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Encephalopathy with idiopathic hyperammonaemia and Alzheimer type II astrocytes in equidae
Hasel KM, Summers BA, De Lahunta A.. Equine veterinary journal, 1999-11-01
Topic: Brain proteins, microglia and lab models
In 3 mature female horses of varying breeds, episodes of colic and depression for 14 days preceded an encephalopathic disorder with maniacal behaviour, anxiety, profuse sweating and, in one case, terminal opisthotonus. Blood ammonia levels were elevated approximately 10-fold. At necropsy, there were gastrointestinal serosal and mesenteric haemorrhages. Histologically, all 3 cases revealed diffuse Alzheimer type II astrocytes in the cerebral grey matter. Alzheimer type II astrocytes were glial fibrillary acidic protein (GFAP) negative or only weakly positive, weakly S-100 positive, and vimentin negative. In the absence of primary hepatic and/or renal lesions, an increase in intestinal ammonia absorption due to ileus or increased ammonia production by colonic bacteria is hypothesised.
Cite this study APA, Vancouver, BibTeX · download .bib or .ris
APA 7th
Hasel, K. M., Summers, B. A., & De Lahunta, A. (1999). Encephalopathy with idiopathic hyperammonaemia and Alzheimer type II astrocytes in equidae. Equine veterinary journal. https://doi.org/10.1111/j.2042-3306.1999.tb03854.x
Vancouver
Hasel KM, Summers BA, De Lahunta A. Encephalopathy with idiopathic hyperammonaemia and Alzheimer type II astrocytes in equidae. Equine veterinary journal. 1999. doi:10.1111/j.2042-3306.1999.tb03854.x. PMID: 10596928.
BibTeX
@article{hasel1999-10596928,
author = {Hasel, K. M. and Summers, B. A. and De Lahunta, A.},
title = {{Encephalopathy with idiopathic hyperammonaemia and Alzheimer type II astrocytes in equidae}},
journal = {Equine veterinary journal},
year = {1999},
doi = {10.1111/j.2042-3306.1999.tb03854.x},
pmid = {10596928},
url = {https://doi.org/10.1111/j.2042-3306.1999.tb03854.x}
}
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Key findings
- Histologically, all 3 cases revealed diffuse Alzheimer type II astrocytes in the cerebral grey matter.
Why it matters
This report describes three horses with high blood ammonia and a type of astrocyte change in the brain that shares a name with a finding seen in liver-related brain disease in people. It concerns horses with encephalopathy and does not test any treatment, prevention or cause of Alzheimer disease in humans.
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Study details
- Evidence strengthLow
How this study scored 36/100
Published in a peer-reviewed journal. Scored zero for study design, sample size, effect reported and randomised / blinded because the record does not state it.
| Component | Points | Why |
|---|---|---|
| Journal tier | 7 / 10 | Tier 3 — peer-reviewed journal (Equine veterinary journal) |
| Journal's citation record | 1 / 4 | Equine Veterinary Journal: journal h-index 136 (OpenAlex, 2026-10-29) |
| Study design | 0 / 12 | No study design recorded — scores zero, not guessed (not stated in the record — scored 0) |
| Strength of evidence | 1 / 5 | Rated “low” in our summary |
| Peer-review validation | 10 / 10 | Peer-reviewed. Published as an article in a named peer-reviewed journal. |
| How recent | 1 / 5 | 1999 — older than 20 years, still counted |
| Sample size | 0 / 4 | Participant count not stated — scores zero (not stated in the record — scored 0) |
| Effect reported | 0 / 3 | No effect size reported — scores zero (not stated in the record — scored 0) |
| Studied in people | 3 / 3 | Studied in people (pubmed indexes it as a clinical or observational study) |
| Randomised / blinded | 0 / 2 | No randomisation or blinding stated — scores zero (not stated in the record — scored 0) |
| Times cited | 3 / 7 | Cited 37 times (OpenAlex, 2026-10-10) |
| Citations per year | 1 / 5 | 1.3 citations a year over 29 year(s) since 1999 |
| Impact for its field and year | 2 / 6 | Cited 1.2× the average for papers of its field and year (OpenAlex FWCI) |
| Cited by studies here | 0 / 6 | No other study in this library cites it |
| Still being cited | 0 / 4 | Cited 1 times in 2024–2026 (2026 still in progress; OpenAlex) |
| Senior author's track record | 2 / 4 | Last-listed author Alexander de Lahunta: h-index 42 (OpenAlex, whole career) |
| Institution's track record | 2 / 3 | Cornell University: institution h-index 1,649 (OpenAlex) |
| Multi-centre collaboration | 1 / 3 | OpenAlex lists 2 institution(s) in 1 country |
| Indexed in PubMed | 2 / 2 | Indexed in PubMed (PMID 10596928) |
| Free to read | 0 / 2 | Behind a paywall — scores zero |
| Total | 36 / 100 | — |
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May need a subscription Unpaywall, Europe PMC and OpenAlex found no free copy of the full text (checked 10 Oct 2026), so the publisher may charge for it. The PubMed abstract is free.
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