Beta-amyloid peptides (A beta peptides) form the main protein component of the amyloid deposits found in the brains of Alzheimer's disease (AD) patients. Soluble A beta peptides, which are proteolytic fragments of the amyloid-precursor protein (APP) are constitutively secreted by cells expressing APP during normal metabolism [1] and are also present in human plasma and cerebrospinal fluid [2]. Missense mutations in Codon 717 of the APP gene are responsible for a small percentage of inherited AD cases (FAD) and increase the amount of A beta peptides containing additional carboxy terminal amino acids (A beta 1-42, A beta 1-43) [3, 4]. Recent findings indicate that FAD mutations in the presenilin 1 and 2 genes also increase the amount of these longer A beta peptides [5]. A beta 1-42 polymerizes more rapidly in vitro [6] than A beta 1-40 and has been identified as the major component of the brain amyloid deposits [7-9]. We recently developed a sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) system [10] for the separation of these two peptides. Here we describe a modified version of the original SDS-PAGE procedure, which allows the separation of A beta 1-40, A beta 1-42, and A beta 1-43 for the first time. Detection of the three A beta peptides in the lower ng and pg range is realized by optimized silver staining or immunoblot procedures. These nonradioactive methods may validate results obtained by ELISA procedures used to study the metabolic fate of APP. They may help to define the neurotoxic potential of the longer A beta peptides in relation to their aggregation state.

Amyloid beta-Peptides↗

PubMedDate not supplied

Temporal bone showing otosclerosis, paget's disease and adenocarcinoma.

In a pair of temporal bones serial sectioning revealed widespread Paget's disease with otosclerosis on both sides and, at the right side, adenocarcinoma added. Stapedial fixation was produced on the right by otosclerosis, and on the left by Paget's disease. In the contest to reach the inner cochlear space, Paget was the winner on the left, where, at the tympanic scala, otosclerosis and Paget's disease almost met, while the immediately adjacent organ o Corti was uninvolved.

Adenocarcinoma↗

PubMedDate not supplied

Temporal bone findings in cases of salt water drowning.

The otologic literature contains no description of the histopathological features of temporal bones of persons who perished in drowning accidents. Three temporal bones from two fatal cases of drowning were studied in serial sections. Two temporal bones were from a man aged 31 years who collapsed after scuba diving and died three days later. One temporal bone was from a 32-year-old man, serving in the navy, who drove his car, probably accidentally, into the sea and drowned in it. Histopathological findings appeared to be similar in the two cases. Diffuse hemorrhage was evident throughout the middle ear and inner ear. The tympanic and round window membranes appeared to be intact although hemorrhage had occurred within the tissue layers of the membranes. This finding contrasts with observations of ruptured membranes by other investigators.

Adult↗

PubMedDate not supplied

Non-experimental aural pathology in some Prosimii.

Explore the source record for details and available documents.

Anatomy, Comparative↗

PubMedDate not supplied

Penetration of the cochlear endost by the fibrous component of the otosclerotic focus.

The role of the "third", "fibrous" component of the otosclerotic focus in penetrating and absorbing the cochlear endost is documented. An otosclerotic focus rich in fibrous-granulomatous component shows equal power as spongiotic or sclerotic components producing fragmentation resulting in rosary-formed absorption of the endost opening access to the soft-tissue containing regions of the cochlea.

Cochlea↗

PubMedDate not supplied

[Disorder of the inner ear in diabetics].

Explore the source record for details and available documents.

Abortion, Therapeutic↗