RESUMO
Early brain injury (EBI) is a series of pathophysiological changes occurring within 72 h after subarachnoid hemorrhage (SAH) and before cerebral vasospasm, which is a key factor affecting the outcome of SAH. The possible pathological mechanisms include cell metabolism, oxidative stress and immune inflammation, in which inflammatory response plays an important role. As the important immune cells in the central nervous system, microglia undergo M1/M2 polarization after brain injury. On the one hand, microglia secrete proinflammatory cytokines through Toll-like receptor 4 (TLR4), calcium sensing receptor (CaSR) and triggering receptor expressed on myoid cells 1 (TREM-1) mediated signaling pathways, which are involved in neuronal apoptosis, blood-brain barrier damage and brain edema after SAH. On the other hand, microglia play the anti-inflammatory and protective effects through the expression of neuroglobin and heme oxygenase 1. This article reviews the M1/M2 polarization process of microglia in EBI after SAH and its dual mechanisms of action.
RESUMO
Objective:To study the clinical and histological features of multiple meningiomas. Methods:39 cases of multiple meningiomas were analyzed retrospectively. The expressions of PR (Progesterone receptor) , p53 and MIB-1 were detected by immunohistochemistry in the samples of multiple meningiomas and solitary meningiomas. Results:Female predominance was obvious in cases of multiple meningiomas. The tumors had wide distributions with a main location in brain convexity. The results of immunohistochemistry showed stronger expression of PR and similar expression of p53 and MIB-1 in samples of multiple meningiomas than those in solitary meningiomas. Conclusion:The diagnosis of multiple meningiomas mainly depends on radiological examination. The pathogenesis of multiple meningiomas is probably related to progesterone and its receptor, and it is most likely monoclonal origin.