The fountain of youth may reside in an embryonic stem cell gene named Nanog, suggests new research that may lead to treatments for conditions due to reduced bone strength, Alzheimer's and other age-related disorders.

In a series of experiments at the University at Buffalo in New York, the gene kicked into action dormant cellular processes that are key to preventing weak bones, clogged arteries and other telltale signs of growing old.

"Our research into Nanog is helping us to better understand the process of ageing and ultimately how to reverse it," said the study's lead author Stelios Andreadis, Professor at the University at Buffalo School of Engineering and Applied Sciences.

The findings, published in the journal Stem Cells, also showed promise in counteracting premature ageing disorders such as Hutchinson-Gilford progeria syndrome.

To battle ageing, the human body holds a reservoir of non-specialised cells that can regenerate organs.

These cells are called adult stem cells, and they are located in every tissue of the body and respond rapidly when there is a need.

But as people age, fewer adult stem cells perform their job well, a scenario which leads to age-related disorders.

Reversing the effects of ageing on adult stem cells, essentially rebooting them, can help overcome this problem.

In the new study, Panagiotis Mistriotis, a graduate student in Andreadis' lab and first author of the study, introduced Nanog into aged stem cells.

He found that Nanog opens two key cellular pathways that jumpstarts dormant proteins into building cytoskeletons that adult stem cells need to form muscle cells that contract.

Force generated by these cells ultimately helps restore the regenerative properties that adult stem cells lose due to ageing.

"Not only does Nanog have the capacity to delay aging, it has the potential in some cases to reverse it," Andreadis said.

The researchers are now focusing on identifying drugs that can replace or mimic the effects of Nanog. This will allow them to study whether aspects of aging inside the body can also be reversed.

London: Women indulging in smoking are more at risk of developing bleeding inside the lining of the brain, also known as subarachnoid hemorrhage, a study has warned.

Subarachnoid hemorrhage is a condition of bleeding in the lining between the brain's surface and underlying brain tissues.

The findings showed that although cigarette smoking was linked to an increased risk of subarachnoid hemorrhage among both sexes, women faced the highest risk.

"Female sex has been described as an independent risk factor for subarachnoid hemorrhage, but we found strong evidence that the elevated risk in women is explained by vulnerability to smoking," said lead author Joni Valdemar Lindbohm, Physician at the University of Helsinki in Finland.

Further, among light smokers (1 to 10 cigarettes per day), women were 2.95 times more likely to have subarachnoid hemorrhage compared to non-smokers, while men who smoked comparable amounts of cigarettes were 1.93 times more likely.

Women who smoked 11 to 20 cigarettes per day were 3.89 times more likely to have subarachnoid hemorrhage compared to non-smokers, while men who smoked comparable amounts of cigarettes were 2.13 times more likely.

Women who smoked 21 to 30 cigarettes per day were more than 8.35 times likely to have subarachnoid hemorrhage compared to non-smokers, while men who smoked comparable amounts of cigarettes were 2.76 times more likely.

"Our results suggest that age, sex and lifestyle risk factors play a critical role in predicting which patients are at risk for subarachnoid hemorrhage and emphasise the importance of effective smoking cessation strategies," Lindbohm explained.

However, quitting smoking has been found to significantly decrease the risk among former smokers.

"There is no safe level of smoking," Lindbohm said, adding "naturally the best option is never to start. Quitting smoking, however, can reduce the risk for subarachnoid hemorrhage in both sexes."

In addition, subarachnoid hemorrhage also accounts for three per cent of all strokes, according to the American Heart Association.

Smoking is perhaps the most important modifiable risk factor in preventing subarachnoid hemorrhage, with the highest population attributable risk of any subarachnoid hemorrhage risk factor, the researchers noted.

For the study, published in the journal Stroke, the team included 65,521 adults from Finish national surveys.

Slightly more than half of participants were women, and their average age was 45 years. The average follow-up was 21 years from study enrolment until first stroke, death or study completion on December 31, 2011.

When cows are happy, they produce more nutritious milk with higher levels of calcium, new research suggests.

The researchers found that daily infusions with a naturally-occurring chemical commonly associated with feelings of happiness increased calcium levels in the milk of Jersey cows that had just given birth.

The results, published in the Journal of Endocrinology, could lead to a better understanding of how to improve the health of dairy cows, and keep the milk flowing.

Demand is high for milk rich in calcium and dairy products such as milk, cheese and yoghurt are primary sources of the mineral.

But this demand can take its toll on milk-producing cows as evident from the fact that a large number of dairy cow population suffers from hypocalcaemia -- in which calcium levels are low.

A team of researchers led by Laura Hernandez from the University of Wisconsin-Madison in the US investigated the potential for serotonin (a naturally occurring chemical commonly associated with feelings of happiness) to increase calcium levels in both the milk and blood of dairy cows.

The team infused a chemical that converts to serotonin into 24 dairy cows, in the run up to giving birth.

Half the cows were Jersey and half were Holstein -- two of the most common breeds. Calcium levels in both the milk and circulating blood were measured throughout the experiment.

While serotonin improved the overall calcium status in both breeds, this was brought about in opposite ways.

Treated Holstein cows had higher levels of calcium in their blood, but lower calcium in their milk (compared to controls).

The reverse was true in treated Jersey cows and the higher milk calcium levels were particularly obvious in Jerseys at Day 30 of lactation -- suggesting a role for serotonin in maintaining levels throughout lactation.

"By studying two breeds we were able to see that regulation of calcium levels is different between the two," Hernandez said.

"Serotonin raised blood calcium in the Holsteins, and milk calcium in the Jerseys. We should also note that serotonin treatment had no effect on milk yield, feed intake or on levels of hormones required for lactation," she noted.

A new study has revealed that doing moderate-to-vigorous physical exercises such as brisk walking or jogging may boosts memory in breast cancer survivors.

The findings found that physical activity reduces stress and benefits women psychologically, which in turn aids their memory.

Memory problems appear to be related to the high stress load cancer survivors experience and may not be specific to chemotherapy or radiation treatments.

Siobhan Phillips, Assistant Professor, Northwestern University Feinberg School of Medicine in Chicago said, "Our research suggests these self-reported memory problems may be emotionally related. These women are frightened, stressed, fatigued, tapped out emotionally and have low self-confidence, which can be very mentally taxing and can lead to perceived memory problems".

The study were published in the journal Psycho-Oncology.

The researchers looked at memory and exercise in breast cancer survivors in two study arms - one in self-reported data for 1,477 women; the other in accelerometers worn by 362 women.

The findings linking improved memory to higher levels of physical activity were consistent across both groups.

In the study, more physical activity was associated with higher levels of self-confidence, lower distress and less fatigue, which in turn is associated with lower levels of perceived memory impairment.

Breast cancer survivors who had higher levels of moderate and vigorous physical activity - brisk walking, biking, jogging or attending an exercise class -- had fewer subjective memory problems. Subjective memory is an individual's perception of his/her memory.

A new study has linked a gene, which forms part of our body's first line of defence against infection, to an increased risk of a type of kidney disease.

The University of Nottingham study found that the difference in the number of copies of the alpha-defensin genes was a major genetic factor in developing the condition IgA nephropathy, also known as Berger's Disease.

Researcher John Armour said that the observation that variation in the gene numbers for these alpha-defensin genes is strongly correlated with risk of IgA nephropathy creates an interesting puzzle.

He added that the data overwhelmingly support the association, but researchers still don't understand what the connection might be between alpha-defensins and molecular events that cause the kidney problems.

The team looked at genetic variation in more than 1,000 patients with IgA nephropathy, compared with more than 1,000 people without the condition, and found a significant difference in the numbers of alpha-defensin genes between the two groups.

Alpha-defensins are proteins that kill bacteria as part of the innate immune system, our first line of defence against infection.

Although the findings do not immediately suggest new therapies for the disorder, they will improve our chances of identifying those who are most at risk and offer a new line of investigation to understand exactly how the defensin gene copy number variants lead to kidney disease. The team is already undertaking the next stage of research to further develop our knowledge.

The study is published in the journal Science Translational Medicine.