The ultimate goal of stem-cell research is to replace malfunctioning cells with healthy ones--specially made for each patient--for people with, say, diabetes or a spinal-cord injury. Now researchers report they are one step closer to making that happen.
They have generated the first human stem cells using somatic cell nuclear transfer (SCNT), the same process that gave rise to Dolly in 1996 from a ewe's cell. One of the new lines came from a healthy adult, the other from a patient with Type 1 diabetes. The breakthrough suggests that it may be possible to grow patient-specific stem cells using SCNT. One catch: the technique normally involves swapping an egg cell's DNA for a donor adult cell's, then stimulating the egg to divide and create stem cells that contain the adult's genetic material. But in this case, scientists had to combine the two sets of DNA to get the process to work. The result--stem cells with triploid DNA--isn't clinically useful, but it's a scientific advance that heralds new potential.
How do bats see in total darkness? By echolocating with the help of superfast muscles. Bats' rapidly contracting vocal muscles allow them to emit up to 190 echolocating calls per second--known as a terminal buzz--helping them track fast-moving prey.
Percentage of low-income women who had a mammogram in the two years prior to 2008, compared with 73% of their wealthier peers
Birth Control That Raises the Risk of HIV?
Using an injectable form of hormonal birth control may double women's risk of contracting HIV, according to a large study of 3,800 African couples. And when used by HIV-positive women, the hormone shot doubled the risk of infection in their male partners, compared with using other forms of birth control or none at all. The biological reasons for the increased risks aren't clear, but the new findings are especially troubling given the dire health threats posed by unintended pregnancy and HIV/AIDS in sub-Saharan Africa. In that region, the contraceptive shot in question is among the most popular forms of birth control.
Why Parents Won't Follow The Rules
Despite reams of reassuring data, parents still agonize over whether routine childhood immunizations are safe--and a new study finds that more than 1 in 10 parents don't follow the recommended vaccination schedule set out by the federal government.
Instead, parents skip some vaccines, delay others or unnecessarily spread out needed doses. Their primary reason: enduring concern over the debunked link between autism and the measles, mumps and rubella vaccine.
More concerning, however, is the study's finding that even among those parents who followed the government's recommended schedule, 20% did so reluctantly, saying they didn't believe it was the best or safest plan for dispensing the shots their kids need.
Sources: Nature; Science; Pediatrics; Lancet Infectious Diseases; CA: Cancer Journal for Clinicians