Obstructive sleep apnea decreases central nervous system-derived proteins in the cerebrospinal fluid.

We hypothesized that one mechanism underlying the association between obstructive sleep apnea (OSA) and Alzheimer's disease is OSA leading to decreased slow wave activity (SWA), increased synaptic activity, decreased glymphatic clearance, and increased amyloid-β. Polysomnography and lumbar puncture were performed in OSA and control groups. SWA negatively correlated with cerebrospinal fluid (CSF) amyloid-β-40 among controls and was decreased in the OSA group.

Recommendations for the Generation, Quantification, Storage, and Handling of Peptides Used for Mass Spectrometry-Based Assays.

Background: For many years, basic and clinical researchers have taken advantage of the analytical sensitivity and specificity afforded by mass spectrometry in the measurement of proteins. Clinical laboratories are now beginning to deploy these work flows as well. For assays that use proteolysis to generate peptides for protein quantification and characterization, synthetic stable isotope-labeled internal standard peptides are of central importance.

Neurogranin as a Cerebrospinal Fluid Biomarker for Synaptic Loss in Symptomatic Alzheimer Disease.

Importance: Neurogranin (NGRN) seems to be a promising novel cerebrospinal fluid (CSF) biomarker for synaptic loss; however, clinical, and especially longitudinal, data are sparse.

Objective: To examine the utility of NGRN, with repeated CSF sampling, for diagnosis, prognosis, and monitoring of Alzheimer disease (AD).

Design, Setting, And Participants: Longitudinal study of consecutive patients who underwent 2 lumbar punctures between the beginning of 1995 and the end of 2010 within the memory clinic-based Amsterdam Dementia Cohort.