Dong-Ri Li

Postmortem biochemistry and immunohistochemistry of adrenocorticotropic hormone with special regard to fatal hypothermia

Adrenocorticotropic hormone (ACTH) is involved in systemic reactions to stress. The aim of the present study was a comprehensive analysis of serum and cerebrospinal fluid (CSF) levels of ACTH, and the pituitary immunohistochemistry with special regard to fatal hypothermia in routine forensic autopsy cases (n=162: 5-97 years of age; 114 males and 48 females; 4 h to 3 days postmortem, median, 19.2 h). The ACTH concentrations were independent of the postmortem time, gender, or age of the subjects. The serum ACTH level was similar to the clinical reference value for sharp instrument injury, fire fatality, and hypothermia, but was lower in other groups including hyperthermia, in particular for asphyxia and poisoning. The CSF level was usually much higher than the serum level, but was significantly lower for hypothermia and hyperthermia than in other groups (p<0.01). The rate of ACTH-immunopositivity in the anterior pituitary was low in cases of fatal hypothermia and hyperthermia, while it was high in cases of blunt injury, fire fatality, and acute ischemic heart disease. These observations showed that ACTH levels in the serum and CSF depended on the cause of death. The serum level was maintained despite a low CSF level and pituitary immunopositivity for fatal hypothermia, while the serum and CSF levels as well as pituitary immunopositivity were decreased for hyperthermia.

Tissue-specific differences in mRNA quantification of glucose transporter 1 and vascular endothelial growth factor with special regard to death investigations of fatal injuries

Glucose transporter 1 (GLUT1) and vascular endothelial growth factor (VEGF) have been established as being responsible for cellular adaptation to oxygen deficiency in tissue ischemia and hypoxia mediated by hypoxia-inducible factor 1. We hypothesized that mRNA quantification of these factors in autopsy tissue specimens could have diagnostic significance for investigating the pathology of death, especially after injury. Various cases (total, n=119; less than 48h postmortem) were examined, including fatal blunt injury (n=71) and sharp instrument injury (n=18), as well as asphyxia (strangulation/hanging, n=12) and acute myocardial infarction/ischemia (n=18) as controls. Quantification of mRNA by TaqMan real-time RT-PCR and immunostaining were performed for GLUT1 and VEGF in lung, kidney, and skeletal muscle specimens. The postmortem interval showed no significant influence on the relative quantification of mRNA during the early postmortem period. Characteristic results were found in blunt injury cases: both GLUT1 and VEGF mRNAs decreased in the lung but increased in the skeletal muscle depending on survival time. In the kidney, subacute deaths showed higher GLUT1 mRNA levels compared with acute deaths from blunt injury, but no significant change was found for VEGF mRNA. Immunohistochemistry showed visually predominant GLUT1 immunoreactivity in the renal cortex for cases with a longer survival time, coincident with the results at the mRNA level. Tissue-specific differences in mRNA quantification of GLUT1 and VEGF shed light on tissue ischemia/hypoxia and subsequent tissue-dependent pathophysiological changes leading to death after injury.

Suicidal vehicle-assisted ligature strangulation resulting in complete decapitation: An autopsy report and a review of the literature

The victim (59-year-old male) used a long hemp rope tied between his neck and a cherry tree while attempting to drive his car away, resulting in complete decapitation. At autopsy, the decapitation wound of the head and the torso corresponded perfectly; a clear-cut severance plane was found at the bottom of the skull. In contrast to suicidal decapitation by hanging and traumatic railway injury, autopsy findings for vehicle-assisted ligature strangulation are rarely reported. A review of the literature concerning suicidal vehicle-assisted ligature strangulation suggested a striking young or adult male predominance, and the wound margins were usually clear-cut with a sharply-demarcated encircling abrasion zone. The present case presented some notable autopsy findings involving wound morphology and pathological changes in organs related to the mechanisms of injury and death. Despite complete decapitation, the face was congestive, the lungs were congested with findings of acute respiratory distress, and the brain was markedly swollen with diffuse and severe astrocyte injury, suggesting that asphyxiation was involved in the death before decapitation.

Evaluation of postmortem S100B levels in the cerebrospinal fluid with regard to the cause of death in medicolegal autopsy

Previous studies have suggested the usefulness of the postmortem serum S100B level as a marker of the severity of brain damage. In this study, we investigated the S100B level in the cerebrospinal fluid (CSF) in serial autopsy cases (n=216, within 3 days postmortem), including those of blunt injury (n=34: fatal head injury, n=20; others, n=14), sharp instrument injury (n=9), mechanical asphyxiation (n=19), drowning (n=11), fire fatality (n=26), intoxication (n=20), hypothermia (cold exposure, n=16), hyperthermia (heat stroke, n=9), acute cardiac death (n=52) and pneumonia (n=20). The CSF S100B level showed a moderate postmortem time-dependent increase for acute cardiac death (r=0.58, p<0.0001) and asphyxia (r=0.741, p<0.001). In cases of survival time within 48 h, drowning and hypothermia usually showed a lower CSF S100B level (around 500 ng/ml), and the level was higher for delayed head injury death, asphyxia, intoxication, and hyperthermia (around 1500 ng/ml) (p<0.05). In fatal head injury cases, however, CSF S100B did not correlate with the survival time or postmortem interval. A CSF S100B level of >2000 ng/ml in the early postmortem period might be considered a biochemical sign of fatally severe brain damage.

Epstein–Barr virus myocarditis as a cause of sudden death: two autopsy cases

Although the Epstein–Barr virus (EBV) causes acute infection accompanied by a high fever in young people, there appears to be few reports of a fatal outcome involving myocarditis. We report two cases of unexpected sudden death due to acute myocarditis possibly caused by the EBV. They each visited a hospital due to common cold-like symptoms and unexpectedly died several days later. In both cases, autopsy revealed myocardial necrosis with marked lymphocytic infiltration. Polymerase chain reaction (PCR) screening was positive for the EBV, whereas immunohistochemistry and in situ hybridization for the EBV were negative. Serological investigations showed a mild elevation in antiviral capsid antigen IgG and anti-EBV nuclear antigen IgG in both cases. Immunohistochemical study of lymphocytic infiltrates showed strong positivity for a T-cell marker (CD45R0) in the myocardium and pharyngeal mucosa. These cases suggest the potential risk of mortality from acute EBV infection in young people, even without severe clinical manifestations, and the importance of microbiological investigations, including PCR procedures, in postmortem diagnosis of infectious diseases.

Quantitative analysis of GFAP- and S100 protein-immunopositive astrocytes to investigate the severity of traumatic brain injury

Previous studies have shown that diffuse cortical astrocyte damage is seen in acute deaths due to brain injury and mechanical asphyxiation. The present study quantitatively investigated the number of astrocytes that showed GFAP- and S100-protein immunopositivity in the cerebral white matter and hippocampus at the sites distant from primary injury with regard to survival time, complication, and the immediate cause of death of brain injury cases. Autopsy cases of brain injury (8-48 h postmortem) comprising acute/subacute deaths (survival time, <3/6 h-3 days; n=27/42) and delayed deaths (survival time >3 days) with/without complications (n=30/22) were examined. Delayed death cases with complications were subdivided into those in which the immediate cause of death had been determined as cerebral dysfunction (n=22) and those that had been determined as due to fatal complications (n=8). For controls, natural deaths from pneumonias (n=12) and sudden cardiac deaths (n=27) were used. In brain injury cases, the numbers of astrocytes in the cerebral white matter and hippocampal CA4 region were significantly lower for subacute death and delayed death without complications (p<0.05-0.001). Delayed death with fatal complications showed a significant increase in the number of astrocytes (p<0.05). Among delayed death cases, the numbers of astrocytes were higher in the cases with fatal complications than in those without complications and with non-fatal complications, although the latter cases showed large variations in the numbers of these astrocytes. These findings suggest that critical brain injury causes acute death without evident astrocyte pathology and that subacute death is associated with progressive brain damage accompanied by an astrocyte loss. In delayed death cases, the numbers astrocytes might be closely related to the severity of posttraumatic brain injury. GFAP and S100-immunopositivity might be useful for elucidating the cause and process of deaths due to brain injury.

Single-stranded DNA as an immunohistochemical marker of neuronal damage in human brain: an analysis of autopsy material with regard to the cause of death.

Single-stranded DNA (ssDNA) is a marker of apoptosis and programmed cell death, which appears prior to DNA fragmentation during delayed neuronal death. The present study investigated the immunohistochemical distribution of ssDNA in the brain to investigate apoptotic neuronal damage with regard to the cause of death in medicolegal autopsy cases (n=305). Neuronal immunopositivity for ssDNA was globally detected in the brain, independent of the age, gender of subjects and postmortem interval, and depended on the cause of death. Higher positivity was typically found in the pallidum for delayed brain injury death and fatal carbon monoxide intoxication, and in the cerebral cortex, pallidum and substantia nigra for drug intoxication. For mechanical asphyxiation, a high positivity was detected in the cerebral cortex and pallidum, while the positivity was low in the substantia nigra. The neuronal ssDNA increased during the survival period within about 24h at each site, depending on the type of brain injury, and in the substantia nigra for other blunt injuries. The neuronal positivity was usually lower for drowning and acute ischemic disease. Topographical analysis of ssDNA-positive neurons may contribute to investigating the cause of brain damage and survival period after a fatal insult.

Evaluation of postmortem calcium and magnesium levels in the pericardial fluid with regard to the cause of death in medicolegal autopsy.

Previous studies have suggested the usefulness of postmortem serum calcium (Ca) and magnesium (Mg) for investigating cause of death. The present study investigated their levels in the pericardial fluid of serial autopsy cases of adults within 48 h postmortem (n=385), including fatalities from blunt injury (n=57), sharp instrument injury (n=9), mechanical asphyxiation (n=28), salt- and freshwater drowning (n=14 and n=61, respectively), fire fatality (n=35), intoxication (n=23), hypothermia (cold exposure, n=12), hyperthermia (heat stroke, n=7), acute cardiac death (ACD, n=86), pneumonia (n=9) and spontaneous cerebral hemorrhage (n=11). The pericardial Ca level was independent of the postmortem interval, showing a value similar to that of the clinical reference range in cases other than saltwater drowning, while the Mg level was higher than the clinical reference range and showed a mild postmortem time-dependent increase. Pericardial Ca was significantly higher for saltwater drowning than other groups, and a lower level was seen for hyperthermia, and some cases of blunt injury and intoxication. The Mg level was also significantly higher for saltwater drowning than the other groups, and showed a higher level for sharp instrument injury, but a lower level for hypothermia. The Mg/Ca ratio was higher for sharp instrument injury and saltwater drowning, but was lower for hypothermia. These findings suggest that postmortem pericardial Ca and Mg can be used to investigate the cause of death, especially for saltwater drowning, hypothermia and hyperthermia.

Cardiothoracic ratio in postmortem chest radiography with regard to the cause of death

It is difficult to examine the intact in situ status of thoracic organs, including the heart and lungs, after opening the chest at autopsy. The present study investigated the pathological diagnostic significance of the cardiothoracic ratio (CTR) with regard to heart and lung weight in postmortem plain chest radiography. The pathological diagnostic significance of the CTR in postmortem plain chest radiography using serial forensic autopsy cases of adults (>19 years of age, n=367, within 72 h postmortem) was retrospectively investigated. In natural deaths, CTR was larger for heart diseases, and was smaller for pulmonary infection and gastrointestinal bleeding, showing correlations to the heart weight except in cases of hemopericardium. In traumatic deaths, CTR was larger in cases of fire fatality and acute methamphetamine intoxication, and varied in cases of blunt injury, showing correlations to the heart weight. However, CTR was smaller for sharp instrument injury and drowning, independently of the heart weight. These findings suggest that postmortem CTR (median, 55.6%, measured using a mobile X-ray apparatus) primarily depends on the heart weight, but is substantially modified during the process of death: the CTR may be enlarged by cardiac dilatation due to terminal congestive heart failure, but may be reduced by inflated lungs in drowning or hypovolemia due to fatal hemorrhage. CTR showed a mild correlation to the right diaphragm level, which was also related to the cause of death, but was independent of the left diaphragm level. Plain chest radiographic findings may also be helpful in investigating the pathophysiology of death, and are to some extent comparable with clinical findings. This also suggests the potential usefulness of postmortem CT and MRI for analysis of terminal cardiac function.

Morphological analysis of astrocytes in the hippocampus in mechanical asphyxiation

The present study investigated the morphology of astrocytes in the hippocampus and serum S100B levels in cases of mechanical asphyxia due to neck compression (n=23: atypical hanging, n=7; ligature/manual strangulation, n=16) with regard to the classical autopsy findings, compared with those of other types of asphyxiation (n=9) and acute myocardial infarction/ischemia (AMI, n=20). The decrease in intact astrocyte number, as shown by S100 and GFAP-immunostaining, was larger for asphyxiation due to neck compression compared with that for other asphyxiation and AMI, showing a correlation with the increase in the serum S100B levels. The decrease in intact astrocyte number and increase in serum S100B were closely related to the severity of conjunctival petechial hemorrhage and fracture(s) of the hyoid bone and/or thyroid cartilage in asphyxia due to neck compression. These findings suggest that hippocampal astrocyte injury is caused by cerebral hypoxia accompanied by congestion, especially in mechanical asphyxia due to neck compression.