timolol is a non-selective beta-adrenergic receptor antagonist administered for treating glaucoma, heart attacks and hypertension. in the present study, we set out to determine whether or not timolol can provoke cataract formation, thus the influence of timolol on the amyloid-type aggregation of crystallin was investigated. we then provided experimental evidence of crystallin aggregation and it...

beta-Amyloid is a 39- to 43-amino-acid neurotoxic peptide that aggregates to form the core of Alzheimer disease-associated senile (amyloid) plaques. No satisfactory hypothesis has yet been proposed to explain the mechanism of beta-amyloid aggregation and toxicity. We present mass spectrometric and electron paramagnetic resonance spin trapping evidence that beta-amyloid, in aqueous solution, fra...

In Alzheimer's disease (AD), abnormal accumulations of beta-amyloid are present in the brain and degenerating neurons exhibit cytoskeletal aberrations (neurofibrillary tangles). Roles for beta-amyloid in the neuronal degeneration of AD have been suggested based on recent data obtained in rodent studies demonstrating neurotoxic actions of beta-amyloid. However, the cellular mechanism of action o...

BACKGROUND: Mauthner goldfish (Carassius auratus (L)) cells serve as model objects for studying brain pathologies at the level of identified neurons and their individual dendrites. L-dopa may be an agent that decelerates destruction caused by toxic effects beta-amyloid.
 AIMS: To study three-dimensional structure in ultrastructure afferent synapses under influence 2535 fragment MATERIAL AN...

beta-amyloid levels are elevated in Down syndrome (DS) patients throughout life and are believed to cause Alzheimer's disease (AD) in adult members of this population. However, it is not known if beta-amyloid contributes to intellectual disability in younger individuals. We used a gamma-secretase inhibitor to lower beta-amyloid levels in young mice that model DS. This treatment corrected learni...

PURPOSE To compare the temporal and spatial expression patterns of amyloid precursor protein (APP), amyloid-beta deposits, inflammatory chemokines, and apoptosis in the retina of a mouse model of Alzheimer disease (AD). METHODS Retinas of transgenic mice harboring a mutant presenilin (PS1) and a mutant APP gene were processed for TUNEL and immunohistochemistry with antibodies against APP, amy...

Accumulation of inflammatory microglia in Alzheimer's senile plaques is a hallmark of the innate response to beta-amyloid fibrils and can initiate and propagate neurodegeneration characteristic of Alzheimer's disease (AD). The molecular mechanism whereby fibrillar beta-amyloid activates the inflammatory response has not been elucidated. CD36, a class B scavenger receptor, is expressed on microg...

Using immunohistochemical staining methods with antibodies to amyloid beta protein and human cystatin C, we examined cerebrovascular amyloid protein in the brains from 46 cases with cerebral amyloid angiopathy (seven with Alzheimer's disease, one with Down's syndrome, 18 with intracranial hemorrhage, 10 with cerebral infarction, and 10 elderly patients without any neurologic disorder). All cere...

The 25-35 fragment of the amyloid β (Aβ) peptide is a naturally occurring proteolytic by-product of its larger parent molecule that retains the amyloid characteristics and toxicity of the full length parent molecule. Aggregation of this peptide occurs rapidly in aqueous solutions and thus characterization of its folding process is very difficult. In the present study, early stages of Aβ(25–35) ...

Acetylcholinesterase (AChE), an important component of cholinergic synapses, colocalizes with amyloid-beta peptide (A beta) deposits of Alzheimer's brain. We report here that bovine brain AChE, as well as the human and mouse recombinant enzyme, accelerates amyloid formation from wild-type A beta and a mutant A beta peptide, which alone produces few amyloid-like fibrils. The action of AChE was i...