July 6, 2012 |
Scientists can now sequence the entire genome of a fetus from samples of a pregnant woman's blood, several recent studies have shown. It will come as no surprise that bioethicists are plenty interested in these developments and the benefits and thorny issues they will raise. The technology -- and the issues -- are discussed at length in a commentary this week in the journal Nature Medicine by Diana Bianchi of the Mother Infant Research Institute at Tufts Medical Center. Because a pregnant woman's blood carries pieces of fetal DNA, researchers can devise tests to tell with a high degree of certainty whether the fetus carries extra chromosomes (as an extra chromosome 21 in Down syndrome, for example)
February 3, 2011 |
Women may soon be able to find out very early in their pregnancies whether they are carrying a fetus with Down syndrome by offering a simple blood sample. The safe, noninvasive test would pose fewer risks to the mother and fetus than amniocentesis or chorionic villus sampling (CVS), the two tests currently used for prenatal diagnosis. It would also give women more time to decide what to do if a diagnosis of Down syndrome is made. Researchers from the Chinese University of Hong Kong have been working on the DNA-based test for a decade.
November 8, 2010 |
The evidence for bisphenol A's negative health effects keeps piling up. In a study released Monday in the Proceeding of the National Academy of Sciences, researchers at the Harvard Medical School reported that the chemical interferes with reproduction in the roundworm Caenorhabditis elegans . Scientists had already shown that bisphenol A, which is used in many plastics and in the linings of food cans , is associated with...
March 2, 2009 |
Wrinkles may betray our age externally, but our cells divulge their age -- and chronicle life's toll -- at the tips of our chromosomes. These tips, called telomeres, may also foretell our risk of early death. Telomeres are the protective caps made of repetitive chunks of DNA that keep the rest of the gene-laden chromosome from disastrously unraveling. But they lose bits of themselves with each cell division, so over a lifetime, like a counter, telomeres shorten.
September 3, 2005 |
The human Y chromosome -- the DNA chunk that makes a man a man -- has lost so many genes over time that some scientists have suspected it might disappear in 10 million years. But a new study says it'll stick around. Researchers found no sign of gene loss over the last 6 million years, suggesting the chromosome is "doing a pretty good job of maintaining itself," said researcher David Page of the Whitehead Institute for Biomedical Research in Cambridge, Mass.
March 24, 2005 |
Whenever a couple of curious kids play a behind-the-woodshed game of doctor, they discover that male and female bodies are different. Later, they learn that nature designed masculine and feminine organs for particular functions, although the specifics can be confusing even for adults. Roseanne Barr says husbands think a uterus is a tracking device. Why else would they ask their wives to locate a milk carton hiding in plain sight in the refrigerator?