H
Hiroyuki Okada
Researcher at Okayama University
Publications - 870
Citations - 13191
Hiroyuki Okada is an academic researcher from Okayama University. The author has contributed to research in topics: Medicine & Cancer. The author has an hindex of 49, co-authored 790 publications receiving 11050 citations. Previous affiliations of Hiroyuki Okada include Memorial Hospital of South Bend.
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Methamphetamine-related psychiatric symptoms and reduced brain dopamine transporters studied with PET.
Yoshimoto Sekine,Masaomi Iyo,Yasuomi Ouchi,Tsutomu Matsunaga,Hideo Tsukada,Hiroyuki Okada,Etsuji Yoshikawa,Masami Futatsubashi,Nori Takei,Norio Mori +9 more
TL;DR: The findings suggest that longer use of methamphetamine may cause more severe psychiatric symptoms and greater reduction of dopamine transporter density in the brain, and show that the dopamine transporter reduction may be long-lasting, even if methamphetamine use ceases.
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Brain activation during maintenance of standing postures in humans
TL;DR: The findings confirmed that the cerebellar vermis efferent system plays an important role in maintenance of standing posture and suggested that the visual association cortex may subserve regulating postural equilibrium while standing.
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Brain Serotonin Transporter Density and Aggression in Abstinent Methamphetamine Abusers
Yoshimoto Sekine,Yasuomi Ouchi,Nori Takei,Etsuji Yoshikawa,Kazuhiko Nakamura,Masami Futatsubashi,Hiroyuki Okada,Yoshio Minabe,Katsuaki Suzuki,Yasuhide Iwata,Kenji J. Tsuchiya,Hideo Tsukada,Masaomi Iyo,Norio Mori +13 more
TL;DR: Protracted abuse of methamphetamine may reduce the density of the serotonin transporter in the brain, leading to elevated aggression, even in currently abstinent abusers.
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Endoscopic submucosal dissection for early gastric cancer: results and degrees of technical difficulty as well as success.
Atsushi Imagawa,Hiroyuki Okada,Yoshiro Kawahara,Ryuta Takenaka,Jun Kato,Hirofumi Kawamoto,Shigeatsu Fujiki,Rie Takata,Tadashi Yoshino,Yasushi Shiratori +9 more
TL;DR: The difficulty of ESD depends on the location and size of the lesion, as well as on the presence of ulceration, and it is recommended that trainees should begin by carrying out ESD on lesions with a diameter of less than 20 mm without ulcers that are located in the lower third of the stomach.
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Differences between right- and left-sided colon cancer in patient characteristics, cancer morphology and histology.
Toru Nawa,Jun Kato,Hirofumi Kawamoto,Hiroyuki Okada,Hiroshi Yamamoto,Hiroyuki Kohno,Hisayuki Endo,Yasushi Shiratori +7 more
TL;DR: The clinical and biological differences between right‐ and left‐sided colon cancers have been widely debated, but close analyses of these clinical differences, based on large‐scale studies, have been scarcely reported.