Shigeru Yamasaki
Shiga University of Medical Science
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Featured researches published by Shigeru Yamasaki.
Legal Medicine | 2009
Shigeru Yamasaki; Izumi Takase; Naoki Takada; Katsuji Nishi
We experienced suicidal hanging cases without a ligature in front of the neck. We conducted several anatomical autopsies and the magnetic resonance imaging (MRI), and studied the dynamics behind hanging by applying an apparatus to cadaver and creating a dummy. MRI revealed that the vertebral artery protrudes diagonally upward from the second vertebra to the first one. We also found that this area was not covered with any bony tissue. The average length between the first and second transverse processes was 2 cm. We measured the minimum required force to obstruct the blood stream in both carotid and vertebral arteries exerting 130 mmHg. The required force was 6 kg for the carotid artery and 7 kg for the vertebral artery. Compared to the reported cases, there was not a significant difference in the force to obstruct the carotid artery, however, that of the vertebral artery was lower than the force reported so far. With an experiment of pressure sensitive plastic-sheet, we learned the lateral sides of the neck are compressed more. The results obtained from this study show that the complete and fatal obstruction of the carotid and the vertebral arteries may easily occur when the ligature transects at the lower part of mandible angle.
Legal Medicine | 2003
Katsuji Nishi; Akio Tanegashima; Yoshio Yamamoto; Ikuko Ushiyama; Keiko Ikemoto; Shigeru Yamasaki; Akiyoshi Nishimura; Steven Rand
We have investigated the deposition of glycoconjugates in human brain tissue with or without brain disorders. In this review we describe the application of lectin-histochemistry techniques to forensic neuropathology. Lectin staining is able to reveal several kinds of carbohydrate-related depositions in addition to the conventional degenerative changes including senile plaques, neurofibrillary tangles and corpora amylacea. The senile plaques and neurofibrillary tangles were clearly stained by Con A, PSA and GSI lectins, the corpora amylacea which is relevant to repeated brain hypoxia and mitochondrial damage was also easily detected by these and many other kinds of lectins. Amorphous spaces were detected around blood vessels and independently from blood vessels by lectin staining in the white matter from patients with brain disorders or severe edema. The white matter lesions were not considered relevant for forensic pathology, until a large group of cerebral white matter lesions were detected in the elderly with increasing frequency by modern neuro-imaging methods. The spherical deposits were newly detected by lectin staining in the molecular layer of the dentate gyrus of the hippocampal formation chiefly from patients with schizophrenia or cognitive dysfunctions.
Forensic Science Medicine and Pathology | 2007
Shigeru Yamasaki; Aki Kobayashi; Katsuji Nishi
Most evaluations of the pathophysiological processes of suicidal hangings are based on animal experiments and only a few have examined the hanging process. The little information available is mostly the result of animal experiments that have focused on tracheal obstructions. In the study presented here, a camcorder was set up by the victim to record the entire hanging process. According to the analysis from the recording, the complete asphyxial process lasted only 2 minutes and 43 seconds. Stage 1 (the prodromal stage) was especially short. Typical convulsions were not observed in this case. Body movements, such as clonic and tonic spasms, were not noticed in stage 2 (the dyspnea stage). Because the body did not touch the ground, the pressure on the neck by the ligature caused cerebral ischemia as a result of the obstruction of the neck vessels. Consequently, it can be hypothesized that sui cide by hanging may not be based on the effect of changed concentration in the blood of carbon dioxide and oxygen, but on the effect of cerebral ischemia.
Journal of Forensic Research | 2012
Satoshi Furukawa; Lisa Wingenfeld; Ikuo Sakaguchi; Tokiko Nakagawa; Akari Takaya; Satomu Morita; Shigeru Yamasaki; Katsuji Nishi
Transomental openings are usually congenital. Transomental hernia is a rare cause of intestinal obstruction. A 36-year-old female was found to have a transomental hernia at autopsy. We report the case of the strangulated intestinal obstruction with no past history.
Romanian Journal of Legal Medicine | 2012
Satoshi Furukawa; Lisa Wingenfeld; Ikuo Sakaguchi; Tokiko Nakagawa; Akari Takaya; Satomu Morita; Shigeru Yamasaki; Katsuji Nishi
Anil Aggrawal's Internet Journal of Forensic Medicine and Toxicology | 2005
Katsuji Nishi; Steven Rand; Tokiko Nakagawa; Aiko Yamamoto; Shigeru Yamasaki; Yoshio Yamamoto; Aki Kobayashi; Masateru Kane; Akira Morimoto; Hedwege Spalthoff; Beate Annuss
Forensic Science Medicine and Pathology | 2007
A. Takamure; Tokiko Nakagawa; Aki Kobayashi; S. Morimoto; Shigeru Yamasaki; Izumi Takase; Yusuke Yamamoto; Katsuji Nishi
Journal of Forensic Medicine | 2013
Satoshi Furukawa; Lisa Wingenfeld; Ikuo Sakaguchi; Tokiko Nakagawa; Akari Takaya; Satomu Morita; Shigeru Yamasaki; Katsuji Nishi
The Internet Journal of Forensic Science | 2012
Shigeru Yamasaki; Satoshi Furukawa; Lisa Wingenfeld; Akari Takaya; Tokiko Nakagawa; Ikuo Sakaguchi; Yoshio Yamamoto; Katsuji Nishi
The Internet Journal of Cardiology | 2012
Satoshi Furukawa; Lisa Wingenfeld; Ikuo Sakaguchi; Tokiko Nakagawa; Akari Takaya; Satomu Morita; Shigeru Yamasaki; Katsuji Nishi