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09: Research Report: Forensic Medicine

What is Forensic medicine?
Upon hearing the word “forensic medicine”, what do you imagine? It is not a field of study that is familiar to the general public. Professor Youkichi Ohno has been devoting himself in this field and contributing a great deal to the welfare of the society. The medical group in Department of Legal Medicine at Nippon Medical School that he leads for more than 20 years consists of 10 staff members, a very big group for a forensic medicine department compared to any other departments in Japan.

Professor Ohno has been a very famous specialist in forensic medicine, because he conducted the administrative autopsy of the “aconite poisoning case” that happened in 1986 in Okinawa, when he was an associate professor of Department of Legal Medicine at Ryukyu University. The death of a young lady seemed to be caused by a heart attack, but it did not fully convince him and he thought that aconite was one of the possibilities. As aconite works as a cardiac poison with a very small amount, there was no method to test it at that time. Later, he asked some professional to develop an assay method to detect aconite in the biological samples so as to finally identify aconite as the real cause of the death. In 1992 he was welcomed as Professor of Department of Forensic Medicine at Nippon Medical School.

Then, what is “forensic medicine” anyway? What kind of academia is it? Professor Ohno described his department as follows: Forensic medicine is neither clinical medicine nor basic medicine; it is actually classified as social medicine. In other words, it is a field of medicine that solves sociological problems regarding law instead of individual problems of patients, thus the forensic professionals strive for fulfilling that purpose on a daily basis. Social problems regarding law are wide-ranging, but in the area of forensic medicine we cooperate to solve social problems that are more related to natural science and medicine and undertake necessary research. When there is damage on the body in some offence against the law, we can contribute to the society by examining the victim from the medical point of view. At the stage when the law is being enforced, medical judgment would be necessary even after people were dead. We are contributing to the society through practices such as forensic research and judicial autopsy.

Here, let us take a look at some of the activities of the Department of Forensic Medicine.

Researches done in Department of Forensic medicine

1. Acute Poisoning Analysis

Some causes of human being’s death are visually apparent but others are not. A case where a person died from poisoning belongs to the latter and needs meticulous forensic analysis to determine the real cause of death. Especially, some lethal substances can kill a person with only a very small amount, and so, it is imperative to set up analysis equipments to test for such a small amount of substances.

Professor Ohno told about the poisoning analysis system of his department. “One of the most important research themes of the department is the analysis of acute medication poisoning. Originally, we started to measure the blood alcohol concentration of patients by request from the advanced emergency center of Nippon Medical School, and then moved on to the extensive analysis and research on various poisonings.”

“In the late 90’s, poisoning cases due to potassium cyanide, arsenic, sodium azide and so on occurred so frequently in Japan. In response to increased social request for an extensive drug-testing regime, the country allocated national budget to testing facilities throughout Japan for equipping GC-MS (gas chromatograph-mass spectrometer), which is able to detect qualitatively and quantitatively a small amount of organic compounds, and made us cover a widespread area of analysis. And then, we have also introduced LC-MS (liquid chromatograph-MS) that allows us to analyze liquid samples. Thanks to all these equipments, our research level has reached a very high standard in Japan so that we have become a leader in this field.”

2. Research using NMR

Professor Ohno told about another research. “We have been also doing research using nuclear magnetic resonance (NMR) technique in the Department of Legal Medicine. Magnetic Resonance Imaging (MRI) in the clinical setting is a well-known application of NMR technique. Our research project includes identification of drugs and poisons, as well as analysis of antemortem metabolism and pathophysiology. NMR-based metabolic profiling may provide useful information that helps to estimate postmortem intervals and causes of death.”
“For example, we investigated metabolic changes after death in rat femoral muscles using pattern recognition of proton NMR spectra. All spectral data were processed and assessed by multivariate analysis to obtain metabolic profiles of the tissues. The results showed that the NMR-based metabolic profiling of tissues differed according to the mode of death and correlated with postmortem interval1) .”

Conclusion
Forensic medicine has been making progress over the years; however, on the other hand new medicinal toxicants are emerging one after another all over the world. The case is literally a cat and mouse game. As soon as the analysis of a particular toxicant is figured out, a very new strain of toxicants comes up. Indeed, there have been autopsies of the dead who died from illegal drugs and dangerous drugs. Under such circumstances, Professor Ohno has expressed his determination: “ As we are always facing new threats, we will strive to do forensic study and judicial autopsies to solve many sociological and political problems.”

1) Keiko Hirakawa, Kaoru Koike, Kyoko Uekusa, Makoto Nihira, Kohtaro Yuta, Youkichi Ohno. Experimental estimation of postmortem interval using multivariate analysis of proton NMR metabolomic data. Legal Medicine 11. 2009. S282–S285.

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Youkichi Ohno Department of Legal Medicine

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