28, July 2014

Night lights can wake up breast cancer cells

Sleeping at night with the lights on can not only add to your energy consumption, but also wake up breast cancer cells, a study suggests.

Exposure to light at night, which shuts off night-time production of the hormone melatonin, renders breast cancer completely resistant to tamoxifen, a widely-used breast cancer drug, the findings showed.

"High melatonin levels at night put breast cancer cells to 'sleep' by turning off key growth mechanisms. These cells are vulnerable to tamoxifen. But when the lights are on and melatonin is suppressed, breast cancer cells 'wake up' and ignore tamoxifen," said David Blask from the Tulane University in the US.

The researchers investigated the role of melatonin on the effectiveness of tamoxifen in combating human breast cancer cells implanted in rats.

Melatonin by itself delayed the formation of tumours and significantly slowed their growth but tamoxifen caused a dramatic regression of tumours in animals with either high night-time levels of melatonin during complete darkness or those receiving melatonin supplementation during dim light at night exposure.

These findings have potentially enormous implications for women being treated with tamoxifen and also regularly exposed to light at night due to sleep problems, working night shifts or exposed to light from computer and TV screens.

The study appeared in the journal Cancer Research.

Source: www.timesofindia.com

28.07.2014

Virus linked to obesity and diabetes found

Biologists have discovered an extremely widespread virus that could be as old as humans and could play a major role in obesity and diabetes.

More than half of the world's population is host to the newly described virus, named crAssphage, which infects one of the most common types of gut bacteria, Bacteroidetes, the findings showed.

This phylum of bacteria is thought to be connected with obesity, diabetes and other gut-related diseases.

"It is not unusual to go looking for a novel virus and find one. But it is very unusual to find one that so many people have in common. The fact that it has flown under the radar for so long is very strange," said Robert Edwards, a bioinformatics professor at the San Diego State University in the US.

In the DNA fecal samples from 12 different individuals, the researchers noticed a particular cluster of viral DNA, about 97,000 base pairs long, that the samples all had in common.

When Edwards and his colleagues checked this discovery against a comprehensive listing of known viruses, they came up empty.

This was a new virus that about half the sampled people had in their bodies that nobody knew about.

The fact that it is so widespread indicates that it probably is not a particularly young virus, either.

"We have basically found it in every population we have looked at," Edwards said.

"As far as we can tell, it is as old as humans are," he added.

The study appeared in the journal Nature Communications.

Source: www.timesofindia.com

28.07.2014

The pain you feel today is the strength you'll feel tomorrow