Daisuke Miyamori
Kyoto Prefectural University of Medicine
Network
Latest external collaboration on country level. Dive into details by clicking on the dots.
Publication
Featured researches published by Daisuke Miyamori.
Toxicology | 2013
Takeshi Uemura; Yuka Tanaka; Kyohei Higashi; Daisuke Miyamori; Tomokazu Takasaka; Tatsuo Nagano; Toshihiko Toida; Kanji Yoshimoto; Kazuei Igarashi; Hiroshi Ikegaya
Ethanol consumption causes serious liver injury including cirrhosis and hepatocellular carcinoma. Ethanol is metabolized mainly in the liver to acetic acid through acetaldehyde. We investigated the effect of ethanol and acetaldehyde on polyamine metabolism since polyamines are essential factors for normal cellular functions. We found that acetaldehyde induced spermine oxidase (SMO) at the transcriptional level in HepG2 cells. The levels and activities of ornithine decarboxylase (ODC) and spermidine/spermine acetyltransferase (SSAT) were not affected by acetaldehyde. Spermidine content was increased and spermine content was decreased by acetaldehyde treatment. Knockdown of SMO expression using siRNA reduced acetaldehyde toxicity. Acetaldehyde exposure increased free acrolein levels. An increase of acrolein by acetaldehyde was SMO dependent. Our results indicate that cytotoxicity of acetaldehyde involves, at least in part, oxidation of spermine to spermidine by SMO, which is induced by acetaldehyde.
Journal of Biomedical Optics | 2015
Giuseppe Pezzotti; Marco Boffelli; Daisuke Miyamori; Takeshi Uemura; Yoshinori Marunaka; Wenliang Zhu; Hiroshi Ikegaya
Abstract. The possibility of examining soft tissues by Raman spectroscopy is challenged in an attempt to probe human age for the changes in biochemical composition of skin that accompany aging. We present a proof-of-concept report for explicating the biophysical links between vibrational characteristics and the specific compositional and chemical changes associated with aging. The actual existence of such links is then phenomenologically proved. In an attempt to foster the basics for a quantitative use of Raman spectroscopy in assessing aging from human skin samples, a precise spectral deconvolution is performed as a function of donors’ ages on five cadaveric samples, which emphasizes the physical significance and the morphological modifications of the Raman bands. The outputs suggest the presence of spectral markers for age identification from skin samples. Some of them appeared as authentic “biological clocks” for the apparent exactness with which they are related to age. Our spectroscopic approach yields clear compositional information of protein folding and crystallization of lipid structures, which can lead to a precise identification of age from infants to adults. Once statistically validated, these parameters might be used to link vibrational aspects at the molecular scale for practical forensic purposes.
Journal of Forensic and Legal Medicine | 2013
Noboru Ishikawa; Atsushi Nishida; Daisuke Miyamori; Toshikazu Kubo; Hiroshi Ikegaya
Computed tomography (CT) in forensic medicine is commonly used in determination of cause of death. Here, we show that the information provided by CT may also be of value for estimation of time after death. The relationship between abdominal aorta narrowing just below the diaphragm and time after death was examined in 140 cases. Aorta narrowing was defined using a flatness ratio, which was calculated by dividing the shorter axis of the aorta by the longer axis. Time after death was classified into 6 time periods. The flatness ratio gradually and significantly decreased with increased postmortem time, showing increased aorta narrowing with increased time after death. A further examination of aorta narrowing in 15 autopsy cases in which CT images were taken at two postmortem times gave similar findings. The results of the study suggest that aorta narrowing in postmortem CT imaging may be used to estimate time after death.
Journal of Forensic and Legal Medicine | 2013
Daisuke Miyamori; Noboru Ishikawa; Yoshihisa Akasaka; Kei Yamada; Hiroshi Ikegaya
BACKGROUNDnComputed Tomography (CT) is now utilized as an effective tool for postmortem diagnoses. However, reports on the temporal evolution in imaging findings of these postmortem CT is limited.nnnCASE PRESENTATIONnOne night, a 66 year old male following drinking at a bar on his way home slept in the road. He was ran over by a taxi at 01:28 and immediately transferred to a nearby hospital. During his transfer to the hospital, he lost consciousness and fell into a state of cardiopulmonary arrest, and died despite resuscitation attempts. CT images were taken at 02:30. Following this, CT images were re-taken 54 h after death, just prior to a medicolegal autopsy.nnnRESULT & DISCUSSIONnSmall amount of intra-abdominal hemorrhage was found during the initial CT examination. However, the extent of intra-abdominal bleeding observed during the second CT examination performed 54 h later had substantially increased. During the autopsy, the amount of intra-abdominal hemorrhage was 1700 mL. Injury to the mesentery, liver and pancreas was also observed. Additional major injuries discovered during the autopsy were, skin abrasions and lacerations of the scalp, subarachnoid hemorrhage, fractures of the ribs, right humerus, and pelvic bones. The deceased postmortem blood alcohol level was 2.4 mg/mL. The cause of death was determined as exanguination due to systemic injury. The mechanism of the postmortem increase in the intra-abdominal hemorrhage remained unknown. However, the amount of bleeding found during autopsies may not be the same as that at the time of death. As a result, the criteria for the diagnosis of the cause of death in autopsies should be carefully reconsidered. In addition, accompanying CT imaging at the time of death and possible postmortem changes should be carefully considered in postmortem CT imaging, so that there will not be incorrect assignment of the causes of death.
Science & Justice | 2016
Mayuko Nomura; Stuart McLean; Daisuke Miyamori; Yasuhiro Kakiuchi; Hiroshi Ikegaya
PURPOSEnJapanese society has reached an unprecedented level of aging, with elderly people accounting for 25.1% of the population in October 2013. These changes have created concerns regarding deaths among the elderly. In this study, we compared recent forensic autopsy cases with cases from about 20 years ago, with the goal of understanding the context of death among the elderly within Japanese society today.nnnMETHODSnWe investigated the forensic autopsy records of 297 people aged 65 years or above. In order to examine the effect of residential circumstances, we classified these cases into two groups: people who lived alone (group A) and those who lived with their family (group B). Forty-five of these autopsy cases were conducted about 20 years ago (1989 to 1993) and 252 cases were recent (2009 to 2013). The cases were limited to people who had been found dead or in a critical situation at home. We investigated the first finder, the period of time elapsed between death and discovery, and the cause of death.nnnRESULTSnThe incidence of the first finder being a family member was more than 20% greater in group B compared with group A. The proportions of cases for which it took more than three days for someone to find the body or an abnormal situation were about 14% and 7% in groups A and B, respectively, 20 years ago, and about 48% and 19% among the recent cases. These proportions were significantly higher among the recent cases. Among recent cases, a post-mortem elapsed time of more than 3 days occurred more often in group A than group B (p=0.0002). None of the older cases had an unknown cause of death in either group. However, among the recent cases from both groups, 20-30% of cases resulted in unknown causes of death. The incidences of unknown causes of death were significantly higher among the recent cases in both groups (p=0.015) and in group B alone (p=0.037). The incidences of murder cases were significantly lower in group B among the recent cases (p=0.0022).nnnDISCUSSIONnElderly people who live alone are not easily found or aided when in critical situations, and they may only be discovered after death. Prolongation of the postmortem interval (PMI) results in the deterioration of the corpse making determination of cause of death problematic. The results of this study suggest that there are three factors that isolate elderly people and increase the difficulty in determining their cause of death: reduced communication with family members, reduced communication with neighbors or the community, and the increasing prevalence of the nuclear family. In group B, the prolonged discovery time and the increased incidence of unknown causes of death suggest reduced communication with family members, even though the incidence of being found by a family member was higher than in group A. The murder rate was significantly lower in group B, which may suggest that cases of domestic murder were overlooked. Support for a safe life and peaceful ending for the elderly requires a system based on three factors: remote monitoring to ensure safety, the establishment of elderly groups providing mutual support, and increased visits from welfare workers. Understanding the circumstances of the elderly who die alone is beneficial to countries facing an aging society with weakened family or community structures, and who hope for better support for the elderly.
Legal Medicine | 2015
Nozomi Idota; Masaki Kobayashi; Daisuke Miyamori; Yasuhiro Kakiuchi; Hiroshi Ikegaya
Progestin/estrogen oral contraceptives have some side effects, including venous thromboembolism. To alleviate side effects, improvements have been made to low-dose oral contraceptives, including reductions in the amount of estrogen and/or changes the type of progestin. A compound drug containing 3mg drospirenone and 20μg ethinylestradiol (DRSP/EE20, YAZ®) was released in overseas markets in 2006, and in Japan in 2010 as a newly developed low-dose medicines. This drug is expected to have lower side effects. We received a medicolegal autopsy case of a young woman who had been prescribed YAZ for dysmenorrhea for 17months. The autopsy revealed a blood clot in her pulmonary artery bifurcation. Blood screening by ultra-performance liquid chromatography-mass spectrometry analysis did not detect any medicinal toxicants. However, from police investigations, it is strongly believed that she had been taking YAZ. Therefore we performed a single ion resolution mode assay and detected DRSP. A quantitative analysis revealed 32.3ng/mL of DRSP. As no other cause of the pulmonary thromboembolism was evident, we consider YAZ as the likely cause of the pulmonary thromboembolism. Recent reports from the past few years suggest a higher risk of venous thromboembolism with DRSP/EE20 than earlier progestin/estrogen oral contraceptives. Comparing the risk associated with DRSP/EE20 and DRSP/EE30, one report found no differences and another report showed DRSP/EE20 was associated with a higher risk than DRSP/EE30. No cases of thrombosis caused by progestin alone have been reported. But comparing the risk between DRSP/EE20 and other progestins/EE20, two studies reported DRSP/EE20 had a higher risk than other progestins/EE20. The incidence of venous thromboembolism is highest in the first year of use and decreases thereafter. Because DRSP/EE20 has been on the market for only a couple of years, it is necessary for clinicians to use the drug carefully and accumulate more side-effect data. It is important for forensic scientists to confirm all of the prescribed drugs in autopsy cases, search the risks of identified drugs, particularly new drugs, and provide relevant case information in a timely manner.
Journal of Forensic and Legal Medicine | 2015
Noboru Ishikawa; Hideki Suganami; Atsushi Nishida; Daisuke Miyamori; Yasuhiro Kakiuchi; Naotake Yamada; Kim Wook-Cheol; Toshikazu Kubo; Hiroshi Ikegaya
In the field of Forensic Medicine the number of unidentified cadavers has increased due to natural disasters and international terrorism. The age estimation is very important for identification of the victims. The degree of sagittal closure is one of such age estimation methods. However it is not widely accepted as a reliable method for age estimation. In this study, we have examined whether measuring impedance value (z-values) of the sagittal suture of the skull is related to the age in men and women and discussed the possibility to use bone impedance for age estimation. Bone impedance values increased with aging and decreased after the age of 64.5. Then we compared age estimation through the conventional visual method and the proposed bone impedance measurement technique. It is suggested that the bone impedance measuring technique may be of value to forensic science as a method of age estimation.
Investigative Genetics | 2015
Daisuke Miyamori; Noboru Ishikawa; Nozomi Idota; Yasuhiro Kakiuchi; Stuart McLean; Tadaichi Kitamura; Hiroshi Ikegaya
BackgroundAccording to the dual structure model, the modern Japanese ethnic population consists of a mixture of the Jomon people, who have existed in Japan since at least the New Stone Age, and the Yayoi people, who migrated to western Japan from China around the year 300u2009bc Some reports show that the Yayoi are linked to a mutation of the aldehyde dehydrogenase 2 gene (ALDH2).Recent viral studies indicate two major groups found in the Japanese population: a group with the CY genotype JC virus (JCV) and a group with the MY genotype JCV. It is unclear whether either genotype of the JC virus is related to the Jomon or Yayoi.In this study, we attempted to detect JCV genotypes and ALDH2 mutations from the DNA of 247 Japanese urine samples to clarify the relationship between the dual structure model and the JCV genotype through ALDH2 mutation analysis and JCV genotyping.FindingsThe ALDH2 polymorphism among 66 JC virus-positive samples was analyzed, and it was found that the ALDH2 variant is significantly higher in the population with CY genotype JCV (51.5xa0%) than in the population with the MY genotype (24.2xa0%) (pu2009<u20090.05).ConclusionFrom these findings, it may be inferred that the ALDH2 mutation, which is related to the Yayoi, is related to CY genotype JCV. When the Yayoi migrated to the Japanese archipelago, they brought the ALDH2 mutation as well as the CY genotype JCV.
Forensic Science International | 2012
Masaaki Sakabe; Daisuke Miyamori; Stuart McLean; Natsuko Shinmen; Hideaki Kato; Kanji Yoshimoto; Hiroshi Ikegaya
The use of moxibustion today does not only take place in Eastern Asia, but recently also in Europe and the United States. Moxibustion scars are often seen in autopsy cases in Japan. However, no reports of the use of moxibustion in autopsy cases have been reported. This paper reports on an autopsy case in which moxibustion scars were used to extrapolate on the past symptoms of the deceased, date of therapy and the location of the moxibustion clinic which administered the moxibustion.
Archive | 2016
Mayuko Nomura; Stuart McLean; Daisuke Miyamori; Yasuhiro Kakiuchi