The role of computed tomography and magnetic resonance imaging in diagnosing clear cell ameloblastoma: A case report.

Ameloblastoma is the most common and clinically relevant type of odontogenic tumor. Clear cell odontogenic carcinoma is histologically characterized by solid sheets and nests of clear cells, whereas clear cell ameloblastoma (CCAM) is histologically characterized by an ameloblastomatous component intermixed with an extensive clear cell component. A total of 12 reports have been published on the histological etiology for CCAM; however, no reports have made regarding the detailed computed tomography and/or magnetic resonance imaging features of tumors of this type. The present study describes a case of a well-circumscribed 20-mm radiolucent lesion of the anterior mandible that was misdiagnosed as a clear cell odontogenic carcinoma. The study describes the detailed radiological characteristics of a case of CCAM.

Ketamine reduces amyloid ß-protein degradation by suppressing neprilysin expression in primary cultured astrocytes.

Pathological accumulation of cortical amyloid ß-protein (Aß) is an early and consistent feature of Alzheimer's disease (AD). Aß levels in the brain are determined by production and catabolism. Previous studies have suggested that deficits in the brain expression of neprilysin (NEP) and the insulin-degrading enzyme (IDE), which are both proteases involved in amyloid degradation, may promote Aß deposition in patients with sporadic late-onset AD. Because the incidence of AD increases after surgical intervention, we examined whether ketamine, which is a general anaesthetic with neuroprotective properties for excitotoxic ischaemic damage, is associated with Aß degradation by inducing NEP and IDE expression. The non-competitive N-methyl-d-aspartate receptor antagonist ketamine and MK801 significantly decreased the expression of NEP, but not IDE, in a concentration- and time-dependent manner through the dephosphorylation of p38 mitogen-activated protein kinase (MAPK) in cultured rat astrocytes. Furthermore, NEP-reduced reagents significantly suppressed the degradation of exogenous Aß in cultured astrocytes. These results suggested that ketamine suppresses the Aß degradation of NEP by reducing p38 MAPK-mediated pathway activity.