The revised Approved Instructional Resources score: An improved quality evaluation tool for online educational resources.

Background: Free Open-Access Medical education (FOAM) use among residents continues to rise. However, it often lacks quality assurance processes and residents receive little guidance on quality assessment. The Academic Life in Emergency Medicine Approved Instructional Resources tool (AAT) was created for FOAM appraisal by and for expert educators and has demonstrated validity in this context.

Synchrotron XRF imaging of Alzheimer's disease basal ganglia reveals linear dependence of high-field magnetic resonance microscopy on tissue iron concentration.

Background: Chemical imaging of the human brain has great potential for diagnostic and monitoring purposes. The heterogeneity of human brain iron distribution, and alterations to this distribution in Alzheimer's disease, indicate iron as a potential endogenous marker. The influence of iron on certain magnetic resonance imaging (MRI) parameters increases with magnetic field, but is under-explored in human brain tissues above 7 T.

Iron deficiency in parkinsonism: region-specific iron dysregulation in Parkinson's disease and multiple system atrophy.

Alpha synuclein pathology is widespread and found in diverse cell types in multiple system atrophy (MSA) as compared to Parkinson's disease (PD). The reason for this differential distribution is unknown. Regional differences in the distribution of iron are associated with neurodegenerative diseases, and here we characterize the relationship between iron homeostasis proteins and regional concentration, distribution and form of iron in MSA and PD.

The aluminium content of breast tissue taken from women with breast cancer.

The aetiology of breast cancer is multifactorial. While there are known genetic predispositions to the disease it is probable that environmental factors are also involved. Recent research has demonstrated a regionally specific distribution of aluminium in breast tissue mastectomies while other work has suggested mechanisms whereby breast tissue aluminium might contribute towards the aetiology of breast cancer.

Brain burdens of aluminum, iron, and copper and their relationships with amyloid-β pathology in 60 human brains.

The deposition in the brain of amyloid-β as beta sheet conformers associated with senile plaques and vasculature is frequently observed in Alzheimer’s disease. While metals, primarily aluminum, iron, zinc, and copper, have been implicated in amyloid-β deposition in vivo, there are few data specifically relating brain metal burden with extent of amyloid pathologies in human brains. Herein brain tissue content of aluminum, iron, and copper are compared with burdens of amyloid-β, as senile plaques and as congophilic amyloid angiopathy, in 60 aged human brains.

Aluminium, iron and copper in human brain tissues donated to the Medical Research Council's Cognitive Function and Ageing Study.

Aluminium, iron and copper are all implicated in the aetiology of neurodegenerative diseases including Alzheimer's disease. However, there are very few large cohort studies of the content of these metals in aged human brains. We have used microwave digestion and TH GFAAS to measure aluminium, iron and copper in the temporal, frontal, occipital and parietal lobes of 60 brains donated to the Cognitive Function and Ageing Study.

Spherulites in human brain tissue are composed of β sheets of amyloid and resemble senile plaques.

Recent evidence showed that amyloid-β, Aβ(42), formed spherulites in vitro and, possibly, in vivo in Alzheimer's disease brain tissue. We now confirm the presence of spherulites in human brains and that they are composed of β sheets of amyloid. The spherulites were identical in appearance to spherulites of Aβ(42) formed in vitro which suggested that they may too be composed of Aβ.

Human pro-islet amyloid polypeptide (ProIAPP(1-48)) forms amyloid fibrils and amyloid spherulites in vitro.

Deposition of beta sheets of islet amyloid polypeptide (IAPP) in pancreatic tissue is implicated in the aetiology of type 2 diabetes mellitus (T2DM). IAPP is cleaved from its precursor protein, pro-islet amyloid polypeptide (ProIAPP) and incomplete cleavage results in ProIAPP(1-48), which is found co-deposited with IAPP. Cu(II) prevents IAPP from forming amyloid and herein we investigated if it would also prevent ProIAPP(1-48) from forming beta sheets.

Spherulites of amyloid-beta42 in vitro and in Alzheimer's disease.

Several amyloidogenic proteins including insulin, beta-lactoglobulin, and albumin form spherulites in vitro under non-physiological conditions. These micrometer-sized, roughly spherical structures are composed of ordered arrays of amyloid fibrils in radial arrangements which, characteristically, show a typical Maltese cross pattern of light extinction under the polarizing microscope. The physiological significance of amyloid spherulites is unknown though in Alzheimer's disease, senile plaques composed primarily of beta sheets of amyloid-beta (Abeta)42 have, very occasionally, been shown to give a Maltese cross pattern of light extinction under crossed polarizers.

Copper abolishes the beta-sheet secondary structure of preformed amyloid fibrils of amyloid-beta(42).

The observation of the co-deposition of metals and amyloid-beta(42) (Abeta(42)) in brain tissue in Alzheimer's disease prompted myriad investigations into the role played by metals in the precipitation of this peptide. Copper is bound by monomeric Abeta(12) and upon precipitation of the copper-peptide complex thereby prevents Abeta(42) from adopting a beta-sheet secondary structure. Copper is also bound by beta-sheet conformers of Abeta(42), and herein we have investigated how this interaction affects the conformation of the precipitated peptide.

Aluminium, iron, zinc and copper influence the in vitro formation of amyloid fibrils of Abeta42 in a manner which may have consequences for metal chelation therapy in Alzheimer's disease.

Metals are found associated with beta-pleated sheets of Abeta42 in vivo and may be involved in their formation. Metal chelation has been proposed as a therapy for Alzheimer's disease on the basis that it may safely dissolve precipitated Abeta peptides. We have followed fibrillisation of Abeta42 in the presence of an additional metal ion (Al(III), Fe(III), Zn(II), Cu(II)) over a period of 32 weeks and we have investigated the dissolution of these aged peptide aggregates in the presence of both desferrioxamine (DFO) and ethylenediaminetetraacetic acid (EDTA).