The expression of excitatory amino acid transporter 2 in traumatic brain injury

It is well recognized that glutamate is the major excitatory neurotransmitter, which is removed from the synaptic cleft by excitatory amino acid transporter 2 (EAAT2) located on the perisynaptic astrocytes and that neuronal death has been associated with an increased extracellular glutamate concentration. In this study, we have immunohistochemically demonstrated the expression of EAAT2 protein in the human brain after traumatic brain injury (TBI). The EAAT2 expression patterns can be divided into three types: continuous and highly extensive staining (E); continuous but sporadic staining (M); and sporadic pattern staining (S). In six of the nine short survival cases studied (1 h to 1 day), continuous and highly extensive staining for EAAT2 (E type) was observed in the ipsilateral cerebral cortex. On the other hand, we were able to demonstrate weak staining (S and M types) in 5 of the 7 long survival cases (≥1 day) and in 12 of the 14 very short survival cases (<1 h) studied. Similar findings were obtained in the contralateral cerebral cortex and also in the ipsilateral hippocampus. In addition, positive staining for glial fibrillary acidic protein was detected around the cerebral contusion, but the EAAT2-positive expression was not observed in the same region for all of the six short and long survival cases (≥1 h) after TBI. These findings clearly showed the differences in EAAT2 expression in the cerebral cortex according to the survival time and severity of cerebral contusion after TBI. Therefore, we emphasized that EAAT2 might play an important role in contributing to extracellular glutamate concentrations and secondary brain injury after TBI.     

Air bag injuries--a literature review in consideration of demands in forensic autopsies

Air bags have been implicated in saving lives and reducing morbidity associated with motor vehicle crashes since their introduction in the mid-1970s. However, there is increasing evidence showing that air bags can be a source of injury and even death in certain circumstances. As the number of air bag-equipped vehicles increases, air bag-related injuries have occurred more frequently. Thus, a greater awareness of air bag-related injuries is required in forensic autopsies. Here, we review thoroughly the literature concerning air bag-related injuries with special regard to their nature and causative mechanisms, and summarize air bag-related injuries observed in adults, children and infants.