Research

Analyses of cerebrospinal fluid from 15 patients with Alzheimer's disease, 20 patients with mild cognitive impairment, and 21 control subjects, plus brain tissue from some of them, has found that those with Alzheimer’s had lower levels of a particular molecule involved in resolving inflammation. These ‘specialized pro-resolving mediators’ regulate the tidying up of the damage done by inflammation and the release of growth factors that stimulate tissue repair. Lower levels of these molecules also correlated with a lower degree of cognitive function.

Tau protein stabilizes structures that transport supplies from the center of the cell to the extremities, but sometimes some tau is not bound to these microtubules and instead clumps together into neurofibrillary tangles — one of the hallmarks of Alzheimer's disease, and also linked to other neurodegenerative disorders. A new study supports the theory that ‘bad’ tau travels to different brain regions via the synapses — that is, it’s secreted with the signals passing between neurons.

A study involving genetically engineered fruit flies adds to our understanding of why sleep and bioclock disruptions are common in those with Alzheimer's disease. People with Alzheimer's often have poor biological rhythms — periods of sleep become shorter and more fragmented, resulting in periods of wakefulness at night and snoozing during the day. It has been thought that Alzheimer’s destroys the biological clock, but this new study indicates that the clock is still working — however, it’s being ignored by other parts of the brain.

A new study shows that a combination of inflammation and hypoxia activates microglia in a way that persistently weakens the connection between neurons, contributing to brain damage in conditions such as stroke and Alzheimer's disease.

http://www.eurekalert.org/pub_releases/2014-03/uobc-scb031214.php

Brain scans of 10 persons with Down syndrome but no dementia, 10 persons with Down syndrome and dementia, and 10 healthy controls, have revealed a linear correlation between cognitive ability and compromised white matter connections in the frontal lobes among those with Down syndrome. Those with higher cognitive ability and motor skill coordination had healthier white matter integrity, and those with additional dementia showed the most deterioration.

Adults with Down Syndrome are known to be at high risk of developing Alzheimer’s after age 40.

A new function has been found for the amyloid precursor protein (APP), which may help explain how it goes awry in Alzheimer's disease. It appears that APP (which is involved in the creation of amyloid-beta), also helps control the growth and maturation of newborn brain cells, by regulating a specific microRNA (microRNA-574-5p) that normally promotes neurogenesis.

http://www.eurekalert.org/pub_releases/2014-04/s-nrd041814.php

New research helps explain the role of amyloid-beta plaques in the development of Alzheimer's, by finding that the prion protein known to bind strongly to small aggregates of amyloid-beta peptides, also attaches to large fibrillar clumps of amyloid-beta. However, it doesn’t break them down into smaller, more harmful pieces, as has been suggested. This suggests that prion-protein-based compounds might be a useful means of treatment, to stop these smaller pieces from forming.

Creating amyloid-beta requires the convergence of a protein called amyloid precursor protein (APP) and an enzyme that cleaves APP into smaller toxic fragments (beta-secretase or BACE). Both APP and BACE are common in the brain, so why don’t we all get Alzheimer’s?

A Finnish study involving moderately obese adult patients with mild obstructive sleep apnea (OSA) has found that even a modest weight loss (5%) can improve OSA, if occurring in the early stages of OSA.

http://www.eurekalert.org/pub_releases/2014-02/uoef-emw021114.php

Data from a survey of 20,000 people across the UK has found that people who cycle, walk, or take public transport to work had a lower risk of being overweight than those who drove or took a taxi. People who walked to work were 40% less likely to have diabetes than those who drove and 17% less likely to have high blood pressure. Cyclists were around half as likely to have diabetes as drivers.

http://www.eurekalert.org/pub_releases/2013-08/icl-wtw080513.php