In brief

March/April 2017   Comments

A gut feeling about age-related macular degeneration

Age-related macular degeneration (AMD) is the leading cause of irreversible blindness in the industrialized world. In a study published in EMBO Molecular Medicine, a Montreal-based research team discovered that one’s intestinal bacteria may play an important role in determining if the individual will develop the late-stage form of the disease, called wet AMD. Currently available treatments decrease in effectiveness over time, so it is important to find new ways to prevent this debilitating disease.

Using mice, the researchers found that changes in the bacterial communities of the gut, such as those brought on by a diet rich in fat, can cause long-term low-grade inflammation throughout the body and eventually stimulate the development of wet AMD. In one experiment, the investigators transferred gut microbes from the feces of mice receiving a regular-fat diet into mice receiving a high-fat diet, which resulted in a significant decrease in wet AMD development in the mice on the high-fat diet. It may therefore be possible for people to reduce their risk of developing wet AMD by influencing the types of microbes that live in their gut through diet or by other means.

New tool on the horizon to tame food allergies

University of Saskatchewan scientists have developed an immunotherapy technique that nearly eliminates the allergic response to peanut and egg white proteins in allergic mice. Food allergy is a growing public health issue in Canada. According to the Canadian Institute for Health Information, an estimated 171,000 Canadians visited emergency departments for allergic reactions from 2013 to 2014, and the severity of reactions is increasing.

Published in the Journal of Allergy and Clinical Immunology, the discovery involves generating a type of naturally occurring immune cell that sends a signal to reverse the hyper-immune response present in allergic reactions. That signal turns off reactive cells further along the allergic pathway. The treatment reduced the observed symptoms of anaphylaxis and lowered other key protein markers in the allergic response by up to 90 per cent.

With Health Canada approval, the first human trial could begin in about a year, and the researchers predict the treatment could be on the market within the next five to 10 years. The new technique also shows promise for treating autoimmune disorders such as multiple sclerosis.

Re-establishing brain communication in early Alzheimer’s disease

A team led by University of British Columbia researchers has found a way to partially restore cell communication around areas of the brain damaged by the plaques of ß-amyloid deposits that develop in Alzheimer’s disease. Working with mice, the researchers found that glutamate, a signalling molecule, accumulates around these plaques, and the brain cells are not able to remove it. In this glutamate-rich environment, the communication between brain cells is changed or disrupted, causing them to die in the later stages of the disease. The team discovered they could restore glutamate to its normal level with ceftriaxone, an antibiotic used to treat bacterial infections. As a result, they were able to mostly restore brain cell activity.

The lead author said that this discovery, published in Nature Communications, is particularly interesting because the dysfunction in cell communication occurs at a very early stage in the disease, before memory impairment is detectable. It therefore opens a window for an intervention strategy to possibly prevent or delay brain cell and memory loss in patients who are at the beginning stages of Alzheimer’s disease.

The key to a happy sex life

The secret to lasting sexual satisfaction in long-term relationships is the belief that it takes hard work, instead of expecting sexual satisfaction to simply happen if you are true soulmates, according to a study led by a University of Toronto researcher. Her team examined two types of beliefs: that maintaining sexual satisfaction over time takes effort and that sexual satisfaction is achieved by finding a compatible partner (i.e., it is a matter of destiny). The lead investigator noted that those in the first group believe they can work on their sexual problems and don’t let them affect their relationship satisfaction. In contrast, people in the second group are using their sex life as a barometer for how well their relationship is doing, and they believe problems in the bedroom indicate problems in the relationship as a whole.

Published in the Journal of Personality and Social Psychology, the findings are based on research involving about 1,900 participants, in heterosexual and same-sex relationships. The findings underscore the importance for counsellors and clinicians to promote the idea that problems in the bedroom are normal and don’t automatically mean the relationship is in trouble.

Game-changing blood test for concussions

It is often challenging to determine whether someone has a clinically significant concussion, as diagnosis is typically based on a combination of patient symptom assessment and clinician judgment. In a study published in Metabolomics, scientists from Western University and the Lawson Health Research Institute demonstrated that concussions in adolescent athletes can now be diagnosed with greater than 90 per cent certainty with a relatively inexpensive blood test, using a form of blood profiling known as metabolomics.

Other research teams have looked unsuccessfully for a single highly accurate protein biomarker to distinguish concussed from non-concussed adolescent patients. In this new study, the scientists measured a panel of 174 metabolites — small molecules that are the products of the body’s metabolism — in the blood of adolescent male hockey players to search for distinct patterns that indicate a concussion has occurred. They found that athletes who have had a concussion have a very different pattern of these metabolites than those who have not. With fine tuning, the researchers were able to look at sets of as few as 20-40 metabolites and maintain the diagnostic accuracy of the test. They anticipate that clinicians will eventually be able to also use the test to predict concussion outcome and make decisions about rehabilitation after concussion.

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