This invention relates to glutamine:fructose-6-phosphate amidotransferase, or its partial peptide or a salt thereof; a DNA coding for the protein; a recombinant vector; a transformant; a method for producing the protein; a pharmaceutical composition comprising the protein, its partial peptide or a salt thereof; and an antibody against the protein or its partial peptide. The distribution server includes the obtained rights administration database that stores information regarding rights to receive distribution of contents, and the history database that stores information regarding contents that have been distributed to the user in the past. The optical fibers may be used in biomedical applications and can be inserted in the body as transmissive media. A continuous pressure is provided against the first surface of the substrate in the first part and second part of the path and therebetween. The jaws of the first clip have cushions which abuttingly contact the eyewear when gripped by the jaws of the first clip. A laser beam is irradiated onto an oxide single crystal to from an optical waveguide portion defined by laser working faces, which are then subjected to a wet etching process using, for example, a strong alkaline solution.