Department of Legal Medicine, Osaka City University Graduate School of Medicine

Main Research

The research conducted in our department is important in establishing more objective and accurate diagnostic techniques of death and disabilities which are in accordance with actual practices and in collecting and analysing data which contribute to evaluation and explanation of autopsy findings.

Previously, our department conducted practical research which is applicable to overall legal medicine with our main focus on two topics:

  • Morphological and molecular-biological study of the central nervous system and endocrine system organs, a comprehensive examination of objective evaluation of stress diagnosis
  • Physiobiochemical tests for evidence-based objective forensic-pathological diagnosis


I. Multilateral statistical analysis of forensic autopsy data

Outline: Forensic autopsies are performed to elucidate the cause and process of death and underlying diseases and/or complications associated with cases of ‘suspicious deaths’, including deaths by external causes and sudden deaths, which present potential social and legal issues. In many cases, there is limited information available on the medical history and the condition of death, yet an objective evaluation is required regardless.

Traditionally, diagnoses were heavily dependent on morphological findings; however, we, have actively applied various biomarkers used for clinical diagnosis to autopsy diagnosis. Furthermore, we have performed molecular-biological analysis of the process of death due to various causes to improve the accuracy of diagnosis.

As a result, important data on injury and illness prevention, as well as management of social crisis, are being accumulated through forensic diagnosis of individual cases. By statistically analysing and publishing these autopsy data, we can provide useful information for (1) improvement of the accuracy of forensic diagnosis, (2) prevention of injury and illness and (3) prevention of crimes and disasters. The course of data analysis is reflected in the results of appraisal for autopsies performed in our department.

II. Pathological analysis of death using postmortem computed tomography image data from forensic autopsies

Outline: Post-mortem cross-sectional imaging, which is useful in understanding the location and positional relationship of lesions, is used for screening before autopsy. Reconstructed images prepared based on examination data can also be used to explain injuries and diseases as appraisal documents for criminal and civil cases.

Specifically, a notable advantage of post-mortem computed tomography (CT) is that conditions of various organs within the body cavity can be observed in detail prior to the autopsy. These data can be used to examine the volume of various organs, estimated weight, and even distributions of CT values.

Here we use various indicators—estimated volume of the heart, lungs, and brain; pneumatization volume and rate of the lungs; and flattening rate of large blood vessels—obtained from post-mortem CT data from autopsy cases to analyze the respiratory and circulation pathologies at the time of death and quantitatively evaluate the extent of brain edema and other conditions.

Morphometric analysis of the heart, lungs, brain, and large vessels in the chest and abdomen using post-mortem CT data is useful in pathological analysis, such as evaluating the function of the heart, lungs, and central nervous system, by combining this data with the autopsy findings.

III. The role of vasopressin in the progression of brain oedema and application to severity evaluation

The pathophysiology of brain oedema which occurs due to various events such as cerebrovascular disorders, head trauma, breathing disorders, various poisoning, and metabolic disorder. This information can be used to understand the role of vasopressin in the progression of brain oedema and in severity evaluation.

It is becoming clear that vasopressin, which is a hormone which controls diuresis, is involved in nerve cell protection. To clarify the significance of vasopressin in forensic diagnosis, we use immunohistological and biochemical methods to examine changes in vasopressin in the brain.

Furthermore, we examine the changes in vasopressin concentration in blood and cerebrospinal fluid while comparing with morphological changes, and examine the role of vasopressin in the progression of brain oedema and evaluation of brain oedema severity.

IV. Risk evaluation of drug poisoning deaths based on individual genetic factors

Since specific pathological findings are limited in poisoning deaths, their diagnosis is strongly dependent on toxicological test results. However, definitive toxicological findings may not be obtained for drug abusers or in cases of protracted deaths. Even within treatment doses, deaths could occur as a side effect, making the determination of cause of death difficult.

In our department, we have routinely performed pathological, toxicological, and biochemical examinations in all autopsy cases, and have referenced and analysed pathological findings and biochemical data from drug poisoning such as from alcohol, stimulants, and psychotropic drugs.

As a result, systematic biochemical examinations have clarified parts of the clinical picture of drug poisoning and related deaths. In other words, the difference between systemic failure in ‘functional deaths’ such as rhabdomyolysis, death with various external causes such as heatstroke and freezing to death, and the process of sudden deaths have become clearer.

However, pathological and biochemical examinations are insufficient in understanding internal factors of each drug addicted person. Therefore, we analysed pharmacokinetics related genes in cases of drug poisoning deaths, and examined the establishment of cause of deaths and pathophysiology in cases of drug-related deaths from the genetic perspective.

V. Significance of pancreatic capsule and interstitial haemorrhage in forensic autopsies and behaviour of pancreas-related hormones

Is to examine the ‘significance of pancreatic capsule and interstitial haemorrhage in forensic autopsies and behaviour of pancreas-related hormones’. In forensic autopsies, interstitial haemorrhage may be noted without visual observation of actual pancreatic injury.

Therefore, we chose to study the significance of pancreatic capsule and interstitial haemorrhage from the perspective of hypoxia-ischemia, focusing on the association with exocrine and endocrine hormones.

Results of this research are not only significant in diagnosing death by suffocation in the field of legal medicine, but also would provide fundamental information in pancreas pathophysiology under low oxygen and ischemic conditions.

VI. Questionnaire for mental and psychological support to surviving families of crime and accident victims

Outline: Forensic autopsy with the main objective of public interest and public welfare require a great amount of respect and consideration toward the deceased and their family. Mental and psychological supports for surviving families of crime and accident victims are presently a major social issue.

In order to collect data, which are applicable to the present application, to determine measures to provide such support, we perform anonymous questionnaire on mental and psychological state as well as living conditions of surviving families after the death of a victim.