|Budget Amount *help
¥3,770,000 (Direct Cost: ¥2,900,000、Indirect Cost: ¥870,000)
Fiscal Year 2012: ¥910,000 (Direct Cost: ¥700,000、Indirect Cost: ¥210,000)
Fiscal Year 2011: ¥2,860,000 (Direct Cost: ¥2,200,000、Indirect Cost: ¥660,000)
<Introduction> Microwave occurs when Improvised Explosive Devices was exploded. However, the effect for brain by Microwave has not been clarified.<Objectives> To analyze pathophysiology of brain injury induced by head-focused microwave irradiation in rats.<Materials and Methods> Under general anesthesia, S-D rats were irradiated by head-focused microwave by Microwave fixation system (Model MMW-05/ Muromachi Kikai Co., Ltd.), which were classified in three groups (3.2Kw/ 0.1sec (I), 2.6Kw/ 0.1sec (II),2.0Kw/ 0.1sec (III), and sham group) by intensity (n=3 in each group). Vital signs were evaluated, Arterial blood gas was examined, and we checked pathologic findings by Hematoxylin-Eosin (HE) stain immediately after Microwave irradiation, post 3 hours, 6 hours, 24 hours, 72 hours, 1 weeks, and 2 weeks in each group.<Results> Blood pressure was elevated transiently immediately after irradiation, and recovered in short period. PaO2 was unchanged in post-irradiation phase, except in Group I. In HE stain, Neuron was degenerated and left out especially in cerebral cortex and hippocampus, microglia cells were accumulated in these regions. These pathological changes were observed frequently and earlier, when irradiation was intense.<Discussion> The result was firstly reported that head-focused microwave irradiation induced brain injury in S-D rats, and this brain injury was related with intensity ofmicrowave. Pathological change was impressive because it was occurred gradually and progressive. Further study will be required, whether this type of brain injury is similarwith traumatic brain injury, or cerebral ischemia or not, and the study of behavioral effects of microwave irradiation is necessary, especially when the intensity of irradiation was not severe.