The Tokyo High Court on Tuesday rejected an appeal by a senior member of Aum Shinrikyo, upholding a lower court decision that sentenced him to eight years in prison for modifying a van so it could be used for spraying sarin and building a plant to produce the deadly nerve gas.Wakashio Togasi, 38, was convicted of abetting murder by helping the cult build the sarin-spraying truck, which was used in the June 1994 nerve gas attack in Matsumoto, Nagano Prefecture, and of plotting murder by conspiring with other cultists to build a sarin plant between November 1993 and December 1994 in the cult's headquarters in Kamikushiki, Yamanashi Prefecture.The defendant knew about the cult's plan to disburse sarin, presiding Judge Tadaharu Kanda pointed out, noting the plant was fully capable of producing large volumes of the deadly gas.Togashi had pleaded innocent to the charges, saying he did not know the cult would release a deadly chemical and claiming the plant was incapable of producing sarin.