Cited by 676Alzheimer's disease research and treatmentsDementia and Cognitive Impairment ResearchNeuroinflammation and Neurodegeneration Mechanisms

The DOI matches its Crossref record; 20 of the 20 references it cites were found in a registry or an index; none of the 32 sources its claims cite is checked for support yet.

Amyloid β Protein (Aβ) in Alzheimeri's Disease Brain

Open access

Abstract

Biochemical and immunocytochemical analyses were performed to evaluate the composition of the amyloid beta protein (A beta) deposited in the brains of patients with Alzheimer's disease (AD). To quantitate all A beta s present, cerebral cortex was homogenized in 70% formic acid, and the supernatant was analyzed by sandwich enzyme-linked immunoabsorbent assays specific for various forms of A beta. In 9 of 27 AD brains examined, there was minimal congophilic angiopathy and virtually all A beta (96%) ended at A beta 42(43). The other 18 AD brains contained increasing amounts of A beta ending at A beta 40. From this set, 6 brains with substantial congophilic angiopathy were separately analyzed. In these brains, the amount of A beta ending at A beta 42(43) was much the same as in brains with minimal congophilic angiopathy, but a large amount of A beta ending at A beta 40 (76% of total A beta) was also present. Immunocytochemical analysis with monoclonal antibodies selective for A beta s ending at A beta 42(43) or A beta 40 confirmed that, in brains with minimal congophilic angiopathy, virtually all A beta is A beta ending at A beta 42(43) and showed that this A beta is deposited in senile plaques of all types. In the remaining AD brains, A beta 42(43) was deposited in a similar fashion in plaques, but, in addition, widely varying amounts of A beta ending at A beta 40 were deposited, primarily in blood vessel walls, where some A beta ending at A beta 42(43) was also present. These observations indicate that A beta s ending at A beta 42(43), which are a minor component of the A beta in human cerebrospinal fluid and plasma, are critically important in AD where they deposit selectively in plaques of all kinds.

Overview

AI snapshot

Written from the paper’s full text.

TL;DR

In Alzheimer’s disease (AD) brain, Aβ ending at Aβ42(43) is the predominant deposited species in cases with minimal congophilic angiopathy, while Aβ40 becomes prominent mainly in brains with substantial vascular amyloid. The authors conclude that Aβ42(43), though a minor secreted species, is critically important in AD because it deposits selectively in senile plaques of all types.

Key findings

  • In 9 of 27 AD brains with minimal congophilic angiopathy, virtually all Aβ (96%) ended at Aβ42(43); BC-05/4G8 detected 4663 ± 421 pmol/g versus BAN-50/BC-05 at 714 ± 68 pmol/g, while BA-27/4G8 detected only 216 ± 38 pmol/g.
  • In 6 AD brains with substantial congophilic angiopathy, Aβ42(43) amounts were similar to minimal-angiopathy brains (BC-05/4G8: 5089 ± 409 pmol/g; BAN-50/BC-05: 826 ± 119 pmol/g), but Aβ40 was dramatically increased (BA-27/4G8: 13,607 ± 3397 pmol/g; BAN-50/BA-27: 5001 ± 2164 pmol/g). The abstract reports 76% of total Aβ ended at Aβ40 in these brains; the Results state an average of 67%.
  • Total Aβ in 27 AD brains ranged from at least 500 to 4400 times that in plaque-free control brain; 98.5% of total Aβ required formic acid for solubilization and only 1.5% was extracted into Tris-saline.
  • Immunocytochemistry showed BC-05 and 4G8 intensely labeled all plaque types and vascular amyloid, whereas BA-27 stained vascular amyloid well but stained plaque cores less intensely and almost failed to stain uncored plaques.

Methods

  • AD and plaque-free control cerebral cortex was homogenized directly in 70% formic acid or sequentially extracted first into Tris-saline buffer with protease inhibitors and then into 70% formic acid.
  • Aβ was quantitated by sandwich ELISAs specific for forms ending at Aβ40 (BA-27/4G8 or BAN-50/BA-27) or Aβ42(43) (BC-05/4G8 or BAN-50/BC-05), with some samples fractionated by Superose 12 size exclusion chromatography.
  • Samples included an initial 3 AD and 3 control brains, then 27 AD and 6 plaque-free control brains; immunocytochemistry used formalin- or methacarn-fixed inferior temporal cortex with BA-27, BC-05, and 4G8 antibodies.

Limitations

  • The paper does not state a formal limitations section. The authors note that BAN-50 cannot capture Aβs beginning at or beyond Aβ17, so the increased Aβ detected with 4G8 may indicate considerable amino-terminally truncated Aβ, but they caution this interpretation because other factors such as isoaspartates at Aβ1 and Aβ37 may diminish BAN-50 capture.
  • The authors address the concern that BA-27 epitope destruction during fixation could distort immunocytochemistry, arguing against it because brains with minimal vascular amyloid had virtually all Aβ ending at Aβ42(43).
  • Evident from the text: subgroup analyses rely on small numbers (e.g., 9 minimal and 6 substantial congophilic angiopathy cases), and no formal statistical comparisons are reported.

Model-written summary. Check it against the paper before relying on it.

Integrity signals

Registry

Crossref · 10.1074/jbc.270.13.7013

Cites

20 of 20 references verified0 citation errors · 0 not checkable

Statistics

Nothing to recompute.

Verification

Claims the paper makes

0 of 32 cited sources checked · 0 supported · 0 flagged

Show all 36 claims

  • It may state two separate claims as one. 14
  • Probably not a substantial claim. 2
16 of 16
  • The paper relies on this without support.

    The recovery of synthetic Aβ added to control brain applies to endogenous Aβ in AD brain.

    “To assess Af3 recovery, synthetic Af3 (500 pmol of A{31-4o plus 500 pmol of Af31-42, Bachem) was added to samples of cerebral cortex (-0.5 g) from control brains prior to homogenization.”
1 of 1

Claims other papers make about this one

Each is checked against this paper’s own text: does it say what the citing paper says it does?

Self-check

Percentages, sums and reported differences re-computed from the paper’s own numbers.

Each contradiction between two passages listed here was confirmed by an independent check.

  • Conflicting percentages of Aβ ending at Aβ40

    Major

    For the six brains with substantial congophilic angiopathy, the abstract states that 76% of total Aβ ended at Aβ40, while the results state that the average was 67%. Both statements describe the same six-brain group.

1 of 1

Citations

Cites

Flagged first, then by citations

Show all 20 references

Research works printed but not linked: 4

  1. Masliah, 1990, Am. J. Pathol., 137, 1293
  2. Kim, 1988, Neurosci. Res. Commun., 2, 121
  3. Suzuki, 1994, Am. J. Pathol., 145, 452
  4. Iwatsubo, 1995, Ann. Neurol.

Cited by

Sorted by citations

Items 601–674 of 674

Metadata

Authors
Gravina, S. A., Ho, L., Eckman, C. B., Long, K. E., Otvos, L., Younkin, L. H., Suzuki, N., & Younkin, S. G.
Affiliations
  • Case Western Reserve University (US)
  • Takeda (Japan) (JP)
Corresponding author
Younkin, Steven G.
Venue
Journal of Biological Chemistry
Publisher
Elsevier BV
Published
1995-03
Volume
270
Issue
13
Pages
7013-7016
ISSN
0021-9258 (ISSN-L)
OpenAlex
W1618236677
Cited by
676
References
20
Citations by year
2026: 8 · 2025: 16 · 2024: 19 · 2023: 21 · 2022: 23 · 2021: 33 · 2020: 33 · 2019: 22 · 2018: 18 · 2017: 22 · 2016: 27 · 2015: 20 · 2014: 22 · 2013: 24 · 2012: 24
FWCI
17.94
Type
journal article
Language
en
Open access
Locations
  • Journal of Biological Chemistry (publishedVersion, cc-by)
  • PubMed (publishedVersion)
Funders
  • National Institutes of Health (5r01ag012685-04)
  • National Institute on Aging (AG06656, R01AG006656, AG12685)
Topics
  • Life Sciences › Neuroscience › Cellular and Molecular Neuroscience › Alzheimer's disease research and treatments
  • Health Sciences › Medicine › Psychiatry and Mental health › Dementia and Cognitive Impairment Research
  • Life Sciences › Neuroscience › Neurology › Neuroinflammation and Neurodegeneration Mechanisms
Keywords
amyloid-beta, Alzheimer's disease, amyloid-beta 42, Aβ40, cerebral amyloid angiopathy, amyloid plaques, cerebral cortex, vascular wall, amyloid deposition, cerebrospinal fluid
MeSH terms
Alzheimer Disease, Cerebral Cortex, Chromatography, Gel, Enzyme-Linked Immunosorbent Assay, Humans, Immunohistochemistry, Reference Values, Temporal Lobe, Amyloid beta-Peptides

About these checks

Registry, retraction, Cites and statistics results are computed, not judged, with one exception: a printed reference that no index lists is read once by a model before it counts as a citation error. Claims are extracted by a model and kept only when their quote appears verbatim in the text; each cited source is then checked, with a model’s help, for whether it says what the claim relies on. Those verdicts can be wrong — read the claim’s quote and the cited source before relying on one.

A language model drew the claims from the paper on 2026-10-27, under version 3 of the claim definition (model deepseek-v4.1-flash, prompt extract-v3).

A second model labelled each claim on 2026-10-27 (model jev-1.13-20260917, definition revision gold-guideline-v0.2).

Statistics and arithmetic are recomputed, not judged.

Confidence bands are shown only for fields calibrated on our annotated test set. None is calibrated yet, so no band is shown.

What counts as a claim ›How we measure confidence ›How we check this ›

Are you an author, or do you see a problem with this page? Request a review