Role of Rac1 GTPase in NADPH oxidase activation and cognitive impairment following cerebral ischemia in the rat.

Background: Recent work by our laboratory and others has implicated NADPH oxidase as having an important role in reactive oxygen species (ROS) generation and neuronal damage following cerebral ischemia, although the mechanisms controlling NADPH oxidase in the brain remain poorly understood. The purpose of the current study was to examine the regulatory and functional role of the Rho GTPase, Rac1 in NADPH oxidase activation, ROS generation and neuronal cell death/cognitive dysfunction following global cerebral ischemia in the male rat.

Methodology/principal Findings: Our studies revealed that NADPH oxidase activity and superoxide (O(2)(-)) production in the hippocampal CA1 region increased rapidly after cerebral ischemia to reach a peak at 3 h post-reperfusion, followed by a fall in levels by 24 h post-reperfusion.

Melanocytic differentiation in a solid pseudopapillary tumor of the pancreas.

Solid pseudopapillary tumor of the pancreas (SPT) is an uncommon neoplasm of low malignant potential, generally occurring in young women. The tumor is indolent, usually with long survival, even in the presence of extension into adjacent organs and metastases. Pathological features include solid, cellular, and cystic regions and degenerative pseudopapillae formation.