{'fraction_non_alphanumeric': 0.05370843989769821, 'fraction_numerical': 0.024552429667519183, 'mean_word_length': 5.2492012779552715, 'pattern_counts': {'":': 0, '<': 3, '<?xml version=': 0, '>': 0, 'https://': 0, 'lorem ipsum': 0, 'www.': 0, 'xml': 0}, 'pii_count': 0, 'substrings_counts': 0, 'word_list_counts': {'cursed_substrings.json': 0, 'profanity_word_list.json': 0, 'sexual_word_list.json': 0, 'zh_pornsignals.json': 0}}
Distinct pools of beta-amyloid in Alzheimer disease-affected brain: a clinicopathologic study.

OBJECTIVE
To determine whether beta-amyloid (Abeta) peptides segregated into distinct biochemical compartments would differentially correlate with clinical severity of Alzheimer disease (AD).


DESIGN
Clinicopathologic correlation study.


PARTICIPANTS
Twenty-seven patients from a longitudinal study of AD and 13 age- and sex-matched controls without a known history of cognitive impairment or dementia were included in this study.


INTERVENTIONS
Temporal and cingulate neocortex were processed using a 4-step extraction, yielding biochemical fractions that are hypothesized to be enriched with proteins from distinct anatomical compartments: TRIS (extracellular soluble), Triton (intracellular soluble), sodium dodecyl sulfate (SDS) (membrane associated), and formic acid (extracellular insoluble). Levels of Abeta(40) and Abeta(42) were quantified in each biochemical compartment by enzyme-linked immunosorbent assay.


RESULTS
The Abeta(42) level in all biochemical compartments was significantly elevated in patients with AD vs controls (P < .01). The Abeta(40) levels in the TRIS and formic acid fractions were elevated in patients with AD (temporal, P < .01; cingulate, P = .03); however, Triton and SDS Abeta(40) levels were similar in patients with AD and in controls. Functional impairment proximal to death correlated with Triton Abeta(42) (r = 0.48, P = .02) and SDS Abeta(42) (r = 0.41, P = .04) in the temporal cortex. Faster cognitive decline was associated with elevated temporal SDS Abeta(42) levels (P < .001), whereas slower decline was associated with elevated cingulate formic acid Abeta(42) and SDS Abeta(42) levels (P = .02 and P = .01, respectively).


CONCLUSION
Intracellular and membrane-associated Abeta, especially Abeta(42) in the temporal neocortex, may be more closely related to AD symptoms than other measured Abeta species.