In the world's largest brain study to date, a team of more than 200 scientists from 100 institutions worldwide collaborated to map the human genes that boost or sabotage the brain's resistance to a variety of mental illnesses and Alzheimer's disease. Published in the advance online edition of Nature Genetics, the study also uncovers new genes that may explain individual differences in brain size and intelligence. "We searched for two things in this study, " said senior author Paul Thompson, professor of neurology at the David Geffen School of Medicine at UCLA and a member of the UCLA Laboratory of Neuro Imaging. "We hunted for genes that increase your risk for a single disease that your children can inherit. We also looked for factors that cause tissue atrophy and reduce brain size, which is a biological marker for hereditary disorders like schizophrenia, bipolar disorder, depression, Alzheimer's disease and dementia .
O-GlcNAc Regulatory System Adds Complexity In Cell Regulation, Could Eventually Provide New Drug Targets
In Alzheimer's disease, brain neurons become clogged with tangled proteins. Scientists suspect these tangles arise partly due to malfunctions in a little-known regulatory system within cells. Now, researchers have dramatically increased what they know about this particular regulatory system in mice. Such information will help scientists better understand Alzheimer's and other diseases in humans and could eventually provide new targets for therapies. In a study released online in the Proceedings of the National Academy of Sciences Early Edition this week, the team at least doubled the number of proteins found to be subject to a type of regulation based on a sugar known as O-GlcNAc (oh-GLIK-nak). The O-GlcNAc system likely adds another layer of control to the proteins that serve as a brain cell's widgets and gears - control that might be muddled in Alzheimer's brains known to have problems in sugar metabolism.
A research team led by the University of South Florida Department of Psychiatry & Behavioral Neurosciences has found that a fragment of the amyloid precursor protein (APP) - known as sAPP-Î and associated with Alzheimer's disease - appears to regulate its own production. The finding may lead to ways to prevent or treat Alzheimer's disease by controlling the regulation of APP. Their study is published online in Nature Communications. "The purpose of this study was to help better understand why, in most cases of Alzheimer's disease, the processing of APP becomes deregulated, which leads to the formation of protein deposits and neuron loss, " said study senior author Dr. Jun Tan, professor of psychiatry and the Robert A. Silver Chair, Rashid Laboratory for Developmental Neurobiology at the USF Silver Child Development Center.
Investigators from the University of Amsterdam, Netherlands, have shown that in most elderly patients invasive and expensive techniques, i.e. lumbar puncture and PET scan, are not useful to establish the diagnosis of Alzheimer's disease. They arrived at this conclusion after analysis of data from the Alzheimer's Disease Neuroimaging Initiative (ADNI), a large collaborative research project of medical centers in the USA and Canada. The Dutch researchers divided the ADNI sample into two halves, a younger ( 74 y). They showed that the CSF biomarkers (amyloid and tau), and FDG- PET, are informative in the younger but not in the older patients. In the older patients MRI scans and neuropsychological tests appeared to convey useful information, but CSF biomarkers and FDG-PET did not. The latter two techniques are informative only in younger patients.
A study published Online First by Archives of Internal Medicine, one of the JAMA/Archives journals, reveals that antipsychotic drugs can increase the risk of heart attack in older patients with dementia. Older patients with dementia are often prescribed antipsychotics in order to control symptoms, such as hallucinations, physical aggression, and agitation. Earlier studies have indicated that the use of antipsychotic agents (APs) was associated to an increased risk of stroke, as well as death from all causes. As a result, safety warnings were issued in several countries. However, the risk of acute myocardial infarction (MI) with the use of APs in patients treated with dementia "remains poorly examined." Using the Quebec, Canada, prescription claims database, Antoine Pariente, M.