Cerebrospinal fluid aβ to tau ratio and postoperative cognitive change.

Objective: Determination of biomarker and neuropathogenesis of postoperative cognitive change (POCC) or postoperative cognitive dysfunction.

Background: POCC is one of the most common postoperative complications in elderly patients. Whether preoperative cerebrospinal fluid (CSF) β-amyloid protein (Aβ) to tau ratio, an Alzheimer disease biomarker, is a biomarker for risk of POCC remains unknown.

Impaired acquisition of spatial memory 2 weeks after isoflurane and isoflurane-nitrous oxide anesthesia in aged rats.

Aged rats are impaired on a spatial memory task for at least 24-48 h after isoflurane-nitrous oxide anesthesia. In this study, we tested how long the impairment lasts and investigated the role of nitrous oxide. Eighteen-month-old rats were randomized to anesthesia for 2 h with 1.