This study aimed to analyze how the ubiquitin proteasome system (UPS) or autophagy lysosome system (autophagy) are induced in brain tissues at different intervals after traumatic intracranial injury in humans. Injured cerebral cortices of 36 forensic autopsy cases were analyzed by immunohistochemistry using antibodies as the UPS marker (ubiquitin and lysine 48-linked polyubiquitin chains [K48]) and autophagy marker (lysine 63-linked polyubiquitin chains [K63], p62/sequestome 1 and microtubule-associated protein 1 light chain 3 [LC3]). The number of neurons and glial cells with cytoplasmic inclusions that stained positive for ubiquitin, K48, and p62 began to increase within 1 hour after intracranial injury, particularly at contusion sites. From 3.5 hours onward, an increase in cytoplasmic inclusions that stained positive for K63 and LC3 began to be detected. LC3-positive cytoplasmic inclusions were not identified after 37 days; however, the increased immunoreactivity to ubiquitin and anti-K48 antibody was maintained for 7 months. These results suggest that the UPS is activated earlier and lasts longer than autophagy, that autophagy is activated for a relatively short term (between a few hours and approximately 1 month), and that the activation occurs especially in severely damaged brain tissues following head trauma in humans.

Clasmatodendrosis is associated with UPS-mediated, autophagy and relatively acute pathological findings after traumatic intracranial injury.

A fall from a great height is often associated with altered mental status. Aside from the usual contributing factors, for example, alcohol consumption or mental illness, natural disease leading to a fatal fall is seldom identified by autopsy. The case described in this report is that of a 57-year-old man who had been clinically diagnosed with presenile Alzheimer disease and fell head first into a river from the bridge. These events were captured by a surveillance camera on the bridge; an acquaintance reported that he had previous suicidal ideation. At autopsy, the cervical spinal cord was determined to have been severely injured, and the sixth cervical vertebra was observed to have been fractured. Histological examination showed chronic meningoencephalitis including neuronal loss, perivascular cuffing, and the proliferation of microglia and astrocytes in the cerebral cortex. Serologic evaluation consisting of the nontreponemal antigen test (rapid plasma reagin [RPR]) and treponemal antibody test (Treponema pallidum latex agglutination) was positive in both cases (RPR: 18.2 RPR units, T. pallidum latex agglutination: 7718 U/mL). These findings suggested that the patient had been affected by a syphilis infection and that his suicidal behavior was associated with parenchymatous neurosyphilis.

Studies of four male victims who were killed in an accidental tunnel gas explosion on urban reclaimed land are described. The studies were judicial autopsy examinations to determine the precise causes of death. Two men died of carbon monoxide intoxication, one died of massive brain damage, and the fourth died of drowning. The concentrations of methane in several organs were much lower than the lethal level, whereas those in adipose tissue were relatively high. These findings indicated that a low concentration of methane was almost always present in the atmosphere at the construction site. Recently, coal mine accidents have been decreasing in Japan. However, there is still a possibility of underground explosions or gas leaks in confined spaces other than coal mines. To determine the precise cause of death in such cases, careful autopsies and other examinations should be performed using methods similar to those used in coal mine accidents.

No abstract