。在1986-1987财政年度进行了以下实验：Dry样品：寡核苷酸，脱磷(Da)_2，在55-190 nm范围内照射并进行薄层分析(T.Ito等人)。用琼脂糖凝胶电泳法检测DNA单链断裂(80~255 nm)，用高效液相色谱法检测碱基释放(150~190 nm)，用抗胸腺嘧啶二聚体单抗检测胸腺嘧啶二聚体(150~260 nm)。测定了小林克氏杆菌对溶菌酶的灭活时间为60~190 nm，前泽氏杆菌对T_1噬菌体的灭活时间为50~260 nm，竹节杆菌对枯草杆菌孢子的灭活时间为50~300 nm。还进行了T.Megumi对脂质双层的常规吸收测量和T.Inagaki对有机薄膜的光声光谱测量。解决方案：用A.Minegishi的自旋捕捉法测量了VUV产生的OH自由基。K.Takakura对二核苷酸CPC的光解150-254 nm。

The monochromatic vacuum-ultraviolet (VUV) irradiation system for radiobiological studies installed at BL-5 of the SOR-RING, the Institute for Solid State Physics, the University of Tokyo, was improved as follows. Firstly a 50 1/s ion pump was added to the grating chamber of the monochromator to obtain better vacuum. As a result, decrease of light intensity due to deteriotation of the grating became negligible. Secondly a shutter was replaced by a new high-performance type, which can control irradiation time down to 0.25 sec. Thirdly computor program was improved. The following experiments were performed during 1986 and 1987 fiscal years.Dry samples: Oligonucleotide, dephospho (dA)_2, was irradiated over 55 to 190 nm range and analyzed thin-layer chromatography (T. Ito et al.). Following DNA damages were measured: single-strand breaks detected by agarose gel electrophoresis by K. Hieda (80-255 nm), base release detected by HPLC by K. Hieda (150-190 nm) and thymine-dimer detected by monoclonal antibody by O. Nikaido (150-260 nm). Inactivation of lysozyme by K. Kobayashi for 60-190 nm, inactivation of T_1 phage by H. Maezawa for 50-260 nm and inactivation of Batillus subtilis spore by N. Munakata for 50-300 nm were measured. Conventional absorption measurement on lipid bilayer by T. Megumi and photoacoustic spectrometry of organic film by T. Inagaki were also performed.Solution: OH radical produced by VUV was measured by the spin-trapping method by A. Minegishi. Photolysis of dinucleotide, CpC, by K. Takakura for 150-254 nm.