Cardiac disease-dementia link found

Singapore researchers have uncovered a link between cardiac diseases and tiny brain lesions commonly found in patients with cognitive impairment or dementia.

The team of cardiovascular and brain researchers from the National University Health System (NUHS) studied 243 elderly participants, who were on average 72 years old. They found that the presence of tiny brain lesions, called cerebral microinfarcts (CMIs), was strongly associated with cardiac disease and blood cardiac biomarkers - molecules or genes linked to the condition. A rise in cardiac markers was accompanied by an increased risk of developing CMIs, the findings showed.

"Our findings suggest that the development of these tiny brain lesions, which are closely linked to diseases like dementia, may be caused by chronic heart problems and vascular disease," said Associate Professor Christopher Chen, director of NUHS' Memory Ageing and Cognition Centre.

Apart from signalling problems with the heart, cardiac biomarkers are also indicators of injury to circulatory and blood vessel systems in other organs, for example the brain, said Prof Arthur Mark Richards, director of NUHS' Cardiovascular Research Institute.

"Our selected cardiac markers are powerful predictors of the presence of CMIs and cognitive impairment, and may provide scientists and clinicians with tools for the prevention or timely treatment of brain-related diseases."

The findings were published in scientific journal JAMA Neurology, a journal of the American Medical Association.

The team plans to expand the study to better understand the role that cardiac dysfunction plays in the development of CMIs, and if the findings are applicable to non-Asian populations who may have different risk profiles.

These future studies may help to determine if treatments for cerebrovascular disease-related (relating to the brain and its blood vessels) cognitive impairment can be achieved by targeting cardiac disease, the team said.

Fish venom may inspire pain treatment

Tiny fanged fish called blennies, which swim in the coral reefs of the Pacific Ocean, are armed with an unusual venom that could inspire new pain medications, British and Australian scientists have found.

The venom of these 4cm to 7cm swimmers - which are popular tropical aquarium fish - numbs would-be predators, said the scientists in a paper published in scientific journal Current Biology.

"The fish injects other fish with opioid peptides that act like heroin or morphine, inhibiting pain rather than causing it," said Associate Professor Bryan Fry of the University of Queensland. "The venom causes the bitten fish to become slower in movement and dizzy by acting on their opioid receptors."

Experiments using lab mice found the rodents showed no sign of pain once injected with the fish venom. Prof Fry said the venom is "chemically unique" and called the fang blennies "the most interesting fish I've ever studied".

Their behaviour is also intriguing, he said, for the way they appear unafraid of predators and fight for territory with similar-sized fish.

Prof Fry said the findings bolster the need to protect the Great Barrier Reef and other fragile ecosystems.

"If we lose the Great Barrier Reef, we will lose animals like the fang blenny and its unique venom that could be the source of the next blockbuster pain-killing drug," he said.

AGENCE FRANCE-PRESSE

Loneliness may worsen cold symptoms

If you are lonely, symptoms of the common cold may be more pronounced, according to Rice University researchers.

A study led by Rice University psychologist Chris Fagundes and graduate student Angie LeRoy indicated lonely people are more prone to report that their cold symptoms are more severe than those who have stronger social networks.

A paper on the study was published in Health Psychology. A total of 159 people aged 18 to 55 were assessed for their psychological and physical health, given cold-inducing nasal drops and quarantined for five days in hotel rooms.

The participants, scored in advance on the Short Loneliness Scale and the Social Network Index, were monitored during and after the five-day stay.

After adjusting for demographics like gender and age, the season, depressive effect and social isolation, the results showed those who were screened in advance for their level of loneliness and became infected reported a greater severity of symptoms than those recorded in previous studies used as controls. The size of the participants' social networks appeared to have no bearing on how sick they felt.

The effect may be the same for those under other kinds of stress, Dr Fagundes said in a statement by the university.

"Any time you have an illness, it's a stressor, and this phenomenon would probably occur," he said. "A predisposition, whether it's physical or mental, can be exaggerated by a subsequent stressor. In this case, the subsequent stressor is getting sick, but it could be the loss of a loved one, or getting breast cancer, which are subjects we also study."

Compiled by Samantha Boh