Commemorating Professor Takeo Ohnishi

Remembering Professor Ohnishi, I have to think about the time when we first met as graduate students specializing in radiation biology and became friends. We shared a liking for ping-pong and the Chinese language. During congresses, we would leave the main venue and enjoy ourselves. In recent years, we had unfortunately turned in bad company as our position did not allow for it anymore. Not seeing his face at last year’s congress of the Japanese radiation research society puzzled me. I called him, but he did not mention his disease. A phone call about his hospital admission and the news of a serious illness on May the 29 of this year, was thus sudden to me. After battling the disease for a month, he passed away on July 8, at the age of 72. I cannot stop thinking about how this came too soon. I had hoped that he would still be teaching a new generation; his loss has left a hole in my heart. I sincerely pray for his soul. The Bikini Incident caused by a hydrogen bomb test of the American military on Bikini Atoll on March 1, 1954 was the trigger for the establishment of the ‘Radiation Biology laboratory’ with sites at the Science faculties of Kyoto University, Tokyo University, and Osaka University. Professor Ichijirō Honjō lead the schools of both Kyoto and Osaka Universities, with Keiichi Nozu as assistant professor at Osaka (later Professor at Nara Medical University) and his pupil Ohnishi-sensei; and with Mikita Katō as assistant professor (later professor) in Kyoto and a pupil being me. We both were thus pupils of Honjō-sensei. Of the three schools, unfortunately only a small division remains at Kyoto University. The events of the Hiroshima and Nagasaki atomic bombings and the accident at Bikini Atoll, fueled the efforts of many pioneers in the science of radiation effects (medicine, biology, radiation detection and measurement, health physics, environmental biology, etc.). However it was revealed after the Fukushima nuclear power plant accident of March 11, 2011 that there was no close association between the responding radiation effects science researchers, and that development of radiation biomedicine was deficient. In such a situation, the passing of Dr. Takeo Ohnishi who is a pioneer in the development of radiation biomedicine is truly regrettable. When we were graduate students, human resources did not progress as one would have wished because of the ongoing conflicts with student movements at university campuses at the time. There was thus no fertile ground for us researchers who had just left the newly established ‘radiation biology’ laboratory. At that juncture, it was Professor Tsutomu Sugahara and Professor Sōhei Kondo of the medical faculties of Kyoto and Osaka Universities, who lead the way for the establishment of a Radiation Effects Research Institution (RERI), with a Research Exchange Planning Division, nine fixed research divisions, and three visiting divisions. As this endeavor was an opportunity for young researchers looking for employment, it brought us hope and we had to fight for it. As graduate students not awaiting employment, Ohnishi-sensei and I were selected to be members of the preparatory commission and were involved in the writing of funding requests. From that time, I became to see Ohnishi-sensei as a big brother. Thereafter, we had a chance to become colleagues. Masakatsu Horikawa sensei who was an assistant at the Tsutomu Sugawara laboratory at that time became a professor of pharmacology at Kanazawa University and I became his successor. Another post was furthermore available at the Sugawara laboratory. However, Professor Nozu, moved to Nara Medical University, and Ohnishi sensei went with his supervisor to Nara. In the end, Otura Niwa sensei got the position. After that, we decided to proceed with an early establishment of the RERI. The research institution was reduced to a Radiation Biology Center (RBC) with a Research Exchange Planning Division and a few Divisions. A driving force behind the movement for the RBC, was an organization made to integrate all the local Radiation Biology Liaison Conferences with Nozu-sensei as the Chair. In this way, the RBC was established with the enthusiastic efforts of radiologists, radiation biologists, radiation measurement and environmental researchers across the country. After Nozu-sensei retired, Ohnishi sensei became his successor as professor and as chair of the national RBC liaison conference. I trust that all know about his active role. At first, Professor Ohnishi was studying the effects of ultraviolet rays with bacteria and slime molds as research materials. When I came back from an exchange in the USA, I got a post at the research center and became a group leader of ‘Cancer Special Research’. Professor Ohnishi became a fund receiving member of the group, and was able to start cancer research using cell culture as an experimental system. He changed research themes and materials several times, to finally get great results, such as with sporangia formation of slime molds. His flexible research attitude led him to expand his field of research to cancer, hyperthermia, heavy particle beam, astrobiology and low dose rate radiation, topics that are currently intense investigation. In those studies, he had a constant attention on the TP 53 gene regardless of how the research field was expanded. His contributions were exemplary and rendered Ohnishi-sensei into a ‘model educator’. His inputs were extensive and also covered space biology research; I am certain that this unique research theme is thankful to