The Malaysian Insider :: Features
The Malaysian Insider :: Features |
| Men with more brothers found to have faster sperm Posted: 21 Dec 2012 07:20 AM PST  Men with more brothers than sisters may have enhanced fertility, a new study suggests. — AFP pic Scientists from the University of Sheffield in the UK and Brown University in the US assessed the fertility of 500 men, and found that sperm swimming speed correlated with family makeup. The findings, published in the Asian Journal of Andrology, supports the theory that men with strong fertility are more likely to father boys. "We found the greater number of brothers rather than sisters a man has, the faster his sperm is, increasing the likelihood of fertility," says Dr Allan Pacey, one of the researchers. "Lots of brothers is also an indication that the man's parents have strong male fertility genes, and they would then be passed on to the son." Still, men with a lot of sisters needn't worry, and the scientists also didn't measure whether women with sisters were linked to enhanced fertility. "This is certainly not a smoking gun as a reason for infertility in men," said Dr. Jim Mossman, study leader and postdoctoral researcher at Brown University, according to the UK's Daily Mail on Wednesday. "However, it would be interesting to test whether the same relationships are observed in other human populations as well as in other species. Likewise, would we observe similar associations when looking at female fertility?" — AFP/Relaxnews |
| Long-lived bats offer clues on diseases, aging Posted: 21 Dec 2012 07:13 AM PST  A study finds that their highly evolved genes which give bats their superior immune system also enable them to fly. — AFP pic Studying the DNA of two distant bat species, the scientists discovered how genes dealing with the bats' immune system had undergone the most rapid change. This may explain why they are relatively free of disease and live exceptionally long lives compared with other mammals of similar size, such as the rat, said Professor Lin-Fa Wang, an infectious disease expert at the Duke-NUS Graduate Medical School in Singapore who led the multi-centre study. "We are not saying bats never get sick or never get infections. What we are saying is they handle infections a lot better," Wang said in a telephone interview. What was missing from both species of bats was a gene segment known to trigger extreme, and potentially fatal, immune reactions to infections, called the cytokine storm. Cytokine storms end up killing not only offending viruses in the body, but the host's own cells and tissues too. "Viruses rarely kill the host. The killing comes from the host's immune response. So it looks like what bats are doing is depress the inflammation (cytokine storm). If we can learn that, we can design drugs to minimise the inflammation damage and control viral infection," Wang said. The study, which saw the participation of researchers from China, Denmark, Australia and the United States, was published today in the journal Science. Compared with other mammals of similar size, bats live a long time, with lifespans of between 20 and 40 years. Rats live between 2 and 3 years, on average. IMMUNE GENES LINKED TO FLIGHT Interestingly, Wang and his colleagues found that the highly evolved genes that give bats their superior immune system also enable them to fly. Out of more than 5,000 types of mammals on the planet, bats are the only one capable of sustained flight and some species can fly more than 1,000 km in a single night. Such intense physical exertion is known to produce toxic "free radicals" that cause tissue damage and it is these same genes that give the bat the ability to repair itself, Wang said. "What we found was the genes that evolved fastest were genes involved in repairing DNA damage. That makes sense ... because when you fly, metabolism goes up and it generates free radicals that are toxic to cells," Wang said. "Because bats fly, they (would have had) to evolve and adapt ... to get genes that can repair DNA damage." Wang said we have much to learn from the bat, which has evolved to avoid disease and live exceptionally long lives. "Cancer, ageing and infectious disease, these are the three major areas of concern for people," he said. "We have studied rats for 150 years to understand how to do better in these three areas. Now we have a system, the bat, that has done very well in evolution. We can learn from the bat. With modern techniques, we can design new drugs to slow down the ageing process, treat cancer, fight infections." — Reuters |
| You are subscribed to email updates from The Malaysian Insider :: Features To stop receiving these emails, you may unsubscribe now. | Email delivery powered by Google |
| Google Inc., 20 West Kinzie, Chicago IL USA 60610 | |
0 ulasan:
Catat Ulasan