Increased Expression of EMMPRIN and VEGF in the Rat Brain after Gamma Irradiation

The extracellular matrix metalloproteinase inducer (EMMPRIN) has been known to play a key regulatory role in pathological angiogenesis. A elevated activation of vascular endothelial growth factor (VEGF) following radiation injury has been shown to mediate blood-brain barrier (BBB) breakdown. However, the roles of EMMPRIN and VEGF in radiation-induced brain injury after gamma knife surgery (GKS) are not clearly understood. In this study, we investigated EMMPRIN changes in a rat model of radiation injury following GKS and examined potential associations between EMMPRIN and VEGF expression. Adult male rats were subjected to cerebral radiation injury by GKS under anesthesia. We found that EMMPRIN and VEGF expression were markedly upregulated in the target area at 8-12 weeks after GKS compared with the control group by western blot, immunohistochemistry, and RT-PCR analysis. Immunofluorescent double staining demonstrated that EMMPRIN signals colocalized with caspase-3 and VEGF-positive cells. Our data also demonstrated that increased EMMPRIN expression was correlated with increased VEGF levels in a temporal manner. This is the first study to show that EMMPRIN and VEGF may play a role in radiation injuries of the central nervous system after GKS.

Isolated intracranial Rosai Dorfman disease masquerading as meningioma: a case report.

Isolated intracranial Rosai Dorfman disease (sinus histiocytosis with massive lymphadenopathy) is rare. We present a 26-year-old male who presented with left focal motor seizures becoming secondarily generalized of one-year duration. Clinically and radiologically patient was diagnosed to have a right parietal convexity meningioma. However on histopathological examination a final diagnosis of intracranial Rosai Dorfman disease was rendered.