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."
The Ministry of Environmental Protection found that 82.8 percent of the contaminated samples contained toxic inorganic pollutants, including cadmium, mercury, arsenic, chromium and lead.
Pakistan's army will join campaign to eradicate polio.
Instead of testing one drug at a time, a novel lung cancer study announced will allow British researchers to test up to 14 drugs from AstraZeneca and Pfizer at the same time within one trial
Australian Immigration Minister Scott Morrison's office said that medical officers at the centre had confirmed three cases of the potentially fatal tropical disease, which is transmitted by mosquitoes
The International Court of Justice (ICJ) last month ordered a halt to its annual hunts in the Southern Ocean, prompting Japan to cancel its 2014-2015 Antarctic hunt, the programme's mainstay, as it pledged to abide by the ruling
Researchers said they have identified a protein on the egg cell's surface that interacts with another protein on the surface of a sperm cell, allowing the two cells to join
The Crimean-Congo haemorrhagic fever (CCHF) virus was found in the person's blood who died on Sunday in Istanbul.
Authorities said a cancer-inducing chemical had been found in tap water supplied by the firm at 20 times above national safety levels, state media said
Ebola is a contagious disease for which there is no known treatment or cure.
The central government has identified the heavily industrialised Beijing-Hebei-Tianjin region as one of the main fronts in its war against pollution
The findings of the study and the likely changes to the food chain will be of concern to millions in the tropics who depend on coral reefs for food security and livelihoods.
More compact city designs that cut commutes, insulation to save energy, better public transport, cycle lanes and pedestrian areas can all cut emissions, mainly from fossil fuels.
Along with Saudi Arabia, cases of MERS have so far been reported in Qatar, the United Arab Emirates, Tunisia, Jordan and Oman.
The proposed establishment of an African Center for Disease Control and Prevention, as well as proposals for a centralized regulatory system for medical products, is expected to feature on the conference agenda.
The report, endorsed by governments, is meant as the main scientific guide for nations working on a U.N. deal to be agreed in late 2015 to rein in world greenhouse gas emissions
MERS, which emerged in the Middle East in 2012, is from the same family as the SARS virus and can cause coughing, fever and pneumonia.