Thursday, August 18, 2005
Fetuses, cold soup and the bar at the center of the galaxy
August 18, 2005
Burning to stir up the abortion controversy--Here we go again. A group of Swiss scientists report in Lancet [subscription required] that they have used human fetal cells as a form of bandage to treat serious burns in children. The bandage was derived from the skin cells of an aborted fetus and proved, in the test, far superior in encouraging healing than skin grafts. Keeping in mind that the sample size is very small, eight children, the results still are impressive because of the context. Normally, burns are treated by taking skin from part of the patient that was not burned, and grafting it over the burns. That hurts like hell, often leaves serious scars, and doesn’t always work. In this study, scientists at the University Hospital of Lausanne, took artificial fetal skin, grown from a postage-stamp sized sample of skin from a fetus aborted three years earlier. The goal was to use the artificial skin to cover the wounds, just as a graft would. That’s not what happened. The new skin had to be replaced every several days because it dissolved, but the doctors found that the skin restored the damaged tissue which regenerated and healed the wounds. The experiment needs to be replicated and certainly requires tests on a larger number of patients before any real conclusions can be reached--and those experiments won’t happen in the U.S. They would be illegal.
Waiter, there’s life in my soup--Scientists have long puzzled over the inelegance of the human genome. There’s a lot of junk in it, stuff we don’t seem to need and doesn’t appear to serve any purpose, and it seems unnecessarily complex. A group of British scientists [hey, did you notice, science actually gets done in other countries?] think they have an explanation: life formed in hot soup that eventually cooled down. The theory speaks to a 40-year-old puzzle--why does the DNA vocabulary contain 64-three-letter words (codons), when they translate into only 20 amino acids. Seems sloppy and inefficient. Several codons even translate into the same amino acid. The researchers, from the University of Bath reporting in the Journal of Molecular Evolution [I always have it by my bedside], working on an idea from Francis Crick, suggest that the three-letter code evolved from a simpler two-letter code. The original code involved reading only two of the three letters--the first two or the last two. Two amino acids excluded from the doublet system, glutamine and asparagine, appear to be late comers. Neither can hold their molecules together in high temperatures, so the researcher theorize they formed after the hot soup cooled down, complicating the rise of life.
So set ‘em up Joe, I’ve got a little story I want you to know--The bar at the center of the galaxy sounds like a Douglas Adams sequel but it isn’t. It’s a odd-shaped cluster of stars. Long and narrow (we are using relative terms here), it cuts through the Milky Way and is even bigger than anyone thought. Keep in mind, this is really huge: 27,000 light years in length, about 7,000 light years longer than originally thought. It’s comprised of old and red stars, according to researchers at the University of Wisconsin-Madison [I thought I’d throw in some American science here so everyone would feel better]. It sits at a 45-degree angle between our sun and the center of the galaxy and is a structure considered fairly rare in the known universe. It was found by the orbiting Spitzer Space Telescope. Most astronomers thought the center of the galaxy was spiral. Nope. There’s a bar there. Don’t panic.