Acetylcholine affects the spatial scale of attention: evidence from Alzheimer's disease.

Location precues were used to manipulate the spatial scale of attention in visual search for a target in an array of letters in patients with dementia of the Alzheimer type (DAT) and in age-matched older controls. Cue size varied in the amount of spatial precision conferred. Scopolamine, a muscarinic antagonist, decreased overall arousal and broadened spatial attention after a precise precue (small and valid) to target location for DAT patients but not for controls, suggesting a selective effect for attentional impairment induced by cholinergic blockade.

Quantitative assessment of apolipoprotein E genotypes by image analysis of PCR-RFLP fragments.

Apolipoprotein E (APOE) genotyping usually involves polymerase chain reaction (PCR) and assessment of restriction fragment length polymorphism (RFLP) by gel electrophoresis. We made determination of HhaI restriction endonuclease digestive patterns more objective and improved diagnostic accuracy with a quantitative approach using sensitive DNA stain (SYBR Green) and image analysis of gel patterns. For distinguishing true and partially-digested restriction fragments, band ratios were calculated for the staining intensity of gel patterns from 116 sample runs of 63 human blood specimens.

Longitudinal stability of CSF tau levels in Alzheimer patients.

Background: Antemortem levels of tau in the cerebrospinal fluid (CSF) of Alzheimer's disease (AD) patients have repeatedly been demonstrated to be elevated when compared to controls. Although CSF tau has been reported to be elevated even in very mild AD, it is unknown how tau levels change during the course of the disease.

Methods: We have followed 29 mild-to-moderately affected AD subjects over 2 years with repeated CSF taps.

Physostigmine challenge before and after chronic cholinergic blockade in elderly volunteers.

Background: As a test of possible muscarinic up-regulation, the cortisol response to intravenous (i.v.) physostigmine (an anticholinesterase) was measured in 9 elderly volunteers before and after chronic cholinergic blockade with the muscarinic cholinergic antagonist scopolamine.

Discriminant power of combined cerebrospinal fluid tau protein and of the soluble interleukin-6 receptor complex in the diagnosis of Alzheimer's disease.

Alzheimer's disease (AD) still can only be definitively diagnosed with certainty by examination of brain tissue. There is a great need for a noninvasive, sensitive and specific in vivo test for AD. We combined cerebrospinal fluid analyses of tau protein (levels were significantly increased in AD patients [p=0.