No abstract

Accumulation of misfolded proteins in the endoplasmic reticulum triggers a cellular stress response called the unfolded protein response (UPR) that protects the cell against the toxic buildup of misfolded proteins. Previously, we reported that UPR activation is increased in Alzheimer's disease (AD) patients. How the UPR relates to the pathological hallmarks of AD is still elusive. In the present study, the involvement of UPR activation in neurofibrillary degeneration in AD was investigated. Immunoreactivity for the phosphorylated UPR activation markers pancreatic ER kinase (pPERK), eukaryotic initiation factor 2␣, and inositol-requiring enzyme 1␣ was observed in hippocampal neurons associated with granulovacuolar degeneration. The percentage of pPERK-immunoreactive neurons was increased in AD cases compared with nondemented control cases and with the Braak stage for neurofibrillary changes. Although absent from neurofibrillary tangles, pPERK immunoreactivity was most abundant in neurons with diffuse localization of phosphorylated tau protein. Additional analyses showed that pPERK immunoreactivity was associated with ubiquitin and the ubiquitin binding protein p62. A strong co-occurrence of immunoreactivity for both pPERK and glycogen synthase kinase 3␤ in neurons was also observed. Together, these data indicate that UPR activation in AD neurons occurs at an early stage of neurofibrillary degeneration and suggest that the prolonged activation of the UPR is involved in both tau phosphorylation and neurodegeneration in AD pathogenesis. (Am J Pathol 2009,

OBJECTIVES:To study the effectiveness of haloperidol prophylaxis on incidence, severity, and duration of postoperative delirium in elderly hip-surgery patients at risk for delirium. DESIGN: Randomized, double-blind, placebo-controlled trial. SETTING: Large medical school-affiliated general hospital in Alkmaar, the Netherlands. PARTICIPANTS: A total of 430 hip-surgery patients aged 70 and older at risk for postoperative delirium. INTERVENTION: Haloperidol 1.5 mg/d or placebo was started preoperatively and continued for up to 3 days postoperatively. Proactive geriatric consultation was provided for all randomized patients. MEASUREMENTS: The primary outcome was the incidence of postoperative delirium (Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition, and Confusion Assessment Method criteria). Secondary outcomes were the severity of delirium (Delirium Rating Scale, revised version-98 (DRS-R-98)), the duration of delirium, and the length of hospital stay. RESULTS: The overall incidence of postoperative delirium was 15.8%. The percentage of patients with postoperative delirium in the haloperidol and placebo treatment condition was 15.1% and 16.5%, respectively (relative risk 5 0.91, 95% confidence interval (CI) 5 0.6-1.3); the mean highest DRS-R-98 score AE standard deviation was 14.4 AE 3.4 and 18.4 AE 4.3, respectively (mean difference 4.0, 95% CI 5 2.0-5.8; Po.001); delirium duration was 5.4 versus 11.8 days, respectively (mean difference 6.4 days, 95% CI 5 4.0-8.0; Po.001); and the mean number of days in the hospital was 17.1 AE 11.1 and 22.6 AE 16.7, respectively (mean difference 5.5 days, 95% CI 5 1.4-2.3; Po.001). No haloperidol-related side effects were noted. CONCLUSION: Low-dose haloperidol prophylactic treatment demonstrated no efficacy in reducing the incidence of postoperative delirium. It did have a positive effect on the severity and duration of delirium. Moreover, haloperidol reduced the number of days patients stayed in the hospital, and the therapy was well tolerated.