World Bulletin/News Desk
Egg cells can repair themselves from damage caused by radiation far better than doctors ever thought, a finding researchers say gives fresh hope in protecting women undergoing cancer therapy from infertility.
Although the experiments have only been in mice, researchers believe they have relevance for female cancer patients and women who suffer premature menopause, a condition that puts them at risk of early infertility, osteoporosis and heart disease.
In a paper to be published in the November 9 issue of the journal Molecular Cell, scientists in Australia found that egg cells, or oocytes, are killed not by radiation, but by two proteins -- puma and noxa -- which snap into action when they detect DNA damage to egg cells.
In experiments using mice that did not carry these proteins, the scientists found that their eggs survived radiation and they went on to produce normal offspring.
"This is very exciting. It means if you get rid of those proteins that kill, the oocytes or specialised egg cells can actually repair their DNA and that has never been known before," said lead author Clare Scott, an associate professor and oncologist at The Royal Melbourne and Royal Women's Hospitals.
Between 50 to 80 percent of eggs survived in these mice.
"These were enough to result in normal fertility in those mice and they could produce normal pups. Those pups went on to be fertile themselves and lived a normal lifespan with no evidence of tumours or other abnormalities," she said by telephone.
Scott's colleagues are conducting similar trials on human egg cells to see if the two proteins work in the same way. If all goes well, they hope a drug can be designed to block the two proteins from killing egg cells.
"If that pans out well, then we would hope that a drug that could target (the protein) puma ... be provided as a therapy for three to six months during cancer therapy," Scott said.
Such a drug that blocks the action of the proteins could possibly prevent premature menopause or infertility, she added.
"In a woman, premature menopause is caused by (early) death of specialised egg cells. And if you can get specialised egg cells to survive, then premature menopause won't occur."
Guinea's President Alpha Conde announced new emergency measures in Ebola fight on Saturday
'Meetings happened. Action didn’t,' says Medecins Sans Frontieres report.
WHO said that on many levels, the world is better prepared now than ever before for aflu pandemic
Myanmar health officals say an outbreak of H5N1 bird flu in Mandalay
Tokyo Electric said it has been aware since last spring that radiation levels in water running in one of the plant gutters rise when it rains
Safe drinking water is available at about one-third of the level it was before the conflict erupted nearly five years ago, and supplies are cut-off to punish civilians at times
Elephants in Angola, which suffered decades of civil war, have been observed avoiding heavily-mined areas, suggesting their trunks were warning them to stay away.
Favipiravir halved death rate among some to 15 pct, but WHO says more research required on drug
The first medicine containing stem cells to treat a rare condition caused by burns to the eye has approved.
940 parasite samplescollected at 55 malaria treatment centres across Myanmar and its border regions. They found that almost 40 percent of the samples had mutations in their so-called kelch gene, K13 -- a known genetic signal of artemisinin drug resistance.
Yaws is known to be prevalent in 12 countries in areas where people have little access to healthcare, mainly in West and Central Africa, Asia and the Pacific Islands.
In the past few years, Nepal has seen the numbers of endangered species, such as the Royal Bengal tiger or the one-horned rhino, rise.
The investment would represent as little as 0.1 percent of current national health spending of the low and middle-income countries affected by NTD.
Nearly 1,000 abandoned California sea lions have washed ashore this year in what rehabilitation centers say is a growing crisis for the animals.
West Africa cases of Ebola show the first decrease in three weeks.
"Marijuana fools the brain's feeding system."scientist Tamas Horvath said.